Management of IgG Deficiency

Diagnostic Evaluation

Confirm IgG deficiency with at least two measurements taken at least 1 month apart to exclude transient decreases, as recommended by the American Academy of Allergy, Asthma, and Immunology 1, 2
Measure all immunoglobulin classes (IgG, IgA, IgM) and all four IgG subclasses simultaneously if subclass deficiency is suspected, according to the Journal of Allergy and Clinical Immunology 1, 3
Assess functional antibody production by measuring specific antibody responses to pneumococcal vaccines, as this is more predictive of infection risk than absolute IgG levels 4, 5

Begin with aggressive antibiotic treatment for acute infections using longer courses than in immunocompetent patients, as suggested by the Infectious Diseases Society of America 1, 3
Implement prophylactic antibiotics for patients with recurrent sinopulmonary infections that negatively impact quality of life, as recommended by the American Academy of Allergy, Asthma, and Immunology 1, 3, 4
Consider IVIG therapy when evidence of permanent organ damage, recurrent infections, or impaired specific antibody production is present, according to the Immune Deficiency Foundation 3, 4, 5

Reassess immune function regularly, as some patients with IgG deficiency may progress to more severe phenotypes, such as Common Variable Immunodeficiency (CVID), as recommended by the European Society for Immunodeficiencies 1, 3
Monitor for resolution of infections over time, which may occur even when the immunologic abnormality persists, according to the Journal of Allergy and Clinical Immunology 1, 3
Avoid diagnosing IgG4 deficiency before age 10 years, as normal ranges are poorly defined in younger children, as suggested by the Pediatric Infectious Diseases Society 1, 3
Be aware of secondary causes of IgG deficiency, including antiepileptic drugs, HIV, and post-transplant states, as recommended by the American Academy of Allergy, Asthma, and Immunology 1, 3