Pesquisa de bocavírus humano em pacientes submetidos a transplante alogênico de células progenitoras hematopoiéticas

• Autor(a) principal: Costa, Brunno Câmara Lopes
• Data de Publicação: 2018
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• dARK ID: ark:/38995/00130000061pb
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/8910
• topic: Bocavírus humano; Transplante alogênico de células progenitoras hematopoiéticas; Pacientes imunocomprometidos; Human bocavirus; Allogeneic hematopoietic stem cell transplantation; Immunocompromised patients; CIENCIAS BIOLOGICAS

Human Bocavirus (HBoVs) are classified in the Parvoviridae family and are associated with respiratory and gastrointestinal symptoms. Viral infections are an important cause of morbimortality in immunocompromised patients such as allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. The aim of the present study was to evaluate the positivity rate and loads of HBoVs in clinical samples (feces and sera) of patients who were subjected to allo-HSCT at a reference center for bone marrow transplantation in Goiânia, Goiás. A total of 105 fecal samples and 145 sera samples were collected from 21 consecutive patients, during October 2012 to October 2014. Samples were screened by qPCR TaqMan assay, with specific probe and primers targeting all HBoVs genotypes (HBoV-1 to -4), and viral loads were determined using serial dilutions of a recombinant plasmid, targeting the NP1 gene. The results showed that 53.4% (11/21) of the patients were male, aged between four and 61 years-old (mean 35 years). The most observed hematologic malignancy was myeloid leukemia (acute or chronic), accounting for 57.1% (12/21) of the cases. The HBoVs were detected in 42.9% (9/21) of the patients and 77.7% (7/9) were positive in both fecal and serum samples. The viral load in fecal samples were higher than in the sera samples and a prolonged fecal shedding were observed, with two patterns: one intermittent and another continuous. Of all HBoV positive patients, six (66.6%) had the first positive sample before the transplantation, and a rise of the viral loads after the allo-HSCT occurred when comparing to the loads before the allo-HSCT. Furthermore, on most cases the highest viral loads were detected during the first 100 days after the allo-HSCT. Considering the symptoms presented by the patients, 66.6% (6/9) had diarrhea at the same period of the viral genome detection in feces, but no statistical significance was observed. Three fecal samples were characterized as being HBoV-1, with more than 99% of nucleotide identity among them. The present data shows a high occurrence and loads of HBoVs in allo-HSCT recipients, with first positivity in fecal samples and later viral detection in sera. These results suggest that fecal samples could be the sample of choice in HBoV monitoring of these patients both before and after the transplant.