The origin of hepatitis C virus reinfecting transplanted livers: serum-derived versus peripheral blood mononuclear cell-derived virus.

When hepatitis C virus (HCV) infection recurs after liver transplantation, it is unclear whether the liver graft is colonized by virions present in the circulation or by those associated with peripheral blood mononuclear cells (PBMC). In 6 HCV-infected transplant recipients, HCV sequences were analyzed by the single-strand conformational polymorphism (SSCP) assay and direct sequencing in pretransplant-paired PBMC and serum samples and in posttransplant follow-up serum samples. In 2 patients, SSCP patterns for pretransplant PBMC-serum pairs were identical, while in 4 patients they were different. In 3 patients from the latter group, the posttransplant viral sequences resembled those found in pretransplant serum samples, whereas in the other patient from that group, viral sequences after transplantation were transiently identical to those found in pretransplant PBMC. In HCV-positive liver transplant recipients, the liver graft is colonized primarily by liver-derived virus remaining in the circulation. However, virus variants of likely extrahepatic origin can be detected in serum early after transplantation.