AIMS:Measurable residual disease (MRD) is a key prognostic marker for patient survival. This study evaluated concordance between 10-color flow cytometry and next-generation sequencing (NGS)-based immunoglobulin heavy chain (IGH) gene assays for MRD detection and to assess prognostic significance in adult B-cell acute lymphoblastic leukemia (B-ALL). METHODS:This multicenter prospective study enrolled 51 patients with newly diagnosed B-ALL. Bone marrow samples were obtained at diagnosis, post-induction (1 month), and post-early consolidation (3 months). Flow cytometry and NGS-IGH were performed at three timepoints to assess MRD B-ALL. RESULTS:Patients were classified as high risk according to white blood cell count and cytogenetic features in 37.3% and 64.7% of patients, respectively. Treatment protocols included pediatric-inspired regimens (41.2%), adult-ALL protocols (52.9%), and low-intensity chemotherapy. All 16 Philadelphia chromosome-positive patients received tyrosine kinase inhibitors. Twenty patients underwent allogeneic hematopoietic cell transplantation (HCT) in first complete remission (CR). Median relapse-free survival (RFS) and overall survival were 19 and 39 months, respectively. MRD negativity at 3 months by either method correlated with significantly superior RFS. Allogeneic HCT also conferred RFS benefit. MRD positive patients without HCT had the worst RFS. Flow cytometry MRD positivity at 3 months independently predicted inferior RFS (HR 3.81; 95% CI 1.01-14.43). The overall concordance between flow cytometry and NGS was 80.7%. CONCLUSION:MRD positivity at 3 months post-treatment strongly predicted relapse, supporting its use to guide therapeutic modifications of B-ALL. Apart from NGS-based IGH clonality assays, 10-color flow cytometry offers an alternative in resource-limited settings.

IntroductionDespite the development of advanced therapeutic approaches in the last two decades, acute myeloid leukemia (AML) has a poor prognosis, especially in older patients. The main causes of death are refractory/relapsed disease, fatal bleeding, or serious infection. A model to predict survival in patients with AML is necessary for clinicians to make decisions regarding appropriate treatment. In this study, we aimed to evaluate the predictive factors for death and generate a model to predict survival in patients with AML.MethodsWe conducted a multicenter prospective cohort study across nine tertiary medical care institutes in Thailand, enrolling patients aged ≥ 18 years with newly diagnosed AML between January 1, 2014, and December 31, 2023. Patients with acute promyelocytic leukemia were excluded. Multivariable Cox proportional hazards regression analyses identified the predictors of mortality, and the final model was constructed using backward stepwise regression with Akaike Information Criterion selection. Model performance was assessed using Harrell’s C-index and calibration plots, with internal validation performed via bootstrapping.ResultsA total of 1,055 patients were included. The median overall survival was 10.9 months, with a 10-year survival rate of 22.4%. Eight variables were independently associated with survival outcomes: age > 55 years, Eastern Cooperative Oncology Group performance status, tumor lysis syndrome, leukostasis, disseminated intravascular coagulation, white blood cell count, genetic risk, and type of induction therapy. The THAI-LEDGE model demonstrated a good discriminatory ability (C-index = 0.743) and satisfactory calibration. The internal validation yielded a C-index of 0.737, confirming the robustness of the model.ConclusionsThe THAI-LEDGE model performed well in predicting the survival of AML patients. However, external validation of the model in other ethnic populations and healthcare settings are necessary before widespread clinical implementation.

This study demonstrated the incidences of hospital-acquired colonization by extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E), carbapenem-resistant Enterobacterales (CRE), and vancomycin-resistant enterococci (VRE) of 22%, 8%, and 8% among hematologic malignancy patients. Difference in time to colonization detection between VRE (14 d) and ESBL-E and CRE (7 d) may inform appropriate surveillance measures.

