Esclerose múltipla e interação com os herpesvirus

Multiple sclerosis is the most common autoimmune inflammatory demyelinating disease of the central nervous system, and its etiology is believed to have both genetic and environmental components. Several viruses have already been implicated as triggers and there are several studies that implicate members of the Herpesviridae family in the pathogenesis of MS. The most important characteristic of these viruses is that they have periods of latency and exacerbations within their biological sanctuary, the central nervous system. The Epstein-Barr, cytomegalovirus, human herpesvirus 6 and human herpesvirus 7 viruses are the members that are most studied as being possible triggers of multiple sclerosis. According to evidence in the literature, the herpesvirus family is strongly involved in the pathogenesis of this disease, but it is unlikely that they are the only component responsible for its development. There are probably multiple triggers and more studies are necessary to investigate and define these interactions.A esclerose múltipla é a doença inflamatória auto-imune mais comum do sistema nervoso central. Sua etiologia já foi creditada apresentar tanto causas genéticas quanto ambientais. Vários vírus já foram implicados como desencadeadores desta doença e existem inúmeros trabalhos fazendo correlação entre a família Herpesviridae e a patogênese da esclerose múltipla. As características mais importantes dos Herpesviridae são as de apresentarem períodos de latência e exacerbação e terem como seu principal santuário biológico o sistema nervoso central. O vírus Epstein-Barr, o citomegalovírus, o herpesvirus tipo 6 e herpesvirus tipo 7 são os membros mais estudados como desencadeadores da esclerose múltipla. Conforme as evidencias que a literatura apresenta a família Herpesviridae está fortemente envolvida na patogênese da esclerose múltipla, porém é pouco provável que sejam os únicos responsáveis pelo seu início. É provável que esta doença apresente inúmeros desencadeadores e mais estudos são necessários para determinar estas interações

HERV-W/MRSV envelope transcripts detection\ud in blood of multiple sclerosis patients after\ud Natalizumab treatment

FAPESP 2010/10619-

BK virus salivary shedding and viremia in renal transplant recipients

Objectives: This study aimed to verify the presence of polyomavirus BK (BKPyV) in the saliva of kidney transplant recipients and to correlate it with blood viremia. Material and Methods: We have conducted a crosssectional study with a sample involving 126 renal transplant recipients. 126 samples of saliva and 52 samples of blood were collected from these patients. Detection and quantification of BKPyV were performed using a real-time PCR. To compare the presence of BKPyV in blood and saliva, the binomial proportion test was used. To verify associations between salivary shedding BKPyV and post-transplant periods (in months), the Mann-Whitney test was used. Spearman’s correlation was used to correlate the viral load in the saliva with blood of kidney transplant recipients. Results: The mean age of the study group was 51.11±12.45 years old, and 69 participants (54.8%) were female, with a mean post-transplantation time of 4.80±6.04 months. BKPyV was quantified in several samples of saliva and blood, with medians of 1,108 cp/mL and 1,255 cp/mL, respectively. Only 16/52 (30.8%) participants presented BKPyV in blood, and 59/126 (46.8%) excreted the virus in saliva (p=0.004). BKPyV shedding was found in patients at a shorter post-transplantation period (3.86±5.25, p=0.100). A weak correlation was observed between viral quantification in saliva and blood (Spearman’s correlation coefficient=0.193). Conclusion: The results of this study suggested that, although saliva excretes more BKPyV than blood, there is no reliable correlation between salivary shedding and blood viremia, showing two independent compartments of viral replication

Human polyomaviruses JC and BK in the urine\ud of Brazilian children and adolescents vertically infected by HIV

The aim of this study was to characterize the urinary excretion of the BK (BKV) and JC (JCV) human polyomavi\ud -\ud ruses in a cohort of human immunodeficiency virus (HIV)-infected children and adolescents. One hundred and fifty-\ud six patients were enrolled: Group I included 116 HIV-infected children and adolescents [median age = 11.4 years (y);\ud range 1-22 y]; Group II included 40 non-HIV-infected healthy controls (median age = 11.37 y; range 7-16 y). Single\ud urine samples from both groups were screened for the presence of JCV and BKV DNA by polymerase chain reaction\ud at enrolment. The overall rate of JCV and BKV urinary excretion was found to be 24.4% and 40.4%, respectively\ud (n = 156). Group I had urinary excretion of JCV and BKV in 27.6% and 54.3% of subjects, respectively. In contrast,\ud Group II showed positive results for JCV in 17.5% of subjects and for BKV in 12.5% of subjects (p Pearson JCV =\ud 0.20; p Pearson BKV < 0.0001). In Group I, there was no association between JCV/BKV shedding and age, gender\ud or CD4 values. Patients with an HIV viral load < 50 copies/mL had a lower excretion of BKV (p < 0.001) and a trend\ud of lower JCV excretion (p = 0.07). One patient in Group I (1/116, 0.9%) showed clinical and radiological features\ud consistent with progressive multifocal leukoencephalopathy, suggesting that children with HIV/polyomavirus coin\ud -\ud fection should be kept under surveillance.Financial support: FAPESP (07/06687-7

