[Curative Efficacy of Rituximab for ITP Patients with Different Sensitivity to Hormone]

To investigatc the curative efficacy of low dose rituximab for glucocorticoid ineffective on dependent ITP patients and its relation with sensitivity to glucocorticoid so as to provide reference basis for rational use of drugs in clinical treatmant.

Seventy-ninth ITP patients enrolled in this study included the glucocorticoid-ineffective patients (19 cases) and glucocorticoid-dependent patients (60 cases). All ITP patients were treated with regimen consisted of high dose dexamethasone plus low dose rituximab (dexal-methasone 40 mg/d for 4 days per os, ritaximab 100 mg by intravenous infusion at D7, 14, 21 and 28 respectively). The patients after treatment were followed-up for 12 month, and the relation of patients sensitivity to glucocorticoid with therapentic response of rituximab was analyzed. The changes of Treg cell ratio and BAFF, IL-2 and sCD40L levels before and after treatment were detected by flow cytometry and ELISA respectively.

The overall response rate (ORR) of patients treated with above- mentioned regemen at 1, 3, 6 and 12 months after treatment was 79.7% (63/79), 69.6% (55/79), 63.3% (50/79) and 60.8% (48/79) respectivcly, out of which the ORR of glucocorticoid ineffective and glucocorticoid-dependent ITP patients treated with above-mentioned regimen at 1, 3, 6 and 12 months after treatment was 47.4% (9/19) vs 90.0% (54/60), 36.8% (7/19) vs 80.0% (48/60), 21.1% (4/19) vs 76.7% (46/60), 21.1% (4/19) vs 73.3% (44/60), and the difference between 2 groups was statistically significant. The detection of T reg cell showed that the T reg cell ratio in glucocorticoid- ineffective and dependent patients at 1, 3, 6 and 12 months after treatment was (1.70±0.43)% vs (3.47±0.72)%, (1.66±0.33)% vs (4.29±0.91)%, (1.71±0.37)% vs (4.44±0.97)%, (3.36±0.54)% vs (4.29±1.04)%, respectively. The detection of cytokines showed that the levels of BAFF, IL-2 and sCD40L in plasma of glucocorticoid-dependent patients at 1 month after treatment significanlly decreased (P＜0.05), the levels of BAFF, IL-2 and sCD40L in plasma of glucocorticoid-ineffective patients although decreased at 1 mouth after treatment, but there was no statistical difference as compared with glucocosticoid-depenment patients.

The treatment of glucocorticoid-dependent ITP patients with rituximab is more effective. The regulatory effect of rituximab on the T-reg cells, BAFF, IL-2 and sCD40L may be one of its mechanisms.