Patients with rheumatoid arthritis (RA) are more susceptible to infections, which elevate the levels of relative cytokines. However, the ability of the cytokines levels to predicate bacterial infections in RA patients remains unclear. Here, we assessed the ability of the combination of serum cytokine levels and blood parameters to diagnose bacterial infections in RA patients. We measured the levels of a panel of serum cytokine and blood parameters in 168 RA patients and 81 healthy individuals. RA patients were divided into the bacterial infection (INFE) group (n = 76) and RA flare without INFE group (n = 92). Bacterial infection was confirmed by microbial culture, imaging, antibiotic response, and typical clinical symptoms. The discriminative ability of the combination of the cytokine levels and inflammatory parameters was assessed using the receiver-operating characteristic (ROC) curves analysis and a novel bioscore system. The levels of interleukin (IL)-6 (p = 0.006), IL-10 (p = 0.019), interferon (IFN)-γ (p = 0.033), CRP (p < 0.001), and ESR (p < 0.001) were higher in patients of the INFE group than in patients with RA flare, and the absolute numbers of CD19+ B cells (p < 0.001) and CD4+ T cells (p = 0.009) were lower. For discriminating bacterial infection, the combination of IL-6, IL-10, IFN-γ, ESR, CRP, CD19+ B cells, and CD4+ T cells, provided an area under the curve (AUC) of 0.827 [(95% confidence interval (CI): 0.760-0.881)], which was profoundly larger than that of IL-6, IL-10, IFN-γ, ESR, CRP, CD19+ B cells, or CD4+ T cells alone. In addition, we also developed a bioscore system based on the combination of these seven biomarkers. Seventeen (100%) patients with a bioscore of 0 were non-infected, while seven (100%) patients with a score of 7 had bacterial infections. The bioscore based on the combination of ESR, CRP, IL-6, IL-10, IFN-γ, CD19+ B cells and CD4+ T cells may be a promising and robust tool to diagnose bacterial infections in RA patients.

中文翻译：

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多种细胞因子和血液参数综合分析诊断类风湿关节炎细菌感染

类风湿性关节炎 (RA) 患者更容易受到感染，从而提高相关细胞因子的水平。然而，细胞因子水平预测 RA 患者细菌感染的能力仍不清楚。在这里，我们评估了血清细胞因子水平和血液参数的组合诊断 RA 患者细菌感染的能力。我们测量了 168 名 RA 患者和 81 名健康个体的一组血清细胞因子和血液参数的水平。RA患者被分为细菌感染（INFE）组（n = 76）和没有INFE的RA发作组（n = 92）。通过微生物培养、影像学、抗生素反应和典型的临床症状证实细菌感染。使用受试者工作特征 (ROC) 曲线分析和新的生物评分系统评估细胞因子水平和炎症参数组合的辨别能力。白细胞介素 (IL)-6 (p = 0.006)、IL-10 (p = 0.019)、干扰素 (IFN)-γ (p = 0.033)、CRP (p < 0.001) 和 ESR (p < 0.001) 的水平INFE 组患者比 RA 发作患者更高，CD19+ B 细胞（p < 0.001）和 CD4+ T 细胞（p = 0.009）的绝对数量较低。为了区分细菌感染，IL-6、IL-10、IFN-γ、ESR、CRP、CD19+ B 细胞和 CD4+ T 细胞的组合提供了 0.827 的曲线下面积 (AUC) [（95% 置信区间(CI): 0.760-0.881)]，远大于单独的 IL-6、IL-10、IFN-γ、ESR、CRP、CD19+ B 细胞或 CD4+ T 细胞。此外，我们还开发了基于这七种生物标志物组合的生物评分系统。17 名 (100%) 生物评分为 0 的患者未感染，而 7 名 (100%) 评分为 7 的患者有细菌感染。基于 ESR、CRP、IL-6、IL-10、IFN-γ、CD19+ B 细胞和 CD4+ T 细胞组合的 bioscore 可能是诊断 RA 患者细菌感染的有前途和强大的工具。