key: cord-0772519-vrsdi2p3 authors: Bao, Jingfeng; Li, Chenxi; Zhang, Kai; Kang, Haiquan; Chen, Wensen; Gu, Bing title: Comparative analysis of laboratory indexes of severe and non-severe patients infected with COVID-19 date: 2020-06-06 journal: Clin Chim Acta DOI: 10.1016/j.cca.2020.06.009 sha: 054faf70dc45ed2fa91ec7b6ab88a6ea5f23fed1 doc_id: 772519 cord_uid: vrsdi2p3 BACKGROUND: The pandemic coronavirus disease 2019 (COVID-19) has threaten the global health. The characteristics of laboratory findings of coronavirus are of great significance for clinical diagnosis and treatment. We found indicators that may most effectively predict a non-severe COVID-19 patient develop into a severe patient. METHODS: We conducted a meta-analysis to compare the laboratory findings of severe patients with non-severe patients with COVID-19 from searched articles. RESULTS: Through the analysis of laboratory examination information of patients with COVID-19 from 35 articles (5912 patients), we demonstrated that severe cases possessed higher levels of leukocyte (1.20-fold), neutrophil (1.33-fold), CRP (3.04-fold), PCT (2.00-fold), ESR (1.44-fold), AST (1.40-fold), ALT (1.34-fold), LDH (1.54-fold), CK (1.44-fold), CK-MB (1.39-fold), total bilirubin(1.14-fold), urea (1.28-fold), creatine (1.09-fold), PT (1.03-fold) and D-dimer (2.74-fold), as well as lower levels of lymphocytes (1.44-fold), eosinophil (2.00-fold), monocyte (1.08-fold), Hemoglobin (1.53-fold), PLT (1.15-fold), albumin (1.15-fold), and APTT (1.02-fold). Lymphocyte subsets and series of inflammatory cytokines were also different in severe cases with the non-severe ones, including lower levels of CD4 T cells (2.10-fold) and CD8 T cells (2.00-fold), higher levels of IL-1β (1.02-fold), IL-6 (1.93-fold) and IL-10 (1.55-fold). CONCLUSIONS: Some certain laboratory inspections could predict the progress of the COVID-19 changes, especially lymphocytes, CRP, PCT, ALT, AST, LDH, D-dimer, CD4 T cells and IL6, which provide valuable signals for preventing the deterioration of the disease. Since December 2019, the rapid propagation of a novel coronavirus (SARS-CoV-2) has broken out in China, and SARS-CoV-2 causes a novel pneumonia named COVID-19 [1] . SARS-CoV-2 is a β-coronavirus with a genome highly homologous to bats, which probably originated from wild animals [2] . Interpersonal transmission is the main cause of infection [3] . The World Health Organization (WHO) has declared it as a public health emergency of international concern [4] . As of May 3, 2020, a total of 3405914 cases were confirmed and 240573 cases died globally [5] . The clinical features of severe COVID-19 are similar to those of severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS). It can cause acute respiratory distress syndrome (ARDS), acute heart injury, and even death. Its main clinical features are fever, cough and sore throat. According to the clinical classification method, the patients were divided into four types: ordinary type, mild type, severe type and critically ill type according to the severity of the disease [6, 7] . In addition, the correlation between specific laboratory diagnosis and disease severity deserves attention. Several studies have reported different laboratory findings at the beginning of the outbreak of COVID-19 [8] [9] [10] . The purpose of this survey is to reveal the characteristics of laboratory findings of COVID-19 through the included articles, especially the changes of severe and critically ill patients, so as to provide more information for COVID-19 's diagnosis. PubMed and Web of Science were used to search for related articles. The key words are "2019-nCoV" "COVID-19" "SARS-CoV-2" "clinical characteristics" and "laboratory findings". To ensure the comprehensiveness and accuracy of the study, we also consulted the references of the included literature. The searches were performed three times to identify articles published before April 27, 2020. Then we screen the articles according to the abstract, eliminate the articles that obviously do not meet the inclusion criteria, and then read the full text for re-screening. Articles that provided values of laboratory indicators for severe and non-severe patients, including blood routine, inflammatory factors, biochemical and immune-related indexes were included. Pre-printed articles are also included. rticles published repeatedly, translated articles, studies did not include the laboratory indicators needed for meta-analysis; research data were missing were excluded. In addition, conference summaries, reviews and meta-analysis were excluded. Statistically analyzed the data related to laboratory indexes (blood routine, inflammatory markers, biochemical detection indexes, blood coagulation function and immune indexes) to