Physician decision making in selection of second-line treatments in immune thrombocytopenia in children

Can low-dose intravenous immunoglobulin be an alternative to high-dose intravenous immunoglobulin in the treatment of children with newly diagnosed immune thrombocytopenia: a systematic review and meta-analysis

Intravenous immunoglobulin (IVIg) is a first-line treatment for children with newly diagnosed immune thrombocytopenia (ITP). Higher doses of IVIg are associated with a more insupportable financial burden to pediatric patients' families and may produce more adverse reactions. Whether low-dose IVIg (LD-IVIg) can replace high-dose IVIg (HD-IVIg) has yet to be established. We conducted a comprehensive literature search from the establishment of the database to May 1, 2023, and eventually included 22 RCTs and 3 cohort studies compared different dosages of IVIg. A total of 1989 patients were included, with 991 patients in the LD-IVIg group and 998 patients in the HD-IVIg group. Our results showed no significant differences between the two groups in the effective rate (LD-IVIg: 91% vs. HD-IVIg: 93%; RR: 0.99; 95%CI: 0.96-1.02) and the durable remission rate (LD-IVIg: 65% vs. HD-IVIg: 67%; RR: 0.97; 95%CI: 0.89-1.07). Similar results were also found in the time of platelet counts (PC) starting to rise (MD: 0.01, 95%CI: -0.06-0.09), rising to normal (MD: 0.16, 95%CI: -0.03-0.35), and achieving hemostasis (MD: 0.11, 95%CI: -0.02-0.23) between the two groups. Subgroup analysis showed the effective rate of 0.6 g/kg was equal to 1 g/kg subgroup (91%) but higher than 0.8 g/kg subgroup (82%), and a combination with glucocorticoid may contribute to effect enhancement (combined with glucocorticoid: 91% vs. IVIg alone: 86%) whether combined with dexamethasone (92%) or methylprednisolone (91%). Besides, the incidence rate of adverse reactions in the LD-IVIg group (3%) was significantly lower than the HD-IVIg group (6%) (RR: 0.61; 95%CI: 0.38-0.98). So low-dose IVIg (≤ 1 g/kg) is effective, safe, and economical, which can replace high-dose IVIg (2 g/kg) as an initial treatment. This systematic review was registered in PROSPERO (CRD42022384604).

[Expression of thyroglobulin antibody and thyroid peroxidase antibody in children with immune thrombocytopenia]

OBJECTIVES

To examine the expression of serum thyroglobulin antibody (TGAb) and thyroid peroxidase antibody (TPOAb) in children with immune thrombocytopenia (ITP).

METHODS

A total of 120 children with ITP who were admitted from October 2019 to October 2021 were enrolled as the ITP group. A total of 60 children without ITP were enrolled as the non-ITP group. According to the clinical classification of ITP, the children in the ITP group were further divided into a newly diagnosed ITP group, a persistent ITP group, and a chronic ITP group. The clinical data were compared between the ITP group and the non-ITP group and between the children with different clinical classifications of ITP. The expression levels of serum TGAb and TPOAb in children with ITP were measured and their association with the clinical classification of ITP was analyzed.

RESULTS

Compared with the non-ITP group, the ITP group had significantly lower levels of CD3+, CD4+, and platelet count (PLT) and significantly higher levels of CD8+, TGAb, and TPOAb (P<0.05). The children with chronic ITP had significantly lower levels of CD3+, CD4+, and PLT and significantly higher levels of CD8+, TGAb, and TPOAb than those with newly diagnosed ITP or persistent ITP (P<0.05). The logistic regression analysis showed that CD3+, CD4+, CD8+, TGAb, and TPOAb were the influencing factors for chronic ITP (P<0.05). A decision curve was plotted, and the results showed that TGAb combined with TPOAb within the high-risk threshold range of 0.0-1.0 had a net benefit rate of >0 in evaluating the clinical classification of ITP in children.

CONCLUSIONS

TGAb and TPOAb are abnormally expressed in children with ITP and are associated with the clinical classification of ITP in children.

