Malina Oana Sava, Diana Deleanu
Common variable immunodeficiency (CVID) is the most prevalent symptomatic primary immunodeficiency and belongs to the class of predominantly antibody deficiencies. For the positive diagnosis of CVID the following criteria must be fulfilled: a) serum levels of Ig G and at least one of the classes IgA and IgM at least 2 standard deviations below the average for age; b) patient age ≥ 4 years at diagnosis and c) any other defined causes of hypogammaglobulimenia (primary or secondary) have been excluded. Recent sets of diagnostic criteria additionally include clinical, serum immunology, immunophenotype, and histological characteristics that support the diagnosis of CVID (i.e. they increase the diagnostic probability).