Clinical and laboratory predictors of chronic immune thrombocytopenia in children: a systematic review and meta-analysis

Childhood immune thrombocytopenia (ITP) is a rare autoimmune bleeding disorder. Most children recover within 6 to 12 months, but individual course is difficult to predict. We performed a systematic review and meta-analysis to identify predictors of chronic ITP. We found 1399 articles; after critical appraisal, 54 studies were included. The following predictors of chronic ITP in children, assessed in at least 3 studies, have been identified: female gender (odds ratio [OR] 1.17, 95% confidence interval [CI] 1.04-1.31), older age at presentation (age ≥11 years; OR 2.47, 95% CI 1.94-3.15), no preceding infection or vaccination (OR 3.08, 95 CI 2.19-4.32), insidious onset (OR 11.27, 95% CI 6.27-20.27), higher platelet counts at presentation (≥20 × 10(9)/L: OR 2.15, 95% CI 1.63-2.83), presence of antinuclear antibodies (OR 2.87, 95% 1.57-5.24), and treatment with a combination of methylprednisolone and intravenous immunoglobulin (OR 2.67, 95% CI 1.44-4.96). Children with mucosal bleeding at diagnosis or treatment with intravenous immunoglobulin alone developed chronic ITP less often (OR 0.39, 95% CI 0.28-0.54 and OR 0.71, 95% CI 0.52-0.97, respectively). The protective effect of intravenous immunoglobulin is remarkable and needs confirmation in prospective randomized trials as well as future laboratory studies to elucidate the mechanism of this effec

Health-related quality of life in children with newly diagnosed immune thrombocytopenia

Despite its generally transient and benign course, childhood immune thrombocytopenia has a large impact on health-related quality of life. Recently published guidelines state that quality of life should be taken into account while making decisions on management in childhood immune thrombocytopenia. We, therefore, assessed health-related quality of life in children with newly diagnosed immune thrombocytopenia in a prospective multicenter study. One hundred and seven children aged 6 months-16 years (mean age 5.57 years) were included. We used Pediatric Quality of Life Inventory™ and Kids' ITP Tools questionnaires at diagnosis and during standardized follow-up. Scores on the Pediatric Quality of Life Inventory™ Core Scales were compared with those of healthy children. Relationships between health-related quality of life scores and treatment modality, bleeding tendency and course of the disease were examined. Kids' ITP Tools proxy reports and parent self-reports showed significant higher health-related quality of life scores in children who recovered than in children with persistent immune thrombocytopenia (at 3 months: Kids' ITP Tools parent self-report score 80.85 for recovered patients (n=69) versus 58.98 for patients with persistent disease (n=21), P <0.001). No significant differences in health-related quality of life were found between children with mild or moderate bleeding or between children who received intravenous immunoglobulin or children who were carefully observed. In conclusion, health-related quality of life of children with newly diagnosed immune thrombocytopenia is not influenced by treatment modality or bleeding severity, but only by clinical course of the disease. (Dutch Trial Register identifier: NTR TC1563

Biological stratification of clinical disease courses in childhood immune thrombocytopenia

Background In childhood immune thrombocytopenia (ITP), an autoimmune bleeding disorder, there is a need for better prediction of individual disease courses and treatment outcomes. Objective To predict the response to intravenous immunoglobulins (IVIg) and ITP disease course using genetic and immune markers. Methods Children aged younger than 7 years with newly diagnosed ITP (N = 147) from the Treatment With or Without IVIG for Kids with ITP study were included, which randomized children to an IVIg or observation group. A total of 46 variables were available: clinical characteristics, targeted genotyping, lymphocyte immune phenotyping, and platelet autoantibodies. Results In the treatment arm, 48/80 children (60%) showed a complete response (platelets ≥100 × 109/L) that lasted for at least 1 month (complete sustained response [CSR]) and 32 exhibited no or a temporary response (absence of a sustained response [ASR]). For a biological risk score, five variables were selected by regularized logistic regression that predicted ASR vs CSR: (1) hemoglobin; (2) platelet count; (3) genetic polymorphisms of Fc‐receptor (FcγR) IIc; (4) the presence of immunoglobulin G (IgG) anti‐platelet antibodies; and (5) preceding vaccination. The ASR sensitivity was 0.91 (95% confidence interval, 0.80‐1.00) and specificity was 0.67 (95% confidence interval, 0.53‐0.80). In the 67 patients of the observation arm, this biological score was also associated with recovery during 1 year of follow‐up. The addition of the biological score to a predefined clinical score further improved the discrimination of favorable ITP disease courses. Conclusions The prediction of disease courses and IVIg treatment responses in ITP is improved by using both clinical and biological stratification

Intravenous immunoglobulin versus observation in childhood immune thrombocytopenia:A randomized controlled trial

