Clinical investigation of pulmonary Mycobacterium avium complex infection in human T lymphotrophic virus type I carriers

Background-Little is known about pulmonary Mycobacterium avium complex (MAC ) infection in human T lymphotrophic virus type I (HTLV-I) carriers. A stud y was undertaken to investigate and clarify the characteristics of pulmonar y MAC infection in these subjects. Methods-Twenty nine patients with pulmonary MAC infection without any under lying pulmonary disorder were investigated. The clinical features and radio graphic appearance of HTLV-I carriers and non-carriers were compared and th e bronchoalveolar lavage (BAL) fluid of these 29 patients and eight normal female control subjects was analysed. Results-The prevalence of the HTLV-I carrier state in patients with pulmona ry MAC infection was 34.5% (10/29) compared with 16.7% (529/3169) among all patients admitted to our department between 1994 and 1998 (odds ratio (OR) 2.63, 95% confidence interval (CI) 1.21 to 5.68). The HTLV-I carriers were all women and all had clinical symptoms, but they did not show systemic di ssemination. Peripheral multifocal bronchiectasis with nodular shadowing wa s seen frequently on the chest computed tomographic (CT) scans of HTLV-I ca rriers. The area of the pulmonary lesions was more extensive than in non-ca rriers (p<0.05). White blood cell (WBC) counts and C reactive protein (CRP) levels on admission were significantly lower in HTLV-I carriers than in no n-carriers (WBC: difference (D) = 1565/mu l, 95% CI -68.9 to 3198.4/mu l; C RP: D = 1.8 mg/dl, 95% CI -0.35 to 3.89 mg/dl). The concentrations of neutr ophil elastase (NE) and interleukin (IL)-8 in BAL fluid were significantly higher in HTLV-I carriers than in non-carriers (NE: D = 1342 mu g/l, 95% CI 704 to 1980.3 mu g/l; IL-8: D = 304.5 pg/ml, 95% CI 89.7 to 519.4 pg/ml). Conclusions-Pulmonary MAC infection causes more diffuse and widespread lesi ons in HTLV-I carriers than in noncarriers.