Analysis Of T-lymphocyte Subsets And Prognosis Relevant Factors In Patients With Severe Influenza A

BackgroundInfluenza A(Flu A)is a disease that causes severe respiratory infections i n humans and animals worldwide.Its strong infectivity,rapid virus mutation,r apid disease progression and other characteristics can cause a large number of deaths in patients infected by influenza A virus(IAV)every year.Flu A has be come a serious threat to human health.The host immune system plays an imp ortant role in the course of influenza A virus infection,which can be rapidly activated to defend against and clear the virus.Among host immune cells,cell ular immunity mediated by T-lymphocyte plays a crucial role in the fight agai nst influenza A virus.A number of studies have shown a decrease in lymphoc ytes in the peripheral circulation of patients infected by influenza A virus,but the exact mechanisms and effects remain unclear.AimAim of this study is to discuss the characters of T-lymphocyte subsets an d the general clinical features of patients with severe Flu A.Analyze the relat ed factors influencing the prognosis of patients with severe Flu A and their pr ediction accuracy.Raise clinical doctors' recognition of T-lymphocyte subsets of patients with severe Flu A.Prompt clinical doctors to estimate the prognosis of patients with severe Flu A by early test results.Promote the basic research of lymphocytes decrease mechanism and means of improving the immune funct ion.MethodsWe recruited 80 patients with severe Flu A who were admitted to the firs t affiliated hospital of ZhengZhou university from January 2018 to May 2019.They are divided into the survival group(n=55)and the death group(n=25)a ccording to their survival condition within 28d upon admission.Among them,t here are 31 patients who were in co-infection when admitted in hospital.Acco rding to the survival condition within 28d upon admission of these patients,th ey are divided into co-infection survival group(n=20)and co-infection death g roup(n=11).The age,gender,clinical manifestations,general test results(blood routine,organ function indicators,inflammatory indicators,etc.),T-lymphocyte subsets and other clinical characteristics of 80 patients are analyzed.SPSS21.0 was used for the statistical analysis.The counting data were described by fre quency,and the comparison between groups was conducted by the chi-square t est,the adjusted chi-square test,or the Fisher's exact probability test.The quant itative data conforming to normal distribution and homogeneity of variance wer e expressed as mean ± standard deviation(x±S),and T test was used for co mparison between groups.The quantitative data that did not conform to the nor mal distribution were represented by M(P25,P75),and the comparison betwee n groups was performed by Mann-whitney U test.Multicollinearity analysis wa s carried out on the significant variables in single factor analysis.Then,select th e variables according to the result of multicollinearity analysis.Multivariate C OX regression was used to analyze the influencing factors of survival time of patients with severe Flu A.Logistic regression was used to select the factors which have predictive value on the survival prognosis within 28d upon admissi on of patients with severe Flu A.Medcalc 19.2.0 was used to made receiver operating characteristic(ROC)curve.DeLong et al was used to compare the a rea under the ROC curve(AUC).Calculate the optimum cut-off value according to Youden index.Check level=0.05.Results(1)The mean age of the 80 patients with severe Flu A is 62.96 years in the death group,which is significantly higher than the survival group(P<0.05).There are 27 cases of respiratory failure in the survival group(49.1%)and 22 cases in the death group(88.0%).The incidence of respiratory failure in the death group is higher than that in the survival group(P<0.05).The absolute co unts of lymphocytes,albumin,globulins,CD3+T cells,CD4+T cells and CD8+T cells in the death group are significantly lower than those in the survival gro up(P<0.05),and the levels of procalcitonin,blood urea nitrogen,serum creatin ine and aspartate transaminase in the death group are significantly higher than those in the survival group(P<0.05).(2)The albumin,CD3+T cells,CD4+T cells,CD8+T cells in the co-infection death group are significantly lower than those in the co-infection survival grou p(P<0.05).(3)COX regression analysis showes that age,respiratory failure and aspart ate transaminase(AST)are risk factors affecting the survival time of patients w ith severe Flu A(P<0.05).Albumin and CD4+T cell count were protective facto rs affecting the survival time of patients with severe Flu A(P<0.05).The ROC curve showed that age,respiratory failure,AST and CD4+T cell count have p redictive value on the prognosis of patients with severe Flu A,but the predicti ve accuracy is low.The AUC are 0.665,0.695,0.672,0.728,respectively.The combination test of CD4+T cell,age,respiratory failure and AST whose AU C is 0.903 has preferably predictive accuracy.The optimal cut-off value of co mbination test score was 0.33.The sensitivity and specificity were 88.0%and 89.1%.Conclusion(1)Decrease in CD4+T cell count,elevation in age and aspartate transami nase,occurrence of respiratory failure and decrease in albumin can increase t he death risk of patients with severe Flu A.(2)Combination test of CD4+T cell count,age,respiratory failure and as partate transaminase has good predictive accuracy in the prognosis of patients with severe Flu A,and can be used as prognostic indicators in clinical practic e.