Fine-needle cytology in the monitoring of human renal allograft progress

Abstract

The differential diagnosis of early post-transplant renal dysfunction is complex. Clinical evaluation alone is often inaccurate and it is usually necessary to have recourse to additional investigation. Imaging methods, biochemistry and needle-core biopsy have all proved invaluable in this way, but for making consecutive evaluations of renal allografts, fine-needle aspiration cytology has now emerged as a safe, rapid and reliable addition. Indeed, with a such a negligible incidence of complications, aspirates may be taken on a regular basis with the information obtained not only helping in routine diagnosis but also providing a useful research insight into the dynamic nature of the rejection process. The technique has evolved mainly over the past two decades, initially being based on traditional, semi-quantitative, morphometric cytology. However, monoclonal antibody technology and immunocytochemistry have been developing over the same time period and much use has been made of such procedures as immunofluorescence, immunoperoxidase, immunogold-silver and immunoalkaline phosphatase in further, more subtle analyses of aspirated cell populations. Renal aspiration cytology has become an established technology which is now being adapted to the study of liver, pancreas and even lung allografts.