RESUMO
BACKGROUND: BK polyomavirus (BKPyV)-associated nephropathy (BKPyVAN) is a consequence of BKPyV replication in the urinary tract in kidney transplant recipients (KTR). OBJECTIVES: The objectives were to determine the prevalence of BKPyV replication and BKPyVAN, risk factors associated to sustained viremia and BKPyVAN, and viremia cut-off that best predict the occurrence of sustained viremia and nephropathy in KTR of a single University Hospital Kidney Transplant Center. PATIENTS AND METHODS: All KTR undergoing transplantation from August 2010 to December 2011 were enrolled and monitored up to 2 years posttransplantation for BKPyV viruria by decoy cells shedding or polymerase chain reaction (PCR) and viremia by PCR. Kidney biopsy was indicated if sustained viremia (two or more viremia above 10 000 copies/mL) to confirm BKPyVAN diagnosis. RESULTS: In this study, 326 transplants were performed and 246 patients were included. Prevalence of viruria was 36.9%, viremia 22.3% and nephropathy 3.2%. Male gender was the only risk factor associated to sustained viremia or nephropathy. Cut-off value of viremia that best discriminates the progression to sustained viremia and to BKPyVAN was 37 488 and 44 956 copies/mL, respectively. CONCLUSIONS: Prevalence of viruria, viremia, and nephropathy were similar to those reported in literature but the cut-off value of viremia that best discriminates the risk of progression to nephropathy was greater than the value usually reported, which is 10 000 copies/mL.
Assuntos
Vírus BK/isolamento & purificação , Nefropatias/epidemiologia , Infecções por Polyomavirus/epidemiologia , Infecções Tumorais por Vírus/epidemiologia , Viremia/diagnóstico , Adolescente , Adulto , Idoso , Vírus BK/fisiologia , Biópsia , DNA Viral/isolamento & purificação , Progressão da Doença , Feminino , Rejeição de Enxerto/sangue , Rejeição de Enxerto/epidemiologia , Rejeição de Enxerto/patologia , Rejeição de Enxerto/virologia , Humanos , Terapia de Imunossupressão/efeitos adversos , Terapia de Imunossupressão/métodos , Rim/patologia , Rim/virologia , Nefropatias/diagnóstico , Nefropatias/patologia , Nefropatias/virologia , Transplante de Rim/efeitos adversos , Masculino , Pessoa de Meia-Idade , Seleção de Pacientes , Infecções por Polyomavirus/diagnóstico , Infecções por Polyomavirus/patologia , Infecções por Polyomavirus/virologia , Valor Preditivo dos Testes , Prevalência , Estudos Prospectivos , Fatores de Risco , Infecções Tumorais por Vírus/diagnóstico , Infecções Tumorais por Vírus/patologia , Infecções Tumorais por Vírus/virologia , Viremia/epidemiologia , Viremia/virologia , Adulto JovemRESUMO
BACKGROUND: BK virus (BKV) may reactivate in kidney allograft recipients ultimately leading to BKV nephropathy and graft loss. Decoy cells (DCs) are one of the early marks of BKV reactivation, and these can be detected in the urine sediment. METHODS: A cohort of 102 kidney transplant patients was followed during months 3 and 6 after the transplant procedure. Urine samples were obtained to detect the presence of DC in the fresh and unstained urine sediment under bright field microscopy (BFM), in concomitance to the determination of the amount of BK viruria by qPCR. RESULTS: Decoy cells were found in 14.7% of patients (15/102). There was a strong agreement (P < 0.001) between qualitative DC detection by two experienced analysts and by qPCR. The positive predictive value, negative predictive value, specificity, and accuracy of BFM were 80%, 75%, 97%, and 75%, respectively. Test sensitivity was 16%. The comparative method was the qPCR. CONCLUSIONS: Despite its limited sensitivity, BFM of unstained urine sediment is an easily available, fast and cheap method to identify DCs in the population of kidney allograft recipients. The diagnostic performance of BFM on the hands of less experienced analysts deserves further investigation.
