From the Guidelines
Amyloidosis in the gastrointestinal tract manifests in various ways, including dysmotility, malabsorption, and bleeding, with common symptoms such as early satiety, nausea, vomiting, altered bowel habits, and pseudo-obstruction, as reported in the 2023 ACC expert consensus decision pathway on comprehensive multidisciplinary care for the patient with cardiac amyloidosis 1.
Manifestations of Amyloidosis in the GI Tract
The manifestations of amyloidosis in the GI tract can be categorized into several types, including:
- Mucosal involvement, which may lead to malabsorption or protein-losing enteropathy
- Neuropathic involvement, which may present primarily as GI dysmotility
- Vascular involvement, which may present with ischemia and bleeding
Common GI Symptoms
The most common reported GI symptoms of amyloidosis include:
- Early satiety
- Weight loss
- Abdominal pain
- Nausea
- Constipation
- Diarrhea These symptoms can be challenging to diagnose, as they may also be caused by other conditions, such as autonomic neuropathy or medication side effects 1.
Diagnosis and Treatment
Diagnosis of GI amyloid involvement typically requires tissue biopsy with Congo red staining, which shows characteristic apple-green birefringence under polarized light 1. Treatment focuses on managing the underlying condition causing amyloid production, with supportive care for specific GI symptoms as needed. This may include dietary modifications, such as a low FODMAP diet, and medications, such as antiemetics, prokinetics, and laxatives 1.
Management of GI Amyloidosis
Management of GI amyloidosis involves a multidisciplinary approach, including dietary modifications, medications, and supportive care. The goal of treatment is to manage symptoms, prevent complications, and improve quality of life. As reported in the 2023 ACC expert consensus decision pathway, there is currently no strong evidence that disease-modifying therapies for amyloidosis have an impact on GI involvement or symptoms 1.
From the Research
Manifestations of Amyloidosis in the GI Tract
The manifestations of amyloidosis in the GI tract can vary, but common symptoms include:
- Abdominal pain
- Dysmotility
- Diarrhea
- Gastrointestinal bleeding
- Hepatomegaly
- Portal hypertension with its associated complications 2
- Weight loss
- Autonomic dysfunction
- Malabsorption
- Proteinuria 2
Clinical Features
The clinical features of GI amyloidosis can be nonspecific, making diagnosis challenging. Common indications for biopsy include:
- Diarrhea
- GI bleed
- Abdominal pain
- Weight loss 3
- Endoscopic findings may show a fine granular appearance, erosions, ulcerations, mucosal friability, multiple protrusions, or tumor-like lesions 4
Diagnostic Challenges
GI amyloidosis can be misdiagnosed with several other diseases of the digestive tract, including:
- Inflammatory bowel disease
- Malignancy
- Ischemic colitis
- Collagenous colitis 4
- Amyloid colonic deposition may mimic these conditions, highlighting the need for Congo red staining and a positive sample with apple-green birefringence for definitive diagnosis 4, 5
Organ Involvement
The degree of organ involvement dictates the symptoms that a patient will experience. The small intestine usually has the most amyloid deposition within the GI tract, and liver involvement is seen in a majority of patients 5. Pancreatic involvement can lead to type 2 diabetes mellitus 5.
Treatment
Management of GI amyloidosis primarily aims to treat the underlying amyloid type with supportive measures to alleviate specific GI symptoms 5. Liver transplant is found to have positive outcomes, especially in patients with specific variants of hereditary amyloidosis 5. Disease modifying treatment with high-dose chemotherapy followed by autologous stem-cell transplantation has shown promise 2.