Intraduction The role of MEFV gene mutations in modifying disease course and treatment response in spondyloarthritis (SpA) remains unclear. We aimed to evaluate the the clinical and therapeutic implications of MEFV gene mutations. Methods A total of 131 SpA patients were categorized into MEFV negative (n=50), MEFV carrier (n=38), and Familial Mediterranean Fever (FMF) accompanying SpA (n=43) groups. Pathogenic variant carriers were further analyzed. Clinical features, disease activity scores, and treatment outcomes – including biologic DMARD use and response – were compared across the groups. Results The FMF accompanying SpA group had a significantly earlier disease onset (p=0.021) and higher amyloidosis frequency (p=0.040). Biologic usage rates were similar across groups (76% vs. 60.5% vs. 69.8%, p=0.295), as were anti-TNF response rates (80% vs. 77.3% vs. 78.6%, p=0.210). No significant differences were found when comparing pathogenic MEFV carriers with MEFV negative patients. Conclusion While MEFV mutations did not significantly alter classical disease activity measures or response rates to anti-TNF therapy in SpA patients, their presence, particularly in those with concomitant FMF, was associated with an increased risk of amyloidosis and a tendency toward a more complex inflammatory phenotype. Larger cohorts and prospective studies will clarify the impact of MEFV mutations on amyloidosis risk and treatments outcomes in SpA patients.

OBJECTIVES:Behçet's disease (BD) is characterized by relapsing mucocutaneous and major organ involvement. Although conventional immunosuppressants and CSs remain the mainstay of therapy, severe or refractory cases often require biologics. TNF-α inhibitors, particularly infliximab (IFX) and adalimumab (ADA), have become central to BD management. We compared the efficacy, safety, and drug retention of IFX and ADA in a real-world single-centre cohort. METHODS:Eighty-seven BD patients receiving IFX (n = 45) or ADA (n = 42) as their first anti-TNF therapy between April 2020 and 2025 were retrospectively reviewed. Baseline demographics, organ involvement, laboratory parameters, treatment regimens, and outcomes were recorded. RESULTS:Except for a tendency of male predominance in the IFX group, baseline demographics were comparable. Vascular (51.1% vs 26.2%) and neurological (15.6% vs 2.4%) involvement were more frequent in the IFX group, while ocular disease predominated in the ADA group (45.2% vs 28.9%). Complete remission was achieved in 75.6% (IFX) and 78.6% (ADA) initially, increasing to 88.9% and 76.5%, respectively, at the last visit. Concomitant AZA use exceeded 60% in both groups, while pulse glucocorticoids, CYC, and anticoagulants were more common with IFX. Relapses occurred more often and earlier with IFX (37.8% vs 16.7%, median 8 vs 13 months). Drug retention and adverse event rates were comparable (IFX 80% vs ADA 85.7%; ∼16% adverse events). No severe events occurred. CONCLUSION:Both IFX and ADA were highly effective and well tolerated in severe or refractory BD. ADA provided durable control in mucocutaneous and ocular phenotypes, whereas IFX offered rapid remission in vascular and neurological disease. Phenotype-oriented and individualized treatment strategies may optimize anti-TNF use in BD.

Objective: To evaluate treatment persistence, efficacy, and safety of rituximab (RTX) in patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV), with a specific focus on the impact of renal involvement. Methods: In this multicenter, retrospective cohort study, 214 AAV patients who received at least one RTX dose between 2012 and 2024 were analyzed. Patients were stratified based on renal involvement. The primary endpoint was RTX retention, defined as the time from the first infusion to permanent discontinuation for any cause. Secondary endpoints included remission, relapse, and infection-related discontinuations. Clinical characteristics, treatment indications (induction or maintenance), cumulative RTX doses, and safety outcomes were compared between renal and non-renal groups using descriptive statistics and survival analyses. Results: Among the cohort, 132 patients (61.7%) had renal involvement and 82 (38.3%) had non-renal involvement. The median RTX treatment duration was 24 months. RTX was used for maintenance in 72.4% of patients and for induction in 49% of patients. Drug retention did not differ significantly between renal and non-renal groups (log-rank p=0.608). Infections were the most frequent cause of RTX discontinuation (38.2% vs. 34.8%). Hypogammaglobulinemia occurred in 17.4% and 15.9% of patients, respectively (p=0.460). Mortality rates were comparable between groups (9.8% vs. 8.5%, p=0.475). Despite higher prior cyclophosphamide exposure in renal patients (12.1% vs. 3.7%, p=0.026), overall treatment outcomes were similar. Conclusion: RTX demonstrated sustained treatment persistence and an acceptable safety profile across AAV phenotypes, independent of renal involvement. These findings emphasize that RTX can serve as a phenotype-independent long-term therapeutic option, although vigilant infection monitoring remains crucial in all patients.

