Clinical significance of gastric food residue in gastrointestinal hereditary transthyretin amyloidosis

Background Hereditary transthyretin (ATTRv) amyloidosis is a systemic disorder caused by extracellular deposition of transthyretin-derived amyloid fibrils. Although gastrointestinal involvement is common, its endoscopic characteristics remain unclear. This study aimed to elucidate the endoscopic and histological features of gastrointestinal ATTRv amyloidosis.Methods Between January 2012 and August 2024, 123 patients with histologically and genetically confirmed gastrointestinal ATTRv amyloidosis who underwent esophagogastroduodenoscopy were retrospectively enrolled (GI ATTRv group). As controls, 123 age- and sex-matched individuals without amyloidosis were included.Results The GI ATTRv group comprised 77 men (62.6%) with a median age of 54 years. Amyloid deposition was most frequently observed in the muscularis mucosae (83.7%). More than half of both groups showed no abnormal endoscopic findings in the stomach (GI ATTRv: 61.8%, control: 62.6%; p = 1) or duodenum (GI ATTRv: 89.4%, control: 95.9%; p = .099). Gastric food residue was significantly more frequent in the GI ATTRv group than in controls (15.4% vs. 0.8%, p < .001).Conclusions Gastrointestinal ATTRv amyloidosis was characterized by a lack of specific endoscopic abnormalities. However, gastric food residue may represent a useful indicator of gastrointestinal dysmotility in ATTRv amyloidosis.