From Immunology and Allergy Clinics:
Common variable immunodeficiency (CVID) refers to a grouping of antibody deficiencies that lack a more specific genetic or phenotypic classification.
CVID is the immunodeficiency with the greatest number of constituents, likely because of the numerous ways in which antibody production can be impaired and the frequency in which antibody production becomes impaired.
CVID comprises a heterogeneous group of rare diseases. Consequently, CVID presents a significant challenge for researchers and clinicians.
Common Variable Immunodeficiency - Immunology and Allergy Clinics http://buff.ly/1IR30l3