Background/aim:In Behçet's disease (BD), arterial involvement represents a significant clinical challenge associated with serious complications. The present study evaluates the characteristic features, affected vessels, lesion types, treatments, and outcomes in BD patients with nonpulmonary arterial involvement. Materials and methods:Included in this retrospective study were 65 BD patients whose interventions and clinical courses were accessed from medical records. The treatments administered included immunosuppressive (IS) therapies and surgical/endovascular procedures. Fisher's exact and t-test/Mann-Whitney U test were used for statistical analysis. Results:Fifty-nine of the patients (90.8%) were male. The median (Q1-Q3) follow-up was 4 (2-12.8) years. The most commonly affected vessels were the aorta (n = 21, 32.3%) and the femoral artery (n = 19, 29.2%). Aneurysm (n = 50, 63.2%) and thrombosis (n = 18, 22.7%) were the predominant lesions; 14 (21.5%) patients experienced arterial involvement while receiving IS therapy; and 11 (16.9%) had cardiac involvement. Cyclophosphamide and azathioprine were the most commonly used IS agents. Among the 39 (60%) patients who underwent surgical and/or interventional procedures, 32 (82%) had successful outcomes. A second arterial event was experienced by 15.3% of the sample during follow-up, and a third by 3%. Active disease was noted in nine (13.8%) patients at the time of their last visit, and of the six (9.2%) that died, most had both arterial and cardiac involvement. Conclusion:Arterial involvement in BD mostly presents with aneurysms, especially in men. Surgical interventions in addition to IS therapies are required in approximately 50% of cases. As can be understood from the 15.3% relapse rate in the present study, arterial events are not uncommon, underlining the need for long-term monitoring and sustained IS treatment. Of the 9.2% of cases who died, most had both arterial and cardiac involvement.

Patients with ANCA-associated vasculitis (AAV) are at increased risk of osteoporosis due to multiple disease- and treatment-related factors. However, real-world data on osteoporosis screening practices in this population remain limited. The aim of this study was to assess osteoporosis screening practices and the prevalence of reduced bone mineral density (BMD) in patients with AAV using a nationwide registry, and to identify factors associated with osteoporosis. This nationwide, retrospective, web-based study was conducted using the Turkish Vasculitis Study Group (TRVaS) database, including patients diagnosed with AAV between January 2000 and December 2023. Patients were evaluated for osteoporosis screening using dual-energy X-ray absorptiometry (DXA) and categorized according to BMD status. Clinical characteristics and potential risk factors were analyzed, and multivariable logistic regression was performed to identify independent predictors of osteoporosis. A total of 528 patients were included (median age 56 years [interquartile range 43–66]; 57.8

OBJECTIVES:To assess the effectiveness of canakinumab (CAN) in controlling clinical and laboratory inflammation by achieving complete control of cardinal disease manifestations and full normalization of laboratory inflammatory markers. METHODS:Data were obtained from the international AutoInflammatory Disease Alliance (AIDA) network registry, dedicated to monogenic autoinflammatory diseases. The assessment included both retrospective and prospective real-world data. RESULTS:In total, 158 FMF patients treated with CAN were enrolled. Complete clinical-laboratory response was observed in 45.6% of patients at 3 months, 58.6% at 12 months and 55.2% at the last follow-up, after a mean treatment duration of 45 months. Partial response occurred in 16.5%, 12.5% and 16.8% at the same timepoints, respectively. Complete absence of clinical manifestations was observed in more than 80% of patients at each timepoint. Inflammatory markers normalized significantly by the 3-month assessment. The probability of achieving and maintaining complete response and full laboratory control appeared higher in patients reaching these outcomes by 3 months, although it remained substantial in other patients as well. Complete response was associated with a relapsing-remitting disease course and fewer annual attacks. Nearly all patients maintained stable organ damage scores, and therapy discontinuation due to inefficacy was rare (≤6%). CONCLUSION:CAN is effective in achieving rapid and sustained clinical and laboratory control in FMF, including stringent endpoints of complete response. Early effectiveness may favour better long-term outcomes, but delayed achievement of complete response and full laboratory control is not uncommon. This study confirms CAN as an effective, and durable therapeutic option in FMF.

