Immunoglobulin A Deficiency
Immunoglobulin A Deficiency: Excerpt from The 5-Minute Pediatric Consult
Mathew Fogg, MD
Immunoglobulin A Deficiency - BASICS
Immunoglobulin A Deficiency - description
Serum IgA <5 mg/dL and a normal serum IgG and IgM, in patients >1 year
Immunoglobulin A Deficiency - epidemiology
Prevalence is ~1 in 500 in the normal population.
Immunoglobulin A Deficiency - risk factors
Immunoglobulin A Deficiency - genetics
Most common autosomal dominant mode of inheritance with variable expressivity, but the following rare associations also occur:
- 18q syndrome
- Partial deletions in the long or short arm, and ring forms of chromosome 18
- Also associated with HLA-A1, HLA-A2, B8, and Dw3
Immunoglobulin A Deficiency - pathophysiology
Increased incidence of the following:
- Atopy
- Sinopulmonary infections
- GI infections (especially Giardia lamblia)
- Crohn disease
- Ulcerative colitis
- Celiac disease
- Autoimmune illnesses:
- Arthritis
- Lupus
- Immune endocrinopathies
- Autoimmune hematologic conditions
- Chronic active hepatitis
Immunoglobulin A Deficiency - etiology
Inherited disorder
Immunoglobulin A Deficiency - DIAGNOSIS
Immunoglobulin A Deficiency - signs & symptoms
Immunoglobulin A Deficiency - history
- Patients with IgA deficiency:
- Can have frequent sinopulmonary infections
- Can have frequent gastrointestinal infections
- Tend to be allergic
- Have an increased incidence of autoimmune diseases
- ~30% of patients with IgA deficiency are completely healthy.
Immunoglobulin A Deficiency - physical exam
- Look for signs of recurrent infection and atopy.
- Allergies are associated with IgA deficiency. Signs include:
- Cobblestoning of the conjunctiva caused by allergic inflammation in the eyes
- Allergic shiners
- Serous otitis media may be the result of recurrent ear infections.
- Increased ear infections can be seen in IgA deficiency.
- Serous otitis media can be secondary to allergies, also associated with IgA deficiency.
- Pain on palpation of the sinuses: Recurrent sinus infections are associated with IgA deficiency.
- An increased frequency of pneumonia is associated with IgA deficiency.
- Swollen joints: An increased frequency of autoimmune diseases is associated with IgA deficiency.
Immunoglobulin A Deficiency - tests
The general goal is to decide whether the patient’s complaints are consistent with IgA deficiency (frequent upper respiratory and gastrointestinal infections, or allergies).
- Measure serum IgA level.
- If the patient is IgA deficient, exclude other conditions associated with IgA deficiency.
- Serum IgA level: Patient is considered deficient if the serum IgA level is <5 mg/dL.
- Total immunoglobulins: If normal, helps rule out X-linked agammaglobulinemia (Bruton), common variable immunodeficiency, and severe combined immunodeficiency
- IgG subclasses: Study helps rule out an associated IgG2 subclass deficiency. Clinical significance of IgG2 subclass deficiency is controversial.
- Lymphocyte mitogens:
- A functional lymphocyte study
- If normal, helps rule out common variable immunodeficiency, severe combined immunodeficiency, ataxia telangiectasia, DiGeorge syndrome, and Nezelof syndrome
- Lymphocyte Candida antigen stimulation: No response to Candida in vivo is consistent with chronic mucocutaneous candidiasis.
Immunoglobulin A Deficiency - differencial diagnosis
- Toxic, environmental, drugs: Penicillamine and anticonvulsants can induce IgA deficiency.
- Genetic/Metabolic:
- X-linked agammaglobulinemia (Bruton)
- Common variable immunodeficiency
- Severe combined immunodeficiency
- Ataxia telangiectasia
- DiGeorge syndrome
- Chronic mucocutaneous candidiasis
- Nezelof syndrome
- Selective IgG2 deficiency
- Miscellaneous: Patients may be completely healthy, and IgA deficiency may be an incidental finding.
- Common causes: May be the result of decreased synthesis or impaired differentiation of IgA B lymphocytes into IgA plasma cells
Factors that may help alert you to make a referral include:
- Suggestion that IgA deficiency may be part of a more complex immune deficiency. An allergist/immunologist can assist with an appropriate immunologic evaluation.
- IgA deficiency associated with autoimmune disease. Evaluation and treatment by a rheumatologist would be indicated.
