Coronavirus SARS-CoV-2 spread worldwide, causing a respiratory disease known as COVID-19. The aim of the present study was to examine whether Dipeptidyl-peptidase 3 (DPP3) and the inflammatory biomarkers IL-6, CRP, and leucocytes are associated with COVID-19 and able to predict the severity of pulmonary infiltrates in COVID-19 patients versus non-COVID-19 patients. 114 COVID-19 patients and 35 patients with respiratory infections other than SARS-CoV-2 were included in our prospective observational study. Blood samples were collected at presentation to the emergency department. 102 COVID-19 patients and 28 non-COVID-19 patients received CT imaging (19 outpatients did not receive CT imaging). If CT imaging was available, artificial intelligence software (CT Pneumonia Analysis) was used to quantify pulmonary infiltrates. According to the median of infiltrate (14.45%), patients who obtained quantitative CT analysis were divided into two groups (> median: 55 COVID-19 and nine non-COVID-19, ≤ median: 47 COVID-19 and 19 non-COVID-19). DPP3 was significantly elevated in COVID-19 patients (median 20.85 ng/ml, 95% CI 18.34–24.40 ng/ml), as opposed to those without SARS-CoV-2 (median 13.80 ng/ml, 95% CI 11.30–17.65 ng/ml; p < 0.001, AUC = 0.72), opposite to IL-6, CRP (each p = n.s.) and leucocytes (p < 0.05, but lower levels in COVID-19 patients). Regarding binary logistic regression analysis, higher DPP3 concentrations (OR = 1.12, p < 0.001) and lower leucocytes counts (OR = 0.76, p < 0.001) were identified as significant and independent predictors of SARS-CoV-2 infection, as opposed to IL-6 and CRP (each p = n.s.). IL-6 was significantly increased in patients with infiltrate above the median compared to infiltrate below the median both in COVID-19 (p < 0.001, AUC = 0.78) and in non-COVID-19 (p < 0.05, AUC = 0.81). CRP, DPP3, and leucocytes were increased in COVID-19 patients with infiltrate above median (each p < 0.05, AUC: CRP 0.82, DPP3 0.70, leucocytes 0.67) compared to infiltrate below median, opposite to non-COVID-19 (each p = n.s.). Regarding multiple linear regression analysis in COVID-19, CRP, IL-6, and leucocytes (each p < 0.05) were associated with the degree of pulmonary infiltrates, as opposed to DPP3 (p = n.s.). DPP3 showed the potential to be a COVID-19-specific biomarker. IL-6 might serve as a prognostic marker to assess the extent of pulmonary infiltrates in respiratory patients.

冠状病毒 SARS-CoV-2 在全球范围内传播，引起一种称为 COVID-19 的呼吸道疾病。本研究的目的是检查二肽基肽酶 3 (DPP3) 和炎症生物标志物 IL-6、CRP 和白细胞是否与 COVID-19 相关，并能够预测 COVID-19 患者肺部浸润的严重程度。非 COVID-19 患者。我们的前瞻性观察研究纳入了 114 名 COVID-19 患者和 35 名非 SARS-CoV-2 呼吸道感染患者。在送往急诊室时采集了血样。 102 名 COVID-19 患者和 28 名非 COVID-19 患者接受了 CT 成像（19 名门诊患者未接受 CT 成像）。如果可以使用 CT 成像，则使用人工智能软件（CT 肺炎分析）来量化肺部浸润。根据浸润中位数（14.45%），将获得定量 CT 分析的患者分为两组（> 中位数：55 名 COVID-19 和 9 名非 COVID-19，≤ 中位数：47 名 COVID-19 和 19 名非 COVID -19）。与没有 SARS-CoV-2 的患者相比（中位值 13.80 ng/ml，95% CI 11.30-17.65），COVID-19 患者的 DPP3 显着升高（中位值 20.85 ng/ml，95% CI 18.34–24.40 ng/ml） ng/ml； p < 0.001，AUC = 0.72），与 IL-6、CRP（每个p = ns）和白细胞（ p < 0.05，但在 COVID-19 患者中水平较低）相反。关于二元 Logistic 回归分析，与 IL 不同，较高的 DPP3 浓度（OR = 1.12， p < 0.001）和较低的白细胞计数（OR = 0.76， p < 0.001）被认为是 SARS-CoV-2 感染的显着且独立的预测因子-6 和 CRP（每个p = ns）。 与浸润低于中位的患者相比，在 COVID-19（ p < 0.001，AUC = 0.78）和非 COVID-19（ p < 0.05，AUC = 0.81）中，浸润高于中位的患者的 IL-6 显着升高。与浸润低于中位的患者相比，浸润高于中位的 COVID-19 患者（每个p < 0.05，AUC：CRP 0.82，DPP3 0.70，白细胞 0.67）的 CRP、DPP3 和白细胞增加，与非 COVID-19 患者相反（每个p =纳秒）。关于 COVID-19 的多元线性回归分析，CRP、IL-6 和白细胞（每个p < 0.05）与肺部浸润程度相关，而不是 DPP3 ( p = ns)。 DPP3 显示出成为 COVID-19 特异性生物标志物的潜力。 IL-6 可作为评估呼吸系统患者肺部浸润程度的预后标志物。