Avaliação da infecção por Parvovírus Humano B19 em diferentes grupos populacionais: diagnóstico diferencial e aspectos imunopatogênicos da infecção aguda e persistente / Evaluation of Human Parvovirus B19 infection in different population groups: differential diagnosis and immunopathogenic aspects of acute and persistent infection

A infecção pelo Parvovírus B19 (B19V) pode ocorrer em indivíduos imunocompetentes e imunocomprometidos, de todas as faixas etárias, e se caracteriza por ser aguda e autolimitada, podendo levar a quadros de doença exantemática (DE), doença febril aguda (DFA), doença renal crônica (DRC) e falência hepática aguda (FHA). O diagnóstico diferencial de B19V nessas populações, muitas vezes, não ocorre e estudos sobre a prevalência do B19V são antigos e escassos, não refletindo a atualidade. Marcadores da infecção podem ser detectados na circulação e em diferentes tipos de tecidos, inclusive em tecidos não eritroides, por meses ou anos. A infecção pode levar a manifestações clínicas graves, que requer tratamento hospitalar, e a doenças inflamatórias atípicas, como: cardiomiopatia, artrite reumatoide, hepatite e vasculite. No entanto, a detecção de B19V DNA não implica necessariamente na presença de vírions infecciosos e na associação do B19V com essas manifestações atípicas. Dessa forma, o objetivo do trabalho foi otimizar técnicas de PCR em tempo real para quantificação do B19V DNA e de detecção de partículas virais infecciosas, a fim de realizar o diagnóstico diferencial da infecção pelo B19V em pacientes com DE, DFA, DRC e FHA. Para o diagnóstico da infecção, amostras de diferentes populações foram testadas: DE (n=54), DFA (n=60), DRC (n=221), e FHA (n=30). Amostras de soro (e de tecido hepático para FHA) foram submetidas a avaliação de marcadores sorológicos (IgM e IgG anti-B19V) e moleculares do B19V, a fim de determinar a fase da infecção em que o paciente se encontrava. Para a avaliação de marcadores moleculares, a metodologia de PCR quantitativo e em tempo real foi otimizada e permitiu um diagnóstico sensível e específico do B19V DNA. Além disso, a presença de vírions em amostras de pacientes com B19V (n=10) e de macacos cynomolgus (n=4) infectados experimentalmente foram avaliadas por meio da técnica de pré-tratamento das amostras com uma enzima endonuclease. O teste molecular (qPCR) otimizado durante o estudo, apresentou sensibilidade e especificidade de 100%. O ensaio com a endonuclease revelou que a maioria das amostras de soro humano tornou-se B19V DNA negativa após o pré-tratamento, indicando que não eram infecciosas. Foi observado prevalências do B19V DNA em 5,5% dos pacientes com DE; 6,6% em DFA; 65,6% em DRC, e 23,3% em FHA. Como conclusão a técnica de qPCR otimizada no presente estudo foi efetiva para o esclarecimento de casos da infecção por B19V e é adequada para diagnóstico diferencial. Além disso, o teste laboratorial baseado em endonuclease possibilitou a discriminação do B19V DNA (se encapsidado em vírions ou não). Portanto, estes testes podem ser utilizados para esclarecer o papel do B19V como agente etiológico associado a diversas manifestações clínicas. As prevalências encontradas nesse estudo indicam que o B19V está circulando entre os diversos grupos populacionais estudados e deve ser feita uma melhor vigilância da infecção, pois está presente tanto em indivíduos imunocompetentes como em imunocomprometidos. Além disso, os resultados sugerem a importância da inclusão de B19V no diagnóstico laboratorial diferencial, não apenas para fins epidemiológicos, mas também para o manejo adequado do paciente.

