Thirty-one patients with lung cancer in Okinawa known as HTLV-Ⅰendemic area, and 140 patients in Okayama were evaluated in regard to HTLV-Ⅰinfection and iterstitial pulmonary shadows. The presence of HTLV-Ⅰinfection was examined by the polymerase chain reaction (PCR) method in peripheral blood mononuclear cells, and indirect immunofluorescent (IF) assay in sera. Interstitial pulmonary shadows on the chest roentgenograph, were classified according to the grade of fibrosis. The rate of HTLV-Ⅰinfection in patients with lung cancer was higher than that in healthy controls by IF assay in both districts. The rate of anti-HTLV-Ⅰantibody was higher in lung cancer patients with severe fibrosis than in those with milder fibrosis, but the grade of fibrosis and existence of pX gene had no relation in Okinawa or in Okayama. The incidence of patients with anti-HTLV-Ⅰantibody was higher in patients with adenocarcinoma and squamous cell carcinoma than in those with small cell carcinoma. These findings suggested that HTLV-Ⅰinfection was closely involved in some patients with non-small cell lung cancer having intersitital pulmonary shadows.
polymerase chain reaction