Evaluation of a new screening assay for HTLV‐1 and ‐2 antibodies for large‐scale use

Abstract

Laboratory testing for Human T‐lymphotropic Virus type 1 and 2 (HTLV‐1 and ‐2) infections has become routine in blood transfusion, tissue transplantation and clinical diagnoses in many countries worldwide. Screening is usually based on the detection of antibodies to HTLV‐1 and/ or ‐2. The number of commercially available assays is limited, and among them, ELISA tests based on microtiter format are most commonly used. Recently, the new rHTLV‐I/II assay (Abbott Laboratories, Abbott Park, IL) was released; this assay was developed for an automatic large‐scale screening platform. This assay was evaluated using pre‐characterized serum panels and routine samples from the clinical laboratory. The sensitivity was 100% for HTLV‐1 and ‐2 (99/99 and 42/42, respectively, including one sample that was dually reactive, HTLV‐1 + 2). To test assay specificity, panels of blood donor sera, specimens from patients with autoimmune diseases and some viral infections were used. False‐reactive samples from previous HTLV diagnoses were also included. With these panels, the specificity was 99.4% (619/623). However, the four false‐reactive samples all belonged to the group of samples that were previously considered as false‐reactive for HTLV‐antibodies. All other samples were negative by the rHTLV‐I/II assay, and thus 100% specificity was obtained. The 1,412 samples tested in the clinic by this assay in routine use were all negative (100% specificity). Taken together, the overall specificity was 99.8%. The assay was sensitive, specific and appropriate for the large‐scale screening of samples for HTLV‐1/2 antibodies. J. Med. Virol. 82:1606–1611, 2010. © 2010 Wiley‐Liss, Inc.

Evaluation of Sensitivity and Specificity Performance of Elecsys HTLV-I/II Assay in a Multicenter Study in Europe and Japan

“…Laboratory screening for HTLV-1/2 infection has become routine for blood donors in developed and some developing countries where the virus is endemic or where blood donors are considered to be at risk of infection (17, 18, 29). In low-seroprevalence populations, the positive predictive power of any assay is low and most positive results are false positives (4).…”

A New and Frequent Human T-Cell Leukemia Virus Indeterminate Western Blot Pattern: Epidemiological Determinants and PCR Results in Central African Inhabitants

“…Screening tests are usually enzyme-linked immunoassorbent assays (ELISAs) (3,5,18,43,66) or particle agglutination (PA) (33). Confirmatory tests are immunofluorescence (IF) (23) but mostly Western blot (WB) analyses (30,35,38,39,64,71).…”

HTLV-1 in Solid-Organ Transplantation

“…Over the last two decades, laboratory testing for HTLV-1/2 infections has become routine in blood transfusion, solidorgan/tissue transplantation, and clinical diagnoses in many countries in the world (29). Screening is based on the detection of HTLV antibodies, which develop 1 to 3 months after exposure to HTLV infection and persist for life (4).…”

“…In contrast, Kaul et al calculated that approximately 135 to 195 healthy organs (45Y60 donors) are being wasted annually in the United States as a result of false-positive tests with existing screening tools (42). Other HTLV-1/2 assays are commercially available (29), including the Avioq HTLV-I/II Microelisa System (www.avioq.com), which as of March 2012 became the second Food and Drug AdministrationYlicensed assay. The validity of both new and older assays is limited by the fact that they are designed for high-throughput blood screening and not single-sample analysis, which is essential to achieve the rapid turnaround times that are required in organ donation.…”