title: Laboratory characterization of human T cell lymphotropic virus types 1 (HTLV-1) and 2 (HTLV-2) infections in blood donors from Sao Paulo, Brazil.
abstract: Serologic screening for human T cell lymphotropic virus types 1/2 (HTLV-1/2) infection in blood donors has been recently introduced in Brazil. Analysis of 351,639 blood donations in Sao Paulo from January 1992 to October 1993 identified 1,063 positive (0.30%) and 2,238 indeterminate (0.63%) samples based on serologic confirmation using a 21e Western blot. A detailed analysis (serologic, molecular, and virologic), based on a laboratory diagnostic algorithm for characterization of HTLV-1 and HTLV-2 infections was undertaken in 50 seropositive or seroindeterminate blood donors. Modified serologic assays (2.3 Western blot that incorporate type-specific recombinant peptides) performed in 29 HTLV-1/2 positive and 21 HTLV-1/2 indeterminate donors with the 21e Western blot identified 25 as infected with HTLV-1, four with HTLV-2, five with untypable HTLV-1/2, 15 as HTLV-1/2 indeterminate, and one as seronegative. Polymerase chain reaction (PCR) analysis using DNA amplification of proviral pol and tax sequences from peripheral blood mononuclear cells confirmed HTLV-1 and HTLV-2 infections in all 2.3 Western blot seropositive donors; of the five serologically untypable donors, three were confirmed to be HTLV-1 positive, one HTLV-2 positive, and one negative by PCR. All of the seroindeterminate donors were also negative by PCR. Furthermore, HTLV-1 could be isolated in cocultures from 10 of 18 infected donors. Cell lines developed from two HTLV-1-infected donors were of T cell phenotype (CD2+, CD3+), exhibiting surface markers of activated CD4 cells (CD4+ CD25+ HLA-DR+). Thus, we provide evidence for the high seroprevalence of HTLV infection in blood donor population in Sao Paulo, Brazil compared with North American donors and propose a comprehensive serologic and genotypic diagnostic algorithm for HTLV-infected donors that has strong implications for counseling of these individuals.
authors.affiliation: Department of Infectious Diseases, School of Medicine, University of Sao Paulo, Brazil.
authors.forename: A A
authors.initials: AA
authors.lastname: Segurado
authors.forename: C M
authors.initials: CM
authors.lastname: Malaque
authors.forename: L M
authors.initials: LM
authors.lastname: Sumita
authors.forename: C S
authors.initials: CS
authors.lastname: Pannuti
authors.forename: R B
authors.initials: RB
authors.lastname: Lal
mesh_terms: D015703:Antigens, CD / Q000276:immunology; D001782:Blood Donors; D015153:Blotting, Western; D001938:Brazil / Q000453:epidemiology; D002478:Cells, Cultured; D017931:DNA Primers / Q000235:genetics; D016355:Genes, pX; D015751:Genes, pol; D006684:HLA-DR Antigens / Q000276:immunology; D015481:HTLV-I Antibodies / Q000032:analysis; D015486:HTLV-I Antigens / Q000032:analysis / Q000276:immunology; D015490:HTLV-I Infections / Q000175:diagnosis* / Q000453:epidemiology; D015482:HTLV-II Antibodies / Q000032:analysis; D015487:HTLV-II Antigens / Q000032:analysis / Q000276:immunology; D015491:HTLV-II Infections / Q000175:diagnosis* / Q000453:epidemiology; D015368:Human T-lymphotropic virus 1 / Q000276:immunology / Q000302:isolation & purification; D015367:Human T-lymphotropic virus 2 / Q000276:immunology / Q000302:isolation & purification; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000821:virology; D016133:Polymerase Chain Reaction; D011533:Proviruses / Q000235:genetics; D011994:Recombinant Proteins / Q000276:immunology; D016036:Seroepidemiologic Studies; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D015703:Antigens, CD; D017931:DNA Primers; D006684:HLA-DR Antigens; D015481:HTLV-I Antibodies; D015486:HTLV-I Antigens; D015482:HTLV-II Antibodies; D015487:HTLV-II Antigens; D011994:Recombinant Proteins