Eosinophilic granulomatosis with polyangiitis (EGPA) is a heterogeneous disease characterized by overlapping eosinophilic and vasculitic manifestations, and reliable markers reflecting disease phenotype and prognosis remain limited. In this study, we aimed to evaluate the clinical and prognostic significance of rheumatoid factor (RF) positivity in patients with EGPA and to explore phenotypic patterns using cluster analysis. Clinical features, laboratory findings, treatment and outcome data of 50 patients with EGPA from three tertiary referral centers were collected retrospectively and included in the study. RF positivity was defined as titers > 3× the upper limit of normal. RF positivity was observed in 36

Background: Mononeuritis multiplex (MM) is a severe and clinically heterogeneous form of peripheral neuropathy, most commonly arising in the context of systemic vasculitis in rheumatology practice. Despite its potential to cause substantial functional impairment, data on its clinical spectrum, management, and outcomes remain limited. Objectives: This study aimed to comprehensively evaluate the clinical characteristics, underlying etiologies, treatment approaches, and outcomes of MM in a nationwide multicenter rheumatology cohort. Design: Retrospective, multicenter observational study. Methods: Adult patients diagnosed with MM by rheumatologists across 27 tertiary referral centers were included. Data were collected using a standardized case report form, encompassing demographic features, clinical presentation, electrophysiological findings, laboratory parameters, treatment modalities, and outcomes. Neurological status was assessed at the final follow-up visit. Results: A total of 72 patients were analyzed (mean age 53.5 ± 14.9 years; 61.1% male). Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis was the most common underlying etiology (68%), with eosinophilic granulomatosis with polyangiitis being the predominant subtype. The typical clinical presentation consisted of acute-onset, asymmetric, distal involvement of the lower extremities, with foot drop as the most frequent manifestation (69.4%). Electrophysiological findings were consistent with a classical MM pattern in the majority of patients. Most patients received high-dose glucocorticoids combined with immunosuppressive therapy. Over a median follow-up of 29 months, 81.9% of patients achieved complete or partial neurological improvement. Outcomes were similar between ANCA-associated and non-ANCA-related diseases. Conclusion: MM represents a clinically diverse but potentially manageable neurological complication of rheumatic diseases. Early recognition supported by electrophysiological assessment, together with timely immunosuppressive treatment, may improve clinical outcomes. A multidisciplinary approach is essential to optimize long-term recovery and functional status.

OBJECTIVES:Salivary gland ultrasonography is a promising non-invasive modality for the evaluation of Sjögren's disease (SjD), but its diagnostic utility is limited by operator dependency. This study aimed to evaluate the classification performance of radiomics-based machine learning using parotid gland ultrasonography and to compare it with conventional visual assessment. METHODS:A total of 866 parotid gland ultrasound images from 202 participants were included: 123 patients fulfilling the 2016 ACR/EULAR criteria for SjD, 33 healthy controls, 24 non-Sjögren sicca patients, and 22 incomplete SjD cases. A total of 104 radiomic features describing intensity, texture, and micro-texture patterns were extracted. A 5-fold soft-voting SVM ensemble was trained on confirmed SjD and healthy participants; non-Sjögren sicca and incomplete SjD cases were reserved for the held-out test set. SHAP analysis was used for model interpretability. RESULTS:The SVM ensemble achieved an area under the receiver operating characteristic curve (AUC) of 0.99 for binary classification between SjD and healthy controls, with 0.94 accuracy, 0.86 sensitivity, and 0.96 specificity, outperforming radiologist assessments (accuracy: 0.62 and 0.72). SHAP analysis identified intensity dispersion metrics, GLCM-based texture features, and LBP micro-texture patterns as the strongest predictors. PCA and feature-level analyses demonstrated substantial overlap in radiomic features between non-Sjögren sicca and confirmed SjD patients. CONCLUSION:Radiomics-based machine learning demonstrated high classification performance for distinguishing SjD from healthy controls using parotid gland ultrasonography. Quantitative ultrasound analysis may serve as an objective adjunctive tool in SjD assessment, although validation in larger multicenter cohorts is required.