Thrombopoietin receptor agonists and rituximab for treatment of pediatric immune thrombocytopenia: A systematic review and meta-analysis of prospective clinical trials

BACKGROUND

Children with immune thrombocytopenia (ITP) may require second-line ITP therapies. The high remission rate in pediatric patients, need for extended-duration use of thrombopoietin receptor agonists (TPO-RAs), drug adherence, potential side effects, monitoring, and cost effectiveness are factors that should be considered in decision-making about second-line therapies. Rituximab (RTX) has been used off-label for years to treat ITP but there are limited studies about its efficacy and safety in children. To date, no studies have directly compared TPO-RAs with RTX for the treatment of childhood ITP.

METHODS

This systematic review analyzed the overall platelet response, durability of treatment effect, and safety for RTX use in comparison to TPO-RAs in pediatric ITP. MEDLINE/PubMed, EMBASE, Cochrane Library, and Web of Science databases were searched through December 2020 and meta-analysis was conducted using proportions of success/failure for each intervention in the selected studies.

RESULTS

The proportion of participants achieving the primary endpoint of a platelet response above 50,000 was similar for TPO-RAs (proportion = 0.71, 95% CI: 0.63-0.78) and RTX (proportion = 0.68, 95% CI: 0.53-0.82). However, considerable variation was found between the two groups with regards to the sustainability of the response and other secondary outcomes such as need for rescue and adverse events. RTX was associated with higher rates of rescue therapy.

CONCLUSIONS

In this analysis of prospective pediatric ITP studies, RTX and TPO-RAs had similar rates of overall platelet response but differed in other important measures. Prospective comparative studies are needed to better characterize second-line treatments for pediatric ITP.

Psychometric Evaluation of ITP Life Quality Index (ILQI) in a Global Survey of Patients with Immune Thrombocytopenia

INTRODUCTION

Immune thrombocytopenia (ITP) is an autoimmune disorder caused by immunologic destruction of otherwise normal platelets. Patients and physicians differ in their views pertaining to the limitations imposed on patients' daily lives by ITP and its treatment. Poor understanding of ITP symptoms can result in misdiagnosis and complex treatment patterns, and affect patient health-related quality of life (HRQoL). The ITP Life Quality Index (ILQI) is a 10-item patient-reported outcome measure developed for clinical practice to aid discussions between patients and physicians. This research aimed to validate the psychometric properties of the ILQI using data collected in the ITP World Impact Survey (I-WISh).

METHODS

I-WISh data containing responses to the ILQI from 1507 patients with ITP across 13 countries worldwide was subject to psychometric analysis to evaluate the structure, reliability and validity of the ILQI and assess scoring cut-offs.

RESULTS

The ILQI has an overarching unidimensional structure, supporting a total score including all 10 items. Reliability was supported (Cronbach's alpha = 0.90). ILQI scores monotonically increased with ITP severity. ILQI scores correlated with measures of fatigue and emotional well-being, supporting construct validity. Differential item functioning (DIF) analyses showed that ILQI item responses were interpreted similarly between the USA and other Western countries. It was suggested that previous clinical cut-off score of 20 for "impaired HRQoL" was reduced to 17 and a cut-off of 23-25 (rather than 30) was suggested to assess "significantly impaired HRQoL".

CONCLUSION

The validity and reliability of the ILQI to assess HRQoL of patients with ITP is supported. The revised cut-off scores for the ILQI will aid patient-centric decision-making.

An Update on Pediatric Immune Thrombocytopenia (ITP): Differentiating Primary ITP, IPD, and PID

Immune thrombocytopenia (ITP) is the most common acquired thrombocytopenia in children and is caused by both immune-mediated decreased platelet production and increased platelet destruction. In the absence of a diagnostic test, ITP must be differentiated from other thrombocytopenic disorders, including inherited platelet disorders (IPD). In addition, a diagnosis of secondary ITP due to a primary immune deficiency (PID) with immune dysregulation may not be apparent at diagnosis but can alter management and should be considered in an expanding number of clinical scenarios. The diagnostic evaluation of children with thrombocytopenia will vary based on the clinical history and laboratory features. Access to genotyping has broadened the ability to specify the etiology of thrombocytopenia, while increasing access to immunophenotyping, functional immunologic and platelet assays, and biochemical markers has allowed for more in-depth evaluation of patients. With this greater availability of testing, diagnostic algorithms in patients with thrombocytopenia have become complex. In this article, we highlight the diagnostic evaluation of thrombocytopenia in children with a focus on ITP, including consideration of underlying genetic and immune disorders, and utilize hypothetical patient cases to describe disease manifestations and strategies for treatment of pediatric ITP.

