Nephropathy of Secondary Syphilis

Two patients illustrate the clinical and pathological spectrum of renal involvement in secondary syphilis. The first patient had a transient nephrotic syndrome (acute syphilitic nephrosis), with mild proliferative changes shown on light microscopy and subepithelial electron-dense deposits on electron microscopy. The second patient had hemorrhagic nephritis, with diffuse, axial, proliferative and exudative changes shown on light microscopy and subepithelial hump-like deposits on electron microscopy. Immunofluorescent study, done in the first case, revealed subepithelial deposits of IgG and complement (β₁c-globulin) along the glomerular basement membrane. This provides further evidence that the nephropathy of secondary syphilis is an immune-complex disease.