Pulmonary nodules are common in ANCA-associated vasculitis (AAV), but their clinical relevance remains unclear. This study assessed the influence of pulmonary nodules and radiological features on clinical characteristics and outcomes in AAV. In this multicenter retrospective cohort, clinical features and outcomes were compared between nodule-positive and nodule-negative AAV patients. Pulmonary nodules were classified as cavitary or non-cavitary, and their morphology and regression were evaluated on serial CT scans at diagnosis, 6 months, and last follow-up. Among patients with pulmonary nodules, radiological regression rates were compared according to cavitary and non-cavitary nodule status. Associations between radiological parameters, inflammatory markers, and radiological outcomes were evaluated using correlation analyses. Among 342 patients, 100 had pulmonary nodules at diagnosis (51 cavitary, 49 non-cavitary). Patients presenting with pulmonary nodules at diagnosis more likely to have lower baseline proteinuria, a higher prevalence of pleural effusion, and an increased risk of pulmonary nodule relapse (p = 0.043, p = 0.022, and p < 0.001, respectively). Radiological regression rates did not differ between cavitary and non-cavitary nodules at 6 months or last control. Moreover, smaller cavitary nodule diameter, a lower necrosis ratio, and fewer cavitary nodules were associated with a higher rate of complete radiological regression at 6 months (p = 0.016, p < 0.001, and p = 0.046, respectively). Larger cavitary nodule diameter and increased wall thickness correlated with elevated CRP levels (p = 0.001, r = 0.452 and p = 0.018, r = 0.340, respectively). In AAV, cavity size and wall thickness were associated with systemic inflammation. A lower necrosis ratio, smaller cavity diameter, and fewer cavitary nodules were associated with favorable radiological outcomes. These exploratory findings require prospective validation using standardized CT protocols. 1. Patients presenting with pulmonary nodules at diagnosis had a higher risk of pulmonary nodule relapse. 2. Larger cavity diameter and greater wall thickness were associated with higher systemic inflammatory activity. 3. A lower necrosis ratio, smaller cavity diameter, and fewer cavitary nodules were associated with complete radiological regression.

Background/Objective: Canakinumab (CAN), a monoclonal antibody targeting interleukin-1 beta, has demonstrated efficacy in various autoinflammatory diseases (AIDs), particularly in inadequate response to colchicine in familial Mediterranean fever (FMF). This study aimed to evaluate the indications, efficacy, and safety of CAN based on real-life experience from a tertiary rheumatology clinic.Methods: This single-center study included 54 patients treated with CAN between May 2020 and September 2024. Patients were grouped as MEFV-positive FMF (n=42), MEFV-negative FMF (n=7), non-FMF autoinflammatory diseases (n=2), and adult-onset Still's disease (AOSD; n=3). Demographic and clinical data, treatment indications, response patterns, laboratory parameters, and adverse events were analyzed.Results: CAN was initiated mainly due to adverse effects (40.5%) or inadequate response (42.8%) to anakinra and colchicine. The median duration of CAN therapy was 22 months. Among MEFV-positive FMF patients, 81% achieved a complete response and 19% partial response. CAN significantly reduced attack frequency and duration, and improved inflammatory markers (CRP, ESR, WBC, and neutrophil count). Proteinuria decreased in a statistically significant but clinically modest manner following CAN treatment. Only 1 patient experienced reversible cytopenia. Dose intervals were successfully prolonged in 54.8% of MEFV-positive patients without loss of efficacy.Conclusions: Canakinumab is an effective and well-tolerated IL-1 beta inhibitor in FMF and other AIDs, particularly in patients who are inadequately responsive or intolerant to colchicine and anakinra. Real-world experience supports its sustained efficacy and the feasibility of dose interval extension in selected cases.

