Clinical laboratory parameters associated with severe or critical novel coronavirus disease 2019 (COVID-19): A systematic review and meta-analysis

Abstract

Background To date, several clinical laboratory parameters associated with Coronavirus disease 2019 (COVID-19) severity have been reported. However, these parameters have not been observed consistently across studies. The aim of this review was to assess clinical laboratory parameters which may serve as markers or predictors of severe or critical COVID-19. Methods and findings We conducted a systematic search of MEDLINE, Embase, Web of Science, CINAHL and Google Scholar databases from 2019 through April 18, 2020, and reviewed bibliographies of eligible studies, relevant systematic reviews, and the medRxiv pre-print server. We included hospital-based observational studies reporting clinical laboratory parameters of confirmed cases of COVID-19 and excluded studies having large proportions (>10%) of children and pregnant women. Two authors independently carried out screening of articles, data extraction and quality assessment. Meta-analyses were done using random effects model. Meta-median difference (MMD) and 95% confidence interval (CI) was calculated for each laboratory parameter. Forty-five studies in 6 countries were included. Compared to non-severe COVID-19 cases, severe or critical COVID-19 was characterised by higher neutrophil count (MMD: 1.23 [95% CI: 0.58 to 1.88] ×10 9 cells/L), and lower lymphocyte, CD4 and CD8 T cell counts with MMD (95% CI) of-0.39 (-0.47,-0.31) ×10 9 cells/L,-204.9 (-302.6,-107.1) cells/μl and-123.6 (-170.6,-76.6) cells/μl, respectively. Other notable results were observed for C-reactive protein (MMD: 36.

Association between markers of immune response at hospital admission and COVID‐19 disease severity and mortality: A meta‐analysis and meta‐regression

“…In addition, the potential impacts of duplicate reporting and important sources of bias were considered. Rather than simply exclude duplicate studies, as was done in a previous systematic review, 11 we conducted a sensitivity analysis showing that exclusion had little impact on overall results. Despite these strengths, there are multiple limitations to our study.…”

“…Such tools are often based on an understanding of disease pathophysiology, and in the case of COVID‐19, cytokine storm syndrome and thromboinflammation have surfaced as central and interconnected factors in the development of severe and fatal illness 7‐9 . These disease processes can be monitored using various biochemical and hematologic markers that are routinely measured at the time of hospitalization, potentially contributing to the accurate prediction of severity and mortality among patients hospitalized for COVID‐19 and allowing for early intervention 10,11 . However, the development of useful predictive tools incorporating laboratory parameters will require studies with large sample sizes covering broad population groups to be accurate and generalizable.…”

COVID-19-associated acute respiratory distress syndrome (CARDS): Current knowledge on pathophysiology and ICU treatment – A narrative review

“…According to a systematic review by Rodriguez and coworkers, the most prevalent changes in laboratory parameters are decreased albumin (75.8%), increased C-reactive protein levels (58.3%), followed by high lactate dehydrogenase levels (57.0%), and lymphopenia (43.1%) [ 76 ]. Furthermore, laboratory features that are typically abnormal in patients suffering from severe COVID-19 include elevated D-Dimer levels, ferritin, and Interleukin (IL)-6 levels, elevated cardiac biomarkers, and hepatic enzymes [ 11 , 77 , 80 , 81 ]. In cases where bacterial superinfection is suspected, procalcitonin might be helpful in addition to microbiological sampling, bronchoalveolar lavage, and galactomannan testing for fungal infection/aspergillosis [ 82 , 83 ].…”

The cytokine storm and thyroid hormone changes in COVID-19

“…are summarized in Table 1), the cytokine IL-6 [20-22, 27-29, 33, 36-45] and the chemokine CXCL10 [1, 20, 22-25, 27, 28, 31, 32, 35, 46, 47] have clearly emerged as recurrent markers of disease severity and poor outcome [38,41,42,48].…”