Chronic Immune Thrombocytopenic Purpura In Children Research Articles

Chronic Thrombocytopenia in Children: What Could It Hide?

Immune thrombocytopenic purpura (ITP) is one of the most common hemorrhagic disorders in childhood, often caused by an acute self-limiting event. However, 30% of these children develop chronic ITP. Identification of the underlying causes in ITP is an important challenge. Inherited thrombocytopenia (IT) is a rare, underdiagnosed disease, included among the chronic platelet disorders. Next-Generation-Sequencing (NGS) could be an efficient way of discovering potential IT-associated mutations in children with chronic ITP. The purpose of this retrospective study was to investigate children with chronic ITP using a targeted NGS, in order to identify IT-associated mutations. Between June 2017 and April 2020, mutational screening by a targeted NGS was performed on 19 children, either with a familial history of IT [4 unrelated patients (pts)], or with chronic ITP (15 pts), after all other causes of thrombocytopenia were excluded. Nineteen relatives were also investigated. This study was carried out in collaboration with the Laboratory of Genetics, IRCCS Burlo Garofolo in Trieste, that developed a targeted NGS method for the simultaneous analysis of 28 IT genes. The cost of the NGS tests were supported by the public healthcare service. We retrospectively divided our cohort of 19 pts, into three subgroups: Group I included 4 unrelated pts with familial IT; Group II consisted of 6 pts with chronic ITP and a clinical history and/or laboratory features associated with familial IT; and, Group III included 9 pts with chronic ITP refractory to several treatments (Table 1). The median age at the initial diagnosis of thrombocytopenia was lower in Group I than in Groups II and III (19/12 years vs 1310/12 years and 9 years, respectively, p=0.33). The median time between the diagnosis of thrombocytopenia, and the time of the study, was shorter in Group I compared to Groups II and III (11.7 months vs 45.3 and 51.7 months, respectively, p=0.16). Median platelet count at the disease onset was lower in Group III than in Groups I and II (21 x 109/L vs 99 x 109/L and 38 x 109/L, respectively, p=0.28). The median MPV values were 12.5 fL, 9.85 fL and 8.8 fL in Groups II, III, and I respectively. Bleeding symptoms requiring treatment were present at diagnosis in 1/6 (16%) and in 5/9 (55%) children of Groups II and III, respectively. Genetic variants, usually detected in IT, were found in heterozygosity in all children in Groups I and II, and in 7/9 (78%) in Group III. Two out of 4, 2/6 and 2/9 children in Groups I, II, and III, respectively, presented ≥2 variants. Among the 4 children of Group I, ANKDR26 variant was found in 2 pts, together with GP1BA and NBEAL2 (pt#1) and TUBB1 (pt#2). ANKDR26 variant was also recorded as a single mutation in their relatives. Two different variants involving GP1BA (c.98T>A and c.515C<T) were detected in the remaining 2 children of Group I and in their relatives. Pt #4 with GP1BA c.515C>T mutation with mild macrothrombocytopenia had relatives with a previous diagnosis of monoallelic Bernard-Souliers syndrome. As shown in table 1, ABCG8, ACTN1, ETV6, GP1BA, MYH9, SLFN14, or WAS variants, found in combination in 2 pts (pt#5, pt#8), were also detected in the children in Group II, as well as, at least one of the relatives (for a total of 7 cases). ABCG5, ABCG8, ETV6, FLNA, GP1BA, NBEAL2, or SLFN14 were found as variants in patients of Group III. The peripheral blood smear evaluation confirmed the diagnosis of grey platelet syndrome with two NBEAL2 mutations in pt #16. SLFN14, as a single variant, was associated with macrothrombocytopenia in one pt (#10). Three pts (#5, #6, #17), with variants of ABCG8 had hypercholesterolemia. In the cohort of pts with chronic ITP, 4 (#12, #13, #14, #15) had relatives with thrombocytopenia, and 2 (#11, #13) had a familial history of hematological malignancies. Segregation analysis in families, and functional studies to evaluate the pathogenic role of the variants reported, are still in progress. The clinical significance of IT-associated mutations in chronic ITP is uncertain, and yet to be clarified. However, our experience has shown that an in-depth clinical history, and accurate peripheral blood smear examinations, are important to better characterize chronic ITP in children. A targeted NGS method for the simultaneous analysis of different IT genes, has demonstrated to be an effective approach to explore in-depth the IT-associated mutations in children with chronic ITP, refractory to treatment. Table 1. Disclosures Giona: Novartis: Research Funding; Takeda: Speakers Bureau; Sanofi Genzyme: Research Funding, Speakers Bureau.

