Sarcoidosis and Autoimmunity: Evidence of Differential Associations with HLA Class II Markers

Ahigh frequency of endocrine autoim munity and gastrointestinal immune reactivity has been reported in sarcoidosis. The aim of the present study was to determine the immunogenetic background of sarcoidosis focusing on the associated autoim- mune manifestations. Materials and Methods: A total of 66 (38 males, 28 females) and /65 (37 males, 28 females) Cauca- sian patients with documented sarcoidosis diag- nosed at the Department of Pulmonary Medi- cine, Malmö University Hospital were genomi- cally typed for DRB1/DQB1. Results: The frequencies of HLA-DRB1*02 (p=0.004), DRB1*14 (p=0.022), DQB1*0602 (p=0.027), DQB1*0503 (p=0.022), were signifi- cantly increased in the whole group of patients with sarcoidosis as well as in sarcoidosis associ- ated with autoimmune manifestations compared to healthy controls. Conclusions: Significant associations of HLA- DRB1*02 and *14 and DQB1*0602 and *0503 with sarcoidosis were found, particularly apparent in the subgroup with associated autoimmune mani- festations. Different immunogenetic profiles may thus exist in sarcoidosis indicative and/or causative of distinct clinical subgroups. HLA class II presentation of a putative sarcoidosis- specific antigen might be of vital importance in sarcoidosis, deciding the direction of the sarcoid disease and eventual associations with it. Whether the above mentioned HLA class II hap- lotypes and/or their linked genes, alone or in unison with HLA class I, are organ- or disease- specific remains to be determined.