Receiver operating characteristic (ROC) to determine cut-off points of clinical and biomolecular markers to discriminate mortality in severe COVID-19 living at high altitude.

BACKGROUND: In 2020, Ecuador had one of the highest death rates because of COVID-19. The role of clinical and biomolecular markers in COVID disease prognosis, is still not well supported by available data. In order for these markers to have practical application in clinical decision-making regarding patient treatment and prognosis, it is necessary to know an optimal cut-off point, taking into consideration ethnic differences and geographic conditions. AIM: To determine the value of clinical and biomolecular markers, to predict mortality of patients with severe COVID-19 living at high altitude. METHODS: In this study, receiver operating characteristic (ROC) curves, area under the curve (AUC) of ROC, sensitivity, specificity and likelihood ratios were calculated to determine levels of clinical and biomolecular markers that best differentiate survivors versus non-survivors in severe COVID subjects that live at a high altitude setting. RESULTS: Selected cut-off values for ferritin (≥ 1225 ng/dl, p = 0.026), IL-6 (≥ 11 pg/ml, p = 0.005) and NLR (≥ 22, p = 0.008) at 24 h, as well as PaFiO2 (≤ 164 mmHg, p = 0.015), NLR (≥ 16, p = p = 0.013) and SOFA (≥ 6, p = 0.031) at 72 h, appear to have good discriminating power to differentiate survivors versus non-survivors. Additionally, odds ratios for ferritin (OR = 3.38); IL-6 (OR = 17.07); PaFiO2 (OR = 4.61); NLR 24 h (OR = 4.95); NLR 72 h (OR = 4.46), and SOFA (OR = 3.77) indicate increased risk of mortality when cut-off points were taken into consideration. CONCLUSIONS: We proposed a straightforward and understandable method to identify dichotomized levels of clinical and biomolecular markers that can discriminate between survivors and non-survivors patients with severe COVID-19 living at high altitudes.

Neutrophil-to-lymphocyte ratio and mean platelet volume in the diagnosis of bacterial infections in COVID-19 patients. A preliminary analysis from Ecuador.

INTRODUCTION: Hospitalized COVID-19 patients are at risk of hospital infection. The neutrophil-to-lymphocyte ratio (NLR), lymphocyte-C-reactive protein ratio (LCR) and mean platelet volume (MPV) are established inflammation markers reflecting the systemic inflammatory response. The objective of this study was to evaluate the clinical characteristics of patients with COVID-19 and bacterial co-infections, as well as the correlation with NLR and MPV. METHODS: We assessed the role of the NLR and MPV in diagnosing bacterial infections in COVID-19 patients. The Wilcoxon test was used to compare the mean NLR and MPV between the diagnostic evaluation moments, while the Mann-Whitney test was used to compare NLR and MPV by sex and age. RESULTS: The NLR was compared three days before the culture and the day of taking the culture, observing significant differences (p=0.020). MPV three days before the culture and the day of the culture were compared, also observing significant differences (p=0.031). NLR and MPV were compared at the different evaluation times according to sex and age group, observing for the age group significant differences for the NLR three days before the culture (p=0.004). CONCLUSION: In our study, there were significant differences in NLR and MPV between the three days before culture and the day of culture. It is advisable to continue to enrol more patients in the study so that in the future, we can add results on the diagnostic accuracy of the NLR and MPV in the timely diagnosis of bacterial infection in patients with COVID-19.