HTLV‐I/II Seroindeterminate Western Blot Reactivity in a Cohort of Patients with Neurological Disease

Abstract

The human T-cell lymphotropic virus type I (HTLV-I) is associated with a chronic, progressive neurological disease known as HTLV-I-associated myelopathy/tropical spastic paraparesis. Screening for HTLV-I involves the detection of virus-specific serum antibodies by EIA and confirmation by Western blot. HTLV-I/II seroindeterminate Western blot patterns have been described worldwide. However, the significance of this blot pattern is unclear. We identified 8 patients with neurological disease and an HTLV-I/II seroindeterminate Western blot pattern, none of whom demonstrated increased spontaneous proliferation and HTLV-I-specific cytotoxic T lymphocyte activity. However, HTLV-I tax sequence was amplified from the peripheral blood lymphocytes of 4 of them. These data suggest that patients with chronic progressive neurological disease and HTLV-I/II Western blot seroindeterminate reactivity may harbor either defective HTLV-I, novel retrovirus with partial homology to HTLV-I, or HTLV-I in low copy number.

Cross-Reactive Antibodies to Target Proteins are Dependent upon Oligomannose Glycosylated Epitopes in HTLV-1 Associated Neurological Disease

“…1E, lane 2). The anti-HTLV-1-p24-(gag) antibody also immunoreacted with a band at 53 kDa, consistent with HTLV-1-p24-(gag) being part of the HTLV-1-p53-(gag) protein [31][32][33]. The bands at 19, 21, and 28 kDa (Fig.…”

Characterization and Sequencing of Prototypic Human T-Lymphotropic Virus Type 1 (HTLV-1) from an HTLV-1/2 Seroindeterminate Patient

“…Antibodies to HTLV-1 antigens were not detectable at the 1:160,000 dilution. At no dilution do any of these patterns resemble the Western blot pattern of patient SI-1 or the other seroindeterminate patterns previously described and typified by reactivity to p19 and absence of rgp46, p24, and rgp21 (17).…”

“…We have previously described a cohort of patients with various neurological symptoms and seroindeterminate HTLV-1/2 Western blot profiles (17). Analysis of PBL from these individuals reflected data generated by other groups (9,10,12).…”

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

“…However, a recent report has described the amplification of an HTLV-1 tax sequence from patients with neurological disease exhibiting an HGIP WB reactivity. This suggests that this seroindeterminate WB pattern might be associated in some rare cases with defective HTLV-1 strains or with a novel retrovirus having homology with HTLV-1, or finally with slowly replicating HTLV-1 (39,47). In addition, it seems unlikely that the HGIP may represent a delayed or slow seroconversion, because most of our followed-up subjects did not show any evolution of their WB profile over time and because the minority who did became EIA negative.…”