Romiplostim in children with newly diagnosed or persistent primary immune thrombocytopenia

Immune thrombocytopenia (ITP) is a disease of heterogenous origin characterized by low platelet counts and an increased bleeding tendency. Three disease phases have been described: newly diagnosed (≤ 3 months after diagnosis), persistent (> 3-12 months after diagnosis), and chronic (> 12 months after diagnosis). The majority of children with ITP have short-lived disease and will not need treatment. For children with newly diagnosed ITP, who have increased bleeding symptoms, short courses of steroids are recommended. In children who do not respond to first-line treatment or who become steroid dependent, thrombopoietin receptor agonists (TPO-RAs) are recommended because of their efficacy and safety profiles. In this narrative review, we evaluate the available evidence on the use of the TPO-RA romiplostim to treat children with newly diagnosed or persistent ITP and identify data from five clinical trials, five real-world studies, and a case report. While the data are more limited for children with newly diagnosed ITP than for persistent ITP, the collective body of evidence suggests that romiplostim is efficacious in increasing platelet counts in children with newly diagnosed or persistent ITP and may result in long-lasting treatment-free responses in some patients. Furthermore, romiplostim was found to be well tolerated in the identified studies. Collectively, the data suggest that earlier treatment with romiplostim may help children to avoid the side effects associated with corticosteroid use and reduce the need for subsequent treatment.

Phase 3 randomised trial of eltrombopag versus standard first-line pharmacological management for newly diagnosed immune thrombocytopaenia (ITP) in children: study protocol

INTRODUCTION

Immune thrombocytopaenia (ITP) is an acquired disorder of low platelets and risk of bleeding. Although many children can be observed until spontaneous remission, others require treatment due to bleeding or impact on health-related quality of life. Standard first-line therapies for those who need intervention include corticosteroids, intravenous immunoglobulin and anti-D globulin, though response to these agents may be only transient. Eltrombopag is an oral thrombopoietin receptor agonist approved for children with chronic ITP who have had an insufficient response to corticosteroids, intravenous immunoglobulin or splenectomy. This protocol paper describes an ongoing open-label, randomised trial comparing eltrombopag to standard first-line management in children with newly diagnosed ITP.

METHODS AND ANALYSIS

Randomised treatment assignment is 2:1 for eltrombopag versus standard first-line management and is stratified by age and by prior treatment. The primary endpoint of the study is platelet response, defined as ≥3 of 4 weeks with platelets >50×109/L during weeks 6-12 of therapy. Secondary outcomes include number of rescue therapies needed during the first 12 weeks, proportion of patients who do not need ongoing treatment at 12 weeks and 6 months, proportion of patients with a treatment response at 1 year, and number of second-line therapies used in weeks 13-52, as well as changes in regulatory T cells, iron studies, bleeding, health-related quality of life and fatigue. A planned sample size of up to 162 randomised paediatric patients will be enrolled over 2 years at 20 sites.

ETHICS AND DISSEMINATION

The study has been approved by the centralised Baylor University Institutional Review Board. The results are expected to be published in 2023.

TRIAL REGISTRATION NUMBER

NCT03939637.

Response to rituximab in children and adults with immune thrombocytopenia (ITP)

BACKGROUND

Rituximab is a monoclonal anti-CD20 antibody used as a second-line treatment for immune thrombocytopenia (ITP). As additional treatments for ITP emerge, identifying the most appropriate patients and optimal timing for rituximab are important but challenging without established predictors of response to therapy.

OBJECTIVES

The purpose of this study was to describe demographic, clinical, and laboratory characteristics of pediatric and adult patients with ITP to identify differences in evaluation before rituximab administration and correlates of platelet response.

METHODS

This is a retrospective cohort study describing the characteristics of patients with ITP treated with rituximab from 2010 to 2020 at two academic tertiary care centers.

