Prognostic implications for direct platelet-associated IgG in childhood idiopathic thrombocytopenic purpura

To determine the value of the direct platelet associated IgG (PAIgG) level as a prognostic indicator in childhood idiopathic thrombocytopenia purpura (ITP), 18 children with ITP were studied. Ten of the 18 had PAIgG levels measured at diagnosis, before any therapy. Of these 10 patients, six (Group I) had an acute course, with a mean initial platelet count of 15 X 10(9)/liter and a mean initial PAIgG level of 330.9 fg/plt. Four patients (Group II) had a chronic course, with a mean initial platelet count of 11 X 10(9)/liter and a mean initial PAIgG level of 38.3 fg/plt. There was no significant difference between the mean initial platelet count of Groups I and II (p greater than 0.10), but the initial PAIgG levels in those patients with an acute course were significantly higher than the levels in those patients with a chronic course (p less than 0.05). Of the original 18 patients, nine were splenectomized for chronic thrombocytopenia, with normalization of the platelet count in all instances. Of these splenectomized patients, five had platelet counts and PAIgG levels measured before and after splenectomy. All five had normal PAIgG levels following splenectomy. The PAIgG level is a good prognostic indicator for the clinical course of childhood ITP. A high PAIgG level suggests an acute course while a modestly elevated level suggests a chronic course. The PAIgG level normalizes in remission after splenectomy.     

Evaluation of a simple immunodiffusion technique for quantitation of platelet-associated immunoglobulin G in childhood immune thrombocytopenias

Platelet-associated IgG (PAIgG) was quantitated in 33 children with immune thrombocytopenia and platelet counts less than 100 X 10(9)/liter using a simple radial immunodiffusion (RID) assay. Elevated PAIgG levels were found in 76% (16/21) of children with acute idiopathic thrombocytopenic purpura (ITP), 88% (7/8) of children with chronic ITP, and all four children studied with systemic lupus erythematosus and thrombocytopenia. Normal PAIgG values were found in children with the following disorders: malignancy and chemotherapy-related thrombocytopenia; ITP in remission (platelet counts greater than 150 X 10(9)/liter); various nonimmune hematologic disorders and juvenile rheumatoid arthritis, these children having normal platelet counts. In children with acute ITP, elevated PAIgG values at initial presentation fell to within the normal range when clinical remission occurred. The RID assay can be easily established in most hematology laboratories and has the advantage that solubilized "test" platelets used in the assay can be stored frozen prior to analysis. We conclude that this simple technique is of value in the evaluation of childhood thrombocytopenic states and yields results comparable to those reported using more complex antiplatelet antibody assays.     

Platelet-Associated IgG in Children - Values and Evaluation of PAIgG in Various Thrombocytopenias -

Platelet-associated IgG (PAIgG) levels were measured in 60 children with ITP (46-chronic, 14-acute) using Fab-anti Fab radioimmunoassay method described by McMillan et al. In some patients platelet binding IgG in serum (PBIgG) was also determined at the same time. Patients with ITP had significantly greater PAIgG levels than 30 normal subjects and 13 non-immune thrombocytopenic controls. Elevated PAIgG values did not correlate with parameters of platelet size (mean platelet volume; MPV and percentage of large platelet; PLP) and so these data indicated that high levels of PAIgG in ITP were not due to nonspecific adhesion of serum IgG to megathrombocytes usually increased in this disorder, but due to specific immunological reaction. PBIgG IgG values were also elevated in patients with pretreated chronic ITP, but high levels remained even after successful splenectomy. Furthermore, serial determination of PAIgG values were obtained in some patients with chronic ITP who underwent splenectomy and with acute ITP who achieved spontaneous remission. PAIgG returned to normal levels when thrombocytopenia disappeared. PAIgG seems to be the most reproducible indicator which reflects transition of the clinical picture in this disorder.     

