A clinical prediction score for transient versus persistent childhood immune thrombocytopenia

Abstract

There is a need for improved tools to predict persistent and chronic immune thrombocytopenia (ITP). We developed and validated a clinical prediction model for recovery from newly diagnosed ITP. The Childhood ITP Recovery Score predicts transient vs. persistent ITP and response to intravenous immunoglobulins. The score may serve as a useful tool for clinicians to individualize patient care. Abstract BackgroundChildhood immune thrombocytopenia (ITP) is an autoimmune bleeding disorder. The prognosis (transient, persistent, or chronic ITP) remains difficult to predict. The morbidity is most pronounced in children with persistent and chronic ITP. Clinical characteristics are associated with ITP outcomes, but there are no validated multivariate prediction models. ObjectiveDevelopment and external validatation of the Childhood ITP Recovery Score to predict transient versus persistent ITP in children with newly diagnosed ITP. MethodsPatients with a diagnosis platelet count ≤ 20 × 109/L and age below 16 years were included from two prospective multicenter studies (NOPHO ITP study, N = 377 [development cohort]; TIKI trial, N = 194 [external validation]). The primary outcome was transient ITP (complete recovery with platelets ≥100 × 109/L 3 months after diagnosis) versus persistent ITP. Age, sex, mucosal bleeding, preceding infection/vaccination, insidious onset, and diagnosis platelet count were used as predictors. ResultsIn external validation, the score predicted transient versus persistent ITP at 3 months follow‐up with an area under the receiver operating characteristic curve of 0.71. In patients predicted to have a high chance of recovery, we observed 85%, 90%, and 95% recovered 3, 6, and 12 months after the diagnosis. For patients predicted to have a low chance of recovery, this was 32%, 46%, and 71%. The score also predicted cessation of bleeding symptoms and the response to intravenous immunoglobulins (IVIg). ConclusionThe Childhood ITP Recovery Score predicts prognosis and may be useful to individualize clinical management. In future research, the additional predictive value of biomarkers can be compared to this score. A risk calculator is available (http://www.itprecoveryscore.org).

The Use of Clinical Scores in the Management of Immune Thrombocytopenic Purpura in Children

“…Schmidt et al ( 25 ) created a prognostic tool aiming to predict transient vs. persistent ITP in childhood. The results from the NOPHO (Nordic Pediatric Hematology—Oncology) ITP study were used to develop the score, which was then prospectively validated in the TIKI cohort (Treatment With or Without Intravenous Immunoglobulins in Kids).…”

“…Thus, the Nordic score (NOPHO) included age <10 years old, male gender, platelet count <5 × 10 9 /L, history of infection, abrupt onset, wet purpura and demonstrated prediction for short duration of ITP. Modified versions of this score have been used by Donato et al ( 19 ), Schmidt et al, ( 25 ) (Childhood ITP recovery score) and Revel-Vilk et al ( 20 ). Donato modified the platelet threshold from <5 × 10 9 /L from Nordic score, into <10 × 10 9 /L and performed separate prediction in three age groups, thus demonstrating a more accurate prediction of development of acute ITP in patients older than 1 year.…”

“…Childhood ITP recovery score ( 25 ), has demonstrated its score accuracy from the inclusion of two continuous variables (age and level of thrombocytopenia), which could correctly predict transient vs. persistent ITP. In this score, the absence of a subtle onset is the strongest predictor for transient ITP.…”

Prediction of the clinical course of immune thrombocytopenia in children by platelet kinetics

“…Early prediction of prolonged ITP was already reported in previous works. Notably, demographic (age, sex), clinical (disease onset, preceding infection or vaccination), or biological (platelet counts at diagnosis) were already reported to be not only associated with (11), but also predictive of prolonged disease (13). Besides, previous publications used linear regression to describe platelet count evolution over time but reported conflicting results, this evolution being related (14) or not (15) with disease evolution.…”

“…At diagnosis, low thrombocytopenia (> 20x10 9 /L) is also associated with a risk of chronic ITP (11), whereas stronger thrombocytopenia (< 5x10 9 /L) is associated with a low risk of chronicity (12). Further, Schmidt et al developed a score which gathered these factors into a recovery score displaying good performance to predict a prolonged disease for a given patient (13). However, their model does not account for platelet evolution over time.…”