BackgroundFLT3-ITD mutations are among the most common genetic alterations in acute myeloid leukemia (AML) and are associated with poor clinical outcomes. However, data from low- and middle-income countries remain limited. This study aimed to investigate the prevalence, clinical characteristics, treatment patterns, and outcomes of adult AML patients with FLT3-ITD mutations in Thailand.MethodsWe analyzed data from 360 adult patients with newly diagnosed AML, prospectively collected from 11 institutions nationwide between 2016 and 2023. FLT3-ITD mutational status, clinical features, response to therapy, and survival outcomes were compared between FLT3-ITD and FLT3-wild-type patients.ResultsFLT3-ITD mutations were detected in 28.1% of patients. FLT3-ITD patients had higher white blood cell counts, bone marrow blast percentages, and NPM1 co-mutations compared to wild-type FLT3. Induction chemotherapy rates were similar, but FLT3 inhibitor use was nearly absent. Complete remission was achieved in 55.7% of FLT3-ITD patients versus 66.5% in wild-type FLT3. Median overall survival was significantly shorter in the FLT3-ITD group (8.8 vs. 13.2 months, p=0.039), while relapse-free survival was not significantly different. Multivariable analysis confirmed FLT3-ITD mutation as an independent predictor of poor overall survival.ConclusionsIn this nationwide real-world study, FLT3-ITD AML was associated with inferior outcomes despite comparable induction therapy. Limited access to FLT3-targeted treatments and stem cell transplantation may contribute to these disparities. Our findings highlight the urgent need for expanding access to molecular testing and targeted therapies in resource-limited settings.

Introduction“AML with MECOM rearrangement” was recently categorized by WHO classification 2022 regardless of blast count, which included those present with MDS and AML into this group. We aim to explore frequency, clinical characteristics, and outcomes in this subtype among Thai myeloid neoplasms.MethodsMDS and AML data was collected from a multicenter study group. MDS and AML with MECOM rearrangements were analyzed and compared with other subtypes.ResultsA total of 15 cases with MECOM rearrangement were detected, 5/166 (3%) were MDS while 10/1082 (0.9%) were AML. Eleven of 15 cases (73%) were female. MDS and AML with MECOM rearrangement showed lower hemoglobin, but higher platelet counts compared to others. Three MDS with MECOM rearrangement patients received azacitidine-based regimens and achieved complete hematologic response. In AML cases receiving intensive chemotherapy, MECOM rearrangement subgroup showed lower complete response (CR) rate compared to others (0% vs. 39.6%). Of note, among 10 AML with MECOM rearrangement, 7 patients received intensive chemotherapy but none of them responded. When combining 5 MDS and 10 AML with MECOM rearrangements, survival rate is comparable to the adverse group of AML and the very high risk group MDS with a 1-year survival rate of 27.5% (Figure 1A and 1B).ConclusionsIn conclusion, MDS and AML with MECOM rearrangements are rare subtype, more common in female gender and associated with poor prognosis. Chemotherapy should be avoided, hypomethylating agent showed benefit. Novel therapy targeting MECOM gene should be further explored.

Universal antifungal treatment has been recommended among hematology patients during chemotherapy to prevent invasive aspergillosis (IA) in developed countries, but it remains a significant challenge in resource-limited settings. Identifying at-risk individuals could enhance clinical outcomes. A prospective pilot study was conducted at four Thai tertiary care hospitals from April 2021 to January 2023, aiming to assess the correlation and the potential of nasal wash galactomannan (GM) as an IA predictor in hematology patients. It enrolled all patients with acute myeloid leukemia (AML) requiring induction chemotherapy and those admitted for stem cell transplantation (SCT). Nasal wash fluid samples were collected for galactomannan testing and fungal culture to assess Aspergillus spp. colonization before chemotherapy. The study included 34 AML and SCT patients. Among them, 3/34 tested positive for Aspergillus spp. colonization via nasal wash fungal culture. After six months, 18 (52.9%) patients were diagnosed with IA—15/25 patients with AML and 3/9 SCT recipients. The traditional culture did not predict IA, whereas nasal wash fluid galactomannan cutoff value of 0.46 yielded a sensitivity of 40% and a specificity of 80% for predicting probable and possible IA in patients with AML. However, in the subgroup analysis, the test did not reveal any correlation with IA development. More extensive studies are needed to validate the optimal IA risk prediction strategy.

