Clinical features and outcomes of systemic amyloidosis with gastrointestinal involvement: a single-center experience.

Background/aims: The gastrointestinal (GI) tract often becomes involved in patients with systemic amyloidosis. As few GI amyloidosis data have been reported, we describe the clinical features and outcomes of patients with pathologically proven GI amyloidosis.

Methods: We identified 155 patients diagnosed with systemic amyloidosis between April 1995 and April 2013. Twenty-four patients (15.5%) were diagnosed with GI amyloidosis using associated symptoms, and the diagnoses were confirmed by direct biopsy.

Results: Among the 24 patients, 20 (83.3%) had amyloidosis light chain (AL), three (12.5%) had amyloid A, and one (4.2%) had transthyretin-related type amyloidosis. Their median age was 57 years (range, 37 to 72), and 10 patients were female (41.7%). The most common symptoms of GI amyloidosis were diarrhea (11 patients, 45.8%), followed by anorexia (nine patients, 37.5%), weight loss, and nausea and/or vomiting (seven patients, 29.2%). The histologically confirmed GI tract site in AL amyloidosis was the stomach in 11 patients (55.0%), the colon in nine (45.0%), the rectum in seven (35.0%), and the small bowel in one (5.0%). Patients with GI involvement had a greater frequency of organ involvement (p = 0.014). Median overall survival (OS) in patients with GI involvement was shorter (7.95 months; range, 0.3 to 40.54) than in those without GI involvement (15.84 months; range, 0.0 to 114.53; p = 0.069) in a univariate analysis. A multivariate analysis of prognostic factors for AL amyloidosis revealed that GI involvement was not a significant predictor of OS (p = 0.447).

Conclusions: The prognosis of patients with AL amyloidosis and GI involvement was poorer than those without GI involvement, and they presented with more organ involvement and more advanced disease than those without organ involvement.