Rev. 2008; originally published 2000

Children and adults with A-T are at increased risk for respiratory problems. Symptoms of lung problems may include frequent coughing, noisy breathing, nasal congestion, fast breathing, shortness of breath during rest or with activities or poor weight gain.

CAUSES OF LUNG DISEASE AND RESPIRATORY SYMPTOMS IN A-T CAN INCLUDE:

Infections and Immunodeficiency: Individuals with an impaired immune system may have more frequent and/or more severe sinus and lung infections than the average person. Sinus and lung infections can occur in the same individual and both can cause coughing. Symptoms of chronic sinusitis can include discolored nasal drainage, postnasal drip, cough and nasal congestion. Bronchitis and pneumonias are lung infections that involve the bronchial airways and lungs. Recurrent bronchitis and pneumonia can cause permanent damage to the airways resulting in a condition called bronchiectasis. People with bronchiectasis can develop chronic bacterial infections of the airways and may have an accelerated lost of lung function.

Impaired Respiratory Muscle Coordination: A-T causes impaired respiratory muscle coordination leading to a weak cough and shallow breathing. This can make it difficult to take a deep breath and clear airway secretions, particularly during respiratory illnesses such as the flu or pneumonia. Difficulty clearing airway secretions can occur at any age but is most common after ten years of age.

Swallowing Problems and Aspiration Pneumonia: Aspiration happens when food, liquid or saliva is inhaled into the airways instead of down the esophagus. Aspiration can cause lung injury and recurrent pneumonias. It is common for individuals with A-T to develop swallowing problems with aspiration, putting them at risk for aspiration pneumonia.  Aspiration may be chronic or intermittent and may be worse during respiratory tract infections and in individuals with who have gastro-esophageal reflux (acid reflux). Aspiration causes most people to cough, however people with A-T often do not cough when they aspirate, making it clinically difficult to diagnose this condition (see Chapter 7).

Interstitial Lung Disease: A subset of individuals with A-T will develop interstitial lung disease (ILD). Symptoms include shortness of breath and dry cough, not associated with a lung or sinus infection. Over time the lungs of people with ILD can develop scarring making oxygen delivery to the lungs more difficult. The causes of ILD are unknown but may be related to immune dysfunction. One study has shown that oral steroids may be helpful in people with A-T and ILD (1).

Other Respiratory Conditions: Having A-T does not preclude children and adults from having other respiratory conditions, not related to their A-T. Asthma is common in the general population and symptoms include intermittent or chronic cough and wheezing. Asthma is often treated with inhaled steroids and bronchodilators that help with opening the bronchial airways and clearing mucous from the lungs. Symptoms of asthma are triggered by environmental factors such as cigarette smoke, air pollution, abrupt changes in the weather, increased exertion and respiratory tract infections. The combination of A-T and asthma may result in additional problems during respiratory infections.

TREATMENT AND PREVENTION OF LUNG DISEASE IN A-T

All people with A-T should be evaluated for immunodeficiency.

• Supplemental immunoglobulin therapy should be considered in appropriate candidates.
• All children and adults with A-T should receive influenza and pneumococcal vaccinations (see immunology chapter)
• All family members of people with A-T should receive yearly influenza vaccinations.

Individuals with A-T may be at increased risk for secondary bacterial infections due to viral illnesses. Antibiotics are not necessary for most colds, but should be considered for those individuals with prolonged respiratory symptoms following a viral infection and those with underlying chronic lung disease. Sometimes intravenous (IV) antibiotics are needed in individuals with bacterial infections who do not respond or get better after an oral course of antibiotics.

The use of preventive antibiotics can sometimes be used in people with A-T and chronic lung disease to decrease the frequency of acute bacterial lung infections. Preventive antibiotics may also decrease bacterial colonization and airway inflammation. It is hoped that this will slow the decline in lung function. A down- side to this approach is the risk of developing resistance to a particular antibiotic. A pulmonary specialist should be consulted before initiation of preventive antibiotics.

Individuals with shallow breathing and weak cough may benefit from the use of airway clearance devices (oscillatory devices and high frequency chest wall oscillation), chest physiotherapy (PT), inhaled steroids and bronchodilators. Sometimes these interventions are necessary only during acute illnesses although other people may benefit from these interventions on a daily basis.

People with A-T who have an impaired swallow should institute measures that limit aspiration and maximize nutritional intake to avoid respiratory complications (see Chapter 7).

Poor nutrition may be associated with decreased respiratory muscle strength and difficulty with handling respiratory infections. Optimizing diet and encouraging appropriate exercise may stabilize or improve lung function.

DIAGNOSTIC STUDIES TO IDENTIFY AND CHARACTERIZE LUNG DISEASE

Spirometry as a measurement of pulmonary function testing (PFTs) should be considered on an annual basis in people with A-T. PFTs are non invasive and can be performed in most individuals when minor adjustments are made to the technique, such as stabilizing the head and maintaining a good seal around the mouthpiece. Annual pulmonary function testing should be considered once the child reaches 12 years of age or when the child is able to follow directions. Useful results from these studies depend on patient cooperation. Annual pulmonary function testing can help identify those individuals with poor lung function and those who may have more rapid decline in lung function as they age. Along with spirometry, measurements of mean inspiratory and expiratory pressures (MIP and MEP) should also be made as a marker for respiratory muscle strength.

Lung volume studies using the helium dilution method should be considered in individuals with a low forced vital capacity (FVC) by spirometry. A low FVC may suggest decreased pulmonary reserve and underlying lung disease. The helium dilution method is easily performed in children who are wheel-chair bound. The test also requires minimal cooperation from the participant. Unfortunately the helium dilution setup is not available at many pulmonary function laboratories. It has been replaced by body plethysmography a technique that requires the individual to sit in a body box and perform a breathing maneuver that may be difficult for people with A-T. Individuals with low forced vital capacities should be evaluated by a pulmonary specialist.

Radiological studies may be clinically indicated in individuals with A-T who have chronic respiratory symptoms or respiratory complaints that continue despite treatment of the acute disease process. Chest x-rays are useful for identifying pneumonias however a CT scan of the chest may be more sensitive in identifying small pneumonias, pulmonary effusions, pneumothoraces, bronchiectasis and interstitial lung disease. A low radiation CT scan should be considered when available to avoid excessive radiation exposure however, conventional radiologic techniques are acceptable when they are clinically indicated.

Sinus disease may be underestimated in individuals with A-T and may exacerbate lower respiratory lung conditions. In A-T, symptoms of sinus disease may be subtle. Often symptoms consists of one or more of the following, chronic nighttime cough, postnasal drip, stuffy nose, upper airway congestion or foul breath. A CT scan or MRI of the sinuses may be useful in diagnosing chronic sinusitis in people with chronic upper airway congestion and/or lung symptoms.

A pre-operative evaluation of lung function should be done in anyone greater then 14 years of age and in any child or adult with chronic respiratory symptoms. This will help the anesthesiologist to understand and anticipate the risks of general anesthesia. Sometimes, children and adults with A-T who have underlying lung disease may have difficulty coming off the ventilator after a surgery or procedure requiring general anesthesia. Possible alternatives to general anesthesia and strategies that maximize airway clearance following anesthesia should be considered. Specific risks for each individual based on their health record and clinical symptoms should be discussed in detail with the anesthesiologist and pulmonary specialist when indicated.

REFERENCE LIST

(1)   Schroeder SA, Swift M, Sandoval C, Langston C. Interstitial lung disease in patients with ataxia-telangiectasia. Pediatr Pulmonol 2005; 39(6):537-543.