immunology allergic disorders
Common Variable Immunodeficiency (CVID)
Diagnosis of CVID
Measurement of serum immunoglobulin (Ig) and antibody titers Flow cytometry for T-cell and B-cell subsets Serum protein electrophoresis Diagnosis of common variable immunodeficiency is suggested by recurrent sinopulmonary infections and requires all of the following: Low (at least 2 standard deviations below the mean) levels of IgG Low levels of IgA, IgM, or both Impaired response to immunizations (usually both protein and polysaccharide vaccines) Exclusion of other immunodeficiency disorders Antibody or autoantibody levels should not be measured if patients have been treated with IV immune globulin (IVIG) within the previous 6 months because any detected antibodies may be from the IVIG. B-cell and T-cell quantification by flow cytometry is done to exclude other immunodeficiency disorders and to distinguish CVID from X-linked Agammaglobulinemia , Spirometry, complete blood count, liver tests, and a basic metabolic panel are recommended yearly to check for associated disorders. If lung function changes, CT should be done. Because mutations are usually sporadic, screening relatives is not recommended unless there is a significant family history of CVID. 