Tricodisplasia espinulosa asociada a leucemia linfoblástica aguda en edad pediátrica: revisión de la literatura a propósito de un caso / Trichodysplasia spinulosa associated with acute lymphoblastic leukemia in pediatric age: review of the literature regarding a case

La tricodisplasia espinulosa es una patología viral infrecuente causada por un tipo de poliomavirus, el cual se da siempre en contexto de inmunosupresión. Existen reportes que estiman una seroprevalencia en adultos de 70%, y hasta 90% en inmu-nocomprometidos. El cuadro clínico se caracteriza por pápulas color piel hiperqueratósicas en zonas centro faciales, orejas y tronco, asintomáticas o con prurito escaso. Existen métodos de confirmación diagnóstica como PCR o test de Elisa, que no se encuentran disponibles en Chile. Por lo tanto, en nuestro contexto el estudio histopatológico es fun-damental, dada su accesibilidad y que los hallazgos de la biopsia son característicos. El manejo debe siempre considerar, de ser posible, disminuir la in-munosupresión del paciente. Otras medidas son: extracción manual de las lesiones y aplicación de cidofovir o valganciclovir tópicos

Trichodysplasia spinulosa is an infrequent viral pathology caused by a type of polyomavirus, which always occurs in context of immunosuppression. There are reports that estimate sero-prevalence in adults of 70%, and 90% in immunocompromised. Patients have numerous, mildly pruritic, folliculocentric, flesh-colored to pink papules with central keratinaceous spines. There are methods of diagnostic confirmation such as PCR or Elisa test, not available in Chile. The-refore, in our context the histopathological study is fundamental because biopsy findings are cha-racteristic. Management should always consider, if possible, decrease the immunosuppression of the patient. Other measures consist of manual extraction and cidofovir or topical valganciclovir.

Human polyomavirus infection: Cytological and molecular diagnosis / Infecção pelo poliomavírus humano: diagnóstico citológico e molecular

Summary Few studies directly compare urinary cytology with molecular methods for detecting BK and JC polyomaviruses. Reactivation of BKV infection is the main risk factor for the development of nephropathy in immunocompromised individuals. The limitation of the cytological method can be attributed to the stage where the infected cell does not have specific and sufficient morphological characteristics for a conclusive diagnosis and can be easily interpreted as degenerative alteration. Moreover, morphologically, it is not possible to differentiate the two types of viruses. Polymerase chain reaction (PCR), not only is a sensitive method, but also allows differentiation of viral types without quantification, and therefore is not indicative of nephropathy. According to the American Society of Nephrology, real-time PCR would be the gold standard to indicate nephropathy because it allows quantifying the number of viral copies.

Resumo Poucos estudos comparam diretamente a citologia urinária com métodos moleculares para detecção de poliomavírus BK e JC. A reativação da infecção por BKV é o principal fator de risco para o desenvolvimento de nefropatia em indivíduos imunocomprometidos. A limitação do método citológico pode ser atribuída ao estágio em que a célula infectada não possui características morfológicas específicas e suficientes para um diagnóstico conclusivo, podendo ser facilmente interpretada como alteração degenerativa. Além do mais, morfologicamente, não é possível diferenciar os dois tipos virais. A reação em cadeia pela polimerase (PCR), além de ser um método sensível, permite diferenciar os tipos virais sem quantificá-los, não sendo, portanto, indicativa de nefropatia. Segundo a American Society of Nephrology, a PCR em tempo real seria o padrão-ouro para indicar nefropatia, pois permite quantificar o número de cópias virais.

Merkel cell carcinoma in an immunosuppressed patient

Abstract Merkel cell carcinoma is an uncommon neuroendocrine carcinoma with a rising incidence and an aggressive behavior. It predominantly occurs in older patients, with onset occurring at a mean age of 75-80 years. Recognized risk factors are ultraviolet sunlight exposure, immunosuppression, and, more recently, Merkel cell polyomavirus. We report a case of Merkel cell carcinoma in a young HIV positive patient with Merkel Cell polyomavirus detected in the tumor.