Introduction: B-lymphoblastic leukemia (B-ALL) is an aggressive hematologic malignancy. Chemotherapy has been the mainstay treatment for B-ALL, however, approximately 30% of adult B-ALL relapse after the treatment. Measurable residual disease (MRD) after intensive chemotherapy is one of predictors of disease relapse and inferior survival therefore being integrated into treatment scheme of B-ALL to individualize treatment for patients with B-ALL. Determining MRD status can be done by various methods. Multicolor flow cytometry has been widely integrated into clinical practice for MRD detection, however, there are certain technical limitations and variable sensitivity. Next-generation sequencing (NGS) detecting clonal rearrangement of immunoglobulin (Ig) gene has been an increasingly used technique with high sensitivity and unequivocal interpretation. However, an appropriate timepoint of Ig gene sequencing for MRD detection to correlate with clinical outcomes is not yet well validated. We aim to evaluate the role of MRD monitoring after intensive chemotherapy in adult B-ALL patients using Ig sequencing and its correlation with treatment outcomes. Methods: Newly diagnosed adult (age>15 years old) B-ALL patients from 4 university hospitals in Thailand between 2019 to 2023 were included (King Chulalongkorn Memorial Hospital, Thammasat university, Chiang Mai university and Ramathibodi hospital). DNA was extracted from bone marrow at the diagnosis, after the first and second cycle of chemotherapy (MRD1 and MRD2) and examined using NGS to analyze clonal rearrangement of Ig heavy chain (IGH) using LymphoTrack® IGHFR1 Assay (Invivoscribe) with IONS5 sequencer. Those that were negative for IGH clonality were further sequenced for clonal rearrangement of Immunoglobulin kappa light chain (IGK). Results: A total of 25 B-ALL patients were sequenced for clonality by IGH assay. IGH clonality was demonstrated at diagnosis in 22 patients (88%) which were subsequently examined for IgH MRD analysis (9 male and 13 female). The median age at diagnosis was 30.5 years old (15-66), with 11/22 (50%) age older than 30 years. Unfavorable karyotypes were observed in 8 patients including 6 cases (27%) with Philadelphia chromosome-positive. Sixty-eight percent (15/22) of the patients were categorized as a high-risk group. Chemotherapy regimens for induction were selected by local hematologists upon institutional preference. There were 11 patients who received adult ALL protocol (adult ALL and HyperCVAD regimen), while 11 patients received pediatric-inspired regimens. All patients with Philadelphia chromosomes-positive ALL received imatinib concomitantly with chemotherapy. All patients achieved morphological complete remission after the first and second cycle of chemotherapy. Eighteen and 17 cases were evaluated for MRD1 and MRD2 by IGH sequencing, respectively. Five patients (22.7%) underwent allogeneic stem cell transplantation. After a median follow-up of 12 months (range, 2-61 months), 11/22 (50%) had disease relapse. Patients with positive MRD by IGH sequencing after second cycle of chemotherapy were significantly correlated with relapse disease (n=11) or not achieved complete remission (n=1) (HR 9.5, 95%CI 1.1-81.4; p=0.04), while those with positive MRD after first cycle of chemotherapy were not associated with relapse disease (p=0.43). Conclusions: MRD detection using IGH NGS analysis can be applied for post-treatment response assessment of patients with B-ALL. Detection of IgH clonality after second cycle of chemotherapy correlates with inferior survival in B-ALL. Therefore, those patients should be considered for subsequent treatments, such as allogeneic stem cell transplantation or novel monoclonal antibody.

