Serum Lactate Dehydrogenase Can Be Used as a Factor for Re-Evaluating First-Relapsed Multiple Myeloma

Background: Serum lactate dehydrogenase (LDH) is an adverse prognostic factor for newly diagnosed multiple myeloma (MM). However, the role of LDH in the prognosis of MM patients with relapse has not yet been thoroughly explored. Objectives: To explore the prognostic value of LDH in patients with first-relapsed MM. Methods: Data for 112 MM patients who had a first relapse between January 2012 and December 2017 were retrospectively reviewed. Patients were classified into two groups based on the level of serum LDH at relapse (≥240 and <240 U/L). Characteristics and outcomes of the two groups were compared. Results: During the first relapse, patients with high LDH levels had higher serum β 2 -microglobulin ( p = 0.001), lower serum albumin ( p = 0.006), lower platelet counts ( p < 0.001), and a higher percentage of extramedullary relapse ( p < 0.001) compared with patients with normal LDH levels. According to multivariate analysis, elevated serum levels of LDH ( p = 0.001) and re-ISS stage 2/3 ( p = 0.001) in relapsed MM patients were two key prognostic factors for overall survival. Conclusions: A high level of serum LDH at the time of first relapse may be a predictor of poor survival in relapsed MM patients.