**15. Complications**

The most common secondary complications of XLA are chronic sinusitis, chronic lung disease, malabsorption, and enteroviral infection. The delay in diagnosis of XLA remains a significant problem, as a consequence of recurrent pneumonias, bronchiectasis, pulmona‐ ry hypertension, and finally cor pulmonale may develop. Many patients have been diagnosed after chronic sequel had already been existed. The aggressive use of antibiotics can decrease the incidence of chronic sinusitis and lung disease. Hearing loss is a conse‐ quence of chronic otitis media. Early diagnosis and treatment of bowel infections may decrease the risk of inflammatory bowel disease. Renal AA amyloidosis had been report‐ ed in 38-year-old patient with Bruton's disease [103].

## **16. Mortality**

Chronic lung diseases and infections, especially disseminated viral infections, and menin‐ goencephalitis due to enterovirus are major causes of mortality. Treatment with newly developed and improved immunoglobulin products and antibiotics and improvement of care of immunodeficient patients would reduce the mortality rates and increase the survival of XLA patients. Registered 41 XLA patients were followed up 20 years until 2010. Among 41 patients, 26.8% died during the follow-up period. All of the complications existed before the initiation of treatment was reduced after immunoglobulin replacement therapy, except sinusitis and conjunctivitis. The associations between some immunological and clinical characteristics such as lymphocyte subsets, consanguinity marriage, and mortality were documented [104].

## **17. Prognosis**

In the case of the early diagnosis of XLA and an appropriate therapy before the appearance of sequel, prognosis is well. They are encouraged a full active lifestyle and children can attend to all regular school. Attention should be paid to pulmonary infections and complications in the long-term follow-up of patients. XLA is a chronic disease; patients need immunoglobulin replacement therapy to avoid infections and care of a multidisciplinary team of specialists for the rest of their lives [98, 99].
