A 47-year-old male patient suffered from recurrent
myalgia, induced by fasting or physical exercise. Later, he developed progressive
muscular weakness. Serum levels of
creatine phosphokinase (CPK) were elevated to approx. 400 U/1. Muscle biopsies showed
lipid storage myopathy and signs of acute fiber
necrosis, muscle
carnitine was decreased to below 20% of controls,
carnitine palmitoyl
transferase (
CPT) activity was normal.
Carnitine was also moderately decreased in a liver biopsy and in plasma. Urine excretion of
carnitine was low, no elevation of short-chain
dicarboxylic acids could be found. The patient was also found to suffer from a lymphocytic malignant
non-Hodgkin lymphoma, a monoclonal
immunoglobulin (Ig) G-k in plasma and lymphocytic infiltration of bone marrow were demonstrated. At that time no evidence had been obtained to indicate that these two diseases could be related to each other.
Autoantibodies against skeletal muscle could not be demonstrated. Absorption of
L-carnitine p.o. was normal, however, plasma levels of
carnitine fell again rapidly. Administration of 3 X 2 g
L-carnitine per day normalized the patient's plasma
carnitine levels and led to an increase of plasma short-chain
acylcarnitine and
ketone bodies, particularly
beta-hydroxybutyrate (B-HOB). However, no significant clinical improvement could be seen. Additional application of
prednisone led to normalization of CPK serum levels.