Screening for BK virus nephropathy in kidney transplant recipients: comparison of diagnostic tests / Desempenho de métodos diagnósticos no rastreio de nefropatia pelo vírus BK em pacientes transplantados renais

Abstract Urine cytology and qPCR in blood and urine are commonly used to screen renal transplant recipients for polyomavirus-associated nephropathy (PVAN). Few studies, however, have directly compared these two diagnostic tests, in terms of their performance to predict PVAN. This was a systematic review in which adult (≥ 18 years old) renal transplant recipients were studied. A structured Pubmed search was used to identify studies comparing urine cytology and/or qPCR in urine and plasma samples for detecting PVAN with renal biopsy as the gold standard for diagnosis. From 707 potential papers, there were only twelve articles that matched the inclusion criteria and were analyzed in detail. Among 1694 renal transplant recipients that were included in the review, there were 115 (6.8%) patients with presumptive PVAN and 57 (3.4%) PVAN confirmed. In this systematic review, the qPCR in plasma had better performance for PVAN compared to urine cytopathology.

Resumo A citologia urinária e a reação da cadeia da polimerase em tempo real (qPCR) em amostras de sangue e/ou urina são comumente utilizados para rastrear nefropatia associada ao polyomavirus (PVAN), em pacientes transplantados renais. Entretanto, poucos estudos comparam diretamente esses testes diagnósticos quanto ao desempenho para predizer esta complicação. Aqui realizamos uma revisão sistemática na qual foram estudados pacientes transplantados renais adultos (≥ 18 anos). Uma pesquisa estruturada Pubmed foi utilizada para identificar estudos comparando citologia urinária e/ou qPCR em amostras de urina e plasma para detectar PVAN, utilizando a biópsia renal como padrão-ouro para o diagnóstico. Dentre os 707 artigos em potencial, apenas 12 atendiam aos critérios de inclusão e foram analisados em maior detalhe. Foram incluídos 1694 pacientes transplantados renais, entre os quais 115 (6,8%) classificados com PVAN presuntivo e 57 (3,4%) PVAN confirmado. Nessa revisão sistemática, o qPCR no plasma tive melhor desempenho para PVAN em comparação com citopatologia urinária.

Risk factors in the progression of BK virus-associated nephropathy in renal transplant recipients

BACKGROUND/AIMS: BK virus-associated nephropathy (BKVAN) is an important cause of allograft dysfunction in kidney transplant recipients. It has an unfavorable clinical course, and no definite treatment guidelines have yet been established. Here, we report our center's experience with biopsy-proven BKVAN and investigate factors associated with its progression. METHODS: From January 2004 to April 2013, 25 patients with BKVAN were diagnosed by biopsy at Seoul St. Mary's Hospital. Of the 25 patients, 10 were deceaseddonor transplant recipients and 15 were living-donor transplant recipients. Three of the patients underwent retransplantation. The primary immunosuppressant used was tacrolimus in 17 patients and cyclosporine in eight patients. RESULTS: BKVAN was observed at a mean duration of 22.8 ± 29.1 months after transplantation. The mean serum creatinine level at biopsy was 2.2 ± 0.7 mg/dL. BKVAN occurred with acute rejection in eight patients (28%). Immunosuppression modification was performed in 21 patients (84%). Additionally, leflunomide and intravenous immunoglobulin were administered to 13 patients (52%) and two (8%), respectively. Allograft loss occurred in five patients (27.8%) during the follow- up period at 0.7, 17.1, 21.8, 39.8, and 41.5 months after the BKVAN diagnosis. Advanced stages of BKVAN, increased creatinine levels, and accompanying acute rejection at the time of BKVAN diagnosis increased the risk of allograft failure. CONCLUSIONS: The clinical outcomes in patients with biopsy-proven BKVAN were unfavorable in the present study, especially in patients with advanced-stage BKVAN, poor renal function, and acute allograft rejection.

Treatment of BK virus-associated hemorrhagic cystitis with low-dose intravenous cidofovir in patients undergoing allogeneic hematopoietic cell transplantation

BACKGROUND/AIMS: BK virus (BKV) has been associated with late-onset hemorrhagic cystitis (HC) in recipients of hematopoietic stem cell transplantation (HSCT). Cidofovir has been used at higher doses (3 to 5 mg/kg/wk) with probenecid prophylaxis; however, cidofovir may result in nephrotoxicity or cytopenia at high doses. METHODS: Allogeneic HSCT recipients with BKV-associated HC are treated with 1 mg/kg intravenous cidofovir weekly at our institution. A microbiological response was defined as at least a one log reduction in urinary BKV viral load, and a clinical response was defined as improvement in symptoms and stability or reduction in cystitis grade. RESULTS: Eight patients received a median of 4 weekly (range, 2 to 11) doses of cidofovir. HC occurred a median 69 days (range, 16 to 311) after allogeneic HSCT. A clinical response was detected in 7/8 patients (86%), and 4/5 (80%) had a measurable microbiological response. One patient died of uncontrolled graft-versus-host disease; therefore, we could not measure the clinical response to HC treatment. One microbiological non-responder had a stable BKV viral load with clinical improvement. Only three patients showed transient grade 2 serum creatinine toxicities, which resolved after completion of concomitant calcineurin inhibitor treatment. CONCLUSIONS: Weekly intravenous low-dose cidofovir without probenecid appears to be a safe and effective treatment option for patients with BKV-associated HC.