compare the differences between severe and non-severe patients and summarize indicators with statistical significance and clinical value. These laboratory indicators were usually showed as the mean and standard deviation, but sometimes were median and interquartile range (IQR). The sample mean was estimated by Luo et al.'s method [11] and variance by Wan et al.'s [12] from the sample size, median and IQR. For these laboratory indexes, the inverse variance method for pooling was used to calculate the overall mean from studies reporting a single. The I 2 statistic is a test used to quantify heterogeneity and values of I 2 >50% indicated that heterogeneity existed. When statistical heterogeneity was identified, the random effects model will be used. The meta package (ver 4.11-0; https://cran.rproject.org/) was used to conduct the overall mean. In addition, we analyzed the correlation and regularity of diverse laboratory indexes in patients with COVID-19 to find the considerable advantages of combined analysis in the diagnosis and treatment of patients' condition. We will apply the following criteria to assess the risk of bias for each included study. The project score is 0 (not reported), 1 (reported but insufficient), or 2 (reported and sufficient). The global ideal score for non-comparative studies is 16. In addition, we will draft funnel-plots for laboratory indicators with significant differences between severe and non-severe patients with COVID-19 if there are sufficient included studies (at least 10) and observe the symmetry of the funnel-plots to judge the publication bias. The process of study selection is displayed in Fig 1. A total of 715 publications were retrieved, including 645 articles on PubMed, 70 articles on Web of Science. Among these studies, 65 records were excluded due to duplication of records/titles. 615 were removed because they did not meet the inclusion criteria based on title and/or abstract. Finally, we obtained the laboratory test results of 35 articles describing 5912 COVID-19 confirmed patients (up to May, 2020). The basic characteristics of the articles included in the study are shown in Table 1 . Among these articles, 34 articles described the results of blood routine and infection-related biomarkers, 26 articles described the results of biochemical tests, 23 articles provided test results for blood coagulation and 5 articles described the results of immunoassay. A total of 5,912 patients (mean age:54.80；95%CI (52.50-57.20) ), including 4337 non-severe patients (mean age:48.50；95%CI (45.70-51.30) ) and 1663 severe patients (mean age:61.00；95%CI (59.10-62.90)). More than half of them were male (3072/5912(51.96%)). 2531 of these patients with underlying disease, including hypertension, diabetes, cardiovascular disease, cerebrovascular disease, chronic obstructive pulmonary disease (COPD), chronic kidney disease and liver disease, Malignant tumors and patients with low immunity. Based on the comprehensive collation of the laboratory data provided in the selected 35 articles, the average value and variation range of various indexes of total patients, non-severe patients and severe patients were obtained and shown in Table 3 . In addition, the Funnel plot of important laboratory indicators are shown in Figs 2-10. Increased C-reactive protein (CRP) concentration appeared in 57.40% Our statistics showed that the related indexes of myocardial injury increased in different numbers of patients with COVID-19. (respectively creatine kinase (CK) The increase of alanine aminotransferase (ALT) (12.27% (296/2412)) and AST The increase of creatinine (2.41% (40/1659)) and urea (13.50% (47/348)) were observed among the included patients with COVID-19. Besides, albumin reduction The values of antibodies and complements in blood serum in Qin's [13] study showed that immunoglobulins (IgA, IgG and IgM) and complement proteins (C3 and C4) of COVID-19 patients are within the normal range. Compared with the nonsevere group, the IgM of the severe group was only slightly decreased, and there was no significant difference in other immunoglobulins and complement, which was consistent with the results of Feng's study [14] . The total number of B cells, T cells and NK cells significantly decreased in patients with COVID-19 (852.9 /uL), and more evident in the severe cases (1.37-fold; 743.6 vs 1020.1 /uL; P = 0.032) compared to the non-severe group [13] . [13] . Studies also reported that GSCF, IP-10, MCP1and MIP1A in severe patients were higher [10] . Judging by the evaluation score, all of the included articles were classified as high quality and there was no considerable publication bias ( Table 2 ). The quality assessment graph and the reporting bias of important laboratory indicators are exhibited