Elevated levels of soluble adhesion molecules in sera and BAL fluid of individuals infected with human T-cell lymphotropic virus type 1

Study objective: T-lymphocytic alveolitis and increased levels of interleuk in-2 receptor-alpha. (CD25)-bearing T cells in the BAL fluid (BALF) of huma n T-cell lymphotropic virus type 1 (HTLV-1) carriers have been reported. Se veral chemokines and adhesion molecules may contribute to the accumulation of T lymphocytes in the lungs of HTLV-1 carriers. To clarify the correlatio n between adhesion molecules and HTLV-1-associated pulmonary disorders, we compared the distribution of T-lymphocyte subsets and soluble adhesion mole cules, including soluble intercellular adhesion molecule (sICAM)-1, soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble L-selectin (sL-select in), soluble E-selectin (sE-selectin), and soluble P-selectin (sP-selectin) , in BALF and peripheral blood, between HTLV-1 carriers and noninfected hea lthy subjects. Design: Flow cytometric analysis with monoclonal antibodies to cell-surface antigens was used to identify T-lymphocyte subsets in BALF samples from HT LV-1 carriers (n = 13) and noninfected healthy control subjects (n = 10). T he levels of various soluble adhesion molecules in serum and in BALF mere e stimated by enzyme-linked immunosorbent assay. Results: Higher percentages of CD3+ cells, CD3-expressing human leukocyte a ntigen-DR antigen, and CD3+CD25+ cells were detected in the BALF of HTLV-1 carriers than in that of noninfected control subjects, The concentrations o f sICAM-1, sVCAM-1, sL-selectin, SE- selectin, and sP-selectin in the sera of patients were significantly higher than those in noninfected healthy con trol subjects. The concentration of sICAM-1 in the BALF of patients was sig nificantly higher than that in noninfected healthy control subjects, and th e concentration of sICAM-1 correlated well with the percentage of CD3+CD25 cells. Conclusion: The concentrations of adhesion molecules in the sera of and sIC AM-1 in the BALF of HTLV-1 carriers were significantly higher than those in noninfected individuals, and the concentration of sICAM-1 correlated well with the percentage of CD3+CD25+ cells in BALF. Our results suggest a possi ble interaction between activated T cells bearing CD25 and soluble adhesion molecules, especially sICAM-1, which may contribute to the pulmonary invol vement in HTLV-1 carriers.