BERYSARC: a multicentric control case study comparing chronic beryllium disease to pulmonary sarcoidosis

<bold>Introduction:</bold> Chronic beryllium disease (CBD) is a granulomatous disease induced by beryllium exposure. Given CBD and pulmonary sarcoidosis resemblance, misdiagnosis is possible. Also, the prognosis of CBD remains poorly understood. We hypothesized that CBD may exhibit specific clinic-radiological features distinct from sarcoidosis, with a different prognosis. <bold>Methods:</bold> We carried out a French retrospective multicenter study, including 21 patients with CBD, who were compared to 61 matched sarcoidosis patients with parenchymal lung disease. <bold>Results:</bold> CBD patients were mainly Caucasian men (90%) with a mean age of 46 years (±12). CBD resulted always from occupational exposure, predominantly among foundry workers (57%). Clinical findings showed more pulmonary crackles (50% vs 11%) and nail clubbing (16% vs 0%) in CBD than sarcoidosis (p<0.05). The only extrapulmonary organ involved in CBD was the liver (43%), while sarcoidosis affected various organs. Compared to sarcoidosis, FEV1/FVC ratio was significantly higher (0.84 vs 0.72) and DLCO was lower (45% vs 65% pred, p<0.05). Bronchoalveolar lavage in CBD showed a higher proportion of lymphocytes (49% vs 20%, p=0.005). On HRCT, lymph node distribution was similar. Ground glass extent was higher in CBD than sarcoidosis (26% vs 6%). The prognosis was worse in CBD, with the more frequent occurence of pulmonary hypertension, and higher mortality (43% vs 15%). Survival without transplantation was 75% at 10 years for CBD compared to 92% for sarcoidosis (p=0.005). <bold>Conclusion:</bold> CBD presents with distinct clinical and radiological features compared to pulmonary sarcoidosis and carries a worse prognosis with reduced survival.