in Supplementary materials. In 21 critically ill patients with COVID-19 in Washington State, 67% and 38% of these patients had lymphopenia and abnormalities of liver function tests at admission respectively [19] . Higher concentrations of IL-6 and D-dimer at admission were independently associated with in-hospital mortality, which has been confirmed in 1150 patients in New York [20] . On a cohort of 300 COVID-19 patients from Italy, patients demonstrated lymphopenia in many cases [21] . In another group of Italian cases, the frequency of granulocyte morphological anomalies has been highlighted, especially in patients with severe ARDS at admission [22] . The values of leukocyte, IL-6, LDH, CK and D-dimer continued to increase in 50 COVID-19 patients with ARDS during hospitalization in a German report [23] . About Singapore, lymphopenia was present in 39% patients (7/16) and an elevated CRP in 38% patients (6/16), while kidney function remained normal [24] . Lower blood counts of leukocytes, platelets, neutrophils, lymphocytes, eosinophils, and basophils (all P < 0.001) in COVID-19 patients were significant predictors of SARS-CoV-2 positive test [25] . In addition, compared with less severe diseases, CRP is higher and the lymphocyte count is lower has been found in a study in Norway [26] . Overall, we found that foreign patients have similarities to the changes in laboratory indicators of Chinese patients, typically including a decrease in leukocytes and lymphocytes and an increase in inflammation-related factors. The abnormality of blood coagulation, liver and kidney function and immune function also appeared in foreign patients, especially in severe and critically ill patients. However, due to differences in viral gene variation and detection time, the diversity in the laboratory indicators of patients around the world is inevitable, and more data required to confirm. Facing the huge threat of COVID--19 to human health, laboratory evaluation and early prediction of patients' condition should be paid to more attention. At present, the characteristics of laboratory examination results of hospitalized patients were reported, but the discrepancies were observed between these reports due to the different proportions of severe patients in each study. Among 5912 patients who underwent laboratory examinations on admission, lymphopenia was typical, which might be risk factors for disease progression of COVID-19 [27] . The PLT-to-lymphocyte ratio (PLR) and the neutrophil/lymphocyte ratio (NLR) may provide new indexes for the monitoring the changes of patients with COVID-19 [28] [29] [30] . The NLR was >5 in severe patients critically ill patients, proving that severe patients are more likely to develop leukocytosis and lymphocytopenia [29] . Neutrophils and eosinophils may be used to predict the recovery probability [31, 32] . The decrease of hemoglobin and PLT were significantly associated with the severity of the disease [33, 34] . In addition, the combined parameter NLR&RDW-SD can help clinically to predict the severity of COVID-19 patients [35] . In conclusion, blood routine examination is of great value in the diagnosis and prognosis of COVID-19. High infection-related biomarkers (i.e. PCT, ESR, and CRP) have been observed in our study. CRP is a good predictor of adverse consequences and related to inflammation of tissues and organs [36] [37] [38] . A simple death risk index (ACP) consisting of age and CRP was developed by Lu et al [39] , by which the short-term mortality associated with COVID-19 can be predicted. Higher serum hypersensitive C-reactive protein (hs-CRP) is an important marker of poor prognosis in COVID-19 patients and can be used to predict the risk of death in severe patients, which reflects the persistent state of inflammation [40] . Increased PCT, SAA and ESR were identified as powerful factors to predict disease progression of patients with COVID-efficiency of predicting the development of patients' condition [45] . On account of the common co-infection in children, the increase of PCT is more obvious than that in adults, so it should be used as an important index for the detection of children [46] . Thus, infection-related biomarkers are risk factors for disease progression. In term of biochemical indicators, patients with organ dysfunction, (including ARDS, acute renal injury, heart injury, liver dysfunction, pneumothorax, etc.) are prone to exhibit abnormal results of blood biochemical examination [47] . Increased serum N-terminal proB-type natriuretic peptide (NT-proBNP), cardiac troponin-I (cTnI), myoglobin and creatinine were related factors of critical COVID-19 with heart damage [48, 49] . Cardiac injury defined by the increase of hs-cTnI and D-dimer on admission and patients