OBJECTIVETo investigate the effects of bortezomib(BTZ) and thalidomide(TM) on peripheral blood memory T-cells (T) and regulatory T cells(Tregs) in patients with multiple myeloma(MM).

METHODSEighty-six MM patients received 2 courses of chemotherapy were divided into effective (partial response at least) group (63 cases) and ineffective (no partial response) group (17 cases) according to therapeutic efficacy; these 80 patients were divided into BTZ group (38 cases) and TM group (42 cases) yet according to therapeutic regimens, 20 newly diagnosed MM patients were used as baseline group, 30 healthy volunteers were used as healthy control group. The T subsets and Treg in peripheral blood of each groups were detected by flow cytometry.

RESULTSThe CD4 central memory T cells (CD4 T) percentage of CD4 T, the CD18 T percentage of CD18T and ratio of CD8 T and CD8 effector memory T cells (T) (CD8 T/T) in baseline group were all significantly lower than those in healthy control group (P<0.05). After treatment with BTZ regimen or TM regimen, the CD8T percentage of CD8 T in effective group significantly increased to level of healthy control group (P<0.05); the Treg cell level in effective and in effective groups was not significantly different from that in baseline group(P>0.05), but the Treg percentage of CD4 cells ineffective group was significantly higher than that in baseline group and ineffective group (P<0.05). According to ROC curve, the critical value of CD8T/T for predicting chemotherapeutic response was 0.27 with sensitivity of 57.1% and specificity of 94.1%.

CONCLUSIONWhen MM patients are in an immuno-exhanstive status, the treatment with BTZ or TM both can reverse the immuno-inhibitory status of MM patients, moreover, does not affect the Treg cell count; the Treg percentage in BTZ and TM effective groups both are significantly higher than that in baseline group and ineffective group. The ratio of CD8T/T contributes to evaluating the chemotherapeutic efficacy.