RESEARCH Open Access

Analysis of clinical characteristics andlaboratory findings of 95 cases of 2019novel coronavirus pneumonia in Wuhan,China: a retrospective analysisGemin Zhang1†, Jie Zhang2*†, Bowen Wang1, Xionglin Zhu1, Qiang Wang1 and Shiming Qiu3

Abstract

Background: Since December 2019, 2019 novel coronavirus pneumonia emerged in Wuhan city and rapidly spreadthroughout China and even the world. We sought to analyse the clinical characteristics and laboratory findings ofsome cases with 2019 novel coronavirus pneumonia .

Methods: In this retrospective study, we extracted the data on 95 patients with laboratory-confirmed 2019 novelcoronavirus pneumonia in Wuhan Xinzhou District People’s Hospital from January 16th to February 25th, 2020.Cases were confirmed by real-time RT-PCR and abnormal radiologic findings. Outcomes were followed up untilMarch 2th, 2020.

Results: Higher temperature, blood leukocyte count, neutrophil count, neutrophil percentage, C-reactive proteinlevel, D-dimer level, alanine aminotransferase activity, aspartate aminotransferase activity, α - hydroxybutyratedehydrogenase activity, lactate dehydrogenase activity and creatine kinase activity were related to severe 2019novel coronavirus pneumonia and composite endpoint, and so were lower lymphocyte count, lymphocytepercentage and total protein level. Age below 40 or above 60 years old, male, higher Creatinine level, and lowerplatelet count also seemed related to severe 2019 novel coronavirus pneumonia and composite endpoint, howeverthe P values were greater than 0.05, which mean under the same condition studies of larger samples are needed inthe future.

Conclusion: Multiple factors were related to severe 2019 novel coronavirus pneumonia and composite endpoint,and more related studies are needed in the future.

Keywords: 2019 novel coronavirus, Pneumonia, Clinical characteristics, Laboratory findings

© The Author(s). 2020 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License,which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you giveappropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate ifchanges were made. The images or other third party material in this article are included in the article's Creative Commonslicence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commonslicence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtainpermission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to thedata made available in this article, unless otherwise stated in a credit line to the data.

* Correspondence: 945128911@qq.com†Gemin Zhang and Jie Zhang contributed equally to this work and shouldbe regarded as co-first author.2Department of Neurology, Wuhan Xinzhou District People’s Hospital, 61Xinzhou street, Xinzhou District, Wuhan 430000, Hubei Province, ChinaFull list of author information is available at the end of the article

Zhang et al. Respiratory Research (2020) 21:74 https://doi.org/10.1186/s12931-020-01338-8

BackgroundThe 2019 novel coronavirus pneumonia is caused bya novel betacoronavirus that is currently named 2019novel coronavirus, which was identified by deep se-quencing analysis from lower respiratory tract samples[1, 2]. The 2019 novel coronavirus is the seventhmember of enveloped RNA coronavirus that can in-fect humans [3]. On one hand most human corona-virus infections are mild, on the other hand theinfections of coronavirus including 2019 novel cor-onavirus, severe acute respiratory syndrome corona-virus (SARS-CoV) and Middle East respiratorysyndrome coronavirus (MERS-COV) could be severeor even deadly [3].In early December 2019, the first patient with 2019

novel coronavirus pneumonia emrged in Wuhan city,Hubei province, China [1]. Subsequently the 2019 novelcoronavirus pneumonia rapidly spread throughout china.Soon afterwards many countries declared the first caseof 2019 novel coronavirus pneumonia [4–8]. The 2019novel coronavirus pneumonia emerged in more than151 countries, and the number of laboratory-confirmedcases reached 167,511 and that of the death cases was6606 in the world as of March 16th, 2020 according tothe information from the official website of WorldHealth Organization.In the past 2 months several studies have described

the clinical characteristics of patients with 2019 novelcoronavirus pneumonia [2, 9, 10]. However some casesin these studies had one or more chronic or severeunderlying diseases, which made it difficult to fully as-sess the role of 2019 novel coronavirus in 2019 novelcoronavirus pneumonia without too much interference.Thus we excluded cases with chronic or severe under-lying diseases (i.e., chronic lung disease, chronic heart

disease, chronic liver disease, chronic kidney disease)from our study and analysed the data on 95 patientswith 2019 novel coronavirus pneumonia.

MethodsData sourcesWe performed a retrospective study on the clinical char-acteristics and laboratory findings of laboratory-confirmedcases with 2019 novel coronavirus pneumonia.Inclusion criteria:

1. All cases were diagonosed with pneumonia basedon the clinical manifestations and abnormalfindings of chest X-ray or computed tomography.

2. A confirmed case with 2019 novel coronaviruspneumonia was defined as a positive result to high-throughput sequencing or real-time reverse-transcriptase polymerase-chain-reaction assay fornasal and pharyngeal swab specimens [1].

Exclusion criteria:

1. patients with Common bacteria or virusesassociated with community-acquired pneumonia.

