Low Immune Activation in Women Starting ART During Pregnancy Increases Preterm Delivery Risk

Preterm delivery was found to be associated with low immune activation among women who began antiretroviral therapy (ART) for HIV infection during pregnancy, according to the findings of a prospective cohort study published in Clinical Infectious Diseases.

Women (N=90) with HIV who were at less than 24 weeks’ gestation were recruited at a public hospital in Cape Town, South Africa. The study participants were assessed for blood chemistry at 3 visits and for pregnancy outcomes based on when they began ART. Preterm birth was defined as delivery before 37 weeks’ gestation.

The median age of participants was 32 years (interquartile range [IQR], 26-36), 10% had a previous preterm delivery, 35% finished high school, and 36% were employed. The study participants were evenly split across the lowest (31%), medium (33%), and highest (29%) socioeconomic status groups.

Study participants began treatment with ART prior to pregnancy (n=47) or during antenatal care (n=43). Most women (88%) were given tenofovir disoproxil fumarate with lamivudine and efavirenz.

A decrease in CD8+ T-cell activation was seen in patients initiating ART, and activation levels were lowest for patients experiencing preterm delivery compared with all other groups.

Preterm birth was found to be decreased among women who commenced ART during antenatal care and who had CD8⁺ T-cell activation (adjusted odds ratio [aOR], 0.87; 95% CI, 0.76-1.00; P =.045), bulk CD14⁺ monocyte activation (aOR, 0.89; 95% CI, 0.82-0.97; P =.006), and mDC activation (aOR, 0.93; 95% CI, 0.87-0.99; P =.028). Risk of preterm delivery was associated with classical and intermediate monocytes (aOR, 1.20; 95% CI, 1.02-1.42; P =.031).

This study may have been limited by not stratifying the patients according to their ART treatment regimen. In addition, it remains unclear whether specific ART regimens contributed to the rate of preterm delivery. However, the study findings suggested that the immune system may be involved with preterm deliveries among women with HIV who start ART during early pregnancy. Additional studies are needed to identify biomarkers for preterm delivery and potential interventions.

Reference

Mdletshe N, Thobakgale C, Malaba TR, et al. Low immune activation in early pregnancy is associated with preterm but not small-for-gestational age delivery in HIV infected women initiating antiretroviral therapy in pregnancy: a PIMS case-control study in Cape Town, South Africa. Clin Infect Dis. Published online February 19, 2021. doi:10.1093/cid/ciab151