Biobanks serve as vital repositories for biological specimens and associated clinical data, enabling large-scale research to advance medical knowledge. Saudi Arabia presents a unique setting for such research due to its rapidly growing, youthful, and genetically homogeneous population shaped by high rates of consanguinity. Concurrently, the country faces a swift lifestyle transition contributing to a high prevalence of chronic diseases such as obesity, diabetes, and cardiovascular conditions. The Saudi Biobank Center was established to leverage these unique demographic and genetic characteristics to support precision medicine and public health initiatives aligned with national development goals. It represents a landmark resource for biomedical research in the Middle East region, providing a large-scale, well-characterized cohort that addresses a critical gap in global biobanking diversity. Its comprehensive design, robust infrastructure, and strategic vision position it to make significant contributions to understanding the genetic, environmental, and lifestyle determinants of health and disease. Continued expansion and collaboration will enhance its impact on precision medicine and public health, both regionally and globally. In this article, we present a comprehensive description of the structure, design, and methodology of the Saudi Biobank project. In a companion article, we will report the baseline demographic and clinical characteristics of the inaugural Saudi Biobank cohort and outline the project’s strategic direction.

With the surge in scientific publication over the years, there is an exponential rise in predatory publishing. The aim of the current study was to assess predatory journals’ awareness among clinical and non-clinical researchers. A cross-sectional study was conducted in a tertiary care hospital, affiliated university and the research center. Both males/females, physicians, professors, researchers, students, working in a hospital, university or a research center were enrolled. The primary outcome was the awareness of predatory journals, and to identify the predictors of awareness. The estimated sample size was 369. The survey consisted of 33 questions divided into five sections: (i) General information (ii) Research publications (iii) Awareness of predatory journals (iv) Open access (v) Journal selection. The questions were either yes/no or 5-point Likert scale. An electronic survey design was used for data collection. Variables were compared by aware and unaware groups using chi-square test. Logistic regression analysis was utilized to identify the predictors of awareness. Statistical analyses were performed using SAS version 9.4. Of the total 328 respondents, females were 178(54.4

PURPOSEDiffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma worldwide and in Saudi Arabia. However, regional data on clinical characteristics and outcomes remain limited.METHODSThis multicenter retrospective cohort study included 516 patients age ≥14 years diagnosed with DLBCL between January 2016 and December 2023 at two tertiary hospitals in Saudi Arabia. Data on demographics, disease features, treatment, and outcomes were collected. Survival analysis was performed using Kaplan-Meier and Cox regression models.RESULTSThe median age at diagnosis was 60.5 years, with 53% of patients younger than 65 years. Most patients (77%) had advanced-stage disease. Rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone was the most commonly used first-line regimen, particularly in younger patients (95% v 62%). Complete remission rates were 74% in patients younger than 65 years and 66% in those 65 years and older (P = .09). Relapse or refractory disease occurred more frequently in older patients (40% v 27%, P = .0019). Two-year progression-free survival was 78% in younger patients and 64% in older patients (P = .004), while 2-year overall survival (OS) was 87% and 76%, respectively (P = .001). Age, performance status, comorbidities, MYC expression, and kidney involvement were significant predictors of OS.CONCLUSIONThis study provides valuable real-world insight into the clinical landscape of DLBCL in Saudi Arabia. Overall outcomes are consistent with international data, although older age and comorbidities remain associated with poorer prognosis. As advanced therapies such as chimeric antigen receptor T-cell therapy and bispecific antibodies become more available, further improvements in survival are expected. These findings underscore the need for a national lymphoma registry and continued investment in research infrastructure to guide evidence-based, personalized care.

Cancer is emerging as a leading cause of morbidity and mortality in Saudi Arabia, with the incidence projected to double in the next 20 years. The health-care system in the country has witnessed considerable reforms over the past four decades, resulting in better control of communicable and non-communicable diseases and, subsequently, longer life expectancies. The Health Sector Transformation Program, a part of the Saudi Vision 2030, aims to strengthen the prevention and control of non-communicable diseases including cancer, improve access to care, deliver high-quality care services, improve patients' quality of life, and increase support for research and innovation. This Series paper highlights the considerable progress of the national cancer control programme, identifying remaining challenges and future opportunities. We envision that this paper will inform the development of the next National Cancer Control Plan to be sustainable, evidence-based, integrated, patient-centred, and value-driven for society.

