Laboratory findings of COVID-19: a systematic review and meta-analysis

The Coronavirus Disease (COVID-19) pandemic first broke out in December 2019 in Wuhan, China, and has now spread worldwide. Laboratory findings have been only partially described in some observational studies. To date, more comprehensive systematic reviews of laboratory findings on COVID-19 are missing. We performed a systematic review with a meta-analysis to assess laboratory findings in patients with COVID-19. Observational studies from three databases were selected. We calculated pooled proportions and 95% confidence interval (95% CI) using the random-effects model meta-analysis. A total of 1106 articles were identified from PubMed, Web of Science, CNKI (China), and other sources. After screening, 28 and 7 studies were selected for a systematic review and a meta-analysis, respectively. Of the 4,663 patients included, the most prevalent laboratory finding was increased C-reactive protein (CRP; 73.6%, 95% CI 65.0–81.3%), followed by decreased albumin (62.9%, 95% CI 28.3–91.2%), increased erythrocyte sedimentation rate (61.2%, 95% CI 41.3–81.0%), decreased eosinophils (58.4%, 95% CI 46.5–69.8%), increased interleukin-6 (53.1%, 95% CI 36.0–70.0%), lymphopenia (47.9%, 95% CI 41.6–54.9%), and increased lactate dehydrogenase (LDH; 46.2%, 95% CI 37.9–54.7%). A meta-analysis of seven studies with 1905 patients showed that increased CRP (OR 3.0, 95% CI: 2.1–4.4), lymphopenia (OR 4.5, 95% CI: 3.3–6.0), and increased LDH (OR 6.7, 95% CI: 2.4–18.9) were significantly associated with severity. These results demonstrated that more attention is warranted when interpreting laboratory findings in patients with COVID-19. Patients with elevated CRP levels, lymphopenia, or elevated LDH require proper management and, if necessary, transfer to the intensive care unit.新型冠状病毒病（Coronavirus Disease, COVID-19）大流行于2019年12月首次在中国武汉暴发，目前已在全球范围内扩散蔓延。既往部分观察性研究仅对其实验室检测结果进行了零星描述，截至当前，针对COVID-19实验室特征的全面系统综述仍存在空白。本研究开展了一项基于Meta分析的系统综述，旨在评估COVID-19患者的实验室检测结果。我们从三大数据库中筛选观察性研究，采用随机效应模型进行Meta分析，计算合并比例及95%置信区间（95% CI）。研究共从PubMed、Web of Science、中国知网（CNKI）及其他来源检索到1106篇文献，经严格筛选后，分别纳入28项研究用于系统综述、7项研究用于Meta分析。纳入分析的4663例患者中，最常见的实验室异常为C反应蛋白（C-reactive protein, CRP）升高（73.6%，95% CI 65.0–81.3%），其次为白蛋白降低（62.9%，95% CI 28.3–91.2%）、红细胞沉降率升高（61.2%，95% CI 41.3–81.0%）、嗜酸性粒细胞减少（58.4%，95% CI 46.5–69.8%）、白细胞介素-6升高（53.1%，95% CI 36.0–70.0%）、淋巴细胞减少（47.9%，95% CI 41.6–54.9%）及乳酸脱氢酶（lactate dehydrogenase, LDH）升高（46.2%，95% CI 37.9–54.7%）。针对7项研究共1905例患者的Meta分析显示，CRP升高（比值比OR=3.0，95% CI: 2.1–4.4）、淋巴细胞减少（OR=4.5，95% CI: 3.3–6.0）及LDH升高（OR=6.7，95% CI: 2.4–18.9）与疾病严重程度显著相关。本研究结果提示，临床实践中需加强对COVID-19患者实验室检测结果的解读与重视；CRP水平升高、淋巴细胞减少或LDH升高的患者需接受规范诊疗管理，必要时应转入重症监护病房（intensive care unit, ICU）。