In this study, researchers from the United States sought to determine whether HCV quasispecies diversity correlated positively with liver disease progression, after orthotopic liver transplantation (OLT).
The team studied 11 patients undergoing OLT for HCV-related cirrhosis with recurrent hepatitis C.
Patients were divided into 2 groups, according to the stage of hepatic fibrosis on follow-up.
The mild group had stage 1 or 2 fibrosis, while the severe group had stage 3 or 4.
The researchers assessed HCV quasispecies diversity by cloning and sequencing in pre- and post-transplantation serum samples.
|Inverse correlation between the stage of hepatic fibrosis and amino acid complexity, following liver transplantation.|
They found that in the mild fibrosis group, intrasample hypervariable region 1 (HVR1) genetic distance and nonsynonymous substitutions increased after OLT.
Whereas in the severe fibrosis group, these parameters decreased in follow-up.
By contrast, intrasample diversity progressed similarly in both groups in the adjacent sequences flanking HVR1.
The team also identified an inverse correlation between the stage of hepatic fibrosis and amino acid complexity after OLT.
They found that among all patients, the estimated rate of amino acid change was greater initially and became more constant after 36 months.
Dr Andre Lyra's team concluded, "After OLT, a more complex HCV HVR1 quasispecies population was associated with mild disease recurrence".
"Among those patients with severe recurrent hepatitis C, HCV appeared to be under greater immune pressure".
"The greatest change in viral amino acid sequences occurred in the first 36 months after OLT".