A case of bizarre posttransplant anti-glomerular basement membrane disease

The non-collagenous (NC1) domain of α3 and α5 chains of type IV collagen are eminent targets of abnormal immune response in anti-glomerular basement membrane (anti-GBM) disease, which can be diagnosed by the presence of strong linear IgG staining along GBM detected by direct immunofluorescence. The presence of linear GBM fixation in renal allograft is a rare finding. We observed a 33-year-old male with de novo renal failure in a kidney transplant. An examination of a kidney biopsy specimen revealed, in light microscopy, mild mesangial hypercellularity together with mild focal interstitial fibrosis and sparse inflammatory infiltrate. In immunofluorescence microscopy strong linear IgG staining along the capillary walls was seen. Serum anti-GBM antibodies were negative and no mutation in exons coding NC1 domains of α3 and α5 chains of type IV collagen were detected. We described a rare case of a patient with atypical anti-GBM disease in renal allograft, caused probably by the same process which affected the native kidneys.