Background/Aims: Hepatitis C virus (HCV) infection is common in liver
transplant recipients, yet the effects of immunosuppression on HCV RNA
levels and the relationship of HCV RNA levels to hepatic damage have
not been studied. Methods: To explore these issues, we measured HCV RN
A in serum by polymerase chain reaction amplification and branched DNA
assay from 100 HCV-infected patients undergoing liver transplantation
. Results: Mean posttransplant levels were 16-fold higher than pretran
splant values (7,935,000 and 496,000 Eq/mL, respectively; n = 65; P <
0.0001). Patients with high pretransplant levels had higher mean postt
ransplant levels than those with low pretransplant levels (17,119,000
and 6,504,000 Eq/mL, respectively; P = 0.064). Posttransplant levels w
ere similar in patients with recurrent and acquired infection and were
independent of time of sampling. Fifty percent of patients with HCV i
nfection had normal liver biopsy specimens, and there was no strong re
lationship between level of viremia and degree of hepatic damage. Conc
lusions: HCV RNA levels increase markedly following liver transplantat
ion. The frequent finding of viremia in the absence of histological he
patitis suggests that a ''carrier state'' is common. Absence of allogr
aft damage in some (despite high levels of viral RNA) suggests that in
immunosuppressed patients, HCV infection may be tolerated without dir
ect hepatic damage.