Identification and visualization of virus-like particles in peripheral blood mononuclear cells]

OBJECTIVE: PBMCs from patients with chronic hepatitis C were examined by electron microscopy (EM), immune EM (IEM) combined with immunohistochemistry to trace the infection and morphology of HCV in the PBMCs. METHODS: The PBMCs from 28 patients with chronic hepatitis C were analyzed firstly for HCV RNA and HCV antigens by RT-PCR and immunohistochemistry respectively. The PBMCs with positive HCV RNA and HCV antigens were then observed by electron microscopy. RESULTS: The positive rate of HCV RNA and HCV antigens were 77.27% (17/22) and 75.00% (21/28), respectively. Two types of polymorphic HCV-like particles with diameter of approximately 65 nm and 110 nm were observed in cytoplasmic vesicles of the PBMCs from HCV Ag positive patients. 10 patients with HCV Ag over expression were studied by electron microscopy and immune election microscopy. The budding phenomenon of the particles could be also visualized in the cytoplasmic vesicles of the PBMCs. Some ultrastructural changes showed an increased ratio of cytoplasm to nucleus and pyknosis of nucleus was also suggestive of the virus infection. CONCLUSIONS: The EM study demonstrated the infection and replication of HCV in the PBMCs of chronic hepatitis C patients by morphology and morphogenesis.