Sensitivity and specificity of four assays to detect human T− lymphotropic virus type I or type I/II antibodies

Abstract

Background: Assays that detect human T‐lymphotropic virus type I and type II antibody (HTLV‐I/II) are widely used in the routine screening of blood donors. Study Design and Methods: Four commercially available anti‐HTLV‐I (Fujirebio and Organon Teknika) or ‐HTLV‐I/II assays (Murex and Ortho) were evaluated in various serum panels: A) HTLV‐I‐positive specimens (n = 41), confirmed by Western blot and polymerase chain reaction; B) a commercially available anti‐HTLV‐I/II panel; C) serial dilutions of sera from HTLV‐I‐positive individuals (n = 30), confirmed by immunofluorescence assay and Western blot: D) serial dilutions of HTLV‐II‐positive blood donors (n = 20), confirmed by Western blot and polymerase chain reaction, and E) sera from first‐time blood donors (n = 1055). Results: All four assays elicited reactions in all 82 HTLV‐I‐ positive samples in Panels A, B, and C. Of 32 HTLV‐II‐positive specimens in Panels B and D, 31 (96.9%) reacted in the Organon Teknika assay and all 32 reacted in the remaining tests. Probit analysis of test results in Panels C and D indicated that the Fujirebio test was the most sensitive assay, followed by Organon Teknika, Ortho, and Murex. The specificities of Fujirebio, Murex, Organon Teknika, and Ortho tests in 1055 first‐time blood donors were 99.9, 100, 99.6, and 99.9 percent, respectively. Conclusion: All four studied assays for detecting HTLV‐I or HTLV‐I/II antibodies are appropriate as screening tests.