Aplastic anemia and hepatitis C: Molecular biology exonerates another suspect

Objective. - To test the hypothesis that the rare, often fatal, syndrome of hepatitis-associated aplasia is associated with hepatitis C virus infection. Design. - Case series. Setting.-Tertiary referral centers in the United States, Japan, Italy, and Germany. Patients. - Twenty-eight patients with onset of aplastic anemia within 90 days after seeking medical attention for jaundice, or having serum transaminase levels 150% or more of normal (hepatitis-associated aplasia patients) and three patients who developed aplastic anemia following liver transplantation for non-A, non-B, hepatitis. Outcome Measures. - Presence of hepatitis C in serum, bone marrow, and liver samples, detected by the polymerase chain reaction; antibody testing; and percentage of activated peripheral cytotoxic T lymphocytes determined by immunophenotyping. Results. - Hepatitis ribonucleic acid was present in the serum samples of 10 (36%) patients with hepatitis-associated aplasia. However, hepatitic C virus viremia was associated with transfusions received after the onset of aplasia: seven (58%) of 12 patients with hepatitis-associated aplasia who had received 21 or more units of blood products at the time of serum sampling were viremic, compared with only three (19%) of 16 patients with hepatitis-associated aplasia who had received 20 or less units of blood products (P <.05). Hepatitis C virus was not found in blood and bone marrow samples of three National Institutes of Health case patients tested at the time of diagnosis. None of three livers from non-A, non-B hepatitis patients who developed aplastic anemia after liver transplantation contained hepatitis C virus ribonucleic acid. Activated CD8+ T lymphocytes were elevated three- to 20-fold early in the course of hepatitis-associated aplasia. Conclusions. - Our results implicate a novel, non-A, non-B, and non-C agent in both hepatitis-associated aplasia and fulminant hepatitis.