Management of children with newly diagnosed immune thrombocytopenia (ITP) consists of careful observation or immunomodulatory treatment. Observational studies suggest a lower risk of chronic ITP in children after intravenous immunoglobulin (IVIg) treatment. In this multicenter randomized trial, children aged 3 months-16 years with newly diagnosed ITP, platelet counts ≤20 × 109/L and mild to moderate bleeding were randomly assigned to receive either a single infusion of 0.8 g/kg IVIg or careful observation. Primary outcome was development of chronic ITP, at time of study initiation defined as a platelet count < 150 × 109/L after 6 months. Two hundred and six children were allocated to receive IVIg (n=102) or careful observation (n=104). Chronic ITP occurred in 18.6% in the IVIg group and in 28.9% in the observation group (relative risk [RR] 0.64; 95% confidence interval [CI] 0.38-1.08). Platelet counts < 100 × 109/L at 12 months (current definition of chronic ITP) were observed in 10% children in the IVIg group and in 12% in the observation group (RR 0.83; 95% CI 0.38-1.84). Complete response rates in the first three months were significantly higher in the IVIg group. IgG- Fc receptor IIb genetic variations were associated with early complete response in both groups. Grade 4-5 bleeding occurred in 9% in the observation group versus 1% in the IVIg group. IVIg treatment at diagnosis in children with ITP did not result in a lower rate of chronic ITP. In the IVIg group higher early complete response rates and less bleeding events were observed. This trial was registered at www.trialregister.nl as NTR 1563

Transient and chronic childhood immune thrombocytopenia are distinctly affected by Fc-γ receptor polymorphisms

In childhood immune thrombocytopenia (ITP), anti-platelet autoantibodies mediate platelet clearance through Fc-γ receptor (FcγR)-bearing phagocytes. In 75% to 90% of patients, the disease has a transient, self-limiting character. Here we characterized how polymorphisms of FcγR genes affect disease susceptibility, response to intravenous immunoglobulin (IVIg) treatment, and long-term recovery from childhood ITP. Genotyping of the FCGR2/3 locus was performed in 180 children with newly diagnosed ITP, 22 children with chronic ITP, and 180 healthy control children by multiplex ligation-dependent probe amplification. Children with newly diagnosed ITP were randomly assigned to a single administration of IVIg or observation, and followed for 1 year (Treatment With or Without IVIg for Kids With ITP [TIKI] trial). We defined transient ITP as a complete recovery (≥100 × 109/L) 3 months after diagnosis, including both self-limiting disease/IVIg responders and chronic ITP as absence of a complete recovery at 12 months. ITP susceptibility, as well as spontaneous recovery and response to IVIg, was associated with the genetic variants FCGR2C*ORF and FCGR2A*27W and the FCGR2B promoter variant 2B.4. These variants were overrepresented in patients with transient (N = 131), but not chronic (N = 43), disease. The presence of FCGR2C*ORF predisposed to transient ITP with an odds ratio of 4.7 (95% confidence interval, 1.9-14.3). Chronic ITP was associated with a deletion of FCGR2C/FCGR3B (copy number region 1) with an odds ratio of 6.2 (95% confidence interval, 1.8-24.7). Taken together, susceptibility to transient and chronic ITP is distinctly affected by polymorphic variants of FCGR2/3 genes. Our data suggest that genotyping of the FCGR2/3 locus may be useful for prognosis and guidance of treatment decisions in newly diagnosed childhood ITP

Transient and chronic childhood immune thrombocytopenia are distinctly affected by Fc-γ receptor polymorphisms

In childhood immune thrombocytopenia (ITP), anti-platelet autoantibodies mediate platelet clearance through Fc-γ receptor (FcγR)-bearing phagocytes. In 75% to 90% of patients, the disease has a transient, self-limiting character. Here we characterized how polymorphisms of FcγR genes affect disease susceptibility, response to intravenous immunoglobulin (IVIg) treatment, and long-term recovery from childhood ITP. Genotyping of the FCGR2/3 locus was performed in 180 children with newly diagnosed ITP, 22 children with chronic ITP, and 180 healthy control children by multiplex ligation-dependent probe amplification. Children with newly diagnosed ITP were randomly assigned to a single administration of IVIg or observation, and followed for 1 year (Treatment With or Without IVIg for Kids With ITP [TIKI] trial). We defined transient ITP as a complete recovery (≥100 × 109/L) 3 months after diagnosis, including both self-limiting disease/IVIg responders and chronic ITP as absence of a complete recovery at 12 months. ITP susceptibility, as well as spontaneous recovery and response to IVIg, was associated with the genetic variants FCGR2C*ORF and FCGR2A*27W and the FCGR2B promoter variant 2B.4. These variants were overrepresented in patients with transient (N = 131), but not chronic (N = 43), disease. The presence of FCGR2C*ORF predisposed to transient ITP with an odds ratio of 4.7 (95% confidence interval, 1.9-14.3). Chronic ITP was associated with a deletion of FCGR2C/FCGR3B (copy number region 1) with an odds ratio of 6.2 (95% confidence interval, 1.8-24.7). Taken together, susceptibility to transient and chronic ITP is distinctly affected by polymorphic variants of FCGR2/3 genes. Our data suggest that genotyping of the FCGR2/3 locus may be useful for prognosis and guidance of treatment decisions in newly diagnosed childhood ITP