title: Reevaluation of confirmatory tests for human T-cell leukemia virus Type 1 using a luciferase immunoprecipitation system in blood donors.
abstract: BACKGROUND
  Recently, Japanese Red Cross blood centers have changed the confirmatory test method from an indirect immunofluorescence (IF) technique to Western blotting (WB) for antibodies against human T-cell leukemia virus Type 1 (HTLV-1). In this study, these HTLV-1 tests were assessed using another sensitive method, that is, a luciferase immunoprecipitation system (LIPS), to identify a better confirmatory test for HTLV-1 infection.
  
  
  METHODS
  Plasma samples from 54 qualified donors and 114 HTLV-1 screening-positive donors were tested by LIPS for antibodies against HTLV-1 Gag, Tax, Env, and HBZ recombinant proteins. The donors were categorized into six groups, namely, (Group I) qualified donors, screening positive; (Group II) IF positive; (Group III) IF negative; (Group IV) WB positive; (Group V) WB negative; and (Group VI) screening positive in the previous blood donation, but WB-indeterminate during this study period.
  
  
  RESULTS
  In Groups II and IV, all plasma samples tested positive by LIPS for antibodies against Gag and Env proteins. In Group V, all samples tested negative by LIPS, whereas some Group III samples reacted with single or double antigens in LIPS. In Group VI, the LIPS test identified a donor with suspected HTLV-1 infection. The first case of a blood donor with plasma that reacted with HBZ was identified by LIPS.
  
  
  CONCLUSIONS
  Reevaluation of the current HTLV-1 screening method using the LIPS test showed that both confirmatory tests had similar sensitivity and specificity only when WB indeterminate results were eliminated. LIPS is a promising method for detecting and characterizing HTLV-1 antibodies.
authors.affiliation: Japanese Red Cross, Kinki Block Blood Center, Osaka, Japan.
authors.forename: Rika A
authors.initials: RA
authors.lastname: Furuta
authors.affiliation: Laboratory of Virus Control, Institute for Virus Research, Kyoto University, Kyoto, Japan.
authors.forename: Guangyong
authors.initials: G
authors.lastname: Ma
authors.affiliation: Laboratory of Virus Control, Institute for Virus Research, Kyoto University, Kyoto, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Matsuoka
authors.affiliation: Japanese Red Cross, Kinki Block Blood Center, Osaka, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Otani
authors.affiliation: Japanese Red Cross, Kinki Block Blood Center, Osaka, Japan.
authors.forename: Harumichi
authors.initials: H
authors.lastname: Matsukura
authors.affiliation: Japanese Red Cross, Kinki Block Blood Center, Osaka, Japan.
authors.forename: Fumiya
authors.initials: F
authors.lastname: Hirayama
mesh_terms: D050976:Basic-Leucine Zipper Transcription Factors / Q000276:immunology; D001782:Blood Donors; D058731:Blood Safety / Q000379:methods*; D015153:Blotting, Western; D046148:Donor Selection / Q000331:legislation & jurisprudence / Q000379:methods*; D004797:Enzyme-Linked Immunosorbent Assay; D005188:False Negative Reactions; D005189:False Positive Reactions; D017930:Genes, Reporter; D005822:Genetic Vectors; D057809:HEK293 Cells; D015481:HTLV-I Antibodies / Q000097:blood*; D015486:HTLV-I Antigens / Q000235:genetics / Q000276:immunology; D015490:HTLV-I Infections / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology / Q000517:prevention & control / Q000821:virology; D015368:Human T-lymphotropic virus 1 / Q000276:immunology / Q000302:isolation & purification*; D006801:Humans; D047468:Immunoprecipitation; D007564:Japan / Q000453:epidemiology; D049410:Luciferases, Renilla / Q000032:analysis / Q000235:genetics; D008163:Luminescent Measurements; D011237:Predictive Value of Tests; D012191:Retroviridae Proteins / Q000276:immunology; D012680:Sensitivity and Specificity; D014766:Viremia / Q000175:diagnosis* / Q000821:virology
chemical_list: D050976:Basic-Leucine Zipper Transcription Factors; C479751:HBZ protein, human T-cell leukemia virus type I; D015481:HTLV-I Antibodies; D015486:HTLV-I Antigens; D012191:Retroviridae Proteins; D049410:Luciferases, Renilla