2. Patients with chronic or severe underlying diseases.3. Procalcitonin level > 0.5 ng/ml.

A flow chart, from the total number of patients up tothe 95 patients of the study, was shown by Fig. 1. About14.2% (18/127) of the patients had one or more chronicor severe underlying diseases, and about 9.4% (12/127)of the patients were co-infected with 2019 novel corona-virus and other respiratory pathogens (i.e., Chlamydiapneumoniae, Mycoplasma pneumoniae, adenovirus, andrespiratory syncytial virus).

Fig. 1 A flow chart, from the total number of patients up to the 95 patients of the study. About 14.2% (18/127) of the patients had one or morechronic or severe underlying diseases, and about 9.4% (12/127) of the patients were co-infected with 2019 novel coronavirus and otherrespiratory pathogens (i.e., Chlamydia pneumoniae, Mycoplasma pneumoniae, adenovirus and respiratory syncytial virus)

Zhang et al. Respiratory Research (2020) 21:74 Page 2 of 10

All data including age, sex, temperature and laboratoryfindings were extracted from electronic medical records.Laboratory assessments consisted of complete bloodcount, blood chemistry, coagulation test, liver and renalfunction, serum total protein, C-reactive protein, α-hydroxybutyrate dehydrogenase, lactate dehydrogenaseand creatine kinase. The severity of 2019 novel corona-virus pneumonia was defined accroding to the fifth edi-tion diagnosis and treatment program of 2019 novelcoronavirus pneumonia issued by the National HealthCommission of the People’s Republic of China. Finally,63 non-severe cases and 32 severe cases were includedinto our study.

Definition of severe 2019 novel coronavirus pneumoniaRespiration rate ≥ 30 times / min; at rest, oxygen satur-ation ≤ 93%; arterial partial pressure of oxygen(PaO2) /fraction of inspired oxygen(FiO2) ≤ 300mmHg.

Definition of composite endpointThe composite endpoint was the admission to intensivecare unit (ICU), or mechanical ventilation, or death.

Laboratory testPatients usually received lab test every 2 days or whenchanging in health condition.

Statistical analysisContinuous variables were expressed as the medians andinterquartile ranges (IQR). Categorical variables weresummarized as the counts and percentages in each cat-egory. We grouped patients into severe and non-severecases according to the fifth edition diagnosis and treat-ment program of 2019 novel coronavirus pneumonia is-sued by the National Health Commission of the People’sRepublic of China. Wilcoxon rank-sum tests were ap-plied to continuous variables, chi-square tests and Fish-er’s exact tests were used for categorical variables asappropriate, Kendall rank correlation coefficient (repre-sented by R) was adopted to measure the degree of rankcorrelation between the fitness and each variable. Allanalyses were conducted with SPSS software version23.0 (Statistical Product and Service Solutions). Differ-ences with P values < 0.05 were considered significant.

ResultsDemographic and clinical characteristicsThe demographic and clinical characteristics are shownin Table 1.

AgeAt first, we grouped patients into three groups (<40years group, 40–60 years group, and >60 years group) ac-cording to their age as shown by Table 1.

Of all the 95 patients, the youngest one was 23 yearsold, the oldest one was 88 years old. The median agewas 49.0 years (IQR, 39.0 to 58.0). 24 (25.3%) patientswere aged below 40 years. 54 (56.8) patients were agedbetween 40 and 60 years old. 17 (17.9) patients wereaged above 60 years old.For<40 years group, 41.7% of the patients were severe

cases and 33.3% of the patients reached the compositeendpoint. For 40–60 years group, 27.8% of the patientswere severe cases and 18.5% of the patients reached thecomposite endpoint. For >60 years group, 41.2% of thepatients were severe cases and 41.2% of the patientsreached the composite endpoint. We can see that pa-tients aged between 40 and 60 years had lower risk ofbeing severe cases or reaching the composite endpointwhen compared with other groups. However, the Pvalues were greater than 0.05. (P1 = 0.376, P2 = 0.120).We further regrouped patients into two groups (<40

years or >60 years group, and 40–60 years group) in viewof above results. As shown by Table 1, <40 years or >60years group was related to higher risk of reaching thecomposite endpoint (R2 = 0.203, P4 = 0.049).

GenderAs shown by Table 1, 44.2% of patients were female, and55.8% of patients were male.For female group, 26.2% of the the patients were se-

vere cases, and 21.4% of the patients reached the com-posite endpoint. For male group, 39.6% of the patientswere severe cases, and 30.2% of the patients reached theendpoint. However, the P values were greater than 0.05.(P1 = 0.195, P2 = 0.360, P3 = 0.171, P4 = 0.338).

TemperatureAs shown by Table 1, we grouped patients into fourgroups according to their highest temperature duringhospitalization.For <37 °C group, 12.5% of the patients were severe

cases, and no patients reached the composite endpoint.For 37–38 °C group, 10.5% of the the patients were se-vere cases, and 10.5% of the patients reached the com-posite endpoint. For 38–39 °C group, 28.6% of the thepatients were severe cases, and 17.1% of the patientsreached the composite endpoint. For >39 °C, 57.6% ofthe the patients were severe cases, and 51.5% of thepatients reached the composite endpoint. (P1 = 0.002,P2 = 0.001).Higher temperature was related to severe 2019

novel coronavirus pneumonia and composite endpoint.(R1 = 0.362, R2 = 0.383, P3<0.001, P4<0.001).

