02818nas a2200241   4500000000100000008004100001100001600042700001200058700001500070700001100085700001500096700001400111700001300125700001500138700001500153700001700168700001100185700001200196245010100208856008300309520217000392022001402562       2019                            d1 aCorstjens P1 aHooij A1 aKon Fat ET1 aAlam K1 aVrolijk LB1 aDlamini S1 aSilva MB1 aSpencer JS1 aSalgado CG1 aRichardus JH1 aHees C1 aGeluk A00aFingerstick test quantifying humoral and cellular biomarkers indicative for M. leprae infection.  uhttps://www.sciencedirect.com/science/article/pii/S0009912018307604?via%3Dihub3 a<p><strong>OBJECTIVES: </strong>New user-friendly diagnostic tests for detection of individuals infected by Mycobacterium leprae (M. leprae), the causative pathogen of leprosy, can help guide therapeutic and prophylactic treatment, thus positively contributing to clinical outcome and reduction of transmission. To facilitate point-of-care testing without the presence of phlebotomists, the use of fingerstick blood (FSB) rather than whole blood-derived serum is preferred. This study is a first proof-of-principle validating that previously described rapid serum tests detecting antibodies and cytokines can also be used with FSB.</p>

<p><strong>METHODS: </strong>Quantitative detection of previously identified biomarkers for leprosy and M. leprae infection, anti-M. leprae PGL-I IgM antibodies (αPGL-I), IP-10 and CRP, was performed with lateral flow (LF) strips utilizing luminescent up-converting reporter particles (UCP) and a portable reader generating unbiased read-outs. Precise amounts of FSB samples were collected using disposable heparinized capillaries. Biomarker levels in paired FSB and serum samples were determined using UCP-LF test strips for leprosy patients and controls in Bangladesh, Brazil, South-Africa and the Netherlands.</p>

<p><strong>RESULTS: </strong>Correlations between serum and FSB from the same individuals for αPGL-I, CRP and IP-10 were highly significant (p &lt; .0001) even after FSB samples had been frozen. The αPGL-I FSB test was able to correctly identify all multibacillary leprosy patients presenting a good quantitative correlation with the bacterial index.</p>

<p><strong>CONCLUSIONS: </strong>Reader-assisted, quantitative UCP-LF tests for the detection of humoral and cellular biomarkers for M. leprae infection, are compatible with FSB. This allows near-patient testing for M. leprae infection and immunomonitoring of treatment without highly trained staff. On site availability of test-result concedes immediate initiation of appropriate counselling and treatment. Alternatively, the UCP-LF format allows frozen storage of FSB samples compatible with deferred testing in central laboratories.</p>
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