JC virus/human immunodeficiency virus 1 co-infection in the Brazilian Amazonian region

Abstract JC virus (JCV) is a member of the Polyomaviridae family and is associated to a severe disease known as progressive multifocal leukoencephalopathy, PML, which is gradually increasing in incidence as an opportunistic infection among AIDS patients. The present study aimed to investigate the occurrence of JCV among HIV-1 carriers including their types and molecular subtypes and the possible association with disease. Urine samples from 66 HIV-1 infected subjects were investigated for the presence of the virus by amplifying VP1 (215 bp) and IG (610 bp) regions using the polymerase chain reaction. JCV was detected in 32% of the samples. The results confirmed the occurrence of type B (subtype Af2); in addition, another polyomavirus, BKV, was also detected in 1.5% of samples of the HIV-1 infected subjects. Apparently, there was no significant difference between mono- (HIV-1 only) and co-infected (HIV-1/JCV) subjects regarding their TCD4+/TCD8+ lymphocyte counts or HIV-1 plasma viral load. Self admitted seizures, hearing and visual loses were not significantly different between the two groups.

Natalizumab treatment for multiple sclerosis: updates and considerations for safer treatment in JCV positive patients / Tratamento com Natalizumabe para esclerose múltipla: atualizações e considerações para um tratamento mais seguro em pacientes positivos para o VJC

Natalizumab is currently one of the best options for treatment of patients with Multiple Sclerosis who have failed traditional prior therapies. However, prolonged use, prior immunosuppressive therapy and anti-JCV antibody status have been associated with increased risk of developing progressive multifocal leukoencephalopathy (PML). The evaluation of these conditions has been used to estimate risks of PML in these patients, and distinct (sometimes extreme) approaches are used to avoid the PML onset. At this time, the biggest issue facing the use of Natalizumab is how to get a balance between the risks and the benefits of the treatment. Hence, strategies for monitor JCV-positive patients undergoing Natalizumab treatment are deeply necessary. To illustrate it, we monitored JCV/DNA in blood and urine of a patient receiving Natalizumab for 12 months. We also bring to discussion the effectiveness of the current methods used for risk evaluation, and the real implications of viral reactivation.

Natalizumabe é atualmente uma das melhores opções para o tratamento de pacientes com Esclerose Múltipla que não respondem aos tratamentos tradicionais. No entanto, o seu uso prolongado, o uso de terapia imunossupressora prévia e o status sorológico antivírus JC têm sido associados com o risco aumentado de desenvolvimento de Leucoencefalopatia Multifocal Progressiva (LEMP). A avaliação destas condições tem sido utilizada para estimar os riscos do desenvolvimento de LEMP nestes pacientes, e abordagens distintas (por vezes extremas) são empregadas para evitar o aparecimento dessa patologia. Atualmente, o grande desafio está em obter um equilíbrio entre os riscos e os benefícios do tratamento com Natalizumabe. Assim, é crucial desenvolver estratégias para monitorar pacientes portadores do vírus JC sob tratamento com Natalizumabe. A título de ilustração, pesquisamos o vírus no sangue e na urina de um paciente sob tratamento durante 12 meses. Também discutimos a eficácia dos métodos atualmente utilizados para avaliação de riscos e as implicações reais de reativação viral.

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.