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

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 18years 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 sixyears (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.

The use of anti-CD20 in management of Egyptian children with chronic immune thrombocytopenic purpura

Background/aim Chronic immune thrombocytopenic purpura (ITP) is an immune-mediated platelet destruction, with decreased platelet count to less than 100×109/l for more than 12 months. Overall, 5–10% of children with chronic ITP experience serious bleeding, and their treatment is challenging. Rituximab is one of treatment options. Our aim is to evaluate low-dose rituximab in the management of childhood chronic ITP. Patients and methods Twenty-eight children with primary chronic ITP were prospectively administered rituximab at a dose of 100 mg/week for 4 weeks and followed up for 1 year. Results The initial response showed that 12/28 (42.8%) achieved complete remission, 2/28 (7%) minimal remission and 14/28 (50%) no remission. No significant differences were detected between responders and nonresponders regarding age and sex (P=0.94 and 0.59, respectively), except that the duration of the disease was significantly longer among nonresponders (P=0.025). The outcome after 1-year follow-up was as follows: one patient lost to follow-up, 14/28 (50%) were nonresponders, 8/28 (28%) relapsed, and 6/28 (21%) maintain sustained remission. Conclusion Rituximab is one of treatment choices for chronic ITP in children with convincing initial results; however, failure to achieve sustained remission is still a problem.

Prognostic Significance of IL-10 in Childhood Chronic Immune Thrombocytopenic Purpura

Background: The proposal of the present study was to assess the cytokine imbalances such as serum levels of IL-2, IL-10 and TGF-1 in childhood chronic ITP during the thrombocytopenic and spontaneous remission phases. The findings of this study are anticipated to offer new insights into the pathogenesis of childhood chronic ITP and the prognostic factors involved in spontaneous remission. Methods: Ten children with chronic ITP, 6 thrombocytopenic and 4 recovered cases, were enrolled. Five healthy children and eight healthy adults were included in this study as controls. The serum levels of IL-2, IL-10 and TGF- 1 were measured by ELISA technique. Results: During this study, four patients achieved spontaneous remission. The serum level of IL-10 was higher in the patients that recovered spontaneously compared to the patients with persistent chronic thrombocytopenia. The serum level of IL-2 was not able to be detected as the levels were too low for analysis. TGF- 1 showed no significant differences among the groups in this study. Conclusion: These data suggest that increased serum level of IL-10 could have prognostic significance in the natural course and long-term outcome of childhood chronic ITP.

Association of CD4(+)CD25(+)FoxP3(+) regulatory T cells with natural course of childhood chronic immune thrombocytopenic purpura.

PurposeThe purpose of this study was to determine the frequency of CD4+CD25+FoxP3+ regulatory T cells (Treg) in the peripheral blood of patients with childhood chronic immune thrombocytopenic purpura (ITP) exhibiting thrombocytopenia and spontaneous remission. The findings of this study indicate the possibility of predicting spontaneous recovery and pathogenesis of childhood chronic ITP.MethodsEleven children with chronic ITP (seven thrombocytopenic and four spontaneous remission cases; mean age, 8.8 years; range, 1.7-14.9 years) were enrolled in this study. Five healthy children and eight healthy adults were included as controls. The frequency of Treg was evaluated by flow cytometry in the peripheral blood.ResultsIn this study, four patients (36%) achieved spontaneous remission within 2.8 years (mean year; range, 1.0-4.4 years). The frequency of Treg was significantly lower in patients with persisting thrombocytopenia (0.13%±0.09%, P<0.05), than that in the patients with spontaneous remission (0.30%±0.02%), healthy adults controls (0.55%±0.44%), and healthy children controls (0.46%±0.26%). A significantly positive correlation was found between the frequency of Treg and the platelet count in children.ConclusionThese data suggest that a lower frequency of Treg contributes to the breakdown of self-tolerance, and may form the basis for future development of specific immunomodulatory therapies. Furthermore, Treg frequency has prognostic implication toward the natural course and long-term outcomes of childhood chronic ITP.

