Immune response and autoimmune diseases: A matter of sex

Immune response differs between women and men at many levels. In general, females mount stronger in-nate and adaptive immune responses in comparison to males. In particular, women show more effective phagocy-tosis and antigen presentation, stronger production of inflammatory cytokines, higher absolute number of CD4+ T cells, higher levels of circulating antibodies, in comparison to men. Genetic, epigenetic, hormonal and environmental factors contribute to sex differences in immune response. The strong immune response in women, on one hand, ap-pears to be beneficial, leading to the reduction of pathogen load and accelerating pathogen clearance, but, on the oth-er hand, it can be detrimental by causing autoimmune or inflammatory diseases. Accordingly, most autoimmune diseases are more prevalent in women than in men and symp-toms, disease course and response to therapy may also differ between males and females. In this review, we discuss possible mechanisms for sex-specific differences in autoim-munity with a special focus on rheumatoid arthritis, Sjögren’s syndrome, primary biliary cirrhosis, antiphospholipid syn-drome, systemic sclerosis, multiple sclerosis and systemic lupus erythematosus.