Human herpesvirus 6 in hematolegic diseases in China

Background and Objectives. The prevalence and pathogenic role of human herp esvirus 6 (HHV-6) in various benign and malignant hematologic diseases rema in largely unknown. The aim of this study was to search for a possible invo lvement of HHV-6 in the pathogenesis of hematologic diseases. Design and Methods. The presence of HHV-6 DNA sequences was examined by pol ymerase chain reaction (PCR) in bone marrow mononuclear cells from 241 pati ents with benign and malignant hematologic diseases in China, Platelet-asso ciated immunoglobulin (PAlg) of 66 idiopathic thrombocytopenic purpura (ITP ) patients was measured by competitive enzyme-linked Immunosorbent assay. T he presence of HHV-6 DNA in sera from 31 ITP patients was examined by PCR, Paired serum samples from 19 ITP patients were analyzed for anti-HHV-6 IgG titers using an indirect immunofluorescence assay. Results. HHV-6 DNA was detected in 41% and 37.5% of ITP and acute leukemia patients respectively, but in only 6.7% of patients with iron deficiency an emia, HHV-6 positivity for ITP patients with excessive PAlgG was significan tly higher than in patients with a normal level of PAlgG, HHV-6 DNA was not detected in any of the serum samples from ITP patients. None of the 19 cas es of ITP showed a significant increase in anti-HHV-6 antibody titers durin g the convalescent phase compared with the onset phase. Interpretation and Conclusions. Our results indicate that HHV-6 infection m ight be associated with excessive PAlgG in some cases of ITP, and that the virus persists in a latent state. The pathogenic role of HHV-6 in ITP needs to be confirmed by further investigations. (C) 2000, Ferrata Storti Founda tion.