Techniques to Manage GI Involvement in Amyloidosis

Gastrointestinal (GI) tract involvement with amyloidosis has an array of manifestations, including weight loss, GI bleeding, and abnormal bowel habits. Light chain amyloidosis (AL) is the most common subtype of amyloidosis seen with GI tract involvement, but transthyretin amyloidosis cardiomyopathy (ATTR-CM) comprises 16% of GI amyloidosis cases.

In a series of patients with predominantly AL, abdominal pain, nausea, and vomiting accounted for half of GI complaints. In a registry of patients with ATTR-CM, unintentional weight loss was the most frequently reported symptom (28%), followed by early fullness (25%), and alternating diarrhea and constipation (23%). Treatment of amyloidosis involving the GI tract should be directed at the underlying process of amyloid fibril formation, with supportive care measures implemented in parallel to reduce GI symptoms and improve overall quality of life.

Poor nutritional status is common at the time of diagnosis; therefore, all patients with amyloidosis should undergo early assessment for malnutrition. Dietary supplements can be a valuable source of calories, with micronutrient monitoring and replacement recommended. Gastroparesis is generally managed with dietary modifications, specifically small, frequent meals with low soluble fiber and low-fat content, and nutritional supplementation can help avoid deficits.

Diarrhea is managed with antidiarrheals, particularly loperamide, which may bolster anal-sphincter function in patients with bowel incontinence. Standard measures should be taken for the treatment of constipation, including evaluation for drug-induced constipation and oral rehydration. When pharmacotherapy is needed, osmotic laxatives are first-line agents, with polyethylene glycol preferred over lactulose due to frequency of adverse events. Management of nausea, vomiting, abdominal bloating, and visceral pain should be modeled after treatment paradigms for severe functional GI disorders.

GI involvement in amyloidosis is often overlooked and requires appropriate clinical suspicion to be diagnosed. Quality of life in patients with GI-involved amyloidosis can be improved with supportive care measures and nutritional support. The complex multiorgan involvement often seen in patients with amyloidosis should be managed using a multidisciplinary approach, including gastroenterology, to achieve optimal patient outcomes.

Source

Fritz CDL, Blaney E. Evaluation and management strategies for GI involvement with amyloidosis. Am J Med. 2022;135(Suppl 1):S20-S23.