Nephrol Dial Transplant (2002) 17: 1491-1496
© 2002 European Renal Association-European Dialysis and Transplant Association
Lectin staining for urine cytologic monitoring after kidney transplantation
1 Abteilung Nephrologie und Rheumatologie, 2 Klinik für Transplantationschirurgie, 3 Abteilung Klinische Chemie and 4 Zentrum für Pathologie, Georg-August Universität Göttingen, Robert-Koch-Straße 40, D-37075 Göttingen, Germany
Background. Urine cytology, although considered a valuable diagnostic tool in the monitoring of kidney graft function, is hampered by difficulty in differentiating the nucleated non-squamous cells in urine using conventional techniques. We have now developed a method for the simple identification of urinary cell types by lectin staining.
Methods. Acetone-fixed cytopreparations of urinary sediments were incubated with the lectin combination Sophora Japonica agglutinin (SJA; rhodamine-labelled) and Erythrina cristagalli agglutinin (ECA; fluorescein isothiocyanate (FITC)-labelled) for 15 min, followed by staining of the nuclei with 4',6-diamidino-2-phenylindole (DAPI). The courses of 38 patients were serially monitored after kidney transplantation during the period in hospital.
Results. Nucleated urinary cell types could be easily identified from one specimen by their characteristic lectin-binding pattern using triple-immunofluorescence microscopy (FITC/rhodamine/ultra violet), permitting a differentiation between proximal (SJA+/ECA+) and distal tubules (SJA-/ECA+), collecting ducts (SJA+/ECA-) and lymphocytes (SJA-/ECA-). Stable graft function was characterized by low numbers of lymphocytes, tubular cells and urothelia. During rejection episodes, but not graft dysfunction unrelated to rejection, urinary excretion of lymphocytes as well as of distal tubular cells (from 1.0 to 6.0 and from 1.4 to 4.0 per 10 high-power fields, respectively) increased significantly up to 3 days prior to clinical diagnosis.
Conclusions. Lectin staining facilitates unambiguous differentiation of the urinary cell types, in particular the various tubular epithelial cells, which are otherwise difficult to identify. This technique provides a rapid and easily applicable tool to evaluate the significance of the respective cell types in the monitoring of kidney graft function.
Keywords: graft dysfunction; kidney transplantation; lectin; rejection; Tx monitoring; urine cytology
Correspondence and offprint requests to: Clemens Grupp, Abteilung Nephrologie und Rheumatologie, Georg-August Universität Göttingen, Robert-Koch-Straße 40, D-37075 Göttingen, Germany. Email: cgrupp{at}gwdg.de