Validation of Predictors of Disease Severity and Outcomes in COVID-19 Patients: A Descriptive and Retrospective Study

Abstract

Background: The severity and outcome of COVID-19 cases has been associated with the percentage of circulating lymphocytes (LYM%), levels of C-reactive protein (CRP), interleukin-6 (IL-6), procalcitonin (PCT), lactic acid (LA), and viral load (ORF1ab Ct). However, the predictive power of each of these indicators in disease classification and prognosis remains largely unclear. Methods: We retrospectively collected information on the above parameters in 142 patients with COVID-19, stratifying them by survival or disease severity. Findings: CRP, PCT, IL-6, LYM%, and ORF1ab Ct were significantly altered between survivors and non-survivors. LYM%, CRP, and IL-6 were the most sensitive and reliable factors in distinguishing between survivors and non-survivors. These indicators were significantly different between critically ill and severe/moderate patients. Only LYM% levels were significantly different between severe and moderate types. Among all the investigated indicators, LYM% was the most sensitive and reliable in discriminating between critically ill, severe, and moderate types and between survivors and non-survivors. Conclusions: CRP, PCT, IL-6, LYM%, and ORF1ab Ct, but not LA, could predict prognosis and guide classification of COVID-19 patients. LYM% was the most sensitive and reliable predictor for disease typing and prognosis. We recommend that LYM% be further investigated in the management of COVID-19.

Determinants of the outcomes of patients with cancer infected with SARS-CoV-2: results from the Gustave Roussy cohort

“…Emerging data on a cohort of 142 patients in which blood markers (CRP, procalcitonin, interleukin-6, lymphocyte count and viral load (ORF1ab Ct)) were explored as predictors of survival in patients with COVID-19 have recently shown that lymphopenia is the strongest predictor for severity disease in patients with COVID-19 (ref. 15 ). Of note, lymphopenia has long been established as a prognostic factor for overall survival in patients with cancer 16 .…”

Obesity and COVID-19: A Perspective from the European Association for the Study of Obesity on Immunological Perturbations, Therapeutic Challenges, and Opportunities in Obesity

“…It has been proposed that a combination of clinical and laboratory tests of ferritin, lymphocyte or leukocyte counts, platelet counts, erythrocyte counts, and sedimentation rate could be used to identify patients with COVID-19 at high risk of hyperinflammation [51]. Interestingly, results from a recent retrospective study, stratifying patients with COVID-19 by survival or disease severity, have suggested that percentage of circulating lymphocytes, levels of C-reactive protein, IL-6, procalcitonin, and viral load (ORF1ab Ct) could predict prognosis (survival/nonsurvival) and guide classification (moderate/severe/critically ill) of COVID-19 patients, with percentage of circulating lymphocytes being the most sensitive and reliable predictor for disease typing and prognosis [52]. Of note, it has recently been reported in the UK Biobank community cohort that the ApoE e4e4 allele predicts severe COVID-19, independent of preexisting dementia, cardiovascular disease, and type 2 diabetes [53].…”

Nonspecific blood tests as proxies for COVID-19 hospitalization: are there plausible associations after excluding noisy predictors?

“…The risk of overfitting was minimized by not accepting isolated variables in "ad hoc mined" models, and by applying causal criteria to evaluate associations. In comparison to other prediction studies, we identified a few focused on the transition from moderate to severe cases of COVID-19 [20,21,22,23,24,25,26,27]. Most studies recommend NLR and CRP as a predictor.…”

“…High levels of AUC at the negative stratum mean that CRP is a response with significant associations due to other causes than COVID-19. Differently from other prognostic studies[20,21,22,23,24,25] (none used data at negative stratum), CRP was excluded as candidate.…”