Failure to isolate human T cell lymphotropic virus type I and to detect variant-specific genomic sequences by polymerase chain reaction in Melanesians with indeterminate Western immunoblot

Serological, Epidemiological, and Molecular Differences between Human T-Cell Lymphotropic Virus Type 1 (HTLV-1)-Seropositive Healthy Carriers and Persons with HTLV-I Gag Indeterminate Western Blot Patterns from the Caribbean

“…Blood Banks). Although our survey disclosed several different indeterminate WB patterns, the leading one among local blood donors was the HGIP, previously described in Cameroon (26,28), other African countries (11,42,44), and Melanesia (20,31). Among all the HTLV-indeterminate patterns, the frequency of HGIP in Guadeloupe was particularly high regardless of the WB version used (more than 40% for both WB2.3 and WB2.4).…”

“…This high frequency of indeterminate results clearly emphasizes the difficulty in assessing the real HTLV-1 seroprevalence, especially in tropical areas where indeterminate WB patterns peak and lead to misclassification. As a consequence, many earlier studies, particularly those performed in Africa but also in the Caribbean, have probably overestimated the HTLV-1 seroprevalences (2,4,6,11,12,13,15,19,20,31).…”

“…Indeed, this technique did not detect HTLV-1 sequences in the PBMC of 13 tested HGIP persons. It must be pointed out that the majority of previous studies, performed in various areas, also failed to detect HTLV-1 proviral sequences, even by the use of highly conserved HTLV-1 and HTLV-2 primers on fresh or cultured PBMCs of those individuals presenting an HTLV indeterminate WB pattern (15,18,22,26,31,44). However, a recent report has described the amplification of an HTLV-1 tax sequence from patients with neurological disease exhibiting an HGIP WB reactivity.…”

“…Stringent HTLV WB criteria require that an HTLV-1-infected individual have an antibody response to the complete range of the core bands (p19, p24, and pr53), in addition to the respective recombinant glycoprotein (gd21) and to type-specific synthetic peptide MTA-1 (HTLV-1). However, especially in tropical areas, indeterminate HTLV serologic test results (i.e., WB patterns reactive to only part of the viral proteins) appear commonly, leading to difficulties in interpretation and counseling (2,6,11,12,13,15,16,18,19,20,23,26,28,31,37,38,44). Previous epidemiological studies, particularly in Cameroon (central Africa), have reported that indeterminate WB patterns (notably those exhibiting p19, p26, p28, p32, p36, and pr53, which have been termed the HTLV-1 Gag indeterminate profile [HGIP]) were not associated with true HTLV-1 infection (26,28).…”

Monographs on the Evaluation of Carcinogenic Risks to Humans

“…Furthermore, sporadic cases of HTLV-I infection have been reported in Iraq (Denic et aL., 1990) and Kuwait (Voevodin et al, 1995). ln the Pacific region, isoIated clusters of HTL V -1 have been described, especially in two tribes of Papua New Guinea (Garrto et al, 1990;Yanagihara et al, 1990;LaI et al, 1992c;Nerurkar et al, 1992;Yanagihara, 1994) and in the Australian AboriginaI population (Mayet aL., 1988;Bastian et al, 1993;Bolton et aL., 1994). Furthermore, HTLV-I is endemic in the Solomon Islands Yanagihara et al, 1991), but seems very rare in most other Pacific islands .…”