ANTIBODIES DIRECTED AGAINST TUBULAR BASEMENT-MEMBRANES IN HUMAN RENAL-ALLOGRAFT RECIPIENTS

Among 101 renal allograft recipients, 4 had circulating Ig[immunoglobulin]G antibodies [Ab] of various subclasses directed against the tubular basement membrane (TBM) of the graft, IgG4 was demonstrated along the TBM without C3 [complement component 3] and tubulo-interstitial changes TBM of renal medullary tissue. When tested against a panel of kidney biopsies, the anti-TBM Ab bound to almost all kidneys. The effects of the Ab could be studied in 3 of the 4 recipients, since 1 graft was removed for technical reasons 1 day after transplantation. In 2 grafts tubulo-interstitial changes developed but there was no specific binding of IgG along the TBM. The histological changes might be related to the circulating anti-TMB Ab. In one graft, IgG4 demonstrated long the TBM without C3, and tubulo-interstitial changes did not develop.