Zou Xing-Li, Lin Xiao-Jing, Ni Xun, Wang Jing, Liu Wen, Wei Jin
Clin Lab. 2016 Oct 1;62(10):1841-1850. doi: 10.7754/Clin.Lab.2016.160213.
Red blood cell distribution width (RDW) has been recently found to reflect systemic inflammation in addition to anisocytosis, and its value for assessing disease activity of systemic lupus erythematosus (SLE) has been addressed in two studies, but its correlation with therapeutic outcomes and disease flare has not been evaluated.
One hundred and ninety-six newly diagnosed patients with SLE (all-SLE), including 105 non-anemic patients (na-SLE) and 91 patients with anemia (a-SLE) were prospectively studied. Baseline RDW of SLE patients was compared with that of control subjects. Correlations between RDW and disease activity, traditional laboratory parameters, clinical features, therapeutic outcomes, and disease flare were examined.
RDW was exclusively higher in all-SLE, na-SLE, a-SLE than in controls (p < 0.001), but no significant difference of RDW was found between na-SLE and a-SLE (p = 0.27). More active disease scored with SLE Disease Activity Index 2000 (SLEDAI-2K) was present in patients with elevated RDW (> 15%) than normal RDW (= 11 - 15%) irrespective of anemia status (p < 0.001), and positive correlation between RDW with SLEDAI-2K was also disclosed independent of anemia status (r = 0.576, 0.614, 0.542, respectively for all-, na- and a-SLE, all with p < 0.001). Additionally, RDW positively correlated with high-sensitivity C-reactive protein (hsCRP) in all-SLE (r = 0.352, p < 0.001), na-SLE (r = 0.430, p < 0.001), and a-SLE (r = 0.315, p = 0.002). Among all clinical features, only the incidence of pulmonary arterial hypertension (PAH) was likely to be higher in elevated-RDW SLE than in normal-RDW SLE (χ2 = 4.135, p < 0.05). Patients received stratified therapy of remission induction based on their disease activity. A significantly higher rate of response (complete and partial response) was observed in normal-RDW than in elevated-RDW patients (all-SLE: 92.2% vs. 74.1%, p = 0.001; na-SLE: 92.3% vs. 77.5%, p = 0.04; a-SLE: 92% vs. 70.7%, p = 0.012). During a 12-month follow-up of the 166 responders, significantly greater flare-free survival was observed in normal-RDW than in elevated-RDW patients (68.8% vs. 29.8%, p = 0.002; 53.6% vs. 28.1%, p = 0.027; 55.9% vs. 31.4%, p = 0.032, respectively, for all-, na- and a-SLE).
Our findings suggest that baseline RDW is an easily available parameter not only capable of reflecting SLE overall activity, but also predicting therapeutic outcomes and the risk of disease flare irrespective of anemia status.
最近发现红细胞分布宽度（RDW）除反映红细胞大小不均一性外，还能反映全身炎症反应。两项研究探讨了其在评估系统性红斑狼疮（SLE）疾病活动度方面的价值，但尚未评估其与治疗效果及疾病复发的相关性。
前瞻性研究了196例新诊断的SLE患者（全部SLE患者），包括105例非贫血患者（非贫血SLE患者）和91例贫血患者（贫血SLE患者）。将SLE患者的基线RDW与对照组进行比较。检测RDW与疾病活动度、传统实验室指标、临床特征、治疗效果及疾病复发之间的相关性。
全部SLE患者、非贫血SLE患者、贫血SLE患者的RDW均显著高于对照组（p < 0.001），但非贫血SLE患者与贫血SLE患者的RDW无显著差异（p = 0.27）。无论贫血状态如何，RDW升高（> 15%）的患者与RDW正常（= 11 - 15%）的患者相比，系统性红斑狼疮疾病活动指数2000（SLEDAI - 2K）评分更高，提示疾病更活跃（p < 0.001），且RDW与SLEDAI - 2K呈正相关，与贫血状态无关（全部SLE患者、非贫血SLE患者、贫血SLE患者的r值分别为0.576、0.614、0.542，p均 < 0.001）。此外，全部SLE患者（r = 0.352，p < 0.001）、非贫血SLE患者（r = 0.430，p < 0.001）及贫血SLE患者（r = 0.315，p = 0.002）的RDW与高敏C反应蛋白（hsCRP）呈正相关。在所有临床特征中，仅肺动脉高压（PAH）在RDW升高的SLE患者中的发生率可能高于RDW正常的SLE患者（χ2 = 4.135，p < 0.05）。根据疾病活动度对患者进行分层诱导缓解治疗。观察到RDW正常的患者比RDW升高的患者有更高的缓解率（完全缓解和部分缓解）（全部SLE患者：92.2% 对74.1%，p = 0.001；非贫血SLE患者：92.3% 对77.5%，p = 0.04；贫血SLE患者：92% 对70.7%，p = 0.012）。在对166例缓解患者进行的12个月随访中，观察到RDW正常的患者比RDW升高的患者有更长的无疾病复发生存期（全部SLE患者、非贫血SLE患者、贫血SLE患者分别为68.8% 对29.8%，p = 0.002；53.6% 对28.1%，p = 0.027；55.9% 对31.4%，p = 0.032）。
我们的研究结果表明，基线RDW是一个易于获得的参数，不仅能够反映SLE的整体活动度，还能预测治疗效果及疾病复发风险，且与贫血状态无关。