Laboratory findingsThe Laboratory findings are shown in Table 2.

Zhang et al. Respiratory Research (2020) 21:74 Page 3 of 10

Table

1Clinicalcharacteristicsof

95patientswith

2019

novelcoron

aviru

spn

eumon

ia

Clinicalcharacteristics

Allpatients(n

=95)

Disease

severity

Com

posite

endp

oint

No-severe

(n=63)

Severe

(n=32)

P1R1

P3No(n

=70)

Yes(n

=25)

P2R2

P4

Age,

Med

ian(ran

ge)-yea

rs49.0(39.0–58.0)

49.0(41.0–57.0)

50.5(38.3–58.8)

0.79

10.02

30.78

949.0(40.8–56.3)

52.0(37.5–63.0)

0.41

30.07

00.41

0

Agegroup

s-No.,%

0.37

6−0.02

60.79

40.12

00.02

20.82

0

<40

years(n=24)

24/95(25.3)

14/63(22.2)

10/32(31.3)

16/70(22.9)

8/25

(32.0)

14/24(58.3)

10/24(41.7)

16/24(66.7)

8/24

(33.3)

40–60years(n=54)

54/95(56.8)

39/63(61.9)

15/32(46.9)

44/70(62.9)

10/25(40.0)

39/54(72.2)

15/54(27.8)

44/52(81.5)

10/52(18.5)

>60

years(n=17)

17/95(17.9)

10/63(15.9)

7/32

(21.9)

10/70(14.3)

7/25

(28.0)

10/17(58.8)

7/17

(41.2)

10/17(58.8)

7/17

(41.2)

Agegroup

s-No.,%

0.19

20.14

30.16

40.06

10.20

30.04

9

40–60years(n=54)

54/95(56.8)

39/63(61.9)

15/32(46.9)

44/70(62.9)

10/25(40.0)

39/54(72.2)

15/54(27.8)

44/54(81.5)

10/54(18.5)

<40

yearsor

>60

years(n=41)

41/95(43.2)

24/63(38.1)

17/32(53.1)

26/70(37.1)

15/25(60.0)

24/41(58.5)

17/41(41.5)

26/41(63.4)

15/41(36.6)

Sex-No.,%

0.19

50.14

20.17

10.36

00.09

90.33

8

Female(n=42)

42/95(44.2)

31/63(49.2)

11/32(34.4)

33/70(44.2)

9/25

(36.0)

31/42(73.8)

11/42(26.2)

33/42(78.6)

9/42

(21.4)

Male(n=53)

53/95(55.8)

32/63(50.8)

21/32(65.6)

37/70(55.8)

16/25(64.0)

32/53(60.4)

21/53(39.6)

37/53(69.8)

16/53(30.2)

Highe

sttemperatureduringho

spitalization-No.,%

0.00

20.36

2<0.00

10.00

10.38

3<0.00

1

<37

°C(n=8)

8/95

(8.4)

7/63

(11.1)

1/32

(3.1)

8/70

(11.4)

0/25

(0.0)

7/8(87.5)

1/8(12.5)

8/8(100.0)

0/8(0.0)

37–38°C

(n=19)

19/95(20.0)

17/63(27.0)

2/32

(6.3)

17/70(24.3)

2/25

(8.0)

17/19(89.5)

2/19

(10.5)

17/19(89.5)

2/19

(10.5)

38–39°C

(n=35)

35/95(36.8)

25/63(39.7)

10/32(31.3)

29/70(41.4)

6/25

(24.0)

25/35(71.4)

10/35(28.6)

29/35(82.9)

6/35

(17.1)

>39

°C(n=33)

33/95(34.7)

14/63(22.2)

19/32(59.4)

16/70(22.9)

17/25(68.0)

14/33(42.4)

19/33(57.6)

16/33(48.5)

17/33(51.5)

Pvalues

deno

tedthecompa

rison

betw

eenno

n-severe

casesan

dsevere

cases

Kend

allran

kcorrelationcoefficient

(rep

resented

byR)

was

adop

tedto

measure

thede

gree

ofrank

correlationbe

tweenthefitne

ssan

deach

varia

ble

Zhang et al. Respiratory Research (2020) 21:74 Page 4 of 10

Blood leukocyte count

Highest blood leukocyte count As shown by Table 2,we first grouped patients into two groups according totheir highest blood leukocyte count duringhospitalization. The ≤10 * 10^9/L group were further di-vided into two subgroups according to their lowestblood leukocyte count during hospitalization.For > 10*10^9/L group, 96.0% of the patients were se-

vere cases, and 80.0% of the patients reached the com-posite endpoint. For 4–10 * 10^9/L group, 11.4% of thepatients were severe cases, and 5.7% of the patientsreached the composite endpoint. For < 4 * 10^9/L group,11.4% of the patients were severe cases, and 8.6% of thepatients reached the composite endpoint. (P1<0.001,P2<0.001).> 10*10^9/L group were strongly related to severe

2019 novel coronavirus pneumonia and composite end-point. (R1 = 0.604, P3<0.001, R2 = 0.543, P4<0.001).

