Complement activation was attenuated and kidney function improved in the absence of AID. (A) Glomeruli scores were compared between 12-week-old BXSB (n=12), 12-week-old BXSB.Aicda−/− (n=16) and 41-week-old BXSB.Aicda−/− (n=12) mice. (B-E) Kidney images from 12-week-old BXSB (n=5) and BXSB.Aicda−/− (n=5) mice. Ig (Green), C3c (Green) and DAPI (Blue). Images were evaluated for mean intensity in B and D. Representative Ig staining images were shown in C and C3c staining was shown in E (magnification 400X). Statistical significance was determined by Mann-Whitney U test. *p<0.05, **p<0.01. (F,G) Free catch urine samples were collected from 6-week-old and 16-week-old BXSB (n=8) and BXSB.Aicda−/− (n=6) mice. Albuminuria is shown in (F) and the albumin to creatinine ratio (ACR) is shown in (G). Statistical significance was determined by Two-way ANOVA. *p<0.05, **p<0.01.