[Clinical Characteristics Analysis of Immune Thrombocytopenia in Children]

To analyze the clinical characteristics of immune thrombocytopenia (ITP) in children and explore the risk factors of chronic immune thrombocytopenia (CITP) .

The clinical data of children newly diagnosed with ITP in the Department of Pediatrics of the First Affiliated Hospital of Wannan Medical College from January 2015 to December 2020 were retrospectively analyzed, information on age of onset, sex, blood type, platelet count at the time of initial diagnosis, mean platelet volume, lymphocyte count, platelet-related antibodies, time to normalization of platelets, and the presence of prodromal infections. The 180 cases that met the requirements were selected according to the inclusion and exclusion criteria, with at least 1 year of outpatient and telephone follow-up. The risk factors affecting the prognosis of the children were derived by univariate and muitivariate binary logistic regression analysis, and the predictive value of the risk factors was evaluated by the receiver operating characteristic curve.

A total of 180 children with ITP were collected in this study, including 36 cases of chronic ITP (20%) and 144 cases of nonchronic ITP (80%). The results of univariate analysis showed that the age≥3 years, lymphocyte count≥（3.98±2.26）×10⁹/L, and time to normalization of platelets≥（4.38±1.79）d at the time of initial diagnosis were adverse prognostic factors of CITP. The results of muitivariate analysis showed that the children with ITP aged ≥3 years (OR=3.792, 95%CI: 1.427-10.075, P=0.008), children with longer time to normalization of platelets (OR=1.295, 95%CI: 1.055-1.591, P=0.014) were more likely to develop CITP. The results of the receiver operating characteristic curve showed that the area under the curve for age prediction of CITP was 0.715, with a sensitivity of 80.6% and specificity of 61.1%; when the platelet return to normal was 4.5 days. The maximum area under the ROC curve was 0.708, with a sensitivity of 75% and specificity of 59.9%, both of which had good values for predicting CITP.

Age≥3 years and longer time to normalization of platelets（≥4.5 days） are risk factors for CITP and have good value in predicting CITP, while gender, blood group, platelet count at initial diagnosis, mean platelet volume, plateletrelated antibodies, and presence of antecedent infection are not significantly correlated with CITP.