Amyloid Storm: An Uncommon Case of AA Amyloid Nephropathy

AA amyloidosis is a rare disease caused by tissue accumulation of serum amyloid A (SAA), a protein produced in the liver in response to chronic inflammation or infection. Kidney manifestations of AA amyloidosis usually develop gradually. The authors report a case of a 77­‑year­‑old patient with a previous diagnosis of multifactorial chronic kidney disease and bronchiectasis, who developed sudden onset nephrotic syndrome and KDIGO stage 3 acute kidney injury shortly after the diagnosis of acute pyelonephritis. A kidney biopsy confirmed the diagnosis of renal AA amyloidosis. Progressive kidney dysfunction ensued, with the need to begin kidney replacement therapy eleven months after the initial diagnosis. This type of renal AA amyloidosis (referred to as “amyloid storm”) has been reported in patients with familial Mediterra‑ nean fever but was not previously described in AA amyloidosis of other etiologies. The prognosis is poor, especially after dialysis initiation, and more studies are needed to develop strategies to delay its progression and improve outcomes.