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Bertão-Santos A, Dias LDS, Ribeiro-Alves M, Pinheiro RO, Moraes MO, Manta FSDN, Costa ADT. Validation of the performance of a point of care molecular test for leprosy: From a simplified DNA extraction protocol to a portable qPCR. PLoS Negl Trop Dis 2024; 18:e0012032. [PMID: 39374296 DOI: 10.1371/journal.pntd.0012032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 09/23/2024] [Indexed: 10/09/2024] Open
Abstract
The study aimed to optimize qPCR reactions using oligonucleotides from the first Brazilian molecular diagnostic kit for leprosy on a portable platform (Q3-Plus). In addition, we sought to develop a simplified protocol for DNA extraction that met point-of-care criteria. During optimization on the Q3-Plus, optical parameters, thresholds, and cutoffs for the 16S rRNA and RLEP targets of M. leprae were established using synthetic DNA, purified DNA from M. leprae, and pre-characterized clinical samples. For the simplified extraction protocol, different lysis solutions were evaluated using chaotropic agents, and purification was carried out by transferring the lysed material to FTA cards. The complete protocol (simplified extraction + qPCR on the portable platform) was then evaluated with pre-characterized clinical skin biopsy samples and compared with standard equipment (QuantStudio-5). LOD95% for the optimized reactions was 113.31 genome-equivalents/μL for 16S rRNA and 17.70 genome-equivalents/μL for RLEP. Among the lysis solutions, the best-performing was composed of urea (2 M), which provided good dissolution of the skin fragment and a lower Ct value, indicating higher concentrations of DNA. The complete technological solution showed a sensitivity of 52% in reactions. Our results highlight the need for additional optimization to deal with paucibacillary samples, but also demonstrate the feasibility of the portable platform for the qPCR detection of M. leprae DNA in low infrastructure settings.
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Affiliation(s)
- Amanda Bertão-Santos
- Laboratório de Ciências e Tecnologias Aplicadas à Saúde (LaCTAS), Instituto Carlos Chagas, Fundação Oswaldo Cruz (FIOCRUZ), Curitiba, Brazil
| | - Larisse da Silva Dias
- Laboratório de Hanseníase, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | - Marcelo Ribeiro-Alves
- Laboratório de Pesquisa Clínica em DST e AIDS, Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | - Roberta Olmo Pinheiro
- Laboratório de Hanseníase, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | - Milton Ozório Moraes
- Laboratório de Hanseníase, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | | | - Alexandre Dias Tavares Costa
- Laboratório de Ciências e Tecnologias Aplicadas à Saúde (LaCTAS), Instituto Carlos Chagas, Fundação Oswaldo Cruz (FIOCRUZ), Curitiba, Brazil
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Hasker E, Assoumani Y, Randrianantoandro A, Ramboarina S, Braet SM, Cauchoix B, Baco A, Mzembaba A, Salim Z, Amidy M, Grillone S, Attoumani N, Grillone SH, Ronse M, Peeters Grietens K, Rakoto-Andrianarivelo M, Harinjatovo H, Supply P, Snijders R, Hoof C, Tsoumanis A, Suffys P, Rasamoelina T, Corstjens P, Ortuno-Gutierrez N, Geluk A, Cambau E, de Jong BC. Post-exposure prophylaxis in leprosy (PEOPLE): a cluster randomised trial. Lancet Glob Health 2024; 12:e1017-e1026. [PMID: 38762282 DOI: 10.1016/s2214-109x(24)00062-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 01/24/2024] [Accepted: 02/03/2024] [Indexed: 05/20/2024]
Abstract
BACKGROUND Post-exposure prophylaxis (PEP) using single-dose rifampicin reduces progression from infection with Mycobacterium leprae to leprosy disease. We compared effectiveness of different administration modalities, using a higher (20 mg/kg) dose of rifampicin-single double-dose rifampicin (SDDR)-PEP. METHODS We did a cluster randomised study in 16 villages in Madagascar and 48 villages in Comoros. Villages were randomly assigned to four study arms and inhabitants were screened once a year for leprosy, for 4 consecutive years. All permanent residents (no age restriction) were eligible to participate and all identified patients with leprosy were treated with multidrug therapy (SDDR-PEP was provided to asymptomatic contacts aged ≥2 years). Arm 1 was the comparator arm, in which no PEP was provided. In arm 2, SDDR-PEP was provided to household contacts of patients with leprosy, whereas arm 3 extended SDDR-PEP to anyone living within 100 m. In arm 4, SDDR-PEP was offered to household contacts and to anyone living within 100 m and testing positive to anti-phenolic glycolipid-I. The main outcome was the incidence rate ratio (IRR) of leprosy between the comparator arm and each of the intervention arms. We also assessed the individual protective effect of SDDR-PEP and explored spatial associations. This trial is registered with ClinicalTrials.gov, NCT03662022, and is completed. FINDINGS Between Jan 11, 2019, and Jan 16, 2023, we enrolled 109 436 individuals, of whom 95 762 had evaluable follow-up data. Our primary analysis showed a non-significant reduction in leprosy incidence in arm 2 (IRR 0·95), arm 3 (IRR 0·80), and arm 4 (IRR 0·58). After controlling for baseline prevalence, the reduction in arm 3 became stronger and significant (IRR 0·56, p=0·0030). At an individual level SDDR-PEP was also protective with an IRR of 0·55 (p=0·0050). Risk of leprosy was two to four times higher for those living within 75 m of an index patient at baseline. INTERPRETATION SDDR-PEP appears to protect against leprosy but less than anticipated. Strong spatial associations were observed within 75 m of index patients. Targeted door-to-door screening around index patients complemented by a blanket SDDR-PEP approach will probably have a substantial effect on transmission. FUNDING European and Developing Countries Clinical Trials Partnership. TRANSLATION For the French translation of the abstract see Supplementary Materials section.
