Human T-lymphotropic virus type-I infection, antibody titers and cause-specific mortality among atomic-bomb survivors.
There have been few longitudinal studies on the long-term health effects of human T-lymphotropic virus type-I (HTLV-I) infection. The authors performed a cohort study of HTLV-I infection and cause-specific mortality in 3,090 atomic-bomb survivors in Nagasaki, Japan, who were followed from 1985-1987 to 1995. The prevalence of HTLV-I seropositivity in men and women was 99/1,196 (8.3%) and 171/1,894 (9.0%), respectively. During a median follow-up of 8.9 years, 448 deaths occurred. There was one nonfatal case of adult T-cell leukemia/lymphoma (incidence rate = 0.46 cases/1,000 person-years; 95% confidence interval [CI] 0.01-2.6). After adjustment for sex, age and other potential confounders, significantly increased risk among HTLV-I carriers was observed for deaths from all causes (rate ratio [RR] = 1.41), all cancers (RR = 1.64), liver cancer (RR = 3.04), and heart diseases (RR = 2.22). The association of anti-HTLV-I seropositivity with mortality from all non-neoplastic diseases (RR = 1.40) and chronic liver diseases (RR = 5.03) was of borderline significance. Possible confounding by blood transfusions and hepatitis C/B (HCV/HBV) viral infections could not be precluded in this study. However, even after liver cancer and chronic liver diseases were excluded, mortality rate was still increased among HTLV-I carriers (RR = 1.32, 95% CI 0.99-1.78), especially among those with high antibody titers (RR = 1.56, 95% CI 0.99-2.46, P for trend = 0.04). These findings may support the idea that HTLV-I infection exerts adverse effects on mortality from causes other than adult T-cell leukemia/lymphoma. Further studies on confounding by HCV/HBV infections and the interaction between HCV/HBV and HTLV-I may be required to analyze the increased mortality from liver cancer and chronic liver diseases.
Department of Epidemiology, Radiation Effects Research Foundation, Nagasaki.
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Arisawa
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Soda
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Akahoshi
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Matsuo
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Nakashima
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Tomonaga
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Saito
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002423:Cause of Death; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D015481:HTLV-I Antibodies / Q000097:blood*; D015490:HTLV-I Infections / Q000097:blood / Q000276:immunology* / Q000401:mortality*; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000401:mortality; D009689:Nuclear Warfare; D012680:Sensitivity and Specificity; D012737:Sex Factors
D015481:HTLV-I Antibodies