Elsevier

Clinica Chimica Acta

Volume 519, August 2021, Pages 172-182
Clinica Chimica Acta

Review
Clinical laboratory evaluation of COVID-19

https://doi.org/10.1016/j.cca.2021.04.022Get rights and content

Highlights

  • Nucleic acid tests can serve as the pathogenic evidence for the diagnosis of COVID-19.

  • Specific antibodies of SARS-CoV-2 (IgG, IgM, and IgA) are the effective complement for false-negative detection of SARS-CoV-2 nucleic acid in clinically suspected cases.

  • Antigen tests to identify SARS-CoV-2 infection are recommended in the early stages with high viral loads.

  • Dynamic detection of some biomarkers such as lymphocytes, LDH, AST, D-dimer, CRP, SAA, and IL-6 will be helpful as an early warning of serious diseases, especially in high-risk patients of severe and critical illness.

Abstract

COVID-19, caused by SARS-CoV-2, is a highly infectious disease, and clinical laboratory detection has played important roles in its diagnosis and in evaluating progression of the disease. Nucleic acid amplification testing or gene sequencing can serve as pathogenic evidence of COVID-19 diagnosing for clinically suspected cases, and dynamic monitoring of specific antibodies (IgM, IgA, and IgG) is an effective complement for false-negative detection of SARS-CoV-2 nucleic acid. Antigen tests to identify SARS-CoV-2 are recommended in the first week of infection, which is associated with high viral loads. Additionally, many clinical laboratory indicators are abnormal as the disease evolves. For example, from moderate to severe and critical cases, leukocytes, neutrophils, and the neutrophil–lymphocyte ratio increase; conversely, lymphocytes decrease progressively but are over activated. LDH, AST, ALT, CK, high-sensitivity troponin I, and urea also increase progressively, and increased D-dimer is an indicator of severe disease and an independent risk factor for death. Severe infection leads to aggravation of inflammation. Inflammatory biomarkers and cytokines, such as CRP, SAA, ferritin, IL-6, and TNF-α, increase gradually. High-risk COVID-19 patients with severe disease, such as the elderly and those with underlying diseases (cardiovascular disease, diabetes, chronic respiratory disease, hypertension, obesity, and cancer), should be monitored dynamically, which will be helpful as an early warning of serious diseases.

Keywords

SARS-CoV-2
COVID-19
Laboratory diagnosis
Biomarker

Abbreviations

COVID-19
coronavirus disease 2019
SARS-CoV
severe acute respiratory syndrome coronavirus
SARS-CoV-2
severe acute respiratory syndrome coronavirus 2
MERS-CoV
middle east respiratory syndrome coronavirus
ACE
angiotensin-converting enzyme
ACE2
angiotensin-converting enzyme 2
TMPRSS2
transmembrane protease serine type 2
ARDS
acute respiratory distress syndrome
RBD
receptor binding domains
NAAT
nucleic acid amplification testing
WHO
world health organization
PCR
polymerase chain reaction
RT-PCR
reverse transcription polymerase chain reaction
qRT-PCR
real-time quantitative reverse transcription polymerase chain reaction
ORF
open-reading frames
LOD
limit of detection
POCT
point-of-care tests
RT-LAMP
reverse transcription loop-mediated isothermal amplification
BLF
bronchoalveolar lavage fluid
RdRp
RNA-dependent RNA polymerase
LRT
lower respiratory tract
Ag-RDT
Antigen-detecting rapid diagnostic test
ELISA
enzyme-linked immunosorbent assay
CLIA
chemiluminescence-immunoassay
IgM
immunoglobulin M
IgG
immunoglobulin G
IgA
immunoglobulin A
FDA
food and drug administration’s
US
United States
EUA
emergency use authorization
ICU
intensive care unit
WBC
white blood cell
NLR
neutrophil–lymphocyte ratio
PLRs
platelet-to-lymphocyte ratios
LDH
lactate dehydrogenase
AST
aspartate aminotransferase
ALT
alanine aminotransferase
CK
creatine kinase
PE
pulmonary embolism
DIC
disseminated intravascular coagulation
FDP
fibrinogen and fibrin degradation products
PT
prothrombin time
APTT
activated partial thromboplastin time
CSS
cytokine storm syndrome
IL-1β
interleukin 1β
IL-2
interleukin 2
IL-2R
interleukin 2R
IL-7
interleukin 7
IL-10
interleukin 10
IL-6
interleukin 6
G-CSF
granulocyte-colony stimulating factor
IFN-α
interferon α
IFN-γ
interferon γ
IP10
induced protein 10
MCP1
monocyte chemoattractant protein 1
MIP-1α
macrophage inflammatory protein-1α
TNF-α
tumor necrosis factor-α
VEGF
vascular endothelial growth factor
TRAIL
TNF related apoptosis inducing ligand
CRP
C-reactive protein
SAA
serum amyloid A protein
PCT
procalcitonin
RAS
renin-angiotensin system
Ang II
angiotensin II
Ang I
angiotensin I
MasR
Mas receptor
AT2R
AT2 receptor

Cited by (0)

1

Zhufeng Chen and Wanju Xu contributed equally to this work.

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