A Review on Laboratory Findings of Patients with COVID-19 Infection

Aims: This study aimed to evaluate the diagnostic and laboratory findings of infections caused by acute coronavirus syndrome 2 (SARS-CoV-2). Information Methods: This systematic review was carried out using research in Google Scholar, international databases such as Pubmed, Wiley, and Sciencedirect, and Iranian databases including SID and Magiran by the keywords SARS-CoV-2, COVID-19 diagnostic methods, PCR, COVID-19, and hematology parameters. Finally, 93 articles were selected and reviewed. Findings: Reverse transcription-polymerase chain reaction and molecular test methods are the method of choice to diagnose the cause of SARS-CoV-2 infection. Serological testing is not yet sensitive enough and specific for diagnosis. The clinical spectrum of the infection is wide, including asymptomatic infection, relatively mild upper respiratory tract disease, and severe viral pneumonia with respiratory failure and even death. The incidence of lymphopenia, thrombocytopenia, and coagulation disorders occur in severe cases of the disease and are associated with a poor prognosis. An increase of D-dimer levels in severe cases of the disease suggests anticoagulant therapy. In severe disease, laboratory tests show changes in the immune system with overstimulation of the cytokine storm. In addition, biomarkers of specific organs indicate heart, kidney, and liver dysfunction in many patients. Conclusion: Although virus detection by reverse transcription-polymerase chain reaction is the gold standard, if the test is negative, the definitive diagnosis of COVID-19 should be based on clinical data; other tests for complications of the disease are also important.