 Specific Aim 1: To determine the clinical effectiveness of infliximab on chronic beryllium disease. The efficacy of infliximab will be measured by improvement in arterial gas exchange, or arterial alveolar oxygen gradient A-ad02 at end exercise in subjects with CBD who remain symptomatic and with pulmonary impairment despite current treatment with prednisone andor methotrexate. Secondary outcome measures will include change in airflow, lung volume, diffusing capacity DLCO, profusion of small opacities on chest x-ray, dyspnea score, and quality of life questionnaires. 