Practice of Hereditary ATTR Amyloidosis in Non-endemic Areas of Japan.

Objective Hereditary ATTR (ATTRv) amyloidosis was once an incurable disease; however, in recent years, disease-modifying therapies, such as tafamidis and patisiran, have become available. We herein report the medical care situation in an ATTRv amyloidosis non-endemic area of Japan. Methods We confirmed the information in the medical records of our department and analyzed the data retrospectively. Patients Patients with ATTRv amyloidosis who were treated in our department between 2010 and 2021 were included. Results A total of 15 ATTRv amyloidosis cases (8 men and 7 women) were treated in our department during the study period; 9 patients had a family history, and the transthyretin V30M (p.V50M) gene mutation was present in 66% of cases. The average age of the onset was 57 years old, with 73% of the initial symptoms being dysesthesia and 13% being autonomic dysfunction. Ten patients were treated with tafamidis and nine with patisiran. Although it took a long time to start treatment among our experienced cases, there were some cases in which treatment could be introduced relatively early. Conclusion ATTRv amyloidosis is treatable and should be included in the differential diagnosis of neuropathy so that it can be diagnosed early and introduced into treatment. In the near future, the presymptomatic diagnosis of ATTRv amyloidosis and genetic counseling will become more important.

IgG4-Related Peripheral Neuropathy with Unilateral Cervical Nerve Root and Brachial Plexus Swelling: A Case Report.

A 64-year-old man presented with left upper limb weakness and dysesthesia for 4 months. Magnetic resonance imaging demonstrated swelling from the 6th-8th left cervical nerve roots to the left brachial plexus. The serum IgG4 level was elevated (762.7 mg/dL). 18F-FDG-PET showed high uptake in the mediastinal lymph nodes, and biopsy revealed infiltration of IgG4-positive plasma cells. We diagnosed IgG4-related neuropathy, and steroid therapy administration improved the symptoms. IgG4-related disease should be considered in the differential diagnosis of peripheral nerve swellings. If biopsy of the disordered nerves is difficult, lymph nodes or other organs should be considered.

Elderly patients with suspected Charcot-Marie-Tooth disease should be tested for the TTR gene for effective treatments.

BACKGROUND AND AIMS: Some hereditary transthyretin (ATTRv) amyloidosis patients are misdiagnosed as Charcot-Marie-Tooth disease (CMT) at onset. We assess the findings to identify ATTRv amyloidosis among patients with suspected CMT to screen transthyretin gene variants for treatments. METHODS: We assessed clinical, cerebrospinal fluid, and electrophysiological findings by comparing ATTRv amyloidosis patients with suspected CMT (n = 10) and CMT patients (n = 489). RESULTS: The median (interquartile range) age at onset of neurological symptoms was 69 (64.2-70) years in the ATTRv amyloidosis vs 12 (5-37.2) years in CMT group (Mann-Whitney U, p < 0.01). The proportion of patients with initial sensory symptoms was 70% in the ATTRv amyloidosis group vs 7.1% in CMT group (Fisher's exact, p < 0.01). The proportion of patients with histories of suspected chronic inflammatory demyelinating polyneuropathy (CIDP) were 50% in the ATTRv amyloidosis group vs 8.7% in CMT group (Fisher's exact, p < .01). Other measures and outcomes were not different between the two groups. Five of the six patients with ATTRv amyloidosis received treatment and survived. INTERPRETATION: For effective treatments, the transthyretin gene should be screened in patients with suspected CMT with old age at onset of neurological symptoms, initial sensory symptoms, and histories of suspected CIDP.

Postoperative thyroid storm after radical nephrectomy for renal cell carcinoma with inferior vena cava tumor thrombus.

INTRODUCTION: Thyroid storm is a rare life-threating condition. We report a case of thyroid storm after radical nephrectomy for renal cell carcinoma with inferior vena cava tumor thrombus. CASE PRESENTATION: A 76-year-old man with a left renal tumor and tumor thrombus extending into the inferior vena cava underwent left radical nephrectomy and thrombectomy. After the surgery, his postoperative course rapidly deteriorated, including central nervous system disturbance, fever, tachycardia, congestive heart failure, and hepatic manifestation. Thyroid function test revealed perioperative hyperthyroidism. Corticosteroids and inorganic iodide improved his condition, suggesting that he developed thyroid storm after surgery. He was discharged 5 months after surgery and has been free from disease recurrence for more than 2 years. CONCLUSION: Thyroid storm after surgery is rare. However, this postoperative complication is important because it is fatal if not diagnosed and treated properly.

[Two elderly cases of transthyretin amyloid polyneuropathy without a family history].

We report two cases of transthyretin familial amyloid polyneuropathy (ATTR-FAP) from non-endemic areas. Both cases showed chronic progressive distal limb numbness and weakness. Due to nonspecific symptoms, they were not diagnosed for a long period of time. A nerve conduction study revealed axonal neuropathy in the lower limbs and carpal tunnel syndrome. An echo test showed thickness of the left ventricle, one of the red flag symptom clusters of ATTR-FAP. Genetic analysis revealed a mutation in the transthyretin gene. In cases with chronic progressive neuropathy, it is important to consider a differential diagnosis of ATTR-FAP.