Comparison of Platelet Indices and Erythrocyte Sedimentation Rate in Spinal Tuberculosis and Non-tuberculous Spondylitis: A Cross-sectional Study

Introduction: Spinal Tuberculosis (TB), also known as Pott’s spine, remains a significant cause of morbidity and often mimics non-infective spinal disorders both clinically and radiologically. Consequently, diagnosis of spinal TB is challenging owing to its non-specific clinical presentation and radiological overlap with other infective and non-infective spinal disorders. Aim: The present study aimed to evaluate and compare haematological parameters particularly Erythrocyte Sedimentation Rate (ESR) and platelet indices in tuberculous and nontuberculous spondylitis to assess their diagnostic utility. Materials and Methods: The present cross-sectional comparative study was conducted for a period of one year, from May 2024 to April 2025, at a tertiary care hospital, in the Departments of Pathology and Orthopaedics. A total of 64 patients aged ≥18 years were included: 33 patients with tuberculous spondylitis (diagnosed by acid-fast bacilli staining, culture, Polymerase Chain Reaction (PCR), histopathology, or clinico-radiological features) and 31 patients with noninfective spinal pathologies (such as degenerative disorders, scoliosis, and tumours). Haematological parameters including Haemoglobin (Hb), Total Leukocyte Count (TLC), ESR, platelet count, Mean Platelet Volume (MPV), Plateletcrit (PCT), Platelet Distribution Width (PDW), and Platelet Large Cell Ratio (P-LCR) were analysed using automated analysers (Sysmex XN-1500 for complete blood count and Alifax Test-1 for ESR). Statistical analysis was performed using Statistical Package for Social Sciences (SPSS) version 23. Group comparisons were carried out using the independent t-test or Mann-Whitney U test, and correlations were assessed using Pearson or Spearman correlation coefficients. A p-value <0.05 was considered statistically significant. Results: Patients with spinal TB had higher ESR (22.4±14.3 vs 20.9±20.1 mm/hr), MPV (12.0 vs 11.7 fL), PDW (15.9 vs 15.3 fL), and P-LCR (40.2 vs 37.4), and lower Hb levels (11.5 vs 12.3 g/ dL) compared with non-TB cases; however, these differences were not statistically significant (all p>0.05). ESR showed a weak negative correlation with Hb (r=-0.300, p=0.090) and negligible correlations with platelet count (r=0.044), PDW (r=- 0.123), MPV (r=-0.135), P-LCR (r=-0.070), and PCT (r=0.026), all with p>0.05. Conclusion: Although elevated ESR and mild haematological alterations are commonly observed in spinal TB, they lack sufficient specificity to reliably distinguish tuberculous spondylitis from non-tuberculous spinal conditions. Platelet indices also demonstrated limited diagnostic relevance. These parameters should therefore be used only as supportive tools within a comprehensive diagnostic framework that includes clinical evaluation, imaging, and microbiological investigations.