Introduction Inferior vena cava (IVC) filters are used to prevent pulmonary embolism (PE) in patients with venous thromboembolism (VTE) who cannot receive anticoagulation. However, their use has often extended beyond evidence-based indications. The American Society of Hematology (ASH) guidelines recommend against routine insertion of IVC filters in patients who are eligible for anticoagulation, advise against their use as primary prophylaxis in surgical patients, and emphasize prompt retrieval once anticoagulation can be safely resumed. The need of the project: At our institution, baseline analysis revealed that 27% of IVC filters were inserted without an appropriate indication based on our institutional guidelines, which are aligned with ASH recommendations. Additionally, 24% of filters were not retrieved. These patterns posed significant clinical risks for the patient as well as organizational concerns in the form of increased cost, inefficiency, and reputational harm. The aim : was to improve the use of IVC filters in accordance with evidence-based guidelines and to increase the rate of retrieval. Methods We applied the Harvard 7-step quality improvement methodology and iterative Plan–Do–Study–Act (PDSA) cycles to address both overuse and under retrieval of IVC filters. It was carried out across the three tertiary hospitals of the National Guard Health Affairs in Riyadh: King Abdulaziz Medical City, King Abdullah Specialized Children's Hospital, and the Women's Health Hospital. Outcomes were measured over two periods: a pre-intervention phase (March–September 2024) and a post-intervention phase (October 2024–May 2025). We used Fisher's exact test to assess statistical significance of pre-post differences. Statistical process control (SPC) charts were constructed to identify special cause variation using standard Western Electric rules. Based on these insights, we implemented four interventions: Establishment of guidelines with a policy restricting insertion decisions: Baseline data showed that hematology consultation was associated with significantly higher appropriateness of IVC filter insertion (92.3% vs. 70.6%).Based on this, a policy requiring hematology approval prior to filter insertion was implemented. Automatic Consultation to IVC filter team Upon Filter Request To prevent avoidable IVC filter insertions, an automatic email alert system triggered by any filter order in the EHR was established. The thrombosis quality specialist receives the alert and informs the IVC filter team, who assess appropriateness, document a recommendation in the EHR before insertion, and communicate directly with the primary team to guide evidence-based decisions. Weekly Review by a Dedicated Team A dedicated IVC filter team—comprising a hematology consultant, fellow, and quality specialist —conducts weekly rounds to review all inpatients with filters. Each case is reassessed, a retrieval plan is documented, and the primary team is contacted to ensure implementation. Education of Healthcare Providers A structured education to physicians across departments involved in filter management. Result Following the intervention implemented in October 2024, the appropriateness of IVC filter insertion improved from 72.7% (48/66) to 91.4% (64/70), p = 0.0028. SPC analysis using a p-chart demonstrated special cause variation, triggered by Rule #3 (four out of five consecutive points above the +1 sigma line), Similarly, the retrieval rate among eligible patients increased from 76% (38/50) to 92.3% (48/52), p = 0.0062. SPC analysis showed special cause variation triggered by Rule #4 (eight consecutive points above the centerline), The median time to IVC filter retrieval decreased from 35 days (IQR 18–60) pre-intervention to 22 days (IQR 14–51) post-intervention; the difference did not reach statistical significance (p = 0.180, Mann–Whitney U test). Conclusion This quality improvement initiative successfully translated clinical guidelines into practice through a multifaceted strategy that included policy enforcement, automated consultation, structured case review, and targeted education. The intervention led to significant improvements in IVC filter appropriateness and timely retrieval, demonstrating the impact of coordinated, system-level efforts on patient safety and care quality. Next steps include sustaining the improvements locally and scaling the model to other centers to support broader guideline adherence in thrombosis care.

