Everything depends on the type of amyloidosis
Type de l'Amylose
Hereditary TTR Amyloidosis
For more than a decade, the treatment for hereditary TTR amyloidosis has been liver transplantation which stops the liver from producing the mutated transthyretin, thereby stabilising the disease’s progression, particularly the neurological effects. In some cases, specialist heart and liver teams will consider doing a double heart-liver transplant.
Liver transplantation used to be the only therapeutic treatment for hereditary amyloidosis. It works by preventing the production of abnormal transthyretin. Now, new medications are in development and becoming more accessible. These medications aim to inhibit the development of amyloid deposits by making the transthyretin tetramers more stable. One of these treatments, Vyndaquel (Tafamidis), received market authorisation from the European Medicines Agency (EMA) in November 2011. It is currently only available in hospital pharmacies and must be prescribed by a neurologist affiliated with a specialist centre. It is aimed at patients who are able to walk without aid and have a known amyloid neuropathy.
Other approaches to treatment, such as gene therapy, are being tested and developed at the moment, notably at Henri Mondor Hospital.
-
ISIS-TTRrx is used to treat hereditary amyloidosis which causes neurological damage. This compound inhibits the production of transthyretin.
-
Tafamidis is used to treat hereditary and senile amyloidosis which damages the heart. This compound stabilises the transthyretin tetramers.
AL Amyloidosis
Treating AL amyloidosis often involves chemotherapy in order to reduce or indeed suppress the plasma cells which produce the immunoglobulins responsible for amyloid deposition. The effectiveness of this treatment is tracked by measuring the immunoglobulin light chains and the normalisation of cardiac biomarkers (BNP, NTproBNP and troponin).
Senile Amyloidosis
Diagnosing senile amyloidosis is often a process of elimination for patients that have heart failure and cardiac hypertrophy. Senile amyloidosis can only be conclusively diagnosed if the myocardial biopsy detects transthyretin amyloid deposits. However, performing a myocardial biopsy on older patients presents an ethical dilemma due to the potential complications (myocardial perforation, lesions in the tricuspid valve). Histological proof of amyloid deposits in senile systemic amyloidosis can be obtained through biopsies of non-cardiac tissue (salivary glands, carpal tunnels, rectum, abdominal fat, etc.) and subcutaneous fat. However, non-cardiac biopsies are less effective at detecting senile systemic amyloidosis than other types of amyloidosis, so a negative result does not eliminate the possibility of senile systemic amyloidosis. Forms of senile amyloidosis can also be localised in the previously mentioned tissues without affecting the heart. However, this does not mean that the heart will not be affected some years later. Patients that have negative biopsies for transthyretin amyloidosis at the time of their carpal tunnel surgery, can still develop a cardiopathy years later. In fact, it is often the case that patients with a history of carpal tunnel treatment are found to have senile systemic amyloidosis 4 or 5 years later. Below is the diagnostic approach for a patient suspected of having cardiac amyloidosis.
This is the diagnostic strategy for suspected cardiac amyloidosis. The MRI can be carried out if the patient has a pacemaker, but an arrhythmia specialist will have to either switch it off or regulate it and then check it after the examination. Implanting patients with pacemakers which are compatible with MRIs makes it easier to evaluate a cardiopathy in this way.