Assuntos
Vírus BK/patogenicidade , Células Epiteliais/patologia , Transplante de Rim/efeitos adversos , Microscopia , Infecções por Polyomavirus/patologia , Adulto , Idoso , Aloenxertos/virologia , Vírus BK/genética , Estudos de Coortes , DNA Viral/urina , Células Epiteliais/virologia , Feminino , Sobrevivência de Enxerto , Humanos , Nefropatias/cirurgia , Masculino , Pessoa de Meia-Idade , Infecções por Polyomavirus/urinaRESUMO
Introducción: La nefropatía del poliomavirus tipo BK, o nefropatía por VBK, se asocia a disfunción del injerto renal teniendo como factor de riesgo del donante, la presencia de virus VBK activo, infección por Citomegalovirus. La presencia de células de Decoy en orina y de virus BK en el plasma son los marcadores de la replicación del virus del polioma. Materiales y métodos: Estudio retrospectivo observacional en pacientes sometidos a trasplante renal en el período: enero 2013 a diciembre 2014. Los métodos empleados para establecer el diagnóstico incluyeron la determinación de las características clínicas; el hallazgo de células de Decoy en orina; reacción en cadena de polimerasa (PCR) en sangre para detectar el virus BK; inmunohistoquímica en biopsia renal. Resultados: De 53 pacientes con trasplante renal, cinco desarrollaron nefropatía inducida por virus del polioma humano. De ellos, cuatro tuvieron donante cadavérico y uno, donante vivo relacionado. El deterioro de la función renal se estableció 3 a 7 meses postrasplante, en pacientes que recibieron terapia inmunosupresora a base de micofenolato de mofetilo o tacrolimus. De los cinco pacientes en uno se evidenció células de Decoy en orina positivo y todos tenían carga viral plasmática positiva. Discusión: La nefropatía por Virus BK en pacientes trasplantados renales constituye una infección secundaria relacionada con el rechazo, el diagnóstico se establece con el análisis de marcadores específicos.
Introduction: Polyomavirus type BK (BKV) nephropathy is associated with renal transplant dysfunction, since donos carrying the VBK hold a risk factor of the concurrent cytomegalovirus infection. The presence of Decoy cells in urine and the VBK in plasma are the markers of polioma virus replication. Methods: Retrospective observational study focused on patients who received renal transplants in the period between January 2013 to December 2014. In order to make the diagnosis more accurate, we tested for clinical characteristics; the presence of Decoy cells in urine; polymerase chain reaction (PCR) blood test to detect the BK virus and immune histochemical test on renal biopsies. Results: Of 53 renal transplant patients, five developed nephropathy induced by human polyoma virus. Four received transplants from cadaveric donors and one from a living donor. Renal function deterioration was seen between three to seven months after the renal transplant in those patients receiving immunosuppression with mycophenolate mofetil or tacrolimus. Of the five patients, one tested positive for decoy cells in urine, and they all tested positive for plasmatic viral load. Discusion: The presence of BKV nephropathy in renal transplant patients is a secondary infection that might cause organ rejection. The diagnosis is made with specific biomarkers.
Assuntos
Humanos , Masculino , Feminino , Transplante de Rim , Polyomavirus , Nefropatias , Doadores de Tecidos , Reação em Cadeia da Polimerase , Vírus BK , CitomegalovirusRESUMO
INTRODUCTION: BKV nephropathy (BKN) causes kidney graft loss, whose specific diagnosis is invasive and might be predicted by the early detection of active viral infection. OBJECTIVE: Determine the BKV-infection prevalence in late kidney graft dysfunction by urinary decoy cell (DC) and viral DNA detection in urine (viruria) and blood (viremia; active infection). METHODS: Kidney recipients with >1 month follow-up and creatinine >1.5 mg/dL and/or recent increasing >20 percent (n = 120) had their urine and blood tested for BKV by semi-nested PCR, DC searching, and graft biopsy. PCR-positive patients were classified as 1+, 2+, 3+. DC, viruria and viremia prevalence, sensitivity, specificity, and likelihood ratio (LR) were determined (Table 2x2). Diagnosis efficacy of DC and viruria were compared to viremia. RESULTS: DC prevalence was 25 percent, viruria 61.7 percent, and viremia 42.5 percent. Positive and negative patients in each test had similar clinical, immunossupressive, and histopathological characteristics. There was no case of viremia with chronic allograft nephropathy and, under treatment with sirolimus, patients had a lower viruria prevalence (p = 0.043). Intense viruria was the single predictive test for active infection (3+; LR = 2.8).1,6-4,9 CONCLUSION: DC, BKV-viruria and -viremia are commun findings under late kidney graft dysfunction. Viremia could only be predicted by intense viruria. These results should be considered under the context of BKN confirmation.