The Risk Prediction Model Establishment Of Steroid-Refractory Patients In Primary Immune Thrombocytopenia

Objective:Primary immune thrombocytopenia(ITP)is a common bleeding disorder.Corticosteroid therapy including prednisone and dexamethasone is the firstline treatment recommended in ITP practical guidelines.However,nearly 30%of ITP patients appear steroid-refractory,and only 5-30%can achieve a long-term complete hematologic remission.Our research analyses the relevant indicators of our patients to obtained some risk factors and established the risk prediction model that can be used to predict the poor response to glucocorticoid in ITP patients.Methods:We comprehensively collected data from 111 ITP patients admitted to our hospital from 05/2013 to 05/2019.We performed univariate and multivariate analyses to get the risk factors and established the risk prediction model that can be used to predict the poor response to glucocorticoid in ITP patients.Then data from 65 new ITP patients were collected to evaluate the accuracy of the prediction model.Results:The results of univariate and multivariate regression analysis showed that the elevation of serum ferritin levels(OR=2.764,95%CI 1.044-7.320),patients’age(OR=1.025,95%CI 1.001-1.049),and positive expression of Hepatitis B Surface Antigen(HBsAg,OR=3.682,95%CI 1.595-8.501)were the independent risk factors of the poor response to corticosteroid.Regression equations for steroid-resistant ITP patients were:P=ex/(1+ex),x=-2.015+0.024×patients’ age+1.017 serum ferritin level+1.294 HBsAg.It found that when x=1.13,the prediction model meets the optimal threshold.Though ROC curve analysis and external validation,the model appears good forecasting performance.Conclusion:We found that elder ITP patients with a high level of serum ferritin and positive expression of HBsAg had a poor response to first-line corticosteroid therapy which are high-risk factors for the unsatisfactory treatment of ITP.For each one-year increase in age(≥18 years old),the risk of steroid-refractory increased by 1.025 times.For the patients with a high level of serum ferritin,the risk of steroidrefractory increased by 2.764 times.For the patients with positive expression of HBsAg,the risk of steroid-refractory increased by 3.682 times.The risk prediction model can be used when we treat ITP patients.For the patients calculated with x≥1.13 which is suggested that he or she may have a poor response to glucocorticoid therapy.Secondline therapies such as TPO-RAs can be considered.