Laboratory Tests in the Diagnosis of COVID-19

Year 2020, Volume: 22 Issue: Special Issue, 5 - 9, 30.11.2020

Şemsi Nur Karabela Kadriye Kart Yaşar

https://doi.org/10.18678/dtfd.788691

Cited By: 1

Abstract

The gold standard for routine microbiological diagnosis of coronavirus disease 2019 (COVID-19) is quantitation of viral RNA in respiratory specimens by reverse-transcription polymerase chain reaction (RT-PCR). Detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) specific IgM and IgG antibodies in patient sera are additional diagnostic tests. It has been known that virus release begins a few days before clinical signs appear, and therefore, beginning from 2-3 days before the manifestation of clinical symptoms, virus RNA can be detected in the respiratory tract during the symptomatic period of the disease. Since the viral load is higher in lower respiratory tract samples such as bronchoalveolar lavage and tracheal aspirate, PCR positivity rate might be found higher compared to nasopharyngeal samples. Confirmatory PCR tests require specific equipment and trained personnel, and they are also time-consuming and costly. Antibody assays are simple, faster tests, do not require much equipment and applicable in any laboratory. They can even be performed with 2-3 drops of blood collected from the finger tip of patients using relatively inexpensive chromatographic-rapid tests. These tests can be used in the later period of the disease since specific antibodies appear on the 7-10th day of clinical signs in patients with COVID-19. Rapid antibody card tests have an average specificity and sensitivity, while antibody tests using microELISA have higher sensitivity and specificity.

Keywords

COVID-19, PCR, antibody, serology

COVID-19 Tanısında Laboratuvar Testleri

Abstract

Koronavirüs hastalığı 2019 (coronavirus disease 2019, COVID-19) için rutin mikrobiyolojik tanıda altın standart, solunum yolu örneklerinde viral RNA’nın gerçek zamanlı revers-transkriptaz polimeraz zincir reaksiyonu (RT-PCR) ile gösterilmesidir. Hasta serumunda şiddetli akut solunum yolu sendromu koronavirüsü 2 (severe acute respiratory syndrome coronavirus 2, SARS-CoV-2)’ye spesifik olan IgG ve IgM antikorların gösterilmesi de ek tanısal testlerdir. Virüs atılımının klinik bulgulardan birkaç gün öncesinden başladığı ve bu yüzden semptomların başlamasından 2-3 gün öncesinden itibaren klinik dönem boyunca virus RNA’sının solunum yollarında tespit edilebileceği bilinmektedir. Bronkoalveolar lavaj ve trakeal aspirat gibi alt solunum yolu örneklerinde viral yük daha fazla olduğundan PCR pozitiflik oranı nazofaringeal örneklere kıyasla daha yüksektir. Zaman alıcı ve pahalı olan doğrulayıcı PCR testleri, özel ekipman ve deneyimli personel gerektirir. Antikor testleri ise basit, hızlı sonuç verebilen, ciddi ekipman gerektirmeyen ve hemen her laboratuvarda yapılabilen testlerdir. Nispeten ucuz olan kramotografik hızlı kart testlerle parmak ucundan alınan 2-3 damla kanla, hasta başında bile yapılabilir. COVID-19 geçiren kişilerde hastalığın 7-10. gününden itibaren oluşan antikorlar sebebiyle, bu testler daha geç bir zamanda kullanılabilir. Hızlı antikor kart testleri ortalama bir özgüllük ve duyarlılığa sahipken, mikroELISA ile çalışılan antikor testlerinin duyarlılık ve spesivitesi ise daha yüksektir.