Introduction: Sickle cell disease (SCD) is a severe inherited hemoglobinopathy associated with significant morbidity and mortality. Hematopoietic cell transplantation (HCT) remains the only curative therapy for SCD, offering improved survival and quality of life. However, long-term complications of HCT, including the risk of secondary malignancies, remain a growing concern. Data on the incidence and outcomes of secondary malignancies in SCD patients post-HCT are limited. This study aims to describe our single-center experience and evaluate the occurrence and clinical characteristics of secondary malignancies following HCT in patients with SCD. Methods: We conducted a retrospective review of all patients with sickle cell disease (SCD) who underwent non-myeloablative conditioning with alemtuzumab and 300 cGy total body irradiation (TBI) for allogeneic hematopoietic cell transplantation (HCT) at our center. The study population included adolescent and adult patients aged ≥14 years who received a matched related donor (MRD) transplant. Patients who underwent myeloablative regimens or haploidentical transplants were excluded. The minimum duration of follow-up was one year. The primary objective was to assess and describe the occurrence of secondary malignancies in this cohort. Data were summarized using descriptive statistics, including counts, percentages, medians, and ranges. Result: A total of 391 patients with sickle cell disease underwent non-myeloablative allogeneic HCT. The median age at transplant was 25 years (range, 14–48), and 189 (48%) were male. The median follow-up was 1,242 days (range, 215–3,505), equivalent to approximately 3.4 years (range, 0.6–9.6 years). At last follow-up, 379 patients (97%) were alive, and 12 (3%) had died. Graft failure occurred in 24 patients (6.1%), and 14 underwent a second transplant. Among 391 patients who underwent non-myeloablative transplant for sickle cell disease, six (1.5%) developed secondary malignancies. The median age at diagnosis was 28.5 years (range: 21–43), and the median time to malignancy post-transplant was 2.4 years (range: 107 days–4.8 years). Diagnoses included MDS (n=2), MDS transformed to AML (n=1), CML (n=1), Philadelphia-positive ALL (n=1), and EBV-related PTLD with stage IV DLBCL (n=1). Summary of Patients with Secondary Malignancy Conclusion: Secondary malignancies following non-myeloablative hematopoietic stem cell transplantation in sickle cell disease patients are rare but clinically significant, with an observed incidence of 1.5% in our cohort. The rate of myeloid neoplasm in this large cohort with long follow up is 0.76%. The myeloid malignancy happen mainly in patients with GF and underlying leukemia predisposing condition. These findings highlight the importance of long-term surveillance and early molecular monitoring to detect clonal evolution and guide timely interventions. Further studies with larger cohorts are needed to better define risk factors and optimize prevention strategies. Patient Age Gender Time post-transplant Diagnosis Chimerism at Diagnosis Genetic Abnormalities Treatment Current Status Latest Chimerism HbS (%) 1 38 Male 4.8 years Graft failure MDS 0% del(7q31), del(13q14), ASXL1, PTPN11, RUNX1 2nd transplant (FluBu4), Azacitidine MDS recurrence post 2nd HCT 11% 4.1 2 29 Female 3.5 years Graft failurepost 2nd and 3rd HCTMDS 89.5% del(7q22), del(17p13) Azacitidine Active disease 63.3% 37 3 28 Female 2.4 years Ph+ ALL 46% t(9;22), del(9p21), TEL gene deletionBCR-ABL p190 Ponatinib + Blinatumomab ×4, HyperCVAD Part B MRD-negative remission 96.91% 26.2 4 24 Male 1.3 years CML 70% t(9;22), BCR-ABL p210 Dasatinib Remission 80% 38 5 21 Female 143 days EBV-related DLBCL (Stage IV) 56% None R-CHOP ×6 CR >1.5 yearsGraft failure 0% 43.8 (on transfusion) 6 43 Male 107 days MDS → AML (Li-Fraumeni) 35% Complex cytogenetics, TP53 mutation (homozygous) Induction chemo Died (fungal infection) – –

Introduction: Hospital-acquired venous thromboembolism (HA-VTE) is one of the most preventable causes of in-hospital death. Accurate detection is essential for evaluating the effectiveness of thromboprophylaxis and guiding safety interventions. At our institution, radiology reports are unstructured, limiting the effectiveness of automated tools. Prior efforts using ICD codes and trigger-based systems were inaccurate, and manual chart review—though more reliable—proved too labor-intensive for sustained surveillance. Moreover, existing systems do not reliably distinguish between acute and chronic pulmonary embolism (PE), which is critical for identifying new, hospital-acquired events. These limitations drove the development of an AI-based solution to extract and classify VTE events directly from radiology reports. Methodology Study Setting We included all CT pulmonary angiography (CTPA) reports from January 2024 to June 2025 at a tertiary National Guard hospital in Saudi Arabia. Each report was independently reviewed by two hematologists to determine the presence and chronicity (acute vs. chronic) of PE. Discrepancies were resolved through consensus discussion. Model Development We developed a semi-supervised active learning paradigm for PE detection and acute/chronic classification in radiology reports using BiomedNLP-PubMedBERT-base-uncased-abstract-fulltext as the backbone model. Initially, 1,934 labeled reports (approximately 10% positive) were used to fine-tune the transformer with a binary classification objective for PE detection. The dataset exhibited severe class imbalance, which we addressed using class-balanced loss weighting, AdamW optimization, and linear learning-rate scheduling with warmup. To overcome both limited labeled data and extreme class imbalance, we implemented a pool-based semi-supervised active learning approach: the fine-tuned model was applied to 5,000 unlabeled reports, strategically identifying potential positive cases. From these predictions, 745 high-confidence positive cases were manually reviewed and verified by clinical experts, then integrated into the training dataset. This resulted in a final curated dataset of 2,679 reports (35.27% positive), achieving a 387% increase in positive cases while improving class balance from 9:1 to 1.84:1 ratio. Results The final binary PE detection model achieved exceptional performance on the expanded dataset of 2,679 reports, with Accuracy = 99.47%, Precision = 98.65%, Recall = 100.00%, F1-score = 99.32%, and AUC = 99.99%. Only two false negative classifications were observed in binary detection. The acute/chronic PE classification model also showed strong generalization, achieving Accuracy = 96.48%, F1-score = 89.36%, Precision = 91.30%, Recall = 87.50% and AUC = 98.62% with only 5 misclassified cases. Discussion and Conclusion This study demonstrates the feasibility and effectiveness of a semi-supervised active learning framework for pulmonary embolism detection and chronicity classification from radiology reports. By combining transformer-based feature extraction with model-assisted case selection and expert validation, we developed a scalable strategy that addresses two fundamental challenges in clinical NLP: limited labeled data and class imbalance. The iterative training approach, beginning with a small, imbalanced dataset and enriched through targeted sampling from a large unlabeled pool, enabled a 387% increase in positive case representation (from 10% to 35.27%) while requiring manual review of only 14.9% of the unlabeled data. This substantially improved class balance and model performance with minimal annotation burden. To our knowledge, this is the first application of a semi-supervised active learning strategy in radiology report classification for PE, particularly one that captures both acute and chronic status. Compared to prior approaches relying on rule-based heuristics or fully supervised learning, our method achieved superior performance with far less labeled data. Our AI-based tool accurately detects hospital-acquired PE from unstructured radiology reports, addressing key limitations of existing surveillance methods. In addition to binary detection, it classifies the chronicity of PE, enabling more precise identification of hospital-acquired events. Future work will extend this approach to lower limb DVT, enable real-time clinical integration, and support prediction of hospital-acquired VTE to guide prevention strategies.

