[The analysis of a severe side effect of a cartilage-protective agent by immunological studies]

After 18 intramuscular injections of Arumalon, a 62-year-old woman with degenerative hip-joint changes developed a severe illness with fever up to 39 degrees C, swellings of the finger, hand and knee joints, as well as a local skin rash and changes in the blood (WBC 1900/microliters, platelets 113,000/microliters), and increase in liver enzymes (GOT 83 U/l, GPT 93 U/l, lactate dehydrogenase 693 U/l). Arumalon, a glucosaminoglycan-peptide complex containing a watery extract of bovine cartilage and bone marrow, is used as a cartilage-protecting medication. The close temporal relationship between the injections and the symptoms suggested that the illness was drug-induced. This view was supported by a positive lymphocyte transformation test with Arumalon and its constituents, as well as by the demonstration of Arumalon-specific antibodies in the cultured lymphocyte fluid while the serum was negative for the antibodies. The illness took a protracted course. The patient became completely free of symptoms only after a year on a maintenance dose of prednisone, 15 mg daily. As a local inflammatory reaction was noted at the very start of the Arumalon injections, presensitization against the foreign proteins in Arumalon cannot be excluded. This is also supported by the fact that the specific lymphocyte proliferation was essentially unchanged even after nine months. This case illustrates the importance of careful assessment of increased and repeated manifestations of local reaction during Arumalon treatment, in particular in view of the risk of systemic side effects.