Persistent histological and immunological abnormalities in congenital syphilitic glomerulonephritis after disappearance of proteinuria.

A 40-day-old male infant suffered from generalized anasarca, proteinuria and hematuria. Serologic study revealed marked elevation of antibody titer against Treponema pallidum, the same serologic finding was also noted in both his parents. Two weeks of treatment with penicillin was given. The edema subsided 7 days later, and proteinuria and hematuria disappeared 20 days after the initiation of penicillin treatment. At the age of 60 days, all the clinical symptoms and signs vanished; urinalysis and renal function were all within normal limits and renal biopsy was performed. Pathologic study revealed membranous glomerulonephritis with deposition of IgG, IgM and complement C3, C1q, C4 and treponema antigen in the subepithelial area of the glomerular basement membrane. These phenomena suggest that treponemal antigen-antibody complexes were deposited in the glomeruli and activated the classic pathway of complements, leading to an immune complex nephritis. Immunologic study revealed that the patient had high circulating helper T cells (CD4 cells), low level of suppressor T cells (Leu2+15+ cells) with high CD4/CD8 ratio. It was accompanied by detectable circulating immune complex and high titer of T. pallidum hemagglutinin antibody titer. This change suggests that abnormal immune regulation may play an important role in the development of syphilitic glomerulonephritis.