Pathologic findings in Rag2–/– mice 13 days after they received 1 × 108, 5 × 107, or 1 × 107 anti-MPO splenocytes, anti-BSA splenocytes, or nonimmunized control splenocytes. The extent of glomerular crescent formation is expressed as the mean percent of glomeruli with crescents in each animal. The extent of glomerular necrosis is expressed as the mean percent of glomeruli with necrosis in each animal. The extent of glomerular endocapillary hypercellularity is expressed as the mean on a scale of 0 (none) to 4+ (severe). The extent of glomerular immunostaining for IgG is expressed as the mean on a scale of 0 (none) to 4+ (very intense). Normal Rag2–/– mice had no crescents, necrosis, endocapillary hypercellularity, or glomerular Ig staining (data not shown).