INTRODUCTION:Antithymocyte globulin (ATG) has been demonstrated to reduce the incidence of graft-versus-host disease (GVHD); however, it remains controversial whether these gains are offset by an increase in relapse. METHODS:We conducted a retrospective historical control study consisting of patients (n = 210) who underwent myeloablative allogeneic hematopoietic stem-cell transplantation (HSCT) from 2014 to 2020. RESULTS:The incidence of acute GVHD was lower in the ATG group (51.4%) than the non-ATG group (control) (70.0%, p = 0.010). The incidence of chronic GVHD was also lower in the ATG group at 1-year (36.4% vs. 62.9%, p < 0.001) and 2-year (40.0% vs. 65.7%, p < 0.001) post-HSCT. The mortality due to GVHD was higher in the control (18.5%) than the ATG group (4.3%; p = 0.024). The severe GVHD-relapse-free survival was higher in the ATG group (36.4%) than the control (12.9%; p < 0.001). Nevertheless, the 2-year overall survival was similar. CONCLUSION:Our results confirm the effectiveness of ATG in prevention of GVHD in the real-world setting and enhanced GVHD-free survival. An important result is the equalization of overall survival between the ATG and control groups at 1- and 2-year post-HSCT and implies that earlier GVHD-associated mortality may be offset by later relapse mortality producing similar overall survival over time.

Background MYC/BCL2 double expression (DE) is associated with poor prognosis in patients with diffuse large B-cell lymphoma (DLBCL) receiving rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP). This study aimed to determine whether the addition of DE to the National Comprehensive Cancer Network Internal Prognostic Index (NCCN-IPI) could improve the prediction of disease progression in patients with DLBCL treated with R-CHOP. Methods This confirmatory prognostic factor study retrospectively recruited patients with newly diagnosed DLBCL between January 1, 2014, and January 31, 2018, at Ramathibodi Hospital (RA) and Thammasat University Hospital (TU). The follow-up period ended on July 1, 2022. Tumors expressing MYC ≥ 40% and BCL2 ≥ 50% were classified as DE. We calculated the hazard ratios (HR) for progression-free survival (PFS) from the date of diagnosis to refractory disease, relapse, or death. Discrimination of the 5-year prediction was based on Cox models using Harrell’s concordance index (c-index). Results A total of 111 patients had DE (39%), NCCN-IPI (8%), and disease progression (46%). The NCCN-IPI adjusted HR of DE was 1.6 (95% confidence interval [CI]: 0.9–2.8; P = 0.117). The baseline NCCN-IPI c-index was 0.63. Adding DE to the NCCN-IPI slightly increased Harrell’s concordance index (c-index) to 0.66 ( P = 0.119). Conclusions Adding DE to the NCCN-IPI may not improve the prognostic value to an acceptable level in resource-limited settings. Multiple independent confirmatory studies from a large cohort of lymphoma registries have provided additional evidence for the clinical utility of DE.

Abstract Background Invasive aspergillosis (IA) is a common opportunistic infection in patients with acute myeloid leukemia (AML) and allogeneic stem cell transplant (SCT) recipients. Identifying at–risk patients may improve clinical outcomes when universal prophylactic therapy is not possible in a resource-limited setting. Aspergillus spp. colonization has been listed as a potential risk for infection development among patients with hematologic diseases, but this has not been explored in real-life clinical practice. Objectives To evaluate the correlation of Aspergillus spp. colonization and invasive aspergillosis development and to assess nasal wash galactomannan as a potential predictor for IA among AML patients and allogeneic SCT recipients. Methods A prospective pilot study at four tertiary care hospitals in Thailand was conducted from April 2021 to January 2023. All AML individuals requiring induction chemotherapy and patients admitted for a conditioning regimen for allogeneic SCT were enrolled. Nasal wash fluid was obtained for galactomannan and fungal culture to assess Aspergillus spp. colonization before chemotherapy. The patient’s demographic and relevant data were retrieved. All patients were monitored for IA development and the need for antifungal use for IA treatment. Results 25 AML patients and nine allogeneic SCT recipients were included. A nasal wash fungal culture positive for Aspergillus spp. was identified in 3/34 patients. Eighteen (52.9%) patients were diagnosed with invasive aspergillosis after a six-month follow-up, 15/25 among AML patients, and 3/9 among allogeneic SCT. 8 patients (23.5%) had nasal wash galactomannan >0.46, and 5/8 patients had IA. The cut-off value of nasal wash fluid galactomannan of 0.46 provided a sensitivity of 55.56% and specificity of 78.57% in diagnosing IA in AML patients. Conclusion The incidence of Aspergillus spp. colonization by the traditional culture-based method was low at treatment initiation and did not suggest future IA development in this study. However, nasal wash galactomannan may help predict future IA development in AML patients, but due to low sensitivity may limit its role in actual clinical practice at a larger scale. Further studies are needed to verify the best strategy to predict the risk of IA in this population. Disclosures All Authors: No reported disclosures

