Increased expression of HBZ and Foxp3 mRNA in bronchoalveolar lavage cells taken from human T-lymphotropic virus type 1-associated lung disorder patients.

OBJECTIVE Human T-lymphotropic virus type 1 (HTLV-I) causes adult T-cell leukemia/lymphoma (ATLL), and is associated with chronic inflammatory diseases, including inflammatory pulmonary diseases. HTLV-I bZIP factor (HBZ), which is expressed in all adult T-cell leukemia cells, plays a critical role in the development of lymphoma and systemic inflammation. HTLV-I is harbored by CD4(+) T cells that express forkhead box P3 (Foxp3), and HBZ interacts with Foxp3. This study investigated the chest computed tomography (CT) findings and expression of HBZ and Foxp3 in the bronchoalveolar lavage (BAL) cells from patients with HTLV-I-associated lung disorders. METHODS CT scans obtained from 37 patients (10 men and 27 women, aged 37-77 years) with HTLV-I-associated lung disorders were retrospectively evaluated. The expression levels of HBZ and Foxp3 mRNA in BAL cells and the levels of inflammatory cytokines in the BAL fluid (BALF) from patients were compared with those in control subjects. RESULTS CT scans frequently revealed a diffuse panbronchiolitis (DPB)-like pattern, along with a nonspecific interstitial pneumonia (NSIP) pattern. An analysis of the BALF revealed lymphocytosis and increased expression of HBZ mRNA in patients with HTLV-I-associated lung disorders. The expression of Foxp3 mRNA positively correlated with the percentages of lymphocytes present in the BALF. The inflammatory cytokine and IL-10 levels were significantly increased in the BALF from patients with HTLV-I-associated lung disorders. CONCLUSION The NSIP pattern may be a manifestation of pulmonary involvement in HTLV-I-infected patients, as is the DPB-like pattern. HBZ and Foxp3 likely have a role in the development of lung inflammation.