Overview

The WHO End TB Strategy calls for the early diagnosis of TB and universal drug susceptibility testing (DST), highlighting the critical role of laboratories for rapidly and accurately detecting TB and drug resistance. Molecular assays based on nucleic acid amplification techniques such as polymerase chain reaction (PCR) have been developed for rapid TB diagnosis and are being implemented in developing countries. A commercial molecular assay Loopamp MTBC Detection Kit based on loop-mediated isothermal amplification was developed by Eiken Chemical Company Ltd (Tokyo, Japan) for the detection of Mycobacterium tuberculosis complex (TB-LAMP).

TB-LAMP is a manual assay that requires less than one hour to perform and can be read with the naked eye under ultra violet light. Following review of the latest evidence, WHO recommends that TB-LAMP can be used as a replacement for microscopy for the diagnosis of pulmonary TB in adults with signs and symptoms of TB. It can also be considered as a follow-on test to microscopy in adults with signs and symptoms of pulmonary TB, especially when further testing of sputum smear-negative specimens is necessary.

Contents

• Acknowledgements
• Abbreviations
• Declarations and management of conflicts of interests
• Executive summary
• 1. Background
  • Index test
• 2. Methods
  • 2.1. Evidence synthesis
  • 2.2. Criteria for considering studies for this review
  • 2.3. Data collection and analysis
  • 2.4. Guideline Development Group meeting
  • 2.5. External Review Group
• 3. Scope
  • 3.1. Target audience
• 4. Evidence base for policy formulation
  • 4.1. Assessment of methodological quality
• 5. Systematic review results
  • 5.1. Accuracy of TB-LAMP as a replacement test for smear microscopy
  • 5.2. Accuracy of TB-LAMP as a replacement test for smear microscopy in persons living with HIV
  • 5.3. Accuracy of TB-LAMP as an add-on test following smear microscopy for smear-negative adults
  • 5.4. Accuracy of TB-LAMP compared with Xpert MTB/RIF for detection of a pulmonary TB
  • 5.5. Evaluation of the proportion of indeterminate/invalid results when TB-LAMP is used to detect pulmonary TB among all adults and among HIV-infected adults?
• 6. Cost-effectiveness analysis
• 7. Summary of evidence to recommendations
  • 7.1. TB-LAMP for the detection of pulmonary TB in all adults
  • 7.2. TB-LAMP for the detection of pulmonary TB in adults with HIV
  • 7.3. TB-LAMP as an add-on test following a negative smear microscopy for the detection of pulmonary TB in adults
  • 7.4. TB-LAMP as a replacement test for Xpert MTB/RIF for the detection of pulmonary TB in adults
• 8. WHO Policy recommendations
  • Remarks
• 9. Implementation considerations
• 10. Plans for disseminating the WHO policy guidance on TB-LAMP
• 11. Research needs
• Annex 1. References to studies for the review of the diagnostic accuracy of TB-LAMP
• Annex 2. GRADE Evidence Profiles
• Annex 3. Abstracts for unpublished studies
• Annex 4. Evidence to recommendations tables

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