A recent report published by Hamilton et al in The American Journal of Human Genetics looked at variations in the ERAP2 gene and their effect on respiratory infection and autoimmune diseases, including rheumatoid arthritis. Previous research has shown that people who survived infection with the bubonic plague were more likely to have variants in ERAP2 than those who died of it. In the current study, researchers found that patients with ERAP2 variants were not at an increased risk of rheumatoid arthritis, though other research has identified a relationship between ERAP2 and juvenile idiopathic arthritis. The study authors wrote, “Decreased ERAP2 expression is associated with severe respiratory infection with an opposing association with autoimmune diseases…. [I]ncreased expression of ERAP2 is protective for respiratory infection but increases the odds of some autoimmune diseases and [is] associated with reduced parental longevity. These results suggest ongoing balancing selection at this locus driven by autoimmune and infectious disease.”
May 25, 2023