[HTLV-I associated interstitial pneumonia--a case report and bronchoalveolar lavage study].

A 70-year-old male was admitted to our hospital because of fever and dyspnea. The patient was seropositive for HTLV-I and ATL cells were seen in the peripheral blood in the percentage of 2-5. The proviral DNA was positive and the diagnosis of smoldering ATL was made. His chest X-ray film showed diffuse reticulo-nodular infiltrates in both lung fields. The lung tissue obtained by transbronchial lung biopsy showed the lymphocytic infiltrations in the alveolar septa and the submucosa of the bronchioles. Bronchoalveolar lavage (BAL) fluid showed an increased proportion of lymphocytes that consisted mainly of CD3+ DR+ cells and the CD4+/CD8+ ratio was 2.1 during exacerbation and 0.8 after steroid therapy. Anti-HTLV-I IgG and IgA antibodies were positive in both serum and BAL fluid by Western blotting method. It is suggested that T-lymphocyte alveolitis may occur in patients who are seropositive for HTLV-I and the immunological mechanism seems to be responsible.