Sarcoidosis-associated MHC Ags and the development of cutaneous and nodal granulomas following allogeneic hematopoietic cell transplant.

摘要

Sarcoidosis is a systemic chronic granulomatous disease involving the lungs, eyes and skin, often affecting young adults. Although of unknown etiology, sarcoidosis has been postulated to result from an immunological response to an environmental or antigenic trigger. Sarcoidosis has been associated with infectious and inflammatory conditions; however, the development of de novo sarcoidosis following allogeneic hematopoietic cell transplantation (alloHCT) has rarely been reported. A genetic predisposition to sarcoidosis is suggested due to familial clustering of cases and the increased prevalence in some ethnic groups. Sarcoidosis has been associated with specific gene products residing in the MHC.Specifically, the HLA class I Ags, Al and B8, and class II Ag, DR3, are present in higher frequencies in sarcoidosis patients. In addition, the class II alleles DRB 1*0301 and DQB 1*0201 (DQ2) are associated with acute sarcoidosis and a good prognosis, whereas DRBl*1501 and DQB 1*0602 have the opposite effect. We report a case of sarcoidosis following alloHCT in a patient with the Al, B8, DR3 and DQ2 haplotypes, as well as DRBl*1501 and DQB 1*0602. We postulate that immune dysregulation post alloHCT may promote sarcoidosis development in patients with susceptible HLA types (Al, B8 and DR3).