Behçet's disease (BD) is a multisystemic inflammatory disorder that can affect vessels of all sizes, often leading to significant vascular morbidity. We present the case of a 37-year-old man with BD who developed a rare and severe postoperative complication involving vascular graft invasion into the duodenum. The patient initially underwent emergency aortobiiliac bypass surgery for a ruptured abdominal aortic aneurysm. Subsequent evaluation revealed clinical features consistent with BD, and immunosuppressive treatment with corticosteroids and azathioprine was initiated; however, adherence was interrupted due to repeated abdominal surgeries. On follow-up, he presented with lower-extremity ischemia and gastrointestinal bleeding. Imaging revealed a recurrent thrombotic event and, notably, a contrast-enhancing structure that raised suspicion of a vascular material. Endoscopic evaluation demonstrated vascular graft material protruding into the duodenal lumen with active bleeding. Urgent redo of aortobiiliac graft replacement and duodenal repair were performed. This complication was interpreted as a manifestation of an extended pathergy phenomenon, triggered by mechanical trauma from graft contact with the duodenum in the context of uncontrolled disease activity. Following postoperative stabilisation, intensified immunosuppressive therapy with azathioprine and infliximab was administered, thereby preventing further vascular events and other severe manifestations. This case underscores the critical importance of adequate immunosuppressive control before vascular surgery in BD to reduce severe postoperative complications.

Objectives To evaluate whether early canakinumab initiation may provide treatment advantages in Still’s disease (SD) patients, particularly in terms of therapy discontinuation due to long-term disease remission, glucocorticoid sparing effect, and increase in the frequency of monocyclic disease course rather than a polycyclic or chronic articular pattern. Methods SD patients treated with canakinumab were grouped according to time between disease onset and canakinumab initiation (≤3 months vs. >3 months). Patients were enrolled from the international AutoInflammatory Disease Alliance (AIDA) Network registry for SD. Results Overall, 190 patients were enrolled, 35 (19%) treated with canakinumab within three months from SD onset and 155 (82%) starting canakinumab later. Glucocorticoids use decreased more rapidly in patients receiving canakinumab within 3 months from SD onset than among patients treated later, with reductions of 50% vs 6% at month 3 (p=0.0001), and 75% vs 32% at month 6 (p=0.004). In logistic regression analysis, canakinumab initiation within 3 months from disease onset was significantly associated with treatment discontinuation due to long-term remission (OR 4.83, 95% CI 1.08-23.19; p=0.04). A monocyclic course occurred in 49% of patients starting canakinumab ≤3 months versus 8% starting later (p<0.0001). Starting canakinumab within 3 months from disease onset was significantly associated with a monocyclic disease course compared with the chronic-articular (RRR 4.43, 95% CI 1.12-17.60; p=0.034) and polycyclic courses (RRR 8.97, 95% CI 1.29-62.3; p=0.03). Conclusions Early canakinumab initiation is associated with treatment discontinuation due to long-term remission and appears linked to a greater frequency of a monocyclic disease course.

Tuberculosis (TB) remains a significant public health concern in endemic countries despite widespread Bacillus Calmette-Guérin vaccination. In rheumatology practice, biologic and targeted synthetic disease-modifying anti-rheumatic drugs (b/tsDMARDs) alter immune responses and increase the risk of reactivation of latent TB infection or development of new TB. Therefore, appropriate screening, treatment, and follow-up strategies before, during, and after initiation of advanced therapies are essential. These recommendations were developed by the Tuberculosis Working Group of the Turkish Society for Rheumatology through a systematic literature review, an evaluation of national and international guidelines, and a Delphi consensus process involving 12 experts. The recommendations address key clinical questions, including the definition of latent TB, the interpretation of the tuberculin skin test and the interferon-gamma release assay, the selection and duration of treatment regimens, management during pregnancy and lactation, the approach to patients with prior TB, and the management of TB occurring during advanced therapies. Isoniazid is recommended for nine months as the first-line treatment, with alternative options specified for particular clinical scenarios. The timing of advanced therapy initiation relative to latent TB treatment should be individualized based on disease activity and TB risk assessment. These recommendations aim to provide clinicians with a practical roadmap for latent and active TB screening and management in patients receiving b/tsDMARD treatments, and are consistent with national data.

