Endogenous interferon-alpha level is increased in hepatitis C virus (HCV)-positive pregnant women

Mother-to-child transmission of hepatitis C virus (HCV) has been reported in around 5% of cases, and is much more likely to occur in case of coinfection with HIV. However, other cofactors influencing the vertical transmission are still debated.

To assess the serum concentration of endogenous interferon (IFN) during pregnancy, and its eventual role on the vertical transmission of HCV.

Forty-seven HCV-infected pregnant women, and 3 control groups: (1) 75 HCV-negative pregnant women; (2) 29 HCV-positive nonpregnant women; (3) 29 HCV-negative nonpregnant women entered into the study. Endogenous IFN was assayed by enzyme-linked immunosorbent assay. The following parameters were also analyzed: viral load, HIV infection, risk factors for acquiring HCV, parity, gestational age, mode and course of delivery.

Vertical transmission of HCV was observed in 2 cases (4.3%). Plasma levels of IFN were significantly higher in HCV-positive pregnant women compared with either HCV-positive and HCV-negative nonpregnant women. The 2 mothers who transmitted the infection had IFN levels within the same range as the women who did not transmit the infection.

In HCV-positive pregnant women, there is an increased production of endogenous IFN-alpha. Further studies are warranted for clarifying the mechanisms of this cytokine in the prevention of HCV transmission.