X-linked agammaglobulinemia (XLA) is a rare immune disorder characterized by a complete deficiency of B lymphocytes. In the absence of normal mature B cells, affected patients have impaired immunity and are susceptible to infections and illnesses, particularly in the first two years of life, which can sometimes be fatal. Some of the common infections are otitis media, conjunctivitis, sinopulmonary infections, diarrhea, and skin infections. Viral infections are rare, although enetroviral infections may be seen. The disease almost exclusively affects males. Worldwide, less than 1 in 200,000 neonates are affected with this condition.
A diagnosis of XLA is suspected in male infants with recurrent bacterial infections, reduction in all classes of serum immunoglobulins, and a total absence of B lymphocytes. Confirmation of the diagnosis requires mutation analysis of the BTK gene. Treatment involves regular injections or infusions of gamma-globulins. Simultaneously, aggressive use of antibiotics may be required to combat chronic sinusitis and pulmonary disease.