[Amyloidosis]

The term amyloidosis refers to the extracellular deposition of fibrils composed of different types of plasma proteins. Various clinical symptoms are caused by the tissue damage related to the deposited fibrillary material. Except of the brain, all organs can be affected: kidney, liver, spleen, lung, gastrointestinal tract, endocrine organs, skin, heart and autonomous nervous system. Diagnosis is confirmed by specific histological methods (congo red stain, polarized and electron microscopy, immunohistochemistry) and genetic testing. Scintigraphy with radioisotope labeled serum amyloid P-component is helpful in the localization of the process and in the assessment of therapeutic effect. In the majority of cases the underlying disease is a plasma cell disorder, light chains aggregate to amyloid fibrils. Therefore chemotherapy and - in selected patients - stem cell transplantation is the choice of treatment. Another common type of amyloidosis is caused by chronic inflammatory diseases (amyloid fibrils are composed of elevated serum amyloid A being related to C reactive protein), or by some hereditary fever syndromes. Treatment of the underlying disorder may bring resolution of the amyloid burden. In 10% of the cases, amyloid fibrils are composed of genetically modified proteins. Depending on the source of the mutant protein liver transplantation, hepatorenal or cardiorenal transplantation may cure the disease.