Electron microscopic evaluation of renal allograft biopsies: Its role in graft dysfunction

Electron microscopic examination is often not considered an essential diagnostic modality for evaluation of renal transplant biopsies in patients with graft dysfunction. However, recent reports suggest that ultrastructural evaluation of renal graft biopsies from patients presenting with allograft dysfunction is required to diagnose early changes of chronic rejection. These early ultrastructural lesions involve both glomerular and interstitial peritubular renal capillaries. The routine ultrastructural examination of renal graft biopsies in patients with chronic graft dysfunction can reduce the non-specific diagnosis of interstitial fibrosis and tubular atrophy – not otherwise specified. Ultrastructural evaluation of renal graft biopsies from patients presenting with proteinuria is also important along with routine histology and immunofluorescence to diagnose recurrent or de novo glomerular conditions and differentiate them from transplant glomerulopathy. The definite role of electron microscope in acute rejection is still controversial. The limitations and various aspects of application of electron microscopy in the evaluation of renal graft biopsies are discussed. These include its application in the diagnosis of rejection, transplant glomerulopathy, infections and in recurrent and de novo glomerular diseases. Ancillary techniques including immunoelectron microscopy are also described.