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Affiliation(s)
- Epco Hasker
- Institute of Tropical Medicine, Antwerp, Belgium.
| | | | | | | | | | | | - Abdallah Baco
- National Tuberculosis and Leprosy Control Program, Moroni, Comoros
| | | | - Zahara Salim
- National Tuberculosis and Leprosy Control Program, Moroni, Comoros
| | - Mohammed Amidy
- National Tuberculosis and Leprosy Control Program, Moroni, Comoros
| | - Saverio Grillone
- National Tuberculosis and Leprosy Control Program, Moroni, Comoros
| | - Nissad Attoumani
- National Tuberculosis and Leprosy Control Program, Moroni, Comoros
| | | | - Maya Ronse
- Institute of Tropical Medicine, Antwerp, Belgium
| | | | | | | | - Philip Supply
- University Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019-UMR 9017, Center for Infection and Immunity of Lille, Lille, France
| | | | | | | | - Philip Suffys
- Oswaldo Cruz Institute, Fiocruz, Laboratory of Molecular Biology Applied to Mycobacteria, Rio de Janeiro, Brazil
| | | | | | | | | | - Emmanuelle Cambau
- Inserm, IAME, Université Paris Cité, UMR 1137, Paris, France; AP-HP, Hôpital Bichat, Service de Mycobacteriologie Specialisee et de Reference, Paris, France
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Lopes-Luz L, Saavedra DP, Fogaça MBT, Bührer-Sékula S, Stefani MMDA. Challenges and advances in serological and molecular tests to aid leprosy diagnosis. Exp Biol Med (Maywood) 2023; 248:2083-2094. [PMID: 38059475 PMCID: PMC10800132 DOI: 10.1177/15353702231209422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/08/2023] Open
Abstract
Leprosy is a neglected chronic infectious disease caused by obligate intracellular bacilli, Mycobacterium leprae and Mycobacterium lepromatosis. Despite multidrug therapy (MDT) success, leprosy accounts for more than 200,000 new cases yearly. Leprosy diagnosis remains based on the dermato-neurologic examination, but histopathology of skin biopsy and bacilloscopy of intradermal scraping are subsidiary diagnostic tests that require expertise and laboratory infrastructure. This minireview summarizes the state of the art of serologic tests to aid leprosy diagnosis, highlighting enzyme-linked immunosorbent assay (ELISA) and point-of-care tests (POCT) biotechnologies. Also, the impact of the postgenomic era on the description of new recombinantly expressed M. leprae-specific protein antigens, such as leprosy Infectious Disease Research Institute (IDRI) diagnostic (LID)-1 is summarized. Highly specific and sensitive molecular techniques to detect M. leprae DNA as the quantitative polymerase chain reaction (qPCR) and the loop-mediated isothermal amplification (LAMP) are briefly reviewed. Serology studies using phenolic glycolipid-I (PGL-I) semi-synthetic antigens, LID-1 fusion antigen, and the single fusion complex natural disaccharide-octyl (NDO)-LID show high sensitivity in multibacillary (MB) patients. However, serology is not applicable to paucibacillary patients, as they have weak humoral response and robust cell-mediated response, requiring tests for cellular biomarkers. Unlike ELISA-based tests, leprosy-specific POCT based on semi-synthetic PGL-I antigens and NDO-LID 1 antigen is easy to perform, cheaper, equipment-free, and can contribute to early diagnosis avoiding permanent incapacities and helping to interrupt M. leprae transmission. Besides its use to help diagnosis of household contacts or at-risk populations in endemic areas, potential applications of leprosy serology include monitoring MDT efficacy, identification of recent infection, especially in young children, as surrogate markers of disease progression to orient adult chemoprophylaxis and as a predictor of type 2 leprosy reactions. Advances in molecular biology techniques have reduced the complexity and execution time of qPCR confirming its utility to help diagnosis while leprosy-specific LAMP holds promise as an adjunct test to detect M. leprae DNA.
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Affiliation(s)
- Leonardo Lopes-Luz
- Laboratório de Desenvolvimento e Produção de Testes Rápidos, Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia 74605-050, Brasil
- Innovation Hub in Point of Care Technologies, UFG-Merck S/A. Alliance, Goiânia 74690-900, Brasil
| | - Djairo Pastor Saavedra
- Laboratório de Desenvolvimento e Produção de Testes Rápidos, Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia 74605-050, Brasil
- Innovation Hub in Point of Care Technologies, UFG-Merck S/A. Alliance, Goiânia 74690-900, Brasil
| | - Matheus Bernardes Torres Fogaça
- Laboratório de Desenvolvimento e Produção de Testes Rápidos, Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia 74605-050, Brasil
- Innovation Hub in Point of Care Technologies, UFG-Merck S/A. Alliance, Goiânia 74690-900, Brasil
| | - Samira Bührer-Sékula
- Laboratório de Desenvolvimento e Produção de Testes Rápidos, Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia 74605-050, Brasil
- Innovation Hub in Point of Care Technologies, UFG-Merck S/A. Alliance, Goiânia 74690-900, Brasil
| | - Mariane Martins de Araújo Stefani
- Laboratório de Desenvolvimento e Produção de Testes Rápidos, Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia 74605-050, Brasil
- Innovation Hub in Point of Care Technologies, UFG-Merck S/A. Alliance, Goiânia 74690-900, Brasil
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