@article{101512,
  keywords = {Mycobacterium leprae, Diagnosis, lateral flow, Leprosy, IgM, Quantitative UCP-based rapid test, target product profile, Upconverting reporter particle},
  author = {Pierneef L and van Hooij A and de Jong D and Wassenaar G and Verhard E and Tjon Kon Fat E and Engel N and Khatun M and Soren S and Chowdhury AS and van Hees C and Corstjens P and Geluk A},
  title = {Rapid test for Mycobacterium leprae infection: a practical tool for leprosy},
  abstract = {<p><strong>Background:</strong> Detection of infection with Mycobacterium leprae allows timely prophylactic treatment, thereby reducing transmission as well as&nbsp;the risk of permanent, leprosy-associated nerve damage. However, since there is no worldwide-implemented standard test for M. leprae infection, detection of infection in asymptomatic individuals remains a major challenge for control programs in endemic areas. In previous studies, we developed and field-tested a lateral flow assay (LFA) quantitatively detecting human IgM against M. leprae-specific phenolic glycolipid I (anti-PGL-I), a marker for both active and past infection. This rapid test utilizes luminescent, background-free, up-converting reporter particles (UCP) and immunochromatography (i.e. the UCP-LF test platform) for accurate quantitation of anti-PGL-I IgM without operator bias. The aim of this study was to evaluate the final version of this quantitative UCP-based rapid test (i.e. PGL-I QURapid), using serum and fingerstick blood (FSB).</p>

<p><strong>Methods:</strong> The test comprises a lateral flow strip, in a standard plastic or biodegradable cassette. It can be provided with a humanized, recombinant control to monitor test performance and calculate accurate anti-PGL-I IgM levels. The performance of this QUR-test was assessed using serum and FSB from patients with leprosy (n = 214), tuberculosis (n = 20), buruli ulcer (n = 19), leishmaniasis (n = 14), non-tuberculous mycobacterial (n = 35) infections, as well as healthy Dutch individuals (n = 710) and humanized, recombinant anti-PGL-I IgM antibodies. Plot receiver operating characteristic curves were created and sensitivity (Sn), specificity (Sp) and the area under the curve were calculated to evaluate test performance.</p>

<p><strong>Results:</strong> Test results classified multibacillary leprosy patients with 95.0% Sn and 100% Sp using serum and 91.5% Sn and 99.8% Sp using FSB. Qualitative test results could be read after 2&nbsp;min flow time, with accurate quantitation from 10&nbsp;min onwards. The new anti-PGL-I IgM control supports production of batches with predetermined seropositivity thresholds and monitoring of the PGL-I&nbsp;QUR-test in various settings.</p>

<p><strong>Conclusion: </strong>The operational version of the PGL-I QURapid with point-of-care applicability, meets the WHO target product profile criteria. Thus, this QUR-test is ready for public health implementations. Graphical Abstract</p>
},
  year = {2024},
  journal = {Infectious Diseases of Poverty},
  volume = {13},
  pages = {1-12},
  publisher = {Springer Science and Business Media LLC},
  issn = {2049-9957},
  url = {https://idpjournal.biomedcentral.com/counter/pdf/10.1186/s40249-024-01262-9.pdf},
  doi = {10.1186/s40249-024-01262-9},
  language = {ENG},
}