The treatment of a patient suffering from hereditary amyloid neuropathy requires specialist care from a pluri-disciplinary team composed of a minimum of a neurologist, a cardiologist, an ophthalmologist and a geneticist.
The treatment includes anti-amyloid treatment if possible, treatment of the manifestations of the disease, medico-social care and genetic advice for the detection and care for carriers of a mutation of the TTR gene.
Anti- amyloid treatments
Their purpose is to prevent the formation of new deposits of amyloidosis by stabilising Transthyretin and blocking its production. The treatments available so far are only able to slow down the progression and even to stop it but not to get rid of the symptoms already present.
- a) Liver transplant
The purpose of a liver transplant is to remove the main organ producing abnormal TTR protein even if the liver is functioning perfectly well otherwise. A liver transplant is a complicated operation that needs to be performed in a specialized centre.
This treatment has been offered to over 2000 patients worldwide. It has been effective in stopping the progression of the disease in a large majority of cases (70%) treated in their early stages. It is not advised for patients who developed the disease late in life or for carriers of a certain type of mutation. It cannot be performed on patients over 70 years old.
In spite of the transplant, the disease sometimes continues to develop in the nervous system and the heart. This deterioration can be explained by an accumulation of non-mutated (wild) TTR after a liver transplant in subjects over 50.
- b) “Anti-amyloid” medication
Tafamidis ® (Vindaqel ®) is the only medication currently authorized by the French authorities. It is a stabilizer of mutated transthyretin which slows down the progression of the disease. It is a tablet which is taken daily. It is well tolerated and must be prescribed by a neurologist who is familiar with the disease. Other medicines are currently being developed and tested for patients who are not candidates fot a liver transplant. They aim at inhibiting the production of both the mutated transthyretin protein and normal TTR protein by blocking its production by the cells of the liver.
- c) Medication repressing the expression of the TTR gene
Medication has been developed to control and reduce the expression of the Transthyretin gene. These molecules are administered by repeated intravenous or subcutaneous injections. They block most of the mutated and wild transthyretin by the cells of the liver. Two important international studies are being carried out currently to test the effectiveness of these medicines on the progression of the neuropathy.
Treatment of the manifestations of the disease
It is very important to correct the manifestations of the disease to ensure everyday comfort and improve the patients’ quality of life.
Nervous (neuropathic) pain is treated by specific painkillers. Recently, local treatments have been developed using a patch to be applied to painful areas. Special precautions need to be taken to protect insensitive legs and feet from burns and wounds.
For vegetative disorders, there exist corrective treatments, mainly in the form of diets and medication.
For motor disorders, physiotherapy is indispensable.
It may be necessary to implant a pacemaker to protect the patient from sudden cardiac arrest.
When it is responsible for impaired vision, vitreous damage may be treated by a surgical ablation of the vitreous body (vitrectomy) which will remove the amyloid deposits and recover the patient’s sight. It is most often combined with ablation of the lens. Glaucoma is treated with eye drops which lower ocular tension. When the latter are ineffective, it is possible to use laser treatment or glaucoma surgery (trabeculectomy) to lower ocular tension. Dryness of the eye is treated with drops which replace tears (lachrymal substitutes).