Histocompatibility antigens in adult obliterative bronchiolitis with or without rheumatoid arthritis.

We compared HLA antigens in 28 patients with obliterative bronchiolitis (16 with rheumatoid arthritis) with those in 150 normal controls, to determine their relationship to drug toxicity and to the pathogenesis of obliterative bronchiolitis (OB). There was a significantly increased prevalence of HLA-B40 in the whole group and in patients with OB and rheumatoid arthritis (RA). There was increased frequency of HLA-A2 and A28 within the whole group and in those with OB alone. HLA-A3 and B5 were completely absent in our patients. Of those antigens most frequently associated with RA, DR4 was significantly more prevalent in patients with OB, with or without RA, but DR1 occurred more frequently only in those with RA-associated OB. Increased prevalence of DR4 may indicate an association between the pathogenesis of both OB and RA and the HLA-DR locus. Although D-penicillamine has been implicated in the pathogenesis of OB our patients did not show an increase in those antigens associated with other gold/penicillamine toxicity (i.e. DR2/3), suggesting that they may constitute a distinct group.