Myopathy is a rare clinical manifestation in primary systemic amyloidosis. The clinical phenotype and muscle histology are well described but the pathophysiological mechanisms remain poorly understood. We report a 40-year-old man who presented with hypertrophic cardiomyopathy and a limb girdle syndrome associated with deposition of amyloid and free λ light chains in skeletal muscle. Electron microscopy showed amyloid fibrils, physically disrupting the plasma membrane and basal lamina, while laminin immunocytochemistry revealed a reduction of laminin β1 and upregulation of laminin α1. We believe that one of the possible pathophysiological mechanisms in amyloid myopathy is mechanical disruption of the sarcolemma by the abutting amyloid fibrils.
|Number of pages||4|
|Publication status||Published - 2002|
- Sarcolemmal damage