Determinação do limite mínimo de detecção da técnica de Nested-PCR para os poliomavírus JC e BK / Assessment of minimum detection limit of Nested-PCR for JC and BK polyomaviruses

Introduction: Polyomaviruses (BKV and JCV) cause infection mainly in immunocompromised adults. A sensitive and specific diagnosis tool is fundamental to demonstrate the BKV and JCV infections. Nowadays many laboratories are using a PCR technique for detecting polyomaviruses genome in clinical samples. In this context, the purpose of this study is to determine the threshold of detection of the nested-PCR for polyomaviruses JC and BK. Methods: Serial dilutions of the samples of BKV and JCV of known concentration (100 copies/mL, 50 copies/mL, 25 copies/mL, 10 copies/mL, 5 copies/mL, and 1 copy/ml) were subjected to the technique of nested-PCR. All dilutions were tested 11 times to determine the minimum detection limit. Results: The minimum detection limit of the nested-PCR for JC and BK viruses was 25 copies/mL. This dilution (25 copies/mL) showed 100% PCR positive reaction. Furthermore, we found that weak positive results were obtained at dilutions of 1,5 and 10 copies/mL in some repetitions. Dilutions of 25, 50, and 100 copies/mL always had very positive results. Conclusions: These values are similar to those reported in other studies, contributing to the indication of this PCR for potential diagnostic purposes.

Introdução: Os poliomavírus (JCV e BKV) causam infecções principalmente em adultos imunocomprometidos. Um diagnóstico sensível e específico é de fundamental importância para os pacientes portadores de JCV e BKV. Atualmente alguns laboratórios têm utilizado a técnica de PCR para a detecção do material genético destes vírus em amostras clínicas. Assim, o objetivo deste estudo é determinar o limite mínimo de detecção da técnica de nested-PCR para os poliomavírus JC e BK. Métodos: Diluições seriadas (100 cópias/mL; 50 cópias/mL; 25 cópias/mL; 10 cópias/mL; 5 cópias/mL e 1 cópia/mL) de controles positivos comerciais de JCV e BKV com concentrações conhecidas foram submetidas à técnica de nested-PCR semi-duplex. Todas as diluições foram testadas 11 vezes para determinação do limite mínimo de detecção. Resultados: O limite mínimo de detecção da reação de nested-PCR para os vírus JC e BK foi de 25 cópias/mL para ambos, com 100% de positividade das diluições testadas na reação de PCR. Ainda, pudemos observar que resultados positivos fracos foram obtidos nas diluições de 1, 5 e 10 cópias/mL em algumas das repetições realizadas. As diluições de 25, 50 e 100 cópias/mL sempre obtiveram resultado rancamente positivo. Conclusões: Estes valores são semelhantes aos relatados em outros estudos, contribuindo para a indicação desta reação de PCR para potenciais fins diagnósticos.

JC polyomavirus infection in candidates for kidney transplantation living in the Brazilian Amazon Region

This study evaluated the relative occurrences of BK virus (BKV) and JC virus (JCV) infections in patients with chronic kidney disease (CKD). Urine samples were analysed from CKD patients and from 99 patients without CKD as a control. A total of 100 urine samples were analysed from the experimental (CKD patients) group and 99 from the control group. Following DNA extraction, polymerase chain reaction (PCR) was used to amplify a 173 bp region of the gene encoding the T antigen of the BKV and JCV. JCV and BKV infections were differentiated based on the enzymatic digestion of the amplified products using BamHI endonuclease. The results indicated that none of the patients in either group was infected with the BKV, whereas 11.1% (11/99) of the control group subjects and 4% (4/100) of the kidney patients were infected with the JCV. High levels of urea in the excreted urine, low urinary cellularity, reduced bladder washout and a delay in analysing the samples may have contributed to the low prevalence of infection. The results indicate that there is a need to increase the sensitivity of assays used to detect viruses in patients with CDK, especially given that polyomavirus infections, especially BKV, can lead to a loss of kidney function following transplantation.

