title: The best algorithm to confirm the diagnosis of HTLV-1 and HTLV-2 in at-risk individuals from São Paulo, Brazil.
abstract: The ability to confirm the diagnosis of human T-lymphotropic virus types 1 and 2 (HTLV-1 and HTLV-2) in at-risk individuals in São Paulo, Brazil by Western blotting (WB), conventional polymerase chain reaction (tax and pol PCR) and real-time PCR (pol) is compared. Seventy-three blood samples that were reactive in HTLV-1/2 serological screening enzyme immunoassays (EIAs) were evaluated. HTLV-1/2 was confirmed in 53 blood samples: 48 were positive by WB, 41 were positive by PCR and 42 scored positive by real-time PCR assays (37 of 48 WB-positive samples plus five WB-indeterminate samples that were further confirmed by sequencing). Although WB was able to detect more cases of HTLV-1/2 infection, the real-time PCR assay was able to discriminate between these two viruses and confirm an individual HTLV-1/HTLV-2 diagnosis in two HTLV WB-untyped samples and five WB-indeterminate samples. Because of the large number of WB-indeterminate samples and the cost of the WB assay in Brazil, it is proposed an algorithm that employs two EIAs for screening and then real-time PCR to confirm the infection, followed by testing any PCR-negative samples with the WB assay. This strategy reduces costs and improves the accuracy of the diagnosis of HTLV-1/2.
authors.affiliation: Immunology Department, Instituto Adolfo Lutz, Coordenadoria de Controle de Doenças da Secretaria de Estado da Saúde de São Paulo, Av. Dr. Arnaldo, 355, 11° andar, 01246-902, São Paulo, SP, Brazil.
authors.forename: Emanuela A S
authors.initials: EA
authors.lastname: Costa
authors.forename: Mariana C
authors.initials: MC
authors.lastname: Magri
authors.forename: Adele
authors.initials: A
authors.lastname: Caterino-de-Araujo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001769:Blood / Q000821:virology; D015153:Blotting, Western / Q000379:methods; D001938:Brazil; D002648:Child; D002675:Child, Preschool; D019411:Clinical Laboratory Techniques / Q000379:methods*; D005260:Female; D015490:HTLV-I Infections / Q000175:diagnosis*; D015491:HTLV-II Infections / Q000175:diagnosis*; D015368:Human T-lymphotropic virus 1 / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D015367:Human T-lymphotropic virus 2 / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000379:methods; D014773:Virology / Q000379:methods*; D055815:Young Adult