[Expression of CD56 in Multiple Myeloma Cells and Its Relationship with Extramedullary Disease and Extramedullary Relapse].

Objective: To investigate the expression of CD56 in multiple myeloma (MM) cells and its relationship between extramedullary disease and extramedullary relapse.
Methods: Clinical data of 99 patients with MM treated in our hospital from January 2015 to December 2019 was retrospectively analyzed. The patients were divided into positive group and negative group according to the expression of CD56. The relationship between CD56 and multiple myeloma extramedullary disease, extramedullary relapse was analyzed.
Results: Among 99 newly diagnosed patients with MM, the positive rate of CD56 was 65%, and the incidence of extramedullary disease of patients in the CD56 positive group was lower than that in the CD56 negative group (17.19% vs 48.57%) (P<0.01). Meanwhile, the incidence of extramedullary relapse of patients in the CD56 positive group was lower than that in the CD56 negative group (1.56% vs 34.29%) (P<0.01).
Conclusion: CD56 is highly expressed in MM, and its low expression is associated with the occurrence of extramedullary disease and extramedullary relapse, which suggests that CD56 may be an important indicator for predicting the occurrence of extramedullary disease and extramedullary relapse.