Performance of QuantiFERON-TB Gold Plus for detection of latent tuberculosis infection in pregnant women living in a tuberculosis- and HIV-endemic setting

PLoS One. 2018 Apr 4;13(4):e0193589. doi: 10.1371/journal.pone.0193589. eCollection 2018.

Abstract

We evaluated the performance of QuantiFERON-TB Gold Plus (QFT-Plus), which includes two Mycobacterium tuberculosis antigen formulations (TB1 and TB2), for detection of latent tuberculosis infection during pregnancy. Eight-hundred-twenty-nine Ethiopian pregnant women (5.9% HIV-positive) were tested with QFT-Plus, with bacteriological sputum analysis performed for women with clinically suspected tuberculosis and HIV-positive women irrespective of clinical presentation. QFT-Plus read-out was categorized according to the conventional cut-off (0.35 IU/ml) for both antigen formulations. In addition, we analysed the distribution of QFT-Plus results within a borderline zone (0.20-0.70 IU/ml), and interferon-γ response in relation to HIV infection and gestational age. Two-hundred-seventy-seven women (33%) were QFT-Plus-positive (HIV-positive 16/49 [33%]; HIV-negative 261/780 [33%]). There was a strong agreement between the two antigen formulations (κ = 0.92), with discordant results in 29 cases (3.5%). Whereas discordant QFT-Plus results were rare in pregnancy, several results with both TB1 and TB2 within the borderline range were observed (11/49 [22%] vs. 43/780 [5.5%] in HIV-positive and HIV-negative women, respectively; p<0.0001). HIV-positive women had lower absolute interferon-γ levels (TB1: 0.47 vs. 2.16 IU/ml; p<0.001, TB2: 0.49 vs. 2.24 IU/ml, p<0.001, considering results ≥0.20 IU/ml) compared to HIV-negative women. QFT-Plus-positive women who submitted samples at later stages of pregnancy had lower mitogen- (p<0.001) but higher TB-antigen-specific (p = 0.031 for TB1, p = 0.061 for TB2) interferon-γ response. Considering their lower capacity to produce TB-specific interferon-γ, a lower cut-off level for defining QFT-Plus-positivity may be considered in HIV-positive pregnant women.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Ethiopia / epidemiology
  • Female
  • HIV / isolation & purification
  • HIV Infections / blood
  • HIV Infections / diagnosis*
  • HIV Infections / epidemiology
  • Humans
  • Interferon-gamma / blood
  • Interferon-gamma Release Tests / methods*
  • Latent Tuberculosis / blood
  • Latent Tuberculosis / diagnosis*
  • Latent Tuberculosis / epidemiology
  • Mycobacterium tuberculosis / isolation & purification
  • Pregnancy
  • Pregnancy Complications, Infectious / blood
  • Pregnancy Complications, Infectious / diagnosis*
  • Pregnancy Complications, Infectious / epidemiology
  • Tuberculin Test / methods*
  • Young Adult

Substances

  • Interferon-gamma

Grants and funding

Funding for the study was obtained through a private donation to Lund University. Qiagen (https://www.qiagen.com) provided the QuantiFERON-TB Gold Plus kits free of charge for the purpose of this study, but had no influence on the study design. Qiagen, represented by L. Masae Kawamura, M.D, was allowed to read and comment on the final editions of the manuscript but did not influence the presentation of results or their interpretation.