Biostatistics and statistical literacy are essential competencies in postgraduate medical education, yet structured, clinically relevant training remains limited in many subspecialty settings. Evidence in postgraduate rheumatology biostatistics education is particularly scarce. This study evaluated the educational impact of a hands-on introductory biostatistics workshop delivered to rheumatology fellows using clinically contextualized examples relevant to rheumatology practice and research. This was a single-group pre-test/post-test quasi-experimental educational study with post-course evaluation and qualitative feedback analysis. The workshop was designed for rheumatology fellows and early-career rheumatologists and focused on clinically contextualized, applied biostatistics. Objective knowledge was assessed using a 15-item dichotomously scored test (score range 0–15), and self-efficacy was assessed using an 8-item Likert-type scale (score range 8–40). Matched pre–post changes in objective knowledge and self-efficacy were analyzed using the Wilcoxon signed-rank test. Course ratings were summarized descriptively, and open-ended responses were analyzed using descriptive content analysis. A total of 48 participants attended the workshop; 30 completed the pre-test, 41 completed the post-test, and 23 completed both assessments. Objective knowledge scores were significantly higher after the workshop, with the median increasing from 6.0 to 12.0 and the mean from 6.3 ± 3.5 to 10.0 ± 3.4 (p < 0.001; Z = -3.74; r = 0.82). Total self-efficacy scores were also significantly higher, with the median increasing from 14.0 to 31.0 and the mean from 18.4 ± 10.6 to 30.0 ± 8.0 (p < 0.001; Z = -4.11; r = 0.88). Post-course evaluations were favorable, with the highest ratings for preference for practical training (mean 4.5 ± 0.9) and overall satisfaction (mean 4.3 ± 1.1). Qualitative feedback emphasized hands-on learning, interactive teaching, instructor support, the need for more practice, and interest in advanced follow-up content. This hands-on, clinically contextualized introductory biostatistics workshop was well received and associated with significant short-term improvements in objective knowledge and statistical self-efficacy, suggesting that this approach may be feasible and acceptable as an entry point for postgraduate rheumatology biostatistics training. Further controlled and longitudinal studies are needed to determine durability, transfer to practice, and broader generalizability. 1. A Hands-on, clinically contextualized workshop was associated with short-term gains in knowledge and self-efficacy. 2. Learners strongly valued practical, interactive, and clinically contextualized teaching. 3. Future curricula should incorporate longitudinal follow-up and reinforcement sessions to support retention of biostatistical competencies.

OBJECTIVES:Behçet's disease (BD) is a multisystem inflammatory disorder with diverse phenotypes and incompletely defined immune mechanisms. This study aimed to map immune dysregulation in BD at high resolution, comparing active vs remission states and identifying pathways linked to clinical phenotypes. METHODS:We performed single-cell RNA sequencing on 247,028 peripheral blood mononuclear cells from 34 patients with BD and 12 healthy controls. Transcriptomic profiling, differential gene expression, pathway enrichment analyses, and phenotype-stratified comparisons were used to delineate immune cell alterations associated with disease activity and clinical subtypes. RESULTS:All 3 monocyte subsets were markedly expanded in BD and demonstrated dominant interferon (IFN)-γ-associated activation, robust heat-shock responses, and enhanced antigen-presentation programmes. In active disease, monocytes exhibited pronounced type II IFN signatures, which reversed in remission alongside restoration of regulatory and metabolic pathways. Remission was instead characterised by increased expression of type I IFN-regulated genes and activation of serine protease inhibitor (SERPIN)-associated programmes linked to tissue stabilisation. Clinical phenotype stratification revealed distinct transcriptional signatures in peripheral blood monocytes, including enrichment of heat-shock and stress-response pathways in monocytes from patients with vascular BD and tumour necrosis factor/NF-κB-associated programmes in monocytes from patients with ocular BD. Patients without organ involvement demonstrated an increased type I IFN gene signature. CONCLUSIONS:This study provides a high-resolution immune atlas of BD, identifying monocyte-driven dysregulation as a central feature. Our findings map the immune heterogeneity of BD, identify activity- and phenotype-linked peripheral blood monocyte states, and suggest immune pathways suitable for targeted intervention.

