[The significance of lactate dehydrogenase and beta 2-microglobulin levels for the assessment of the prognosis and choice of therapy in multiple myeloma].

Serum levels of lactate dehydrogenase (LDG) and beta 2-microglobulin (beta 2-MG) were measured in 164 and 128 patients with multiple myeloma (MM), respectively. High levels of LDG were recordable in 15.4% of patients at diagnosis and 36.8% of terminal stage patients. The frequency of extraosseous foci in untreated patients with high LDG activity made up 36.8%, survival median 19 months. In normal LDG activity the above values were 6.8% and more than 36 months, respectively. The highest LDG level occurred in patients with terminal plasmic cell leukemia. MM with IgD secretion was characterized by a a more frequent rise in LDG concentrations. Normal LDG amounts in active MM were seen in 58 (54.2%) out of 107 patients. beta 2-MG levels exceeded 6 mg/l in 75 of 128 patients with normal creatinine. These patients had a short survival median 24 months. Those patients who had beta 2-MG levels under 6 mg/l have not reached survival median for 36 months of follow-up. The authors hold that beta 2-MG concentrations are of prognostic value in all myeloma secretions and in nonsecretory myeloma as well though their indications are not absolute as 14% had low beta 2-MG levels in high MM activity. Comparative results are presented for 40 high-risk MM patients. Group 1 (20 patients) have received standard chemotherapy. Group 2 (20 patients) have undergone intensive polychemotherapy. Survival median made up 12 and 26 months for group 1 and 2, respectively.