Keywords

COVID-19, PCR, antikor, seroloji

References

• Channappanavar R, Perlman S. Pathogenic human coronavirus infections: causes and consequences of cytokine storm and immunopathology. Semin Immunopathol. 2017;39(5):529-39.
• Pabbaraju K, Fox JD. Coronaviruses. In: Versalovic J, Carrol KC, Funke G, Jorgensen JH, Landry ML, Warnock DW, editors. Manual of clinical microbiology. 10th ed. Washington, DC: ASM Press; 2011. p.1410-22.
• Zhou Y, Yang Y, Huang J, Jiang S, Du L. Advances in MERS-CoV vaccines and therapeutics based on the receptor-binding domain. Viruses. 2019;11(1):60.
• Drosten C, Günther S, Preiser W, van der Werf S, Brodt HR, Becker S, et al. Identification of a novel coronavirus in patients with severe acute respiratory syndrome. N Engl J Med 2003;348(20):1967-76.
• Lu R, Zhao X, Li J, Niu P, Yang B, Wu H, et al. Genomic characterisation and epidemiology of 2019 novel coronavirus: implications for virus origins and receptor binding. Lancet. 2020;395(10224):565-74.
• Özturk R, Taşova Y, Ayaz A. COVID-19: pathogenesis, genetic polymorphism, clinical features and laboratory findings. Turk J Med Sci. 2020;50(SI-1):638-57.
• Liang LL, Tseng C, Ho HJ, Wu CY. Covid-19 mortality is negatively associated with test number and government effectiveness. Sci Rep. 2020;10(1):12567.
• Bonadad C, García-Blas S, Tarazona-Santabalbina F, Sanchis J, Bertomeu-González V, Fácila L, et al. The effect of age on mortality in patients with COVID-19: A meta-analysis with 611,583 subjects. J Am Med Dir Assoc. 2020;21(7):915-8.
• Öcal D, Vezir S, Karahan ZC. Mikrobiyolojik tanı yöntemleri. In: Memikoglu O, Genç V, editors. COVID-19. Ankara, Turkey: Ankara Üniversitesi Basımevi; 2020. p.17-27.
• Yang Y, Yang M, Shen C, Wang F, Yuan J, Li J, et al. Evaluating the accuracy of different respiratory specimens in the laboratory diagnosis and monitoring the viral shedding of 2019-nCoV infections. MedRxiv. 2020. doi:10.1101/2020.02.11.20021493
• Jiang F, Deng L, Zhang L, Cai Y, Cheung CW, Xia Z. Review of the clinical characteristic of coronavirus disease 19 (COVID-19). J Gen Intern Med. 2020;35(5):1545-9.
• Imai K, Tabata S, Ikeda M, Nocuchi S, Kitagawa Y, Matuoka M, et al. Clinical evaluation of an immunochromatographic IgM/IgG antibody assay and chest computed tomography for the diagnosis of COVID-19. J Clin Virol. 2020;128:104393.
• Anudeep TC, Jeyaraman M, Shetty DU, Raj MH, Ajay SS, Somasundaram R, et al. Convalescent plasma as a plausible therapeutic option for nCOVID-19: A Review. J Clin Trials. 2020;10(3):409.
• Ai T, Yang Z, Hou H, Zhang C, Chen C, Lv W, et al. Correlation of chest CT and RTPCR testing in coronavirus disease 2019 (COVID-19) in China: A report of 1014 cases. Radiology. 2020;296(2):E32-40.
• Huang YH, Jiang D, Huang JT. SARS-CoV-2 detected in cerebrospinal fluid by PCR in a case of COVID-19 encephalitis. Brain Behav Immun. 2020;87:149.
• Xia J, Tong J, Liu M, Shen Y, Guo D. Evaluation of coronavirus in tears and conjunctival secretions of patients with SARS-CoV-2 infection. J Med Virol. 2020;92(6):589-94.
• Yu F, Yan L, Wang N, Yang S, Wang L, Tang Y, et al. Quantitative detection and viral load analysis of SARS-CoV-2 in infected patients. Clin Infect Dis. 2020;71(15):793-8.
