Search Results (150)

Background: Type 1 diabetes mellitus (T1D) is associated with chronic inflammation, platelet-related alterations, and increased cardiovascular risk (CVR). The relationships between adipokines and platelet indices in long-standing T1D remain incompletely defined. Objective: To explore the relationships between adipokines (adiponectin and leptin), platelet indices, and inflammatory status in adults with long-standing T1D. Methods: This cross-sectional study included 124 adults with long-standing T1D and 59 non-diabetic controls. Platelet indices were obtained from automated blood count, and serum leptin (LEP), adiponectin (ADNC), and C-reactive protein (CRP) were measured using standardized assays. Associations were evaluated using correlation and multivariable regression analyses with adjustment for body mass index (BMI). Results: Platelet count (PLT) and plateletcrit (PCT) were higher in T1D compared with non-diabetic individuals (p = 0.003 for both), while mean platelet volume (MPV) and platelet distribution width (PDW) showed non-significant upward trends. ADNC levels were higher in T1D (p < 0.001), whereas LEP and the leptin–adiponectin ratio (LAR) did not differ between groups. In T1D, LEP correlated with PLT (rho = 0.235), PCT (rho = 0.263), and CRP (rho = 0.474), all p < 0.05. Similar associations were observed for LAR. No significant associations were found in non-diabetic controls. In multivariable analyses, PCT remained associated with LEP in T1D after adjustment for BMI, whereas in the control group, LEP was associated with BMI only. Conclusions: LEP and platelet-related indices were associated in individuals with long-standing T1D, whereas ADNC showed no such relationships. These findings suggest a distinct pattern of adipokine–platelet associations in long-standing T1D. Full article

Background/Objectives: In case of EDTA-induced pseudothrombocytopenia (PTCP), MgSO₄-anticoagulated tubes are recommended for platelet counting, requiring the collection of an additional tube. The aim of this study was to analyze whether complete blood count (CBC) and differential performed on MgSO₄-anticoagulated tubes were comparable to the results obtained on K₃-EDTA samples, and to characterize the stability of the CBC over a 24 h period. Methods: In 355 patients (70 with a confirmed PTCP and 285 without PTCP), we compared CBC results obtained on K₃-EDTA- and MgSO₄-anticoagulated tubes, using DxH800 analyzers. In 33 cases, a differential was available for both anticoagulants, and for 10 patients, samples were re-analyzed 6, 12, and 24 h after the first determination. Results: In the presence or absence of clumps, white blood cell (WBC) count, hematocrit, and mean corpuscular volume (MCV) were slightly lower in MgSO₄ than in K₃-EDTA tubes, whereas mean corpuscular hemoglobin concentration (MCHC) was slightly higher. Mean platelet volume (MPV) was significantly lower on MgSO₄- than on K₃-EDTA-anticoagulated tubes. Values were highly correlated between both anticoagulants, and mean relative biases (MRBs) were below Ricos’s recommendations, except for MCHC and MPV. For differential, neutrophils were significantly lower on MgSO₄- in comparison to K₃-EDTA-anticoagulated tubes (MRB = −2.9%, below Ricos’s optimal bias). The morphology of white blood cells (WBCs) was similar on both anticoagulants. During storage at room temperature, MCV and red cell distribution width increased slightly, but the increase was more pronounced in K₃-EDTA than in MgSO₄ tubes. Conclusions: CBC and differentials obtained with the DxH 800 analyzer on MgSO₄-anticoagulated samples are similar to those obtained with K₃-EDTA, except for MPV. Full article

Background/Objectives: Pulmonary embolism (PE) remains a major cause of mortality, requiring rapid risk stratification. Widely used clinical tools such as the simplified Pulmonary Embolism Severity Index (sPESI) may not fully capture the disease’s inflammatory burden. This study aimed to evaluate the prognostic value of multiple inflammatory indices and to develop a clinically applicable nomogram integrating these indices with sPESI for mortality prediction in acute PE. Methods: This multicenter retrospective cohort study included 338 patients with acute PE. Ten inflammatory indices were calculated from admission laboratory data. The primary outcome was 12-month all-cause mortality; secondary outcomes were 30-day and 90-day mortality. Receiver operating characteristic analysis, multivariable Cox regression, and person-time analysis were performed. A composite inflammatory risk score (0–10) was developed, and a nomogram combining this score with sPESI was constructed. Internal validation used 1000 bootstrap resamples. Results: Overall mortality was 44.1%, with 41% of deaths occurring in the first 12 months. The red cell distribution width-to-albumin ratio (RAR) showed the highest discriminative performance (AUC = 0.755, 95% CI: 0.704–0.806). Each 1-point increase in the inflammatory risk score was independently associated with increased 30-day mortality (HR: 1.21, 95% CI: 1.10–1.34) and 90-day mortality (HR: 1.25, 95% CI: 1.15–1.36). The nomogram improved risk classification, particularly in patients with intermediate sPESI scores (1–2). The combined model achieved an AUC of 0.806 (95% CI: 0.761–0.851), with good calibration (Hosmer–Lemeshow p = 0.342). Platelet-to-lymphocyte ratio (PLR) did not show significant prognostic value. Conclusions: RAR is a strong, independent predictor of mortality in acute PE, providing incremental prognostic value beyond sPESI. The integrated nomogram enables more precise risk stratification and offers a practical, low-cost tool for bedside use. Full article

