Systemic Amyloid A Protein Amyloidosis With Gastrointestinal Involvement

Systemic amyloidosis is a multiorgan deposition of misfolded amyloid protein fibrils. The systemic amyloid A protein (AA) amyloidosis type predominantly involves the kidney and is mostly an under-recognized complication among persons who inject drugs. Gastrointestinal involvement in systemic AA amyloidosis that is associated with illicit drug use is uncommon. In this report, we present a case of a 40-year-old man with history of injection drug use, recurrent skin and soft-tissue infection, and renal AA amyloidosis that presented with painless bloody bowel movement, which initially resolved with conservative management. Upon further evaluation, the patient was found to have empyema that required antibiotic therapy and bilateral pleural drain. His hospital course was further complicated by multiple episodes of hematochezia requiring gastrointestinal consultation. Subsequent gastrointestinal biopsy revealed amyloid deposit.