Direct infection of colony forming unit-megakaryocyte by human cytomegalovirus contributes the pathogenesis of idiopathic thrombocytopenic purpura.

Human cytomegalovirus (HCMV) late mRNA expression in megakaryoblast and in turn the pathogenesis of idiopathic thrombocytopenic purpura (ITP) patients with HCMV infection, and effectiveness of ganciclovir were investigated. Colony forming unit-megakaryocytes (CFU-MK) of 46 ITP patients with HCMV infection were incubated from patients' bone marrow mononuclear cells (MNC). Reverse transcriptase-polymerase chain reaction (RT-PCR) was subsequently used for CFU-MK for HCMV-late mRNA detection. Ganciclovir therapy was given to both HCMV-late mRNA positive and negative groups for comparison of therapeutic effectiveness. The results in 19 of 46 CFU-MK culture cells specimens with positive HCMV-DNA by PCR or positive CMV-IgM by enzyme linked immunosorbent assay (ELISA) in the correspondent serum of peripheral blood were positive for HCMV-late mRNA. Sixteen out of 19, patients with positive HCMV-late mRNA CFU-MK had a positive response to ganciclovir. Amongst 27 patients with negative HCMV-late mRNA CFU-MK, only 4 positive responders to ganciclovir therapy were observed. Curative effectiveness of ganciclovir in HCMV-late mRNA positive group was significantly higher than that in HCMV-late mRNA negative group (P<0.01). It was suggested that HCMV could directly infect CFU-MK, which might be one of the mechanisms responsible for HCMV related ITP. The ganciclovir is an effective therapy in resulting in the increases in thrombocyte in the ITP patients whose HCMV- late mRNA was positive in their CFU-MK.