Biochemical, serological and immunological tests for diagnosis of coronavirus disease 2019 (COVID-19) patients: a comprehensive systematic review and meta-analysis

Recent studies have suggested the role of primary laboratory tests in addition to clinical symptoms for patients suspected to have coronavirus disease 2019 (COVID-19), which play a significant role in the diagnosis of COVID-19. However, the results of these studies are contradictory. The present study was conducted to evaluate biochemical, serological, and immunological tests for the diagnosis of COVID-19 patients.This study was presented in accordance with the PRISMA protocol. This protocol is registered with the code CRD42019145410 in PROSPERO. We conducted a comprehensive literature search in databases, including Web of Science, PubMed/Medline, CINAHL Scopus, Cochrane Library, EMBASE, Science Direct, and EBSCO to find citations from the beginning of January 2019 until the beginning of April 2020 without any restrictions.Finally, 51 studies, including 5,490 COVID-19 patients, were included in the present metaanalysis. The prevalence of different factors observed in laboratory findings was as follows: the prevalence of lymphopenia in patients with COVID-19 accounted for 51.6% (95% CI: 44.0-59.1), elevated C-reactive protein (CRP) was 63.6% (95% CI: 57.0-69.8), elevated erythrocyte sedimentation rate (ESR) was 62.5% (95% CI: 50.1-73.5), elevated tumor necrosis factor alpha (TNFα) was 28.7% (95% CI: 9.0-62.1), elevated serum amyloid-A level was 74.7% (95% CI: 50.0-89.7), elevated procalcitonin level was 72.6% (95% CI: 58.1-83.5), elevated interleukin-6 level was 59.9% (95% CI: 48.2-70.5), reduced CD3 level was 68.3% (95% CI: 50.1-82.2), reduced CD4 level was 62.0% (95% CI: 51.1- 71.6), elevated lactate dehydrogenase (LDH) level accounted for 53.1% (95% CI: 43.6-62.4), elevated brain natriuretic peptide (BNP) accounted for 48.9% (95% CI: 30.4-67.7), reduced albumin and reduced pre-albumin levels in patients with COVID-19 were estimated to be 54.7% (95% CI: 38.1-70.2) and 49.0% (95% CI: 26.6-71.8), and D-dimer level was 44.9% (95% CI: 31.0-59.6).The results show lymphopenia, elevated ESR level, elevated CRP level, elevated serum amyloid-A, elevated TNFα, elevated procalcitonin level, elevated interleukin-6 level, reduced CD3, reduced CD4, elevated BNP, elevated LDH, reduced albumin, reduced pre-albumin, and elevated Ddimer levels as the most common findings at the time of admission.