Introduction
Amyloidosis describes a group of diseases caused by the extracellular accumulation of misfolded serum proteins. Amyloidosis can affect all organs including the gastrointestinal (GI) tract. Symptoms like nausea, vomiting, diarrhoea, and abdominal pain suggest GI involvement of amyloidosis. Furthermore, GI amyloidosis is associated with a higher risk of gastrointestinal bleeding, especially when mucosal lesions are present.
Aims & Methods
Our study aimed to evaluate the frequency of GI manifestations in patients with amyloidosis, characterize these patients clinically, and describe the endoscopic and histopathologic findings in GI amyloidosis. A retrospective study was conducted at a German University Hospital, including a cohort of 61 patients with different types of amyloidosis between January 2004 and June 2022. Clinical, endoscopic, and histopathological data were retrieved from medical records and analysed.
Results
61 Patients with different types of amyloidosis were included in the study cohort. 23 (37.7%) displayed GI involvement. The median age of the patients with amyloidosis and gastrointestinal manifestation at diagnosis was 62 ± 18.28 years. 60.9% were male. Among the amyloidosis types, 52.5% were amyloid light chain (AL), 21.7% were transthyretin (TTR), 13.0% showed amyloid A (AA), and in 18% of the cases, the type was unknown. The gastrointestinal organs affected were mainly the colon (65.22%), stomach (30.4%), rectum (30.4%), duodenum (26.1%), and ileum (21.7%). Initial gastrointestinal symptoms were present in 78.3% of the patients and included mainly diarrhoea (34.8%), abdominal pain (30.4%), weight loss (26.1%), nausea/vomiting (21.7%), and loss of appetite (17.4%). Endoscopic findings were ulcerations (47.8%), mucosal inflammation (43.5%), polyps (26.1%), erosions (13.0%), vascular malformation, polypoid protrusion, submucosal haematoma, erythema, metaplasia, and diverticulum. Histopathological findings included thickening of the vessel walls, (peri-)vascular and interstitial amyloid deposits, and in one patient, a polyp with amyloid deposits. GI bleeding occurred in 39.1 % of the patients during the course of the disease. The mortality rate 5 years after diagnosis was 30.4%.
Conclusion
Amyloid tends to deposit in the gastrointestinal tract, which, being easily accessible, is often the target organ for a pathological diagnostic examination. However, amyloidosis of the gastrointestinal tract, with biopsy-proven disease, is rare. Due to the low incidence of this disease, the diagnosis of gastrointestinal amyloidosis may be overlooked. Furthermore, considering the existing literature, there is a paucity of data on GI amyloidosis. Therefore, clinicians must be aware of this manifestation when treating patients with amyloidosis, and if suspected, endoscopy with biopsy and histopathological examination should be performed.
