THE DISTRIBUTION OF T-CELL SUBSETS AMONG HTLV-I CARRIERS IN JAPAN

Data on T-cell subsets from 89 human T-cell lymphotropic virus-I (HTLV -I) carriers and 25 seronegative people were analyzed to identify diff erences in T-cell subset values among three subgroups: HTLV-I carriers with abnormal lymphocytes (Ably; n = 24), carriers without Ably (n = 65), and HTLV-I seronegatives (n = 25). Estimates of mean values were adjusted for age, sex, smoking, and alcohol drinking, as appropriate. The percentage of CD25(+) T cells was elevated in carriers with Ably ( mean, 16.7 +/- 1.0) compared with the seronegatives (11.4 +/- 1.4; p = 0.0002); individuals with CD25 T-cell percentages above the median fo r the seronegatives had a corresponding 5.4-fold risk for being a carr ier with Ably. Similarly, the percentage of CD4 T cells was elevated i n carriers with Ably. Conversely, the percentage of CDS T cells was lo wer among both groups of HTLV-I carriers than in the seronegatives. Th ere was a corresponding significant increase (p = 0.0004) of the CD4/C D8 ratio among carriers with Ably (1.57 +/- 0.12) compared with the se ronegatives (1.22 +/- 0.12). Among subjects with CD4/CD8 ratios above the median for the seronegatives, there were 6.8- and 4.5-fold risks f or being carriers with or without Ably, respectively. The percentage o f CD7 was lower among carriers with Ably (75.6 +/- 1.6) than among ser onegatives (78.9 +/- 1.5; p = 0.13). The percentage of beta-interleuki n-2-receptor-positive T cells did not vary among the three subgroups. The results indicate that levels of CD25 and CD4 cells are increased a mong HTLV-I carriers, with the largest increase seen in carriers with Ably. Aside from changes in T-cell percentages due to clonal expansion of infected cells, altered cytokine production in response to HTLV-I infection may mediate changes in T-cell populations.