Platelet apoptosis resistance and increased CXCR4 expression in pediatric patients with chronic immune thrombocytopenic purpura

The pathogenesis of childhood chronic immune thrombocytopenic purpura (ITP) is mainly mediated by antiplatelet autoantibodies, which have been shown to induce platelet apoptosis in murine models. Decreased CXCR4 expression, which can regulate apoptotic pathway, has been described in platelet disorders. The present study aims to determine whether platelet apoptosis is increased in pediatric patients with chronic ITP and whether there is any involvement of the CXCR4 chemokines axis. Twenty-one patients and 12 controls were studied. Using flow cytometry, we investigated apoptotic markers of platelets including annexin V, caspase 3, and mitochondrial inner transmembrane potential depolarization. The percentage of the platelets with apoptosis-positive markers was not increased in chronic ITP patients. CXCR4 expression was higher in the patients as detected by flow cytometric ( P = 0.001) and western blotting analysis ( P = 0.013). The results also revealed that CXCR4 downstream proteins, Akt phosphorylation was more frequent in chronic ITP patients than controls. Plasma stromal cell-derived factor 1 levels analyzed by enzyme-linked immunosorbent assay were decreased in patients ( P = 0.001) and inversely correlated to CXCR4 expression ( r = -0.62, P < 0.001). In conclusion, the study shows platelet apoptosis resistance existing in pediatric patients with chronic ITP. It may be associated with enhanced CXCR4 expression and Akt activation.

Natural Course in Childhood Chronic Immune Thrombocytopenic Purpura (ITP) and Their Relation to CD4+CD25+FoxP3+ Regulatory T Cells.

Abstract 1318Poster Board I-341 PurposeThe proposal of the present study was to determine the frequency of CD4+CD25+FoxP3+ regulatory T cells (Treg) in the peripheral blood and to assess the serum levels of IL-2, IL-10 and TGF-β1 in childhood chronic ITP with thrombocytopenia and spontaneous remission. In anticipation of the findings would elucidate the possible role in order to predict spontaneous recovery and pathogenesis of childhood chronic ITP. Patients and MethodsEleven children with chronic ITP (7 thrombocytopenic and 4 recovered cases, mean age 8.8 years; range, 1.7∼14.9 years) were enrolled. Five healthy children and eight healthy adults were included in this study as controls. The frequency of Treg was evaluated in peripheral blood by flow cytometry. The serum levels of IL-2, IL-10 and TGF-β1 were measured by ELISA technique. ResultsDuring this study, it was observed that four patients (36%) achieved spontaneous remission within 2.8 years (mean year; range, 1.0∼4.4 years). The frequency of Treg was significantly decreased in the patients with thrombocytopenia as compared to spontaneously recovered patients and controls. A significant positive correlation was found between the frequency of Treg and the platelet count in children. The serum level of IL-10 was higher in the patients recovered spontaneously comparing to the patients with thrombocytopenia, but the difference was not significant statistically. The serum level of IL-2 was not able to detect as too low to be analyzed. TGF-β1 showed no significant differences in this study. ConclusionThese data suggest that the decreased frequency of Treg would contribute to breakdown of self-tolerance as well as form a base for future specific immunomodulatory therapies and have prognostic significances toward the natural course and long-term outcome of childhood chronic ITP. DisclosuresNo relevant conflicts of interest to declare.

H. pylori infection in childhood chronic immune thrombocytopenic purpura

Several studies have reported remission of immune thrombocytopenic purpura ( ITP) after eradication of a coexistent Helicobacter pylori infection in adults. Data in children are limited. Here we report the results of a prospective study of Helicobacter pylori determination and eradication in children with chronic ITP in the Netherlands.

