Disorder of Iron Metabolism as a Universal Pathogenetic Factor in Damage to Organs and Systems in Covid-19
Authors: Shikalova I. A. , Voznyuk I. A. , Lodyagin A. N. , Batotsyrenov B. V. , Timofeyeva N. V. , Pivovarova L. P. , Osipova I. V. , Polyakov I. A. , Ariskina O. B. , Borisenko A. N. , Rysev G. A. 
Published: August 2021

Relevance. The pathogenesis of COVID-19 remains one of the most pressing. The literature discusses the role of iron as a factor supporting inflammatory processes, hypercoagulability and microcirculation crisis in severe COVID-19.

The aim of study. was to identify changes in iron metabolism in patients with severe COVID-19 and hyperferritinemia.

Material and methods. In this study, we used a content analysis of available scientific publications and our own observations of the peculiarities of the clinical picture and laboratory parameters in patients with a severe course of COVID-19 who had hyperferretinemia at the height of the disease. The main group consisted of 30 patients hospitalized in the Department of Anesthesiology, Resuscitation and Intensive Care of N.A. Semashko City clinical Hospital No. 38 with the diagnosis COVID-19, bilateral polysegmental pneumonia, severe course and hyperferritinemia. The diagnosis of a new coronavirus infection was confirmed by visualization of bilateral viral lung lesions with chest CT-scan, positive PCR test for SARS-CoV-2 and the presence of immunoglobulins to SARS-CoV-2. The control group consisted of 20 healthy volunteers. The study evaluated the biochemical parameters of iron metabolism, fibrinolysis and markers of inflammation. Changes associated with impaired iron metabolism were assessed by the level of serum iron, transferrin, daily and induced iron excretion in the urine. Statistical processing was carried out using nonparametric methods.

Results. All patients with severe COVID-19 and hyperferritinemia showed signs of impaired iron metabolism, inflammation and fibrinolysis — a decrease in the level of transferrin (p<0.001), serum iron (p><0.005), albumin (p><0.001), lymphocytes (p><0.001) and an increase in leukocytes (p><0.001), neutrophils (p><0.001), CRP (p><0.005), IL-6 (p><0.001), D-dimer (p><0.005), daily urinary iron excretion (p><0.005) and induced urinary iron excretion (p><0.001). Conclusions The study showed that in the pathogenesis of the severe course of COVID-19, there is a violation of iron metabolism and the presence of a free iron fraction. The appearance of free iron can be caused by damage to cells with the “release” of iron from cytochromes, myoglobin, hemoglobin, or violation of the binding of iron to transferrin, which may be the result of a change in the protein structure or violation of the oxidation of iron to the trivalent state. When assessing the degree of viral effect on the body, one should take into account the effect of various regulators of iron metabolism, as well as an assessment of the level of free iron not associated with transferrin. Keywords: new coronavirus infection, COVID-19, SARS-CoV-2, iron metabolism, free iron, ferritin, transferrin, NTBI, nontransferrin bound iron>˂0.001), serum iron (p˂0.005), albumin (p˂0.001), lymphocytes (p˂0.001) and an increase in leukocytes (p˂0.001), neutrophils (p˂0.001), CRP (p˂0.005), IL-6 (p˂0.001), D-dimer (p˂0.005), daily urinary iron excretion (p˂0.005) and induced urinary iron excretion (p˂0.001).

Conclusions. The study showed that in the pathogenesis of the severe course of COVID-19, there is a violation of iron metabolism and the presence of a free iron fraction. The appearance of free iron can be caused by damage to cells with the “release” of iron from cytochromes, myoglobin, hemoglobin, or violation of the binding of iron to transferrin, which may be the result of a change in the protein structure or violation of the oxidation of iron to the trivalent state. When assessing the degree of viral effect on the body, one should take into account the effect of various regulators of iron metabolism, as well as an assessment of the level of free iron not associated with transferrin.