RESULTS

A total of 64 patients met criteria for inclusion. Complete rituximab response (56%) was not significantly different between children (58%, n = 24) and adults (55%, n = 40). Response rate was similar in those with primary versus secondary ITP (53% vs 62%). Among patients treated with rituximab, Evans Syndrome was more common in children than adults (42% vs 18%). Immunologic labs assessed before rituximab varied by age and were more commonly evaluated in children (lymphocyte subsets 88% vs 22%). Immunologic markers, including antinuclear antibody, direct antiglobulin testing, immunoglobulin levels, and lymphocyte subsets, did not predict response to rituximab in pediatric or adult patients with ITP.

CONCLUSIONS

Pre-rituximab immunologic evaluation varied significantly between adults and children, which could represent institution-specific practice patterns or a more general practice difference. If the latter, underlying immunodeficiency in adults with ITP may be underrecognized. Standardized guidance for pre-rituximab immunologic evaluation is needed.

Quality of life is an important indication for second-line treatment in children with immune thrombocytopenia

BACKGROUND

The decision to initiate second-line treatment in children with immune thrombocytopenia (ITP) is complex and involves many different factors.

METHODS

In this prospective, observational, longitudinal cohort study of 120 children from 21 centers, the factors contributing to the decision to start second-line treatments for ITP were captured. At study entry, clinicians were given a curated list of 12 potential reasons the patient required a second-line treatment. Clinicians selected all that applied and ranked the top three reasons.

RESULTS

Quality of life (QOL) was the most frequently cited reason for starting a second-line therapy. Clinicians chose it as a reason to treat in 88/120 (73%) patients, as among the top three reasons in 68/120 (57%), and as the top reason in 32/120 (27%). Additional factors ranked as the top reason to start second-line treatment included severity of bleeding (22/120, 18%), frequency of bleeding (19/120, 16%), and severity of thrombocytopenia (18/120, 15%). Patients for whom QOL (p = .006) or sports participation (p = .02) were ranked reasons were more likely to have chronic ITP, whereas those for whom severity (p = .003) or frequency (p = .005) of bleeding were ranked reasons were more likely to have newly diagnosed or persistent ITP. Parental anxiety, though rarely the primary impetus for treatment, was frequently cited (70/120, 58%) as a contributing factor.

CONCLUSION

Perceived QOL is the most frequently selected reason pediatric patients start second-line therapies for ITP. It is critical that studies of treatments for childhood ITP include assessments of their effects on QOL.

Severe Immune Thrombocytopenia Following MMR Vaccination with Rapid Recovery: A Case Report and Review of Literature

Immune thrombocytopenia (ITP) is an autoimmune disease that occurs following viral illnesses and may also infrequently occur after measles, mumps, and rubella (MMR) vaccination. ITP typically presents with the sudden appearance of a petechial rash, bruising, and/or bleeding in an otherwise healthy-appearing child. However, ITP following MMR vaccine does not commonly cause severely depleted platelets. We report a case of ITP after MMR vaccination in a 13-month-old baby boy, who presented with petechial rash all over his body. The child had severe thrombocytopenia but was successfully treated with a single dose of intravenous immunoglobulin without complications. The study highlights that ITP post-MMR vaccine is an easily treatable condition.

Second-line treatments and outcomes for immune thrombocytopenia: A retrospective study with electronic health records

BACKGROUND

Second-line treatment for immune thrombocytopenia (ITP) is not well reported for patients treated in real-world clinical settings.

OBJECTIVE

The purpose of this study was to compare outcomes of four second-line treatments for ITP.

PATIENTS/METHODS

Included adult patients had at least two medical records containing ITP diagnoses and second-line eltrombopag, romiplostim, rituximab, or splenectomy. Date of treatment initiation or splenectomy was set as index date, between July 1, 2008, and March 31, 2017. Patients had first-line corticosteroid or intravenous immune globulin treatment and continuous database activity from 6 months before to 12 months after index. Patient characteristics, treatment patterns, platelet counts, bleeding-related episodes (BREs), and thrombotic events (TEs) were compared by second-line treatment cohort.