Background: Hematological parameters derived from complete blood count (CBC) are inexpensive and widely available markers with potential utility in risk stratification of acute coronary syndrome (ACS). However, their incremental prognostic value when used alongside contemporary risk stratification tools such as the Troponin-only Manchester Acute Coronary Syndrome (T-MACS) score remains unclear. Methods: In this prospective, single-center cohort study, 521 patients presenting with non-ST-segment elevation myocardial infarction (NSTEMI) or unstable angina were enrolled. Admission CBC parameters (white blood cell count, neutrophils, monocytes, red cell distribution width, mean platelet volume) and derived inflammatory indices (neutrophil-to-lymphocyte ratio, white blood cell-to-mean platelet volume ratio, lymphocyte-to-monocyte ratio, mean platelet volume-to-platelet ratio, and red cell distribution width-to-platelet ratio) were recorded. T-MACS risk scores were calculated, and patients were followed for 30-day major adverse cardiac events (MACE), mortality, and coronary interventions. Associations were assessed using univariate and multivariate logistic regression analyses. Results: Patients experiencing 30-day MACE or mortality had significantly higher white blood cell counts, neutrophil counts, and WMR values (all p < 0.05). Several hematological indices showed significant associations with T-MACS risk categories. In multivariate analysis, intermediate- and high-risk T-MACS classifications independently predicted 30-day MACE (OR 4.49, 95% CI:1.46–13.77, p = 0.009; OR 9.34, 95% CI:3.00–29.03, p < 0.001, respectively), whereas white blood cell count, neutrophil count, and WMR did not demonstrate independent prognostic value beyond T-MACS classification. Conclusions: Admission white blood cell count, neutrophil count, and WMR are associated with short-term adverse outcomes and T-MACS risk severity in patients with NSTE-ACS. However, these markers do not provide additional prognostic value beyond T-MACS classification. These findings suggest that CBC-derived inflammatory markers primarily reflect disease severity rather than incremental prognostic information in the contemporary high-sensitivity troponin era. Full article

Background: Head trauma is a major public health concern. Computed tomography (CT) is frequently used to evaluate these patients but may expose them to unnecessary radiation exposure. Various biomarkers have been investigated to predict prognosis and reduce the need for unnecessary imaging. Red cell distribution width (RDW), neutrophil/lymphocyte ratio (NLR), and platelet/lymphocyte ratio (PLR) have been proposed as inflammatory markers; however, their diagnostic value in head trauma remains controversial. This study aimed to determine the value of complete blood count parameters in identifying intracranial injury in patients with mild head trauma. Methods: This prospective, single-center study enrolled 100 adults with mild head trauma. Demographic data, vital signs, neurological assessments, complete blood counts, CT results, and clinical outcomes were also recorded. Patients were categorized as intracranial injury positive (Group 1) or intracranial injury negative (Group 2). We statistically compared the laboratory and demographic data of the groups. Statistical significance was set at p < 0.05. Results: The study included 100 patients with mild head trauma who presented to the emergency department, of whom 11 were in Group 1. The median PLR and lymphocyte levels differed significantly between the groups (p < 0.05). Conclusions: The PLR may serve as a preliminary supportive marker to aid clinical assessment; however, its modest discriminatory performance suggests that it should not be used as a standalone diagnostic tool. Full article