Lowest blood leukocyte count As shown by Table 2,we first grouped patients into two groups according totheir lowest blood leukocyte count duringhospitalization. The ≥4 * 10^9/L group were further di-vided into two subgroups according to their highestblood leukocyte count during hospitalization.For<4 * 10^9/L group, 16.2% of the patients were se-

vere cases, and 8.1% of the patients reached the compos-ite endpoint. For 4–10 * 10^9/L group, 11.4% of thepatients were severe cases, and 5.7% of the patientsreached the composite endpoint. For > 10*10^9/L group,95.7% of the patients were severe cases, and 87.0% of thepatients reached the composite endpoint. (P1<0.001, P2<0.001).> 10*10^9/L group were strongly related to severe

2019 novel coronavirus pneumonia and composite end-point. (R1 = 0.604, P3<0.001, R2 = 0.569, P4<0.001).

Neutrophils

Highest neutrophil count As shown by Table 2, wefirst grouped patients into two groups according totheir highest neutrophil count during hospitalization.The ≤7 * 10^9/L group were further divided into twosubgroups according to their lowest neutrophil countduring hospitalization.For > 7*10^9/L group, 86.7% of the patients were

severe cases, and 73.2% of the patients reached thecomposite endpoint. For 2–7 * 10^9/L group, 9.5% ofthe patients were severe cases, and 2.4% of the pa-tients reached the composite endpoint. For < 2 *10^9/L group, 8.7% of the patients were severe cases,and 8.7% of the patients reached the composite end-point. (P1<0.001, P2<0.001).

Table 2 Laboratory findings of 95 patients with 2019 novelcoronavirus pneumonia

Zhang et al. Respiratory Research (2020) 21:74 Page 5 of 10

> 7*10^9/L group were strongly related to severe 2019novel coronavirus pneumonia and composite endpoint.(R1 = 0.626, P3<0.001, R2 = 0.566, P4<0.001).

Highest neutrophil percentage As shown by Table 2,we grouped patients into three groups according to theirhighest neutrophil percentage during hospitalization.For > 85% group, 83.9% of the patients were severe

cases, and 61.3% of the patients reached thecomposite endpoint. For 70–85% group, 13.2% of thepatients were severe cases, and 13.2% of the patientsreached the composite endpoint. For ≤70% group,3.8% of the patients were severe cases, and 3.8% ofthe patients reached the composite endpoint. (P1<0.001,P2<0.001).Higher neutrophil percentage was strongly related

to severe 2019 novel coronavirus pneumonia andcomposite endpoint. (R1 = 0.641, P3<0.001, R2 = 0.492,P4<0.001).

Lymphocyte

Lowest lymphocyte count As shown by Table 2, wegrouped patients into three groups according to theirLowest lymphocyte count during hospitalization.For<0.4* 10^9/L group, 81.8% of the patients were se-

vere cases, and 81.8% of the patients reached the com-posite endpoint. For 0.4–0.8* 10^9/L group, 42.9% of thepatients were severe cases, and 28.6% of the patientsreached the composite endpoint. For >0.8* 10^9/Lgroup, 11.9% of the patients were severe cases, and 9.5%of the patients reached the composite endpoint. (P1<0.001, P2<0.001).Lower lymphocyte count was strongly related to

severe 2019 novel coronavirus pneumonia and com-posite endpoint. (R1 = -0.451, P3<0.001, R2 = -0.415,P4<0.001).

Lowest lymphocyte percentage As shown by Table 2,we grouped patients into three groups according to theirLowest lymphocyte percentage during hospitalization.For<10% group, 81.3% of the patients were severe

cases, and 68.8% of the patients reached the compositeendpoint. For 10–20% group, 14.3% of the patients weresevere cases, and 5.7% of the patients reached the com-posite endpoint. For>20% group, 3.6% of the patientswere severe cases, and 3.6% of the patients reached thecomposite endpoint. (P1<0.001, P2<0.001).Lower lymphocyte percentage was strongly related to

severe 2019 novel coronavirus pneumonia and com-posite endpoint. (R1 = − 0.631, P3<0.001, R2 = − 0.573,P4<0.001).

C-reactive protein levelAs shown by Table 2, we grouped patients into fivegroups according to their highest C-reactive proteinlevel during hospitalization.For<10 mg/L and 10–20mg/L groups, no patients

were severe cases, and no patients reached the compos-ite endpoint. For 20–90mg/L group, 18.7% of the pa-tients were severe cases, and 12.5% of the patientsreached the composite endpoint. For 90–150 mg/Lgroup, 31.2% of the patients were severe cases, and25.0% of the patients reached the composite endpoint.For>150mg/L group, 84.0% of the patients were severecases, and 68.0% of the patients reached the compositeendpoint. (P1<0.001, P2<0.001).Higher C-reactive protein level was strongly related

to severe 2019 novel coronavirus pneumonia andcomposite endpoint. (R1 = 0.572, P3<0.001, R2 = 0.503,P4<0.001).

