What Rheumatologists Need to Know about Identifying Amyloidosis

For AA amyloidosis, treatment options include chlorambucil, tumor necrosis factor–α inhibitors (they reduce proteinuria), colchicine, and eprodisate, although the last is investigational—eprodisate is a member of a new class of agents that interferes with interactions between fibril proteins and glycosaminoglycans.

For ATTR, treatment options include liver transplant (the liver being the site of the mutant transthyretin expression) and tafamidis. Tafamidis binds to transthyretin, preventing amyloidogenic aggregation. “Use of this drug resulted in a slower rate of worsening neurologic symptoms,” said Dr. Kay. Tafamidis has been approved for use in Europe, but is not yet approved by the U.S. Food and Drug Administration.⁸

For Aβ2M, treatment may include renal transplantation, which causes a reduction in symptoms due to increased Aβ2M clearance.

The key element of any treatment approach, said Dr. Kay, is timing. “These patients must be treated as early as possible in the disease course to minimize organ involvement.” It is hoped that with greater awareness of the clinical features and diagnosis of amyloidosis, improvements in therapy will finally make significant headway in managing this deadly disease.

Neil Canavan is a journalist based in New York.

References

1. Bardin T, Zingraff J, Kuntz D, Drüeke T. Dialysis-related amyloidosis. Nephrol Dial Transplant. 1986;1:151-154.
2. Merlini G, Bellotti V. Molecular mechanisms of amyloidosis. N Engl J Med. 2003;349:583-596.
3. Kyle RA, Linos A, Beard CM, et al. Incidence and natural history of primary systemic amyloidosis in Olmsted County, Minnesota, 1950 through 1989. Blood. 1992;79:1817-1822.
4. Kyle RA, Gertz MA. Primary systemic amyloidosis: Clinical and laboratory features in 474 cases. Semin Hematol. 1995;32:45-59.
5. Gertz MA, Li CY, Shirahama T, Kyle RA. Utility of subcutaneous fat aspiration for the diagnosis of systemic amyloidosis (immunoglobulin light chain). Arch Intern Med. 1988;148:929-933.
6. Kay J, Benson CB, Lester S, et al. Utility of high-resolution ultrasound for the diagnosis of dialysis-related amyloidosis. Arthritis Rheum. 1992;35:926-932.
7. Skinner M, Sanchorawala V, Seldin DC, et al. High-dose melphalan and autologous stem-cell transplantation in patients with AL amyloidosis: An 8-year study. Ann Intern Med. 2004;140:85-93.
8. Said G, Grippon S, Kirkpatrick P. Tafamidis. Nat Rev Drug Discov. 2012 ;11:185-186.