2.3 Laboratory tests
The SARS-CoV-2 viral nucleic acid detection on the pharyngeal swab
specimens of each patient from the two hospitals were processed by
technicians from Zhongnan Hospital of Wuhan University, using rRT-PCR
assay.14 According to the recommendation issued by the
National Institute for Viral Disease Control and Prevention
(China),15 a cycle threshold value (Ct-value) less
than 37 was defined as a positive test result, whereas a Ct-value of 40
or more was defined as a negative test. All rRT-PCR assays were
performed with the same kit.
The complete blood counts, biochemical parameters and variables
reflecting hepatic and renal functions on admission and data of
follow-up laboratory tests during hospital stay were collected for each
patient, including leucocytes and platelets, neutrophils, lymphocytes,
monocytes, eosinophils, basophils, C-reactive protein (CRP), serum
amyloid A (SAA), procalcitonin (PCT), D-dimer, serum creatine kinase
(CK), creatine kinase-MB (CK-MB), alanine aminotransferase (ALT),
aspartate aminotransferase (AST), blood urea nitrogen (BUN) and serum
creatinine.
Serum and respiratory samples, such as pharyngeal swabs were used for
detection of co-infected other pathogens, such as Mycoplasma pneumoniae,
Chlamydia pneumoniae, Coxsackie virus group B, adenovirus, echovirus,
respiratory syncytial virus, EpsteināBarr virus, influenza A virus,
influenza B virus, parainfluenza, cytomegalovirus, Gram-positive or
Gram-negative bacteria, and fungi.