Update on the Intercontinental Cooperative ITP Study Group (ICIS) and on the Pediatric and Adult Registry on Chronic ITP (PARC ITP)

The first national pediatric immune thrombocytopenia registry in Iran: research protocol and preliminary study results

BACKGROUND

Disease registries are comprehensive databases that record detailed information on patients diagnosed with specific conditions, providing valuable insights into their diagnosis, treatment, and outcomes. This study aims to describe the pilot phase of the national pediatric Immune Thrombocytopenia(ITP) registry (NPITP) in Iran, serving as the inaugural interpretive report.

METHODS

This patient-centered software system was implemented as a national program across multiple pediatric centers in Iran. Several focus groups were conducted to establish a minimum data set (MDS) comprising six main classes, 14 sub-classes, and 187 data elements. Following expert consensus on the final data set, a web-based software tool was developed by the dedicated IT team, accessible online and offline via https://disreg.sbmu.ac.ir/q/ITP.html . The registry included children aged between two months and 18 years with a platelet count below 100 × 109/L, based on predefined inclusion criteria.

RESULTS

Within a four-month period, a total of 60 ITP patients were registered, including 41 (68.3%) newly diagnosed cases, 68 (13.6%) persistent cases, and 14 (23.3%) with chronic ITP. The mean age of the registered patients was 55.93 ± 9.72 months. The most frequently observed bleeding symptoms were petechiae (68.3%), purpura (51.6%), and ecchymosis (13.3%). Among the newly diagnosed patients, 20 (33.3%) received intravenous immunoglobulin (IVIG), 17 (28.3%) were treated with prednisolone, and 17 (28.3%) received combined IVIG and steroid therapy. Of all patients, 40 (66.7%) demonstrated a complete response to treatment, while 16 (26.7%) exhibited a partial response. Four patients (6.7%) remained unresponsive to therapy. Treatment-related complications, such as Cushing's syndrome, edema, weight gain, hirsutism, and mood disorders, were reported in 10 patients (16.6%). However, the majority of patients (81.7%) did not experience therapy-related complications.

CONCLUSION

The pilot phase of the NPITP registry successfully implemented a web-based software tool for data collection, aiming to enhance the quality of care, facilitate clinical research, and support health service planning in the future.

Adolescents and young adults with newly diagnosed primary immune thrombocytopenia

Current immune thrombocytopenia (ITP) guidelines target children and adults, leading to oversimplification. Adolescents and young adults (AYAS) comprise a separate group with distinct health and psychosocial issues. This study aimed to describe the clinical presentation and therapeutic strategies of ITP among AYAS. We analyzed data from two large ITP registries (PARC-ITP; CARMEN-France) and included newly diagnosed ITP patients (aged 12-25 years) with an initial platelet counts of <100×109/L. Patients with secondary ITP or non-immune thrombocytopenia (n=57) and pregnant women (n=10) were excluded. Of the 656 cases of AYAS with primary ITP registered from 2004 up to 2021, 12-month follow-up data were available for 72%. The initial median platelet count was 12×109/L. In 109 patients (17%), the diagnosis was incidental, without documented bleeding. Apart from gynecological bleeding, the clinical and therapeutical characteristics of females and males were similar. Platelet-enhancing drugs were reported in 66%, 45%, and 30% of patients at diagnosis, 1-6 months, and 6-12 months after diagnosis, respectively. Corticosteroids were the preferred treatment at all time points. At 12 months, 50% of all patients developed chronic ITP. In the subgroup of patients with initial severe thrombocytopenia (<20×109/L), those receiving frontline treatment had a higher remission rate at 1 year than those who followed an initial watch-and-wait strategy (53% and 32%; P<0.05). Our analysis indicates that the remission rate at 1 year may be associated with the initial treatment strategy. This hypothesis must be confirmed in prospective studies.

Misdiagnosed thrombocytopenia in children and adolescents: analysis of the Pediatric and Adult Registry on Chronic ITP

Primary immune thrombocytopenia (ITP) in children is a diagnosis of exclusion, but cases of secondary ITP and nonimmune thrombocytopenia (non-IT) are generally difficult to recognize in a timely fashion. We describe a pediatric population with a revised diagnosis of secondary ITP or non-IT within 24 months of follow-up. Data were extracted from the Pediatric and Adult Registry on Chronic ITP, an international multicenter registry collecting data prospectively in patients with newly diagnosed primary ITP. Between 2004 and 2019, a total of 3974 children aged 3 months to 16 years were included. Secondary ITP and non-IT were reported in 113 patients (63 female subjects). Infectious (n = 53) and autoimmune (n = 42) diseases were identified as the main causes, with median ages at diagnosis of 3.2 years (interquartile range: 1.2; 6.7 years) and 12.4 years (interquartile range: 7.6; 13.7 years), respectively. Other causes included malignancies, aplastic anemia, immunodeficiency, and drug use. Patients with malignancy and aplastic anemia had significantly higher initial platelet counts (37 and 52 × 109/L) than did those with infection or autoimmune diseases (12 and 13 × 109/L). Characteristics of patients with secondary ITP due to infection were similar to those of children with primary ITP at first presentation, indicating similar mechanisms. Significant differences were found for age, sex, comorbidities, initial bleeding, sustained need for treatment, and disease persistence for the remaining noninfectious group compared with primary ITP. Based on our findings, we propose a diagnostic algorithm that may serve as a basis for further discussion and prospective trials.

