AApoAII amyloidosis

AApoAII amyloidosis (also known as apolipoprotein A-II amyloidosis or hereditary renal amyloidosis due to apolipoprotein A-II variants) is a rare hereditary form of systemic amyloidosis caused by mutations in the APOA2 gene, which encodes apolipoprotein A-II. In this condition, variant apolipoprotein A-II protein misfolds and deposits as amyloid fibrils in various organs, most prominently the kidneys. The progressive accumulation of amyloid in renal tissue leads to chronic kidney disease, which may ultimately progress to end-stage renal failure. Amyloid deposits may also be found in other organs including the heart, liver, and spleen, though renal involvement is typically the dominant clinical feature. The disease usually presents in adulthood with proteinuria and progressive renal insufficiency. Patients may develop nephrotic syndrome, hypertension, and gradual decline in glomerular filtration rate over years to decades. The clinical course tends to be slowly progressive compared to some other forms of amyloidosis. Diagnosis is established through tissue biopsy demonstrating amyloid deposits, with immunohistochemical or mass spectrometry-based typing confirming apolipoprotein A-II as the amyloid fibril protein, combined with genetic testing revealing a pathogenic variant in the APOA2 gene. There is currently no specific disease-modifying therapy for AApoAII amyloidosis. Management is primarily supportive and focused on preserving renal function, controlling blood pressure, and managing proteinuria. Patients who progress to end-stage renal disease may require dialysis or kidney transplantation, although amyloid recurrence in transplanted kidneys has been reported. Genetic counseling is recommended for affected families given the hereditary nature of the condition.

Common questions about AApoAII amyloidosis