Does Coinfection with HIV Facilitate Mother-to-child and Female-to-male Transmission of HCV?
By Ronald Baker, PhD

Fifty to 90% of HIV positive individuals are reportedly coinfected with hepatitis C virus (HCV), depending on the risk group being described [1]. It is well established that HIV coinfection accelerates the progression of HCV disease. In addition, there are data to suggest that HCV coinfection accelerates the progression of HIV disease [2,3], although the study results are conflicting.

Although there is ample evidence supporting the conclusion that injection drug use is the primary mode of transmission of HCV, the cause of greater than 20% of new HCV infections cannot be accounted for [4,5].

There are some reports that sexual intercourse may transmit HCV [4, 6,7], as well as childbirth [8,9], and even casual contact among members of the same household [10]. Interestingly, HIV coinfection with HCV appears to increase the possibility of mother-to-child and female-to-male transmission of HCV. [9]. However, the evidence supporting female-to-male transmission of HCV is scant [11,12].

There are also some data suggesting that HCV replication may be directly enhanced by the presence of HIV-1 [13]. Very few studies have assessed the presence of HCV RNA in vaginal secretions.

The purpose of the current study was to analyze the presence of HCV RNA in cervicovaginal lavage (CVL) fluid from 71 women enrolled in the Women's Interagency HIV Study. Results of the study, conducted at 3 medical centers, appear in the November 1, 2005 issue of the Journal of Infectious Diseases [14].

Results

Fifty-eight of the women were HCV-HIV coinfected and 13 had HCV monoinfection.

HCV RNA was detected (by a commercial polymerase chain reaction assay) in CVL fluid from 18 (29%) of the HIV-1-infected women and from none of the HIV-1-uninfected women (P < .05).

Multivariate analysis revealed that risk factors for the presence of HCV RNA in CVL fluid were HCV viremia and HIV-1 RNA in CVL fluid.

This observation suggests local interactions between HIV-1 and HCV in the genital tract compartment.

There was no correlation between HCV RNA in CVL fluid and CD4, CD8, or CD3 cell counts, HIV-1 RNA viremia, the number of leukocytes in CVL fluid, or HIV-1 therapy.

Furthermore, in 3 of 5 analyzed patients who had a detectable CVL HCV RNA load, the researchers found viral variants differing in the 5 untranslated region that were present neither in plasma nor in peripheral-blood mononuclear cells.

Discussion

“To our knowledge, our study is the first to demonstrate compartmentalization of HCV in the genital tracts of HCV-HIV-1 coinfected women and possible local replication in a large proportion of HCV-HIV-1 coinfected women,” write the authors.

Further, they note, “We found unique but related viral variants in the blood and genital tract compartments, suggesting that HCV may replicate locally in cells shed from the genital tract.”

These findings have important implications for both sexual and perinatal transmission of HCV.

“Findings from our study,” write the authors, suggest that ^“a local HCV genital tract reservoir may exist and that this may be the source of infection for those suspected to have been infected sexually.”

The mechanism by which local HIV-1 facilitates the presence of HCV in the genital tract remains unclear.

In conclusion, the authors state, “We have found that HCV RNA can be detected in almost 30% of HCV-HIV-1 coinfected women and that viral diversity does exist between local HCV and plasma HCV extracted from HCV-HIV-1 coinfected women.”

“Our findings may explain a comparatively higher rate of HCV vertical transmission by HIV-1coinfected women reported in several studies. The relationship between HIV-1 and HCV shedding is intriguing and suggests a unique local interaction between these 2 viruses in the genital tract.”

Maternal-Child and Adolescent Center for Infectious Diseases and Virology, University of Southern California, Los Angeles; Mayo Clinic, Scottsdale, and St. Joseph's Hospital and Medical Center, Phoenix, Arizona; Medical Academy, Warsaw, Poland.

10/07/05

Source

M J Nowicki and others. Presence of Hepatitis C Virus (HCV) RNA in the Genital Tracts of HCV/HIV-1Coinfected Women. The Journal of Infectious Diseases 192(9): 1557-1565. November 1, 2005.

References

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14.    M J Nowicki and others. Presence of Hepatitis C Virus (HCV) RNA in the Genital Tracts of HCV/HIV-1Coinfected Women. The Journal of Infectious Diseases 192(9): 1557-1565. November 1, 2005.