ROLE OF ELECTRON-MICROSCOPY IN TRANSPLANT RENAL PATHOLOGY

The crucial role that electron microscopy plays in diagnostic renal pa thology is undisputed. By allowing recognition of findings not identif iable by light microscopic evaluation, electron microscopy has contrib uted significantly to the understanding of renal diseases and has prov en to be of unquestionable value in many diagnostic situations. Howeve r, the percentage of cases in which electron microscopic examination a dds important information that is either key for establishing or confi rming a diagnosis or provides valuable data that influence patient's m anagement remains controversial. This figure depends on the renal biop sy service that is surveyed, but it is reported that on the average ul trastructural evaluation is of Value in approximately 30 to 45% of the cases. Correct interpretation of a renal biopsy depends on the abilit y to correlate light, immunofluorescence, and ultrastructural findings . In contrast, the role of electron microscopy in the examination of r enal transplant specimens remains controversial. Many centers do not u se routine electron microscopy to examine these specimens and insist t hat there are only a few specific indications that require ultrastruct ural evaluation. There is general agreement among renal pathologists t hat electron microscopy is of importance in the evaluation of renal sp ecimens from patients with proteinuria to distinguish between transpla nt glomerulopathy, recurrent or de novo glomerulonephritis in order to correctly manage these patients and predict survival of the graft. Th e other possible indications are much more controversial. This paper s ummarizes and critically reviews the literature available on this subj ect and defines recommendations based on the information available at the current time.