Biomarkers may be useful in monitoring disease activity in juvenile idiopathic arthritis (JIA). With new treatment options and treatment goals in JIA, there is an urgent need for more sensitive and responsive biomarkers. We aimed to investigate the patterns of 92 inflammation-related biomarkers in serum and saliva in a group of Norwegian children and adolescents with JIA and controls and in active and inactive JIA. In addition, we explored whether treatment with tumor necrosis factor inhibitors (TNFi) affected the biomarker levels. This explorative, cross-sectional study comprised a subset of children and adolescents with non-systemic JIA and matched controls from the Norwegian juvenile idiopathic arthritis study (NorJIA Study). The JIA group included individuals with clinically active or inactive JIA. Serum and unstimulated saliva were analyzed using a multiplex assay of 92 inflammation-related biomarkers. Welch’s t-test and Mann–Whitney U-test were used to analyze the differences in biomarker levels between JIA and controls and between active and inactive disease. We included 42 participants with JIA and 30 controls, predominantly females, with a median age of 14 years. Of the 92 biomarkers, 87 were detected in serum, 73 in saliva, and 71 in both biofluids. A pronounced difference between serum and salivary biomarker patterns was found. Most biomarkers had higher levels in serum and lower levels in saliva in JIA versus controls, and in active versus inactive disease. In serum, TNF and S100A12 levels were notably higher in JIA and active disease. The TNF increase was less pronounced when excluding TNFi-treated individuals. In saliva, several biomarkers from the chemokine family were distinctly lower in the JIA group, and levels were even lower in active disease. In this explorative study, the serum and salivary biomarker patterns differed markedly, suggesting that saliva may not be a suitable substitute for serum when assessing systemic inflammation in JIA. Increased TNF levels in serum may not be a reliable biomarker for inflammatory activity in TNFi-treated children and adolescents with JIA. The lower levels of chemokines in saliva in JIA compared to controls and in active compared to inactive disease, warrant further investigation.

中文翻译：

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幼年特发性关节炎的血清和唾液炎症生物标志物——一项探索性横断面研究

生物标志物可能有助于监测幼年特发性关节炎 (JIA) 的疾病活动性。随着幼年特发性关节炎的新治疗方案和治疗目标的出现，迫切需要更灵敏、反应更灵敏的生物标志物。我们的目的是调查挪威幼年特发性关节炎儿童和青少年、对照组以及活动性和非活动性幼年特发性关节炎儿童和青少年血清和唾液中 92 种炎症相关生物标志物的模式。此外，我们还探讨了肿瘤坏死因子抑制剂（TNFi）治疗是否影响生物标志物水平。这项探索性横断面研究包括患有非系统性 JIA 的儿童和青少年的子集以及来自挪威幼年特发性关节炎研究（NorJIA 研究）的匹配对照。JIA 组包括患有临床活动性或非活动性 JIA 的个体。使用 92 种炎症相关生物标志物的多重检测对血清和未刺激的唾液进行分析。Welch t 检验和 Mann–Whitney U 检验用于分析 JIA 和对照之间以及活动性疾病和非活动性疾病之间生物标志物水平的差异。我们纳入了 42 名患有幼年特发性关节炎的参与者和 30 名对照者，其中大多数是女性，中位年龄为 14 岁。在 92 种生物标志物中，87 种在血清中检测到，73 种在唾液中检测到，71 种在两种生物液中检测到。发现血清和唾液生物标志物模式之间存在显着差异。与对照组相比，幼年特发性关节炎患者血清中的大多数生物标志物水平较高，而唾液中的大多数生物标志物水平较低，活动性疾病与非活动性疾病相比。在 JIA 和活动性疾病中，血清中 TNF 和 S100A12 水平显着升高。当排除 TNFi 治疗的个体时，TNF 的增加不太明显。在 JIA 组唾液中，趋化因子家族的几种生物标志物明显较低，在活动性疾病中水平甚至更低。在这项探索性研究中，血清和唾液生物标志物模式存在显着差异，表明在评估幼年特发性关节炎全身炎症时，唾液可能不适合替代血清。血清中 TNF 水平升高可能不是 TNFi 治疗的 JIA 儿童和青少年炎症活动的可靠生物标志物。与对照组相比，幼年特发性关节炎患者唾液中的趋化因子水平较低，与非活动性疾病患者相比，活动期的趋化因子水平较低，值得进一步研究。