Seronegative spondarthritis and human leucocyte antigen association

The human leucocyte antigen (HLA) B27 has been associated with seronegative spondarthritis universally, but the associations varies (19-94%) in different Indian population groups. It is possible that this variation is due to patient selection bias. Here, we use strict clinical, radiological and serological criteria to select 79 patients with seronegative spondarthritis (SSA) and compare them with 110 healthy, normal individuals from the same ethnic background. The standard National Institute of Health (NIH) microlymphocytotoxicity assay is used to evaluate HLA B27 status in both groups. Significant association between HLA B27 and AS disease was found (odds ratio [OR]: 72.22; P<0.0001; confidence interval [CI]=1.5-3.8) when compared to the control group. Furthermore, HLA B5 was decreased when compared to the control group (OR: 0.39; P<0.01). Those in the 20-40 age group were more vulnerable, with a male preponderance (7:1) over females. These findings confirm the strong association of the HLA B27 allele with various types of spondarthritis and suggest that allele detection would help in the diagnosis of AS where clinical presentation is unclear and in identifying family members at risk.