title: Evaluation of the Antibody in Lymphocyte Supernatant Assay to Detect Active Tuberculosis.
abstract: BACKGROUND
  We aimed to evaluate the antibody in lymphocyte supernatant (ALS) assay as a biomarker to diagnose tuberculosis among adults from Tanzania with and without HIV.
  
  
  METHODS
  Adults admitted with suspicion for tuberculosis had sputa obtained for GeneXpert MTB/RIF, acid-fast bacilli smear and mycobacterial culture; blood was obtained prior to treatment initiation and after 4 weeks. Adults hospitalized with non-infectious conditions served as controls. Peripheral blood mononuclear cells were cultured unstimulated for 72 hours. Anti-mycobacterial antibodies were measured from culture supernatants by ELISA, using BCG vaccine as the coating antigen. Median ALS responses were compared between cases and controls at baseline and between cases over time.
  
  
  RESULTS
  Of 97 TB cases, 85 were microbiologically confirmed and 12 were clinically diagnosed. Median ALS responses from TB cases (0.366 OD from confirmed cases and 0.285 from clinical cases) were higher compared to controls (0.085, p<0.001). ALS responses did not differ based on HIV status, CD4 count or sputum smear status. Over time, the median ALS values declined significantly (0.357 at baseline; 0.198 after 4-weeks, p<0.001).
  
  
  CONCLUSIONS
  Robust ALS responses were mounted by patients with TB regardless of HIV status, CD4 count, or low sputum bacillary burden, potentially conferring a unique niche for this immunologic biomarker for TB.
authors.affiliation: Kilimanjaro Clinical Research Institute, Moshi, Tanzania.|Kilimanjaro Christian Medical University College, Moshi Tanzania.|Kilimanjaro Christian Medical Centre, Moshi, Tanzania.
authors.forename: Margaretha
authors.initials: M
authors.lastname: Sariko
authors.affiliation: University of Washington, Seattle, United States of America.
authors.forename: Caitlin
authors.initials: C
authors.lastname: Anderson
authors.affiliation: Kilimanjaro Clinical Research Institute, Moshi, Tanzania.
authors.forename: Buliga S
authors.initials: BS
authors.lastname: Mujaga
authors.affiliation: Kilimanjaro Clinical Research Institute, Moshi, Tanzania.|University of Virginia, Charlottesville, United States of America.
authors.forename: Jean
authors.initials: J
authors.lastname: Gratz
authors.affiliation: Kilimanjaro Clinical Research Institute, Moshi, Tanzania.|Kibong'oto Infectious Diseases Hospital, Kilimanjaro, Tanzania.
authors.forename: Stellah G
authors.initials: SG
authors.lastname: Mpagama
authors.affiliation: University of Virginia, Charlottesville, United States of America.
authors.forename: Scott
authors.initials: S
authors.lastname: Heysell
authors.affiliation: Kilimanjaro Clinical Research Institute, Moshi, Tanzania.|Kilimanjaro Christian Medical University College, Moshi Tanzania.|Kilimanjaro Christian Medical Centre, Moshi, Tanzania.
authors.forename: Gibson
authors.initials: G
authors.lastname: Kibiki
authors.affiliation: Kilimanjaro Clinical Research Institute, Moshi, Tanzania.|Kilimanjaro Christian Medical University College, Moshi Tanzania.|Kilimanjaro Christian Medical Centre, Moshi, Tanzania.
authors.forename: Blandina
authors.initials: B
authors.lastname: Mmbaga
authors.affiliation: University of Virginia, Charlottesville, United States of America.
authors.forename: Eric
authors.initials: E
authors.lastname: Houpt
authors.affiliation: University of Virginia, Charlottesville, United States of America.
authors.forename: Tania
authors.identifier: http://orcid.org/0000-0002-3929-6369
authors.initials: T
authors.lastname: Thomas
mesh_terms: D000328:Adult; D000907:Antibodies, Bacterial / Q000032:analysis*; D001681:Biological Assay / Q000379:methods*; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D015658:HIV Infections / Q000209:etiology* / Q000473:pathology; D006679:HIV Seropositivity / Q000150:complications*; D015497:HIV-1 / Q000502:physiology; D006801:Humans; D008214:Lymphocytes / Q000276:immunology*; D008297:Male; D009169:Mycobacterium tuberculosis / Q000472:pathogenicity*; D013183:Sputum / Q000382:microbiology; D013636:Tanzania; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000276:immunology / Q000382:microbiology
chemical_list: D000907:Antibodies, Bacterial