[The diagnostic challenge of primary immunodeficiencies in adults]

Primary immunodeficiencies (PID) constitute a heterogeneous group of genetic disorders caused by defects in the development and/or function of the immune system resulting in an increased susceptibility to recurrent infections. In addition to a predisposition to infections, PID patients present an increased vulnerability to autoimmunity, lymphoproliferation, allergies and malignancies. Studies performed in the past decade revealed that the prevalence of PID in adults was largely underestimated. These have also demonstrated that the disease burden of PID is not less than in children. PID is more common than generally thought.