High prevalence of the simultaneous excretion of polyomaviruses JC and BK in the urine of HIV-infected patients without neurological symptoms in São Paulo, Brazil / Alta prevalência de excreção simultânea de poliomavírus JC e BK na urina de pacientes HIV+ sem sintomas neurológicos em São Paulo, Brasil

OBJECTIVE: To evaluate the prevalence of the urinary excretion of BKV and JCV in HIV-infected patients without neurological symptoms. METHODS: Urine samples from HIV-infected patients without neurological symptoms were tested for JC virus and BK virus by PCR. Samples were screened for the presence of polyomavirus with sets of primers complementary to the early region of JCV and BKV genome (AgT). The presence of JC virus or BK virus were confirmed by two other PCR assays using sets of primers complementary to the VP1 gene of each virus. Analysis of the data was performed by the Kruskal-Wallis test for numerical data and Pearson or Yates for categorical variables. RESULTS: A total of 75 patients were included in the study. The overall prevalence of polyomavirus DNA urinary shedding was 67/75 (89.3%). Only BKV DNA was detected in 14/75 (18.7%) urine samples, and only JCV DNA was detected in 11/75 (14.7%) samples. Both BKV and JCV DNA were present in 42/75 (56.0%) samples. CONCLUSION: In this study we found high rates of excretion of JCV, BKV, and simultaneous excretion in HIV+ patients. Also these results differ from the others available on the literature.

OBJETIVO: Avaliar a prevalência de excreção urinaria de vírus JC (VJC) e vírus BK (VBK) em pacientes HIV+ sem sintomas neurológicos. MÉTODOS: Amostras de urina de pacientes HIV+ sem sintomas neurológicos foram testados para a presença de VJC e VBK através da técnica de PCR. As amostras foram triadas para a presença de poliomavírus com par de primers complementares a região precoce do genoma do VBK e do VJC (AgT). A presença foi confirmada através de dois outros ensaios de PCR dirigidos a região do gene VP1 de ambos os vírus. A análise estatística foi realizada com auxílio do teste de Kruskal-Wallis para dados numéricos e Pearson ou Yater para variáveis categóricas. RESULTADOS: Ao todo foram inclusos no estudo 75 pacientes. A prevalência geral de excreção de poliomavírus na urina foi de 67/75 (89,3%). O DNA do vírus VBK foi detectado em 14/75 (18,7%) das amostras de urina, e o DNA do VJC foi detectado em 11/75 (14,7%) das amostras testadas. Ambos os vírus estavam presentes simultaneamente em 42/75 (56%) das amostras de urina. CONCLUSÃO: Encontramos, no presente estudo, uma alta taxa de excreção de VJC, VBK e excreção simultânea em pacientes HIV+. Ainda, esses resultados diferem de outros disponíveis na literatura.

Polyoma BK virus: an emerging opportunistic infectious agent of the human central nervous system

BK virus, a double-stranded DNA virus, is a member of the Polyomaviridae family which is known to infect humans. Clinical evidence of disease is mostly encountered in immunosuppressed individuals such as AIDS patients or those who undergo renal or bone marrow transplantation where complications associated with BKV infection manifest commonly as a polyomavirus nephropathy or hemorrhagic cystitis, respectively. Recent evidence suggests that in addition to the JC virus (the other member of the same family known to be strongly neurotropic and responsible for the progressive multifocal leukoencephalopathy), BK virus can infect and cause clinically relevant disease in the human central nervous system. In this mini-review, an analysis of the literature is made. A special focus is given to alert clinicians to the possibility of this association during the differential diagnosis of infections of the central nervous system in the immunocompromised host.

BKV-infection in kidney graft dysfunction

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.

Detection and prevalence of polyoma virus BK among Iranian kidney transplant patients by a novel nested-PCR

BK virus is an increasingly recognized pathogen in transplant recipient patients associated with nephropathy and emerged as a cause of allograft failure linked to immunosuppressive regimens in renal transplant recipients. This study develops a sensitive PCR method to detect the viremia and viruria as well as the incidence of BK virus infection in renal transplant recipients. A nested PCR method was developed and a total of 45 paired serum and urine samples from renal transplant recipient patients were collected and tested with the developed assay. The threshold of the developed detection assay was 10 copies/ul of BKV DNA in samples. Our results also indicated that about 40% of the urine and 26.7% of serum samples were positive for BKV in renal transplant patients in this study. This Nested-PCR method was found a specific, sensitive and simple procedure for detection of viruria and viremia of BK virus in renal transplant recipients

Quantitation of BK Virus DNA for Diagnosis of BK Virus-Associated Nephropathy in Renal Transplant Recipients

