O Hialuronano no lavado broncoalveolar, um marcador de activação dos fibroblastos, reflecte a intensidade da inflamação intersticial na Suberose**Trabalho entregue a concurso ao Prémio Thomé Villar 1996, da Sociedade Portuguesa de Pneumologia

ABSTRACTHyaluronan (hyaluronic acid) is a glycosamino-glycan present in the interstitial lung matrix, and produced by activated fibroblasts stimulated by several inflammatory mediators. The increase of hyaluronan in bronchoalveolar lavage fluid (BALF) has been described in several experimental and human fibrotic lung diseases and associated with fibroblast activation.AimsTo Investigate the hypothesis that pulmonary fibroblast activation follows lung recruitment of T lymphocytes and mast cells in Suberosis, we measured BALF hyaluronan in 31 symptomatic cork workers with distinct clinicopathologic patterns.Patients and MethodsWe studied 31 patients with a clinical and occupational history, physical examination, chest X-ray, spirometry, body plethismography and carbon monoxide diffusing capacity, resting blood gases and BAL. Patients were classified in two different syndromes according to clinical, functional criteria and BALF analysis: 20 with hypersensitivity pneumonitis and l I with obstructive lung disease (8 with bronchial asthma and 3 with chronic bronchitis). BALF hyaluronan Levels were measured by a radiometric assay, BALF Albumin and IgG by rate nephelometry and differential and mast cell counts performed in BALF cytospins.ResultsBALF hyaluronan levels were significantly higher in patients with hypersensitivity pneumonitis, with a median (and interquartile range) of 67.1 μg/L (33.7-111.5) versus 22.7 μg/L (12.8-40.7) in patients with obstructive lung disease (p<0.01, Mann-Whitney). We found a significant correlation between BALF hyaJuronan, total cell numbers, albumin and IgG levels (p<0.02, Spearman correlation) and also with the total lymphocyte and mast cell counts (p<0.01). Moreover, we also found a significant inverse correlation between BALF hyaluronan, lung diffusion and Vital Capacity (DLCO rs = -0,58, VC rs = -0,61, p<0.002), and also with the ye.ars of exposure (rs = -0.45, p