Onset of autoimmune glomerulonephritis derived from the telomeric region of MRL-chromosome 1 is associated with the male sex hormone in mice.

Female B6.MRLc1(82-100) congenic mice develop more severe autoimmune glomerulonephritis (AGN) than males. We assessed the effects of gonadectomy on the pathogenesis of AGN in these mice. One-month-old male and female mice were divided into sham-operated group (SG) and gonadectomized group (GG), and the pathological changes were investigated at 8 months. SG females showed higher spleen and thymus weights, serum total IgG and autoantibody levels, glomerular damage scores and percent IgG- and CD3-positive glomeruli as compared with SG males. Gonadectomy showed more remarkable effects in males than in females. Spleen and thymus weights, urinary albumin excretion, glomerular damage scores, percent IgG- and CD3-positive glomeruli, and CD3-positive areas in the spleen were significantly higher in GG males than in SG males. CD3-positive cells were observed in both the thymic cortex and medulla in all animals except SG males. The expression ratio of active Fc gamma receptor (Fcgr) 3 to inhibitory Fcgr2b in the kidneys, which we have previously demonstrated to have a great impact on pathogenesis in B6.MRLc1(82-100), was significantly higher in GG males than in SG males. These results suggested that the differences in the pathogenesis of AGN are primarily because of the inhibitory roles of the male sex hormones.