Image 1.
Renal interstitium is expanded by amyloid (amorphous pink) deposition (hematoxylin and eosin, kidney; original magnification, ×100).
Image 2.
Amyloid involving the renal glomeruli and interstitium (pink-orange amorphous deposits, nonpolarized; Congo red, kidney; original magnification, ×100).
Image 3.
Amyloid involving the renal glomeruli and interstitium (polarized yellow-green coloration of deposits) (Congo red polarized, kidney; original magnification, ×100).
Amyloidosis is a collective term for a debilitating and progressive disease characterized by the extracellular deposition of abnormal proteins. These abnormal proteins can either be deposited in a localized place, such as a single organ, or, as is the case with our patient, deposited throughout the entire body.
Unlike our patient, who was in his early 30s, the average age of patients diagnosed with AL amyloidosis is 65 years, and <10% of patients are younger than 50 years.1 Although bleeding disorders are associated with AL amyloidosis, our patient had coagulopathy caused by amyloidosis-induced acquired factor X deficiency, which is remarkably rare. In addition, our patient previously had idiopathic pancreatitis diagnosed, which was also eventually attributed to significant amyloidosis affecting the organ, based on autopsy pathology. A recent study conducted by Patel et al2 concluded that acquired factor X deficiency in AL amyloidosis is uncommon and is associated with advanced stage of disease. Although patients with factor X activity < 50% have higher risk for death, this is driven by stage rather than by bleeding events from low factor X levels.2
AL amyloidosis has a poor long-term prognosis when detected at an advanced stage because the median survival after diagnosis is generally less than 18 months.3 Our patient died within 2 months of diagnosis. Although his concurrent diastolic heart failure and end-stage kidney disease most likely contributed to his death, his clinical presentation demonstrates the inherent difficulty of developing prognostic models for patients with AL amyloidosis.
Article Information
Authors’ Full Names and Academic Degrees
Amaresh Vanga, MD, Ryan Cousins, MD, Malik Anjum, MD, and Varun Malhotra, MD.
References
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