Allogeneic hematopoietic stem cell transplant (aHSCT) patients are well known to be at high risk of vitamin D (vit D) deficiency. This study assessed whether a loading dose (100,000 IU) of vitamin D3 pre-aHSCT could effectively achieve and maintain sufficient post-transplant vit D levels (serum total 25 hydroxy vitamin D (25(OH)D) ≥ 75nmol/L). Dual-energy X-ray absorptiometry (DXA) was also conducted for bone health evaluation. 74 patients were enrolled and randomly assigned, in a 1:1 ratio, either to the high vit D group (single loading dose (100,000 IU) plus 2,000 IU vit D3 daily) or the control group (2,000 IU vit D3 daily). Vit D levels were measured at three time points (baseline, day 30 and day 100 post-aHSCT). At baseline, fewer than 50% patients had a sufficient 25(OH)D (control: 42.9%; high vit D: 43.6%). The proportion of patients with sufficient 25(OH)D (nmol/L) was increased at day 30 and day 100, with a trend of higher proportion in the high vit D group at day 30 (high vit D vs. control: 89.7% vs. 74.3%, p = 0.08). The increased 25(OH)D was significantly higher in the high vit D group at day 30 (high vit D vs. control: 29±25.2 vs. 14 ±21.9, p = 0.01). Insufficient vit D level before transplant (baseline) was an independent risk factor for vit D insufficiency (serum 25(OH)D < 75nmol/L) post-aHSCT (OR = 4.16, p = 0.03). DXA suggested significant bone loss for total hip in both groups, and in the femoral neck for the control group only. In conclusion, single loading dose vitamin D3 significantly increased total 25(OH)D levels at day 30 post-transplant, and the intervention was especially beneficial for patients with baseline vit D insufficiency. We acknowledge that the primary outcome at day 100 post-aHSCT indicating superiority of loading dose versus daily dose supplementation was not met.

Kaposi Sarcoma is rare cancer associated with the coinfection of KSHV and HIV. However, the KSHV Inflammatory Cytokine Syndrome is even rarer diagnosed among Kaposi Sarcoma patients and has poor survival outcomes despite the treatment.

