To investigate the frequency of HLA-DR and DQ antigens among patients with congenital dislocation of the hip joint or dysplastic osteoarthritis (OA) and to determine whether tissue typing might contribute to better understanding of these disorders.
HLA-DR and DQ typing was undertaken in 18 patients with congenital dislocation of the hip joints, 65 patients with dysplastic OA of the hip, 42 patients with primary OA of the knee, and 40 normal controls. Typing for HLA-D antigens was performed using the standard microlymphocytotoxicity method.
The frequency of HLA-DR4 in patients with congenital dislocation of the hip joint (61.1%) and patients with dysplastic OA of the hip (58.5%) was significantly increased compared with normal controls (27.5%) (Pcorr < 0.05 and P < 0.01, respectively). The relative risk for HLA-DR4 was 4.1428 and 3.7104, respectively, in these 2 disease groups. The frequency of HLA-DR4 in the patients with primary OA of the knee (35.7%) did not differ significantly from that in normal controls.
The results strongly indicate that development of congenital dislocation of the hip joint and progression of dysplastic OA of the hip are associated with genes of the HLA-D region.