Changes of Peripheral Blood Lymphocyte Subsets and Cytokines in Patients with Multiple Myeloma and Their Clinical Significance

Objective: Accumulating evidence have indicated that immune response play an essential role in development of multiple myeloma (MM),To evaluate the immune function of patients with MM by detecting the levels of lymphocyte subsets and cytokines, and to analyze the correlation between the immune function and prognosis of patients. Methods: we examined 50 patients with newly diagnosed MM, 20 patients with Relapse / refractory MM and 30 healthy volunteers. the levels of T lymphocyte subsets, activated T cells subtypes, Treg and cytokines in peripheral blood were detected by flow cytometry (FCM).Results: ① compared with healthy control group, CD3 ⁺ CD4 ⁺ T cells of newly diagnosed MM patients were significantly decreased (P = 0.04), There was no significant difference in CD3⁺CD8⁺T and CD4/CD8 of newly diagnosed MM patients with normal controls (P=0.14).The percentage of CD16 + cd56^dim NK cells of newly diagnosed MM was significantly lower than that of the normal control group (P = 0.01); There was no significant difference in frequencies of CD3⁺CD4⁺T cells, CD4/CD8, CD16⁺CD56^dimNK (P=0.34, P=0.561, P=0.88) between newly treated MM patients and relapsed/refractory MM; HLA-DR-CD8+ activated T_S cells of newly diagnosed MM was significantly higher than the normal control group (P = 0.04).② The proportion of CD4 ⁺ CD25 ⁺ CD127^dim T cells(treg) in total CD4 ⁺ T cells in of newly diagnosed MM was higher than that in normal control group (P < 0.05). The CD4 ⁺ CD25 ⁺CD127^dim T cells of MM patients with relapse / refractory MM was higher than that of newly treated patients, but the difference was not statistically significant (P > 0.05). Further analysis showed that CD4 ⁺ CD25 ⁺ CD127^dim T cells in mSMART stratified high-risk group were higher than those in low-risk group (P = 0.03). The number of CD4 ⁺ CD25 ⁺ CD127^dim T cells in patients without PR after 2 courses of PAD was higher than that in patients with≥ PR, but the difference was not statistically significant (P > 0.05). ③ The levels of IL-6, IL-8, TNF - α of newly diagnosed MM were significantly higher than normal control group, and were positively correlated with ISS stage (r=0.61, r=0.67, r=0.59, P均<0.05).④ The levels of IL-6 and IL-8 of newly diagnosed MM with renal injury were significantly higher than those in patients with normal renal function (P < 0.05). Further studies showed that the level of IL-8 was negatively correlated with the proportion of CD16 ⁺ CD56^dimNK cells (r=-0.65, P<0.05).Conclusion: the abnormal expression of lymphocyte subsets and cytokine levels in MM patients may be related to the tumor load, disease progression and prognosis.