[Familial incidence of bird-breeder's lung and HLA (author's transl)].

The cases of two siblings affected with bird-breeder's lung are reported. The analysis of their HLA group demonstrated that both belonged to the haplotype HLA Bw15. The finding of a familial incidence of this type of alveolitis favors the presence of a genetic susceptibility for the disease. The same HLA group has been found in the rare families heretofore reported with bird-breeder's lung. Given that the pathogenesis of extrinsic allergic alveolitis has recently been linked to cellular immunity (T cells), and that the presence of a common HLA haplotype in patients suffering from bird-breeder's lung is related to the capacity for an immune response in general, and to the cellular immune response in particular, the presence of a genetic susceptibility in this disease appears as very likely, although the influence of other factors can not be ruled out.