Interleukin 4, interleukin 6 and interleukin 10 polymorphisms in children with acute and chronic immune thrombocytopenic purpura

Immune thrombocytopenic purpura (ITP) is an immune-mediated disorder. We investigated the polymorphisms of interleukin (IL)-4 intron 3, IL-6 (-572 G/C), and IL-10 (-627 C/A) in 50 children with acute ITP, 30 children with chronic TIP, and 100 healthy individuals. There were significant differences in the RP1/RP2 genotype proportion (P = 0.04) and the RP2 allelic frequency (P = 0.03) of IL-4 intron 3 and the A/C genotype proportion (P = 0.01) of IL-10 (-627) between children with chronic ITP and controls. This finding suggests that the IL-4 intron 3 and IL-10 (-627) polymorphisms contribute to the susceptibility of developing childhood chronic ITP.

Childhood chronic immune thrombocytopenic purpura: unresolved issues.

Chronic immune thrombocytopenic purpura (ITP), defined as a platelet count of below 150 x 109/L persisting for more than 6 months from onset of illness, occurs in approximately 20% to 25% of children with acute-onset ITP. A small subset of these patients (approximately 5%) will manifest symptomatic, severe thrombocytopenia (platelet counts <20 x 109/L) at 1 year or longer following diagnosis, and may require splenectomy. Complete/partial response rates following splenectomy in children with primary chronic ITP are of the order of 70% to 75%; response rates are lower in children with secondary ITP and those with complex autoimmune cytopenias (e.g., Evans syndrome). Laparoscopic splenectomy is increasingly preferred over open splenectomy. Patients should be immunized with the pneumococcal, Haemophilus type b and meningococcal vaccines before splenectomy; the duration of postsplenectomy antibiotic prophylaxis using penicillin or an equivalent antibiotic is controversial but should be at least until 5 years of age and for a minimum of 1 year postsplenectomy. Some experts advocate life-long antibiotic prophylaxis. Treatment of postsplenectomy failures is a challenge; partial/complete remission rates are low, and multimodality therapy may be more efficacious than monotherapy. The presence of an accessory spleen should be sought and removal considered if present. The role of newer treatment modalities such as anti-CD 20 remains to be established.

Childhood chronic immune thrombocytopenic purpura (ITP)

Chronic immune thrombocytopenic purpura (ITP) develops in approximately 20% of children with acute ITP. Treatment requires differentiating the truly idiopathic state from thrombocytopenias associated with other disorders. Treatment is recommended in cases where platelet counts drop below 20×109/L. Therapeutic options include corticosteroids, intravenous immunoglobulin TG(IVIg), and anti-D, as well as splenectomy. The benefits and disadvantages of each modality are reviewed, as well as the management of postsplenectomy failures.

Polymorphisms in inflammatory cytokines and Fcgamma receptors in childhood chronic immune thrombocytopenic purpura: a pilot study.

Inflammatory cytokines and low-affinity Fcgamma receptor (FcgammaR) polymorphisms were investigated in 37 children with chronic immune thrombocytopenic purpura (cITP) and 218 controls. Genotype analysis included common variants in the regulatory regions of cytokines, TNF, LTA, IL1RN, IL1A, IL1B, IL4, IL6 and IL10, and structural variants of the low affinity FcgammaRs, FCGR2A, FCGR3A and FCGR3B. Associations were observed for TNF (P = 0.0032), LTA (P = 0.019), FCGR3A (P = 0.038) and FCGR3B (P = 0.0034). Two combinations of genotypes (TNF and FCGR3A; P = 0.0003, and LTA and FCGR3B; P = 0.011) were significantly associated with cITP. These results provide preliminary evidence that variant genotypes of FcgammaRs and cytokines contribute to cITP pathogenesis.