Background: Discontinuation of TKI therapy and treatment-free remission (TFR) have become new goals for chronic- phase chronic myeloid leukemia (CP-CML). The aim of this study was to estimate the TFR post discontinuation of TKI therapy at 3 tertiary-care centers. Patients and Methods: CP-CML patients aged >= 16 years who had an attempt to discontinue TKI therapy till June 2022, were eligible. The collected data included patients' demographics, prognostic score, type and duration of TKI therapy, response dates, relapse dates, response to re-initiation of TKI therapy, and risk factors for relapse. Results: Fifty-five patients (35, 63.6% females) with a median age of 40 (range 16-74) years at diagnosis discontinued therapy. Forty-eight (87.3%) patients received imatinib as first line therapy. Twenty-nine (52.7%) patients were receiving imatinib at the time of TKI-discontinuation. Median time from diagnosis to TKI discontinuation was 86 months (IQR 60;132) and median duration of TKI therapy after achieving DMR was 66 months (IQR 47;114). After a median follow up of 34 (IQR 12;68) months, 15 (27.3%) patients relapsed. Median time to relapse was 5 months (range 2-38). Most of the relapses occurred during the first 6 months except 3 (20%) patients. All the relapsed patients achieved MMR after a median of 3 (range 2-6) months after restarting TKI therapy. None of the patients progressed to advanced-phase. Conclusion: Our experience confirms that discontinuation of TKI therapy in CP-CML patients is feasible and safe in routine clinical practice, and can achieve TFR in more than two-third of carefully selected patients.

Cancer is emerging as a leading cause of morbidity and mortality in Saudi Arabia, with the incidence projected double in the next 20 years. The health-care system in the country has witnessed considerable reforms over the past four decades, resulting in better control of communicable and non-communicable diseases and, subsequently, longer life expectancies. The Health Sector Transformation Program, a part of the Saudi Vision 2030, aims to strengthen the prevention and control of non-communicable diseases including cancer, improve access to care, deliver high-quality care services, improve patients' quality of life, and increase support for research and innovation. This Series paper highlights the considerable progress of the national cancer control programme, identifying remaining challenges and future opportunities. We envision that this paper will inform the development of the next National Cancer Control Plan to be sustainable, evidence-based, integrated, patient-centred, and value-driven for society.

Introduction Venous thromboembolism (VTE) is a leading cause of preventable morbidity and mortality among hospitalized surgical patients. Despite the availability of evidence-based guidelines, real-world adherence to appropriate VTE prophylaxis remains suboptimal. Need for the Project At our institution, baseline data from January to September 2024 revealed that only 37.8% of surgical inpatients received guideline-concordant VTE prophylaxis. This gap posed significant risks to patient safety and underscored the need for a structured intervention. Aim To improve the appropriateness of VTE prophylaxis in surgical patients through a multifaceted, system-level intervention. Methods The project was implemented across three tertiary hospitals under the National Guard Health Affairs in Riyadh: King Abdulaziz Medical City, King Abdullah Specialized Children's Hospital, and the Women's Health Hospital. All patients admitted under a surgical department for more than 48 hours were included, with no exclusions. We conducted iterative Plan–Do–Study–Act (PDSA) cycles as part of our quality improvement approach. The intervention began in October 2024 and included:Education of Healthcare Providers Targeted education sessions were delivered to surgical teams focusing on proper VTE prophylaxis indications, dosing, and patient-specific considerations such as weight and bleeding risk.Automated Data Extraction and Weekly Audit-Feedback Weekly automated reports were sent to the thrombosis quality specialist containing comprehensive data on all surgical inpatients, including weight, prophylaxis type and dose, and baseline characteristics. Manual chart audits were then conducted, and individualized feedback was emailed to the primary team to address deviations.EHR Pop-Up Alert with Embedded VTE Prophylaxis Algorithm A real-time decision-support alert was integrated into the EHR. It appears each time a provider orders VTE prophylaxis (heparin or enoxaparin), displaying the institutional algorithm to guide correct agent and dosing based on weight, renal function, and VTE risk. The pre-intervention period spanned January to September 2024, and the post-intervention period covered October 2024 to July 2025. Fisher's Exact Test was used for statistical analysis. Statistical Process Control (SPC) charts were constructed to assess process stability and identify special cause variation. Results Among 11,246 audited surgical inpatients, at baseline, the main reasons for inappropriate prophylaxis were: incorrect choice between pharmacological and non-pharmacological prophylaxis (22.4%), inappropriate selection of pharmacological agent—unfractionated heparin (UFH) vs. enoxaparin—based on renal function (65.7%), and incorrect dosing based on patient weight (11.9%). The appropriateness of VTE prophylaxis improved from 37.8% to 54.8% post-intervention (p < 0.0001). SPC charts revealed special cause variation starting in October 2024, with multiple Nelson Rules triggered (Rules 1, 2, 3, and 4), confirming a sustained improvement. Conclusion This quality improvement initiative significantly improved the appropriateness of VTE prophylaxis in surgical patients through a scalable, multifaceted approach. Real-time decision support, targeted education, and comprehensive audit-feedback contributed to a sustained improvement in adherence to prophylaxis guidelines. Future work will evaluate whether the intervention led to a reduction in actual VTE events, explore the use of artificial intelligence to predict risk and guide prophylaxis decisions, and focus on sustaining the improvement and scaling the model to other hospitals across the country.

