Effect Of Hemolysis On Total IgE In Human Serum At Room Temperature

[BACKGROUND]Anaphylactic shock,which is type I anaphylaxis in forensic work,is mainly mediated by IgE.It occurs rapidly and can be life-threatening in severe cases.But at present,the diagnosis of death cases of anaphylactic shock is mainly based on whether there is a confirmed history of allergies,specific allergens and the surrounding environment at that time.However,in postmortem autopsies,forensic workers can only see non-specific signs such as laryngeal edema,respiratory mucus obstruction and pulmonary congestion and edema,while in some other cases,microscopic examination can only find lack of specific pathomorphological changes.Therefore,the forensic diagnosis of anaphylactic shock death is a major challenge in forensic identification and can only be diagnosed on the basis of excluding other major diseases.At present,there is no gold standard for objective diagnosis.Therefore,in the identification of death cases of anaphylactic shock,the introduction of relevant biochemical indicators and study of their changes in the auxiliary diagnosis of anaphylactic shock has important practical significance in forensic medicine.Cadaveric blood is a common sample in forensic practice.In practice,cadaveric cryopreservation and postmortem changes often lead to severe hemolysis.A large number of studies have shown that hemoglobin and other substances released by erythrocyte rupture after hemolysis will affect the detection of indicators.However,at present,the change of serum total IgE content with postmortem interval has not been reported.[OBJECTIVES]The main purpose of this study is to explore the changes of total serum IgE content at different temperatures and different degrees of hemolysis after death,in order to provide a more accurate judgment for the forensic identification of anaphylactic shock death and death time estimation.[METHODS]Methods in this study,the blood of normal individuals and allergic individuals was obtained,and the grade of hemolysis was established.The IgE was stored at different temperatures（25℃and-20℃）for a period of time.The ELISA method was used to detect the IgE values under different degrees of hemolysis,and the changes of IgE at different temperatures and different degrees of hemolysis were observed,and the conclusion was obtained by SPSS analysis.In addition,the ELISA method and hospital detection method were compared to detect the total IgE of blood samples of individuals with actual allergies.[RESULTS]1.The content of serum total IgE increased at first and then decreased at room temperature.The degree of hemolysis had little effect on the detection value of serum total IgE when the degree of hemolysis was in grade 0～2.There was a linear correlation between the grade 0～3 of hemolysis and the concentration of total serum IgE（y=0.086x+0.276）,but the concentration of IgE was lower than the initial value after 7 days,so it could not be used as a basis for the diagnosis of allergy.2.There was a linear correlation between hemolysis degree and hemolysis time at room temperature（r=0.866）,regression equation:y=31.792x+29.739,and there was no difference in hemolysis rate between sexes.3.The total IgE OD value of allergic blood samples decreased with the extension of freezing days;heparin anticoagulant tube and EDTA-K₂anticoagulant tube had no effect on the detection of serum total IgE OD value.[CONCLUSION]1.The regression equation between the serum IgE OD value and the degree of hemolysis can be used to estimate the concentration of IgE at room temperature.2.The regression equation of hemolysis degree and hemolysis time can be used to estimate the time of death at room temperature.3.The total IgE OD value of allergic blood samples decreased with the prolongation of freezing days.