Further Outpatient Care
Ensure regular follow-up care with scrupulous attention to control of blood pressure.
Deterrence/Prevention
Genetic screening is possible for family members. Adequate counseling is a necessity because the age of onset and penetrance are highly variable and no specific treatment is available.
Prenatal diagnosis is technically possible but is of uncertain value because many individuals with these particular gene mutations have a normal life expectancy.
Complications
Acute kidney injury and chronic kidney disease can occur in the following forms of familial renal amyloidosis (FRA):
-
FRA due to variant lysozyme
-
FRA due to variant apolipoprotein AI
-
FRA due to variant apolipoprotein AII
-
FRA due to variant fibrinogen A alpha-chain
Acute and chronic liver failure can occur in the following forms of FRA:
-
FRA due to variant apolipoprotein AI
-
Potentially FRA due to variant lysozyme and fibrinogen A alpha-chain (very rarely)
The following complications can occur in these forms of FRA:
-
Restrictive cardiomyopathy - Some apolipoprotein AI and AII variants
-
GI hemorrhage/perforation - Lysozyme FRA
-
Progressive neuropathy - Some patients with apolipoprotein AI Gly26Arg and Leu178His
Prognosis
Many patients with FRA survive until the seventh decade or older, and most patients survive for at least 10 years after diagnosis. Life expectancy has increased substantially since kidney and liver transplantations have been introduced as treatments for these diseases. Liver transplantation is potentially curative in patients with fibrinogen A alpha-chain FRA and, possibly, in some patients with apolipoprotein AI amyloidosis.
Patient Education
Patient education should include the following:
-
Patients should be advised to avoid any potential systemic insults such as dehydration, nephrotoxic drugs, and avoidable general anesthetics or surgery.
-
Patients should not only be aware that first-degree relatives each have a 50% chance of carrying the gene but also that disease penetrance is highly variable.
-
For further information, see Mayo Clinic - Kidney Transplant Information.
-
Familial renal amyloidosis. Proposed mechanism for amyloid fibril formation. The drawing depicts a generic amyloid fibril precursor protein (1) in equilibrium with a partially unfolded, molten, globulelike form of the protein (2) and its completely denatured state (3). Autoaggregation through the beta domains initiates fibril formation (4), providing a template for ongoing deposition of precursor proteins and for the development of the stable, mainly beta-sheet, core structure of the fibril (5). The amyloidogenic precursor proteins in patients with familial renal amyloidosis are thought to be less stable than their wild-type counterparts, causing them to populate intermediate, molten, globulelike states more readily.
-
Familial renal amyloidosis. An extended kindred with hereditary amyloidosis associated with fibrinogen A alpha-chain Glu526Val; disease penetrance is high in this particular family.
-
Familial renal amyloidosis. Partial DNA sequence of the gene associated with fibrinogen A alpha-chain Glu526Val in a patient with familial renal amyloidosis, and a sequence from a healthy control. The mutation, which alters codon 526 from glutamic acid to valine, is marked with an arrow.
-
Familial renal amyloidosis. Progression of amyloid deposits in a patient with amyloidosis associated with fibrinogen A alpha-chain Glu526Val. These serial posterior, whole-body, scintigraphic images were obtained following intravenous injection of iodine-123 (123I)–labeled human serum amyloid P component into a 48-year-old man with hereditary amyloidosis associated with fibrinogen A alpha-chain Glu526Val in whom asymptomatic proteinuria had been identified. Both parents were alive and well and older than age 80 years. The scan at diagnosis (left) showed modest abnormal uptake into renal amyloid deposits, which increased at follow-up 3 years later (right). The remainder of the image represents a normal distribution of tracer throughout the blood pool.
-
Familial renal amyloidosis. Regression of amyloidosis associated with fibrinogen A alpha-chain Glu526Val following hepatorenal transplantation. The pictures are serial anterior, whole-body, scintigraphic images obtained following intravenous injection of iodine-123 (123I)–labeled human serum amyloid P component into a patient with amyloidosis associated with fibrinogen A alpha-chain Glu526Val. Prior to hepatorenal transplantation (left), heavy amyloid deposition was present in an enlarged liver and spleen. No amyloid deposits were identified in a follow-up study obtained 42 months after hepatorenal transplantation (right); only a normal distribution of tracer is present throughout the blood pool.
-
Familial renal amyloidosis. Regression of amyloidosis associated with apolipoprotein AI Gly26Arg following hepatorenal transplantation. These serial anterior, whole-body, scintigraphic images were obtained following intravenous injection of iodine-123 (123I)–labeled human serum amyloid P component into a patient with hereditary amyloidosis associated with apolipoprotein AI Gly26Arg. Prior to hepatorenal transplantation (left), heavy amyloid deposition was present in the liver, obscuring the kidneys. Two years after combined hepatorenal transplantation (right), a follow-up scan was normal, showing tracer distributed evenly throughout the background blood pool, including the transplanted organs. Splenic amyloid deposits that were evident initially in posterior scans had regressed at follow-up.