Platelet countAs shown by Table 2, we grouped patients into threegroups according to their Platelet count duringhospitalization.For<100* 10^9/L groups, 45.5% of patients were se-

vere cases, and 45.5% patients reached the compositeendpoint. For 100–300* 10^9/L group, 26.8% of thepatients were severe cases, and 24.4% of the patientsreached the composite endpoint. For >300* 10^9/Lgroup, 37.2% of the patients were severe cases, and23.3% of the patients reached the composite endpoint.However, the P values were greater than 0.05. (P1 =0.410, P2 = 0.307, P3 = 0.795, P4 = 0.306).

Highest D-dimer levelAs shown by Table 2, we grouped patients into twogroups according to their highest D-dimer level duringhospitalization.For ≤1mg/L group, 9.5% of patients were severe cases,

and 3.2% patients reached the composite endpoint.For>1 mg/L group, 81.2% of the patients were severecases, and 71.9% of the patients reached the compositeendpoint. (P1<0.001, P2<0.001).Higher D-dimer level was strongly related to severe

2019 novel coronavirus pneumonia and composite end-point. (R1 = 0.717, P3<0.001,R2 = 0.737,P4<0.001).

Highest alanine aminotransferase activityAs shown by Table 2, we grouped patients into threegroups according to their highest alanine aminotransfer-ase activity during hospitalization.For<40 U/L group, 18.6% of patients were severe cases,

and 9.3% patients reached the composite endpoint. For40–80 U/L group, 48.1% of the patients were severecases, and 40.7% of the patients reached the composite

Zhang et al. Respiratory Research (2020) 21:74 Page 6 of 10

endpoint. For>80 U/L group, 44.0% of the patients weresevere cases, and 40.0% of the patients reached the com-posite endpoint. (P1 = 0.017, P2 = 0.003).Higher alanine aminotransferase activity was related to

severe 2019 novel coronavirus pneumonia and compos-ite endpoint. (R1 = 0.243, P3 = 0.013, R2 = 0.306, P4 =0.002).

Highest aspartate aminotransferase activityAs shown by Table 2, we grouped patients into threegroups according to their highest aspartate aminotrans-ferase activity during hospitalization.For<40 U/L group, 24% of patients were severe cases,

and 12% patients reached the composite endpoint. For40–80 U/L group, 44.1% of the patients were severecases, and 41.2% of the patients reached the compositeendpoint. For>80 U/L group, 45.5% of the patients weresevere cases, and 45.5% of the patients reached the com-posite endpoint. (P1 = 0.109, P2 = 0.004).Higher aspartate aminotransferase activity was related

to severe 2019 novel coronavirus pneumonia and com-posite endpoint. (R1 = 0.202, P3 = 0.042, R2 = 0.325, P4 =0.001).

Highest Creatinine levelAs shown by Table 2, we grouped patients into twogroups according to their highest Creatinine level duringhospitalization.For≤90 μmol/L group, 32.9% of the patients were se-

vere cases, and 24.7% of the patients reached the com-posite endpoint. For>90 μmol/L group, 36.4% of thepatients were severe cases, and 31.8% of the patientsreached the composite endpoint. However, the P valueswere greater than 0.05. (P1 = 0.800, P2 = 0.583, P3 =0.763, P4 = 0.506).

Highest α - hydroxybutyrate dehydrogenase activityAs shown by Table 2, we grouped patients into fourgroups according to their highest α - hydroxybutyratedehydrogenase activity during hospitalization.For<183 U/L group, no patients were severe cases, and

no patients reached the composite endpoint. For 183–360 U/L group, 20.0% of the patients were severe cases,and 14.0% of the patients reached the composite end-point. For 360–540 U/L group, 46.4% of the patientswere severe cases, and 32.1% of the patients reached thecomposite endpoint. For>540 U/L group, 90.0% ofpatients were severe cases, and 90.0% patients reachedthe composite endpoint. (P1<0.001, P2<0.001).Higher α - hydroxybutyrate dehydrogenase activity

correlated strongly with severe 2019 novel corona-virus pneumonia and composite endpoint. (R1 = 0.449,P3<0.001, R2 = 0.439, P4<0.001).

Highest lactate dehydrogenase activityAs shown by Table 2, we grouped patients into fourgroups according to their highest lactate dehydrogenaseactivity during hospitalization.For<245 U/L group, 4.8% of the patients were severe

cases, and none of the patients reached the compositeendpoint. For 245–480 U/L group, 30.9% of the patientswere severe cases, and 23.6% of the patients reached thecomposite endpoint. For 480–720 U/L group, 61.5% ofthe patients were severe cases, and 46.2% of the patientsreached the composite endpoint. For>720 U/L group, allthe patients were severe cases, and all the patientsreached the composite endpoint. (P1<0.001, P2<0.001).Higher lactate dehydrogenase activity correlated

strongly with severe 2019 novel coronavirus pneumoniaand composite endpoint. (R1 = 0.454, P3<0.001, R2 =0.453, P4<0.001).

