HLA B27, sacro-iliitis and peripheral arthropathy in acute anterior uveitis.

Thirty-four consecutively admitted patients with acute anterior uveitis (AAU) were examined. The male to female ratio was 1.8:1. Twenty-two patients (67%) were HLA B27 positive. Twelve (36%) had radiographical sacro-iliitis; all were males and were HLA B27 positive. Three of them were asymptomatic. Eighteen patients (53%) had low back pain suggestive of sacro-iliitis, but this symptom was associated neither with radiographical sacro-iliitis nor with HLA B27. Radiographical sacro-iliitis and HLA B27 occurred together more frequently in males than in females. It was concluded that the association between AAU and signs of joint affection reflects the association seen in HLA B27 positive patients, while HLA B27 negative patients suffered from low back pain as well. HLA B27 positive patients with AAU should be remitted for radiographical examination of the sacro-iliac joints.