Quantitative measurement of BK virus DNA (Q-BKDNA) has been used for the early diagnosis and monitoring of BK virus-associated nephropathy (BKVAN). This study was designed to determine the BKDNA cutoff for the diagnosis of BKVAN. Between June 2005 and February 2007, 64 renal transplant recipients taken renal biopsies due to renal impairment submitted plasma and urine for Q-BKDNA. Eight BKVAN patients (12.5%) had median viral loads of 6.0 log(10) copies/mL in plasma and 7.3 log(10) copies/mL in urine. Among 56 non-BKVAN patients, 45 were negative for Q-BKDNA; 4 were positive in plasma with a median viral load of 4.8 log(10) copies/ mL, and 10 were positive in urine with a median viral load of 4.8 log(10) copies/mL. Receiver operating characteristic curve analysis showed that a cutoff of 4.5 log(10) copies/mL in plasma and a cutoff of 5.9 log(10) copies/mL in urine had a sensitivity of 100% and a specificity of 96.4%, respectively. A combined cutoffs of 4 log(10) copies/ mL in plasma and 6 log(10) copies/mL in urine had better performance with a sensitivity of 100% and a specificity of 98.2% than each cutoff of urine or plasma. QBKDNA with the combined cutoffs could reliably diagnose BKVAN in renal transplant recipients.

Neuropatía por virus BK post trasplante renal diagnostico y seguimiento por PCR en tiempo real / BK virus nephropathy after renal transplantation: Diagnosis and prognosis by real time PCR

La nefropatía producida por el virus BK puede llevar a la pérdida del trasplante renal. El diagnóstico etiológico es importante debido a que la clínica no permite diferenciar entre nefropatía por virus BK y rechazo agudo, en donde los tratamientos de estas dos entidades son diametralmente opuestos. El desarrollo reciente de métodos moleculares muy sensibles y específicos como PCR y PCR en tiempo real para virus BK permiten un diagnóstico de certeza en forma rápida y cuantificar la carga viral presente. El diagnóstico de nefropatía por virus BK se realiza por inmunohistoquímica en una biopsia renal, pero dada la naturaleza multifocal de las lesiones, la sensibilidad no siempre es del 100%. Los nuevos métodos de PCR para detectar virus BK en sangre y orina contribuyen al diagnóstico de nefropatía de una manera más normatizada y menos invasiva. Más aún, la cuantificación del virus BK en sangre por PCR en tiempo real, ha demostrado ser útil en el diagnóstico y monitoreo de esta enfermedad. En este trabajo se presenta el caso de una paciente transplantada renal con nefropatía por virus BK y el desarrollo de un método de PCR en tiempo real para la detección de virus BK en sangre y orina. Esta nueva metodología confirmó el diagnóstico de nefropatía por virus BK lo que permitió un cambio en el esquema de inmunosupresión y la instauración de un tratamiento que pudo ser monitorizado utilizando la carga viral.

BK virus nephropathy may lead to kidney transplant failure. BK infection and acute rejection are clinically undistinguishable, therefore diagnosis of these entities is critical to establish the correct treatment. The new molecular methods using PCR and real time PCR have significantly contributed to the rapid and sensitive diagnosis of BK virus. Furthermore, viral load determination in plasma has significantly been associated with BK virus nephropathy. Definite diagnosis of nephropathy requires renal biopsy, although due to the multifocal nature of the disease sensitivity may be less than 100%. BK detection in blood and urine by PCR has contributed to the diagnosis of nephropathy in a more standardized and less invasive way. Recently, quantification of BK virus in plasma has been used for the diagnosis and monitoring of this disease. In the present study, we describe the validation of a real time PCR method for BK virus detection in plasma and urine and its application for diagnosis and monitoring in a renal transplant patient with nephropathy.

BK virus infection in a renal transplant Saudi child

BK human polyomavirus BKV causes an asymptomatic primary infection in children, but later, establishes latency mainly in the urinary tract. Virus-host interactions influencing persistence and pathogenicity are not well-understood. We present here a 12-year-old Saudi boy, who had renal transplant in Egypt. Seven months later, he was admitted to our Pediatric Nephrology Unit as a case of renal impairment. He developed BKV infection, diagnosed and successfully managed in our hospital. This case demonstrates the expanding clinical importance of BKV in a post renal transplant patient. This virus can be detected in transitional cells in the urine decoy cells using cytology. Testing for BKV deoxyribonucleic acid in urine and blood is an early detection assay, and can be used as a screening test in the early stages. The early reduction of immunosuppression can improve the prognosis. No specific antiviral treatment has been established yet. This is the first report of detecting BK virus in a Saudi post-transplant child in urine and blood specimens by using polymerase chain reaction