Renal amyloidosis overview

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief:

Historical Perspective

Nicolaus Fontanus was the first to describe amyloidosis based on the result of an autopsy while Rudolph Virchow was the first to intoduce the term amyloidosis.

Classification

Renal amyloidosis can be classified according to the site of amyloid deposition into glomerular, vascular, and tubular amyloidosis.

Pathophysiology

The kidney is the most involved organ in systemic amyloidosis. Suggested mechanisms of renal involvement include abnormal protein production or hereditary mutation.

Causes

Most common causes of renal amyloidosis include primary and secondary amyloidosis. Other causes include transthyretin and fibrinogen amyloid deposition.

Epidemiology and Demographics

The incidence is 9.7 to 14.0 cases per million person-years. The prevalence of AL amyloidosis was 40.5 in 2015, an annual percentage change (APC) of 12%. In renal amyloidosis, is usually first diagnosed in average age of 65 years and it is uncommon before age of 40.

Risk Factors

Common risk factors in the development of Renal amyloidosis may be environmental and genetic such as heterozygous mutations in the genes for lysozyme, apolipoprotein AI, apolipoprotein AII, or fibrinogen A alpha-chain.

Screening

There is insufficient evidence to recommend routine screening for renal amyloidosis.

Natural History, Complications, and Prognosis

If left untreated, renal amyloidosis may progress into end stage renal disease. Common complications include chronic renal failure and nephrotic syndrome. After a few years, renal amyloidosis eventually leads to end stage renal disease and it may be accelerated by some factors such as steroid administration, renal vein thrombosis, infections and surgery.

Diagnosis

Diagnostic Study of Choice

Biopsy is the gold standard test for the diagnosis of Renal amyloidosis

History and Symptoms

The majority of patients with Renal amyloidosis have proteinuria. Swelling is very common in lower limbs. Numbness or tingling in hands or feet (carpal tunnel syndrome) is a less common finding.

Laboratory Findings

In patients with secondary amyloidosis, urinalysis should be routinely examined. Laboratory findings consistent with the diagnosis of renal amyloidosis include proteinuria and increased serum creatinine

Electrocardiogram

There are no ECG findings associated with renal amyloidosis.

X-ray

There are no definitive findings on x-ray associated with renal amyloidosis.

Echocardiography and Ultrasound

There are no echocardiography/ultrasound findings associated with renal amyloidosis

CT scan

There are no CT scan findings associated with renal amyloidosis

MRI

There are no MRI findings associated with renal amyloidosis.

Other Imaging Findings

There are no other imaging findings associated with renal amyloidosis

Other Diagnostic Studies

Kidney biopsy can represent amyloid deposition as vascular, tubulo-interstitial and/or glomerular deposits. All types of amyloidogenic proteins show affinity for Congo red dye.

Treatment

Medical Therapy

The mainstay of treatment for Renal amyloidosis is to decrease the production or increase clearing of amyloid. Pharmacologic medical therapies for Renal amyloidosis include Colchicine, Azathioprine, Dimethylsulfoxide, Chlorambucil, Methotrexate, Cyclophosphamide andTNF-alpha antagonists (ie, etanercept, infliximab, and adalimumab).

Surgery

In renal amyloidosis, surgery is usually reserved for patients developed with end stage renal disease. The patients with renal amyloidosis are good candidates for transplantation. In primary amyloidosis, renal transplantation is considered and it will improve long-term survival and quality of life.

Primary Prevention

There are no established measures for the primary prevention of renal amyloidosis.

Secondary Prevention

Treatment of the primary disease and underlying cause will provide favorable renal outcome. Template:WikiDoc Sources