Study on the Parvovirus B19 in its related diseases and DNA Sequence Variation of Parvovirus B19

• Main Authors: Liu Yun Ru, 劉韻如
• Other Authors: 林亮音
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/50280902560059627951

碩士 === 國立臺灣大學 === 醫事技術學研究所 === 88 === Human parvovirus B19, which is small and nonenveloped, contains a linear single-stranded DNA genome. The DNA genome encodes one nonstructural protein, NS-1 and two viral capsid proteins, VP1 and VP2. B19 is the only known human pathogenic parvovirus, and is transmitted by aerosol via the respiratory tract, contact exposure, placenta and blood transfusion. Erythroid progenitor cells are the targets of parvovirus B19 via blood group P antigen. Erythroid P antigen is abundant on the red blood surface, and the P antigen is also found on megakaryocyte, endothelial cell, some placental cells, as well as fetal liver and heart. Because of the broad cells affected and the renewable nature of the erythroid progenitor target cell population, it resulted in various clinical manifestations including thrombocytopenia, hydrops fetalis, hepatitis and myocarditis. B19 parvovirus can persist in cancer patients receiving systemic chemotherapy and then causes chronic transfusion-dependent anemia, accompanying with severe neutropenia sometimes. The hemophilia patients continuously receive cryoprecipitate and factor concentrates, we suggested that these patients should be prevalent in parvovirus B19. In this study, blood samples from the patients with various cancers, hemophilia, SLE, and myocarditis were collected for IgG determination with ELISA method and viral DNA detection with nested PCR method. The overall prevalence of anti-B19 IgG in young patients receiving multiple courses of systemic chemotherapy and hemophilia were 48.72% and 91.28%, respectively, and higher than the prevalence in healthy blood donors. The overall parvovirus B19 DNA seropositive rates in hemophilia and healthy blood donors were 6.71% and 0.41%, respectively. Therefore, it should be indicated to screen the existence of B19 DNA in blood product before transfusing to hemophilia patients. Because parvovirus B19 can''t be propagated in general cell lines, we utilize PCR and nucleotide sequencing to evaluate the variance of various B19 strains. These techniques could help us to realize the outbreak and transmission of B19, and to develop new molecular detecting method and vaccines. In this study, we also analyzed the difference among various B19 strains from our patients and Genebank. We found that there were a few nucleotide substitutions among those B19 strains from our patients. Furthermore, comparing to the B19 sequence from Genebank, there was substantial differences in the B19 stains from our patients.