Loop-Mediated Isothermal Amplification (LAMP) Assay for Rapid and Accurate Confirmatory Diagnosis of HTLV-1/2 Infection
Yago Gomes,
Adele Caterino-de-Araujo,
Karoline Campos,
Maria Gisele Gonçalves,
Ana Claudia Leite,
Marco Antonio Lima,
Abelardo Araújo,
Marcus Tulius Silva,
Otávio Espíndola
Affiliations
Yago Gomes
Laboratory for Clinical Research in Neuroinfections, Evandro Chagas National Institute of Infectious Diseases (INI), Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro 21040-900, Brazil
Adele Caterino-de-Araujo
Laboratory of HTLV Research, Immunology Center, Adolfo Lutz Institute, São Paulo 01246-000, Brazil
Karoline Campos
Laboratory of HTLV Research, Immunology Center, Adolfo Lutz Institute, São Paulo 01246-000, Brazil
Maria Gisele Gonçalves
Laboratory of HTLV Research, Immunology Center, Adolfo Lutz Institute, São Paulo 01246-000, Brazil
Ana Claudia Leite
Laboratory for Clinical Research in Neuroinfections, Evandro Chagas National Institute of Infectious Diseases (INI), Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro 21040-900, Brazil
Marco Antonio Lima
Laboratory for Clinical Research in Neuroinfections, Evandro Chagas National Institute of Infectious Diseases (INI), Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro 21040-900, Brazil
Abelardo Araújo
Laboratory for Clinical Research in Neuroinfections, Evandro Chagas National Institute of Infectious Diseases (INI), Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro 21040-900, Brazil
Marcus Tulius Silva
Laboratory for Clinical Research in Neuroinfections, Evandro Chagas National Institute of Infectious Diseases (INI), Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro 21040-900, Brazil
Otávio Espíndola
Laboratory for Clinical Research in Neuroinfections, Evandro Chagas National Institute of Infectious Diseases (INI), Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro 21040-900, Brazil
Laboratory diagnosis of human T-lymphotropic viruses (HTLV) 1 and 2 infection is performed by serological screening and further confirmation with serological or molecular assays. Thus, we developed a loop-mediated isothermal nucleic acid amplification (LAMP) assay for the detection of HTLV-1/2 in blood samples. The sensitivity and accuracy of HTLV-1/2 LAMP were defined with DNA samples from individuals infected with HTLV-1 (n = 125), HTLV-2 (n = 19), and coinfected with HIV (n = 82), and compared with real-time polymerase chain reaction (qPCR) and PCR-restriction fragment length polymorphism (RFLP). The overall accuracy of HTLV-1/2 LAMP (95% CI 74.8–85.5%) was slightly superior to qPCR (95% CI 69.5–81.1%) and similar to PCR-RFLP (95% CI 79.5–89.3%). The sensitivity of LAMP was greater for HTLV-1 (95% CI 83.2–93.4%) than for HTLV-2 (95% CI 43.2–70.8%). This was also observed in qPCR and PCR-RFLP, which was associated with the commonly lower HTLV-2 proviral load. All molecular assays tested showed better results with samples from HTLV-1/2 mono-infected individuals compared with HIV-coinfected patients, who present lower CD4 T-cell counts. In conclusion, HTLV-1/2 LAMP had similar to superior performance than PCR-based assays, and therefore may represent an attractive alternative for HTLV-1/2 diagnosis due to reduced working time and costs, and the simple infrastructure needed.