Parvovirus B19 (B19V) infection can occur in immunocompetent and immunocompromised individuals of all group ages and is characterized as acute and self limiting, which can lead to rash disease (RD), acute febrile illness (AFI), chronic kidney disease (CKD), and acute liver failure (ALF). Differential diagnosis of B19V in these populations often does not occur and studies on the prevalence of B19V are scarce, outdated, and do not reflect the current situation. B19V markers of acute infection can be detected in the circulation and in different tissue types, including non-erythroid tissues, for months to years and may lead to severe clinical manifestations, requiring hospital treatment, and to atypical inflammatory diseases, such as cardiomyopathy, rheumatoid arthritis, hepatitis, and vasculitis. However, the detection of B19V DNA does not necessarily imply the presence of infectious virions and the causal relation between B19V and atypical manifestations could not be proved yet. Thus, the aim of this study was to standardize the real-time PCR for quantification of B19V DNA and detection of infectious viral particles in order to perform the differential diagnosis of the B19V infection in RD, AFI, CKD, and ALF patients. For the diagnosis of the infection, samples from different populations were tested: RD (n=54), AFI (n=60), CKD (n=221), and ALF (n=30). Serum samples (and hepatic tissue for ALF) were submitted to the evaluation of B19V serological status (anti-B19V IgM and IgG antibodies) and molecular markers, in order to determine the stage of infection in which the patient is. For the evaluation of molecular markers, a quantitative real-time PCR methodology was optimized and allowed a sensitive and specific diagnosis of B19V DNA. In addition, the presence of virions in samples from patients with B19V (n=10) and from cynomolgus monkeys (n=4) experimentally infected were evaluated by endonuclease enzyme pretreatment. The molecular test optimized during the study showed 100% sensitivity and specificity. The endonuclease treatment assay revealed that most human serum samples became negative after pretreatment, as indicative of non-infective particles. Concerning the prevalence of B19V DNA: 5.5% were obtained in patients with RD; 6.6% in AFI; 65.6% in CKD, and 23.3% in ALF. In conclusion, the qPCR technique optimized in the present study was effective for clarifying cases of B19V infection and is suitable for differential diagnosis. In addition, the endonuclease-based laboratory test made it possible to discriminate B19V DNA (whether encapsidated in virions or not). Therefore, these tests can be used to clarify the role of B19V as an etiologic agent associated with several clinical manifestations. The prevalence found in this study indicate that B19V is circulating among the different populational groups that have been studied and better surveillance of the infection should be carried out, as it is present in both immunocompetent and immunocompromised individuals. In addition, the results suggest the importance of including B19V in the differential laboratory diagnosis, not only for epidemiological purposes but also for the proper management of the patient.

Aplasia pura de células rojas secundaria a infección por parvovirus B19 en paciente VIH positivo / Pure red cell aplasia secondary to parvovirus B19 infection in an HIV positive patient

Resumen La infección crónica por parvovirus B19 en pacientes seropositivos para el virus de inmunodeficiencia humana (VIH) es una causa identificable y tratable de anemia en esta población, que en nuestro medio aún no ha sido muy estudiada. La búsqueda activa de este patógeno en pacientes VIH positivos con anemia grave sin compromiso de otras líneas celulares puede llevar a una mejoría en la calidad de vida en el tiempo y reducción de los costos de la enfermedad para el sistema de salud. Nosotros presentamos el caso de un paciente con síndrome de inmunodeficiencia adquirida y anemia a quien se le identifico parvovirus B19. (Acta Med Colomb 2018; 43: 42-44).

Abstract The chronic infection by parvovirus B19 in seropositive patients for the human immunodeficiency virus (HIV) is an identifiable and treatable cause of anemia in this population, which in our environment has not yet been widely studied. The active search for this pathogen in HIV positive patients with severe anemia without compromising other cell lines can lead to an improvement in the quality of life over time and reduction of the costs of the disease to the health system. We present the case of a patient with acquired immunodeficiency syndrome and anemia who was identified as parvovirus B19. (Acta Med Colomb 2018; 43: 42-44).

Genotype 1 of human parvovirus B19 in clinical cases / Genótipo 1 do parvovírus humano em casos clínicos

Summary Introduction: Virus surveillance strategies and genetic characterization of human parvovirus B19 (B19V) are important tools for regional and global control of viral outbreak. In São Paulo, Brazil, we performed a study of B19V by monitoring the spread of this virus, which is an infectious agent and could be mistakenly reported as a rash and other types of infection. Method: Serum samples were subjected to enzyme immunoassay, real time polymerase chain reaction, and sequencing. Results: From the 462 patients with suspected cases of exanthematic infections, the results of the 164 serum samples were positive for B19V immunoglobulin M. Among these cases, there were 38 patients with erythema infections and B19-associated with other infections such as encephalitis, hydrops fetalis, chronic anemia, hematological malignancies. These samples were sequenced and identified as genotype 1. Conclusion: This study showed patients with infections caused by B19V and sequencing genotype 1. Continuous monitoring is necessary to detect all known genotypes, and the emergence of new genotypes of these viruses for case management in public health control activities.

Resumo Introdução: Estratégias de vigilância para o parvovírus humano B19 e caracterização genética são ferramentas importantes para o controle regional e global do surto viral. Em São Paulo, Brasil, foi realizado um estudo de parvovírus B19, monitorando a disseminação desse vírus, que é um agente infeccioso e poderia ser erroneamente relatado como uma erupção cutânea e outros tipos de infecções. Método: As amostras de soro foram submetidas ao ensaio imunoenzimático, PCR quantitativo em tempo real e sequenciamento. Resultados: Dos 462 pacientes com casos suspeitos de infecções exantemáticas, os resultados das 164 amostras de soro foram positivos para parvovírus B19 imunoglobulina M. Entre eles, 38 pacientes com eritema infeccioso apresentaram B19 associado com outras infecções, como encefalite, hidropisia fetal, anemia crônica, doenças hematológicas malignas. Essas amostras foram sequenciadas e identificadas como genótipo 1. Conclusão: Os pacientes foram infectados com parvovírus B19 e apresentaram genótipo 1. Monitoração contínua é necessária para detectar todos os genótipos conhecidos e o surgimento de novos genótipos para o controle de casos em saúde pública.

