Objective and design

Fecal calprotectin (CLP) is widely known for its detection in stools of patients with inflammatory bowel diseases (IBDs), to investigate the intestinal inflammatory status. Current research is promoting the circulating protein role as a systemic inflammatory marker. However, most studies report serum calprotectin analysis although plasma assay prevents its massive release by granulocytes. In this perspective, the ongoing SARS-CoV-2 pandemic deserves deployment of convenient and easy-to-dose markers that could reliably address the state of infection.

Methods

We analyzed serum circulating calprotectin (cCLP) levels in hospitalized COVID-19 patients and plasma cCLP levels from patients with suspected SARS-CoV-2 infection, then assessed negative or positive on molecular tests.

Results

Our results confirm a significant circulating calprotectin increase in infected subjects respect to controls, in serum and plasma. Moreover, plasma calprotectin has higher levels in suspected patients with positive SARS-CoV-2-RT-PCR, compared to suspected patients with negative SARS-CoV-2-RT-PCR. Furthermore, ROC curves results showed the circulating plasma calprotectin discriminatory ability to differentiate infected SARS-CoV-2 patients at a cutoff value greater than 131.3 ng/ml.

Conclusions

Our data propose circulating calprotectin as a new, quantitative and predictive marker, which in addition to being an interesting generic inflammatory marker may provide important indications in SARS-CoV-2 infection.

中文翻译：

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循环钙卫蛋白作为区分 SARS-CoV-2 感染的支持性炎症标志物：一项观察性研究

目标与设计

粪便钙卫蛋白 (CLP) 因其在炎症性肠病 (IBD) 患者的粪便中检测以研究肠道炎症状态而广为人知。目前的研究正在促进循环蛋白作为全身炎症标志物的作用。然而，大多数研究报告了血清钙卫蛋白分析，尽管血浆测定可防止粒细胞大量释放钙卫蛋白。从这个角度来看，正在进行的 SARS-CoV-2 大流行值得部署方便且易于给药的标记物，这些标记物可以可靠地解决感染状态。

方法

我们分析了住院 COVID-19 患者的血清循环钙卫蛋白 (cCLP) 水平和疑似 SARS-CoV-2 感染患者的血浆 cCLP 水平，然后在分子检测中评估为阴性或阳性。

结果

我们的结果证实，相对于对照组，血清和血浆中受感染受试者的循环钙卫蛋白显着增加。此外，与 SARS-CoV-2-RT-PCR 阴性的疑似患者相比，SARS-CoV-2-RT-PCR 阳性疑似患者的血浆钙卫蛋白水平更高。此外，ROC 曲线结果显示循环血浆钙卫蛋白在大于 131.3 ng/ml 的临界值下区分感染的 SARS-CoV-2 患者的能力。

结论

我们的数据表明循环钙卫蛋白是一种新的、定量的和预测性的标志物，它除了是一种有趣的通用炎症标志物外，还可能为 SARS-CoV-2 感染提供重要的指示。