Community-acquired pneumonia in Chile: the clinical relevance in the detection of viruses and atypical bacteria

Background Adult community-acquired pneumonia (CAP) is a relevant worldwide cause of morbidity and mortality, however the aetiology often remains uncertain and the therapy is empirical. We applied conventional and molecular diagnostics to identify viruses and atypical bacteria associated with CAP in Chile.\ud \ud Methods We used sputum and blood cultures, IgG/IgM serology and molecular diagnostic techniques (PCR, reverse transcriptase PCR) for detection of classical and atypical bacteria (Mycoplasma pneumoniae, Chlamydia pneumoniae, Legionella pneumoniae) and respiratory viruses (adenovirus, respiratory syncytial virus (RSV), human metapneumovirus, influenza virus, parainfluenzavirus, rhinovirus, coronavirus) in adults >18 years old presenting with CAP in Santiago from February 2005 to September 2007. Severity was qualified at admission by Fine's pneumonia severity index.\ud \ud Results Overall detection in 356 enrolled adults were 92 (26%) cases of a single bacterial pathogen, 80 (22%) cases of a single viral pathogen, 60 (17%) cases with mixed bacterial and viral infection and 124 (35%) cases with no identified pathogen. Streptococcus pneumoniae and RSV were the most common bacterial and viral pathogens identified. Infectious agent detection by PCR provided greater sensitivity than conventional techniques. To our surprise, no relationship was observed between clinical severity and sole or coinfections.\ud \ud Conclusions The use of molecular diagnostics expanded the detection of viruses and atypical bacteria in adults with CAP, as unique or coinfections. Clinical severity and outcome were independent of the aetiological agents detected.This work was supported by the Fondo Nacional de Ciencia y Tecnología (FONDECYT) (grant number 1050734); and the Fondo Nacional de Investigación en Salud (FONIS) (grant number SA04 I 2084)

Detection of human polyomavirus JC in cerebrospinal fluid samples from aids patients with non-expansive focal lesions of CNS white matter