RESULTS

The sample included 3332 patients (mean age, 60.5 years; 52.3% female): eltrombopag (5.8%), romiplostim (9.9%), rituximab (73.3%), and splenectomy (11.0%). Patients having splenectomy were younger, more likely female and commercially insured, and less likely to require a third line of treatment than medical regimen cohorts. Proportions of patients having treatment-free (≥180 days with no second-line index or rescue agent) periods varied significantly (P = .01) by regimen: 33% for eltrombopag, 23% for romiplostim, 26% for rituximab, and 17% for splenectomy. All regimens significantly improved platelet counts, while TE and BRE rates differed significantly (P = .03 and P = .01, respectively) when all treatment groups were compared.

CONCLUSIONS

Over an average 7-year follow-up, all second-line regimens improved platelet counts, but eltrombopag yielded the highest proportion of patients with completely treatment-free periods of at least 180 days.

Fatigue in children and adolescents with immune thrombocytopenia

Immune thrombocytopenia (ITP), an acquired autoimmune disorder of low platelets and risk of bleeding, has a substantial impact on health-related quality of life (HRQoL). Patients with ITP often report significant fatigue, although the pathophysiology of this is poorly understood. In this observational cohort of 120 children receiving second-line therapies for ITP, we assessed reports of fatigue using the Hockenberry Fatigue Scale. Children and adolescents with ITP reported a similarly high level of fatigue with 54% (29/54) of children and 62% (26/42) of adolescents reporting moderate-to-severe fatigue. There was no correlation between fatigue and age or gender. Adolescents with newly diagnosed and persistent ITP had higher mean fatigue scores than those with chronic ITP (P = 0·03). Fatigue significantly improved in children and adolescents by 1 month after starting second-line treatments, and this improvement continued to be present at 12 months after starting treatment. Fatigue scores at all time-points correlated with general HRQoL using the Kids ITP Tool, but did not correlate with bleeding symptoms, platelet count, or platelet response to treatment. Fatigue is common in children and adolescents with ITP and may benefit from ITP-directed treatment even in the absence of bleeding symptoms.

The role of romiplostim for pediatric patients with immune thrombocytopenia

The thrombopoietin receptor agonists (TPO-RAs) are a class of platelet growth factors used to treat immune thrombocytopenia (ITP) in children and adults. Romiplostim is a peptide TPO-RA approved for over a decade to treat adults with ITP but was just recently US Food and Drug Administration approved to manage ITP in children 1 year of age and older who have had an inadequate response to corticosteroids, intravenous immunoglobulin, or splenectomy. Like the small molecule TPO-RA eltrombopag, romiplostim offers a high clinical response rate in pediatric patients with ITP, but requires use over an extended, and possibly indefinite, duration. This review is a critical appraisal of the role of romiplostim in pediatric ITP, discussing the safety and efficacy of this agent in clinical trials of children and adults and defining the patients most likely to benefit from romiplostim treatment. The treating hematologist is additionally provided guidance with treatment goals, dosing strategies, toxicity management, and indications for discontinuation.

Second-line treatment trends and long-term outcomes of 392 children with chronic immune thrombocytopenic purpura: the French experience over the past 25 years

Childhood chronic immune thrombocytopenic purpura (cITP) is a rare disease. In severe cases, there is no evidence for the optimal therapeutic strategy. Our aim was to describe the real-life management of non-selected children with cITP at diagnosis. Since 2004, patients less than 18 years old with cITP have been enrolled in the national prospective cohort, OBS'CEREVANCE. From 1990 to 2014, in 29 centres, 392 children were diagnosed with cITP. With a median follow-up of six years (2·0-25), 45% did not need second-line therapy, and 55% (n = 217) received one or more second lines, mainly splenectomy (n = 108), hydroxychloroquine (n = 61), rituximab (n = 61) or azathioprine (n = 40). The overall five-year further second-line treatment-free survival was 56% [95% CI 49·5-64.1]. The use of splenectomy significantly decreased over time. Hydroxychloroquine was administered to children with positive antinuclear antibodies, more frequently older and girls, and reached 55% efficacy. None of the patients died. Ten years after the initial diagnosis, 55% of the 56 followed children had achieved complete remission. Children with cITP do not need second-line treatments in 45% of cases. Basing the treatment decision on the pathophysiological pathways is challenging, as illustrated by ITP patients with positive antinuclear antibodies treated with hydroxychloroquine.

