Significance of human leukocyte antigen-B27 expression in cases of reactive arthritis: A study in rural central India

Abstract

Background: Reactive arthritis (RA), apart from presenting as an immune reaction to certain microorganisms, had also shown to have a genetic predisposition. Human leukocyte antigen (HLA-B27) is an allele of the HLA Class I molecules and its positivity in a person is shown to be a strong predictor of RA. The present study was aimed to study the significance of HLA-B27 positivity in clinical presentation and progress of RA in rural central India. Materials and Methods: One hundred rheumatoid arthritis factor seronegative patients of symptomatic RA were enrolled in the study. HLA-B27 was detected by flow cytometry method and patients were divided into two groups, each of 50 depending on HLA-B27 positivity and negativity as case and control groups. The patients were contacted on their follow-up visits and the clinical information and progress of the disease was assessed and correlated with HLA-B27 status. Results: About 74% in study group and 62% in control groups were males in RA (P = 0.001 and 0.0007, respectively). Study cases with HLA-B27 positivity showed many significant differences in their clinical presentation and disease severity and progression over the control cases (HLA-B27 negative). The mean duration of symptoms in the study group was 22.7 ± 31.26 and 12.98 ± 6.94 in control group. Severity of arthritic pain was more in study group as compared to control group (P = 0.0007). Study cases showed more axial skeletal involvement (P = 0.0002), enthesitis (P = 0.0001), and sacroiliac joint involvement (P = 0.0005). Clinical evaluation of back pain with different clinical tests in study cases showed more morning spinal stiffness (P = 0.0001), low Schober index (P = 0.001), higher lateral flexion (P = 0.0001), and lower chest expansion (P = 0.0001). The severity of disease in follow-up period increased significantly in 92% of patients in the study group despite initiation of clinical management of arthritis, while decreased in 60% of patients in the control group (P = 0.0001). Conclusion: HLA-B27-associated RA presents with significantly more severe primary disease and a rapid course of disease. Thus, HLA-B27 association should be done in all patients of RS and positive patients must be followed more rigorously to prevent many possible complications. To the best of our knowledge, this is the first study in central India to report the importance of HLA-B27 in patients of RA with regard to its management and prognosis.