Authors: Maryam Almutairi 1234, Mohammed AlHarbi1234, Abdullah Alsaleh1234, Mohsen Alzahrani1234, Bader Alahmari1234, Hind Salama1234, Abdulrahman Alraizah1234, Ayman Ibrahim1234, Mohammed Bakkar1234, Ayel Yahya1234, Khalid Aldosari1234, Sumayyah Altamimi1234, Abdul Rauf Ghori1234, Mazin Ahmed1234, Mohammed Snallah1234, Naveed Qureshi1234 May-Anne Mendoza124, Naila Shaheen124, Ayman Alhejazi1234 and Ahmed Alaskar1234King Abdullah International Medical Research CenterKing Saud bin Abdulaziz University for Health SciencesDepartment of Oncology, King Abdulaziz Medical City, Riyadh, Ministry of the National Guard, Health AffairsSaudi Society of Blood and Marrow Transplantation (SSBMT)Department of Oncology, Prince Mohammed Medical City, Aljouf, Ministry of Health Corresponding Author: Ahmed Alaskar. Email: Background: ABVD (Adriamycin, Bleomycin, Vinblastine and Dacarbazine) is commonly used to treat Hodgkin lymphoma (HL) with a relatively lower risk of gonadal toxicity. However, lung toxicity particularly from Bleomycin leads to a common practice of omitting it with no or less effect on efficacy. ACVD (Adriamycin 25 mg/m², Cyclophosphamide 400 mg/m², Vinblastine 6 mg/m² (max 10 mg) and Dacarbazine 375 mg/m²) is a modified chemotherapy regimen from ABVD given IV on day 1 and day 15 and repeated every 28 days for 6 cycles, replacing bleomycin with low dose cyclophosphamide to further optimize efficacy and reduce pulmonary and gonadal toxicity. Brentuximab vedotin is added to ACVD (ACVD-BV) in those cases of positive PET following 2 cycles of ACVD. It has been used in advanced-stage HL (including stage II with bulky disease) as defined by Ann-Arbor staging system for HL . This study evaluates gonadotoxicity in adult HL patients treated with ACVD and ACVD-BV regimens. Methods: A retrospective cohort study was conducted among HL patients aged ≥17 years who received either ACVD (n=45) or ACVD-BV (n=11) chemotherapy protocols. Patients were followed for a median duration of 12 to 18 months from the initiation of treatment. Collected data included demographics, semen analysis results, natural return of menses and occurrence of natural pregnancy in female patients or spouses of male patients. Results: A total of 56 patients were included. 22 (39%) were females (mean age: 30 years, range 17–58) : 2 were post-menopausal so their gonadal function is unknown, 4 became pregnant and 16 resumed their menses spontaneously). 34 (61%) were males (mean age: 32.7 years, range 17–66) : 6 got their spouses pregnant, 20 had normal sperm analysis post-chemotherapy, 8 had no assessment so their gonadal function is unknown. Hence, in total 46 (82%) patients who underwent chemotherapy treatment using either ACVD or ACVD-BV have gained their gonadal function. No one reported to have failure of gonadal function, and 10(18%) with unknown status of their gonadal function. Sperm banking was performed for 18/34 (53%) males before starting chemotherapy, and only 3/22 (13.617%) females received leuprorelin (GnRH agonist) during the chemotherapy. Conclusion: This study shows a favorable advantage of ACVD /ACVD-BV chemotherapy in treating advanced-stage HL where majority of cases gained their gonadal functions. However, limitations include retrospective design, missing baseline gonadal function evaluation, particularly semen analyses, and inconsistent hormone level documentation. Fertility preservation strategies should be routinely discussed and documented prior to treatment initiation. Long-term prospective studies are recommended to more accurately assess gonadal function post-treatment.

