OBJECTIVES A subset of human circulating FoxP3+ regulatory T cells expresses CD39 (cTreg39+) and hydrolyses pro-inflammatory adenine nucleotides released at inflammatory foci, rendering the anti-inflammatory agent adenosine. Methotrexate (MTX), inhibiting ATIC, enhances the extrusion of adenine nucleotides and may help Treg39+ cells control inflammation. Therefore, we examined the relation of cTreg39+ cells with the effect of MTX in early Rheumatoid Arthritis (eRA). METHODS Freshly isolated peripheral blood lymphocytes from 98 untreated eRA patients and 98 healthy controls (HC) were examined by cytometry. Twelve months (12m) after initiating MTX, 82 patients were clinically re-evaluated and cytometry was repeated in 40 of them. The effect of MTX on Treg cell potency was assessed in Treg/Tresp cocultures. RESULTS The baseline (0m) cTreg39+ cell frequency was elevated in eRA above HC levels. Patients who reached low disease activity at 12 months (12m-LDA, DAS28-ESR≤ 3.2, n = 51) had presented with a significantly higher 0m cTreg39+ frequency vs those who did not (n = 31). The 0m cTreg39+ cutoff for attaining 12 m-LDA was 42.0% (Sensitivity=90.4%/Specificity=96.8%). At 12m, the cTreg39+ frequency was no longer elevated but its association with disease activity remained: it was still significantly higher in patients who had reached LDA vs those who had not. In vitro, MTX augmented the Treg39+ cell potency but had no effect on Treg39- cells. CONCLUSION MTX cooperates with Treg39+ cells and the baseline cTreg39+ frequency predicts the response to MTX in eRA. In addition, the transiently elevated baseline cTreg39+ frequency in eRA may provide a slot for prompt MTX initiation.

中文翻译：

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短暂增加的循环 CD39+FoxP3+ Treg 细胞可预测早期类风湿关节炎对甲氨蝶呤的临床反应


目的 人类循环 FoxP3+ 调节性 T 细胞的一个子集表达 CD39 (cTreg39+) 并水解炎症灶处释放的促炎腺嘌呤核苷酸，从而产生抗炎剂腺苷。甲氨蝶呤 (MTX) 可抑制 ATIC，增强腺嘌呤核苷酸的排出，并可能帮助 Treg39+ 细胞控制炎症。因此，我们研究了 cTreg39+ 细胞与 MTX 在早期类风湿关节炎 (eRA) 中的作用的关系。方法 通过细胞计数法检查来自 98 名未经治疗的 eRA 患者和 98 名健康对照 (HC) 的新鲜分离的外周血淋巴细胞。开始 MTX 12 个月 (12m) 后，82 名患者接受了临床重新评估，其中 40 名患者重复进行了细胞计数。在 Treg/Tresp 共培养物中评估 MTX 对 Treg 细胞效力的影响。结果 eRA 中基线 (0m) cTreg39+ 细胞频率高于 HC 水平。与未达到低疾病活动度的患者 (n = 31) 相比，12 个月时达到低疾病活动度的患者 (12m-LDA、DAS28-ESR≤ 3.2，n = 51) 的 0m cTreg39+ 频率显着较高。获得 12 m-LDA 的 0m cTreg39+ 截止值为 42.0%（灵敏度=90.4%/特异性=96.8%）。 12m 时，cTreg39+ 频率不再升高，但其与疾病活动性的关联仍然存在：达到 LDA 的患者与未达到 LDA 的患者相比，cTreg39+ 频率仍然显着较高。在体外，MTX 增强了 Treg39+ 细胞的效力，但对 Treg39- 细胞没有影响。结论 MTX 与 Treg39+ 细胞协同作用，基线 cTreg39+ 频率可预测 eRA 中对 MTX 的反应。此外，eRA 中基线 cTreg39+ 频率短暂升高可能为迅速启动 MTX 提供了一个时机。