Serum IL-6: A potential biomarker of mortality among SARS-CoV-2 infected patients in Mexico.

BACKGROUND: The first case of SARS-CoV-2 in Mexico was reported in February 2020, since then, high rates of mortality due to COVID-19 have been found. Cytokine storm is linked to the severity and decreasing the survival among infected patients by COVID-19. The serum levels of Interleukin 6 (IL-6) have been correlated to mortality in COVID-19 cases and could be used as indicator of mortality in COVID-19 cases. The aim of this study was to determine levels of IL-6 and assess its usefulness as indicator of mortality among COVID-19 patients from Mexico. METHODS: A cohort study among 38 adults (28 men, 10 women) was carried out in the Regional High Specialty Hospital of the Yucatan Peninsula in Merida, Yucatan, Mexico. Demographic and clinical biochemistry data were collected. The serum levels of IL-6 were measured in each patient by specific immunoassays. RESULTS: High frequency of mortality (36.84%) was found in the sample. The average age of individuals that non-survive was significantly higher (59.71 ± 13.83 years) than the survival group (43.29 ± 11.80 years). Serum levels of IL-6 were significantly higher in patients that did not survive. A correlation between IL-6 levels with lymphocyte count, LDH, CRP and procaciltonin was found. The optimal cutoff value of IL-6 was 30.95 pg/mL with high sensitivity and specificity. CONCLUSION: Our findings demonstrate that level of IL-6 is an indicator of mortality among hospitalized COVID-19 patients in Mexico.

Pulmonary function and functional capacity in COVID-19 survivors with persistent dyspnoea.

The purpose of this study was to examine the physiological mechanisms of persistent dyspnoea in COVID-19 survivors. Non-critical patients (n = 186) with varying degrees of COVID-19 severity reported persistent symptoms using a standardized questionnaire and underwent pulmonary function and 6-minute walk testing between 30 and 90 days following the onset of acute COVID-19 symptoms. Patients were divided into those with (n = 70) and without (n = 116) persistent dyspnoea. Patients with persistent dyspnoea had significantly lower FVC (p = 0.03), FEV1 (p = 0.04), DLCO (p = 0.01), 6-minute walk distance (% predicted, p = 0.03), and end-exercise oxygen saturation (p < 0.001), and higher Borg 0-10 ratings of dyspnoea and fatigue (both p < 0.001) compared to patients without persistent dyspnoea. We have shown that dyspnoea is a common persistent symptom across varying degrees of initial COVID-19 severity. Patients with persistent dyspnoea had greater restriction on spirometry, lower DLCO, reduced functional capacity, and increased exertional desaturation and symptoms. This suggests that there is a true physiological mechanism that may explain persistent dyspnoea after COVID-19.

Risk Factors for Mortality in Hospitalized Patients with COVID-19: An Overview in a Mexican Population.

BACKGROUND: Currently, Mexico ranks third worldwide in mortality due to coronavirus disease pandemic 2019 (COVID-19) and reliable information is scarce, with the available data focused on epidemiological characteristics. This study aimed to identify the risk factors associated with mortality and outcomes in hospitalized Mexican patients with COVID-19. METHODS: We prospectively assessed patients admitted to a COVID-19 reference center in southeast Mexico between March 28 and June 30, 2020. Mortality was defined as survivors or non-survivors and univariate and multivariate logistic regression analyses were performed to explore the association of the clinical characteristics and laboratory parameters with mortality. RESULTS: We included 200 patients with a mean age of 55 years, 69% were men and 72% had at least one chronic comorbidity. Eighty-six patients required invasive mechanical ventilation (IMV) with an overall mortality rate of 82.5%. Only 51% of the patients with IMV were admitted to the intensive care unit (ICU), with a survival rate of 27.3%, but only 7.2% for patients without ICU admissions (p=0.014). The multivariate analysis found that a neutrophil-to-lymphocyte ratio ≥9 (odds ratio [OR], 4.64; 95% confidence interval [CI], 2.05-10.53) albumin <3.5 g/dL (OR, 3.76; 95% CI, 1.56-9.07), lactate dehydrogenase (LDH) level ≥725 U/L (OR, 5.45; 95% CI, 2.36-12.57), and IMV (OR, 64.7; 95% CI, 15.20-275.39) were independent risk factors associated with mortality. CONCLUSION: Neutrophil-to-lymphocyte ratio, LDH, albumin, and IMV were independent risk factors for mortality in Mexican patients with COVID-19. Also, the availability of ICU resources is invaluable for better outcomes in critically ill patients. Our results could provide clinical information for timely decision-making in low-and-middle income countries to overcome the pandemic.