HLA-B27 and its role in the pathogenesis of psoriatic arthritis

Abstract

The literature review presents the characteristics of the human leukocyte antigen (HLA)-B27 as a factor contributing to the development of psoriatic arthritis. HLA-B27 is a class I surface antigen encoded by the major histocompatibility complex (MHC) B locus located on chromosome 6. The main function is to present antigenic peptides to the CD8+ T-cells. HLA-B27 is the most important genetic biomarker for psoriatic arthritis, as it provides phenotypic differentiation in the patient population. The prevalence of HLA-B*27 in various population groups are presented. The structural features of the HLA-B27 molecule are described. The characteristics of methods for detecting HLA-B*27 status and determining its subtypes are given. The main mechanisms of the HLA-B*27 polymorphism influence on the development of psoriatic arthritis are considered, and hypotheses are analyzed that explain the pathogenic effect of HLA-B*27: the arthritogenic peptide hypothesis, the misfolding hypothesis, the HLA-B27 heavy chain homodimer formation hypothesis. The features of the clinical manifestations and course of HLA-B*27-positive psoriatic arthritis are presented, allowing the use of HLA-B27 to predict the development of psoriatic joint damage.