Allergic interstitial nephritis: report of a case with activation of complement by the alternate pathway.

An eighteen year old woman developed a streptococcal pharyngitis documented by throat culture. After two days of treatment with penicillin she developed arthritis and abdominal pain and within a week became anuric. Her renal biopsy revealed extensive interstitial nephritis without proliferative glomerular changes. Serum properdin levels were significantly reduced and immunofluorescence studies demonstrated properdin deposition within the glomeruli, C1, C4 and C2 were not depressed nor were they demonstrable within the glomeruli. These results support activation of complement apparently only by the alternate pathway, a finding heretofore noted only in membranoproliferative glomerulonephritis.