Platelet and immune responses to oral cyclic dexamethasone therapy in childhood chronic immune thrombocytopenic purpura

Objective: To examine the effectiveness of cyclic oral high-dose (HD) dexamethasone therapy in pediatric patients with chronic immune thrombocytopenic purpura (ITP), which has been reported to cause complete remission in adults with chronic ITP. Study design: Eleven children with primary chronic ITP, with a median disease duration of 28 months (range, 6 to 120 months), were treated with cycles of HD dexamethasone therapy. Results: Excellent short-term responses (initial platelet counts ≤50 × 10 9 /L, increasing to >100 × 10 9 /L within 72 hours of completion of an HD dexamethasone cycle) were observed in 78% of 41 cycles. Long-term effects include one complete response (platelet count ≥150 × 10 9 /L) and three partial responses (platelet count ≥50 and <150 × 10 9 /L) in 11 children followed for 6 or more months after completing cyclic HD dexamethasone therapy. Because side effects were substantial, three children did not complete their sixth treatment cycle. At day 6 of treatment, B lymphocytes were significantly increased ( p = 0.005). Conclusions: Dexamethasone, given orally in high doses, is an effective drug in achieving short-term platelet responses, but it induced long-term remissions in fewer than half of the children with well-established chronic ITP. Its effect on B lymphocytes requires further elucidation. A prospective, controlled study will be needed to establish whether cyclic HD dexamethasone therapy can alter the natural history of children with early chronic ITP and thus avoid splenectomy. (J Pediatr 1997;130:17-24)

Immunthrombocytopenic purpura as a model for pathogenesis and treatment of autoimmunity.

In honour of Professor Rossi's 80th birthday we review the development of our understanding of the immune and auto-immune nature of the pathogenesis of immune thrombocytopenic purpura (ITP). The immune aspects have been documented by postviral alterations of the cellular and humoral immune system, by new methods of specific auto-antibody detection against platelet glycoproteins and by the therapeutic effect of administering immunoglobulin concentrate from healthy blood donors. The various possible mechanisms of action of immunoglobulin treatment have led to use of this treatment as an alternative for other immune-related disorders. The treatment of severe chronic ITP in children, however, remains unsatisfactory. With a new international clinical and laboratory study of children and adolescents with early chronic ITP we are continuing the investigation of the pathogenesis and treatment of ITP.

Autoantibodies Against Platelet Membrane Glycoproteins in Children With Acute and Chronic Immune Thrombocytopenic Purpura

The autoimmune nature of chronic immune thrombocytopenic purpura (ITP) in adults is widely accepted. In contrast, the pathogenetic mechanism in acute and chronic ITP in children is not known. In this report, we studied 39 children with destructive thrombocytopenia, 15 patients with acute ITP and 24 patients with chronic ITP. Platelet autoantibodies to platelet glycoprotein IIb/IIIa were detected in 14 of 24 patients (58.3%) in the chronic ITP group and in four of 15 (26.7%) with acute ITP. Binding ratios (+/- SD) of positive patients were significantly greater (P = .01) in chronic ITP (8.0 +/- 9.1) when compared with those of acute ITP where the binding ratios were only slightly above the normal range (1.9 +/- 0.4). The results show that autoantibodies against platelet glycoproteins are present in the majority of children with chronic ITP confirming the autoimmune nature of this disorder. The minimal elevation seen in the positive children with acute ITP suggests a different pathogenetic mechanism. These data suggest that this approach may be useful in differentiating acute from chronic ITP patients.

Autoantibodies against platelet membrane glycoproteins in children with acute and chronic immune thrombocytopenic purpura

The autoimmune nature of chronic immune thrombocytopenic purpura (ITP) in adults is widely accepted. In contrast, the pathogenetic mechanism in acute and chronic ITP in children is not known. In this report, we studied 39 children with destructive thrombocytopenia, 15 patients with acute ITP and 24 patients with chronic ITP. Platelet autoantibodies to platelet glycoprotein IIb/IIIa were detected in 14 of 24 patients (58.3%) in the chronic ITP group and in four of 15 (26.7%) with acute ITP. Binding ratios (+/- SD) of positive patients were significantly greater (P = .01) in chronic ITP (8.0 +/- 9.1) when compared with those of acute ITP where the binding ratios were only slightly above the normal range (1.9 +/- 0.4). The results show that autoantibodies against platelet glycoproteins are present in the majority of children with chronic ITP confirming the autoimmune nature of this disorder. The minimal elevation seen in the positive children with acute ITP suggests a different pathogenetic mechanism. These data suggest that this approach may be useful in differentiating acute from chronic ITP patients.