Lung problems cause sickness and death in many patients with ataxia-telangiectasia (A-T). However, a lack of information from following A-T patients’ lung disease over time has limited doctors’ knowledge of these critical problems. With the goal of providing expert advice on the diagnosis, evaluation, and management of lung disease in A-T, Dr. Sharon McGrath- Morrow and her colleagues at the A-T Clinical Center recently published a state-of-the-art paper in the journal “Pediatric Pulmonology.”
This paper describes what they have learned from seeing many patients with A-T and observing similarities with more well-studied lung diseases. Dr. McGrath also presented her team’s findings at a recent workshop and recommended various steps for other doctors to follow.
Many factors can predispose people with A-T to lung disease. These include susceptibility to infections, abnormal immune response, recurrent aspiration (food or liquids slipping into the windpipe), and impaired clearance of respiratory tract secretions. Several of these factors also contribute to the progression of other lung diseases such as emphysema and pulmonary fibrosis (the formation of excessive fibrous connective tissue). Clarifying the impact of these factors on lung disease and its progression in A-T may help researchers discover new ways to improve or lengthen patients’ lives.
In her paper, Dr. McGrath described three types of lung disease in A-T patients that require further study: 1) recurrent sinus and lung infections and bronchiectasis (which includes destruction of the lungs’ muscle and elastic tissue), 2) interstitial lung disease (ILD) (that involves damage to the tissue and space around the lungs’ air sacs) and pulmonary fibrosis, and 3) lung disease associated with neuromuscular problems. In A-T, two or more of these problems are often seen in the same patient.
In patients with A-T who have recurrent sinopulmonary problems and bronchiectasis, researchers need to determine how effective aggressive antimicrobial treatment is for acute exacerbations and the role of long-term, preventative antibiotic regimens when proven bacterial colonization may or may not be involved. Dr. McGrath also recommended that researchers explore the use of anti-inflammatory medication to reduce lung inflammation in A-T.
Interstitial Lung Disease
Dr. McGrath also emphasized that more treatment options are needed for A-T patients who have ILD that includes chronic dry cough, rapid breathing, shortness of breath on exertion, hypoxemia (abnormally low oxygen), and crackles, in the absence of viral or bacterial infections. Steroid responsiveness, optimal steroid regimens and the use of immunomodulatory doses of gammaglobulin and hydroxychloroquine need to be assessed. Studies should also be performed that characterize 1) the unique forms of ILD found in A-T and 2) the use of biomarkers such as serum KL-6 and surfactant proteins A and D as indicators of disease progression and risk factors for developing ILD.
Weak Respiratory Muscles
A-T patients with weak or poorly-coordinated muscles that impair their upper airways need to be identified early, as they may be at increased risk for prolonged or difficult recovery from respiratory illnesses. Cough or congestion with meals in these individuals may suggest abnormal swallowing and the tendency for food to go down the windpipe. Dr. McGrath would like to see researchers address: 1) the optimal time to institute regular pulmonary clearance measures such as chest physiotherapy, flutter valve therapy, and cough assist devices, 2) the usefulness of gastric tube placement, and 3) the identification of regimens that may stabilize or enhance muscular strength, such as exercises or devices to increase expiratory muscle strength and strategies to improve swallowing function.
Lastly, Dr. McGrath noted that, for these critically needed studies to happen, multiple centers around the world that treat A-T patients need to work together to improve how lung disease is evaluated and managed. Also, an international registry that includes all individuals with A-T could capture and make available to researchers valuable data on the course of A-T related lung problems. This would help scientists generate new ideas and would serve as a source for patient recruitment into multicenter clinical trials.
Reference: McGrath-Morrow, S.A., Gower, W.A., Rothblum-Oviatt, C., Brody, A.S., Langston, C., Fan, L.L., Lefton-Greif, M.A., Crawford, T.O., Troche, M., Sandlund, J.T., et al. (2010). Evaluation and management of pulmonary disease in ataxiatelangiectasia.