Total and Specific IgE in Sera of Patients Complaining Bronchoconstriction Post-COVID-19 Infection

The link between infections and hypersensitivity reactions was revealed by many pioneers. Many researchers found that detectable IgE is specific to bacteria and viruses in sera of infected patients. Some patients undergo a post-COVID-19 bronchospasm due to a reaction to the viral antigens. This study aimed to reveal the association between COVID-19 infection and respiratory allergy in post-COVID-19 convalescent patients. The blood specimens were taken from each of the patients and control individuals. Complete cell blood count (CBC), anti-COVID-19 virus IgM, IgG, as well as IL-5, total IgE and IgE specific for COVID-19 antigen were done for each of patients and control individuals. The results: no significant difference was found in the mean number of the total WBCs, neutrophil and monocyte cells between patients and control individuals. Patients who were suffering from bronchoconstriction and showed high total and specific IgE revealed normal percentage of eosinophil and high basophil. The basophil ratio undergoes an increase in COVID-19 patients who were suffering from bronchoconstriction during and after post-COVID-19 infection. Furthermore, a positive correlation was found between IL-5, total IgE, COVID-19 antigen specific IgE and basophils in patients while a normal relation was found between parameters and control individuals. We can conclude that bronchospasm is one of the post-COVID-19 complications, due to a hypersensitivity reaction to the viral antigens. The production of COVID-19 virus antigen specific IgE has an important role in post-infection allergy as well as its relation to other factors like IL-5 in patients’ sera.