COVID-19 compromises iron homeostasis: Transferrin as a target of investigation.

IMPORTANCE: Since the beginning of the COVID-19 pandemic, numerous metabolic alterations have been observed in individuals with this disease. It is known that SARS-CoV-2 can mimic the action of hepcidin, altering intracellular iron metabolism, but gaps remain in the understanding of possible outcomes in other pathways involved in the iron cycle. OBJECTIVE: To profile iron, ferritin and hepcidin levels and transferrin receptor gene expression in patients diagnosed with COVID-19 between June 2020 and September 2020. DESIGN, SETTING AND PARTICIPANTS: Cross-sectional study that evaluated iron metabolism markers in 427 participants, 218 with COVID-19 and 209 without the disease. EXPOSURES: The primary exposure was positive diagnose to COVID-19 in general population of Santo André and São Bernardo cities. The positive and negative diagnose were determinate through RT-qPCR. MAIN OUTCOMES AND MEASURES: Devido a evidências de alterações do ciclo do ferro em pacientes diagnosticados com COVID-19 e devido a corregulação entre hepcidina e receptor de transferrina, uma análise da expressão gênica deste último, poderia trazer insights sobre o estado de ferro celular. A hipótese foi confirmada, mostrando aumento da expressão de receptor de transferrina concomitante com redução do nível de hepcidina circulante. RESULTS: Serum iron presented lower values in individuals diagnosed with COVID-19, whereas serum ferritin presented much higher values in infected patients. Elderly subjects had lower serum iron levels and higher ferritin levels, and men with COVID-19 had higher ferritin values than women. Serum hepcidin was lower in the COVID-19 patient group and transferrin receptor gene expression was higher in the infected patient group compared to controls. CONCLUSIONS AND RELEVANCE: COVID-19 causes changes in several iron cycle pathways, with iron and ferritin levels being markers that reflect the state and evolution of infection, as well as the prognosis of the disease. The increased expression of the transferrin receptor gene suggests increased iron internalization and the mimicry of hepcidin action by SARS-CoV-2, reduces iron export via ferroportin, which would explain the low circulating levels of iron by intracellular trapping.

Quantification of Vitamin D at Different Levels of Clinical Worsening of COVID-19.

INTRODUCTION AND AIM: Vitamin D is the name given to a group of lipid-soluble steroidal substances of physiological importance in the body, especially in bone metabolism. The active form of vitamin D is believed to have immunomodulatory effects on immune system cells, especially T lymphocytes, as well as on the production and action of several cytokines and on the expression of potent antimicrobial peptides in epithelial cells that line the respiratory tract, playing an important role in protecting the lung from infections. The aim of this study was to assess vitamin D levels in patients with COVID-19 in healthcare service and to verify that these levels are adequate to protect the progression of this infection. METHODS: The aim of this observational study was to evaluate the serum concentration of vitamin D in 300 patients suspected of being infected with COVID-19, treated at Basic Health Units (BHUs) and at the Hospital Complex in the municipality of São Bernardo do Campo. RESULTS: 294 patients were included, 195 (66%) of which tested positive for COVID-19 and 99 (34%) negative for COVID-19. Among the patients in the positive group, 163 patients were in the mild group (84%); 22 patients in the moderate group (11%); 8 patients in the severe group (4%), and 2 patients in the deceased group (1%). CONCLUSION: For the patients in this study, no association was observed for the protective factor of vitamin D against COVID-19 infection, and its role in controlling the clinical staging of the disease was not verified.