• hsgm.saglik.gov.tr [Internet]. T.C. Sağlık Bakanlığı Halk Sağlığı Genel Müdürlüğü. COVID-19 (SARS-CoV-2 Enfeksiyonu) Rehberi [Cited: 2020 August 31]. Available from: https://dosyamerkez.saglik.gov.tr/ Eklenti/37044,covid-19rehberipdf.pdf?0.
• Corman VM, Landt O, Kaiser M, Molenkamp R, Meijer A, Chu DKW, et al. Detection of 2019 novel coronavirus (2019-nCoV) by real-time RT-PCR. Euro Surveill. 2020;25(3):2000045.
• Tang MS, Hock KG, Logsdon NM, Hayes JE, Gronowski AM, Anderson NW, et al. Clinical performance of two SARS-CoV-2 serologic assays. Clin Chem. 2020;66(8):1055-62.
• Okba NMA, Müller MA, Li W, Wang C, GeurtsvanKessel CH, Corman VM, et al. Severe acute respiratory syndrome coronavirus 2-specific antibody responses in coronavirus disease patients. Emerg Infect Dis. 2020;26(7):1478-88.
• Theel ES, Slev P, Wheeler S, Couturier MR, Wong SJ, Kadkhoda K. The role of antibody testing for SARS-CoV-2: Is there one? J Clin Microbiol. 2020;58(8):e00797-20.
• idsociety.org [Internet]. Infectious Diseases Society of America. IDSA COVID-19 Antibody Testing Primer [Cited: 2020 August 31]. Available from: https://www.idsociety.org/globalassets/idsa/public-health/covid-19/idsa-covid-19-antibody-testing-primer.pdf.
• who.int [Internet]. World Health Organization. "Immunity passports" in the context of COVID-19, scientific brief. [Cited: 2020 August 31]. Available from: https://apps.who.int/iris/rest/bitstreams/1275788/retrieve
• Shen C, Wang Z, Zhao F, Yang Y, Li J, Yuan J, et al. Treatment of 5 critically Ill patients with COVID-19 with convalescent plasma. JAMA. 2020;323(16):1582-9.
• Duan K, Liu B, Li C, Zhang H, Yu T, Qu J, et al. Effectiveness of convalescent plasma therapy in severe COVID-19 patients. Proc Natl Acad Sci USA. 2020;117(17):9490-6.
• Bloch EM, Shoham S, Casadevall A, Sachais BS, Shaz B, Winters JL, et al. Deployment of convalescent plasma for the prevention and treatment of COVID-19. J Clin Invest 2020;130(6):2757-65.
• fda.gov [Internet]. Food and Drug Administration. Coronavirus Disease 2019 (COVID-19) Emergency Use Authorizations for Medical Devices [Cited: 2020 August 31]. Available from: https://www.fda.gov/medical-devices/emergency-use-authorizations-medical-devices/coronavirus-disease-2019-covid-19-emergency-use-authorizations-medical-devices.
• Zhao J, Yuan Q, Wang H, Liu W, Liao X, Su Y, et al. Antibody responses to SARS-CoV-2 in patients of novel coronavirus disease 2019. Clin Infect Dis. 2020;[Epub ahead of print]. doi: 10.1093/cid/ciaa344.
• Tay MZ, Poh CM, Rénia L, MacAry PA, Lisa FPNg. The trinity of COVID-19: immunity, inflammation and intervention. Nat Rev Immunol. 2020;20(6):363-74.
• Farnsworth CW, Anderson NW. SARS-CoV-2 serology: much hype, little data. Clin Chem. 2020;66(7):875-7.
• Krüttgen A, Cornelissen CG, Dreher M, Hornef M, Imöhl M, Kleines M. Comparison of four new commercial serologic assays for determination of SARS-CoV-2 IgG. J Clin Virol. 2020;128:104394.
• Solodky ML, Galvez C, Russias B, Detourbet P, N'Guyen-Bonin V, Herr AL, et al. Lower detection rates of SARS-CoV2 antibodies in cancer patients versus health care workers after symptomatic COVID-19. Ann Oncol. 2020;31(8):1087-8.
• Zhao R, Li M, Song H, Chen J, Ren W, Feng Y, et al. Early detection of SARS-CoV-2 antibodies in COVID-19 patients as a serologic marker of infection. Clin Infect Dis. 2020;[Epub ahead of print]. doi: 10.1093/cid/ciaa523.