Essential mixed cryoglobulinemia is frequently associated with hepatitis C virus (HCV) infection. A beneficial effect of interferon alfa therapy has been reported, but we do not know whether the antiviral activity of the drug affects the clinical and biochemical manifestations of disease.

We studied the perinatal transmission of hepatitis C virus (HCV) in 70 high risk mother/infant pairs. Seventy-six percent of the mothers (53 of 70) were coinfected with human immunodeficiency virus (HIV) and 79% (55 of 70) had a history of drug addiction. During the follow-up HCV RNA was detected in 14 of 70 (20%) infants: 12% (2 of 17) in infants born to HIV-negative mothers; and 23% (12 of 53) in infants to HIV-positive mothers. The rate of vertical transmission was significantly higher in vaginally delivered infants than in those delivered by cesarean section (32% vs. 6%; P < 0.05). All 56 uninfected infants lost passively acquired anti-HCV by age 9 +/- 4 months and only 2 of 56 infants (4%) had evidence of HIV infection. Four of 14 HCV RNA-positive infants (29%) had evidence of HIV coinfection. We observed 3 clinical patterns of HCV infection: a transient viremia in 2 infants; an acute pattern in 2 infants; and a chronic pattern in 10 infants. All 4 HIV-coinfected infants had chronic HCV infection. All infants with a chronic pattern, had increased alanine aminotransferase values for more than 6 months and 5 had a liver biopsy that showed signs of chronic persistent hepatitis. HCV perinatal transmission was more frequent in infants born to HIV-coinfected mothers than in infants born to HIV-noninfected women, particularly when delivered vaginally.

Controversial data were recently published concerning the association of hepatitis B virus (HBV) variants with fulminant hepatitis (FH). In this study, we first analyzed the complete nucleotide sequences of HBV genomes isolated from serum samples from a surgeon and his mother, who was accidentally infected by the son; both died of FH. The infecting viruses were genetically almost identical in both patients; all the clones examined carried a double nucleotide mutation in the start codon of the pre-S2 region that prevented the synthesis of the corresponding protein. Analyses of different serum samples from the son revealed only wild-type precore sequences in a high viremic serum, whereas hepatitis B e antigen (HBeAg)-defective strains were prevalent when the viremia had decreased. Subsequently, we extended the analysis to the viral genomes isolated from 18 additional patients with acute HBV infection and different clinical behaviors: 3 of 5 patients with FH and without previous liver disease had pre-S2 start codon mutations preventing pre-S2 protein synthesis, whereas none of the 13 control cases had similar genomic rearrangements. Analysis of the precore region showed that viral populations normally producing HBeAg were the only or the prevalent viral strains in all of these cases. In summary, our results support the hypothesis that the pre-S2 protein is not essential for HBV infectivity. They also show that infection by pre-S2-defective virus is frequently associated with FH, indicating that this variant might play a pathogenetic role in cases of acute liver failure. Finally, they suggest that the emergence of HBeAg-defective viruses might be a late event in the course of FH, occurring when HBeAg-producing viruses have been mostly cleared.