Abstract
Background: Inlate 2019, a new coronavirus disease was detected in Wuhan, China and called COVID-19. There are so many unknown factors about the virus. Iron metabolism is one of the topics have to be investigated for the development of therapeutic strategies for COVID-19. The aim of this study is to assess sequential changes in traditional biochemical iron status indicators during COVID-19 pneumonia.
Methods: A case-control study. Case group was defined as pneumonia with PCR-confirmed SARS-CoV-2 and the control group consisted of patients with non-COVID-19 pneumonia. Biomarkers of anemia and iron metabolism, CRP, procalcitonin were analyzed. Demographic features, CT findings, SpO2, development of ARDS, ICU admission, duration of hospitalization, discharge status (event free survival or death) were evaluated.
Results: 205 hospitalized patients with pneumonia were analyzed retrospectively. COVID-19 group was significantly younger than control group. 23 of 106 patients had critical COVID-19 infection. Comorbidity frequency and mortality rate of patients with COVID-19 pneumonia were significantly higher. Hb, RET-He, iron, TSAT, CRP, PCT and SpO2 were significantly lower. Hb, RET-He, iron, TSAT levels significantly correlated to lung aeration loss, hospitalization day and inflamatory markers in COVID-19 pneumonia.
Conclusion: The patients with COVID-19 pneumonia had iron deficiency anemia even they were young. Iron deficiency may effect the lung aeration loss related to paranchimal infiltrations of COVID-19 and mortality of the patients with COVID-19 pneumonia. Our data indicates that iron deficiency is associated with longer hospital stays, lower oxygenation, higher CRP and procalsitonin.
Keywods: COVID-19, pneumonia, iron, hemoglobin, anemia
Introduction Inlate 2019, a new coronavirus with acute respiratory disease was detected in Wuhan, China and called SARS-COV-2 (Severe Acute Respiratory Syndrome Coronavirus-2) (1). The name of the disease has been determined as Coronavirus disease 2019 (COVID-19) by the World Health Organization.
The diagnosis includes the presence of contact, findings compatible with viral pneumonia in lung imaging, and laboratory findings not specific to COVID-19 (such as lymphopenia, d-dimer, ferritin elevation, etc.). Although reverse transcription polymerase chain reaction (RT-PCR) for SARS-COV-2 is the gold standard in diagnosis, errors in sampling result in false negativity in the period of the disease.
The most common symptoms are fever, cough, and dyspnea. Pneumonia, severe acute respiratory tract infection, renal failure, sepsis/septic shock, ARDS, and multiorgan failure or even death may develop in more severe cases (2).
Since the life cycle of SARS-COV-2 has not been fully revealed, there are still unknown points about the disease. Diagnosis, follow-up and treatment algorithms are tried to be explained.
A study evaluating the biological roles of some proteins of the novel coronavirus (3) showed the ORF8 and surface glycoprotein could bind to the porphyrin. The researchers speculated that orf1ab, ORF10, and ORF3a proteins could coordinate attack the heme on the 1-beta chain of hemoglobin to dissociate the iron to form the porphyrin. Thus, it has been claimed that hemoglobin, which can carry oxygen and carbondioxide, is reduced, lung cells are damaged due to the inadequate exchange of carbondioxide and oxygen, and groundglass densities appear in lung imaging due to inflammatory response.
Anaemia screening only based on hemoglobin measurements is inappropriate and inconclusive in many subjects. Iron deficiency anemia (IDA) is one of the most common form of anemia. Various biochemical parameters are used to diagnose IDA, including ferritin, transferin saturation (TSAT), serum iron, and mean corpuscular volume (MCV). However, measures of mature erythrocyte indices MCV, mean corpuscular hemoglobin (MCH), and red blood cell distribution width (RDW) cannot detect early iron-deficient erythropoiesis due to the slow turnover of erythrocytes in circulation (4). Cellular iron status can be determined by the method of measuring the reticulocyte hemoglobin equivalent (RET-He) (5). RET-He reflects a ‘shortterm’ indication concerning the status of reticulocytes hemoglobinization (6).
Serum ferritin is an important parameter in determining iron deficiency anemia. Serum ferritin concentration generally correlates with total body iron storage. However, despite the presence of iron deficiency in the course of liver parenchymal disease, chronic inflammatory diseases, some infections and storage diseases, normal serum ferritin level can be found, as well as in hypothyroidism, pregnancy and vitamin C deficiency, it may be low because ferritin synthesis is decreased (7).
Reticulocytes are the youngest erythrocytes released from bone marrow in to blood. The reticulocyte hemoglobin content (RET-He) indicates the amount of iron available in the bone marrow for hemoglobin production. Therefore, RET-He has been proposed as an indicator of iron status (8). In this study; we assessed sequential changes in traditional biochemical iron status indicators during Covid-19 infection.