Hydroxyapatite rheumatism and HLA markers.

HLA typing of 38 patients suffering from calcific periarthritis (hydroxyapatite rheumatism) showed an increased prevalence of HLA A2 (66 per cent) and HLA BW35 (34 per cent) vs 44 per cent and 19 per cent in 591 controls (p less than 0.01 and p less than 0.03 respectively). These preliminary results suggest a possible association between factors controlling susceptibility to the disease and some HLA markers. Larger series of patients and family studies are required to confirm this hypothesis.