Romiplostim for the Treatment of Immune Thrombocytopenia: Spotlight on Patient Acceptability and Ease of Use

Immune thrombocytopenia (ITP) is an immune-mediated disorder resulting in platelet destruction and subsequent thrombocytopenia. Bleeding symptoms range from mild cutaneous bleeding to life-threatening hemorrhage. Romiplostim, a peptide-antibody fusion product, is a thrombopoietin receptor agonist (TPO-RA) indicated for use in patients with ITP. Romiplostim is US Food and Drug Administration (FDA) approved in children ≥1 year of age with ITP of >6 months' duration who have had an inadequate response to first-line therapies or splenectomy. FDA approval in adults with chronic ITP was expanded in October 2019 to include adults with newly diagnosed (<3 months' duration) and persistent (3-12 months' duration) ITP who demonstrated an inadequate response to first-line therapies, including corticosteroids and immunoglobulins, or splenectomy. The newly published 2019 American Society of Hematology ITP Guidelines place TPO-RAs, including romiplostim, as second-line therapies in both children and adults. Here, we review the use of romiplostim as second-line therapy with a spotlight on health-related quality of life, ease of use, and patient preference.

Second-line treatments in children with immune thrombocytopenia: Effect on platelet count and patient-centered outcomes

Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder with isolated thrombocytopenia and hemorrhagic risk. While many children with ITP can be safely observed, treatments are often needed for various reasons, including to decrease bleeding, or to improve health related quality of life (HRQoL). There are a number of available second-line treatments, including rituximab, thrombopoietin-receptor agonists, oral immunosuppressive agents, and splenectomy, but data comparing treatment outcomes are lacking. ICON1 is a prospective, multi-center, observational study of 120 children starting second-line treatments for ITP designed to compare treatment outcomes including platelet count, bleeding, and HRQoL utilizing the Kids ITP Tool (KIT). While all treatments resulted in increased platelet counts, romiplostim had the most pronounced effect at 6 months (P = .04). Only patients on romiplostim and rituximab had a significant reduction in both skin-related (84% to 48%, P = .01 and 81% to 43%, P = .004) and non-skin-related bleeding symptoms (58% to 14%, P = .0001 and 54% to 17%, P = .0006) after 1 month of treatment. HRQoL significantly improved on all treatments. However, only patients treated with eltrombopag had a median improvement in KIT scores at 1 month that met the minimal important difference (MID). Bleeding, platelet count, and HRQoL improved in each treatment group, but the extent and timing of the effect varied among treatments. These results are hypothesis generating and help to improve our understanding of the effect of each treatment on specific patient outcomes. Combined with future randomized trials, these findings will help clinicians select the optimal second-line treatment for an individual child with ITP.

Association of a positive direct antiglobulin test with chronic immune thrombocytopenia and use of second line therapies in children: A multi-institutional review

Immune thrombocytopenia (ITP) is the most common autoimmune cytopenia in children. Approximately, 25% of patients develop chronic disease, which may be unpredictable and challenging to treat. It is not currently possible to predict at the time of presentation which patients will have chronic disease or will experience symptoms requiring second-line therapy defined as treatment beyond corticosteroids, intravenous immunoglobulin, or Rh immune globulin. A multi-institutional retrospective review of 311 pediatric patients with ITP was performed with the goal of identifying clinical characteristics associated with disease course. In a cohort of 216 patients tested and for whom disease status was known, a positive direct antiglobulin test (DAT) was associated with chronic ITP vs spontaneous resolution of disease (29.2% vs 8.1%, P < 0.001) as well as the need for treatment with second line agents (38.5% vs 11.4%, P < 0.001) in 241 patients. Controlling for the effect of Evans syndrome, defined as having two immune cytopenias, a positive DAT was independently associated with chronic ITP (OR = 2.7, 95% CI: 1.0-7.2, P = 0.041) and use of second-line agents (OR: 3.6, 95% CI: 1.7-7.7, P = 0.001) by multivariate logistic regression model. These findings demonstrate an association with positive DAT and chronic disease, as well as refractory disease requiring second-line agents.

Primary and Secondary Immune Cytopenias: Evaluation and Treatment Approach in Children

This review summarizes the evaluation and management of the autoimmune cytopenias, a heterogeneous group of conditions including, but not limited to, autoimmune hemolytic anemia, immune thrombocytopenia, and multilineage disorders in Evans syndrome. These diseases can be challenging to treat and there are limited data comparing second-line therapeutics. The understanding of the molecular cause of these conditions is improving with the goal of advancing therapies and making them more targeted.

