Correlation Analysis Of Risk Factors For Relapse Of Primary Immune Thrombocytopenia In Children

Objective To analyze risk factors for relapse of childhood primary immune thrombocytopenia(ITP),explore the risk factors associated with relapse in children,so as to provide possible relevant predictors for ITP relapse early in treatment,improve the course and outcome of the disease and reduce the relapse rate.Methods1.211 cases of newly diagnosed ITP were confirmed,treated and obtained complete response or effectiveness in the pediatric department of Ning Xia Medical University General Hospital from January 2011 to June 2017,of which 31 cases relapsed within one year and was chosen as study group.Among the other 180 cases confirmed non-relapsing within one year by phone,selected as the control group.2.Univariate statistical analysis(X~2 test,t test,rank sum test)were performed on the relevant indicators of 211children with ITP,then binary logistic regression analysis was performed on the relevant indicators with single factor significance.Results1.General conditions of relapse in children with ITP:(1)Relapse rate:31 of the 211 newly diagnosed ITP cases relapsed,with the relapse rate 14.7%;(2)The frequency of relapse:relapsing once accounted for the largest proportion(64.5%),followed by twice(19.4%)and relapsing more than 3 times accounted for the smallest proportion(6.4%);(3)First relapse time:relapsing within 1 month was most common(45.2%),followed by within 1to 3 months(32.3%)and relapsing after half a year is relatively uncommon(6.5%).2.Analysis of relapse and related risk factors in children with ITP2.1 Single factor statistical analysis2.1.1 Age of onset:The average ages of initial diagnosis were 54.36±41.42 and 38.55±33.16 months in the non-relapse group and relapse group,respectively,with a statistically significant difference between the two groups(P<0.05).2.1.2 Onset season:ITP occurs throughout the year,with the highest relapse rate in autumn(26.5%),followed by winter(17.8%)and the lowest relapse rate in spring(7.4%).Univariate statistical analysis showed that there was a correlation between the season and ITP relapse(P<0.05).2.1.3 Precede infection:The relapse rate of ITP cases with positive history of precede infection at initial diagnosis was lower than those without relevant history.The difference between the two groups was significant(P<0.05).2.1.4 Pre-treatment course:The median pre-treatment course before relapse was higher in the relapse group than that of non-relapse group.The univariate analysis showed a significant correlation between the pre-treatment course and ITP relapse(P<0.05).2.1.5 Pre-treatment platelet count:In children with relapsed ITP,the lowest pre-treatment platelet count was 1.0*10^9/L and the highest 40*10^9/L.The median pre-treatment platelet count was higher in the relapse group than that in the non-relapse group and univariate analysis showed significant difference(P<0.05).2.1.6 Platelet recovery time:The median time for the platelet to increase to effective level in the relapse group was the same as that in the non-relapse group.Univariate analysis showed a significant correlation between platelet recovery time with ITP relapse(P<0.05).2.1.7 Pre-treatment mean platelet volume(MPV)and platelet distribution width(PDW):The median pre-treatment MPV and PDW were higher in the relapse group than those in the non-relapse group.The univariate analysis showed a significant correlation between pre-treatment MPV,PDW and ITP(P<0.05).2.2 Multivariate statistical analysis:The binary logistic regression analysis showed that no significant difference existed in the onset age,pre-treatment platelet count,pre-treatment MPV and PDW,as well as seasonal were not(P>0.05),while precede infection,pre-treatment course,platelet recovery time had statistically significant difference(P<0.05).Conclusion1.The relapse rate in children with ITP is 14.7%.Relapsing once is most common(64.5%),followed by twice(19.4%)and relapsing more than 3 times accounted for the smallest proportion(6.4%);2.The first relapse occurs most often within1 month(45.2%),followed by within 1 to 3months(32.3%)and relapsing after half a year is relatively uncommon(6.5%);3.In the course of treatment for children with ITP,while precede infection,pre-treatment course,platelet recovery time were risk factors for relapse.There was no significant correlation between onset age pre-treatment platelet,pre-treatment MPV and PDW and relapse.