Influence of HLA-B*5703 and HLA-B*1403 on susceptibility to spondyloarthropathies in the Zambian population.

OBJECTIVE

To analyze the distribution of HLA-B alleles and to investigate their contribution in the susceptibility to spondyloarthropathies (SpA) in a sample population from Zambia, in order to determine a relationship between some HLA-B alleles and development of ankylosing spondylitis (AS), reactive arthritis (ReA), or undifferentiated SpA (uSpA).

METHODS

. We selected 72 patients with SpA and found that 46 had uSpA, 23 ReA, and 3 AS. We also selected 92 matched controls; 55 of these had human immunodeficiency virus type I (HIV-I) infection.

RESULTS

We found a significant increase in the rate of uSpA and ReA with features of Reiter's syndrome (RS) in HIV-positive individuals who carried the HLA-B5703 allele (pc < 0.0001 and pc < 0.001, respectively). Among the significant new findings identified were the presence of B1403 in 2 of the 3 AS patients (pc < 0.05, OR 47), confirming previous data in the Togolese population.

CONCLUSION

The presence of B5703 and HIV infection may not affect susceptibility to AS and ReA, but they do show an important influence in uSpA and RS. Our findings confirm that HLA-B1403 is the only factor to increase the risk of AS in a sub-Saharan African population, whereas HLA-B27 was virtually absent in patients with AS.