**Author Listing - Lead/ Submitting Author (we will be communicating with this individual): Name, Institution, City and State where the work was done. Co-authors will be added in a separate section.**
Pitcha Chompoopong, MD, Department of Neurology, Mayo Clinic, Rochester, MN

**Main Body of the Abstract**
Objective: To evaluate clinical presentations and treatment outcomes of neuropathy in AL amyloidosis.
Background: Systemic treatment of AL amyloidosis has advanced in recent years, but neuropathy outcomes have not been studied.
Methods: We reviewed medical records of all AL amyloidosis patients newly diagnosed at Mayo Clinic from 2000-2015. Peripheral neuropathy was assessed based on physical examination, electrodiagnostic, autonomic, and thermoregulatory sweat studies.
Results: Among 1,583 patients with AL amyloidosis, 170(10.7%) had objective evidence of neuropathy at diagnosis. About half (n=84, 49%) presented with length-dependent peripheral neuropathy. One quarter (n=44, 26%) had autonomic neuropathy without somatic symptoms. Other clinical presentations included polyradiculoneuropathy(n=32), small-fiber neuropathy(n=9), and multiple mononeuropathies(n=1). Concomitant myopathy was observed in 32(19%) patients. Median duration of neuropathic symptoms before diagnosis was 12 months. The monoclonal light chain was lambda in 135(79%). Neuropathy was the sole organ involved in 13(8%) patients. Seventy-seven patients had repeat evaluation of neuropathy at median follow-up time of 2.6 years from diagnosis; 46(60%) progressed. Stabilization of neuropathy impairment score (NIS) and electrodiagnostic findings was observed in 19(24%) patients who received autologous stem cell therapy (ASCT, n=11), melphalan-dexamethasone (n=5), bortezomib-based regimen (n=2), and dexamethasone (n=1). Twelve(16%) patients (ASCT, n=8; melphalan-dexamethasone, n=4) had improvement in neuropathic pain, NIS, electrodiagnostic, or autonomic study findings. Median survival was 33 months. Overall survival was not different from AL amyloidosis patients without neuropathy.
Conclusions: Neuropathy in AL amyloidosis frequently presents with length-dependent polyneuropathy or autonomic neuropathy with relentless progression. With advances in therapeutic options, stabilization and even improvement in neuropathy can occur.



**Author Listing - Lead/ Submitting Author (we will be communicating with this individual): Name, Institution, City and State where the work was done. Co-authors will be added in a separate section.**
Pitcha Chompoopong, MD, Department of Neurology, Mayo Clinic, Rochester, MN

**Main Body of the Abstract**
**Objective:** To evaluate clinical presentations and treatment outcomes of neuropathy in AL amyloidosis.
**Background:** Systemic treatment of AL amyloidosis has advanced in recent years, but neuropathy outcomes have not been studied.
**Methods:** We reviewed medical records of all AL amyloidosis patients newly diagnosed at Mayo Clinic from 2000-2015. Peripheral neuropathy was assessed based on physical examination, electrodiagnostic, autonomic, and thermoregulatory sweat studies.
**Results:** Among 1,583 patients with AL amyloidosis, 170(10.7%) had objective evidence of neuropathy at diagnosis. About half (n=84, 49%) presented with length-dependent peripheral neuropathy. One quarter (n=44, 26%) had autonomic neuropathy without somatic symptoms. Other clinical presentations included polyradiculoneuropathy(n=32), small-fiber neuropathy(n=9), and multiple mononeuropathies(n=1). Concomitant myopathy was observed in 32(19%) patients. Median duration of neuropathic symptoms before diagnosis was 12 months. The monoclonal light chain was lambda in 135(79%). Neuropathy was the sole organ involved in 13(8%) patients. Seventy-seven patients had repeat evaluation of neuropathy at median follow-up time of 2.6 years from diagnosis; 46(60%) progressed. Stabilization of neuropathy impairment score (NIS) and electrodiagnostic findings was observed in 19(24%) patients who received autologous stem cell therapy (ASCT, n=11), melphalan-dexamethasone (n=5), bortezomib-based regimen (n=2), and dexamethasone (n=1). Twelve(16%) patients (ASCT, n=8; melphalan-dexamethasone, n=4) had improvement in neuropathic pain, NIS, electrodiagnostic, or autonomic study findings. Median survival was 33 months. Overall survival was not different from AL amyloidosis patients without neuropathy.
**Conclusions:** Neuropathy in AL amyloidosis frequently presents with length-dependent polyneuropathy or autonomic neuropathy with relentless progression. With advances in therapeutic options, stabilization and even improvement in neuropathy can occur.



Peripheral Neuropathy in AL Amyloidosis: Clinical Presentations and Outcomes of Current Therapies OA17 (#264)

We invite you to attend the XIX International Symposium on Amyloidosis to be held in Rochester, MN.

This symposium is organized as a hybrid meeting (with the focus on in-person) held from Sunday, May 26 through Thursday, May 30, 2024.

Together with the ISA Board and members of Mayo Clinic, a very attractive scientific hybrid program is being planned. The program will cover a variety of types of systemic amyloidosis: ATTR (hereditary and wild-type), AL (light-chain), AA and less frequent forms. There will be key lectures, specific symposia including those company sponsored, oral presentations and poster sessions of accepted abstracts.

COURSE DESCRIPTION
This program will provide a comprehensive review of state-of-the-art education in systemic amyloidosis: basic science, pathophysiology, diagnosis, current and emerging treatments. Scientific presentations will include competitive oral and poster abstracts. The rapid evolution of scientific discovery and expanding treatment options has created tremendous interest in the field and this meeting will fill and important gap in educating scientists and clinicians.