Clinical approach of patients with systemic amyloidosis

Amyloidosis is the name of diseases characterised by deposition of protein fibrils with a beta-sheet structure. This beta-sheet structure generates affinity of amyloid for Congo red dye and is resistant to proteolysis. The main three types of systemic amyloidosis are AA (related to underlying chronic inflammation), AL (related to underlying monoclonal light chain production), and ATTR amyloidosis (related to old age or underlying hereditary mutations of transthyretin). Signs and symptoms vary among the three types and the treatment is different for each type. If a patient is suspected to have systemic amyloidosis, proof of the presence of amyloid in tissue must be obtained first and systemic involvement should be unequivocal. Determination of the precise type of amyloid is extremely important and one should start to detect the particular amyloid precursor. Assessment of size and function of vital organs and tissues is essential in the clinical work-up of a patient with systemic amyloidosis. A fast and thorough clinical evaluation is necessary to obtain all relevant information for prognosis and choice of treatment. The treatment is based on the “precursor-product” concept, in which the supply of amyloid precursor is the rate limiting step for further accumulation of amyloid. Effective therapy quickly and completely stops ongoing supply of precursor. In this respect, investigations such as serum amyloid P component (SAP) scintigraphy may help not only to investigate organ involvement but also response to treatment. The effects of therapy on both underlying disease and amyloidosis should be monitored frequently during follow-up