Overview of Pathology and Laboratory Features of COVID-19

BACKGROUND: The third identified severe respiratory disease in the past two decades and the first to result in a pandemic is the coronavirus disease 2019 (COVID-19) specifically caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). AIM: The aim of this study was to provide an overview of the basic pathology and diagnostic laboratory features of COVID-19. METHODS: This review involved search of literatures on PubMed, Science alert, Medline, and Advanced Google search using the keywords “SARS-CoV2,” “Coronavirus” along with “pathology of COVID-19” and “diagnosis of COVID-19” with related articles pooled, relevant information extracted, and properly referenced. RESULTS: The recommended method of diagnosis is by nucleic acid testing of the viral ribonucleic acid in which real-time reverse-transcription polymerase chain reaction followed by nucleic acid sequencing when required is performed while some serologic techniques developed include enzyme-linked immunosorbent assay, immunochromatographic lateral flow assay, neutralization bioassay, and specific chemosensors to detect the immunoglobulin M and immunoglobulin G antibodies produced, although sole use of serologic tests is highly discouraged by monitoring agencies. The hematological features display leukocytosis with lymphocytopenia, eosinopenia, reduced procalcitonin along with increased D-dimer, C-reactive protein, serum amyloid A, fibrin, fibrin degradation products, and some inflammatory markers such as interleukin (IL)-2, IL-6, IL-7, IL-10, granulocyte colony-stimulating factor, MCP10, interferon gamma-induced protein 10, and tumor necrosis factor-α. The pathologic presentations include pleurisy, lung consolidation, pulmonary edema and pericarditis along with other features of acute respiratory syndrome, myocardial injury, and acute kidney injury. CONCLUSION: There are highly efficacious and reliable methods of diagnosis of COVID-19 which also determine the stage and severity of the condition, and these methods are performed in line with specific clinical presentations. However, more studies are required to identify the capabilities, characteristics, and tendencies of this novel virus.