Rapid urinary lipoarabinomannan test with laboratory-level sensitivity for tuberculosis detection: a performance...

Area of Science:

• Tuberculosis diagnostics
• Rapid diagnostic tests
• Urinary biomarkers

Background:

• Developing rapid, non-sputum-based tuberculosis (TB) tests is crucial for global health.
• Current diagnostic methods have limitations in speed and accessibility.
• Lipoarabinomannan (LAM) is a key biomarker for TB detection.

Purpose of the Study:

• To evaluate the analytical and diagnostic performance of a novel rapid diagnostic test (RDT), the plasmonic fluor (PF)-enhanced urinary lipoarabinomannan lateral flow assay (PF-LAM).
• To compare PF-LAM with existing non-sputum TB tests, including Alere Determine TB LAM Ag (AlereLAM) and electrochemiluminescence LAM assay (EclLAM).

Main Methods:

• Analytical performance of PF-LAM was assessed for detection limit, precision, stability, and lot-to-lot variation.
• Two sub-studies used banked urine samples: a preclinical study (399 samples) and a diagnostic accuracy study (77 samples).
• Performance was compared against the microbiology reference standard (MRS), including Xpert MTB/RIF and culture.

Main Results:

• In the preclinical study, PF-LAM sensitivity was 33.8% versus 5.5% for AlereLAM, with both showing 98.5% specificity.
• In the diagnostic accuracy study, PF-LAM achieved 58% sensitivity and 98% specificity, outperforming EclLAM (42% sensitivity, 95% specificity).
• PF-LAM demonstrated high precision and minimal lot-to-lot variability.

Conclusions:

• PF-LAM exhibits superior analytical and diagnostic sensitivity compared to both AlereLAM and EclLAM.
• The test shows high precision and minimal lot-to-lot variability, making it a reliable tool.
• PF-LAM represents a significant advancement in non-sputum-based rapid diagnostics for tuberculosis.