- Category: HIV/HCV Coinfection
- Published on Friday, 30 March 2012 00:00
- Written by Liz Highleyman
Effective antiretroviral therapy (ART) for HIV and maintaining a high CD4 T-cell count may decrease the risk of hepatitis C virus (HCV) transmission from HIV/HCV coinfected mothers to their babies, according to study findings presented at the 19th Conference on Retroviruses and Opportunistic Infections (CROI 2012) this month in Seattle.
Most studies of mother-to-child HCV transmission among HIV negative women have found rates below 5%. Considerably higher rates -- up to 19% -- have been seen among HIV/HCV coinfected mothers, but some of these studies looked at women with uncontrolled HIV disease and advanced immune deficiency before effective combination ART was widely available.
Claudia Checa Cabot from Hospital General de Agudos Jose Maria Ramos Mejia in Buenos Aires and colleagues evaluated rates of vertical HCV transmission among HIV positive women in 2 prospective observational cohort studies -- NISDI Perinatal (2002-2008) and LILAC (2008-present) -- in Argentina, the Bahamas, Brazil, Jamaica, Mexico, and Peru. Participants had available HCV test results and returned for a 6-month postnatal visit by December 31, 2008.
A total of 739 women and their singleton infants met the inclusion criteria; 669 had HIV alone and 70 were HIV/HCV coinfected. Women who tested positive for HCV antibodies were also tested for HCV RNA viral load, as were those with CD4 counts below 200 cells/mm3 as their immune systems were potentially too impaired to produce sufficient antibodies.
Infants with detectable HCV RNA were considered to be infected; those with early HCV RNA positive samples followed by HCV RNA negative results at 6 months were classified as having transient HCV infection.
- 67 women (9%) tested positive for HCV antibodies, 44 of the 67 (66%) were also HCV RNA positive, and 3 women with low CD4 counts were HCV RNA positive but not antibody positive.
- Among the 70 women with detectable HCV RNA, 29 (62%) had genotype 1, 9 (19%) had genotype 3, and 9 (19%) were undetermined.
- All HIV/HCV coinfected women took antiretroviral drugs during pregnancy, with 80% receiving combination therapy for at least 28 days.
- A majority (74%) of the women with detectable HCV RNA had HIV viral load < 1000 copies/mL at the time of delivery.
- Women with HIV viral load > 10,000 copies/mL or HIV clinical disease stage C at enrollment were about twice as likely to be coinfected with HCV (odds ratio 2.27 and 2.12, respectively).
- Coinfected women had significantly lower mean CD4 cell and platelet counts, and higher HIV viral load on average at enrollment.
- 4 of the 47 infants born to women with detectable HCV RNA, or 8.5%, were found to be HCV infected, including 1 with transient infection; none were HIV infected.
- 2 HCV-infected infants were born via vaginal delivery and 2 via scheduled Cesarean section.
- All mothers of infants testing positive for HCV RNA had HCV viral loads greater than 3,500,000 copies/mL during pregnancy; however, as a group, mothers of HCV-infected infants did not have significantly higher average HCV RNA than mothers of uninfected babies (6.78 vs 6.46 log, respectively).
- All mothers of HCV-infected infants had HIV viral load < 1000 copies/mL and CD4 counts > 350 cells/mm3 at delivery (range 357 to 700 cells/mm3).
Based on these findings, the researchers concluded, "The HCV mother-to-child transmission rate among HIV/HCV coinfected women with access to highly active ART and well-controlled HIV infection may be lower than the transmission rates that were previously reported in other HIV/HCV coinfected populations, although our sample size and duration of study follow-up are limitations."
However, having a low HIV viral load and higher CD4 count at the time of delivery did not fully protect against HCV transmission.
"When contrasted with the 9% overall [HCV antibody] prevalence in the general study population, the relatively high prevalence of HCV infection in [HCV antibody] negative, severely immunocompromised women may advocate for HCV RNA testing of this population," they suggested.
C Checa Cabot, S Stoszek, J Quarleri, et al.MTCT of HCV among HIV/HCV-co-Infected Women. 19th Conference on Retroviruses and Opportunistic Infections (CROI 2012). Seattle, WA. March 5-8, 2012. Abstract 742.