A comparative prospective observational study of children and adults with immune thrombocytopenia: 2-year follow-up

Comparative clinical studies of children and adults with immune thrombocytopenia (ITP) are poorly covered in the literature. However, the accepted classification of ITP-childhood ITP and adult ITP-results in considerable differences in treatment protocols and practice guidelines. The analysis of the Pediatric and Adult Registry on Chronic ITP (PARC-ITP) of patients at first presentation demonstrated fewer differences in clinical and laboratory findings at initial diagnosis between children and adults than expected. The present report of 2-year follow-up data supports the hypothesis that there are common aspects of childhood and adult ITP. Data of 3360 children and 420 adults were collected during the time of 2004 until 2015 at initial diagnosis. Follow-up information was available for 51% and 33% of children and 66% and 49% of adults at 12- and 24-months, respectively. Similarities were found in unexpected areas of ITP, such as the rate of late remission at 12 and 24 months, reported bleeding sites, platelet count in bleeders, and the frequency of treated patients with persistent or chronic ITP. Differences were confirmed for the overall rate of remission and treatment modalities. Unexpected differences were found in the percentage of nonbleeders, with more adults in the nonbleeder group. More studies are needed to investigate different age groups with the aim to optimize their management.

Differential Expression of T-bet and GATA3 in Egyptian Children with Idiopathic Thrombocytopenic Purpura

GATA3 and T-box (T-bet) expressed in T-cells are transcriptional factors that play a critical role in development of Th2 and Th1 immunity respectively. GATA3 is expressed during Th2 differentiation and T-bet is expressed exclusively in Th1 cells. Thus, a balance between GATA3 and T-bet is believed to control Th2/Th1 polarization. Therefore, the high expression of T-bet and low expression of GATA3 indicate the existence of Th1 polarization in children with acute immune thrombocytopenic purpura (ITP). This might be related to the regulation of T-bet and GATA3. The objective of this work was to study the expression of transcriptional factors T-bet and GATA3 m RNA in children with idiopathic thrombocytopenic purpura and correlate it with clinical findings, laboratory findings, and outcome of patients. In this study the expression of T-bet and GATA3 genes was analysed in 20 normal healthy individuals and 40 children with ITP (20 acute and 20 persistent) using reverse transcriptase polymerase chain reaction to investigate a possible relation, association or correlation with the type of ITP and prognosis. T-bet was expressed significantly in 60 % of acute ITP children (12/20) (P value 0.001) and not expressed in persistent ITP children (0/20), while GATA3 was expressed in 25 % of persistent ITP patients (5/20) (P value 0.017) and not expressed in acute ITP patients (0/20). Both genes were not detected in healthy controls. We concluded that the high expression of T-bet and the low expression of GATA3 indicate the existence of Th1 polarization in children with acute ITP. This might be related to the regulation of T-bet and GATA3. Intensive studies of abnormal cytokine profiles in ITP have led to cytokine therapies that exploit the effects of IFN-γ on Th2 cells, but such therapies are often ineffective to develop safe and effective therapeutic tools. Targeting specific molecules such as T-bet and GATA3 may be a novel therapeutic tool in ITP.

Advances in the pathophysiology of primary immune thrombocytopenia

OBJECTIVES

Classically, immune thrombocytopenia (ITP) was thought to be caused by the destruction and insufficient production of platelets, as mediated by autoantibodies. More recently other immune mechanisms that contribute to the disease have been discovered. This review attempts to address the main unresolved questions in ITP.

METHODS

We review the most current knowledge of the pathophysiology of ITP. Immunological effects of available therapies are also described.