with high BNP is associated with a higher risk of mortality [50, 51, 52] . LDH, AST/ALT ratio, TBIL could be identified as powerful predictive factors for early recognition of liver injury and were positively correlated with death risk of COVID-19 patients [53] [54] [55] . Albumin, serum urea nitrogen and creatine were risk factor s for assessing kidney damage and disease progression [55, 56] . Many patients have abnormal urine analysis on admission, including proteinuria or hematuria, which indicates that urine analysis can better reveal the potential kidney damage of COVID-19 patients to reflect and predict the severity of the disease [57, 58] . In short, the cardiac biomarkers, liver and kidney function examination for severe and critically ill patients can evaluate the degree of extrapulmonary damage caused by complications. Furthermore, the level of lactic acid, plasma angiotensin II, amylase and lipase can also be used as indicators to estimate the course of the disease [49, 59] . Plasma angiotensin II level linearly correlated with virus titer and the degree of lung injury was increased in one study [49] . Other than the high expression of angiotensinconverting enzyme 2 (ACE2) in the pancreatic tissue of COVID-19 patients, the increase of serum amylase and lipase were found [60] . In addition, the detection of electrolyte and blood glucose indexes is of great significance for patients with underlying diseases of electrolyte balance disorder and glucose metabolism disorder. The changes in blood coagulation, especially disseminated intravascular coagulation (DIC), which is common in critical diseases, should also been paid enough attention [61] [62] [63] [64] . Severe patients may exhibit blood coagulation disorders, including increased D-dimer, prolonged PT and shortened APTT, which is consistent with reports [62, 63] . D-dimer is associated with the severity of COVID-19 [65] . Fibrinogen can be significantly increased in the early stages of severe patients, but notably decreased in the later stages, this may be the reason why serious people are more likely to suffer from cerebrovascular disease [66, 67] . Bleeding and coagulation dysfunction and even DIC combined with COVID-19 is a process of dynamic change. Monitoring the blood coagulation function of patients is beneficial to the early diagnosis, prevention and treatment of the disease. In addition, The combined detection of IL-6 and D-dimer had important clinical value for early prediction of the severity of COVID-19 patients due to its high sensitivity and specificity [68] . Our analysis showed that lower levels of CD4 and CD8 and higher levels of inflammatory cytokines (IL-1β, IL-6, IL-10) in severe patients, which made important impacts in predicting the state of the illness changes from mild to severe. The decrease of CD4 and CD8 in peripheral blood and the increase of IL-6 are the highrisk factors of cytokine release syndrome-like (CRSL) [59, 69, 70] . CD3+T cells, IP-10, MCP-3 and IL-1ra were also closely related to the severity and progression of COVID-19 [54, 71] . Diao et al. [69] found that the number of T cells was negatively correlated with the concentration of serum IL-6, IL-10 and TNF-α. In addition, the immune response phenotype based on late IgG response can be used as a simple complementary tool to distinguish between severe and non-severe COVID-19 patients and to further predict their clinical outcomes [72] . Overall, close monitoring of the T lymphocyte subsets and cytokines might provide valuable information on the patient's condition change during the treatment process [73] . Although our analysis showed the characteristics of laboratory findings of COVID-19 patients, relatively few patients were included in the analysis. In addition, the recruited participants in our study were hospitalized before April 27, 2020 and more laboratory tests of COVID-19 patients should be investigated. Covid-19: WHO declares pandemic because of "alarming levels" of spread, severity, and inaction A pneumonia outbreak associated with a new coronavirus of probable bat origin Early Transmission Dynamics in Wuhan, China, of Novel Coronavirus-Infected Pneumonia World Health Organization.Statement on the second meeting of the International Health Regulations (2005) Emergency Committee regarding the outbreak of novel coronavirus Coronavirus COVID-19 Global Cases Guidelines for the diagnosis and treatment of novel coronavirus (SARS-CoV2) infection (trial version 7) 2020 Clinical management of severe acute respiratory infection when Novel coronavirus (nCoV) infection is suspected: Interim Guidance Clinical characteristics and intrauterine vertical transmission potential of COVID-19 infection in nine pregnant women: a retrospective review of medical