Norwich Medical School, The University of East Anglia, Norwich, United Kingdom.
Norfolk and Norwich University Hospital NHS Foundation Trust, Norwich, United Kingdom.
J Breath Res. 2020 Dec 18;15(1):016016. doi: 10.1088/1752-7163/abb763.
Sarcoidosis is a chronic granulomatous disease of unknown aetiology with a variable clinical course and prognosis. There is an urgent need to identify new and novel biomarkers to help differentiate between clinical phenotypes and guide clinical decisions with respect to commencing and monitoring treatment. Across the spectrum of respiratory disease there has been a growing interest in the role of breath-based biomarkers given their non-invasive nature and ability to repeat sampling with ease for serial monitoring. Soluble interleukin-2 receptor (sIL2R) in bronchoalveolar lavage and serum correlates with disease activity in sarcoidosis; however, no previous study has evaluated sIL2R in exhaled breath.
The main aim of this cross-sectional case-controlled pilot study was to determine the concentration of sIL2R in exhaled breath condensate (EBC) from patients with recently diagnosed sarcoidosis compared to healthy volunteers and to establish, if present, if this correlated with markers of disease activity, pulmonary function tests and serological markers used in current clinical practice.
Paired serum and EBC samples were collected from twelve treatment naïve patients with histologically proven sarcoidosis diagnosed during the previous six months and compared to twelve healthy volunteers matched for age and gender.
Mean concentration of serum sIL2R was significantly elevated in participants with sarcoidosis compared to healthy controls (1584.3 ± 489.1 versus 874.2 ± 235.7 pg mL; p = 0.001). Soluble interleukin-2 receptor in EBC was detectable in only five subjects including three participants with sarcoidosis. The range of sIL2R across all five samples was 148.0-288.2 pg mL with the two highest concentrations observed in two participants with sarcoidosis. There was no significant difference observed in EBC sIL2R between sarcoidosis and healthy controls (p = 0.71). No apparent correlations were observed between EBC sIL2R and radiological stage, pulmonary function tests or serological markers.
Soluble interleukin-2 receptor is detectable in EBC; however, the findings from our study do not support its role as a diagnostic marker in sarcoidosis. Further research is required to evaluate its prognostic utility.
结节病是一种病因不明的慢性肉芽肿性疾病，其临床表现和预后差异较大。目前迫切需要寻找新的生物标志物，以帮助区分不同的临床表型，并指导临床决策，包括开始和监测治疗。在呼吸系统疾病中，由于呼吸生物标志物具有非侵入性和易于重复采样进行连续监测的特点，因此人们对其作用越来越感兴趣。支气管肺泡灌洗液和血清中的可溶性白细胞介素-2 受体（sIL2R）与结节病的疾病活动度相关；然而，之前没有研究评估过呼出气冷凝液（EBC）中的 sIL2R。
本横断面病例对照研究的主要目的是确定近期诊断为结节病的患者与健康志愿者相比，EBC 中 sIL2R 的浓度，并确定其是否与疾病活动的标志物、肺功能测试和目前临床实践中使用的血清学标志物相关。
收集 12 例经组织学证实的结节病患者（诊断时间在过去 6 个月内）的治疗前血清和 EBC 配对样本，并与 12 例年龄和性别相匹配的健康志愿者进行比较。
与健康对照组相比，结节病患者的血清 sIL2R 浓度明显升高（1584.3 ± 489.1 与 874.2 ± 235.7 pg/ml；p = 0.001）。只有 5 例患者的 EBC 中可检测到可溶性白细胞介素-2 受体，其中包括 3 例结节病患者。所有 5 个样本的 sIL2R 范围为 148.0-288.2 pg/ml，其中 2 例结节病患者的浓度最高。EBC sIL2R 在结节病患者与健康对照组之间无显著差异（p = 0.71）。EBC sIL2R 与放射学分期、肺功能测试或血清学标志物之间无明显相关性。
可溶性白细胞介素-2 受体可在 EBC 中检测到；然而，本研究的结果并不支持其作为结节病的诊断标志物。需要进一步研究以评估其预后价值。
