Cold activation of complement in sera from patients with persistent hepatitis C virus infection on interferon therapy

Changes in the acute phase complement component and IL-6 levels in patients with chronic hepatitis C receiving interferon alpha-2b

In order to study the effect of interferon alpha on the levels of acute phase complement proteins in vivo, serum concentrations of C9 and C1-inhibitor (C1-INH) were measured in patients with chronic hepatitis C before and 3 months after the beginning of interferon alpha2b therapy. Serum levels of the activation product of terminal complement pathway, C5b-9, HCV RNA and IL-6 were also determined. IFN alpha treatment significantly (P<0.0001) increased the serum concentrations of both complement proteins. C5b-9 levels were found to significantly decrease during the same period of time. When the patients were divided into responders or non-responders (more or less than 50% decrease in plasma HCV RNA concentrations) C9 and C1-INH levels were elevated only in the responder patients. There was no correlation between the changes of IL-6 levels or the amounts of IFN alpha administrated on one hand, and the changes in the complement protein levels on the other. These findings suggest that the marked increase in the serum concentrations of the acute phase complement proteins is a secondary phenomenon due to the IFN alpha-caused diminution of the viral load and the resulting immune complex-induced complement activation.

Loss of circulating hepatitis C virus in children who developed a persistent carrier state after mother-to-baby transmission

Of the 15 babies born to mothers infected with hepatitis C virus (HCV) and followed since birth, three developed HCV RNA in their serum. HCV RNA disappeared in two infants within 2 mo, but it persisted in the remaining infant. Mother-to-baby transmission was diagnosed retrospectively in an additional eight children aged 0.8-13.6 y. The eight children were followed for 1.4-5.0 y (mean +/- SD: 3.2 +/- 1.3 y) until they were 3.3-16.7 y old (8.5 +/- 4.3 y). Serum HCV RNA disappeared and antibodies to HCV decreased in the titer in two of the children when they were 3 y old. The spontaneous loss of serum HCV RNA was not observed in any of the other 14 children with posttransfusion infection who were followed for 2.6-6.1 y (4.0 +/- 1.1 y), until 3-22 y from the time they received transfusions and when they were 8.4-22.8 y old (15.4 +/- 4.1 y). These results indicate that the vertical transmission of HCV is rare, and some children can resolve the infection after a few years, whereas the infection persists in children who are infected by transfusion.

Antibodies to hepatitis C virus and elevated transaminase levels in a town of hyperendemicity in Iwate, Japan

In an annual survey for liver function tests in persons aged > 35 years in Iwate Prefecture, Japan, a town was identified where high levels of alanine aminotransferase abounded. Of 5152 inhabitants aged > 35 years in this town, antibodies to hepatitis C virus (HCV) determined by enzyme-linked immunosorbent assay with HCV core peptides were detected in 798 (15.5%) people, hepatitis B surface antigen was detected in 47 (0.9%) people and antibodies to hepatitis B surface antigen and/or hepatitis B core antigen unaccompanied by surface antigenaemia were detected in 1748 (33.9%) people. Antibodies to HCV core peptides correlated closely with the antibodies detected by passive haemagglutination with recombinant HCV proteins of the second generation. Antibodies to HCV core peptides were particularly common in one of the nine districts of the town (district 8), where 276 (45.3%) of 609 inhabitants tested positive; there were no differences in the frequency of serological markers of hepatitis B virus (HBV) infection among residents in the nine districts. Of the 798 individuals with antibodies to HCV core peptides, 257 (32.2%) were found to have elevated transaminase levels. A history of transfusion was associated with a high frequency of antibodies to HCV core peptides, except in district 8 where such antibodies were equally frequent in residents irrespective of transfusions. These results indicate an epidemiology of HCV distinct from that of HBV in this town and a very local spread of HCV, as well as a high frequency of hepatic injuries in individuals with antibodies to HCV.