Platelet antibody in prolonged remission of childhood idiopathic thrombocytopenic purpura

Evaluations were performed in 20 patients with childhood idiopathic thrombocytopenic purpura (ITP) who remained in remission longer than 12 months. The mean duration of follow-up from diagnosis was 39 months (range 17 to 87 months). Eleven patients (four girls) in group 1 had an acute course of ITP, defined as platelet count greater than 150 X 10(9)/L within 6 months of diagnosis. Nine patients (five girls) in group 2 had a chronic course, defined as platelet count less than 150 X 10(9)/L for greater than or equal to 1 year or requiring splenectomy in an attempt to control hemorrhagic symptoms. Mean age at diagnosis and duration of follow-up were similar for both groups. Platelet count and serum (indirect) platelet-associated IgG (PAIgG) levels were normal in all 20 patients at follow-up. Both direct and indirect PAIgG levels were measured using a 125I-monoclonal anti-IgG antiglobulin assay. All had normal direct PAIgG levels, except for one patient in group 1 who had a borderline elevated value of 1209 molecules per platelet. These data suggest that the prevalence of elevated platelet antibodies is low during sustained remission without medication in patients with a history of childhood ITP. These data may be relevant for pregnant women with a history of childhood ITP, with regard to the risk of delivering an infant with thrombocytopenia secondary to transplacental passage of maternal platelet antibody.     

Agenesis of the Corpus Callosum and Neural Crest Tumors

Hematologic abnormalities, including thrombocytopenia, are seen in HIV infection. Mi have previously reported elevated platelet-associated IgG (PAIgG) in thrombocytopenia in children associated with human immunodeficiency virus (HIV). In this study we prospectively monitored 40 HIV-infected infants and children to determine the significance of elevated PAIgG levels as they relate to thrombocytopenia. We also examined platelet eluatesfor the presence of HIV antibody and antigen. Of 16 patients with thrombocytopenia, 15 (93.7%) had elevated PAIgG. Of 24 patients with normal platelet counts, 21 (87.5%) had elevated PAIgG. On follow-up, none of the children with normal platelet counts and elevated PAIgG levels developed thrombocytopenia. Examination of the platelet eluates was negative for HIV antibody or P24 antigen. Although the sensitivity of an elevated PAIgG level in predicting thrombocytopenia is 93%, its specificity is only 13%. Elevated PAIgG levels are therefore not causally related to the development of thrombocytopenia in children.     

Platelet-Associated IgG in Pediatric HIV Infection

Hematologic abnormalities, including thrombocytopenia, are seen in HIV infection. Mi have previously reported elevated platelet-associated IgG (PAIgG) in thrombocytopenia in children associated with human immunodeficiency virus (HIV). In this study we prospectively monitored 40 HIV-infected infants and children to determine the significance of elevated PAIgG levels as they relate to thrombocytopenia. We also examined platelet eluatesfor the presence of HIV antibody and antigen. Of 16 patients with thrombocytopenia, 15 (93.7%) had elevated PAIgG. Of 24 patients with normal platelet counts, 21 (87.5%) had elevated PAIgG. On follow-up, none of the children with normal platelet counts and elevated PAIgG levels developed thrombocytopenia. Examination of the platelet eluates was negative for HIV antibody or P24 antigen. Although the sensitivity of an elevated PAIgG level in predicting thrombocytopenia is 93%, its specificity is only 13%. Elevated PAIgG levels are therefore not causally related to the development of thrombocytopenia in children.     

Platelet-associated immunoglobulin G in childhood idiopathic thrombocytopenic purpura

Childhood ITP is an acquired hemorrhagic disorder with a heterogeneous clinical course. We measured PAIgG levels in 20 children with ITP (7 acute, 13 chronic). Both groups had significantly greater PAIgG values than age-matched normal subjects and thrombocytopenic controls (P less than 0.001). In addition, PAIgG values in chronic ITP were significantly lower than those in acute ITP (P less than 0.003). Serial PAIgG values were obtained in some patients; most returned to normal in association with clinical recovery. The measurement of PAIgG is useful in the diagnosis and follow-up of childhood ITP. PAIgG values may assist in differentiating acute and chronic disease in children.     

