Re-evaluate the Prognostic Value of Absolute Lymphocyte Count in Pediatric Immune Thrombocytopenia

To re-evaluate the prognostic value of absolute lymphocyte count (ALC) in pediatric immune thrombocytopenia (ITP) from the perspective of age. A total of 242 ITP pediatric patients, including 141 newly diagnosed ITP (nITP), 89 chronic ITP (cITP), and 12 persistent ITP, were retrospectively reviewed for this study. These patients were divided into 3 groups according to age (group 1, ≤24 m; group 2, 24-72 m; and group 3, >72 m). The ALC detected at admission was significantly different between nITP and cITP patients without considering their age difference (5.22 vs. 3.55×10 9 /L, P <0.001). However, no significant difference was discovered after age stratification (≤24 m: 6.52 vs. 5.34×10 9 /L, P =0.161; 24-72 m: 3.78 vs. 3.63×10 9 /L, P =0.748; > 72 m: 2.53 vs. 2.40×10 9 /L, P =0.748). ROC analysis showed that the prognostic value of ALC in ITP children was limited (area under curve (AUC): ≤24 m, 24-72 m, and >72 m were 0.591, 0.570, and 0.542, respectively). Analysis of covariance showed there was no significant difference in ALC between nITP and cITP when considering age as a covariate ( P =0.131). Instead, the ROC showing that platelet to lymphocyte ratio (PLR) has prognostic value in pediatric ITP independent of age stratification (≤24 m: AUC, 0.688; 24-72 m: AUC, 0.741; >72 m: AUC, 0.680). In conclusion, there was no significant difference of ALC between nITP and cITP patients when stratified by different age groups, and PLR may be an optional prognostic indicator for ITP.