Laboratório de Desenvolvimento Tecnológico em Virologia, Instituto Oswaldo Cruz, FIOCRUZ, Avenida Brasil, 4365, Manguinhos, Rio de Janeiro 21040-900, Brazil.
Departamento de Microbiologia e Parasitologia, Instituto Biomédico, Universidade Federal Fluminense, Niterói, Rio de Janeiro 24210-230, Brazil.
Viruses. 2022 Apr 18;14(4):843. doi: 10.3390/v14040843.
Low levels of parvovirus B19 (B19V) DNA can be detected in the circulation and in different tissue of immunocompetent individuals for months or years, which has been linked to inflammatory diseases such as cardiomyopathy, rheumatoid arthritis, hepatitis, and vasculitis. However, the detection of B19V DNA does not necessarily imply that infectious virions are present. This study aimed to evaluate the method based on the Benzonase treatment for differentiation between the infectious virions from "naked" DNA in serum and bone marrow (BM) samples to be useful for the B19V routine diagnosis. In addition, we estimated the period of viremia and DNAemia in the sera and bone marrow of nonhuman primates experimentally infected with B19V. Serum samples from ten patients and from four cynomolgus monkeys experimentally infected with B19V followed up for 60 days were used. Most of the human serum samples became negative after pretreatment; however, only decreased viral DNA loads were observed in four patients, indicating that these samples still contained the infectious virus. Reduced B19V DNA levels were observed in animals since 7th dpi. At approximately 45th dpi, B19V DNA levels were below 10 IU/mL after Benzonase pretreatment, which was not a consequence of active B19V replication. The test based on Benzonase pretreatment enabled the discrimination of "naked DNA" from B19V DNA encapsidated in virions. Therefore, this test can be used to clarify the role of B19V as an etiological agent associated with atypical clinical manifestations.
低水平的微小病毒 B19（B19V）DNA 可在免疫功能正常个体的循环和不同组织中检测到数月或数年，这与心肌病、类风湿性关节炎、肝炎和血管炎等炎症性疾病有关。然而，B19V DNA 的检测并不一定意味着存在感染性病毒颗粒。本研究旨在评估基于苯甲酸钠处理的方法，用于区分血清和骨髓（BM）样本中的感染性病毒颗粒与“裸露”DNA，以用于 B19V 的常规诊断。此外，我们估计了非人类灵长类动物实验感染 B19V 后的病毒血症和 DNA 血症期。使用了来自 10 名患者和 4 只实验感染 B19V 的食蟹猴的血清样本进行研究。10 名人类患者的血清样本经预处理后大部分呈阴性；然而，只有 4 名患者的病毒 DNA 载量下降，表明这些样本仍含有感染性病毒。自第 7 天感染后，动物的 B19V DNA 水平降低。在大约第 45 天，B19V DNA 水平在苯甲酸钠预处理后低于 10 IU/mL，这不是 B19V 复制活跃的结果。基于苯甲酸钠预处理的检测能够区分“裸露 DNA”和包裹在病毒颗粒中的 B19V DNA。因此，该检测可用于阐明 B19V 作为与非典型临床表现相关的病因的作用。
