白细胞介素-15在狼疮性肾炎活动病变中的临床意义

目的：检测狼疮肾炎(LN)患者外周血白细胞介素15（IL-15）水平，并进一步分析其与临床有关指标的关系及治疗前后的变化。方法：用酶联免疫吸附法（ELISA）方法检测外周血IL-15水平；采用梯度密度离心法分离外周血单个核细胞(PBMCs)；并研究地塞米松对体外培养的活动期LN患者PBMCs分泌IL-15、IgG和dsDNA抗体的影响。结果：（1）LN组患者血清IL-15水平显著高于正常对照组(P<0.01)，活动期LN患者血清IL-15水平显著高于缓解期患者(P<0.05)。（2）活动期LN患者血清IL-15水平与SLE活动性指数(SLEDAI)、抗dsDNA抗体、24 h尿蛋白排泄量呈正相关关系，与补体C3呈负相关关系，而与血肌酐无相关关系。（3）激素联合环磷酰胺系统治疗活动期LN患者12周，治疗后随病情缓解血清IL-15水平明显下降。（4）体外培养的活动期LN患者PBMCs分泌IL-15、IgG、dsDNA抗体均显著高于正常对照组，而且IL-15分泌与dsDNA抗体和IgG合成呈正相关关系；地塞米松可明显抑制活动期LN患者PBMCs合成IL-15、IgG、dsDNA抗体。结论：LN患者外周血IL-15水平显著增高,IL-15可能参与LN的病理生理过程；血清IL-15水平检测可作为判断LN是否活动的指标之一。

Clinical significance of elevated serum interleukin 15 in patients with active lupus nephritis

AIM: To detect interleukin 15 (IL-15) levels in peripheral blood from patients with active lupus nephritis and investigate its clinical significance. METHODS: IL-15 level was determined by enzyme linked immunosorbent assay (ELISA). The peripheral blood mononuclear cells (PBMCs) were isolated with grads density abaxiality. The inhibitory effects of dexamethasone on production of IL-15, IgG and anti-dsDNA antibody in cultured PBMCs from LN patients were also investigated. RESULTS: (1) Serum IL-15 level in LN patients was significantly higher than that in normal controls (P<0.01). Serum IL-15 level in active LN patients was significantly higher than that in remised patients (P<0.05). (2) Serum IL-15 level was positively correlated with SLEDAI, anti-dsDNA antibody and 24 h urine protein excretion in active LN patients. (3) Serum IL-15 level was significantly reduced in LN patients treated with combination of cyclophosphamide (CTX) and steroid for 12 weeks. (4) Secretion of IL-15, IgG and dsDNA antibody in cultured PBMCs from active LN patients was significantly higher than that in normal control group, and IL-15 level in supernatant of cultured PBMCs from active LN patients was positively correlated with IgG and dsDNA antibody. Dexamethasone inhibited the secretion of IL-15, IgG and dsDNA antibody in cultured PBMCs from LN patients. CONCLUSION: Serum IL-15 level in patients with active lupus nephritis is significantly elevated, suggesting that IL-15 may be involved in the pathophysiological process of LN. IL-15 may be used as an index to assess the activity of LN.