Agammaglobulinemia is an uncommon type of immune system disorder in which the body does not produce enough immunoglobulin (Ig), an important antibody in fighting off bacteria and viruses. A person with very low levels of Ig is highly susceptible to infections. In almost all cases, agammaglobulinemia is the result of a genetic mutation that is inherited from one or both parents. The disorder is usually seen in infants and children under the age of four who experience chronic diarrhea, frequent skin infections, and several bouts of pneumonia or bronchitis. Patients who are diagnosed with the condition typically receive regular intravenous injections of Ig to keep their immune systems strong.
The gene affected by agammaglobulinemia is called Bruton tyrosine kinase (Btk), named for the physician who first described the condition. A Btk mutation severely affects the immune system's ability to produce Ig, and sometimes halts production altogether. The vast majority of patients diagnosed with agammaglobulinemia are males whose parents possess recessive Btk genes. In rare cases, a person can acquire the condition after suffering a severe infection or experiencing an allergic reaction to immunosuppressive medication.
Infants and young children who have the disorder are very susceptible to viruses and bacteria. Patients are especially prone to flu viruses, salmonella, and respiratory tract infections like pneumonia. Signs that a child may have agammaglobulinemia include persistent skin infections, chronic diarrhea, and severe bronchitis. A child may also suffer from frequent ear and sinus infections.
Parents should seek the guidance of a pediatrician if their child experiences frequent illnesses and infections. A pediatrician can diagnose agammaglobulinemia by examining the child's medical history and taking blood samples to check for low levels of Ig. The doctor may also suggest that parents be screened for Btk abnormalities to confirm a diagnosis. Once agammaglobulinemia has been confirmed, the pediatrician can explain treatment options.
Treatment for agammaglobulinemia usually involves an injection of intravenous Ig, which might come from donor blood or synthetic antibodies. Since Ig production does not normally improve over time, patients are often required to receive injections at regular intervals throughout their lives to avoid chronic health problems. Doctors also treat primary infections with oral and topical antibiotics. If a child's respiratory tract has been severely damaged from frequent infections, he or she may need to undergo surgery to repair damaged tissue. With regular treatments and checkups, most children are able to recover from their symptoms and successfully maintain their health.