The Kidneys and Hepatitis C in Women

Historically, most studies in HIV research and treatment have been done using male volunteers. As a result, the precise impact of HIV and many HIV medicines on the health of HIV positive women may not be clear or may take a long time to uncover. In an attempt to begin to resolve this situation, researchers in the U.S. established the Women's Interagency HIV Study (WIHS). This study enrolled HIV positive women as well as women at high risk for this infection. Researchers noted the effects of HIV infection and, later, anti-HIV drugs on the women over a period of years. Health-related information collected on the women was entered into the WIHS database.

Recently, researchers completed an analysis of the impact of HCV co-infection on the kidney health of women in WIHS. Their findings suggest that in some HIV positive women, HCV co-infection increased the risk of kidney damage.

Study Details

Researchers analysed information on 2,684 HIV positive women, 945 (35%) of whom were co-infected with HCV. On average, the HCV co-infected women were described in this way by the research team:

"They were more likely to be older, African American, poor and drug users" at the time they entered the WIHS.

Results

At the start of the study, about 8% of the co-infected women had an eGFR of about 60, suggesting that they had chronic kidney disease (CKD).Moreover, co-infected women were twice as likely to have CKD as women who had HIV only.

Women who entered the study with CKD (an eGFR of less than 60) continued to have detectable kidney damage over the next five years. What's more, with each passing year their eGFR continued to fall, suggesting that CKD grew worse. On average, eGFRs fell by 5% each year among these women.

Even when researchers took into account many factors, they still found that having HCV coinfection was statistically a more powerful predictor of declining kidney health over time than any of the following factors:

• illicit substance use
• diabetes
• high blood pressure
• CD4+ counts
• HAART use
• HIV viral load

The findings from this study should not be entirely surprising -- larger studies of HCV positive people who don't have HIV have found similar results.

HCV infection might play a role in declining kidney health through the following ways:

• HCV could damage the membrane used in the filtering units of the kidney.
• HCV could accelerate kidney injury caused by HIV, diabetes or hypertension, which are likely pre-existing conditions in some people with HCV.

The findings from the WIHS study need to be confirmed and extended in other co-infected women.

Reference

1. Tsui J, Vittinghoff E, Anastos K, et al. Hepatitis C seropositivity and kidney function decline among women with HIV: data from the Women's Interagency HIV Study. American Journal of Kidney Diseases. 2009 Jul;54(1):43-50.

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