Doenças neurológicas focais em pacientes com aids podem ser causadas por vários patógenos oportunistas. Dentre estas se inclui a encefalite por Toxoplasma gondii, os linfomas primários do sistema nervoso central causados pelo vírus Epstein-Barr, as encefalites virais (CMV, HSV, VZV) e a leucoencefalopatia multifocal progressiva (LEMP), causada pelo vírus JC (VJC). O presente estudo teve por objetivos detectar o DNA do vírus JC em amostras de líquido cefalorraquidiano de pacientes com aids e lesões não expansivas de substância branca do SNC, bem como caracterizar esses pacientes com relação ao número de células TCD4+, sexo, idade e ocorrência de outros diagnósticos etiológicos. A detecção do DNA do VJC foi realizada através da técnica de reação em cadeia por polimerase. O protocolo de PCR empregado, anteriormente descrito, utiliza um par de primers complementar à região precoce do vírus JC (antígeno T), resultando em um fragmento de 173 pb. Todas as amostras positivas foram submetidas a etapa posterior de tipagem com enzima de restrição Bam H1, resultando em dois fragmentos menores (120 e 53 pb), característicos do vírus JC. Com o intuito de estimar a sensibilidade da técnica empregada, um controle positivo qüantificável foi padronizado. O fragmento de 173 pb amplificado de uma das amostras de líquor estudadas foi inserido em plasmídio, e o recombinante obtido foi quantificado através de espectrofotometria, titulado e submetido a PCR. Através desta metodologia foi possível estimar que o teste é capaz de detectar a partir de 200 cópias/ µl. A especificidade do teste foi avaliada através da análise de amostras de líquor de pacientes com e sem aids e outros diagnósticos neurológicos, não compatíveis com LEMP. A pesquisa do DNA do vírus JC foi negativa em 119 de 120 amostras testadas, demonstrando uma especificidade de 99,17%. Foram incluídas no estudo 56 amostras de líquor de pacientes com lesão focal não expansiva de substância branca, compatível com LEMP, sendo positiva em 27/56 (48,2%) e negativa em 29/56 (51,8%). Em 23 dos 29 (79,3%) pacientes negativos para o vírus JC foi possível estabelecer um diagnóstico diferencial para os quadros encefalíticos: Toxoplasma gondii (nove casos), complexo cognitivo motor do HIV (CCMHIV) (cinco casos), tuberculose (três casos) e outros diagnósticos (oito casos). Em seis pacientes DNA-VJC negativos não houve um diagnóstico final. A caracterização da população avaliada, dividida em dois grupos, de acordo com o resultado da PCR (DNA-VJC positivo ou DNA-VJC negativo), não demonstrou diferença estatisticamente significante no que diz respeito ao sexo ou idade. No grupo de pacientes DNA-VJC positivos, o número de células TCD4+ foi significativamente mais baixo. Os resultados do presente estudo demonstraram uma alta prevalência do DNA do VJC (48,2%) nesse grupo de pacientes. Foi possível concluir também que, em pacientes com aids e encefalite focal com lesões não expansivas de substância branca do sistema nervoso central, com PCR negativa para o VJC, é necessária uma investigação diagnóstica mais aprofundada já que a maioria desses casos apresenta outros agentes etiológicos, na maioria das vezes passíveis de tratamento.Focal neurological diseases in aids patients can be caused by a range of opportunistic pathogens such as Toxoplasma gondii, EBV-associated primary CNS lymphomas, viral encephalitis (CMV, HSV, VZV) and JC virus causing the progressive multifocal leukoencephalopathy (PML). In the present study, we evaluated the detection of JC virus DNA in CSF samples from aids patients with white matter non-expansive lesions of CNS by polymerase chain reaction (PCR) and characterize this finding in relation to the number of TCD4+, age, gender, and other etiological diagnosis. The primers used to amplify the T antigen region of JC virus resulted in a fragment of 173 base pairs. Since JC virus harbor a BAM H1 restriction site in this region, digestion of the PCR product with the enzyme resulted in two fragments of 120 and 53 base pairs, characteristic of JC virus. To estimate the sensitivity of the assay, the 173 bp fragment obtained from one of the samples was inserted into a plasmid and the recombinant quantified by spectrophotometry. The sensitivity of the PCR was 200 copies / µL. The specificity of the assay was evaluated in CSF samples from patients with and without aids and other neurological conditions, not suggestive of PML. The PCR resulted negative in 119 of the 120 CSF samples tested showing a specificity of 99,17%. In 56 CSF samples from patients with neurological symptoms and radiological signs of PML, JC virus was detected in 27 (48.2%) by PCR. In 23 of the remaining 29 patients (79.3%) other neurological conditions were diagnosed: T. gondii encephalitis (9 cases), HIV encephalitis (5 cases), tuberculosis (3 cases) and other diagnosis (8 cases). In six patients no neurological disease diagnosis could be established. In the group of patients characterized as JC virus-DNA positive the mean number of TCD4+ was significantly lower as compared to the JC virus-DNA negative patients. No statistical difference was seen in relation to gender or age distribution between the two groups. The results of the present study demonstrated a high prevalence of JC virus DNA (48,2%) in patients with clinical and radiological signs of PML. We concluded that the polymerase chain reaction for JC-virus DNA detection can represent an advance in the diagnosis of PML. aids patients with non-expansive focal lesions of CNS white matter and JC virus-DNA negative by PCR probably have other treatable neurological conditions that must be extensively investigated

Detection of human polyomavirus JC in cerebrospinal fluid samples from aids patients with non-expansive focal lesions of CNS white matter

