Human Leukocyte Antigen B27 (HLA-B27) and Its Association with Spondyloarthritis: Clinical Implications from a Tertiary Healthcare Center in Bangladesh

Abstract

Background: Spondyloarthritis (SpA) comprises a group of inflammatory rheumatic diseases characterized by axial and peripheral joint involvement and a strong association with the Human Leukocyte Antigen B27 (HLA-B27). Despite global recognition of HLA-B27 as a key genetic marker in SpA, data regarding its prevalence and clinical relevance in the Bangladeshi population remains limited. Aim: This study aimed to determine the frequency of HLA-B27 among patients with SpA in Bangladesh and to evaluate its association with clinical features, disease severity, and inflammatory markers. Methods: A cross-sectional observational study was conducted at a tertiary healthcare center in Dhaka, Bangladesh, from January 2023 to December 2023. A total of 180 patients diagnosed with SpA based on ASAS criteria were enrolled. Clinical data, including symptoms, SpA subtype, and extra-articular manifestations, were recorded. Laboratory tests for HLA-B27 (using RT-PCR), C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) were performed. Statistical analysis was conducted to assess associations between HLA-B27 status and disease characteristics. Results: Out of 180 patients diagnosed with spondyloarthritis, 120 (66.7%) were HLA-B27 positive. The highest rate of HLA-B27 positivity was seen in patients with Ankylosing Spondylitis (85%), followed by Psoriatic Arthritis (70%), Reactive Arthritis (65%), and Undifferentiated SpA (60%). HLA-B27-positive patients had a longer mean disease duration (6.8 ± 3.9 years) compared to those who were HLA-B27-negative (4.5 ± 2.1 years). Clinically, HLA-B27-positive individuals experienced significantly higher rates of inflammatory back pain (95% vs. 80%), morning stiffness (92% vs. 75%), peripheral joint involvement (64% vs. 48%), and sacroiliitis (78% vs. 53%). Extra-articular manifestations such as uveitis (18% vs. 7%) and psoriasis (24% vs. 12%) were also more common in the HLA-B27-positive group. Inflammatory markers were markedly elevated, with mean ESR and CRP levels significantly higher in HLA-B27-positive patients (38.0 mm/hr and 18.5 mg/L, respectively) than in HLA-B27-negative patients (27.0 mm/hr and 12.4 mg/L; p < 0.05 for both). These findings suggest that HLA-B27 is strongly associated with more severe disease features and increased inflammatory activity. Conclusion: The prevalence of HLA-B27 is notably high among Bangladeshi SpA patients and is strongly associated with more severe clinical presentations and higher inflammatory activity. HLA-B27 testing is a valuable diagnostic and prognostic tool, particularly in seronegative cases, and should be integrated into routine clinical practice to improve early diagnosis and personalized treatment strategies.