Background: The study aimed to evaluate whether routine hematological parameters can differentiate attack and remission phases in children with Familial Mediterranean Fever (FMF) and to identify accessible biomarkers for disease activity monitoring. Methods: This retrospective study included pediatric FMF patients diagnosed according to Tel Hashomer, Livneh, or Yalçınkaya criteria at Aydın Adnan Menderes University between April 2000 and April 2020. Patients with complete blood count data available for both attack and remission phases were analyzed. Hematological parameters included leukocyte, neutrophil, lymphocyte, and platelet counts, plateletcrit (PCT), mean platelet volume (MPV), and platelet distribution width (PDW). Paired comparisons were performed using appropriate statistical tests. Independent predictors of disease phase were identified using a multivariate mixed-effects logistic regression model. Results: Eighty-seven patients (mean age at diagnosis 7.1 ± 3.6 years) were included. Neutrophil counts were significantly higher during attacks than remission (p < 0.001). Although lymphocyte counts were not significant in univariate analysis, higher lymphocyte concentration was independently associated with remission (OR = 1.71, 95% CI: 1.19–2.45). PDW was significantly higher during remission and independently predicted remission status (OR = 1.92, 95% CI: 1.30–2.85). PCT and MPV were not significant predictors. Conclusions: Neutrophil count, lymphocyte count, and PDW may represent potential and accessible markers associated with FMF attack and remission phases in pediatric patients. Full article

Background and Objectives: We aimed to determine whether preoperative systemic inflammatory markers derived from complete blood count differ between patients with intradural spinal tumors and healthy controls, and whether any such difference varies by pathological subtype or motor deficit status. Materials and Methods: Sixty-four patients who underwent surgery for histopathologically confirmed intradural spinal tumors between 2015 and 2023 were enrolled alongside 64 age- and sex-matched healthy controls. The neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), systemic immune-inflammation index (SII), pan-immune-inflammation value (PIV), and red cell distribution width (RDW) were calculated from preoperative complete blood count results. Comparisons were performed at the patient–control level and stratified by pathological diagnosis (meningioma, schwannoma, ependymoma, other) and motor deficit status. Results: NLR (median 2.47 vs. 2.06; p < 0.001), PLR (157.1 vs. 121.0; p < 0.001), SII (706.1 vs. 595.0; p = 0.003), and PIV (404.2 vs. 287.0; p < 0.001) were all significantly elevated in the tumor group, while LMR was significantly lower (3.66 vs. 4.34; p < 0.001). RDW did not differ between groups (p = 0.420). Stratification by pathological subgroup and motor deficit status revealed no significant differences in any marker. Conclusion: Intradural spinal tumors—including the predominantly benign cases that made up most of this cohort—are accompanied by a detectable preoperative shift in systemic inflammatory markers, one that appears independent of tumor histology and neurological presentation. These findings demonstrate a measurable systemic inflammatory response in patients with intradural spinal tumors. However, the absence of differences across pathological subtypes and motor deficit status suggests that these markers reflect a generalized host response rather than tumor-specific characteristics, and their role in clinical decision-making remains to be clarified. Full article

Cancer is a leading cause of death in humans and dogs. Several erythrocyte and platelet characteristics (indices and morphology) have shown promise as indicators of metastasis in humans. Similar studies have not been performed in dogs. This study evaluated erythrocyte and platelet characteristics measured on the Advia 2120i in 59 tumor-bearing dogs with carcinoma or sarcoma. Tumor-bearing dogs with and without intracavitary hemorrhage that underwent complete post-mortem and histopathology examinations were compared to healthy age-controlled dogs. Carcinoma- and sarcoma-bearing dogs without hemorrhage were compared. All tumor-bearing dogs without hemorrhage or metastasis were compared to those with metastasis, and characteristics were evaluated as indicators of metastasis. Tumor-bearing dogs without intracavitary hemorrhage (n = 49) had decreased hematocrit (p = 0.002) and reticulocyte hemoglobin content (p = 0.022), and increase in anisocytosis (p = 0.002), polychromasia (p = 0.002), macrocytosis (p = 0.032), codocytes (p = 0.022), absolute reticulocyte count (p = 0.035), platelet concentration (p = 0.002), plateletcrit (p = 0.022), and platelet volume distribution width (p = 0.022) compared to healthy dogs (n = 20). In tumor-bearing dogs with intracavitary hemorrhage (n = 10), additional significant differences were reflective of acute hemorrhage. No difference in characteristics between carcinoma- and sarcoma-bearing dogs without hemorrhage was identified. After correction for multiple comparisons, no differences in erythrocyte or platelet characteristics were identified between tumor-bearing dogs without intracavitary hemorrhage and metastasis and those without metastasis. Significant differences in characteristics exist between tumor-bearing dogs and healthy dogs. Based on the limited number of dogs in this preliminary study, no red blood cell or platelet characteristics were associated with metastatic disease in tumor-bearing dogs without hemorrhage. Full article

