Urinary cytopathologic findings in renal allograft recipients in Sudan: Trends, outcome and challenges

Abstract

Urine cytology allows frequent monitoring of the intragraft events in renal transplantation and detection of infections associated with renal transplantation as a result of immunosuppression, specifically BK polyoma virus (Decoy cells). We conducted a cross-sectional study aimed to demonstrate the urinary cytomorphological changes among renal allograft recipients. We studied urine samples from 182 renal adult allograft recipients. All grafts were obtained from live donors. All the study population was under immunosuppressive drugs (Cyclosporine, Tacrolimus or azathioprine). Fourteen samples (7.6%) were collected during the first three months following transplantation. The slides of the centrifuged precipitates were stained with Papanicolaou and Diff Quick stains. The slides were screened by a cyto-screener and examined by a consultant cytopathologist for the presence of infectious agents and benign and malignant cellular changes. Of the 182 cases, 120 (65.9%) were negative for cytological changes, 45 (24.7%) showed bacterial infection, eight (4.4%) had BK polyoma virus infection (Decoy cells), four (2.2%) had human papilloma virus (HPV) infection (Koilocytosis) (Figure 1), three (1.6%) showed candida and two (1.1%) had cytomegalovirus infection. Renal transplant recipients are at a high risk for developing infections, including opportunistic infections; this is generally attributed to the immunosuppression status and epidemiologic exposure to infections. During the first posttransplantation year, 40–50% of recipients experience at least one infection. Smears consistent with bacterial infections were the most common finding in our study; they revealed polymorphs, macrophages, necrotic debris and background of bacteria. In our study, eight (4.4%) cases were diagnosed to have BK polyoma virus cytological changes (Decoy cells). Human polyoma viruses are members of the Papova virus family, which have a double strand DNA-genome. Recently, BK virus has been recognized as a cause of severe renal allograft dysfunction and potential graft loss, which are characterized by the presence of Decoy cells that were reported to present in 10–19.7% of urine samples from renal transplant (RT) patients.