Allergy Aspergillus

Question

My 16 year old son has CF. He is allergic to the mould aspergillus. For that reason, he has very high IgE values (8200). His lung function is poor, he feels tired all the time, he coughs a lot. He loses weight because he has no appetite. In the past, he was treated with prednisone and that decreased the values of IgE. Now he is again taking prednisone 2x30 mg per day. He also had 7 injections of Omalizumab. But now the value doesn’t want to drop. What could be the cause and are there other medicines?

Answer

Dear parent,
Thanks for this question about an important complication in some patients with CF. On this forum we can only give you some general information. It is obvious that Ecorn is not the appropriate place to discuss the specific treatment of your son; you should discuss his treatment with your doctor.
The complication that you describe, has a difficult name: ‘allergic bronchopulmonary aspergillosis’, in short ABPA. You can best describe it as an allergic reaction to the presence of a mould –Aspergillus- in the airways and in the secretions. Aspergillus is a mould that is really encountered everywhere; but high concentrations are present in damp and dusty places (stables, construction sites). Inhaling this mould when you’re healthy doesn’t cause any problem.
In people with diminished immunity (e.g. patients with cancer under chemotherapy) this mould can cause life threatening lung infection.
In patients with CF, this mould rarely causes infection but we know an allergic reaction ‘ABPA’ as a complication. Due to an allergic reaction to this mould, patients cough, wheeze, have shortness of breath and increased secretions. On the chest X-ray, new abnormalities can show up and lung function drops. It is not always easy to make the distinction between ‘classic’ bacterial infection and allergic reaction to aspergillus.
For this we need blood tests: high IgE and high numbers of allergic cells (eosinophils) in the blood, together with positive allergy tests for Aspergillus in the blood or on the skin point towards ABPA.
The treatment of this complication is not clearcut and there is little evidence for the different treatments used. Cortisone or prednisone is certainly the traditional corner stone in the treatment. This important anti-inflammatory medicine diminishes the allergic reaction. Possibly, the add-on of an antifungal drug (drug that kills moulds) is helpful but there is again little scientific evidence for this. Most frequently itraconazole or voriconazole are used. These medicines are however not always taken up in the blood very efficiently by patients with CF. Another possibility is administering an antifungal medicine via aerosol but again there is little experience with this.
The medicine that you write about is omalizumab, a very specific (‘monoclonal’) antibody to the IgE antibody that rises during some allergic reactions. This antibody then combines (‘binds’) with the allergic antibody and thereby diminishes the allergic reaction. This medicine came on the market for treatment of severe asthma. Several doctors reported beneficial effects of this new medicine for treatment of ABPA in subjects with CF. Currently, an international study evaluates this in an objective way.
It is important to know that when omalizumab is injected, IgE is ‘bound’ and disappears very slowly out of the body. That is why the values of IgE in the blood remain high. To evaluate the effect of omalizumab, you cannot use the IgE level in the blood but you have to look at the symptoms of cough, shortness of breath, and the effect on lung function and allergic cells in the body.
To summarize: ABPA is a well-known complication in CF. The treatment is difficult and long-term. There is little scientific evidence to state which treatment is best. The specific study to evaluate the usefulness of omalizumab is underway.
We hope that this is an adequate answer to your question.

Sincerely yours,


M. Proesmans, K. De Boeck, J. Dankert-Roelse

23.03.2009