Background and Objectives: Residual coronary anatomical complexity following culprit-lesion-only percutaneous coronary intervention (PCI) remains a major determinant of clinical outcomes in patients with multivessel coronary artery disease (CAD). Platelet distribution width (PDW), a marker of platelet heterogeneity and activation, has been associated with adverse cardiovascular outcomes; however, its relationship with post-procedural residual disease burden remains unclear. This study aimed to evaluate the association between PDW and residual SYNTAX (Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery) score and to determine its incremental predictive value beyond established clinical variables. Materials and Methods: In this retrospective, single-center study, 140 patients with multivessel CAD undergoing culprit-lesion-only PCI followed by planned staged revascularization were included. Clinical presentation was categorized as chronic coronary syndrome (CCS), non-ST-elevation myocardial infarction (NSTEMI), or ST-elevation myocardial infarction (STEMI). Residual SYNTAX score was calculated after the index procedure, and patients were stratified into low (≤22) and high (≥23) groups. Associations between PDW and residual SYNTAX score were assessed using correlation and regression analyses. Model discrimination and incremental predictive value were evaluated using ROC analysis, hierarchical logistic regression, and reclassification metrics. Nonlinear relationships were explored using restricted cubic spline analysis, and clinical utility was assessed by decision curve analysis. Results: PDW was significantly correlated with residual SYNTAX score (Spearman ρ = 0.503, p < 0.001) and increased progressively across SYNTAX severity strata and clinical presentation groups. In multivariable analysis, PDW remained independently associated with high residual SYNTAX score (OR 1.38, 95% CI 1.07–1.82, p = 0.016). The addition of PDW to a hierarchical clinical model significantly improved model performance (ΔR² = 0.049, p = 0.012). Although the improvement in area under the curve (AUC) was modest, reclassification analyses demonstrated significant net reclassification and discrimination improvements. Spline analysis revealed a nonlinear relationship, with a marked increase in risk beyond PDW levels of approximately 13 fL. Decision curve analysis confirmed the clinical utility of PDW across a range of threshold probabilities. Conclusions: PDW is independently associated with post-procedural coronary anatomical complexity and provides incremental predictive value beyond established clinical variables. However, PDW should be interpreted as a biomarker reflecting platelet heterogeneity within a thromboinflammatory context, without the ability to distinguish between acute and chronic components. Full article

Objective: Cerebral cavernous malformations (CCMs) are usually occult but can present with a symptomatic hemorrhage. Treatment recommendations for CCMs are still controversially discussed, as all CCMs have signs of chronic hemorrhage. The distinction of acute hemorrhage can be difficult, especially when patients only present with mild symptoms. Because of emerging evidence supporting inflammatory burden as a main avenue in the disease pathogenesis of CCMs, the aim of the present study was to investigate routine inflammatory parameters to support decision-making in ambiguous cases. Methods: A total of 87 patients who underwent CCM resection at the authors’ institution between 2008 and 2021 were included in this study. Data were recorded retrospectively. Patients were dichotomized into two groups: those with acute hemorrhage and those without, as a control group (e.g., resection for seizure control). Inflammatory parameters included C-reactive Protein (CrP), White Blood Cell Count (WBC), Red Cell Distribution Width (RDW), and Mean Platelet Volume/Platelet Count Ratio (MPV/PC). Results: The receiver operating characteristic curve demonstrated moderate diagnostic accuracy for predicting acute hemorrhage from CCM based on WBC at admission (AUC: 0.74, 95%-CI: 0.63–0.84) with a cut-off of ≥6.595 G/L. The multivariable analysis confirmed that having a WBC > 6.595 G/L is an independent predictor for acute hemorrhage of CCM (adjusted odds ratio: 4.5, 95%-CI: 1.8–11.2, p < 0.001). Conclusions: A white blood cell count >6.595 G/L was significantly associated with acute hemorrhage in CCMs and appears to be a quick-to-use biomarker in controversial cases. Moreover, leukocytosis emphasizes the involvement of neuroinflammation in acute hemorrhage of CCM. Further investigations are needed to analyze the precise role of inflammation in CCM pathogenesis and its impact on treatment strategies. Full article

