Nanoparticle capture of urinary lipoarabinomannan for diagnosing childhood tuberculosis
In brief
Nanoparticles raised digital urine TB test sensitivity to 64% in children
In a case-control study of 32 children, concentrating urine with nanoparticles raised the test's sensitivity from 0% to 63.9% with digital reading, while specificity was 90%. The small study suggests urine processing could help detect childhood TB without adding many false positives, but larger studies are needed to confirm performance.
- Journal
- Journal of clinical microbiology (Q1)
- Published
- 12 October 2026
- Study design
- Case-control study
- Evidence level
- Level 3, Low (CEBM 3b)
- Authors
- Kumail Ahmed, Brendan T Mullen, Najeeha T Iqbal, Tania A Thomas
- PMID
- 42861958
- DOI
- 10.1128/jcm.01559-25
Why clinicians should know about it
- Picked for Microbiology (medical) (paper of the day, 13 October 2026): Nanoparticle capture of urinary LAM improves TB diagnosis in children
Abstract
Urinary assays detecting lipoarabinomannan (LAM) as a diagnostic test for tuberculosis (TB) have limited sensitivity in pediatric populations. We aimed to evaluate the Ceres TB-Nanotrap to concentrate LAM and augment detection in urine using the Alere lateral flow assay (LF-LAM). This case-control study recruited 32 children with and without TB aged 1-18 years in Karachi, Pakistan, with banked urine specimens. TB case participants were classified as confirmed or unconfirmed TB using modified National Institutes of Health (NIH) consensus criteria. The LF-LAM test was performed before and after concentrating 5 mL of urine with TB-Nanotrap particles. Band intensity was measured via visual grading and digital quantification. Urine LAM sensitivity by visual grading was 4.5% (95% confidence interval [CI] 0.3-18.5) pre-concentration and 50.0% (95% CI 30.0-70.0) post-concentration. Sensitivity by digital quantification was 0.0% (95% CI 0.0-15.4) pre-concentration and 63.9% (95% CI 42.8-81.4) post-concentration. Specificity was high with both methods (visual grading: 90.0% [95% CI 62.8-99.4] pre-concentration and 90.0% [95% CI 62.8-99.4] post-concentration; digital analysis: 80.0% [95% CI 44.4-97.5] and 90.0% [95% CI 62.8-99.4], respectively). For cases, digital analysis showed an increase in median LF-LAM band intensity from 0.0 arbitrary units (AU) (interquartile range [IQR] 0.00-32.5) in unconcentrated samples to 98.4 AU (IQR 34.9-212.2) in concentrated samples. Concentration with TB-Nanotrap greatly increased sensitivity of urine LAM detection without a change in specificity. Use of TB-Nanotrap and digital quantitative analysis of urine LAM improved the diagnostic accuracy of the LF-LAM assay in this pediatric population and should be validated in larger studies.IMPORTANCEDiagnosing TB in children is challenging due to a lack of accurate and accessible diagnostic tests. In this study, we evaluated two methods of improving detection of TB in children using a commercially available urine test. First, we processed the urine to concentrate any available TB antigens. Second, we included a digital reader to interpret the test results. We found that concentrating urine and using a digital reader led to an increase in TB detection among children who had been diagnosed with TB, while minimizing false-positive results among children who did not have TB.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.