Adhesive capsulitis: Human fibroblast response to shoulder joint aspirate from patients with stage II disease

Abnormal fibroblast proliferation has been implicated in the pathogenesis of adhesive capsulitis. The aim of the study was to examine the effect of fluid aspirated from the glenohumeral joint of patients with adhesive capsulitis on human fibroblast cells. Shoulder aspirate from 15 patients with stage II adhesive capsulitis was obtained and diluted to concentrations of 10%, 25%, and 50%. Fifteen patients undergoing shoulder arthroscopy for instability comprised the normal control group. Human fibroblast cells were cultured from human volunteers. Cellular proliferation was determined by use of the Promega CellTiter 96 nonradioactive cell proliferation assay. Fibroblast proliferation was significantly increased in patients with adhesive capsulitis. The rate of increased fibroblast proliferation showed a dose-dependent relationship to aspirate concentration. There was a moderate increase in fibroblast apoptosis at higher aspirate concentrations (25% and 50%) as detected by the ability of apoptotic cells to bind annexin V and exclude propidium iodide. These findings demonstrate that fluid from shoulders with adhesive capsulitis contains growth factors that influence fibroblast activity.