Occurrence of HLA-B27 tissue antigen in patients with purulent arthritis caused by Staphylococcus aureus or beta-haemolytic streptococci.

The HLA-B27 tissue antigen is associated with reactive arthritis caused by different bacterial infections but its occurrence in purulent arthritis has not been studied earlier. We analysed the frequency of HLA-B27 in patients with culture proven purulent arthritis caused by Staphylococcus aureus or beta-haemolytic streptococci. The study included 41 patients treated during the years 1979-96 (15 female and 26 male) with a mean age of 52 years (range 16-80 years). HLA-B27 was found in 24% (9/37) of the tested patients compared with 14% in the healthy Finnish population, but the difference was not statistically significant (P < 0.50). No statistical difference in disease activity according to febrile days or duration of the disease could be found between HLA-B27 positive and negative patients. We conclude that HLA-B27 is not a risk factor for purulent arthritis, and when present it has no significant modifying effect on the clinical picture of purulent arthritis.