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Human Polyoma Virus in Kidney Transplants: SV40 T-Antigen Demonstration in the Urine
Human Polyoma Virus in Kidney Transplants: SV40 T-Antigen Demonstration in the Urine E. von Willebrand, J. Savikko, J. Merenmies, and H. Jalanko ABSTRACT We wanted to develop an immunostaining method of urine cytopreparations to detect polyoma virus infection by using fresh urine samples and staining with the monoclonal SV40 antibody and to compare the findings to the demonstration of decoy cells in the urine or to kidney histology. Routine urine samples from pediatric kidney transplant patients were collected either early after transplantation or later, cytocentrifuged, and immunostained with SV40-T-antibody. The number of SV40-T-antigen–positive epithelial cells was counted in the cytopreparations and compared to the findings in routine urine cytology and transplant histology. Immunostaining of urine cytology with SV40-T-ab demonstrated clearly that the infected epithelial cells and the rate of infection could be estimated by semiquantitative counting. There was strong correlation between the findings in the urine and in the biopsies, but in the urine preparations the number of infected cells was much higher than in the biopsies. The high number of SV40-positive cells in the urine also correlated to the severity of clinical infection and to the state of transplant. Immunostaining of urine cytology with SV40-T-antibody seems to be useful in the diagnosis and follow-up of polyoma virus reactivation disease in transplant patients, especially in children with renal transplants.
H
UMAN POLYOMA VIRUS can cause interstitial nephritis in kidney transplants after reactivation of latent virus in renal epithelium. Currently, there are no exact data about the incidence of polyoma virus infection in transplant patients or about the effect on long-term transplant outcome. Diagnosis of polyoma virus disease has been based on transplant histology with cytopathic changes in the tubules associated with focal or diffuse tubulointerstitial inflammation and atrophy, findings similar to chronic allograft nephropathy. Immunohistological staining of kidney biopsies with monoclonal SV40-T-antibody and demonstration of decoy cells in the urine have recently been found useful in the diagnosis. We wanted to develop an immunostaining method of urine cytopreparations using fresh urine samples and staining with the monoclonal SV40 antibody and to compare the findings to the demonstration of decoy cells in the urine or to kidney histology.
METHODS Routine urine samples from pediatric kidney transplant patients were collected either early after transplantation or later, cytocentrifuged, and immunostained with SV40-T-antibody using a sensitive three© 2005 by Elsevier Inc. All rights reserved. 360 Park Avenue South, New York, NY 10010-1710 Transplantation Proceedings, 37, 945–946 (2005)
layer immunoperoxidase method.1 The number of SV40-T-antigen– positive epithelial cells was counted in the cytopreparations and compared to the findings in routine urine cytology and transplant histology.2
RESULTS
Twenty urine samples from transplanted patients were analyzed. In five cases, clear findings of polyoma virus infection were seen, and in 15 cases the urine specimens were normal (demonstrating only some urothelial cells and no signs of polyoma virus). Immunostaining of urine cytology with SV40-T-antibody demonstrated clearly that the infected epithelial cells and the rate of infection could be From the Transplantation Laboratory, University of Helsinki and Hospital for Children and Adolescents, Helsinki University Central Hospital, Helsinki, Pa˘ijat-Háme Central Hospital, Lahti, Finland. Supported in part by Finska Läkaresällskapet and the Finnish Medical Foundation. Address reprint requests to Eva von Willebrand, Transplantation Laboratory, Haartman Institute P.O. Box 21 (Haartmaninkatu 3), FIN-00014 University of Helsinki, Finland. E-mail: Eva.von. [email protected] 0041-1345/05/$–see front matter doi:10.1016/j.transproceed.2004.12.073 945
946
Fig 1. Photomicrographs of immunohistochemical findings of polyoma virus infected tubular cells in transplanted kidneys. SV-40 T-antigen–positive shedded tubular cells in the urine, immunostaining with monoclonal antibody. The viral inclusions in the tubular cell nuclei are stained positively (Magnification ⫻400.)
estimated by semiquantitative counting (Figs 1 and 2). There was strong correlation between the findings in the urine and in the biopsies, but in the urine preparations the number of infected cells was much higher than in the biopsies. The high number of SV40-positive cells in the urine also correlated to the severity of clinical infection and to the state of transplant. CONCLUSION
Immunostaining of urine cytology with SV40-T-antibody seems to be useful in the diagnosis and follow-up of
VON
WILLEBRAND, SAVIKKO, MERENMIES ET AL
Fig 2. Immunohistochemical findings of polyoma virus-infected tubular cells seen in histological biopsies stained with monocolonal SV-40 T-antibody. Only scattered positive cells are seen in the cortex, whereas strongly positive findings were seen in the urine of the same patients. (Magnification ⫻100.)
polyoma virus reactivation disease in transplant patients, especially in children with renal transplants.
