[Myopathy and mixed hyperlipoproteinemia as the first symptom of systemic AL-amyloidosis]

Systemic AL-amyloidosis is a disorder brought about by the over-production and deposition of fragments of light immunoglobulin chains in tissues, the consequence of which is their functional impairment. The most often affected are the kidneys, the heart, the gastro-intestinal tract and the nervous system. We describe the case of a 57-year-old patient in whom a rare disorder of the striated muscle (am yloid myopathy) was present, as the first clinical indication of systemic AL-amyloidosis. The main symptoms were muscle weakness and an increase in laboratory signs of muscle lesion. The patient was monitored for several years and treated with a diagnosis of primary idiopathic polymyositis (the likely diagnosis according to the diagnostic criteria of Bohan and Peter). Only after some years did hepatomegaly appear with elevated liver transaminases and a diagnosis of systemic AL-amyloidosis was established on the basis of a liver biopsy. By additional staining of striated muscle preparations with a dye for amyloid (in accordance with Maldyk) amyloid myopathy was confirmed. In addition to muscle affection, mixed hyperlipoproteinemia was present from the beginning. This was probably the first indication ofamyloidosis. The case description points out the justified inclusion of systemic AL-amyloidosis in differential diagnosis of muscle weakness and signs of muscle lesion. Amyloidosis must be considered if in addition to myopathy there is also present a problem with any organ which can typically be affected by amyloidosis.