title: Absence of HTLV-I/II infection in blood donors with positive and inconclusive HTLV-I/II serology.
abstract: The pathogenetic potential and the true extent of human T leukemia/lymphotropic virus type I (HTLV-I) and type II (HTLV-II) infection are unknown. To find out more about HTLV-I/II seroepidemiology and the risks of iatrogenic transmission, we performed a serological study, screening 4086 healthy blood donors. A surprisingly high percentage of serum reactivity to HTLV-I/II antigens was observed by commercial ELISA (2.08%) and immunoblotting (IB) (0.85%) analysis, although none of the samples satisfied the (IB) criteria for positivity based on detection of gag protein p24 and at least one env gene product, either gp46 or gp61/68. To clarify these inconclusive results, we performed polymerase chain reaction (PCR) analysis for HTLV-I and HTLV-II provirus detection in peripheral blood lymphocytes, obtained from individuals with an apparent pattern of seropositivity. The data obtained by PCR failed to reveal evidence of HTLV-I/II provirus integration in peripheral blood cells, ruling out the possibility of a viral infection in these cases, and pinpointing the limitations of both serological methods used. Our observations suggest that serological assays alone are not a reliable tool for blood donor screening of HTLV-I/II infection and raise the important question of interpreting inconclusive results.
authors.affiliation: Institute of Microbiology, University of Bologna, Italy.
authors.forename: M C
authors.initials: MC
authors.lastname: Re
authors.forename: G
authors.initials: G
authors.lastname: Furlini
authors.forename: E
authors.initials: E
authors.lastname: Ramazzotti
authors.forename: M
authors.initials: M
authors.lastname: Vignoli
authors.forename: G
authors.initials: G
authors.lastname: Zauli
authors.forename: S
authors.initials: S
authors.lastname: Lolli
authors.forename: P
authors.initials: P
authors.lastname: Monari
authors.forename: D
authors.initials: D
authors.lastname: Belletti
authors.forename: A
authors.initials: A
authors.lastname: Nanetti
authors.forename: M
authors.initials: M
authors.lastname: La Placa
mesh_terms: D001483:Base Sequence; D001782:Blood Donors; D017977:Deltaretrovirus / Q000302:isolation & purification; D015481:HTLV-I Antibodies / Q000097:blood; D015486:HTLV-I Antigens / Q000097:blood; D015490:HTLV-I Infections / Q000453:epidemiology*; D015491:HTLV-II Infections / Q000453:epidemiology*; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008214:Lymphocytes / Q000382:microbiology; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D016036:Seroepidemiologic Studies
chemical_list: D015481:HTLV-I Antibodies; D015486:HTLV-I Antigens