title: Pregnancy differentially impacts performance of latent tuberculosis diagnostics in a high-burden setting.
abstract: BACKGROUND
  Targeted screening for latent TB infection (LTBI) in vulnerable populations is a recommended TB control strategy. Pregnant women are at high risk for developing TB and likely to access healthcare, making pregnancy an important screening opportunity in developing countries. The sensitivity of the widely-used tuberculin skin test (TST), however, may be reduced during pregnancy.
  
  
  METHODS
  We performed a cross-sectional study comparing the TST with the QuantiFERON Gold In-tube (QGIT) in 401 HIV-negative women presenting antepartum (n = 154), at delivery (n = 148), or postpartum (n = 99) to a government hospital in Pune, India. A subset of 60 women enrolled during pregnancy was followed longitudinally and received both tests at all three stages of pregnancy.
  
  
  RESULTS
  The QGIT returned significantly more positive results than the TST. Of the 401 women in the cross-sectional study, 150 (37%) had a positive QGIT, compared to 59 (14%) for the TST (p<0.005). Forty-nine (12%) did not have their TST read. Of 356 who had both results available, 46 (13%) were concordant positive, 91 (25%) were discordant (12 (3%) TST+/QGIT-; 79 (22%) TST-/QGIT+), and 206 (57%) concordant negative. Comparison by stage of pregnancy revealed that QGIT percent positivity remained stable between antepartum and delivery, unlike TST results (QGIT 31-32% vs TST 11-17%). Median IFN-γ concentration was lower at delivery than in antepartum or postpartum (1.66 vs 2.65 vs 8.99 IU/mL, p = 0.001). During postpartum, both tests had significantly increased positives (QGIT 31% vs 32% vs 52%, p = 0.01; TST 17% vs 11% vs 25%, p<0.005). The same trends were observed in the longitudinal subset.
  
  
  CONCLUSIONS
  Timing and choice of LTBI test during pregnancy impact results. QGIT was more stable and more closely approximated the LTBI prevalence in India. But pregnancy stage clearly affects both tests, raising important questions about how the complex immune changes brought on by pregnancy may impact LTBI screening.
authors.affiliation: Division of Infectious Diseases, Weill Cornell Medical College, New York, New York, United States of America.
authors.forename: Jyoti S
authors.initials: JS
authors.lastname: Mathad
authors.affiliation: Department of Obstetrics and Gynaecology, Byramjee Jeejeebhoy Government Medical College- Sassoon General Hospital, Pune, Maharashtra, India.
authors.forename: Ramesh
authors.initials: R
authors.lastname: Bhosale
authors.affiliation: Byramjee Jeejeebhoy Government Medical College- Johns Hopkins Clinical Trials Unit, Pune, Maharashtra, India.
authors.forename: Vikrant
authors.initials: V
authors.lastname: Sangar
authors.affiliation: Byramjee Jeejeebhoy Government Medical College- Johns Hopkins Clinical Trials Unit, Pune, Maharashtra, India; Division of Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Vidya
authors.initials: V
authors.lastname: Mave
authors.affiliation: Byramjee Jeejeebhoy Government Medical College- Johns Hopkins Clinical Trials Unit, Pune, Maharashtra, India; Division of Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Nikhil
authors.initials: N
authors.lastname: Gupte
authors.affiliation: Byramjee Jeejeebhoy Government Medical College- Johns Hopkins Clinical Trials Unit, Pune, Maharashtra, India.
authors.forename: Savita
authors.initials: S
authors.lastname: Kanade
authors.affiliation: Byramjee Jeejeebhoy Government Medical College- Johns Hopkins Clinical Trials Unit, Pune, Maharashtra, India.
authors.forename: Ashwini
authors.initials: A
authors.lastname: Nangude
authors.affiliation: Byramjee Jeejeebhoy Government Medical College- Johns Hopkins Clinical Trials Unit, Pune, Maharashtra, India.
authors.forename: Kavita
authors.initials: K
authors.lastname: Chopade
authors.affiliation: Byramjee Jeejeebhoy Government Medical College- Johns Hopkins Clinical Trials Unit, Pune, Maharashtra, India.
authors.forename: Nishi
authors.initials: N
authors.lastname: Suryavanshi
authors.affiliation: Byramjee Jeejeebhoy Government Medical College- Johns Hopkins Clinical Trials Unit, Pune, Maharashtra, India.
authors.forename: Prasad
authors.initials: P
authors.lastname: Deshpande
authors.affiliation: Byramjee Jeejeebhoy Government Medical College- Johns Hopkins Clinical Trials Unit, Pune, Maharashtra, India.
authors.forename: Vandana
authors.initials: V
authors.lastname: Kulkarni
authors.affiliation: Division of Infectious Diseases, Weill Cornell Medical College, New York, New York, United States of America.
authors.forename: Marshall J
authors.initials: MJ
authors.lastname: Glesby
authors.affiliation: Division of Infectious Diseases, Weill Cornell Medical College, New York, New York, United States of America.
authors.forename: Daniel
authors.initials: D
authors.lastname: Fitzgerald
authors.affiliation: Department of Microbiology, Byramjee Jeejeebhoy Government Medical College- Sassoon General Hospital, Pune, Maharashtra, India.
authors.forename: Renu
authors.initials: R
authors.lastname: Bharadwaj
authors.affiliation: Department of Obstetrics and Gynaecology, Byramjee Jeejeebhoy Government Medical College- Sassoon General Hospital, Pune, Maharashtra, India.
authors.forename: Pradeep
authors.initials: P
authors.lastname: Sambarey
authors.affiliation: Byramjee Jeejeebhoy Government Medical College- Johns Hopkins Clinical Trials Unit, Pune, Maharashtra, India; Division of Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Amita
authors.initials: A
authors.lastname: Gupta
mesh_terms: D000293:Adolescent; D000328:Adult; D003430:Cross-Sectional Studies; D036861:Delivery, Obstetric; D003951:Diagnostic Errors; D005260:Female; D006801:Humans; D007194:India; D059425:Interferon-gamma Release Tests; D055985:Latent Tuberculosis / Q000175:diagnosis*; D008403:Mass Screening; D049590:Postpartum Period; D011247:Pregnancy / Q000276:immunology; D011251:Pregnancy Complications, Infectious / Q000175:diagnosis* / Q000276:immunology / Q000517:prevention & control; D011262:Pregnancy Trimester, Second; D011263:Pregnancy Trimester, Third; D014374:Tuberculin Test / Q000379:methods