Study of chronic hemolytic anaemia patients in Rio de Janeiro: prevalence of anti-human parvovirus B19 IgG antibodies and the developement of transient aplastic crises

The prevalence of anti-human parvovirus B19 IgG antibodies was determined in sera from 165 chronic hemolytic anemia patients, receiving medical care at Instituto Estadual de Hematologia (IEHE), Rio de Janeiro, during the year of 1994. This sample represents around 10 percent of the chronic hemolytic anemia patients attending at IEHE. Most of these patients (140) have sickle cell disease. Anti-B19 IgG antibodies were detected in 32.1 percent of patients. No statistically significant difference (p > 0.05) was seen between IgG antibody prevalence in male (27.8 percent) and female (35.5 percent) patients. Anti-B19 IgG antibodies were more frequent in older (37.6 percent) than younger (28.2 percent) than 20 years old patients, although this difference had no statistical significance (p > 0.05). Anti-B19 IgG antibody prevalence showed that 67.9 percent of patients enrolled in the study were susceptible to B19 acute infection. With the aim to detect acute B19 infection, patients follow up continued until February 1996. During this period four patients presented transient aplastic crisis due to human parvovirus B19 as confirmed by the detection of specific IgM antibodies. All four patients were younger than 20 years old, and 3 were younger than 10 years old. Three of them were sickle cell disease patients. Three of the four acute B19 infection occurred during 1994 springtime

Detection of human parvovirus B19 in a patient with hepatitis

Parvovirus B19 has been associated by some investigators with cases of severe hepatitis. The aim of the present study was to determine the presence of active parvovirus B19 infection among 129 Brazilian patients with non-A-E hepatitis. The patients were assayed for antibodies against parvovirus B19, IgM class, by ELISA. In IgM-positive cases, parvovirus B19 DNA was assayed by PCR in serum and liver tissue and parvovirus VP1 antigen in liver tissue was assayed by immunohistochemistry. Antibodies against parvovirus B19, IgM class, were detected in 3 (2.3 percent) of 129 patients with non-A-E hepatitis. Previous surgery and blood transfusions were reported by these 3 patients. One patient was a 56-year-old female with severe hepatitis, with antimitochondrial antibody seropositivity and submassive necrosis at liver biopsy, who responded to corticosteroid therapy. Strong evidence for active parvovirus B19 infection was found in this patient, with parvovirus B19 DNA being detected by PCR in liver tissue. Furthermore, parvovirus VP1 antigen was also detected in liver tissue by immunohistochemistry. The other two IgM-positive patients were chronic hepatitis cases, but active infection was not proven, since neither viral DNA nor antigen were detected in their liver tissues. This and other reports suggest a possible relation between parvovirus B19 infection and some cases of hepatitis

Granulomatosis de Wegener: a propósito de un caso / Wegener's granulomatosis: case report

La granulomatosis de Wegener se caracteriza por la presencia de lesiones granulomatosas necrosantes de vías áereas, glomerulonefritis y con frecuencia, vasculitis que afecta a otros órganos. Presentamos una paciente con granulomatosis de Wegener y comentamos la clínica, patogenia, diagnóstico y tratamiento de dicha enfermedad

Manifestações reumáticas associadas à parvovirose / Rheumatic manifestations associated with parvovirus infection

O parvovírus B19 pode levar a diferentes quadros clínicos nos pacientes por ele infectados. Ainda que a maioria dos casos apresente-se assintomática ou oligossintomática, o espectro do acometimento clínico inclui a hidropsia fetal, o eritema infeccioso, crises aplásicas em pacientes com anemia hemolítica e anemia crônica naqueles imunodeprimidos, além de artropatia. Esta geralmente é autolimitada, porém vêm sendo descritos quadros que evoluem para cronicidade. Mais recentemente, tem sido estudado o papel do parvovírus B19 na gênese de várias enfermidades reumáticas, como a artrite reumatóide (do adulto e juvenil), o lúpus eritematoso sistêmico, algumas vasculites e fibromialgia. É pois, a infecção pelo parvovírus B19,assunto extremamente importante para o reumatologista, devendo tal infecção ser lembrada e pesquisada por intermédio de sorologia apropriada.