IL17A and autoimmune disease: Carriage of E. gallinarum (n = 2 CVIDid, n = 2 CVIDio, n = 3 HC with E. gallinarum vs n = 26 CVIDid, n = 27 CVIDio, n = 27 HC without E. gallinarum) was associated with increased serum levels of IL-17A (p = 0.004, Fig. 7), a pro-inflammatory cytokine produced by T-cells that is strongly associated with autoimmune diseases.