ABSTRACT
Serum cholinesterase (ChE), red cell acetylcholinesterase (AChE), superoxide dismutase (SOD) and catalase were determined in 12 patients with multiple myeloma. Serum ChE was significantly depressed and bore a derect relationship with serum albumin concentration or Hb level. Red cell AChE was significantly elevated and showed a tendency of a reverse relationship with Hb. There was increased serum uric acid and 25% of the patients had serum uric acid over 9 mg/dl. Both SOD and catalase activities were found to be within normal limits, and showed no relationship with serum uric acid. These finding indicated that hyperuricemia occurs quite commonly in multiple myeloma patients with increased extracellular oxidants released from the degradation of purines to uric acid. However, these toxic oxidants could not overcome the antioxidant capacity of the red cells as indicated by a finding of normal SOD and catalase activities.