Current concepts: Common variable immunodeficiency

Abstract

Common variable immunodeficiency (CVID) is the most frequent symptomatic primary immunodeficiency disorder found in clinical medicine. The immune defect occurs in males and females equally and is characterized by reduced serum levels of IgG, deficient IgA and/or IgM levels, and poor to absent specific antibody responses to infection or vaccinations. Although CVID is considered a primary immune defect, most subjects are diagnosed between the ages of 20 and 40 years old. However, due to the heterogeneous clinical appearance, a diagnostic delay of 5 to 8 years after the first cardinal symptom is common in all countries in which this has been investigated. As the genetics of this immune defect have been further clarified, it is clear that the name "CVID" is an umbrella diagnosis, useful clinically for arranging treatment, but it actually includes a very large number of immune defects, many of which are not yet discovered. Due to prevalence, common inflammatory complications, and numbers of medical encounters, the awareness of CVID is critical for pediatricians, internists, and primary care physicians, including pulmonologists, otolaryngologists, hematologists, and physicians in many other specialties. Here, we outline the early history of CVID, the diagnostic criteria and standard workup of subjects, the clinical manifestations, emerging genetic understandings, and current treatment modalities for patients with this immune defect.