Lactate dehydrogenase level: A predictive marker for severe COVID-19 infection

Introduction: Coronavirus disease-2019 (COVID-19) has become a life-threatening healthcare crisis all over the world. Numerous biomarkers are currently under investigation to predict severity in this disease. Objective : This study aims to determine the possible association between increased lactate dehydrogenase (LDH) values odds of disease severity in COVID-19 patients. Methods: We conducted a descriptive study including 356 patients who were admitted to our pulmonology department, from September 2020 to December 2021, for COVID-19 pneumonia confirmed by RT-PCR. We assembled sociodemographic information, clinical data, baseline inflammatory markers including blood LDH levels and follow-up oxygen saturation levels from medical records. Results: The sample included 204 male (57,3%) and 152 female (42,7%) with a mean age of 63,51 ± 13,80 years. At admission, 51,9% of patients had initial oxygen requirements higher than 6 liters per minute. According to the clinical and biological severity, COVID-19 pneumonia was classified into 3 forms: mild form (9,5%), moderate form (29,1%), and severe form (61,6%). A total of 124 (64%) patients presented with elevated LDH values. A high level of blood LDH was positively associated with an important extent of lung abnormalities at CT scan (p=0.008), cardiovascular complications (p=0.041), and initial oxygen requirements higher than 6 liters per minute (p=0,034). Remarkably, elevated LDH values were found to be associated with the administration of antibiotics (p=0.014 ) and with death (p=0,049). Conclusion: Elevated LDH values were high in patients with severe COVID-19 pneumonia. LDH should be considered as a useful biomarker to predict severity in COVID-19.