Association between plasma interferon-γ levels and preeclampsia in pregnant women screened for tuberculosis infection

Abstract

Objectives

Pregnancy can influence immune control of Mycobacterium tuberculosis infection (MtbI). We recently reported an association between MtbI and pregnancy complications, particularly severe preeclampsia, in a registry-based cohort of women originating in tuberculosis-endemic countries screened for MtbI in Swedish antenatal care, implying a potential role of MtbI for the development of preeclampsia. Here, we aimed to investigate the role of plasma interferon-γ secretion as a potential mediator of this interaction.

Methods

Plasma interferon-γ levels were compared with women with MtbI (defined as positive QuantiFERON results in the absence of tuberculosis) and MtbI-negative women regarding any diagnosis of preeclampsia and severe preeclampsia. Odds of preeclampsia and severe preeclampsia were compared with respect to MtbI status and interferon-γ levels >90th percentile in the study population (0.28 IU/mL).

Results

MtbI was detected in 700 of 3605 women (19.4%) and preeclampsia was diagnosed in 110 (3.1%), among whom 50 (1.4%) had severe preeclampsia. Women with MtbI had higher interferon-γ levels than MtbI-negative women (median 0.12 IU/mL, interquartile range [IQR], 0.06–0.26 IU/mL; vs. 0.07 IU/mL, IQR 0.04–0.12 IU/mL; p < 0.001). The prevalence of preeclampsia of any grade (13/159, 8.2%, odds ratio [OR], 2.79; 95% CI, 1.52–5.12; p < 0.001) and severe preeclampsia (10/159, 6.3%, OR, 5.46; 95% CI, 2.64–11.3; p < 0.0001) was higher in women with MtbI and interferon-γ levels >0.28 IU/mL, than in MtbI-negative women with interferon-γ levels <0.28 IU/mL. Neither women with MtbI with interferon-γ levels <0.28 IU/mL, nor MtbI-negative women with interferon-γ levels >0.28 IU/mL, had increased odds of preeclampsia or severe preeclampsia compared to MtbI-negative women with interferon-γ levels <0.28 IU/mL.

Discussion

These findings suggest that interferon-γ secretion could be involved as a mediator in the association between MtbI and development of preeclampsia.