What are antibody deficiencies?
Immunoglobulins are antibodies that have many functions, including protecting against infections. In some cases, patients have deficiencies in just some of the immunoglobulins (either too low of an amount or less functional). Antibody deficiencies include Selective IgA Deficiency, Common Variable Immunodeficiency, IgG Subclass Deficiency, Specific Antibody Deficiency, Transient Hypogammaglobulinemia of Infancy, Agammaglobulinemia, and other antibody deficiencies.
What are the symptoms of antibody deficiencies?
A major sign that a child or adult has an antibody deficiency may be recurrent infections, especially of the ears, sinuses, bronchi and/or lungs. Some patients also may present with chronic diarrhea or viral or bacterial meningitis. Evaluation by an immunologist may help determine whether an antibody deficiency is the cause.
How are antibody deficiencies diagnosed?
Antibody deficiencies are diagnosed by measurement of total immunoglobulins, IgG subclasses, and antibody titers to specific antigens such as tetanus, diphtheria, and/or Streptococcus pneumoniae prior to and following administration of a vaccine (eg. pneumococcal polysaccharide vaccine), measurement of lymphocyte subsets, and sometimes genetic testing.
What is the treatment for antibody deficiencies?
Treatment includes immunoglobulin replacement, prophylactic antibiotics, aggressive treatment of infections, and monitoring complications (i.e. bronchiectasis).