The problems of clinical trials and registries in rare diseases

SummaryClinical trials to evaluate patients affected by rare diseases are often hampered by the difficulty of recruiting a critical sample size. Registries for rare conditions are thus extremely powerful tools for overcoming recruitment problems. Here we present and discuss the international experience with alpha1-antitrypsin deficiency achieved by the Alpha One International Registry, and national experience obtained with a large series of patients with pulmonary alveolar proteinosis