Use of a generic polymerase chain reaction assay detecting human T-lymphotropic virus (HTLV) types I, II and divergent simian strains in the evaluation of individuals with indeterminate HTLV serology.
In countries with a low prevalence of human T-lymphotropic virus (HTLV) infection, indeterminate HTLV serologies are a major problem in blood bank screening because of the uncertainties about infection in these cases. The recent discovery of two new types of simian T-lymphotropic viruses (STLV), which give an HTLV-indeterminate serology, raises the question whether indeterminate serologies in humans may be linked to new types of HTLV. Starting from a Tax sequence alignment of all available primate T-cell lymphotropic virus strains (PTLV), including the two new types STLV-PH969 and STLV-PP1664, we developed generic and type-specific nested polymerase chain reactions (PCRs). The generic PCR proved to be highly sensitive and cross-reactive for all four types of PTLV, while the discriminatory PCRs had a high sensitivity and a specificity of 100%. There was no cross-reactivity with human immunodeficiency virus (HIV), ensuring correct interpretation of results from coinfected patients. Among the 77 serologically indeterminate samples tested, 6 were found to be HTLV-1 PCR positive and 1 was HTLV-II PCR positive. Sequencing of one of the HTLV-I PCR positives excluded PCR contamination, and revealed a divergent type of HTLV-I. The majority of the seroindeterminate samples (91%) were however HTLV-PCR negative, and no new types of HTLV were found. This new assay can identify otherwise undetected HTLV-I or HTLV-II infections and is a useful tool of screening for new types of HTLV among seroindeterminate samples.
Vandamme
A M
AM
Rega Institute for Medical Research and University Hospitals, Katholieke Universiteit Leuven, Belgium.
Van Laethem
K
K
Liu
H F
HF
Van Brussel
M
M
Delaporte
E
E
de Castro Costa
C M
CM
Fleischer
C
C
Taylor
G
G
Bertazzoni
U
U
Desmyter
J
J
Goubau
P
P
D000818:Animals; D006800:Deltaretrovirus Infections / Q000097:blood / Q000175:diagnosis* / Q000235:genetics*; D003937:Diagnosis, Differential; D015368:Human T-lymphotropic virus 1 / Q000737:chemistry / Q000145:classification / Q000235:genetics*; D015367:Human T-lymphotropic virus 2 / Q000737:chemistry / Q000145:classification / Q000235:genetics*; D006801:Humans; D002679:Pan troglodytes; D010215:Papio; D016133:Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000379:methods; D015303:Simian T-lymphotropic virus 1 / Q000737:chemistry / Q000145:classification / Q000235:genetics*; D013045:Species Specificity