Selective IgA Deficiency in Children

What Is IgA Deficiency?

IgA is an antibody blood protein, a part of the immune system. The body makes IgA and other types of antibodies to fight off sickness. IgA deficiency means low levels or no IgA in the blood in the presence of normal levels of IgG and IgM in blood in children older than four years of age, for whom other reasons for hypogammaglobulinemia are excluded.

IgA is present in mucous membranes alo, mainly in the respiratory and digestive tracts. IgA can also be found in saliva, tears, and breast milk. Researchers linked IgA deficiency with autoimmune health problems which are health problems that cause the body’s immune system to attack their own body by mistake.

What Are the Causes of IgA Deficiency?

IgA deficiency is a health condition that is passed down in families in about one in five cases, making it a genetically inherited condition. However, rarely, it can be caused due to several medicines.

What Are the Symptoms of Selective IgA Deficiency?

Children with selective IgA deficiency may remain asymptomatic, and sometimes it is diagnosed incidentally during regular blood tests. In fact, 85 to 90 % of IgA-deficient people are asymptomatic. However, many children experience symptoms that can vary widely in each child. Some common symptoms include the following:

• Recurrent Sinopulmonary Infections - The respiratory system is most commonly affected by infection in individuals with IgA deficiency. Bacteria such as Haemophilus influenza and Streptococcus pneumonia mostly cause these infections. Some affected individuals may develop end-organ damage, including bronchiectasis due to recurring or chronic infections.

• Gastrointestinal Infections or Disorders - IgA deficiency can cause the development of disorders and infections of the gastrointestinal tract. Some associated gastrointestinal disease includes giardiasis, malabsorption, lactose intolerance, celiac disease, nodular lymphoid hyperplasia, malign proliferation, and ulcerative colitis. In IgA deficiency, the protective barrier of the gastrointestinal tract is impaired. Hence, protozoa can adhere to the inner layer, proliferate, and can lead to infection. Another way of pathogenesis is malabsorption, which may occur secondary to structural damage to the tissues of the intestine. Even in the absence of infection, several molecules may penetrate the subepidermal and submucosal tissue due to impaired mucosal clearance. This process may stimulate antibody production against several antigens and cause intolerance to certain food and cause diseases such as celiac disease.

• Allergic Disorders - Allergic disorders are common in individuals with IgA deficiency. A history of allergy was more common in younger individuals, with a median age of 10.5 years. The most common allergies are respiratory allergies and atopic dermatitis in IgA-deficient children. However, other allergic manifestations, including allergic rhinitis, conjunctivitis, drug allergy, food allergy, and urticaria, can also occur with selective IgA deficiency.

• Autoimmune Diseases - They are the most important clinical presentations of IgA deficiency. Autoantibodies can be detected in individuals with IgA deficiency even if an overt clinical condition is not present. However, autoimmunity is more prevalent in adults, with a median age of 29 years, and not in children. The most common autoimmune disorder associated with IgA deficiency is idiopathic thrombocytopenic purpura followed by juvenile rheumatoid arthritis, thyroiditis, hemolytic anemia, systemic lupus erythematosus, and the existence of various autoantibodies. However, in younger people, autoimmune disorders, such as thyroid disease, arthropathy, celiac disease, systemic lupus erythematosus, and anemia can occur.

• Anaphylactic Reaction - IgA-deficient individuals may develop anti-IgA antibodies that can cause anaphylactic reactions with transfusion of any blood derivative, such as red blood cells or platelets that contain trace amounts of IgA.

• Malignancy - The link between IgA deficiency and malignancies is reported in sporadic cases, especially at older ages. These malignancies are usually of gastrointestinal and lymphoid origins.

How Is Selective IgA Deficiency Diagnosed?

The diagnosis of selective IgA deficiency involves medical evaluations and tests. These may include:

Medical History and Physical Examination - The doctor will review the child's medical history and perform a thorough physical examination to evaluate symptoms and any signs of immunodeficiency, such as allergies, recurrent respiratory and gastrointestinal infections, and autoimmune disorders.

Immunologic Evaluation for IgA Deficiency - The doctor may suggest tests if there is suspicion of IgA deficiency based on symptoms, anaphylaxis following a blood product transfusion, family history, or celiac disease. The evaluation of IgA deficiency includes the following tests:

• Complete blood count test.

• Differential and quantitative serum Ig levels.

• Specific antibody response to polysaccharide antigens and proteins.

• Serum IgG subclasses.

• Lymphocyte subsets.

In addition, the doctor may also advise appropriate laboratory tests for associated conditions, such as recurrent infections, allergies, or celiac disease.

How Is Selective IgA Deficiency in Children Managed?

IgA-deficient children who are coincidentally diagnosed and who do not have any symptoms associated with IgA deficiency do not need any treatment. However, awareness and education are very important to prevent a possible anaphylactic reaction secondary to blood transfusion. Individuals with selective IgA deficiency are advised to wear a medical alert bracelet. Additionally, when a blood transfusion is necessary, the doctor usually screens the affected person for anti-IgA antibodies. If IgA antibodies are present, the blood product is prepared from an individual with IgA deficiency, or saline-washed red blood cells are selected. Moreover, all blood products are given with caution, and the staff is prepared to treat a possible anaphylactic reaction.

In children with IgA deficiency, the main focus of management is the treatment of associated diseases. If the affected individual experiences recurrent infections, the doctor may prescribe daily prophylactic antibiotics continuously or seasonally on an intermittent basis. If the affected person has associated IgG subclass deficiency or specific antibody deficiency, immunoglobulin treatment may be given via an intravenous or subcutaneous route with minimal IgA. In the case of an associated allergic disorder or autoimmune condition, a standard treatment approach is considered.

While there is no cure for selective IgA deficiency in children, appropriate management strategies help minimize the impact of the condition on their health. Preventive measures, including vaccinations according to the recommended immunization schedule, infection control strategies such as teaching affected children good hygiene practices and avoiding close contact with sick individuals, and prompt and appropriate treatment of infections, can all contribute to minimizing complications. Regular follow-up and monitoring of children with selective IgA deficiency allow for the overall assessment of their health, evaluation of immune function, and modification of management strategies as needed.

Conclusion

Selective IgA deficiency requires proper management to minimize its impact on a child's health. By implementing effective preventive measures, promptly treating infections, and, if necessary, providing therapies like immunoglobulin replacement therapy, children with IgA deficiency can lead healthy lives with reduced risk of complications.