Highest creatine kinase activityAs shown by Table 2, we grouped patients into fourgroups according to their highest creatine kinase activityduring hospitalization.For<200 U/L group, 26.9% of the patients were severe

cases, and 17.9% of the patients reached the compositeendpoint. For 200-400 U/L group, 41.7% of the patientswere severe cases, and 41.7% of the patients reached thecomposite endpoint. For 400-600 U/L group, 44.4% ofthe patients were severe cases, and 44.4% of the patientsreached the composite endpoint. For>600 U/L group,71.4% of the patients were severe cases, and 57.1% of thepatients reached the composite endpoint. (P1 = 0.083,P2 = 0.031).Higher creatine kinase activity correlated strongly with

severe 2019 novel coronavirus pneumonia and compositeendpoint. (R1 = 0.231, P3 = 0.019, R2 = 0.289, P4 = 0.003).

Lowest total protein levelAs shown by Table 2, we grouped patients into twogroups according to their Lowest total protein level dur-ing hospitalization.For<60 g/L group, 44.6% of the patients were severe

cases, and 33.8% of patients reached the composite end-point. For ≥60 g/L group, 10.0% of the patients were se-vere cases, and 10.0% of the patients reached thecomposite endpoint. (P1 = 0.001, P2 = 0.022).Lower total protein level correlated with severe 2019

novel coronavirus pneumonia and composite endpoint.(R1 = − 0.340, P3 = 0.001, R2 = − 0.252, P4 = 0.015).

DiscussionAccording to the results of our study, higher temperature,blood leukocyte count, neutrophil count, neutrophil per-centage, C-reactive protein level, D-dimer level, alanineaminotransferase activity, aspartate aminotransferase

Zhang et al. Respiratory Research (2020) 21:74 Page 7 of 10

activity, α - hydroxybutyrate dehydrogenase activity, lac-tate dehydrogenase activity and creatine kinase activitywere related to severe 2019 novel coronavirus pneumoniaand composite endpoint, and so were lower lymphocytecount, lymphocyte percentage and total protein level. Agebelow 40 or above 60 years old, male, higher Creatininelevel, and lower platelet count also seemed related to se-vere 2019 novel coronavirus pneumonia and compositeendpoint, however the P values were greater than 0.05,which mean under the same condition studies of largersamples are needed in the future.Different from the results of previous studies [2, 9, 10],

our study indicated that severe 2019 novel coronaviruspneumonia and composite endpoint had more to dowith leukocytosis rather than leukopenia. This differenceis mainly because of the different inclusion criteria andevaluation index we used. The leukocytosis was unlikelyto be caused by bacterial infection because we excludedcommon bacteria or viruses associated with community-acquired pneumonia and procalcitonin level of all pa-tients in our study was no greater than 0.5 ng/ml. Wethink that the leukocytosis was a reflection of excessiveinflammation. The excessive inflammation was alsoreflected by the much higher C-reactive protein level ofpatients with severe 2019 novel coronavirus pneumoniaas shown by Table 2.In our study, the leukocytosis was always accompanied

by an increase in neutrophil count and neutrophil per-centage. That makes sense because the overwhelmingmajority of blood leukocyte was neutrophils, and thehighest percentage of neutrophils was 97.5% in ourstudy. As described above, neutrophilia was related tosevere 2019 novel coronavirus pneumonia and compos-ite endpoint. However, Up to now most of the researchhave focused on the role of lymphocyte in 2019 novelcoronavirus pneumonia. We think that the role of neu-trophils in 2019 novel novel coronavirus pneumoniashouldn’t be ignored and further related researches areneeded in the future.The leukocytosis was also accompanied by a decrease

in lymphocyte count and lymphocyte percentage. Itshould be noted that leukocytosis was not incompatiblewith lymphopenia, and lymphopenia could occur bothwhen blood leukocyte count incarease and decrease.Consistent with previous studies [11], lymphopenia wasmore severe and common in patients with severe 2019novel coronavirus pneumonia. As suggested, the lym-phopenia was probably caused by the translocation oflymphocyte from peripheral blood to lungs [11].We also evaluated the Coagulation, liver and renal func-

tion of patients with 2019 novel coronavirus pneumonia.In light of our observation, D-dimer was the most

common abnormal coagulation index. As describedabove, higher D-dimer level was strongly related to

severe 2019 novel coronavirus pneumonia and compos-ite endpoint (R1 = 0.717, P1<0.001, R2 = 0.737, P<0.001).The increased D-dimer level reflected a hypercoagulablestate, which might promote pulmonary microthrombo-sis. This hypothesis need to be further confirmed.Alanine aminotransferase activity and aspartate amino-

transferase activity were used to evaluate liver functionin our study. As shown by Table 2, about half of the pa-tients were found liver fuction injury, and liver fuctioninjury was related to severe 2019 novel coronaviruspneumonia and composite endpoint. However we didn’tsee an obvious difference between 40 and 80 U/L groupand >80 U/L group, and most of the liver fucntion weretemporary and reversible. That means the liver functioninjury might be caused by multiple factors: immunity,inflammation and drugs.Creatinine level was used to evaluate renal function in

our study. A recent research indicated that the 2019novel coronavirus was found in patients’ urine [12].However, we didn’t see an obvious difference in creatin-ine level between severe group and non-severe group.Therefore, the influence of 2019 novel coronavirus onrenal function need to be further studied though the2019 novel coronavirus was found in patients’ urine.Besides, higherα- hydroxybutyrate dehydrogenase ac-

