title: Active tuberculosis patients have high levels of IgA anti-alpha-crystallin and isocitrate lyase proteins.
abstract: Mexico City, Mexico.
  
  
  
  To identify proteins synthetised by Mycobacterium tuberculosis in hypoxic culture, which resemble more closely a granuloma environment than aerobic culture, and to determine if they are recognised by antibodies from patients with active pulmonary tuberculosis (PTB).
  
  
  
  Soluble extracts from M. tuberculosis H37Rv cultured under aerobic or hypoxic conditions were analysed using two-dimensional polyacrylamide gel electrophoresis, and proteins over-expressed under hypoxia were identified by mass spectrometry. The presence of immunoglobulin (Ig) G, IgA and IgM antibodies against these proteins was determined in the serum of 42 patients with active PTB and 42 healthy controls.
  
  
  
  We selected three M. tuberculosis H37Rv proteins (alpha-crystallin protein [Acr, Rv2031c], universal stress protein Rv2623 and isocitrate lyase [ICL, RV0467]) that were over-expressed under hypoxia. Titres of anti-Acr and anti-ICL IgA antibodies were higher in patients than in healthy controls, with an area under the receiver operating characteristic curve of 0.71 for anti-ICL IgA antibodies.
  
  
  
  ICL could be used in combination with other M. tuberculosis antigens to improve the sensitivity and specificity of current serological TB diagnostic methods.
authors.affiliation: Departamento de Inmunología, Programa de Posgrado en Inmunología.
authors.forename: M
authors.initials: M
authors.lastname: Talavera-Paulín
authors.affiliation: Departamento de Microbiología, Programa de Posgrado en Biomedicina y Biotecnología Molecular, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional (IPN), Mexico City.
authors.forename: L
authors.initials: L
authors.lastname: García-Morales
authors.affiliation: Departamento de Inmunología, Programa de Posgrado en Inmunología.
authors.forename: B P
authors.initials: BP
authors.lastname: Ruíz-Sánchez
authors.affiliation: Centro de Investigaciones Regionales 'Dr Hideyo Noguchi', Universidad Autónoma de Yucatán, Yucatán.
authors.forename: Á D
authors.initials: ÁD
authors.lastname: Caamal-Ley
authors.affiliation: Servicio de Neumología, Hospital General de México 'Dr Eduardo Liceaga', Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Secretaría de Salud, Mexico City.
authors.forename: A
authors.initials: A
authors.lastname: Hernández-Solis
authors.affiliation: Servicio de Neumología, Hospital General de México 'Dr Eduardo Liceaga', Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Secretaría de Salud, Mexico City.
authors.forename: E
authors.initials: E
authors.lastname: Ramírez-Casanova
authors.affiliation: Servicio de Neumología, Hospital General de México 'Dr Eduardo Liceaga', Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Secretaría de Salud, Mexico City.
authors.forename: R
authors.initials: R
authors.lastname: Cicero-Sabido
authors.affiliation: Departamento de Inmunología, Instituto de Investigaciones Biomédicas, UNAM, Mexico City.
authors.forename: C
authors.initials: C
authors.lastname: Espitia
authors.affiliation: Isidro Espinosa de los Reyes Instituto Nacional de Perinatología, Mexico City.
authors.forename: C
authors.initials: C
authors.lastname: Helguera-Repetto
authors.affiliation: Departamento de Microbiología.
authors.forename: J A
authors.initials: JA
authors.lastname: González-Y-Merchand
authors.affiliation: Departamento de Inmunología, Escuela Superior de Medicina, IPN, Mexico City, Mexico.
authors.forename: R
authors.initials: R
authors.lastname: Flores-Mejía
authors.affiliation: Departamento de Inmunología.
authors.forename: S
authors.initials: S
authors.lastname: Estrada-Parra
authors.affiliation: Departamento de Inmunología.
authors.forename: I
authors.initials: I
authors.lastname: Estrada-García
authors.affiliation: Departamento de Inmunología.
authors.forename: R
authors.initials: R
authors.lastname: Chacón-Salinas
authors.affiliation: Departamento de Inmunología.
authors.forename: I
authors.initials: I
authors.lastname: Wong-Baeza
authors.affiliation: Departamento de Inmunología.
authors.forename: J
authors.initials: J
authors.lastname: Serafín-López
mesh_terms: D000328:Adult; D000368:Aged; D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial / Q000097:blood; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood*; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D007522:Isocitrate Lyase / Q000276:immunology*; D008297:Male; D008800:Mexico; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification; D012680:Sensitivity and Specificity; D014397:Tuberculosis, Pulmonary / Q000097:blood / Q000175:diagnosis*; D055815:Young Adult; D038201:alpha-Crystallins / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D038201:alpha-Crystallins; C072681:Mycobacterium tuberculosis antigens; D007522:Isocitrate Lyase