Objectives: To evaluate the association between fecal calprotectin (FC) levels and routinely available blood-based inflammatory indices measured during the same clinical episode in pediatric patients, as well as to assess the diagnostic performance of a novel composite parameter, the Gastrointestinal Inflammation Index (GII). Methods: This retrospective cross-sectional study included pediatric patients who underwent simultaneous testing for FC, complete blood count, C-reactive protein, and albumin between 2022 and 2025. Hematological inflammatory indices, including neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), red cell distribution width (RDW), platelet mass index (PMI), systemic immune-inflammation index (SII), and the newly developed GII, were calculated. Correlations between FC and inflammatory indices were analyzed. Receiver operating characteristic (ROC) curve analysis was performed to evaluate diagnostic performance, and multivariate logistic regression was used to identify independent predictors of FC positivity. Results: Elevated FC levels were significantly associated with higher C-reactive protein levels, lower albumin concentrations, and increased values of RDW, PMI, SII, and GII (all p < 0.001). GII scores increased progressively across FC categories. In ROC analysis, GII demonstrated the highest discriminatory ability for predicting FC positivity (AUC = 0.660), followed by SII and PMI. In multivariate logistic regression analysis, only NLR remained an independent predictor of FC positivity (OR = 0.65, 95% CI: 0.44–0.97; p = 0.033). Conclusions: Blood-based inflammatory indices show significant associations with fecal calprotectin levels in pediatric inflammatory bowel disease. The novel GII may reflect the integrated systemic inflammatory burden related to intestinal involvement, while NLR appears to be a robust and practical independent marker. These indices may serve as adjunctive, rapid, and cost-effective supportive tools in clinical decision-making, although their moderate diagnostic performance limits their use as standalone screening markers. Full article

Background/Objectives: This study aimed to compare hematological and inflammatory markers among patients with dry and wet age-related macular degeneration (AMD) and healthy controls, and to evaluate the influence of geographic atrophy (GA) in dry AMD and treatment response (TR) in wet AMD on these markers. Methods: The study included patients with dry AMD (n = 54), wet AMD (n = 53), and age- and sex-matched controls (n = 55). Hematological parameters, serum albumin, and systemic inflammatory indices, including neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), systemic immune–inflammation index (SII), systemic inflammation response index (SIRI), pan-immune–inflammation value (PIV), and hemoglobin, albumin, lymphocyte, and platelet index (HALP), were compared among the groups. Results: Age and sex distributions did not differ significantly between groups. Compared to controls, the wet AMD group had significantly higher neutrophil counts (p = 0.013), red cell distribution width (RDW) (p = 0.033), and inflammatory indices, including NLR, PLR, SII, SIRI, and PIV (all p < 0.01). HALP levels were significantly lower in wet AMD (p < 0.001). Dry AMD patients also had higher PLR (p = 0.045) and RDW (p = 0.005) than controls. When comparing wet and dry AMD groups directly, SIRI (p = 0.041) and PIV (p = 0.029) were significantly elevated in wet AMD, indicating stronger systemic inflammatory burden. In the dry AMD subgroup, patients with GA had significantly lower hemoglobin (p = 0.002) and erythrocyte counts (p = 0.039) than those without GA. No significant differences were observed between TR-positive and TR-negative wet AMD patients. Conclusions: Patients with wet AMD exhibit a more pronounced systemic inflammatory profile than both dry AMD patients and healthy controls. These findings support the hypothesis that systemic inflammation may contribute to AMD pathogenesis. Geographic atrophy in dry AMD may also be associated with additional hematologic alterations, whereas treatment response in wet AMD is not reflected in systemic markers. Full article

