LAUSR

Background: The lymphocytic alveolitis in sarcoidosis depends on AL accumulation in lower airways. This phenomenon is probably associated with alterations of AL apoptosis and needs further explanation. Aim: Examination of AL apoptosis rate in sarcoidosis related to the disease presentation – patients were subdivided into Loefgren’s syndrome, LS, chronic stable sarcoidosis, SC, and chronic progressive sarcoidosis, PS. Methods: BAL of 123 patients and 17 controls was examined for: a) AL typing; b) cell cycle analysis (sub-G1 peak for apoptosis); c) TUNEL assay; d) AL staining for death receptors (DRs: TNFR1, DR4, DR5, Fas, PD-1) and e) their ligands (FasL, TRAIL). In 7 PS patients apoptosis was revaluated after 3-6 months of corticosteroid treatment. Results: AL apoptosis rate was lower (p Conclusions: AL apoptosis rate is reduced only in active clinical forms of sarcoidosis. The mechanisms may include low death receptors and their ligands expression on AL. Reduced apoptosis is responsible for AL accumulation in lower airways of sarcoidosis patients.