Objectives: AEFIs (adverse events following immunizations), especially ISRR ( immune stress related response) which can cause stroke-like symptoms may affect the vaccine roll-out campaign to prevent the coronavirus 2019 outbreak. Methods: This study aimed to describe the incidence and clinical characteristics of neurological AEFIs and strokelike symptoms associated with ISRR after COVID-19 vaccination. Characteristics of ISRR were compared to minor ischemic stroke patients during the same period of the study. During March to September 2021, we retrospectively collected data of participants aged & GE; 18 years who received COVID-19 vaccine and developed AEFIs from Thammasat university vaccination center (TUVC). Data of neurological AEFIs patients and minor ischemic stroke patients were collected from hospital electronic medical record system. Results: COVID-19 vaccine were administered at TUVC for 245,799 doses. AEFIs were reported in 129,652 instances (52.6%). ChADOx-1 nCoV-19 viral vector vaccine has the most frequent occurrence of AEFIs (58.0%), and neurological AEFIs (12.6%). 83% of neurological AEFI was headache. Most were mild and did not need medical attention. Of 119 patients who received COVID-19 vaccine from anywhere with neurological AEFIs and presented to TUH, ISRR was diagnosed in 107 patients (89.9%) and all patients who has follow-up data (30.8%) showed clinical improvement. In comparison with minor ischemic stroke (116 patients), ISRR patients had significantly less ataxia, facial weakness, weakness of arm/leg and speech disturbances (P < 0.001). Conclusion: The incidence of neurological AEFIs after COVID-19 vaccination was higher among recipients of ChAdOx-1 nCoV-19 vaccine (12.6%) than inactivated vaccine (6.2%) and mRNA vaccine (7.5%). However, most neurological AEFIs were ISRR, had mild severity and resolved within 30 days. Stroke-like symptoms occurred less frequently than patients with minor ischemic stroke.

INTRODUCTION:Acute promyelocytic leukemia (APL) is a distinct subtype of acute myeloid leukemia (AML) with a unique clinical presentation and prognosis. This study aimed to investigate the epidemiology, clinical characteristics, treatments, and clinical outcomes of Thai APL patients dominantly treated with all-trans-retinoic acid (ATRA) combined with a chemotherapy-based therapy. METHODS:This was an eight-year prospective, observational study from nine academic hospitals in the Thai Acute Leukemia Working Group (TALWG) of the Thai Society of Hematology, which included newly diagnosed Thai APL patients, aged 18 years or older. The web-based registration collected baseline charateristic, and clinical outcomes. RESULTS:From 992 newly diagnosed AML patients, 79 APL patients were enrolled in this study. Almost all subjects were de novo APL (94.9%), while the others were therapy-related APL. The commonest clinical presentation was disseminated intravascular coagulation (38%). One-third of the patients were categorized as high risk according to the initial WBC. Almost all patients received ATRA combined with idarubicin regimen. The complete response rate was as high as 95.7%, which translated into excellent four-year overall survival (OS) (75.6%) and four-year leukemia-free survival (LFS) (75.4%). The multivariate analysis demonstrated that the older age and WBC count >20 × 109/L conferred a significantly unfavorable OS with the hazard ratios of 3.03 (95% confidence interval [CI]: 1.14-8.05) and 4.18 (95%CI: 1.69-10.35), respectively. Similarly, these two parameters remained independent of the poor prognosis factors for LFS. CONCLUSION:This report confirmed that APL had a favorable prognosis. However, advanced age and high WBC count >20 × 109/L contributed to a worse outcome. ABBREVIATIONS:APL; acute promyelocytic leukemia; ATRA; all-transretinoic acid; CR; complete remission; DS; differentiation syndrome; ECOG; Eastern Cooperative Oncology Group; ED; early death; HR; hazard ratio; IQR; interquartile range; LFS; leukemia-free survival; OS; overall survival; WBC; white blood cell.

Early detection of dengue virus infection will lead to proper management and reduction in morbidity/mortality. Monocyte distribution width (MDW) was recently approved for use in the early detection of sepsis. Because monocytes are involved in the innate immune system against viral infection, we sought to determine changes in MDW to develop and validate a new predictive score for dengue viral infection. This study included patients who presented with symptoms or signs related to dengue infection and who had a complete blood count and dengue investigation performed during September 2019 to May 2020. The proportion of dengue infection was 29.5% in the current study. The MDW was significantly higher in dengue infection (median, 29.7 versus 24.2; P < 0.001). We then randomly separated patients into training and validation cohorts. Independent predictive factors of dengue infection were white blood cells < 4 × 109/L (score 1), platelets < 100 × 109/L (score 1), and MDW > 24 (score 1). Clinical features were not significantly predictive of dengue infection. The areas under the receiver operating characteristic curve (95% CI) of the prognostic score were 0.839 (0.779-0.899) in the training cohort and 0.742 (0.674-0.811) in the validation cohort. With a cutoff score ≥ 1, the sensitivity and specificity of the scores were 92.2% and 40.8% in the training cohort and 88.9% and 44.1% in the validation cohort, respectively. We concluded that MDW increases with dengue infection and MDW could easily be incorporated in the predictive scores for dengue infection.