In the published publication [...]

Background:The study aimed to perform a systematic review/meta-analysis of observational studies conducted in Saudi Arabia to identify the patterns of reported hematological parameters' reference intervals (RIs). Methods:The literature search was performed using PubMed and Google Scholar. Observational studies that reported hematological parameters measured under normal physiological conditions in apparently healthy individuals were included. Studies conducted on non-healthy individuals and/or on pregnant women; those related to basic science, methodology, physiology, and non-physiological state; and those conducted on patients having co-morbidities were excluded. Studies on the pediatric population were also excluded from the meta-analysis. The methodological quality was assessed using standard critical appraisal instruments from the Joanna Briggs Institute (JBI) Critical Appraisal Checklist. R software was used to run the random-effects models. The results were reported as weighted mean differences and 95% confidence intervals. The complete blood count (CBC) parameter means were compared by sex using an independent samples t-test. Results:In total, 12 studies were included in the systematic review from all regions-Central (n = 5), Western (n = 5), Southern (n = 1), and Northern (n = 1). A total of eight (66%) studies focused on adults, and four (33.3%) studies reported a sample of adolescents/children. In addition, seven studies were not included in the meta-analysis for the following reasons: three studies reported only white blood cell (WBC) parameters, two studies had only abstracts available, and two studies involved newborns. High heterogeneity was demonstrated for all hematological parameters: red blood cell (RBC), hemoglobin (Hb), or mean corpuscular hemoglobin concentration (MCHC) (I2 = 100%); mean corpuscular hemoglobin (MCH) or hematocrit (HCT) (I2 = 99%); platelet (PLT) or mean corpuscular volume (MCV) (I2 = 98%); and WBC (I2 = 90%). The RBC (p = 0.009) and Hb (p = 0.0006) values were higher in the male participants. The PLT (p = <0.0001) values were higher in female participants. The remaining hematological parameters' RIs were not statistically significant. Conclusion:The findings indicated some differences in the hematological parameters' RIs reported across Saudi Arabia. We recommend establishing hematological parameters' RIs based on the Saudi Arabian population to determine when to refer a patient with abnormal counts and to identify when to request further diagnostic work-up.

Background: Venous thromboembolism (VTE) can be the first clinical manifestation of occult cancer. In our prior work, we externally validated the RIETE and SOME scores in patients with unprovoked VTE and found their discriminative performance to be modest. In the same cohort, we developed a new two-variable logistic regression model—now named the Riyadh Score—using age and hemoglobin to estimate the probability of cancer within 12 months ( EHA 2025, 4159687, 4159683). However, internal validation and comparative analysis with existing scores had not yet been performed. Objective: To internally validate the Riyadh Score and compare its predictive performance against the RIETE and SOME scores in patients with unprovoked VTE. Method We conducted a retrospective cohort study of adult patients diagnosed with objectively confirmed unprovoked VTE at a tertiary academic center between January 2016 and December 2022. Unprovoked VTE was defined according to ISTH criteria and included pulmonary embolism, deep vein thrombosis, mesenteric vein thrombosis, and cerebral venous sinus thrombosis. Patients with active cancer at baseline, provoked VTE, or incomplete follow-up were excluded. Clinical and laboratory variables were obtained through manual chart review. The Riyadh Score was previously derived in this cohort using multivariable logistic regression and incorporates two continuous predictors: age and hemoglobin level. The predicted probability of cancer was calculated using the equation: Logit(p) = −3.6317 + 0.0325 × Age − 0.0088 × Hemoglobin, and converted to risk using the logistic function. For comparison, the RIETE and SOME scores were calculated based on their original point-based algorithms and analyzed as continuous variables. Model performance was assessed by evaluating discrimination using the area under the receiver operating characteristic curve (AUC) and calibration using the Brier score and calibration plots. Comparisons between models were performed using DeLong's test for correlated ROC curves. Statistical analyses were conducted using SPSS version 29.0.2. The study was approved by the Institutional Review Board, and informed consent was waived.Results: Among 1,680 patients screened, 1,230 were excluded due to provoked VTE and 23 because of loss of follow-up, leaving 427 patients with unprovoked VTE for analysis. The median age was 60 years (IQR 22), and 40% were male. Most patients (73%) had at least one comorbidity. Over 12 months, 19 patients (4.4%) were diagnosed with cancer, most commonly colorectal (31.6%), followed by lung (15.8%) and pancreatic cancer (10.5%). The majority (58%) had localized disease at diagnosis. Model Performance The Riyadh Score demonstrated good calibration, with predicted risks closely aligned with observed outcomes across deciles of risk. The Brier score was 0.043, indicating low overall prediction error, and the Hosmer–Lemeshow test showed no evidence of miscalibration (p = 0.29). In terms of discrimination, the Riyadh Score achieved an AUC of 0.72 (95% CI: 0.64–0.80). In comparison, the RIETE Score yielded an AUC of 0.60 (95% CI: 0.49–0.70) and the SOME Score an AUC of 0.60 (95% CI: 0.48–0.71). The Riyadh Score significantly outperformed both the RIETE and SOME Scores in predicting cancer risk, with p-values < 0.001 for both comparisons (DeLong's test). Conclusion: We developed a novel prediction model—the Riyadh Score—based on only two readily available variables (age and hemoglobin) to estimate the risk of occult cancer following unprovoked VTE. The score demonstrated good calibration and discrimination, outperforming the RIETE and SOME scores. Unlike prior tools, it provides a continuous risk estimate rather than relying on arbitrary dichotomized thresholds. To support future research and clinical exploration, a web-based calculator is available. Prospective external validation is warranted to confirm its generalizability and clinical impact.