Background and Objectives: Accurate assessment of liver fibrosis is essential for treatment decisions in patients with chronic hepatitis B (CHB). Although liver biopsy is considered the reference standard, its invasive nature limits routine use. Serum-based non-invasive fibrosis scores have been proposed as alternatives; however, their diagnostic performance in CHB remains variable. This study aimed to compare multiple serum-based non-invasive fibrosis scores with liver biopsy findings and to evaluate their association with histological activity. Materials and Methods: This retrospective cross-sectional study included 219 adult patients with CHB who underwent liver biopsy with simultaneous laboratory evaluation. Patients with viral co-infections (HIV, HCV, or HDV), metabolic syndrome, diabetes mellitus, hepatic steatosis, or incomplete data were excluded. Non-invasive fibrosis scores—including APRI, FIB-4, AST/ALT ratio (AAR), age–platelet index (API), GGT-to-platelet ratio (GPR), Lok index, modified Forns index, Albumin–Bilirubin (ALBI) score, and red cell distribution width (RDW)-based indices—were calculated using routine laboratory parameters. Histopathological fibrosis staging served as the reference standard. Diagnostic performance was evaluated using receiver operating characteristic (ROC) curve analysis, and areas under the curve (AUC) were compared using the DeLong test. Associations with histological activity index (HAI) were assessed using Spearman correlation. Results: For the prediction of significant fibrosis (≥F2), FIB-4 demonstrated the highest AUC, followed by ALBI and APRI. For advanced fibrosis (≥F3), FIB-4 again showed the highest AUC, followed by APRI and GPR. For significant fibrosis (≥F2), DeLong analysis revealed no statistically significant differences between FIB-4 and the other serum-based scores (p > 0.05). APRI (r = 0.556, p < 0.001) and FIB-4 (r = 0.463, p < 0.001) showed the strongest correlations with HAI. In ROC analysis for moderate-to-severe histological activity (HAI ≥ 4), APRI demonstrated the highest diagnostic accuracy (AUC = 0.677). Conclusions: Serum-based non-invasive fibrosis scores demonstrate comparable but overall modest diagnostic performance for biopsy-confirmed fibrosis in patients with chronic hepatitis B. Indices such as FIB-4 and APRI demonstrated relatively better discrimination and may be considered as screening or rule-out tools in selected clinical contexts. APRI and FIB-4 also show associations with histological activity; however, their clinical application should be interpreted with caution, given their moderate discriminatory capacity. Full article

Background/Aim: This study aimed to evaluate the changes in hematological indices following methotrexate (MTX) initiation and assess their correlation with and predictive value for treatment responses in rheumatoid arthritis (RA) patients. Methods: A retrospective study was conducted on 299 DMARD-naïve RA patients who received MTX monotherapy for 12 weeks. Univariate and multivariate logistic regression identified predictors of remission and low disease activity. Correlation analyses assessed relationships between hematological and disease activity changes. Receiver operating characteristic (ROC) curve analysis evaluated the discriminatory ability of hematological parameters. Results: After 12 weeks of MTX, significant decreases were observed in white blood cell (p = 0.025), neutrophil (p = 0.026), hemoglobin (p = 0.001), and platelet counts (p < 0.001), alongside an increase in red cell distribution width (RDW) (p < 0.001). Multivariate analysis identified only baseline DAS28-CRP (OR: 9826.7, p < 0.001) and CRP (OR: 0.45, p = 0.005) as independent predictors for remission, and baseline swollen joint count, DAS28-CRP, and CRP for LDA. Hematological parameters were not independent predictors. ROC analysis revealed neither baseline values nor changes in hematological indices had satisfactory discriminatory power for remission or LDA. Conclusions: Hematological parameter changes do not serve as robust independent predictors for early treatment response. Clinical disease activity indices remain superior for prognostication in DMARD-naïve patients starting MTX. Full article

Background and Objectives: Reliable laboratory markers that accurately reflect disease activity in ankylosing spondylitis (AS) are limited. Conventional acute-phase reactants do not consistently correlate with clinical activity. Composite hematological indices derived from complete blood count may better capture systemic inflammatory burden. In this study, we aimed to investigate hematologic parameters in AS and to assess their relationships with disease activity. Materials and Methods: This retrospective observational study included 196 patients with AS. Disease activity was defined as a Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) ≥4. Demographic variables, laboratory parameters, hematological indices, and extra-articular manifestations were evaluated. Variable selection was performed using least absolute shrinkage and selection operator (LASSO) regression with ten-fold cross-validation. Variables with non-zero coefficients were entered into a multivariable logistic regression model. Model performance was assessed using receiver operating characteristic (ROC) curve analysis. Results: Ninety-seven (49%) patients had active disease. LASSO regression identified erythrocyte sedimentation rate (ESR), white blood cell count, red cell distribution width (RDW), platelet-to-lymphocyte ratio (PLR), and selected extra-articular manifestations as relevant predictors. In multivariable logistic regression, ESR (OR 1.03, 95% CI 1.00–1.06), white blood cell count (OR 1.23, 95% CI 1.04–1.46), and PLR (OR 1.01, 95% CI 1.003–1.020) were independently associated with active disease, while RDW showed a borderline association. The model demonstrated good discriminative ability (AUC 0.77, 95% CI 0.69–0.84). Conclusions: PLR is independently associated with disease activity in ankylosing spondylitis and improves discrimination when incorporated into a multivariable model. Easily accessible hematological indices may complement traditional inflammatory markers in the assessment of disease activity in routine clinical practice. Full article