K/BxN‐induced poly‐arthritis is exacerbated by infection with the intestinal helminth parasite Hymenolepis diminuta; possible involvement of complement and mast cells

Abstract

We examined the effect of Hymenolepis diminuta (H.D.) infection on a model of polyarthritis, to determine if helminth therapy modulates joint inflammation. BALB/c mice were untreated or infected with 10 H.D. cysticercoids. After 8 days, polyarthritis was induced and joint swelling was measured for 13 days. At necropsy, joints and serum were collected for analysis. K/BxN treatment induced swelling of all joints compared to vehicle treatment. Front paws and knees of H.D. infected mice were significantly more swollen than those of non‐infected K/BxN‐treated mice. This was accompanied by significant increases in serum complement C5a and mast cell protease‐1 in H.D. + K/BxN‐treated mice on day 2 compared to control and K/BxN‐only treated mice. Thus, exacerbated inflammation is paralleled by evidence of increased mast cell activation in H.D. + K/BxN treated mice. Mast cell activation is crucial in the K/BxN model and increased activation may underlie the exacerbation of disease by H.D.. Our data indicate that autoimmune pathways may be differentially sensitive to helminth therapy. Research was conducted with the support of Foreign Affairs and International Trade Canada and a CIHR operating grant.