Is Fetal Hemoglobin a Key for Improvement of Hypoxia and Saving Last Breath in COVID-19 Patient?. A Pilot Study.

In December 2019, a sudden public health incident (the corona virus disease \[COVID-19\] epidemic) occurred in Wuhan, China. Clinical features of those with pneumonia include fever and cough, and in many cases a sudden and accelerating respiratory distress originated from interstitial pneumonia . Many hypotheses have explained hypoxemia in COVID-19 patients, such as hyperimmune reaction to viral infection and cytokine storm that leads to serious lung tissue and alveolar damage or even direct viral insult . Mortality are as high as 15% in critically ill patients requiring intensive care unit admission and oxygen therapy , suggesting an urgent need to try therapeutic interventions in addition to supportive treatment. There is more than one type of hemoglobin. In adults, Hb A or Adult hemoglobin which is the main hemoglobin in the blood. But there is another type of hemoglobin called fetal hemoglobin. Fetal hemoglobin (hemoglobin F, Hb F, or α2γ2) is the main oxygen carrier protein in the human fetus. and the levels remain high after birth until the baby is roughly 2-4 months old . Hemoglobin F has a different composition from hemoglobin A and higher affinity to oxygen . At birth, hemoglobin F accounts for 50-95% of the infant's hemoglobin and at around 6 months after birth, hemoglobin A becomes the predominant type.The key feature that allows hemoglobin F to bind more strongly to oxygen is by having γ subunits (instead of β, in Hb A for example). 2,3-BPG interacts much more with hemoglobin A than hemoglobin F . A hypothesis for the low incidence of the COVID-19 infection in pediatric is the presence of fetal hemoglobin (HbF) . In a preliminary study about the prevalence of hemoglobinopathies in different countries and the mortality rate of COVID-19, it appears that the mortality is lower in countries with a higher prevalence of hemoglobinopathies . Mice treated with GBT1118 (a compound that enhances the oxygen affinity of hemoglobin) showed a sustained significa