Common Variable Immunodeficiency (CVID)

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Presentation :

Diagnosis is usually delayed until adolescence or adulthood (typically between ages 20 and 40)
- Although a history of recurrent infection throughout childhood may often be elicited
Patients with CVID have recurrent sinopulmonary infections
Associated with autoimmune disorders such as:
- Autoimmune thrombocytopenia, hemolytic anemia, pernicious anemia,
- SLE, RA, alopecia
- Addison disease, thyroiditis,
Also associated with:
- Bronchiectasis
- Gastric carcinoma or lymphoma occurs in 10% of patients
- Increased risk of other malignancy

Diagnosis of common variable immunodeficiency is suggested by recurrent sinopulmonary infections and requires all of the following:
- Measurement of serum immunoglobulin (Ig)
  - Must have low (at least 2 standard deviations below the mean) levels of IgG
  - Must have low levels of IgA, IgM, or both
- Measurement of antibody titers
  - Must have Impaired response to immunizations (usually both protein and polysaccharide vaccines)
- Flow cytometry for T-cell and B-cell subsets
  - To exclude other etiologies of immunodeficiency (X-linked agammaglobulinemia, multiple myeloma, and CLL)
  - Findings may include low numbers of memory B cells or CD21+ cells
- Serum protein electrophoresis
  - To exclude monoclonal gammopathies (like MM), which may be associated with reduced levels of other immunoglobulin isotypes
Spirometry, CBC, 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.

Prophylactic pooled IVIG replacement therapy is performed through IV or SubQ. Prophylactic replacement is associated with lower rates of infections and hospitalizations
- Prophylactic antibiotics are not typically indicated because they can predispose patients to infection with more resistant organisms. Though some recent trials show benefit for some populations:
  - Double-blind, placebo-controlled, randomized trial on low-dose azithromycin prophylaxis in patients with primary antibody deficiencies
Live vaccines should be avoided
- Immunization is only partially effective because of impaired vaccination response otherwise