Background: CT pulmonary angiography (CTPA) is the gold standard for diagnosing pulmonary embolism (PE), yet inconsistencies in reporting may compromise diagnostic accuracy and patient safety. At our institution, CTPA reports are unstructured narrative text, and informal observations raised concern about diagnostic uncertainty, possible overdiagnosis of small subsegmental PE (SSPE), and internal inconsistencies within reports. We conducted this structured quality review to evaluate the prevalence and nature of these three diagnostic vulnerabilities: uncertainty in diagnosis, identification of SSPE, and reporting discrepancies. Methods: We conducted a retrospective quality review of all quantitative CTPA studies performed at our institution between February and June 2025. Each report was assessed to determine PE presence, chronicity (acute, chronic, acute on chronic), and anatomical location (subsegmental vs. more proximal). Two independent hematologists reviewed all reports, with discrepancies resolved by consensus. The goal was to quantify the frequency and characteristics of three diagnostic vulnerabilities: diagnostic uncertainty, SSPE, and reporting inconsistencies. Diagnostic uncertainty was defined as any report where the radiologist explicitly stated that segmental or more proximal PE could not be excluded, without a definitive conclusion. Reporting discrepancy was defined as discordance within a single report between the body and the impression in any of the following: (1) presence or absence of PE, (2) chronicity classification (acute vs. chronic), (3) anatomical location (SSPE vs. more proximal). The study was approved by the Institutional Review Board, and informed consent was waived Results: A total of 1,800 CTPA studies were reviewed. Of these, 226 (12.6%) were positive for PE and 1,537 (85.4%) were negative. Among positive cases, 162 (71.7%) were acute, 50 (22.1%) chronic, and 14 (6.2%) acute on chronic. Diagnostic Uncertainty: Uncertainty was identified in 37 studies (2.1%) where radiologists explicitly stated inability to exclude segmental or more proximal PE. Small Subsegmental PE (SSPE): SSPE was reported in 38 cases (16.8% of PE-positive). Of these, 34 patients (89.5%) were anticoagulated, 9 (23.7%) were admitted, and 1 (2.6%) experienced a bleeding event. Reporting Discrepancies: Seven reports (3.1%) exhibited internal inconsistencies between the body and impression: 3 related to chronicity, 2 to anatomical location, and 2 to presence or absence of PE. Conclusion: Our findings reveal a triple threat to diagnostic safety in CTPA: diagnostic uncertainty, SSPE, and reporting discrepancies. Diagnostic uncertainty poses risks of both delayed and missed diagnoses. We observed a higher-than-reported rate of SSPE, which may signal potential overdiagnosis, with consequences including unnecessary anticoagulation, bleeding complications, and avoidable hospital admissions. Internal discrepancies within reports may lead to inappropriate management and erode clinician trust. These findings underscore the need for structured reporting, standardized diagnostic terminology, and multidisciplinary oversight to enhance reliability and safeguard patient outcomes.