Abstract Background Dengue infection is a differential diagnosis in patients with acute undifferentiated fever. Early detection and management may reduce mortality. Monocyte distribution width (MDW) is a new parameter in complete blood count (CBC). It is recently approved for early detection of sepsis. We have noticed high MDW in Dengue patients. This study aimed to describe MDW changes in Dengue infection and to develop predictive score for early detection of Dengue infected patients. Methods We retrospectively retrieved data of adult patients with acute fever who had CBC and Dengue serology (NS1 antigen, IgM and IgG) performed during September 2019 to May 2020 at Thammasat University Hospital. Medical records were reviewed. MDW was compared between groups. Patients were randomly divided into training and validation set. Predictive score was developed from the training set and validated in the validation set with multivariable analysis. Results A total of 431 patients, with Dengue infection in 127 patients (29.5%), were included in the analyses. The median (interquartile range) of MDW in Dengue patients were higher than non-Dengue patients [29.7% (26.5 – 34.7) vs. 24.2% (21.1 – 27.8), P < 0.001]. In patients with confirmed Dengue infection, MDW increased with increasing severity (Figure). Training and validation sets included 216 and 215 patients with 64 and 63 Dengue infection, respectively. Independent predictive factors of Dengue infection were white blood cell < 4 x 109 /L (score 1), platelet < 100 x 109 /L (score 1) and MDW > 24% (score 1). No clinical features were independently predictive of Dengue infection. The area under receiver-operating-characteristic curve (95% confidence interval) of the prognostic score in the training and validation set were 0.839 (0.779 – 0.899) and 0.742 (0.674 – 0.811), respectively. With the cut-off score ≥ 1, the sensitivity and specificity of the score were 92.2% and 40.8% in the training set and 88.9% and 44.1% in the validation set. Monocyte distribution width in Dengue and non-Dengue patients Box-plot showing monocyte distribution width in patients with Dengue in comparison with non-Dengue (panel A) and compared between each Dengue severity (panel B) Conclusion MDW increase in patients with Dengue infection and also increase with Dengue severity. We have developed and internally validated a simple predictive score for Dengue infection based on only results from CBC and MDW. Further large-scale external validation study is required to confirm the utility of our predictive score. Disclosures All Authors: No reported disclosures.

Background Secondary acute myeloid leukemia (sAML) and AML with myelodysplasia-related changes (AML-MRC) both result in dismal outcomes. This retrospective study aimed to determine whether these features are poor prognostic factors independent of older age and adverse cytogenetics, which are commonly associated with a poor prognosis. Methods The characteristics and real-world outcomes of sAML and AML-MRC from the Thai AML registry database were investigated. Results From a total of 992 newly diagnosed AML patients, 315 (31.8%) patients were classified into sAML or AML-MRC subtypes. Older age, low white blood cell (WBC) count, low bone marrow blast, and adverse cytogenetic risk were commonly present in sAML and AML-MRC compared to de novo AML. Complete remission after 7 + 3 induction therapy occurred in 42.3% of patients with sAML or AML-MRC and 62.4% of de novo AML (P < .001). The median overall survival (OS) of sAML, AML-MRC, and de novo AML were 6.9, 7.0, and 12.2 months, respectively (P < .001). The independent prognostic factors for inferior OS were older age, intermediate-risk or adverse-risk cytogenetics, WBC count > 100 × 109/L, poor performance status, and a subgroup of AML-MRC with the morphologic criteria of multilineage dysplasia (AML-MRC-M). In addition, sAML, AML-MRC, and a WBC count > 100 × 109/L were pre-treatment prognostic factors associated with poor relapse-free survival (P = .006, P = .017, and P < .001, respectively). Conclusion Both sAML and AML-MRC are independently associated with poor outcomes in Thai patients. Our study supports AML-MRC-M as an adverse prognostic factor for OS.

