Relation between bilharzial arthropathy and histocompatibility leucocytic antigen B27

Fifty cases of active schistosomiasis divided into group I test group consists of twenty-five patients with arthropathy and group II control group consists of twenty-five patients without arthropathy, were subjected to clinical examination, indirected haemagglutination test (IHAT) for bilharziasis and plain X-ray on lumbosacral, sacroiliac and knee joints. HLA-B27 antigen typing was also done as a trial to find association between this antigen and the Egyptian cases of bilharzial arthropathy. Clinical examination of patients with arthropathy showed that the frequency of joint affection was knee joint 76%, shoulder joint 12% and hip, elbow and sacroiliac joints were equally 4% affected. Although the affected joints were tender and with limited movement, there were no hotness, deformities and morning stiffness. There was no effusion nor swelling except in one case of knee joint arthropathy. The results of the IHAT showed hundred percent positivity in all the patients without significant statistical difference between the test and the control groups (P greater than 0.05). X-ray on the sacroiliac, lumbosacral and knee joints showed no abnormalities in all the cases. The results of the HLA-B27 antigen typing showed that the frequency of this antigen in the test group was 16% and in the control group was 4%. The relation risk was 4.57 and the aetiological fraction was very small 0.12. However there was insignificant statistical difference between the test and the control groups (P greater than 0.05).