Peripheral neuropathy in wild type transthyretin amyloidosis. (P1.438)

Objective: To examine the prevalence of neuropathy in patients diagnosed with wild type TTR amyloidosis (ATTRwt).

Background: Patients with mutations in the transthyretin gene develop amyloidosis, with primarily peripheral neuropathy and cardiomyopathy, caused by extracellular deposition of abnormal protein fibrils. Currently, prevalence of ATTRwt is about 10–20% of patients with heart failure and preserved ejection fraction and is believed to primarily cause cardiomyopathy and not neuropathy. However, the prevalence of polyneuropathy in ATTRwt patients is unknown.

Design/Methods: We retrospectively reviewed the records of 2 groups of patients. Group A consisted in 107 patients with ATTRwt followed by the Cardiology Department at Columbia University Medical Center. Group B consisted in 10 patients referred to the Neurology department with ATTRwt amyloidosis for evaluation of neuropathy. Data collected includes medical history, EMG reports, laboratory and skin biopsy results

Results: Group A revealed 30.8% (n=33) patients with neuropathy symptoms. Specifically, age, gender, BMI, diabetes mellitus, B12 deficiency, and “back” disease did not differ between patients with and without neuropathy symptoms (p>0,05).

Group B had 100%(n=10) of patients diagnosed with neuropathy, either by nerve conductions and EMG or skin biopsy for epidermal nerve fiber density, although 50% of patients had a presentation consistent with spine disease, 40% with sensorimotor polyneuropathy and 10% had a mixed picture. 75% of the patients that presented with neurological symptoms prior to cardiac symptoms were diagnosed with small fiber neuropathy and 20% of the patients in Group B have not presented with cardiac symptoms yet.

Conclusions: Symptoms of peripheral neuropathy are common in patients with ATTRwt. Clinical presentation is sometimes masked by the history of spine disease and should be better evaluated. Some patients have neuropathy symptoms before the onset of cardiac symptoms. Further prospective studies, with objective outcomes of neuropathy are necessary to characterize the presence of neuropathy in this group.

Disclosure: Dr. Wajnsztajn has nothing to disclose. Dr. Kim has nothing to disclose. Dr. Boehme has nothing to disclose. Dr. Maurer has nothing to disclose. Dr. Brannagan has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Alnylam. Dr. Brannagan has received research support from Ionis, Alnylam.