BACKGROUND:Intermediate or high doses of cytarabine (IDAC or HiDAC) were recommended as postremission chemotherapy for acute myeloid leukemia (AML). This retrospective study investigated the real-world outcomes of 3-different cytarabine doses from the multicenter Thai AML registry database. PATIENTS AND METHODS:The intermediate- and adverse-risk AML patients (N = 258) who achieved complete remission and proceeded to single-agent cytarabine consolidation were enrolled. RESULTS:The median relapse-free survival (RFS) using IDAC 1.5 g/m2, high-dose cytarabine (HiDAC) 2 g/m2, and HiDAC 3 g/m2 were 12.6, 11.7, and 13 months, respectively. The median overall survival (OS) using IDAC 1.5 g/m2, HiDAC 2 g/m2, and HiDAC 3 g/m2 were 34.9, 22.7, and 23.7 months, respectively. No significant difference in RFS and OS was detected between the 3 doses. Secondary AML, white blood cell > 100×109/L and the adverse-risk AML were independent prognostic factors for inferior survival (P= .008, P < .001, P= .014). Patients who completed 3 to 4 cycles of consolidation had significantly superior RFS and OS (P< .001, P< .001). Febrile neutropenia occurred in 72.9% of IDAC, 73.8% of HiDAC 2 g/m2, and 78.1% of HiDAC 3 g/m2 without statistical significance. However, the incidence of septic shock was significantly higher after HiDAC 3 g/m2 compared to IDAC regimen (8% vs. 3%, P= .037). CONCLUSION:IDAC is an appropriate regimen for postremission chemotherapy for intermediate- and adverse-risk AML. The higher dosing levels may not produce any benefits to patients and may increase incidence of septic shock. The number of consolidation cycles may impact on survivals rather than the intensity of cytarabine.

BACKGROUND:Diffuse large B-cell lymphoma (DLBCL) is the most common aggressive lymphoma. The standard first-line therapy for DLBCL consists of rituximab cyclophosphamide doxorubicin vincristine and prednisone (R-CHOP). About 50-70% of patients may be cured by R-CHOP. There was no data on external validation and comparison of the international prognostic index, revised-IPI (R-IPI), and enhanced-IPI (NCCN-IPI) to predict treatment outcomes in the middle-income country with a resourced-limited setting. OBJECTIVES:We aimed to externally validate and compare IPI, R-IPI, and NCCN-IPI in predicting 2-year progression-free survival (2-y PFS) of newly diagnosed DLBCL patients treated with R-CHOP. METHODS:This ambispective observational study recruited consecutive patients diagnosed between 1 January 2014 and 30 June 2020, with the last follow-up on 1 July 2022 from Thammasat University Hospital and Ramathibodi Hospital. We assessed discrimination by Harrell's concordance index (c-index), calibration by calibration plot, and absolute difference in survival (ADS) between the lowest-and the highest-risk groups. RESULTS:The cohort of 292 patients (median age 63 years and median follow-up 3.6 years) had 131 progressions and 96 deaths. The 2-y PFS was 63%. The c-indices were NCCN-IPI 0.6216, R-IPI 0.6004 (P = 0.215), and IPI 0.6104 (P = 0.463). The calibration plots of NCCN-IPI and R-IPI showed nearly perfect agreement (moderate strength), while IPI had miscalibrations. The ADSs were NCCN-IPI 52%, R-IPI 42%, and IPI 25%. CONCLUSION:NCCN-IPI is the best prognostic index compared to IPI and R-IPI in prior studies. However, the prognostic model for DLBCL patients treated with R-CHOP requires updating or integrating biomarkers to improve discrimination to the acceptable level (c-index 0.7).