An immunoglobulin G deficiency, called IgG deficiency, can be treated with antibiotics in mild cases when infection erupts or intravenous replacement therapy in severe cases where antibiotics prove ineffective. Some patients with an IgG deficiency take a broad-spectrum antibiotic each day to prevent the recurrence of infection. Doctors might rotate the type of medication to prevent antibiotic resistance to one particular drug.
IgG represents one of three classes of antibodies found in human blood, with IgG considered the most important to fight infection. When an IgG deficiency occurs, a patient might suffer from repeated upper respiratory infections of the sinuses, throat, ears, or chest. A regimen of antibiotics generally clears the infection, but it returns after the medication is stopped.
Treatment of patients with an IgG deficiency sometimes involves preventative doses of antibiotics each day. First, the infection is cleared up before preventative medication begins. This therapy usually treats patients who frequently miss work or school because of repeated respiratory infections.
If antibiotic treatment fails to ward off illness, immunoglobulin might be administered intravenously. IgG antibodies are infused into the blood during a procedure that commonly takes one to three hours. If the body begins making adequate levels of IgG, the therapy is discontinued, which is common in young children.
The human immune system consists of proteins and cells that fight foreign material that causes infection. When this system malfunctions, repeated infection occurs. A child’s immune system does not produce IgG until he or she is about six months old; the fetus gets antibodies from the mother while in the womb. If the child’s body does not begin producing the substance, it might lead to an IgG deficiency, provoking repeated sickness. He or she commonly outgrows the condition by the age of three.
IgG deficiency is typically discovered through a blood test that measures the level of immunoglobulin. Sometimes the tests show normal when a deficiency exists because there are four subclasses of IgG. If one subclass registers higher than normal, it may skew results. To obtain an accurate measurement, all four subtypes should be evaluated. Researchers do not know what causes the deficiency, but it might be linked to a gene on a chromosome that malfunctions.
If genes that regulate the immune system are at fault, there is no cure for the deficiency. An infant born with this abnormality might need lifelong treatment. If the problem stems from an immature immune system, it might resolve on its own over time, and IgG treatment can be discontinued.