Spondyloarthritis in India

Abstract

Spondyloarthritis (SpA) is a family of systemic inflammatory rheumatic diseases that have been extensively reported and studied from India over the last >4 decades. The epidemiological studies estimate the prevalence of SpA to be 7-9 per 10,000 persons. There are a number of studies describing the clinical features of the different subsets of SpA showing the presence of all the clinical subtypes of SpA. Long-term follow-up studies are also available showing the variable progression of these subtypes. HLA-B27 and its subtypes are reported from India; its frequency in the Indian population is ~6% but >90% in ankylosing spondylitis (AS) with decreasing frequencies in other subtypes of SpA. The association of B∗27:05 and B∗27:04 with AS and SpA family of diseases has been confirmed in several studies. There have been several publications related to the immunopathogenesis of SpA showing evidence of sensitization to antigen fragments of enterobacteria leading to the perturbations in the innate and acquired immune system causing the diseases. 'Slipped disc' and 'tuberculosis' are the two most common misdiagnoses made by nonrheumatologists. An important observation was a steady decrease in the male: female ratio from 16 to 18:1 reported in the 1980s and 1990s down to 3:1 in most recent reports. This is likely to be due to increasing awareness and recognition of female SpA. An important observation has been a significantly higher proportion of peripheral arthritis reported among Indian axial SpA (axSpA) patients. It could be due to environmental exposure causing reactive arthritis type of onset that evolves into clinically recognizable SpA over time. In recent years, the reports on nonradiographic and radiographic axSpA categories have also appeared with similarities to that reported from the Western countries. This category showed the lowest male:female ratio (1.2:1) indicative of a much higher proportion of females in the nonradiographic axSpA category. The specific features related to the management were the widespread use of sulfasalazine for axSpA and much less use of biologicals, most likely due to financial reasons, in India.