Doenças neurológicas focais em pacientes com aids podem ser causadas por vários patógenos oportunistas. Dentre estas se inclui a encefalite por Toxoplasma gondii, os linfomas primários do sistema nervoso central causados pelo vírus Epstein-Barr, as encefalites virais (CMV, HSV, VZV) e a leucoencefalopatia multifocal progressiva (LEMP), causada pelo vírus JC (VJC). O presente estudo teve por objetivos detectar o DNA do vírus JC em amostras de líquido cefalorraquidiano de pacientes com aids e lesões não expansivas de substância branca do SNC, bem como caracterizar esses pacientes com relação ao número de células TCD4+, sexo, idade e ocorrência de outros diagnósticos etiológicos. A detecção do DNA do VJC foi realizada através da técnica de reação em cadeia por polimerase. O protocolo de PCR empregado, anteriormente descrito, utiliza um par de primers complementar à região precoce do vírus JC (antígeno T), resultando em um fragmento de 173 pb. Todas as amostras positivas foram submetidas a etapa posterior de tipagem com enzima de restrição Bam H1, resultando em dois fragmentos menores (120 e 53 pb), característicos do vírus JC. Com o intuito de estimar a sensibilidade da técnica empregada, um controle positivo qüantificável foi padronizado. O fragmento de 173 pb amplificado de uma das amostras de líquor estudadas foi inserido em plasmídio, e o recombinante obtido foi quantificado através de espectrofotometria, titulado e submetido a PCR. Através desta metodologia foi possível estimar que o teste é capaz de detectar a partir de 200 cópias/ µl. A especificidade do teste foi avaliada através da análise de amostras de líquor de pacientes com e sem aids e outros diagnósticos neurológicos, não compatíveis com LEMP. A pesquisa do DNA do vírus JC foi negativa em 119 de 120 amostras testadas, demonstrando uma especificidade de 99,17%. Foram incluídas no estudo 56 amostras de líquor de pacientes com lesão focal não expansiva de substância branca, compatível com LEMP, sendo positiva em 27/56 (48,2%) e negativa em 29/56 (51,8%). Em 23 dos 29 (79,3%) pacientes negativos para o vírus JC foi possível estabelecer um diagnóstico diferencial para os quadros encefalíticos: Toxoplasma gondii (nove casos), complexo cognitivo motor do HIV (CCMHIV) (cinco casos), tuberculose (três casos) e outros diagnósticos (oito casos). Em seis pacientes DNA-VJC negativos não houve um diagnóstico final. A caracterização da população avaliada, dividida em dois grupos, de acordo com o resultado da PCR (DNA-VJC positivo ou DNA-VJC negativo), não demonstrou diferença estatisticamente significante no que diz respeito ao sexo ou idade. No grupo de pacientes DNA-VJC positivos, o número de células TCD4+ foi significativamente mais baixo. Os resultados do presente estudo demonstraram uma alta prevalência do DNA do VJC (48,2%) nesse grupo de pacientes. Foi possível concluir também que, em pacientes com aids e encefalite focal com lesões não expansivas de substância branca do sistema nervoso central, com PCR negativa para o VJC, é necessária uma investigação diagnóstica mais aprofundada já que a maioria desses casos apresenta outros agentes etiológicos, na maioria das vezes passíveis de tratamento.Focal neurological diseases in aids patients can be caused by a range of opportunistic pathogens such as Toxoplasma gondii, EBV-associated primary CNS lymphomas, viral encephalitis (CMV, HSV, VZV) and JC virus causing the progressive multifocal leukoencephalopathy (PML). In the present study, we evaluated the detection of JC virus DNA in CSF samples from aids patients with white matter non-expansive lesions of CNS by polymerase chain reaction (PCR) and characterize this finding in relation to the number of TCD4+, age, gender, and other etiological diagnosis. The primers used to amplify the T antigen region of JC virus resulted in a fragment of 173 base pairs. Since JC virus harbor a BAM H1 restriction site in this region, digestion of the PCR product with the enzyme resulted in two fragments of 120 and 53 base pairs, characteristic of JC virus. To estimate the sensitivity of the assay, the 173 bp fragment obtained from one of the samples was inserted into a plasmid and the recombinant quantified by spectrophotometry. The sensitivity of the PCR was 200 copies / µL. The specificity of the assay was evaluated in CSF samples from patients with and without aids and other neurological conditions, not suggestive of PML. The PCR resulted negative in 119 of the 120 CSF samples tested showing a specificity of 99,17%. In 56 CSF samples from patients with neurological symptoms and radiological signs of PML, JC virus was detected in 27 (48.2%) by PCR. In 23 of the remaining 29 patients (79.3%) other neurological conditions were diagnosed: T. gondii encephalitis (9 cases), HIV encephalitis (5 cases), tuberculosis (3 cases) and other diagnosis (8 cases). In six patients no neurological disease diagnosis could be established. In the group of patients characterized as JC virus-DNA positive the mean number of TCD4+ was significantly lower as compared to the JC virus-DNA negative patients. No statistical difference was seen in relation to gender or age distribution between the two groups. The results of the present study demonstrated a high prevalence of JC virus DNA (48,2%) in patients with clinical and radiological signs of PML. We concluded that the polymerase chain reaction for JC-virus DNA detection can represent an advance in the diagnosis of PML. aids patients with non-expansive focal lesions of CNS white matter and JC virus-DNA negative by PCR probably have other treatable neurological conditions that must be extensively investigated