80% of patients with ataxia telangiectasia have an immune deficiency.
The immunologist should be, with the neurologist, the referring doctor.
The doctor for prevention
Indeed, while the most visible signs in ataxia telangiectasia are neurological, danger comes mainly from the deficiency of the immune system, causing lung diseases and half of the cancers in patients with AT: leukemias and lymphomas.
Immunological check up
In case of repeated sinus or respiratory infections, immune deficiency may be suspected. The balance of immune protection is made through a blood test. It analyses:
- The rate of immunoglobulins
- The number and type of B and T lymphocytes
- The response to different vaccines
Usually, the results found do not change with time and do not need to be repeated unless there is an increased number of infections.
Treatments
It is not known at present how to manufacture immunoglobulins (or antibodies), especially since they are often very different and specialized in responding to a particular disease. We know however how to extract, purify and inject them without risk of rejection, since they are only molecules. This is not the case for lymphocytes for which a low rate significantly increases the risk of infection.
The arsenal available to the immunologist to treat immune deficiency is therefore limited and can not completely restore the defenses. He may propose:
- Relevant vaccines and those who are not because the immune system would not answer to them. This is done on a case by case basis according to each deficit
- Taking very regularly an antibiotic to target antigens whose aggression would not be supported by the damaged immune system of AT patients, to prevent lung infections for example.
- All substances and tonics to overcome the deficiencies noticed during regular and necessary blood tests, the immunologist being the best positioned to interpret them.
- A reminder of the basic rules for infections' prevention
- Regular inputs of immunoglobulin to restore acceptable levels in the blood. The solution injected intravenously or subcutaneously comes from the purified plasma of thousands of donors, which were, during their lives, in contact with many diseases for which they have developed specific immunoglobulins. This way an acquired immunity is recreated in patients and will protect them partially against diseases with which they have never been in touch and for them potentially dangerous. Unfortunately, it is almost exclusively a contribution of IgG as IgA are generally poorly tolerated. The IgA (mucosal protection) and IgM are not replaced, which partly explains the increased susceptibility to lung infections retained by the treated patients. In addition, the life of these antibodies is limited (30 to 35 days) and the injections must be repeated every 2 to 4 weeks for infusions, weekly subcutaneously.
The CEREDIH
In France, under the leadership of Professor Fisher (Necker Hospital and Scientific Committee of AT Europe) and the Association Iris, the CEREDIH is the French reference center of hereditary immune deficiencies which includes ataxia telangiectasia. This structure has a network of competence centers located throughout the country and works with the rest of Europe including the ESID (European Society of Immunodeficiency). It is a partner for families and AT Europe from the beginning.