THE INCIDENCE AND NATURAL COURSE OF A TRANSFUSION-ASSOCIATED GB VIRUS-C HEPATITIS-G VIRUS-INFECTION IN A COHORT OF THALASSEMIC PATIENTS/

To evaluate the risk of transmitting blood-borne GB virus C/hepatitis G virus (GBV-C/HGV) and to define the natural course of infection, we performed a prospective study in a cohort of multitransfused P-thalass emics during a B-year follow-up period. We analyzed serum samples of 1 50 patients collected at 8-year intervals from 1990 to 1996. GBV-C/HGV RNA was determined by reverse transcriptase-polymerase chain reaction and antibodies to ES-protein by an enzyme immunoassay. At baseline, 1 4.5% of patients had viremia and 18.5% anti-E2. None of the patients w ith anti-E2 in 1990 subsequently became viremic. Of the 100 GBV-C/HGV RNA(-), anti-E2(-) patients, 10 acquired infection during follow-up, a s indicated by positivity of GBV-C/HGV RNA (n = 2), anti-E2 (n = 7), o r both markers (n = 1) in 1996. The incidence was 1.7 per 100 person-y ears (95% confidence interval [CI], 0.8 to 3). Since approximately 19, 000 blood units were transfused to these patients during follow-up, th e risk of infection was 5.3 in 10,000 units (95% CI, 2 to 8.5). Six of 22 viremic patients cleared the virus during follow-up; 4 of them bec ame anti-E2(+). Twelve of 28 patients lost anti-E2 reactivity during f ollow-up. In conclusion, more than 25% of infections resolve within 6 years; the presence of anti-E2 seems to be protective against infectio n. Anti-E2 reactivity may decrease with time. (C) 1998 by The American Society of Hematology.