OBJECTIVES:Still's disease (SD) is an autoinflammatory disease (AID) that can lead to life-threatening macrophage activation syndrome (MAS). The role of procalcitonin (PCT) in AIDs remains unclear. This study aims to explore the relationship between non-infectious PCT elevation and clinical features of SD. METHODS:This retrospective study included patients with SD and absence of infection who had available PCT data. Control groups consisted of patients with confirmed bloodstream infections and age- and sex-matched healthy controls (HCs). A PCT cut-off of 0.5 ng/ml was used. Clinical and laboratory findings were evaluated based on baseline (PCT < 0.5 and PCT ≥ 0.5 groups) and maximum (PCTmax < 0.5 and PCTmax ≥ 0.5 groups) values. RESULTS:The study conducted with 110 patients with SD. Of these, 75 (68%) were in the PCT < 0.5 group and 35 (32%) were in the PCT ≥ 0.5 group, while 63 (57.3%) were in the PCTmax < 0.5 group and 47 (42.7%) were in the PCTmax ≥ 0.5 group. PCT levels were significantly higher in patients with SD compared with HCs and were nearly as elevated in MAS cases as in infection. Frequency of MAS, higher mPouchot scores and increased use of biologic DMARDs, particularly anakinra, were associated with elevated PCT. MAS risk increased 6.4-fold in the PCT ≥ 0.5 group and 7.6-fold in the PCTmax ≥ 0.5 group in univariate analysis, and 4.3-fold and 5.4-fold, respectively, in multivariate analysis. CONCLUSION:PCT may be a potential marker in AIDs such as SD, even in the absence of infection. Elevated PCT levels may serve as an independent predictor of MAS in SD.

Background/Objectives: Early identification of vasculitic acute kidney injury (AKI) is crucial for timely immunosuppression and improved renal outcomes; however, noninvasive adjunctive diagnostic tools remain limited. Renal elastography, a noninvasive technique that quantifies renal cortical stiffness, has been primarily investigated in chronic kidney disease, whereas evidence in acute kidney injury is scarce. This study aimed to evaluate the diagnostic utility of renal shear wave elastography for differentiating vasculitic from non-vasculitic AKI and to explore the association between baseline renal cortical stiffness and vasculitic renal outcomes. Materials and Methods: This prospective observational study included three groups: vasculitic AKI, non-vasculitic AKI, and healthy controls. Renal cortical stiffness was measured at admission using two-dimensional shear-wave elastography (2D-SWE) by radiologists blinded to clinical information. After clinicopathological confirmation of definitive diagnoses, between-group comparisons were performed and the diagnostic performance of elastography was evaluated. Additionally, in a biopsy-confirmed immunoglobulin A vasculitis nephritis (IgAVN) cohort (n = 12), baseline elastography measurements were examined in relation to one-year renal outcomes to explore potential prognostic associations. Results: The vasculitic AKI group exhibited significantly higher mean renal cortical stiffness values (9.5 ± 1.9 kPa) compared with both healthy controls (5.53 ± 0.92 kPa) and the non-vasculitic AKI group (6.61 ± 1.89 kPa) (both p < 0.01). Mean renal cortical stiffness demonstrated good diagnostic performance for distinguishing vasculitic from non-vasculitic AKI (AUC 0.86, 95% CI 0.73-0.97), with an optimal threshold of 6.79 kPa yielding 91% sensitivity and 72% specificity. In the prospective one-year follow-up of the IgAVN subcohort (n = 12), patients with unfavorable renal outcomes tended to have higher baseline renal cortical stiffness compared with those with favorable outcomes [median (min-max), 11.2 (10.8-13.3) vs. 9.1 (5.6-11.2), p = 0.046]. Conclusions: These findings suggest that renal elastography may aid in distinguishing vasculitic from non-vasculitic acute kidney injury and may provide exploratory information on the relationship between baseline cortical stiffness and renal outcomes in IgAVN.