Consistency ofMycobacterium tuberculosis-Specific Interferon-Gamma Responses in HIV-1-Infected Women during Pregnancy and Postpartum

Sasi R Jonnalagadda,Elizabeth Brown,Grace C John-Stewart,Barbara Lohman-Payne,Lisa M Cranmer,Kenneth Tapia,Carey Farquhar,Dalton Wamalwa

doi:10.1155/2012/950650

Abstract

Background. We determined the consistency of positive interferon-gamma (IFN-γ) release assays (IGRAs) to detect latent TB infection (LTBI) over one-year postpartum in HIV-1-infected women. Methods. Women with positive IGRAs during pregnancy had four 3-monthly postpartum IGRAs. Postpartum change in magnitude of IFN-γ response was determined using linear mixed models. Results. Among 18 women with positive pregnancy IGRA, 15 (83%) had a subsequent positive IGRA; 9 (50%) were always positive, 3 (17%) were always negative, and 6 (33%) fluctuated between positive and negative IGRAs. Women with pregnancy IGRA IFN-γ>8 spot forming cells (SFCs)/well were more likely to have consistent postpartum IGRA response (odds ratio: 10.0; 95% confidence interval (CI): 0.9–117.0). Change in IFN-γ response over postpartum was 10.2 SFCs/well (95% CI: −1.5–21.8 SFCs/well). Conclusion. Pregnancy positive IGRAs were often maintained postpartum with increased consistency in women with higher baseline responses. There were modest increases in magnitude of IGRA responses postpartum.

Highlights

We determined the consistency of positive interferon-gamma (IFN-γ) release assays (IGRAs) to detect latent TB infection (LTBI) over one-year postpartum in human immunodeficiency virus type 1 (HIV-1)-infected women
We observed that HIV-1-infected women with latent TB infection (LTBI) as detected by a positive interferon-gamma (IFN-γ) release assay (IGRA) during pregnancy are at increased risk of active TB during the postpartum period [2]
Baseline characteristics of the 18 HIV-1-infected IGRA positive women selected for serial assessment were comparable to IGRA positive women (n = 117) from the cohort who were not included in this serial assessment study

Summary

Introduction

We determined the consistency of positive interferon-gamma (IFN-γ) release assays (IGRAs) to detect latent TB infection (LTBI) over one-year postpartum in HIV-1-infected women. Women with positive IGRAs during pregnancy had four 3-monthly postpartum IGRAs. Postpartum change in magnitude of IFN-γ response was determined using linear mixed models. Pregnancy positive IGRAs were often maintained postpartum with increased consistency in women with higher baseline responses. We observed that HIV-1-infected women with latent TB infection (LTBI) as detected by a positive interferon-gamma (IFN-γ) release assay (IGRA) during pregnancy are at increased risk of active TB during the postpartum period [2]. IGRAs during or after pregnancy may be useful in identifying women at increased risk for future active TB who in turn may expose their infants. IGRAs measure immune responses to MTB antigens: early secretory antigenic target 6-kD protein (ESAT-6) and culture filtrate protein 10 (CFP-10)

Objectives

Methods

Results

Conclusion