A Mysterious Trigger for Serum Amyloid A (SAA)-Associated Amyloidosis: Insights From an Autopsy Study.

Amyloidosis refers to a heterogeneous group of disorders characterized by the extracellular deposition of insoluble fibrillar proteins, leading to tissue damage and functional impairment. Among these, serum amyloid A (SAA) amyloidosis, previously termed secondary amyloidosis, arises in the context of chronic inflammatory conditions. While common causes include autoimmune diseases and chronic infections, the underlying etiology remains unidentified in a subset of cases. We report a rare case of SAA-associated amyloidosis in a 29-year-old male with a history of childhood-onset cystic bronchiectasis. The patient presented with progressive renal dysfunction and was diagnosed with systemic amyloidosis based on histopathological evaluation. Common autoimmune and infectious etiologies were excluded during life. An autopsy revealed alpha-1 antitrypsin deficiency as the underlying cause of chronic pulmonary inflammation, manifesting as cystic bronchiectasis, which likely triggered sustained elevation of serum amyloid A and subsequent amyloid deposition.