Platelet-specific antibodies and differences in their expression in childhood immune thrombocytopenic purpura predicts clinical progression

IMPORTANCE

Immune thrombocytopenic purpura (ITP) is the most common bleeding disorder in children. Despite the highly spontaneously remission, still almost 20% of cases progress into chronic or refractory ITP, which seriously affects children's quality of life. Currently there is no method to predict the initial stage of childhood ITP.

OBJECTIVES

To evaluate platelet-specific antibodies and compare differences in their expression in childhood ITP to predict clinical progression.

METHODS

This is a single-center prospective cohort study from April 2014 to October 2015. We enrolled children initially diagnosed as ITP. Anti-GPIIb/IIIa and GPIb/IX antibodies were assayed by enzyme-linked immunoadsorbent assay (ELISA) and patients were followed up for 1 year. We also analyzed the relationship between the expression of the platelet-specific antibodies GPIIb/IIIa and GPIb/IX and their respective clinical prognoses.

RESULTS

Overall, 134 cases were enrolled including 77 boys and 57 girls with a median age of 19 months (range: 1 to 159). Positive rates of anti-platelet antibodies were 79.8%. After a 1-year observation period, 84.3% were diagnosed as newly diagnosed ITP and 13.4% were diagnosed as chronic ITP. Patients with anti-GPIIb/IIIa antibody had a higher risk for newly diagnosed ITP compared with patients who were anti-GPIb/IX antibody positive only (93% vs 25%, P = 0.005; 87% vs 25%, P = 0.014, respectively). There were more anti-GPIb/IX antibody positive only cases, diagnosed as chronic ITP, compared with anti-GPIIb/IIIa antibody positive only cases and double GPIIb/IIIa and GPIb/IX antibody positive cases (75% vs 7%, P = 0.005; 75% vs 13%, P = 0.014, respectively). Interpretation.

INTERPRETATION

Patients with anti-GPIIb/IIIa antibody (either single or double) were predicted to have a good prognosis, whereas anti-GPIb/ IX antibody only predicted a poor prognosis. These results should be confirmed via a larger cohort multicenter study.

Fostamatinib for the treatment of adult persistent and chronic immune thrombocytopenia: Results of two phase 3, randomized, placebo-controlled trials

Spleen tyrosine kinase (Syk) signaling is central to phagocytosis-based, antibody-mediated platelet destruction in adults with immune thrombocytopenia (ITP). Fostamatinib, an oral Syk inhibitor, produced sustained on-treatment responses in a phase 2 ITP study. In two parallel, phase 3, multicenter, randomized, double-blind, placebo-controlled trials (FIT1 and FIT2), patients with persistent/chronic ITP were randomized 2:1 to fostamatinib (n = 101) or placebo (n = 49) at 100 mg BID for 24 weeks with a dose increase in nonresponders to 150 mg BID after 4 weeks. The primary endpoint was stable response (platelets ≥50 000/μL at ≥4 of 6 biweekly visits, weeks 14-24, without rescue therapy). Baseline median platelet count was 16 000/μL; median duration of ITP was 8.5 years. Stable responses occurred in 18% of patients on fostamatinib vs. 2% on placebo (P = .0003). Overall responses (defined retrospectively as ≥1 platelet count ≥50 000/μL within the first 12 weeks on treatment) occurred in 43% of patients on fostamatinib vs. 14% on placebo (P = .0006). Median time to response was 15 days (on 100 mg bid), and 83% responded within 8 weeks. The most common adverse events were diarrhea (31% on fostamatinib vs. 15% on placebo), hypertension (28% vs. 13%), nausea (19% vs. 8%), dizziness (11% vs. 8%), and ALT increase (11% vs. 0%). Most events were mild or moderate and resolved spontaneously or with medical management (antihypertensive, anti-motility agents). Fostamatinib produced clinically-meaningful responses in ITP patients including those who failed splenectomy, thrombopoietic agents, and/or rituximab. Fostamatinib is a novel ITP treatment option that targets an important mechanism of ITP pathogenesis.