records Clinical characteristics of novel coronavirus cases in tertiary hospitals in Hubei Province Clinical features of patients infected with 2019 novel coronavirus in Optimally estimating the sample mean from the sample size, median, mid-range, and/or mid-quartile range Estimating the sample mean and standard deviation from the sample size, median, range and/or interquartile range Dysregulation of immune response in patients with COVID-19 in Clinical characteristics of 30 medical workers infected with new coronavirus pneumonia Clinical characteristics and prognosis in cancer patients with COVID-19: A single center's retrospective study Suppressed T cell-mediated immunity in patients with COVID-19: A clinical retrospective study in Wuhan Epidemiological characteristics and clinical features of 32 critical and 67 noncritical cases of COVID-19 in Chengdu Characteristics and associations with severity in COVID-19 patients: a multicenter cohort study from Jiangsu province Characteristics and Outcomes of 21 Critically Ill Patients With COVID-19 in Washington State Epidemiology, clinical course, and outcomes of critically ill adults with COVID-19 Hospital at the time of the COVID-19 outbreak: letter from the warfront Morphological anomalies of circulating blood cells in COVID-19 infection The characteristics of 50 hospitalized COVID-19 patients with and without ARDS Epidemiologic Features and Clinical Course of Patients Infected With SARS-CoV-2 in Epidemiological and Clinical Predictors of COVID-19 Covid-19: Symptomer, forløp og bruk av kliniske skåringsverktøy hos de 42 første pasientene innlagt på et norsk lokalsykehus The clinical characteristics of COVID-19: a retrospective analysis of 104 patients from the outbreak on board the Diamond Princess cruise ship in Japan, medRxiv Platelet-to-lymphocyte ratio is associated with prognosis in patients with Corona Virus Disease-19 Neutrophil-to-Lymphocyte Ratio Predicts Severe Illness Patients with Early Prediction of Disease Progression in 2019 Novel Coronavirus Pneumonia Patients Outside Wuhan with CT and Clinical Characteristics, medRxiv Longitudinal analysis of laboratory findings during the process of recovery for patients with COVID-19, medRxiv Laboratory Parameters in Detection of COVID-19 Patients with Positive RT-PCR; a Diagnostic Accuracy Study Hemoglobin value may be decreased in patients with severe coronavirus disease Delayed-Phase Thrombocytopenia in Patients of Coronavirus Disease Preliminary study to identify severe from moderate cases of COVID-19 using NLR&RDW-SD combination parameter, medRxiv Prognostic value of C-reactive protein in patients with COVID-19, medRxiv Cardiovascular Implications of Fatal Outcomes of Patients With Coronavirus Disease Risk factors related to hepatic injury in patients with corona virus disease Prediction of criticality in patients with severe Covid-19 infection using three clinical features: a machine learning-based prognostic model with clinical data in Wuhan medRxiv Potential Factors for Prediction of Disease Severity of COVID-19 Patients, medRxiv Clinical features and outcomes of 221 patients with COVID-19 in Clinical Hallmarks of 13 COVID-19 Patients Revealing SAA Biomarker Serum Amyloid A Protein as a Potential Biomarker Useful in Monitoring the Course of COVID-19: A Retrospectively Studied Analysis of the clinical value of IL-6, ESR，CRP and routine biochemical tests for the diagnosis of COVID-19 Clinical and CT features in pediatric patients with COVID-19 infection: Different points from adults Cardiovascular complications of novel Wuhan Coronavirus (COVID-19) -A 2020 update Analysis of myocardial injury in patients with COVID-19 and association between concomitant cardiovascular diseases and severity of COVID-19 Clinical and biochemical indexes from 2019-nCoV infected patients linked to viral loads and lung injury Association of Cardiac Injury With Mortality in Hospitalized Patients With COVID-19 in Wuhan Myocardial injury is associated with in-hospital mortality of confirmed or suspected COVID-19 in Wuhan Clinical features and outcomes of 2019 novel coronavirus-infected patients with high plasma BNP levels, medRxiv A comparative study on the clinical features of COVID-19 pneumonia to other pneumonias Lactate dehydrogenase, a Risk Factor of Severe Patients: A Retrospective and Observational Study, medRxiv Influence factors of death risk among COVID-19 patients in Analysis of factors associated with disease outcomes in hospitalized patients with 2019 novel coronavirus disease Urinalysis, but not blood biochemistry, detects the early renal-impairment in patients with COVID-19, medRxiv Evaluation of clinical biochemical results in the progression and treatment of COVID-19 Epidemiological and clinical features of