3 research outputs found
Fingerstick test quantifying humoral and cellular biomarkers indicative for M-leprae infection
Objectives: 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.
Methods: 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.
Results: Correlations between serum and FSB from the same individuals for αPGL-I, CRP and IP-10 were highly
significant (p < .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.
Conclusions: 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
Longitudinal Immune Responses and Gene Expression Profiles in Type 1 Leprosy Reactions
Immunogenetics and cellular immunology of bacterial infectious disease