HIGH PREVALENCE OF ARTHROPATHY IN HTLV-I CARRIERS ON A JAPANESE ISLAND

Objective-To determine the aetiological relationship between human T c ell leukaemia virus type-I (HTLV-I) and arthritis, by performing an ep idemiological study of the inhabitants of Tsushima, an island northwes t of the main island of Kyushu, japan, which is an endemic area of HTL V-I. Methods-A total of 7087 people underwent an annual health check, and those with arthropathy had further physical and radiological exami nations by rheumatologists. The presence of HTLV-I antibody was determ ined by the particle agglutinin method, and integration of the provira l DNA in peripheral lymphocytes was confirmed by polymerase chain reac tion. Results-HTLV-I was positive in 26.1% of inhabitants; the inciden ce increased to 37.0% in patients with symptoms of polyarthritis. The prevalence of rheumatoid arthritis (RA) was significantly different be tween HTLV-I carriers (0.56%) and non-carriers (0.31%). The stage of b one destruction in HTLV-I carriers with articular symptoms was milder than that in RA patients without HTLV-I. The relative risk of HTLV-I i nfection for polyarthritis was 1.66 (p < 0.05). Conciusion-This is the first epidemiological report clarifying the association between HTLV- I and polyarthritis. Our results suggest that this viral infection has a relationship to RA.