Markers of health status in an HTLV-I-positive cohort

The health effects of chronic human T-cell lymphotropic virus type I (HTLV-I) infection were examined in a cohort of Japanese men who had emigrated from Okinawa, Japan, and had been participants in a prospective study in Hawaii since 1965. In the present follow-up study carried out in 1987-1988, various health indicators were measured in the subjects, whose mean age was 72.5 years. Participation rates were lower in the HTLV-I seropositives than in the seronegatives (46.7% vs. 76.0%) in the ≥75-year age group. Lack of participation was significantly correlated with a high HTLV-I antibody titer. Among the participants, seropositive subjects were significantly more likely than the seronegatives to have lymphocytopenia (32.7% vs. 17.7%) and mild anemia (25.5% vs. 14.1%) after adjustment for age and socioeconomic status. The seropositives also had a higher frequency of acupuncture therapy (age-adjusted odds ratios were 2.1 and 4.2 for 1-5 treatments and ≥6 treatments, respectively). Proportions of subjects who had been hospitalized at least twice were higher among the seropositives in the oldest age groups, 70-74 years and ≥75 years, but not in those aged 65-69 years. Although specific disease conditions were not identified in this study, hematologic data, treatment histories, and the correlation between participation status and HTLV-I antibody titers suggest that chronic HTLV-I infection may be associated with as yet undefined adverse health effects, particularly in older age groups. Am J Epidemiol 1992; 136: 1349-57.