title: Evaluation of a simple loop-mediated isothermal amplification test kit for the diagnosis of tuberculosis.
abstract: OBJECTIVE
  A new loop-mediated isothermal amplification (LAMP) test kit, including a simple DNA extraction device for the detection of Mycobacterium tuberculosis complex, was developed for commercial use and evaluated for its usefulness in diagnosing tuberculosis (TB).
  
  
  METHODS
  The LAMP test was performed using untreated and N-acetyl-L-cysteine (NALC) NaOH-treated sputum specimen. The efficiency of the kit was compared with other conventional laboratory examinations, including other nucleic acid amplification (NAA) tests.
  
  
  RESULTS
  The sensitivity of LAMP  using raw sputum (direct LAMP) in smear- and culture-positive specimens was 98.2% (95%CI 94.9-99.4), while the sensitivity in smear-negative, culture-positive specimens was 55.6% (95%CI 43.4-68.0). The diagnostic sensitivity of direct LAMP for the diagnosis of individuals with  TB was 88.2% (95%CI 81.4-92.7). The sensitivity values of direct LAMP were slightly, but not statistically significantly lower than those of Cobas Amplicor MTB and TRC Rapid MTB, while the sensitivity of the LAMP test using NALC-NaOH treated sputum was significantly lower than other  NAA tests (P < 0.05) for smear-negative, culture-positive specimens. The new commercial version of the LAMP kit was easy to handle and yielded results within 1 h of receiving sputum specimens.
  
  
  CONCLUSIONS
  This test is considered a promising diagnostic tool for TB, even for peripheral  laboratories with limited equipment, such as those in developing countries.
authors.affiliation: Department of Mycobacterium Reference and Research, Bacteriology Division, Research Institute of Tuberculosis, Japan Anti-Tuberculosis Association, Tokyo, Japan. mitarai@jata.or.jp
authors.forename: S
authors.initials: S
authors.lastname: Mitarai
authors.forename: M
authors.initials: M
authors.lastname: Okumura
authors.forename: E
authors.initials: E
authors.lastname: Toyota
authors.forename: T
authors.initials: T
authors.lastname: Yoshiyama
authors.forename: A
authors.initials: A
authors.lastname: Aono
authors.forename: A
authors.initials: A
authors.lastname: Sejimo
authors.forename: Y
authors.initials: Y
authors.lastname: Azuma
authors.forename: K
authors.initials: K
authors.lastname: Sugahara
authors.forename: T
authors.initials: T
authors.lastname: Nagasawa
authors.forename: N
authors.initials: N
authors.lastname: Nagayama
authors.forename: A
authors.initials: A
authors.lastname: Yamane
authors.forename: R
authors.initials: R
authors.lastname: Yano
authors.forename: H
authors.initials: H
authors.lastname: Kokuto
authors.forename: K
authors.initials: K
authors.lastname: Morimoto
authors.forename: M
authors.initials: M
authors.lastname: Ueyama
authors.forename: M
authors.initials: M
authors.lastname: Kubota
authors.forename: R
authors.initials: R
authors.lastname: Yi
authors.forename: H
authors.initials: H
authors.lastname: Ogata
authors.forename: S
authors.initials: S
authors.lastname: Kudoh
authors.forename: T
authors.initials: T
authors.lastname: Mori
mesh_terms: D000111:Acetylcysteine / Q000737:chemistry; D004269:DNA, Bacterial / Q000032:analysis; D003906:Developing Countries; D006801:Humans; D009169:Mycobacterium tuberculosis / Q000235:genetics / Q000302:isolation & purification*; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D012680:Sensitivity and Specificity; D012972:Sodium Hydroxide / Q000737:chemistry; D013183:Sputum / Q000382:microbiology; D014376:Tuberculosis / Q000175:diagnosis* / Q000382:microbiology
chemical_list: D004269:DNA, Bacterial; D012972:Sodium Hydroxide; D000111:Acetylcysteine