Human leukocyte antigen genes may outweigh racial background when generating a specific immune response in sarcoidosis.

Presented is a sarcoidosis patient of African origin, who was adopted at an early age and grew up in Sweden. This patient displayed an immune response identical to that previously reported in human leukocyte antigen (HLA)-DR17 positive Caucasian sarcoidosis patients in Scandinavia, with T-cell receptor AV2S3+ T-cells accumulating in the lungs. HLA typing also established that she was DR17 positive, which is a rare HLA type for individuals of African origin. To the authors' knowledge, this specific immune response has not previously been reported in patients of African origin. Moreover, the clinical manifestations of sarcoidosis were similar to those known to be strongly linked to HLA-DR17 in Scandinavians, i.e. with Löfgren's syndrome. The case presented here suggests certain human leukocyte antigen genes to be strongly linked to specific immune responses that are identical irrespective of the racial background. If such an immune response were important for the subsequent clinical manifestations, this case would argue for the importance of human leukocyte antigen genes in the genetic predisposition to sarcoidosis.