Acute Renal Failure Due to Amyloidosis Associated With Intravenous Heroin Use.

Amyloidosis encompasses a group of disorders characterized by the accumulation of insoluble protein fibrils within the extracellular matrix. These fibrils originate from low molecular weight protein subunits, many of which circulate naturally in the bloodstream. The resulting deposits can occur in nearly any organ, with the clinical picture shaped by the type, distribution, and extent of amyloid involvement. Classification of amyloidosis is based on the identity of the precursor protein. Amyloid A (AA) amyloidosis, a systemic condition arising from chronic inflammation, is less common and most often linked to persistent inflammatory states, including chronic intravenous drug use. This case report describes a 54-year-old male with a history of injection heroin use who presented to the emergency department with a six-month history of progressive fatigue, exertional shortness of breath, and foamy urine. Laboratory evaluation revealed acute kidney injury (AKI), nephrotic range proteinuria, and significant anemia. A kidney biopsy confirmed the presence of AA-type amyloid deposits. AA amyloidosis is frequently observed in patients with autoimmune or chronic inflammatory conditions and has also been reported in individuals who engage in chronic intravenous and subcutaneous heroin use, known colloquially as "skin popping." Patients with subcutaneous heroin use carry a heightened risk of secondary amyloidosis, particularly affecting kidney function. Clinicians should maintain a high index of suspicion for AA amyloidosis in patients with a history of long-term IV drug use who present with proteinuria and AKI.