tivity, lactate dehydrogenase activity and creatine kinaseactivity were related to severe cases and reach of com-posite endpoint. In our study, 92.6% of the patients hadan increase in α- hydroxybutyrate dehydrogenase activ-ity, 77.9% of the patients had an increase in lactate de-hydrogenase activity, and 29.5% of the patients had anincrease in creatine kinase activity. α- hydroxybutyratedehydrogenase activity, lactate dehydrogenase activityand creatine kinase activity were usually used to evaluethe degree of myocardial injury. However, we had nodirect radiological or histopathological evidence to provethat myocardial injury really happened. Thus the influ-ence of 2019 novel coronavirus on heart also need to befurther studied.In addition we used the total protein level to evaluate

the nutritional condition of patients with 2019 novelcoronavirus pneumonia. According to our study, about68.4% of the patients had a decrease in total proteinlevel. Lower total protein level correlated with severe2019 novel coronavirus pneumonia and composite end-point. The decrease in total protein level reflected a highconsumption state of nutrition, which suggested thatpatients with 2019 novel coronavirus pneumonia neededmore nutrition during hospitalization.Moreover, we compared the clinical characteristics

and laboratory findings between death group and sur-vival group as shown by Supplementary Table 1 andSupplementary Table 2. Age above 60 years old, male,blood leukocyte count > 10*10^9/L, neutrophil count >

Zhang et al. Respiratory Research (2020) 21:74 Page 8 of 10

7*10^9/L, neutrophil percentage > 85%, lymphocytecount <0.4* 10^9/L, lymphocyte percentage<10%, C-reactive protein level >150 mg/L, D-dimer level >1 mg/L,α - hydroxybutyrate dehydrogenase activity>540 U/L andlactate dehydrogenase activity>720 U/L were obviouslyrelated to a consequence of death.In some degree, our research was different from

pevious similiar studies [2, 9, 10]. Firstly we adopted adifferent inclusion criteria:patients with chronic orsevere underlying diseases were excluded as describedabove. Secondly we applied different evaluation index:when assessing the relationship between candidates withthe severity of 2019 novel coronavirus pneumonia, weused the highest or lowest level of candidates duringhospitalization while the previous studies mainly usedthe fixed value of candidates on admission. We adopteddifferent inclusion criteria and evaluation index for thefollowing reasons: Firstly, chronic or severe underlyingdiseases could make it difficult to fully assess the role of2019 novel coronavirus in 2019 novel coronavirus pneu-monia without too much interference. Secondly, thelaboratory findings of patients on admission could beunrepresentative because laboratory findings may varydepending on patient’s condition, and many cases thatreached composite endpoint during hospitalization couldbe non-severe cases on admission.However, there were also some limitaions of our study.

The main limitations included the reseach type (Singlecenter retrospective study) and a lack of cases. And itwas not credible to conduct a multivariate analysisbecause of the lack of cases in our study.Above are the main points of our study.

ConclusionOur study was different from pevious similiar studies be-cause of the different inclusion criteria and evaluationindex we applied, which offered another perspective onthe relationship between various factors and 2019 novelcoronavirus pneumonia.Different from previous study we found that severe

2019 novel coronavirus pneumonia and composite end-point had more to do with leukocytosis rather thanleukopenia. Leukocytosis was always accompanied by anincrease in neutrophil count and neutrophil percentage.The role of neutrophils in 2019 novel coronavirus pneu-monia shouldn’t be ignored and further related re-searches are needed in the future. Consistent withprevious studies, lymphopenia was found more severeand common in patients with severe 2019 novel corona-virus pneumonia. The lymphopenia was probably causedby the translocation of lymphocyte from peripheralblood to lungs [11].Besides higher D-dimer level and impaired liver func-

tion were related to severe 2019 novel coronavirus

pneumonia and composite endpoint. The increased D-dimer level reflected a hypercoagulable state, whichmight promote pulmonary microthrombosis. This hy-pothesis need to be further confirmed. Most of the liverfucntion were temporary and reversible, and the liverfunction injury might be caused by multiple factors: im-munity, inflammation and drugs. However, we didn’t seean obvious difference in creatinine level between severegroup and non-severe group.In addition, higherα- hydroxybutyrate dehydrogenase

activity, lactate dehydrogenase activity and creatine kin-ase activity were related to severe cases and reach ofcomposite endpoint. The influence of 2019 novel cor-onavirus on heart also need to be further studied.Furthermore the decrease in total protein level

reflected a high consumption state of nutrition, whichsuggested that patients with 2019 novel coronaviruspneumonia need more nutrition during hospitalization.In summary, multiple factors were found related to

the severity of 2019 novel coronavirus pneumonia andcomposite endpoint. More related studies are needed inthe future.

Supplementary informationSupplementary information accompanies this paper at https://doi.org/10.1186/s12931-020-01338-8.

Additional file 1 : Supplementary Table 1. Clinical characteristics of95 patients with 2019 novel coronavirus pneumonia. SupplementaryTable 2. Laboratory findings of 95 patients with 2019 novel coronaviruspneumonia.

