title: Evaluation of a p21e-spiked western blot (immunoblot) in confirming human T-cell lymphotropic virus type I or II infection in volunteer blood donors. The Retrovirus Epidemiology Donor Study Group.
abstract: Current algorithms for the serologic confirmation of human T-cell lymphotropic virus type I and II (HTLV-I/II) antibody reactivity are complicated. We evaluated the performance of an HTLV-I Western blot (immunoblot) spiked with recombinant p21e protein (p21e WB) as an alternative to current confirmatory methods. These methods include the HTLV-I viral lysate Western blot and either a radioimmunoprecipitation assay or a p21e enzyme-linked immunosorbent assay. Five hundred fifty nine blood donations obtained from five U.S. blood centers and classified as HTLV-I/II seropositive (n = 149) or seroindeterminate (n = 410) by routine testing methods were further evaluated by PCR for proviral DNA and by the p21e WB. On the basis of serologic and PCR testing, 155 donations were classified as HTLV-I/II infected. The sensitivity of the p21e WB was 97.4%, slightly exceeding that of routine confirmatory testing. The specificity of the p21e WB was 97.5%, as determined by testing of 404 seroindeterminate samples that were negative in the PCR. The positive predictive value of the p21e WB was 94%. In contrast, the specificity and positive predictive value of routine confirmatory testing were both 100%. Follow-up sampling of presumptive p21e WB false-positive donors substantiated the absence of HTLV-I/II infection. Although the p21e WB used in this study has high sensitivity and may be useful as a confirmatory assay in epidemiologic research studies, it may not be ideal as a confirmatory test for the notification of blood donors.
authors.affiliation: Southern California Region American Red Cross Blood Services, Los Angeles 90006.
authors.forename: S H
authors.initials: SH
authors.lastname: Kleinman
authors.forename: J E
authors.initials: JE
authors.lastname: Kaplan
authors.forename: R F
authors.initials: RF
authors.lastname: Khabbaz
authors.forename: M A
authors.initials: MA
authors.lastname: Calabro
authors.forename: R
authors.initials: R
authors.lastname: Thomson
authors.forename: M
authors.initials: M
authors.lastname: Busch
mesh_terms: D001782:Blood Donors; D015153:Blotting, Western / Q000379:methods* / Q000706:statistics & numerical data; D004279:DNA, Viral / Q000097:blood / Q000235:genetics; D005069:Evaluation Studies as Topic; D015686:Gene Products, env / Q000276:immunology; D015481:HTLV-I Antibodies / Q000097:blood; D015486:HTLV-I Antigens; D015490:HTLV-I Infections / Q000175:diagnosis* / Q000276:immunology / Q000382:microbiology; D015482:HTLV-II Antibodies / Q000097:blood; D015491:HTLV-II Infections / Q000175:diagnosis* / Q000276:immunology / Q000382:microbiology; D015368:Human T-lymphotropic virus 1 / Q000235:genetics; D015367:Human T-lymphotropic virus 2 / Q000235:genetics; D006801:Humans; D015682:Retroviridae Proteins, Oncogenic / Q000276:immunology; D012680:Sensitivity and Specificity; D054299:env Gene Products, Human Immunodeficiency Virus
chemical_list: D004279:DNA, Viral; D015686:Gene Products, env; D015481:HTLV-I Antibodies; D015486:HTLV-I Antigens; D015482:HTLV-II Antibodies; D015682:Retroviridae Proteins, Oncogenic; D054299:env Gene Products, Human Immunodeficiency Virus; C055265:gp21 protein, Human T-lymphotropic virus 1