Low transferrin levels predict heightened inflammation in patients with COVID-19: New insights.

OBJECTIVES: Mounting evidence links hyperinflammation in gravely ill patients to low serum iron levels and hyperferritinemia. However, little attention has been paid to other iron-associated markers such as transferrin. The aim of this study was to investigate the association of different iron parameters in severe COVID-19 and their relation to disease severity. SUBJECTS AND METHODS: This study involved 73 hospitalized patients with positive test results for SARS-CoV-2. Patients were classified into two groups according to symptom severity: mild and severe. Blood levels of anti-SARS-CoV-2 antibodies, interleukin 6 (IL-6), C-reactive protein (CRP), and iron-related biomarkers were measured. RESULTS: The results revealed a significant increase in IL-6, CRP, and ferritin levels and decreased transferrin and iron levels in severe COVID-19. Transferrin negatively predicted variations in IgM and IgG levels (P < 0.001), as well as 34.4% and 36.6% increase in IL-6 and CRP levels, respectively (P < 0.005). Importantly, transferrin was the main negative predictor of ferritin levels, determining 22.7% of serum variations (P < 0.001). CONCLUSION: Reduced serum transferrin and iron levels, along with the increased CRP and high ferritin, were strongly associated with the heightened inflammatory and immune state in COVID-19. Transferrin can be used as a valuable predictor of increased severity and progression of the disease.

Serum Iron Level as a Potential Predictor of Coronavirus Disease 2019 Severity and Mortality: A Retrospective Study.

BACKGROUND: Various types of pulmonary diseases are associated with iron deficiency. However, information on iron status in coronavirus disease 2019 (COVID-19) is scarce. METHODS: This study included 50 hospitalized patients with confirmed COVID-19. The role of serum iron in predicting severity and mortality of COVID-19 was evaluated. RESULTS: The most common symptoms of COVID-19 patients in this study were cough (82%), fever (64%), and chest distress (42%). Of the 50 patients, 45 (90%) patients had abnormally low serum iron levels (<7.8 µmol/L). The severity of COVID-19 was negatively correlated with serum iron levels before and after treatment and was positively correlated with C-reactive protein, serum amyloid A, D-dimer, lactate dehydrogenase, urea nitrogen, and myoglobin levels. Decreased serum iron level could predict the transition of COVID-19 from mild to severe and critical illness. Seven (53.8%) patients with a lower serum iron level after treatment in the critical group had died. There was a significant difference in posttreatment serum iron levels between COVID-19 survivors and nonsurvivors. CONCLUSIONS: Serum iron deficiency was detected in the patients with COVID-19. The severity and mortality of the disease was closely correlated with serum iron levels. Low serum iron concentration was an independent risk factor for death in COVID-19 patients.