In the JournalsPerspective

ART does not affect vaginal microbiome, study suggests

Neither ART nor immune reconstitution affect the vaginal microbiome of HIV-infected women, according to the results of an observational study published in Open Forum Infectious Diseases.

“To our knowledge, this is the first study that examines the vaginal microbiome during ART initiation,” Cindy M. Liu, MD, PhD, MPH, associate professor of environmental and occupational health at the George Washington University Milken Institute School of Public Health, and colleagues wrote. “In this study, ART initiation and subsequent immune reconstitution did not appear to modify the vaginal microbiome. There was no significant change in the overall vaginal microbiome composition following ART initiation, regardless of CD4 T cell reconstitution.”

According to Reynolds and colleagues, few studies have characterized the vaginal microbiome of women with HIV living in sub-Saharan Africa, an area with high HIV prevalence and transmission. They noted that previous research has shown that Lactobacillus deficiency and an abundance of anaerobes within the vagina are associated with negative gynecologic and obstetric outcomes, including acquisition of STIs such as HIV, and that bacterial vaginosis (BV)-associated anaerobes are common in the vaginal microbiomes of African and African American women compared with women from other ethnic and racial backgrounds.

Reynolds and colleagues evaluated the vaginal microbiomes of 92 women in Uganda coinfected with HIV-1 and HSV-2, using self-collected vaginal swabs at 1 month before ART initiation and at 4 and 6 months after initiation. They used 16S ribosomal RNA gene-based sequencing and quantitative PCR to characterize the vaginal microbiome, and assessed vaginal community state types (CSTs) using proportional abundance data. They used permutational analyses of variance to measure changes in microbiome composition.

The researchers identified five vaginal CSTs that varied significantly by bacterial load (P < .01). One was characterized by Lactobacillus iners, one by Gardnerella, one by Gardnerella and Prevotella, one by Lactobacillus crispatus and one that was highly diverse, they reported.

Immune reconstitution following ART initiation did not impact vaginal microbiome CST assignment (P = .722) or individual-level changes in bacterial load (P = .40), they wrote. The vaginal microbiome exhibited no significant changes in composition following ART initiation (P = .985).

Liu and colleagues concluded that further research is needed to determine the long-term impact of ART on the vaginal microbiome. – by Joe Gramigna

Disclosures: The authors report no relevant financial disclosures.

Neither ART nor immune reconstitution affect the vaginal microbiome of HIV-infected women, according to the results of an observational study published in Open Forum Infectious Diseases.

“To our knowledge, this is the first study that examines the vaginal microbiome during ART initiation,” Cindy M. Liu, MD, PhD, MPH, associate professor of environmental and occupational health at the George Washington University Milken Institute School of Public Health, and colleagues wrote. “In this study, ART initiation and subsequent immune reconstitution did not appear to modify the vaginal microbiome. There was no significant change in the overall vaginal microbiome composition following ART initiation, regardless of CD4 T cell reconstitution.”

According to Reynolds and colleagues, few studies have characterized the vaginal microbiome of women with HIV living in sub-Saharan Africa, an area with high HIV prevalence and transmission. They noted that previous research has shown that Lactobacillus deficiency and an abundance of anaerobes within the vagina are associated with negative gynecologic and obstetric outcomes, including acquisition of STIs such as HIV, and that bacterial vaginosis (BV)-associated anaerobes are common in the vaginal microbiomes of African and African American women compared with women from other ethnic and racial backgrounds.

Reynolds and colleagues evaluated the vaginal microbiomes of 92 women in Uganda coinfected with HIV-1 and HSV-2, using self-collected vaginal swabs at 1 month before ART initiation and at 4 and 6 months after initiation. They used 16S ribosomal RNA gene-based sequencing and quantitative PCR to characterize the vaginal microbiome, and assessed vaginal community state types (CSTs) using proportional abundance data. They used permutational analyses of variance to measure changes in microbiome composition.

The researchers identified five vaginal CSTs that varied significantly by bacterial load (P < .01). One was characterized by Lactobacillus iners, one by Gardnerella, one by Gardnerella and Prevotella, one by Lactobacillus crispatus and one that was highly diverse, they reported.

Immune reconstitution following ART initiation did not impact vaginal microbiome CST assignment (P = .722) or individual-level changes in bacterial load (P = .40), they wrote. The vaginal microbiome exhibited no significant changes in composition following ART initiation (P = .985).

Liu and colleagues concluded that further research is needed to determine the long-term impact of ART on the vaginal microbiome. – by Joe Gramigna

Disclosures: The authors report no relevant financial disclosures.

    Perspective
    Jeanne M. Marrazzo

    Jeanne M. Marrazzo

    The vaginal bacterial microbial community has long been known to play a key role in mediating healthy reproductive tract outcomes, notably in the risks for adverse pregnancy outcomes (preterm birth, low birth weight, chorioamnionitis) and of acquisition of STIs, including HIV. A vaginal microbiome dominated by L. crispatus or Lactobacillus jensenii offers the best protection against these adverse events. With an increasing shift to anaerobic diversity (and ultimately BV), the environment experiences a decline of protective immunity as defined by both soluble mediators and cell-associated mechanisms. Thus, exogenous products, such as oral or vaginal antimicrobials, should ideally not perturb an optimal environment, and in a perfect world, promote one.

    Based on their spectrum of activity, antiretroviral (ARV) medications should theoretically not present a problem in this regard; however, confirming this is important, because BV independently increases a woman’s risk for transmitting HIV to her male sexual partner, even when controlling for genital HIV viral load. The study by Liu and colleagues is reassuring, if not definitive. In a relatively small number of women coinfected with HSV-2 in Uganda, these investigators found no difference in the abundance of various community members in the vaginal microbiome after the initiation of ARVs; of note, the total abundance of Gardnerella vaginalis declined after ARV initiation in a subset of women. These data suggest that we need not caution women initiating ARVs to anticipate that their vaginal environment will be modified or that ARVs will interfere with normal dynamics of the vaginal microbiome.

    • Jeanne M. Marrazzo, MD, MPH
    • Infectious Disease News Editorial Board member
      Director, division of infectious diseases
      C. Glenn Cobbs, MD, Endowed Professor in Infectious Diseases
      University of Alabama at Birmingham School of Medicine

    Disclosures: Marrazzo reports no relevant financial disclosures.