Journal of Clinical Medicine Research, ISSN 1918-3003 print, 1918-3011 online, Open Access
Article copyright, the authors; Journal compilation copyright, J Clin Med Res and Elmer Press Inc
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Case Report

Volume 12, Number 5, May 2020, pages 315-319

A Comprehensive Approach Is Vital for Diagnosing COVID-19: A Case of False Negative


Figure 1.
Figure 1. Different planes of the CT scan showing bilateral worsening of ground-glass opacities at bases. CT: computed tomography.
Figure 2.
Figure 2. Time course of the patient since the symptoms started until recovered and discharged.


Table 1. Summary of Laboratory Abnormalities
Laboratory findingsPatients value (normal values)
CRP: C-reactive protein; LDH: lactate dehydrogenase; INR: international normalized ratio; BMI: body mass index.
White blood cell count8.0 (4.8 - 10.8 × 109/L)
Absolute lymphocyte count1.5 (1.0 - 3.5 × 109/L)
Procalcitonin< 0.05 (< 0.05)
D-dimer186 (< 255 ng/mL)
CRP (high)13.2 (0.000 - 0.744 mg/dL)
LDH (high)390 (100 - 235 U/L)
Serum ferritin284 (11 - 307 ng/mL)
Erythrocyte sedimentation rate (high)59 (0 - 20 mm/h)
Respiratory viral panelNegative
Vitamin D (low)17 (> 30)
INR (high)1.3 (0.9 - 1.2)
BMI42.91 kg/m2


Table 2. Different Methods of Testing
Methods of testingWhat the test interpretsTurnaround time
ELISA: enzyme-linked immunosorbent assay; RDT: rapid diagnostic test.
Neutralization assayTests to look for active antibodies in subject serum which can inhibit virus growth ex vivo. Indicates if the patient is protected against future infection.3 - 5 days
ELISAQuantify the presence or absence of antibodies against the virus in the subject’s serum.1 - 5 h
RDTQualitatively tests for the presence or absence of antibodies against virus in the subject’s serum. Cannot quantify the antibody titer.10 - 30 min


Table 3. Diagnostic Tests Approved for COVID-19 in the USA as per FDA
Company/method of testingCountry of developmentSensitivity and specificity of the test
ELISA: enzyme-linked immunosorbent assay; COVID-19: coronavirus disease 2019; FDA: Food and Drug Administration; IgG: immunoglobulin G; RDT: rapid diagnostic test.
Mount Sinai laboratory COVID-19 ELISA IgG antibody test/ELISAUSANot available
VITROS Immunodiagnostic Products Anti-SARS-CoV-2 Total Reagent Pack/Total Calibrator (Ortho Clinical Diagnostics)/Modified ELISAUSASensitivity: 83%, specificity: 100%
Cellex/RDTUSA/ChinaSensitivity: 93.8%, specificity: 95.6%
ChemBio/RDTUSANot available
Epitope Diagnostics, Ltd/ELISAUSANot available
BioMedomics/RDT for research use onlyUSASensitivity: 88.66%, specificity: 90.63%
Ray Biotech/RDT for research use onlyUSANot available
Emory University/ELISA for research use onlyUSANot available