Antibody reactivities to skeletal muscle proteins in a patient with lambda light chain secreting multiple myeloma, generalised amyloidosis and rhabdomyolysis.

ABSTRACT

Rhabdomyolysis is a rare complication in haematological malignancies, and a diverse range of factors has been implicated in the etiology of the syndrome. In the present study we analysed muscle morphology and antibody reactivities to skeletal muscle proteins in a patient diagnosed with lambda (lambda) light chain-secreting multiple myeloma (MM) and amyloidosis, who developed a progressive rhabdomyolysis. The muscle tissue analysis showed focal amyloid depositions and a low degree of atrophy and inflammation. Antibody reactivities against muscle proteins of approximately 42, 51 and 66 kD, respectively, were present in the patient's serum. The antibody specificities were revealed by lambda light chain- or IgM-specific antibodies. The results indicate a possible etiologic link between antibody reactivities towards muscle proteins and muscle tissue disorder in a patient with the unique combination of rhabdomyolysis, amyloidosis and MM of the light chain type.