COVID-19 patients with and without pneumonia in Highly ACE2 Expression in Pancreas May Cause Pancreas Damage After SARS-CoV-2 Infection medRxiv COVID-19 complicated with DIC: 2 cases report and literatures review Clinical characteristics of 140 patients infected with SARS-CoV-2 in Wuhan Abnormal coagulation parameters are associated with poor prognosis in patients with novel coronavirus pneumonia Hospitalized Patients With 2019 Novel Coronavirus-Infected Pneumonia in D-dimer is Associated with Severity of Coronavirus Disease 2019: A Pooled Analysis Abnormal coagulation parameters are associated with poor prognosis in patients with novel coronavirus pneumonia Neurological Manifestations of Hospitalized Patients with COVID-19 in Wuhan, China: a retrospective case series study medRxiv Diagnostic utility of clinical laboratory data determinations for patients with the severe COVID-19 Reduction and Functional Exhaustion of T Cells in Patients with Coronavirus Disease The definition and risks of Cytokine Release Syndrome-Like in 11 COVID-19-Infected Pneumonia critically ill patients: Disease Characteristics and Retrospective Analysis medRxiv Exuberant elevation of IP-10, MCP-3 and IL-1ra during SARS-CoV-2 infection is associated with disease severity and fatal outcome Immune phenotyping based on neutrophil-to-lymphocyte ratio and IgG predicts disease severity and outcome for patients with COVID-19, medRxiv Prediction of the clinical outcome of COVID-19 patients using T lymphocyte subsets with 340 cases from Wuhan, China: a retrospective cohort study and a web visualization tool, medRxiv Dysregulation of immune response in patients with COVID-19 in Detectable serum SARS-CoV-2 viral load (RNAaemia) is closely correlated with drastically elevated interleukin 6 (IL-6) level in critically ill COVID-19 patients Hospitalized Patients with COVID-19 in Fuyang The diagnostic and predictive role of NLR, d-NLR and PLR in COVID-19 patients The Clinical and Chest CT Features Associated with Severe and Critical COVID-19 Pneumonia Clinical characteristics of refractory COVID-19 pneumonia in Clinical characteristics and outcomes of 112 cardiovascular disease patients infected by 2019-nCoV COVID-19 with Different Severity: A Multi-center Study of Clinical Features COVID-19 in a designated infectious diseases hospital outside Serum Amyloid A is a biomarker of severe Coronavirus Disease and poor prognosis Clinical characteristics of 161 cases of corona virus disease 2019 (COVID-19) in Changsha Temporal profiles of viral load in posterior oropharyngeal saliva samples and serum antibody responses during infection by SARS-CoV-2: an observational cohort study Clinical Characteristics of Coronavirus Disease 2019 in China A Tool to Early Predict Severe Corona Virus Disease 2019 (COVID-19) : A Multicenter Study using the Risk Nomogram in Wuhan and Guangdong Clinical characteristics and outcomes of patients undergoing surgeries during the incubation period of COVID-19 infection Suspected myocardial injury in patients with COVID-19: Evidence from front-line clinical observation in Wuhan, China Neurologic Manifestations of Hospitalized Patients With Coronavirus Disease Decedents with COVID-19 Pneumonia in Wuhan, China Clinical characteristics of non-ICU hospitalized patients with coronavirus disease 2019 and liver injury: A retrospective study Early antiviral treatment contributes to alleviate the severity and improve the prognosis of patients with novel coronavirus disease (COVID-19) Clinical and immunological features of severe and moderate coronavirus disease Clinical features and treatment of COVID-19 patients in northeast Chongqing Epidemiologic and Clinical Characteristics of 91 Hospitalized Patients with COVID-19 in Zhejiang, China: A retrospective, multi-centre case series Evaluation of SARS-CoV-2 RNA shedding in clinical specimens and clinical characteristics of 10 patients with COVID-19 in Macau Conceptualization, Methodology, Software, Investigation, Writing-Original Draft Chenxi Li: Validation, Formal analysis, Visualization, Software Kai Zhang: Validation, Formal analysis, Visualization Haiquan Kang: Resources, Writing -Review & Editing, Supervision, Data Curation Wensen Chen: Resources, Writing -Review & Editing, Supervision, Data Curation Writing: Review & Editing We sorted out the values of laboratory indexes in the collected literature and calculated out the final statistical values We compared the laboratory indexes of severe and non-severe patients infected with COVID-19, which facilitates early diagnosis and treatment of severe and critically ill patients We also described the combined analysis of different types of laboratory indexes, which played an important role in predicting the development of patients' condition