REFERENCES 1. von Willebrand E, Zola H, Häyry P: Thrombocyte aggregates in renal allografts. Analysis by the fine needle aspiration biopsy and monoclonal anti-thrombocyte antibodies. Transplantation 39:258, 1985 2. von Willebrand E, Lautenschlager I: Organ transplantation. In McKee, WG (ed): Diagnostic Cytopathology 2. London: Churchill Livingstone; 2003, p 551
H
UMAN POLYOMA VIRUS can cause interstitial nephritis in kidney transplants after reactivation of latent virus in renal epithelium. Currently, there are no exact data about the incidence of polyoma virus infection in transplant patients or about the effect on long-term transplant outcome. Diagnosis of polyoma virus disease has been based on transplant histology with cytopathic changes in the tubules associated with focal or diffuse tubulointerstitial inflammation and atrophy, findings similar to chronic allograft nephropathy. Immunohistological staining of kidney biopsies with monoclonal SV40-T-antibody and demonstration of decoy cells in the urine have recently been found useful in the diagnosis. We wanted to develop an immunostaining method of urine cytopreparations using fresh urine samples and staining with the monoclonal SV40 antibody and to compare the findings to the demonstration of decoy cells in the urine or to kidney histology.
METHODS Routine urine samples from pediatric kidney transplant patients were collected either early after transplantation or later, cytocentrifuged, and immunostained with SV40-T-antibody using a sensitive three© 2005 by Elsevier Inc. All rights reserved. 360 Park Avenue South, New York, NY 10010-1710 Transplantation Proceedings, 37, 945–946 (2005)
layer immunoperoxidase method.1 The number of SV40-T-antigen– positive epithelial cells was counted in the cytopreparations and compared to the findings in routine urine cytology and transplant histology.2
RESULTS
Twenty urine samples from transplanted patients were analyzed. In five cases, clear findings of polyoma virus infection were seen, and in 15 cases the urine specimens were normal (demonstrating only some urothelial cells and no signs of polyoma virus). Immunostaining of urine cytology with SV40-T-antibody demonstrated clearly that the infected epithelial cells and the rate of infection could be From the Transplantation Laboratory, University of Helsinki and Hospital for Children and Adolescents, Helsinki University Central Hospital, Helsinki, Pa˘ijat-Háme Central Hospital, Lahti, Finland. Supported in part by Finska Läkaresällskapet and the Finnish Medical Foundation. Address reprint requests to Eva von Willebrand, Transplantation Laboratory, Haartman Institute P.O. Box 21 (Haartmaninkatu 3), FIN-00014 University of Helsinki, Finland. E-mail: Eva.von. [email protected] 0041-1345/05/$–see front matter doi:10.1016/j.transproceed.2004.12.073 945
946
Fig 1. Photomicrographs of immunohistochemical findings of polyoma virus infected tubular cells in transplanted kidneys. SV-40 T-antigen–positive shedded tubular cells in the urine, immunostaining with monoclonal antibody. The viral inclusions in the tubular cell nuclei are stained positively (Magnification ⫻400.)
estimated by semiquantitative counting (Figs 1 and 2). There was strong correlation between the findings in the urine and in the biopsies, but in the urine preparations the number of infected cells was much higher than in the biopsies. The high number of SV40-positive cells in the urine also correlated to the severity of clinical infection and to the state of transplant. CONCLUSION
Immunostaining of urine cytology with SV40-T-antibody seems to be useful in the diagnosis and follow-up of
VON
WILLEBRAND, SAVIKKO, MERENMIES ET AL
Fig 2. Immunohistochemical findings of polyoma virus-infected tubular cells seen in histological biopsies stained with monocolonal SV-40 T-antibody. Only scattered positive cells are seen in the cortex, whereas strongly positive findings were seen in the urine of the same patients. (Magnification ⫻100.)
polyoma virus reactivation disease in transplant patients, especially in children with renal transplants.
REFERENCES 1. von Willebrand E, Zola H, Häyry P: Thrombocyte aggregates in renal allografts. Analysis by the fine needle aspiration biopsy and monoclonal anti-thrombocyte antibodies. Transplantation 39:258, 1985 2. von Willebrand E, Lautenschlager I: Organ transplantation. In McKee, WG (ed): Diagnostic Cytopathology 2. London: Churchill Livingstone; 2003, p 551