The association of HLA-DR4 antigen with juvenile chronic arthritis and slipped capital femoral epiphysis

Seventeen children who met the criteria for juvenile chronic arthritis (JCA) were reviewed. Throughout the study, the clinical examination, HLA phenotyping, and radiological assessment of the hips were performed by separate authors who were blinded to other data. At the end of the study, the results were also compared with 25 healthy, age- and sex-matched children. Six of the children with JCA also had radiological signs of slipped capital femoral epiphysis (SCFE; five with minimal slip pattern, one with moderate slip), and five of them had DR4 in their genotypes, in contrast to the remaining 11 patients who did not {p < 0.001). On the other hand, only 2 of 25 children in the control group had DR4 (p < 0.01). The difference was not significant when the patients without SCFE were compared with the control group (p = 1.0). The relative risk of cases with DR4 antigen for SCFE was 57.5, while it was below 1 for the other antigens. These results suggest that although DR4 is not specific for JCA, it is the common HLA antigen for those who have SCFE, and patients with JCA and HLA-DR4 antigen should be examined for evidence of SCFE, which was not reported before to exist with JCA.