title: Short Communication: Failures in Detecting HTLV-1 and HTLV-2 in Patients Infected with HIV-1.
abstract: Changes in retrovirus acquisition/transmission behaviors have been reported in Brazil, with a concerning increase in HIV-1-infected individuals aged 15-39 years. In São Paulo, HIV-1/HTLV-1 and HIV-1/HTLV-2 coinfections have been associated with intravenous drug use and failure to detect HTLV-1/2 (human T cell lymphotropic virus types 1 and 2) with immunosuppression and the use of highly active antiretroviral therapy (HAART). Negative results for HTLV serologic [western blotting (WB)] and molecular [real-time PCR pol (qPCR)] confirmatory assays have been reported, whereas the best sensitivity has been found for INNO-LIA (LIA). In this study, we expand our previous data by analyzing a group of young patients (n = 1,383; median age 35.6 years) who recently acquired HIV by sexual contact, the majority of whom were HAART naïve, and comparing the performances of four HTLV confirmatory assays: LIA, WB, qPCR, and PCR-RFLP (tax). We confirmed HTLV infection in 58 (4.2%) blood samples: 29 HTLV-1, 24 HTLV-2, 1 HTLV-1+HTLV-2, and 4 HTLV. LIA, WB, qPCR, and PCR-RFLP sensitivities were 94.8%, 82.8%, 79.2%, and 74.5%, respectively. Associations of HTLV infection with female gender (OR = 2.28, 1.31-4.00) and age >40 years (p < .0001) were detected. The results confirm the low sensitivities of molecular assays and the best performance of LIA in detecting HTLV-1/2 in such patients. We hypothesize that the negative PCR results are due to the presence of defective provirus and/or low proviral load circulating in such patients, with inconclusive WB coinciding with the seroconversion period. Corroborating the associations obtained, repeated exposure is required for HTLV sexual transmission/acquisition, which is more efficient from male to female.
authors.affiliation: Centro de Imunologia, Instituto Adolfo Lutz , Secretaria de Estado da Saúde de São Paulo, São Paulo, Brazil .
authors.forename: Karoline Rodrigues
authors.initials: KR
authors.lastname: Campos
authors.affiliation: Centro de Imunologia, Instituto Adolfo Lutz , Secretaria de Estado da Saúde de São Paulo, São Paulo, Brazil .
authors.forename: Maria Gisele
authors.initials: MG
authors.lastname: Gonçalves
authors.affiliation: Centro de Imunologia, Instituto Adolfo Lutz , Secretaria de Estado da Saúde de São Paulo, São Paulo, Brazil .
authors.forename: Adele
authors.initials: A
authors.lastname: Caterino-de-Araujo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001938:Brazil; D002648:Child; D002675:Child, Preschool; D003955:Diagnostic Tests, Routine / Q000379:methods*; D005260:Female; D015658:HIV Infections / Q000150:complications*; D015490:HTLV-I Infections / Q000175:diagnosis*; D015491:HTLV-II Infections / Q000175:diagnosis*; D015368:Human T-lymphotropic virus 1 / Q000302:isolation & purification*; D015367:Human T-lymphotropic virus 2 / Q000302:isolation & purification*; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D055815:Young Adult
keywords: HIV-1; HTLV-1; HTLV-2; coinfection; diagnosis; risk factors