title: Evaluation of antigen-specific immunoglobulin g responses in pulmonary tuberculosis patients and contacts.
abstract: This study aimed to evaluate the serodiagnostic potential of immunoglobulin G (IgG) responses to Mycobacterium tuberculosis antigens in pulmonary tuberculosis (TB) patients, recent TB contacts with latent TB infection (LTBI), and healthy subjects. Infections were assessed using tuberculin skin tests, QuantiFERON-TB Gold In-Tube tests, drug susceptibility testing, and molecular genotyping of clinical isolates. Serum IgG responses to selective M. tuberculosis antigens, including the 38-kDa and 16-kDa antigens, lipoarabinomannan (LAM), and recombinant early secreted antigen target 6 kDa (ESAT-6) and culture filtrate protein 10 kDa (CFP-10), were determined. We found that the serum IgG responses to all antigens might differentiate between active TB and LTBI, with LAM having the highest diagnostic value (area under the curve [AUC] of 0.7756, P < 0.001). Recurrent TB cases showed significantly higher IgG responses to 38 kDa, CFP-10 (P < 0.01), and LAM (P < 0.05) than new cases, and male patients had higher levels of antigen-specific IgG than females (P < 0.05). Conversely, drug resistance and patient body mass index did not affect IgG responses (P > 0.05). LAM-specific IgG responses differentiated between acid-fast bacillus (AFB) smear-positive and -negative patients (P < 0.01), whereas antigen-specific IgG responses did not vary with the M. tuberculosis genotype (P > 0.05). Significantly higher IgG responses to 38 kDa and 16 kDa were observed in AFB smear-negative patients than in controls. These results suggest that assessment of serum IgG responses to selective purified M. tuberculosis antigens may help improve the diagnosis of active TB, particularly for sputum smear-negative patients or recurrent cases, and these may also help to differentiate between active TB and LTBI.
authors.affiliation: Department of Microbiology and Institute of Immunology and Immunological Diseases, Brain Korea 21 Plus Project for the Medical Sciences, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Yun-Gyoung
authors.initials: YG
authors.lastname: Hur
authors.affiliation: Department of Microbiology and Institute of Immunology and Immunological Diseases, Brain Korea 21 Plus Project for the Medical Sciences, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Ahreum
authors.initials: A
authors.lastname: Kim
authors.affiliation: Division of Pulmonology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Young Ae
authors.initials: YA
authors.lastname: Kang
authors.affiliation: National Mokpo Hospital, Mokpo, Jeonnam, Republic of Korea.
authors.forename: An Sik
authors.initials: AS
authors.lastname: Kim
authors.affiliation: National Mokpo Hospital, Mokpo, Jeonnam, Republic of Korea.
authors.forename: Dae Yeon
authors.initials: DY
authors.lastname: Kim
authors.affiliation: Department of Biomedical Laboratory Science, College of Health Sciences, Yonsei University, Wonju, Gangwon, Republic of Korea.
authors.forename: Yeun
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Department of Microbiology and Institute of Immunology and Immunological Diseases, Brain Korea 21 Plus Project for the Medical Sciences, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Youngmi
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Department of Biomedical Laboratory Science, College of Health Sciences, Yonsei University, Wonju, Gangwon, Republic of Korea.
authors.forename: Hyeyoung
authors.initials: H
authors.lastname: Lee
authors.affiliation: Department of Microbiology and Institute of Immunology and Immunological Diseases, Brain Korea 21 Plus Project for the Medical Sciences, Yonsei University College of Medicine, Seoul, Republic of Korea raycho@yuhs.ac.
authors.forename: Sang-Nae
authors.initials: SN
authors.lastname: Cho
mesh_terms: D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial / Q000276:immunology*; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D008297:Male; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D012698:Serologic Tests / Q000379:methods; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D007074:Immunoglobulin G