Serum Amyloid A (SAA) as Early Diagnosis of COVID-19 Disease: A Systematic Review and Meta-Analysis

Background and Aim: In December 2019, human-to-human transmission of respiratory illness (pneumonia) with fever and sputum was discovered in the respiratory tract, called COVID-19. Serum amyloid A (SAA) is an acute-phase plasma protein that is considered to be diagnostically superior to CRP in pathological conditions such as viral diseases. Therefore, the study question in this review is whether SAA as an indicator is involved in the early diagnosis of COVID disease. Materials and Methods: To identify related studies, we systematically searched international databases, including PubMed, Scopus, Science Direct, Cochrane, Embase, Web of Science, and Google Scholar search engine, without restriction on time until June 2021. Also, the Reference list of relevant studies was reviewed separately to find all existing articles in this field. Summary standardized mean difference (SMD) was estimated using random effects meta-analysis. Results: A total of 394 potentially relevant articles were identified from the initial search. After removing the duplicates and reading the title, abstract and full-text review, six studies were entered into the meta-analysis. There was a significant difference between the means of SSA among patients with a severe form of the disease compared to non-sever groups (SMD=-0.91, 95% CI: 1.18-1.59, -0.23) and with the control group (SMD=4.68, 95% CI: 1.18, 8.18). The Beggs and egger test results indicated no evidence of publication bias in the reported SMD. Conclusion: The result of our work indicates that SAA might potentially be used for the early diagnosis of COVID disease, but more studies are needed.