- Patient likely to need a blood transfusion. IgA-deficient patients show an increased incidence of anaphylaxis to IgA-containing blood products. The allergist can help select appropriate blood products for these patients.
Immunoglobulin A Deficiency - TREATMENT
Immunoglobulin A Deficiency - general measures
There is no specific drug therapy.
- Recurrent infections should be treated aggressively with broad-spectrum antibiotics.
- Antibiotic prophylaxis to prevent recurrent sinopulmonary infections is often indicated.
- Intravenous gamma globulin is not indicated.
Patients with IgA deficiency may develop antibodies against IgA in transfused blood products. These patients are at risk for anaphylactic (or anaphylactoid) transfusion reactions. To avoid these reactions, these patients may receive:
- Packed RBCs (only if these cells have been washed 3 times)
- Plasma products from IgA-deficient donors
- Autologous banked blood
Immunoglobulin A Deficiency - FOLLOW UP
Patients should be observed for:
- Sinopulmonary infections
- GI infections
- Autoimmune diseases
- Inflammatory bowel disease
Note: It is important to manage infectious complications aggressively and to intervene promptly when the associated conditions present.
Immunoglobulin A Deficiency - prognosis
Survival into the 7th decade is common.
Immunoglobulin A Deficiency - complications
Increased incidence of the following:
- Respiratory tract infections
- GI tract infections
- Atopy
Immunoglobulin A Deficiency - bibliography
- Burrows PD, Cooper MD. IgA deficiency. Adv Immunol. 1997;65:245–276.
Middleton E, Reed CE, Ellis EF, et al. Allergy Principles and Practice. 4th ed. Philadelphia, PA: Mosby; 1993.- Rankin EC, Isenberg DA. IgA deficiency and SLE: Prevalence in a clinic population and a review of the literature. Lupus. 1997;6:390–394.
Sites DP, Terr AI, Parslow TG. Basic and Clinical Immunology. 8th ed. Englewood Cliffs, NJ: Prentice Hall; 1994.- Smith CA, Driscoll DA, Emanuel BS, et al. Increased prevalence of immunoglobulin A deficiency in patients with the chromosome 22q11.2 deletion syndrome (DiGeorge syndrome/velocardiofacial syndrome). Clin Diagn Lab Immunol. 1998;5:415–417.
Immunoglobulin A Deficiency - CODES
Immunoglobulin A Deficiency - icd9
279.0 Deficiency of humoral immunity
Immunoglobulin A Deficiency - PATIENT TEACHING-MED
- Recurrence risk for a couple with an affected child depends on the mode of inheritance:
- Most commonly, the mode of inheritance is autosomal dominant and the risk would be 50%.
- However, expressivity is variable, and the patient’s phenotype may not be that of an IgA-deficient person.
- IgA deficiency can be induced by some anticonvulsants and by penicillamine.
- IgA-deficient patients should wear medical alert bracelets. These patients can have anaphylaxis if administered blood products containing IgA. In an emergency situation, this is important information for the caregivers to have.
Immunoglobulin A Deficiency - FAQ
- Q: What is the recurrence risk for a couple with an affected child?
- A: It depends on the mode of inheritance. Most commonly, the mode of inheritance is autosomal dominant and the risk would be 50%. However, the expressivity is variable and the patient’s phenotype may not be that of an IgA-deficient person.
- Q: Does the patient take any medications?
- A: The IgA deficiency can be induced by some anticonvulsants and by penicillamine.
- Q: Should IgA-deficient patients wear medical alert bracelets?
- A: Yes. These patients can have anaphylaxis if they are given blood products containing IgA. In an emergency situation, this is important information for the caretakers to have.
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Book Source Details
- Book Title: The 5-Minute Pediatric Consult
- Author(s): M. William Schwartz MD; et al.
- Year of Publication: 2008
- Copyright Details: The 5-Minute Pediatric Consult, Copyright © 2008 Lippincott Williams & Wilkins.
More About Common Variable Immunodeficiency
More Medical Textbooks Online about Common Variable Immunodeficiency
Review other book chapters online related to Common Variable Immunodeficiency:
Copyright notice for book excerpts: Copyright © 2008 Lippincott Williams & Wilkins. All rights reserved.
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More About This Book:
Title: The 5-Minute Pediatric Consult
Authors: M. William Schwartz MD; et al.
Publisher: Lippincott Williams & Wilkins
Copyright: 2008
ISBN: 0-7817-7577-9
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