Strategies for diagnosis of HTLV-I and -II.
BACKGROUND
No gold standard exists for diagnosis of HTLV infection. The aim of thus study was to compare the accuracy of a combination of two sensitive ELISAs with Western blot (WB), a line immunoassay, and PCR for diagnosis of HTLV infection.


METHODS
Nine hundred eighty-five specimens were tested for the presence of HTLV antibodies by HTLV-I and/or HTLV-II EIAs (Murex and Ortho), WB (Diagnostic Biotechnology), line immunoassay (INNO-LIA, Innogenetics), and/or presence of HTLV DNA by PCR. The results were compared with the probable HTLV infection status of each subject, as determined by detailed review of all available laboratory, clinical, and epidemiologic data.


RESULTS
The sensitivity for diagnosis of HTLV-I infection was high for all assays evaluated, but both PCR and WB had a lower sensitivity rate (approx., 80%) for confirmation of HTLV-II. INNO-LIA detected 94 percent of the HTLV-II-positive samples. However, Murex EIA in combination with Ortho EIA was 100-percent sensitive for the detection of both HTLV-I and HTLV-II antibodies. Furthermore, the number of samples giving indeterminate results in the ELISA combination was much lower as compared with WB (2.5% vs. 50%).


CONCLUSIONS
Based on these findings, a new, more sensitive and specific test strategy for HTLV diagnosis than the current algorithm, which includes WB, is proposed. Thereby, both the direct and indirect costs can be substantially reduced.
Thorstensson
Rigmor
R
Department of Immunology, Swedish Institute for Infectious Disease Control, Solna, Sweden. rigmor.thorstensson@smi.ki.se
Albert
Jon
J
Andersson
Sören
S
D000465:Algorithms; D015153:Blotting, Western / Q000191:economics; D003363:Cost Control; D004279:DNA, Viral / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay / Q000191:economics; D015481:HTLV-I Antibodies / Q000097:blood; D015490:HTLV-I Infections / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology; D015482:HTLV-II Antibodies / Q000097:blood; D015491:HTLV-II Infections / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology; D015368:Human T-lymphotropic virus 1 / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D015367:Human T-lymphotropic virus 2 / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D006801:Humans; D007118:Immunoassay / Q000191:economics; D007963:Leukocytes, Mononuclear / Q000821:virology; D008403:Mass Screening / Q000191:economics / Q000379:methods; D016133:Polymerase Chain Reaction / Q000191:economics; D011446:Prospective Studies; D011533:Proviruses / Q000302:isolation & purification; D012367:RNA, Viral / Q000097:blood; D012680:Sensitivity and Specificity; D013548:Sweden / Q000453:epidemiology; D014766:Viremia / Q000175:diagnosis* / Q000453:epidemiology
D004279:DNA, Viral; D015481:HTLV-I Antibodies; D015482:HTLV-II Antibodies; D012367:RNA, Viral