title: IgG, IgM and IgA antibodies against the novel polyprotein in active tuberculosis.
abstract: BACKGROUND
  The present study was aimed to evaluate whether IgG, IgM and IgA antibodies levels detected against a novel Mycobacterium tuberculosis polyprotein 38 F-64 F (with 38 F being the abbreviation for 38kD-ESAT6-CFP10 and 64 F for Mtb8.4-MPT64-TB16.3-Mtb8) are suitable for diagnosing active tuberculosis, and for monitoring the efficacy of chemotherapy on TB patients.
  
  
  METHODS
  In this study, a total of 371 active TB patients without treatment were selected and categorized into S+/C+group (n=143), S-/C+group (n=106) or S-/C- group (n=122). A series of serum samples were collected from 82 active TB patients who had undergone anti-TB chemotherapy for 0-6 months at one month interval. Humoral responses (IgG, IgM and IgA) were determined for the novel Mycobacterium tuberculosis polyprotein using indirect ELISA methods in all of serum samples.
  
  
  RESULTS
  For S+/C+, S-/C+and S-/C- active tuberculosis patients before anti-TB chemotherapy, the sensitivities of tests based on IgG were 65.7%, 46.2% and 52.5% respectively; the sensitivities based on IgM were 21.7%, 24.5% and 18.9%; and the sensitivities based on IgA were 25.2%, 17.9% and 23.8%. By combination of three isotypes, for all active tuberculosis patients, the test sensitivity increased to 70.4% with the specificity being 91.5%. After anti-TB chemotherapy, there were no significant differences between groups with different courses of anti-TB chemotherapy.
  
  
  CONCLUSIONS
  The novel Mycobacterium tuberculosis polyprotein 38 F-64 F represents potential antigen suitable for measuring IgG, IgM and IgA antibodies. However, the serodiagnostic test based on the 38 F-64 F polyprotein appears unsuitable for monitoring the efficacy of chemotherapy.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Feng
authors.forename: Xiqin
authors.initials: X
authors.lastname: Yang
authors.forename: Bingshui
authors.initials: B
authors.lastname: Xiu
authors.forename: Shuang
authors.initials: S
authors.lastname: Qie
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Dai
authors.forename: Kun
authors.initials: K
authors.lastname: Chen
authors.forename: Ping
authors.initials: P
authors.lastname: Zhao
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.forename: Russell A
authors.initials: RA
authors.lastname: Nicholson
authors.forename: Guohua
authors.initials: G
authors.lastname: Wang
authors.forename: Xiaoguo
authors.initials: X
authors.lastname: Song
authors.affiliation: Department of Bio-diagnosis, Beijing Institute of Basic Medical Sciences, Beijing 100850, China. zhangheqiu2004@126.com.
authors.forename: Heqiu
authors.initials: H
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000368:Aged; D000907:Antibodies, Bacterial / Q000097:blood* / Q000276:immunology; D000995:Antitubercular Agents / Q000627:therapeutic use; D001426:Bacterial Proteins / Q000276:immunology*; D016903:Drug Monitoring; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood* / Q000276:immunology; D007074:Immunoglobulin G / Q000097:blood* / Q000276:immunology; D007075:Immunoglobulin M / Q000097:blood* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000276:immunology* / Q000302:isolation & purification; D020815:Polyproteins / Q000276:immunology*; D014376:Tuberculosis / Q000097:blood* / Q000175:diagnosis / Q000188:drug therapy / Q000276:immunology / Q000382:microbiology; D055815:Young Adult
chemical_list: D000907:Antibodies, Bacterial; D000995:Antitubercular Agents; D001426:Bacterial Proteins; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D020815:Polyproteins