title: Comparing interferon-gamma release assays to tuberculin skin test in Thai children with tuberculosis exposure.
abstract: BACKGROUND
  Data on the performance of interferon-gamma release assays (IGRAs), QuantiFERON TB Gold In-tube (QFNGIT) and T-Spot.TB, in diagnosing tuberculosis (TB) are limited in Southeast Asia. This study aims to compare the performances of the two IGRAs and TST in Thai children with recent TB exposure.
  
  
  METHODS
  This multicenter, prospective study enrolled children with recent exposure to active TB adults. Children were investigated for active TB. TST was performed and blood collected for T-Spot.TB and QFNGIT.
  
  
  RESULTS
  158 children were enrolled (87% TB-exposed and 13% active TB, mean age 7.2 years). Only 3 children had HIV infection. 66.7% had TST≥10 mm, while 38.6% had TST≥15 mm. 32.5% had positive QFNGIT; 29.9% had positive T-Spot.TB. QFNGIT and T-Spot.TB positivity was higher among children with active TB compared with TB-exposed children. No indeterminate IGRA results were detected. No statistically significant differences between the performances of the IGRAs and TST at the two cut-offs with increasing TB exposure were detected. Concordance for positive IGRAs and TST ranged from 42-46% for TST≥10 mm and 62-67% for TST≥15 mm. On multivariable analyses, exposure to household primary/secondary caregiver with TB was associated with positive QFNGIT. Higher TB contact score and active TB were associated with positive T-Spot.TB.
  
  
  CONCLUSIONS
  Both QFNGIT and T-Spot.TB performed well in our Thai pediatric study population. No differences in the performances between tests with increasing TB exposure were found. Due to accessibility and low cost, using TST may more ideal than IGRAs in diagnosing latent and active TB in healthy children in Thailand and other similar settings.
authors.affiliation: Laboratory of Infectious Disease Prevention, Lindsley F. Kimball Research Institute, New York Blood Center, New York, New York, United States of America; Division of Infectious Diseases, Department of Medicine, Columbia University Medical Center, New York, New York, United States of America.
authors.forename: Hong-Van
authors.initials: HV
authors.lastname: Tieu
authors.affiliation: Queen Sirikit National Institute of Child Health, Bangkok, Thailand.
authors.forename: Piyarat
authors.initials: P
authors.lastname: Suntarattiwong
authors.affiliation: Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; HIV Netherlands Australia Thailand Research Collaboration (HIV-NAT), The Thai Red Cross AIDS Research Center, Bangkok, Thailand.
authors.forename: Thanyawee
authors.initials: T
authors.lastname: Puthanakit
authors.affiliation: Queen Sirikit National Institute of Child Health, Bangkok, Thailand.
authors.forename: Tawee
authors.initials: T
authors.lastname: Chotpitayasunondh
authors.affiliation: Department of Pediatrics, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Kulkanya
authors.initials: K
authors.lastname: Chokephaibulkit
authors.affiliation: Department of Medicine, Faculty of Medicine, Chulalonglongkorn University, Bangkok, Thailand.
authors.forename: Sunee
authors.initials: S
authors.lastname: Sirivichayakul
authors.affiliation: Department of Medicine, Faculty of Medicine, Chulalonglongkorn University, Bangkok, Thailand.
authors.forename: Supranee
authors.initials: S
authors.lastname: Buranapraditkun
authors.affiliation: SEARCH, The Thai Red Cross AIDS Research Center, Bangkok, Thailand.
authors.forename: Patcharawee
authors.initials: P
authors.lastname: Rungrojrat
authors.affiliation: SEARCH, The Thai Red Cross AIDS Research Center, Bangkok, Thailand.
authors.forename: Nitiya
authors.initials: N
authors.lastname: Chomchey
authors.affiliation: Division of Infectious Diseases, Department of Medicine, Columbia University Medical Center, New York, New York, United States of America.
authors.forename: Simon
authors.initials: S
authors.lastname: Tsiouris
authors.affiliation: Division of Infectious Diseases, Department of Medicine, Columbia University Medical Center, New York, New York, United States of America.
authors.forename: Scott
authors.initials: S
authors.lastname: Hammer
authors.affiliation: Laboratory of Infectious Disease Prevention, Lindsley F. Kimball Research Institute, New York Blood Center, New York, New York, United States of America.
authors.forename: Vijay
authors.initials: V
authors.lastname: Nandi
authors.affiliation: HIV Netherlands Australia Thailand Research Collaboration (HIV-NAT), The Thai Red Cross AIDS Research Center, Bangkok, Thailand; Department of Medicine, Faculty of Medicine, Chulalonglongkorn University, Bangkok, Thailand; SEARCH, The Thai Red Cross AIDS Research Center, Bangkok, Thailand; U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America.
authors.forename: Jintanat
authors.initials: J
authors.lastname: Ananworanich
mesh_terms: D000995:Antitubercular Agents / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D016358:Contact Tracing; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism*; D007538:Isoniazid / Q000627:therapeutic use; D008297:Male; D011446:Prospective Studies; D013785:Thailand; D014374:Tuberculin Test; D014376:Tuberculosis / Q000188:drug therapy / Q000635:transmission*
chemical_list: D000995:Antitubercular Agents; D007371:Interferon-gamma; D007538:Isoniazid