Ultrastructural and physicochemical characterization of the hepatitis C virus recovered from the serum of an agammaglobulinemic patient.

Hepatitis C virus (HCV) morphology and physicochemical properties remain unclear because HCV usually circulates in a complexed form in association with immunoglobulins. In the present work, we were interested in the characterization of HCV particles derived from the serum of an anti-HCV negative/HCV RNA positive agammaglobulinemic patient suffering from chronic type C hepatitis. Physicochemical properties of the virus particles were determined by serum centrifugation on a 10-60% isopycnic sucrose density gradient. HCV RNA quantified by bDNA was found in a major peak at density 1.13 g/ml and in a minor peak at densities 1.05-1.07 g/ml. By electron microscopy, 45 nm large core-like particles were found at the 1.13 g/ml density while 60 nm large virus-like particles similar to other members of the Flaviviridae family were visualized at the 1.06-1.07 g/ml densities. This confirms some studies reporting the low density of HCV as compared to other members of the Flaviviridae family.