AbbreviationsSARS-CoV: Severe acute respiratory syndrome coronavirus; MERS-COV: MiddleEast respiratory syndrome coronavirus; ICU: Intensive care unit;IQR: Interquartile ranges; SPSS: Statistical product and service solutions

AcknowledgementsNot applicable.

Authors’ contributionsGZ and JZ designed the study and undertook most of the work, they shouldbe regarded as co-first author. BW, XZ, QW and SQ participated in data col-lection and analysis. All authors have contributed to the last version of themanuscript. The authors read and approved the final manuscript.

FundingThis study was not funded by anyone.

Availability of data and materialsAll data generated or analysed during this study are included in thispublished article [and its supplementary information files].

Ethics approval and consent to participateEthics Committee of Xinzhou District People’s Hospital approved this study.

Consent for publicationNot applicable.

Competing interestsThe authors declare that they have no competing interests.

Zhang et al. Respiratory Research (2020) 21:74 Page 9 of 10

Author details1Department of infectious disease, Wuhan Xinzhou District People’s Hospital,Wuhan, China. 2Department of Neurology, Wuhan Xinzhou District People’sHospital, 61 Xinzhou street, Xinzhou District, Wuhan 430000, Hubei Province,China. 3Department of critical care medicine, Wuhan Xinzhou DistrictPeople’s Hospital, Wuhan, China.

Received: 7 March 2020 Accepted: 18 March 2020

References1. Lu R, Zhao X, Li J, Niu P, Yang B, Wu H, Wang W, Song H, Huang B, Zhu N,

et al. Genomic characterisation and epidemiology of 2019 novelcoronavirus: implications for virus origins and receptor binding. Lancet.2020;395(10224):565–74.

2. Huang C, Wang Y, Li X, Ren L, Zhao J, Hu Y, Zhang L, Fan G, Xu J, Gu X,et al. Clinical features of patients infected with 2019 novel coronavirus inWuhan, China. Lancet. 2020;395(10223):497–506.

3. Zhu N, Zhang D, Wang W, Li X, Yang B, Song J, Zhao X, Huang B, Shi W, LuR, et al. A novel coronavirus from patients with pneumonia in China, 2019.N Engl J Med. 2020;382(8):727–33.

4. Phan LT, Nguyen TV, Luong QC, Nguyen TV, Nguyen HT, Le HQ, Nguyen TT,Cao TM, Pham QD. Importation and human-to-human transmission of anovel coronavirus in Vietnam. N Engl J Med. 2020;382(9):872–4.

5. Rothe C, Schunk M, Sothmann P, Bretzel G, Froeschl G, Wallrauch C, ZimmerT, Thiel V, Janke C, Guggemos W, et al. Transmission of 2019-nCoV infectionfrom an asymptomatic contact in Germany. N Engl J Med. 2020;382(10):970–1.

6. Holshue ML, DeBolt C, Lindquist S, Lofy KH, Wiesman J, Bruce H, Spitters C,Ericson K, Wilkerson S, Tural A, et al. First case of 2019 novel coronavirus inthe United States. N Engl J Med. 2020;382(10):929–36.

7. Arashiro T, Furukawa K, Nakamura A. COVID-19 in 2 Persons with MildUpper Respiratory Symptoms on a Cruise Ship, Japan. Emerg Infect Dis.2020;26(6). PMID: 32118533. https://doi.org/10.3201/eid2606.200452.

8. Park WB, Kwon NJ, Choi SJ, Kang CK, Choe PG, Kim JY, Yun J, Lee GW,Seong MW, Kim NJ, et al. Virus isolation from the first patient with SARS-CoV-2 in Korea. J Korean Med Sci. 2020;35(7):e84.

9. Chen N, Zhou M, Dong X, Qu J, Gong F, Han Y, Qiu Y, Wang J, Liu Y, Wei Y,et al. Epidemiological and clinical characteristics of 99 cases of 2019 novelcoronavirus pneumonia in Wuhan, China: a descriptive study. LANCET. 2020;395(10223):507–13.

10. Guan WJ, Ni ZY, Hu Y, Liang WH, Ou CQ, He JX, Liu L, Shan H, Lei CL, Hui D,et al. Clinical characteristics of coronavirus disease 2019 in China. N Engl JMed. 2020. PMID: 32109013. https://doi.org/10.1056/NEJMoa2002032.

11. Xu Z, Shi L, Wang Y, Zhang J, Huang L, Zhang C, Liu S, Zhao P, Liu H, Zhu L,et al. Pathological findings of COVID-19 associated with acute respiratorydistress syndrome. Lancet Respir Med. 2020. PMID: 32085846. https://doi.org/10.1016/S2213-2600(20)30076-X.

12. Ling Y, Xu SB, Lin YX, Tian D, Zhu ZQ, Dai FH, Wu F, Song ZG, Huang W,Chen J, et al. Persistence and clearance of viral RNA in 2019 novelcoronavirus disease rehabilitation patients. Chin Med J. 2020. PMID:32118639. https://doi.org/10.1097/CM9.0000000000000774.

Publisher’s NoteSpringer Nature remains neutral with regard to jurisdictional claims inpublished maps and institutional affiliations.

Zhang et al. Respiratory Research (2020) 21:74 Page 10 of 10