The analysis of Fe-dependent serum enzymes in severe COVID-19 with a pulmonary thrombotic event

Introduction:
COVID-19 patients in critical condition requiring ICU admission are more likely to experience thromboembolic complications, especially pulmonary embolism. Since the outbreak of coronavirus disease 2019 (COVID-19), clinicians have struggled with the attempt to diagnose and manage the severe and fatal complications of COVID-19 appropriately. Several reports have described significant procoagulatory events, including life-threatening pulmonary embolism, in these patients. The aim of the study was to analyze the results of selected serum enzymes in patients with a radiologically confirmed pulmonary thrombotic event based on the pulmonary tissue involvement assessed in a computed tomography (CT) scan.

Material and methods:
The retrospective study covered a group of 226 COVID-19 patients. Groups were divided based on the degree of lung tissue involvement in CT examinations, including patients with confirmed pulmonary embolism. The analyzed group consisted of 136 men and 90 women with mean age of 70 years.

Results:
The group consisted of patients with < 50% of lung volume changes who had higher parameter values in each analyzed parameter, except red blood cells (RBC) (p < 0.05). Especially, the level of ferritin was much higher in the first group (p = 0.000008). Elevated ferritin levels were observed in all patients with lung tissue involvement.

Discussion:
This line of research is critical in order to assess the predisposing conditions for pulmonary embolism occurrence in COVID-19, which can be used as a predictive factor for course of the disease. The conducted research will resolve whether there is a relationship between the selected laboratory parameters and the occurrence of pulmonary embolism in patients with COVID-19.

Conclusions:
The study demonstrated that elevated levels of several inflammatory and thrombotic parameters such as ferritin, D-dimer, C-reactive protein (CRP) as well as hemoglobin do not correlate with the degree of lung tissue involvement in the computed tomography image.