Introduction: Cytomegalovirus (CMV) reactivation remains a significant complication following allogeneic hematopoietic-cell transplantation (allo-HCT), particularly in regions with high CMV endemicity. Letermovir, a CMV-specific antiviral agent, has emerged as a promising prophylactic strategy to mitigate CMV-related morbidity and mortality. This study presents real-world evidence evaluating the effectiveness of letermovir prophylaxis among allo-HCT recipients in high endemic settings. Method: This was a retrospective cohort study conducted at a tertiary transplant center in a region with high CMV endemicity. The study included adult patients who underwent allogeneic hematopoietic-cell transplantation (allo-HCT) and were CMV-seropositive prior to transplant. Patients were categorized into two groups:Study Group: Patients at ultra-high risk for CMV reactivation—defined as those who received haploidentical or mismatched transplants, had R+/D− CMV serostatus, or received T-cell depletion with anti-thymocyte globulin (ATG) or alemtuzumab (Campath)—who received letermovir prophylaxis and completed at least one year of post-transplant follow-up.Control Group: Patients with similar risk profiles who did not receive letermovir prophylaxis but completed at least one year of follow-up. The primary objective was to assess the proportion of patients with clinically significant CMV infection (csCMVi) through Week 24 post-transplant among those without detectable CMV DNA at baseline. Secondary objectives included:Proportion of patients with csCMVi through Week 14Time to csCMVi through Week 24Transplant-related mortality (TRM)Graft failureIncidence and severity of graft-versus-host disease (GVHD) Clinical and laboratory data were collected from electronic medical records. CMV DNAemia was monitored using quantitative PCR. Statistical analyses included time-to-event methods and comparative statistics to evaluate outcomes between groups. Results: A total of 84 patients were included: 43 in the letermovir group and 41 in the control group. The median age was lower in the letermovir group (24 years; range 15–63) compared to the control group (31 years; range 17–63). Male patients comprised 60% of the letermovir group and 43% of the control group. CMV-seropositive donors were more frequent in the control group (100%) compared to letermovir group (72%). The most common indication for transplantation in the letermovir group was sickle cell disease or thalassemia (58%), while acute leukemia (AML/ALL) was more prevalent in the placebo group. Donor types were comparable, with haploidentical transplants being the most common in both groups. Peripheral blood was the predominant stem cell source. Reduced-intensity conditioning (RIC) was used more frequently in the letermovir group (60%) than in the control group (46%). T-cell depletion strategies varied, with higher use of ATG and Campath in the letermovir group, while PTCy was more common in the control group. GVHD requiring steroid treatment occurred in 15 patients in the letermovir group and 12 in the control group. Clinically significant CMV infection by Week 24 occurred in 37% of the Letermovir group compared to 68% in the control group (p = 0.0051). At Week 14, the rates were 20.5% and 65.8%, respectively (p = 0.0084). CMV recurrence was noted in 2.3% of Letermovir patients and 10% of cotorol patients (p = 0.1965), while CMV disease occurred only in the control group (5%) (p = 0.2352). Transplant-related mortality (TRM) was 11% in the Letermovir group and 7% in the control group (p = 0.7133). Conclusion: In this real-world retrospective study conducted in a high CMV endemic region, letermovir prophylaxis significantly reduced the incidence of clinically significant CMV infection in ultra-high-risk allogeneic hematopoietic-cell transplant recipients. Patients receiving letermovir demonstrated lower rates of CMV infection at both Week 14 and Week 24 post-transplant, with delayed onset of CMV reactivation and no observed CMV disease. These findings support the effectiveness of letermovir in mitigating CMV-related complications in high-risk populations and reinforce its role as a valuable component of post-transplant antiviral prophylaxis strategies.

BackgroundSickle cell disease (SCD) is an inherited blood disorder characterized by chronic hemolysis, inflammation, and vaso-occlusive crises (VOC), leading to multiple complications and reduced life expectancy in affected individuals. Limited effective treatment options are currently available; however, recent genomic findings from underrepresented populations (Saudi Arabians) have offered new hope for predicting molecularly guided treatments. This study aimed to identify approved drugs suitable for repurposing based on their interactions with SCD-associated genetic variants and to discover novel druggable targets within genetic pathways linked to disease severity by utilizing genome-wide association study (GWAS) data from Saudi SCD patients.MethodsBioinformatic pipelines were used to evaluate drug-gene interactions and identify potential therapeutic targets based on GWAS data derived from the Saudi population. Approved drugs were suggested for repurposing according to their interactions with genes known to impact SCD pathophysiology, using the Drug-Gene Interaction Database (DGIdb 5.0). New drug targets were also proposed by assessing the simulated binding pockets of gene products, using 3D protein structures from the Protein Data Bank (PDB) and the AlphaFold database. Molecules with higher druggability scores, as estimated by the DoGSiteScorer database, were predicted to have a higher success rate for new SCD treatment development.ResultsOur analysis identified 78 approved medications with potential for repurposing in SCD; this list was narrowed to 21 candidates based on safety profiles and interactions with key genetic pathways. Among these, simvastatin, allopurinol, omalizumab, canakinumab, and etanercept were suggested as the most promising agents. Furthermore, novel drug targets encoded by olfactory receptor (OR) gene clusters (OR51V1, OR52A1, OR52A5, OR51B5, and OR51S1), TRIM genes, SIDT2, and CADM3 displayed high druggability scores.ConclusionThis study provides a robust framework for drug repurposing and novel drug discovery in SCD, particularly tailored to the Saudi population. The findings underscore the potential of leveraging genomic data to identify targeted therapies, offering a pathway to more personalized and effective treatments for SCD patients. Future clinical trials are essential to validate these findings and translate them into clinical practice.