Diagnostic biologique des déficits immunitaires primitifs

Early diagnosis of primary immunodeficiencies (PID) is critical to improve patients care and to prevent complications. Clinical and biological signs of PID include infections, but also cancers and autoimmune diseases. First-line biological tests - such as blood count, immunoglobulins quantitation and post-vaccines serologies - could be helpful to make the diagnosis. More specialized tests, such as lymphocytes phenotyping and IgG subclasses quantitation, should be done as second-line tests. All these blood exams have to be rigorously interpreted, notably regarding patient's age and infectious agents.