AA Amyloidosis in an Undomiciled Patient with IV Drug Use and Sepsis: A Diagnostic and Social Challenge in Progressive Kidney Failure

Introduction: AA amyloidosis is a systemic complication of chronic inflammation and is rarely reported in the U.S. in association with intravenous drug use (IVDU). In underserved populations, delayed access to care and overlapping comorbidities can obscure timely diagnosis. Case Description: A 45-year-old undomiciled male with a history of IVDU presented with three weeks of bilateral leg edema, weakness, abdominal pain, and poor hygiene. He was febrile and hypotensive on admission, with severe anemia, lactic acidosis, and acute kidney injury. Labs revealed positive hepatitis C viremia and nephrotic-range proteinuria. Renal ultrasound showed bilaterally echogenic kidneys. He was started on a bicarbonate infusion and empiric antibiotics for suspected sepsis. Dialysis was initiated via a temporary catheter. Kidney biopsy showed moderate to severe AA amyloidosis involving glomeruli and vessels, with patchy acute tubular injury and interstitial fibrosis. An arteriovenous fistula was ultimately placed, and the patient was discharged on chronic hemodialysis. Discussion: This case illustrates the diagnostic complexity and social barriers involved in managing advanced kidney disease in marginalized populations. Chronic inflammation from IVDU, recurrent infections, and active HCV likely contributed to AA amyloid deposition and progressive renal failure. The lack of early medical care delayed diagnosis until irreversible damage occurred. Biopsy was critical to confirming the etiology of nephrotic syndrome and guiding long-term dialysis planning. A multidisciplinary approach, including nephrology, infectious disease, psychiatry, and social support, was essential to navigating the patient’s clinical and behavioral challenges.Glomerular amyloid