TY - JOUR
T1 - Fingerstick test quantifying humoral and cellular biomarkers indicative for M. leprae infection
AU - Corstjens, Paul L.A.M.
AU - van Hooij, Anouk
AU - Tjon Kon Fat, Elisa M.
AU - Alam, Korshed
AU - Vrolijk, Loes B.
AU - Dlamini, Sipho
AU - da Silva, Moises Batista
AU - Spencer, John S.
AU - Salgado, Claudio G.
AU - Richardus, Jan Hendrik
AU - van Hees, Colette L.M.
AU - Geluk, Annemieke
N1 - Publisher Copyright:
© 2019 The Authors
PY - 2019/4
Y1 - 2019/4
N2 - 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.
AB - 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.
KW - CRP
KW - Diagnosis
KW - Fingerstick blood
KW - IP-10
KW - Leprosy
KW - PGL-I
KW - Rapid test
KW - UCP-LFA
KW - Upconverting nanoparticles
UR - http://www.scopus.com/inward/record.url?scp=85060512986&partnerID=8YFLogxK
U2 - 10.1016/j.clinbiochem.2019.01.007
DO - 10.1016/j.clinbiochem.2019.01.007
M3 - Article
C2 - 30695682
AN - SCOPUS:85060512986
SN - 0009-9120
VL - 66
SP - 76
EP - 82
JO - Clinical Biochemistry
JF - Clinical Biochemistry
ER -
