HLA-B27 positivity and associated factors in spondyloartritis patients from Turkey: a single-center study

Aims: Spondyloarthropathies (SpA) constitute a category of multisystemic inflammatory seronegative arthritis. A genetic correlation exists between SpA and the human leukocyte antigen (HLA)-B27 gene. HLA-B27 positive is observed in roughly 90% of patients with ankylosing spondylitis. This study seeks to ascertain the prevalence of HLA-B27 positivity and its associated factors in SpA patients within the Turkish population, while also comparing the demographic, clinical, and radiological characteristics between HLA-B27 positive and negative groups, their utilization of bDMARDs, and the baseline and post treatment disease activity metrics. Methods: The study comprised 300 patients having accessible HLA-B27 findings. SpA patients were classified into two groups according to their HLA-B27 status: positive and negative. Demographic parameters, HLA-B27 results, disease activity scores, and the existence of radiographic abnormalities were documented in both groups. Results: Of the 300 patients involved in the study, 224 (74.7%) tested positive for HLA-B27. The median age of all patients was 45 years, with HLA-B27 positive individuals being younger. The median age for symptom start was 35 years, while the median age for diagnosis was 39 years. Analysis of the radiographic features based on ASAS criteria indicated that the radiographic axial SpA group comprised the largest proportion of patients at 69.2%, followed by non-radiographic axial SpA at 23.4%, and peripheral SpA at 7.4%. Upon comparison of the two groups, the seropositive cohort exhibited a markedly elevated prevalence of familial history. Hypertension was the predominant comorbidity in both the HLA-B27 positive and negative cohorts. The prevalence of smokers was markedly greater in the HLA-B27 positive cohort. The frequencies of radiographic sacroiliitis, syndesmophytes, bamboo spine, and hip involvement were elevated in the positive group when compared. Uveitis exhibited greater prevalence in the positive cohort. Upon comparison of the two groups, the post-treatment reductions in BASDAI, BASFI, VAS Pain, ESR, and CRP levels were more pronounced in the positive group than in the negative group. In comparing the HLA-B27 positive and negative cohorts, no significant disparities were observed in the frequency of single or multiple treatment modifications. Nevertheless, the alteration of bDMARD treatment was less common in the HLA-B27 positive cohort than in the negative cohort. Conclusion: HLA-B27-positive patients were younger, mostly male, experienced an earlier onset of disease, and demonstrated a more active disease progression. The treatment response was superior in the positive group relative to the negative group.