PREDICTIVE VALUE OF RESPONSE TO TREATMENT OF T-LYMPHOCYTE SUBPOPULATIONS IN IDIOPATHIC PULMONARY FIBROSIS

T-cell types are important in maintaining immune homeostasis in the lu ng and their imbalance may be associated with several diseases. We exa mined the relationship between bronchoalveolar lavage (BAL) T-cell sub set profiles and the clinical course of 46 patients with idiopathic pu lmonary fibrosis (IPF). A flow cytometry cell sorter (FACS) was used t o analyse the T-cell subsets. Pulmonary function tests (PFT) were perf ormed at baseline and 6-12 months later. Patients were divided into tw o groups according to their CD4/CD8 ratio: CD4/CD8>1 (group 1, n-21); and CD4/CD8<1 (group 2, n=25). A lower percentage of lymphocytes, a hi gher percentage of CD8/S6F1 cells (cytotoxic T-lymphocytes) and a high er percentage of neutrophils were found in the BAL in group 2 compared to group 1 (11+/-7.5% versus 19+/-13.2%; p=0.024 and 29.8+/-17.6% ver sus 13.3+/-6.9%; p=0.068, respectively for lymphocytes and cytotoxic T -lymphocytes; and 8+/-11% versus 29+/-27%; p=0.003 for neutrophils). I nversely, in the peripheral blood, the distribution of CD8/S6F1 cells was lower in group 1 than in group 2 (8.3+/-6.9% versus 33.4+/-16.5%; p=0.0048). The patients were followed over a period of 1 yr in order t o test whether those findings could determine efficacy of therapy. The baseline transfer factor of the lung for carbon monoxide (TL,Co) capa city in group 1 and group 2 was 59+/-22% and 51+21%, respectively (p=0 .29), but only in group 1 was the TL,CO capacity improved significantl y in response to steroids treatment after 6-12 T-cell subsets months. IPF patients with a higher percentage of lymphocytes, a lower percenta ge of neutrophils, CD4/CD8 >1 and a low percentage of CD8/S6F1 may hav e a more benign course of disease. These parameters may identify an ea rly stage of reversible disease responsive to therapy. We conclude tha t these measurements may be a useful tool in monitoring response to tr eatment in patients with idiopathic pulmonary fibrosis.