Tubular basement membrane antibody-induced interstitial nephritis in systemic lupus erythematosus.

Interstitial nephritis characterized by linear staining for human immunoglobulin G (IgG) along the tubular basement membrane of proximal renal tubules is described in a child with systemic lupus erythematosus (SLE). Autoantibodies reacting with the tubular basement membrane of the proximal renal tubules and Bowman capsule of glomeruli were present in serum. The autoantibodies were specific and could be absorbed with a normal human renal cortical fraction. The findings suggest that in addition to the well-known, immune complex-mediated injury, autoantibody-induced interstitial nephritis can also rarely occur in SLE.