Evaluation of the Relationship Between Lactate Dehydrogenase/Lymphocyte Ratio with Interleukin-6 Levels in Hospitalized Patients with COVID-19

Abstract

Introduction: Clinical picture of Coronavirus disease-2019 (COVID-19) ranges from mild respiratory symptoms to severe respiratory failure and death. To determine the severity of the disease; lymphocyte count, lactate dehydrogenase (LDH), C-reactive protein (CRP), D-dimer and interleukin-6 (IL-6) levels are the parameters that are used. In this study, it was aimed to evaluate effect of LDH/lymphocyte ratio on prognosis and whether there was a correlation between LDH/lymphocyte ratio and IL-6 in hospitalized patients with COVID-19. Materials and Methods: Patients who were aged 18 years and older, were positive for Severe acute respiratory syndrome-Coronavirus-2 polymerase chain reaction test, had COVID-19 pneumonia findings on tomography, and hospitalized for at least three days were included in the study. Results: The mean age of the patients was 59.35±15.23 year and 56 (59.6%) of patients were male. Fifty seven (60.6%) of the patients had comorbid diseases. The 14- and 28-day mortality rates were 14.9% and 27.7%, respectively. There was a statistically significant correlation between hospitalization in intensive care unit and LDH, lymphocyte count, LDH/lymphocyte ratio, CRP, highest D-dimer, initial IL-6, neutrophil/lymphocyte ratio, and highest IL-6 values (p<0.05). The IL-6 level, highest D-dimer level, LDH/lymphocyte ratio and CRP level of the patients who died were significantly higher than those who were survivors (p<0.05). A positive and significant correlation was found between the LDH/lymphocyte ratio and both the first admission and the highest IL-6 levels. In ROC analysis, LDH/lymphocyte ratio values of 0.53 and above [AUC: 0.758 (95% CI: 0.660-0.855)] were found to have a specificity of 61% and sensitivity of 70.7% in showing the IL-6 level of 80 pg/ml and above at first admission. Conclusion: In this study, a significant correlation was found between the LDH/lymphocyte ratio and the IL-6 values. As a result of this study, even if IL-6 cannot be measured, the ratio of LDH/lymphocyte that can be measured in most centers, is thought to be an important marker in predicting poor clinical course.

Keywords

• covid-19
• interleukin-6
• lactate dehydrogenase/lymphocyte