DISCUSSION

The trigger may be a loss of tolerance due to molecular mimicry with cross-reaction of antibodies arising from infectious agents or drugs, genetic factors, and/or platelet Toll receptors. This loss of tolerance activates autoreactive effector B and T lymphocytes, which in turn initiates platelet destruction, mediated by cytotoxic T lymphocytes and the release of pro-inflammatory cytokines (IL-2/IL-17) by T helper (Th) cells (Th1/Th17). Th2 (anti-inflammatory) and regulatory B (Breg) and Treg cells are also inhibited (with decrease in IL-10/TGF-β), which leads to the disease becoming chronic. Some isotypes of autoantibodies may increase the bleeding risk. Corticosteroids, rituximab, and thrombopoietin receptor agonists (A-TPOs) all increase levels of Tregs and TGF-β. The A-TPOs also increase Breg levels, which could explain why complete remission has been seen in some cases.

CONCLUSION

A better understanding of the immunomodulatory effects of each ITP therapy is needed to best manage the disease.

Correlation of Notch1/Hes1 Genes Expression Levels in Egyptian Paediatric Patients with Newly Diagnosed and Persistent Primary Immune(Idiopathic) Thrombocytopenic Purpura

Notch signalling is involved in the development of several autoimmune diseases, one of such diseases is ITP. The aim of this study was to investigate and compare the expression levels of Notch1 receptor and its target Hes1 gene in Egyptian paediatric ITP patients. Real-time quantitative reverse transcriptase polymerase chain reaction was used to analyse the expression levels of Notch1 and Hes1 in 42 children with primary ITP (22 newly diagnosed and 20 persistent) cases. Twenty age and sex matched non-ITP controls were included. The expression levels of Notch1 were higher in newly diagnosed and persistent cases than controls with high statistical significant difference (P value < 0.001, P < 0.001) respectively, similarly as regards the expression levels of HES1 (P value < 0.001, P < 0.007) respectively. A significant positive correlation was found between Notch1 and Hes1 expression levels in newly diagnosed cases (r = 0.587, P value = 0.004). There was an association between levels of both genes in most of ITP patients but Hes1 was markedly elevated than Notch1 in few cases. High expression levels of Notch1/Hes1 indicated the important role of Notch signalling in both newly diagnosed and persistent ITP. High expression levels of Hes1 than Notch1 may shed light on its value as a therapeutic target for future research in ITP.

Pulmonary Endarterectomy in a Patient with Immune Thrombocytopenic Purpura

Immune thrombocytopenic purpura (ITP) patients are at high risk for bleeding complications regarding surgeries involving cardiopulmonary bypass. We report an ITP patient with chronic thromboembolic pulmonary hypertension who underwent uncomplicated pulmonary endarterectomy with receiving postoperative intravenous immunoglobulin (IVIG) therapy. The positive outcome of this case may suggest that pulmonary endarterectomy surgery is performed safely for ITP patients.

The role of IL-23/Th17 pathway in patients with primary immune thrombocytopenia

Background

Primary immune thrombocytopenia (ITP) is an autoimmune bleeding disorder with an unclear etiology. This study aims to investigate the role of IL-23/Th17 pathway in patients with ITP.

Method

The gene expressions of IL-17, IL-23 and their receptors in ITP patients and healthy controls were analyzed by quantitative real-time PCR. ELISA was used to test the IL-17 and IL-23 levels in plasma. Flow cytometry was used to detect the frequency of Th17 cells. The correlation between plasma IL-23 and IL-17 levels, Th17 cells, platelets were analyzed. The level of Th17-related cytokines was measured by ELISA following stimulation with IL-23. Subsequently, the IL-23 and IL-17 levels were measured in patients post-treatment.

Results

The PBMCs of ITP patients showed increased mRNA expression levels in each of the following: IL-23p19, IL-12p40, IL-23R, IL-12Rβ1, IL-17A, IL-17F, and RORC. In addition, elevated Th17 cells and plasma IL-17, IL-23 levels were also observed in these ITP patients. Furthermore, it was found that IL-23 levels in plasma are positively correlated with IL-17 levels and Th17 cells, yet negatively correlated with platelet count. Following IL-23 stimulation in vitro, IL-17 levels showed significant elevation. Furthermore, both IL-23 and IL-17 levels decreased after effective treatment.

Conclusion

The IL-23/Th17 pathway may be involved in the pathogenesis of ITP through enhancement of the Th17 response. Moreover, our results suggest that the IL-23/Th17 pathway is a potential therapeutic target in future attempts of ITP treatment.

Dapsone for primary immune thrombocytopenia in adults and children: an evidence-based review

Primary immune thrombocytopenia is a potentially life-threatening condition. Approximately two-thirds of adult patients do not have a sustained response to steroids (first-line therapy). For these patients, a number of other treatment options exist, such as rituximab, splenectomy, immunosuppressants, and thrombopoietin receptor agonists, but they are costly and have side effects. Dapsone is an inexpensive drug with a well-established safety profile. Unfortunately, this treatment option has not been explored adequately. This review is aimed at analyzing the currently available evidence for the use of dapsone as second-line or third-line therapy in primary immune thrombocytopenia.