shop helvetica, drugs sans-serif; font-size: 1em; background-color: #92d2dd; border: medium solid #333333; text-align: center;">Pulmonary complications are the leading cause of danger to patients with ataxia telangiectasia, pills ahead of cancer.
The term "pneumonia" refers to lung diseases affecting the deep lung.
The bronchi may also be sick from immune deficiency and recurrent bronchitis, with the development of bronchiectasis (permanent bronchi expansion).
We are talking about:
- Pneumonia when the origin of the disease is suspected infectious (bacteria, fungi ...)
- Interstitial lung disease or infiltrative when an infectious cause has been eliminated by the microbiological investigations and lung disease is caused by inflammation. These are the alveoli and the supporting tissue of them that are reworked.
- Bronchiectasis when the bronchi have a chronically increased size.
Lungs and immunity
We saw in chapter "Immunity and AT" that people with AT have a combined immunodeficiency, variable according to individuals, which affects both:
- Cellular immunity: B and T cells
- Humoral immunity: immunoglobulins IgA, IgE and IgG (mainly IgG2, IgG4).
Even the mucous membranes (the first barriers) are affected in ataxia telangiectasia (accelerated aging, IgA deficiency). Those of the respiratory system are therefore entry points for frequent and dangerous infections. They are favored by:
The deficit in T cells (the main actors of the specific -with memory- immune response ), which promotes:
- Viral infections: herpes virus group in particular (Cytomegalovirus: CMV)
- Fungal infections: Cryptococcus (yeast present in the dust), Aspergillus (fungus also present in the dust on construction sites for example)
- Infections with intracellular bacteria: mycobacteria (eg tuberculosis), salmonella and legionella.
The deficit in B cells and immunoglobulins, which promotes:
- Bacterial infections: pneumococcal, Haemophilus influenzae (responsible for various ENT infections and also pneumonia).
- Viral infections (see above).
These deficits may partly be made up by IV of immunoglobulin, but they do not cover the full spectrum of viruses and bacteria. To do this, and according to the deficit, the doctor may prescribe regular and permament medication to a particular antibiotic.
These infections pose a risk of lightning extension and respiratory distress syndrome, irreversible if not caught in time. Even if remission, sequelae may remain with the development of bronchiectasis.
It is the result of repeated lung infections. It is the chronic inflammation and airway obstruction by secretions that damage the bronchial wall.
Preventive treatment is based on immunoglobulin and antibiotics for infections. If bronchiectasis is established, treatment is based on chest physiotherapy (to help drainage of congested airways), in addition to preventive treatment that must be pursued.
This treatment is essential to slow the worsening of the lesions. Indeed, bronchiectasis, once installed, creates a vicious circle:
- Mucosa with ciliated cells lining the airways and allowing the natural drainage of secretions is not functional any more
- The sputum (mucus discharge) is less effective
- The mucus that has imprisoned the seeds is less well drained
- Germs stay put proliferate, thus promoting new infections
The clinical implications are:
- chronic coughing due to stasis (stagnation) of mucus
- secondary bronchial infections more frequent
- shortness of breath: the air is more difficult to travel due to bronchial obstruction and anatomical alterations
Patients with AT may also develop an interstitial pneumonia (see definition at the beginning). It would be the consequence of abnormal lung repair facing the various assaults by deregulation of the immune system or lack of healing after lung aggression (infections, chemical oxidants ...).
The alveoli and the supporting tissue of these cells that are damaged. The final stage is fibrosis with consequent decrease in breathing capacity and a failure to transfer oxygen from the lungs into the blood. This complication is relatively rare (about 5% of patients) but serious, therefore it requires regular pneumologic monitoring to detect and treat it early.
In the bleak picture of ataxia telangiectasia, pulmonary infections are the leading cause of mortality.
But paradoxically, they are also one of the few points on which the family circle can be influential(cf "pneumologist"). In two words: vigilance and prevention.
Moreover, if there are still many unknowns about how these infections destroy the lungs, investigation techniques are in constant progress and treatment are increasingly powerful.