Soluble P-selectin,interleukin 6, and thrombopoietin levels in children with acute and chronic idiopathic thrombocytopenic purpura and their relationship with mega-dose methylprednisolone therapy: a pilot study

We observed less severe symptoms in patients with chronic idiopathic thrombocytopenic purpura (ITP) than in patients with acute ITP with similar platelet counts. Thrombopoietin (TPO), soluble P-selectin, soluble P-selectin per platelet, and interleukin 6 (IL-6) were evaluated in children with ITP before treatment in 16 acute and 22 chronic cases and after treatment in 10 acute and chronic cases who received mega-dose methylprednisolone. The levels of IL-6, soluble P-selectin, soluble P-selectin per platelet, and platelet count were similar in acute and chronic ITP (P > 0.05) but TPO in acute ITP was higher than that of the patients with chronic ITP (P < 0.05). The posttreatment IL-6 and TPO declined (P < 0.05), but soluble P-selectin and platelet count increased (P < 0.05). Posttreatment soluble P-selectin per platelet levels were higher than the normal values (P < 0.05). These results suggest that IL-6, soluble P-selectin, and soluble P-selectin per platelet are not responsible for the milder symptoms in chronic than in acute ITP. Mega-dose methylprednisolone seems to keep the soluble P-selectin levels elevated.     

Childhood immune thrombocytopenic purpura: diagnosis and management

Immune thrombocytopenic purpura (ITP) is an autoimmune disorder characterized by a low circulating platelet count caused by destruction of antibody-sensitized platelets in the reticuloendothelial system. ITP can be classified as childhood versus adult, acute versus chronic, and primary versus secondary. Persistence of thrombocytopenia defines the chronic form of the disorder. Secondary causes of ITP include collagen vascular disorders, immune deficiencies, and some chronic infections. This review focuses on the diagnosis and management of children who have acute and chronic ITP. Emphasis is placed on areas of controversy and new therapies.     

小儿特发性血小板减少性紫癜血小板相关抗体、T细胞亚群检测及其临床意义

本文对1989年9月至1995年2月收治的112例小儿特发性血小板减少性紫癜的血小板相关性抗体、T细胞亚群检测及其临床意义进行了探讨。结果表明：急、慢型无论是OKT3及OKT4+均低于正常对照组，且有显著性差异，P值均＜0．05；而OKT8+与正常对照组相比则较高，P值＜0．025。但是，急、慢两型相比均未见统计学上显差性差异。本文的检测血小板抗体lgG、IgM及IgA，显示均有所增高尤以PAIgG最明显，阳性率达85．7％，与文献报道近似。经治疗10例血小板动态变化，PAIg随着血小板的恢复均下降至正常，呈负相关.     

Management of immune thrombocytopenic purpura: A prospective study of 147 children from the regional network RHémaP

AIM: Assessment of the impact of guidelines from a regional pediatric network to standardize the management of childhood immune thrombocytopenic purpura (ITP). MATERIALS AND METHODS: Consensus guidelines were drawn up in centers of the pediatric network for hematological diseases, RHémaP, and a cohort of children referred for ITP in these centers was set up. A 1-year follow-up was recorded for each patient over a 43-month period. RESULTS: We report data from a cohort of 147 children. At diagnosis, we recorded severe thrombocytopenia (median=8G/l) and 141 children had hemorrhagic symptoms (96%). Only 23 children had a bone marrow aspiration (BMA) at diagnosis (16.3%), which meant a high level of implementation of the RHémaP recommendations (96%) since indications of BMA were limited to rare indications. For 135 children (91.8%), treatment fulfilled the RHémaP guidelines that were mainly based on the platelet count: 121 received intraveinous immunoglobulin (IVIG) and 14 were not treated. Among those who received IVIG, 110 were good responders (91%) at the 96-h evaluation (platelet count greater than 20G/l), nine (7.4%) were poor responders, and 1 died of intracranial hemorrhage. At 6 months, chronic ITP was observed in 40 children (32.8%). Chronic ITP was associated with a higher platelet count at diagnosis and an older age (p<10(-3) and p=10(-3), respectively). CONCLUSION: The practices recorded over a 43-month period in our cohort fulfilled the RhémaP guidelines and we conclude that we managed to standardize regional practices for children with ITP. We observed conventional epidemiological characteristics in this cohort. Older children and higher platelet count at diagnosis were significantly associated with higher frequency of chronic ITP.     

Duration and morbidity of chronic immune thrombocytopenic purpura in children: five-year follow-up of a Nordic cohort

Aim: To describe the clinical course, morbidity and platelet recovery in an unselected Nordic cohort of children with chronic Immune Thrombocytopenic Purpura (ITP). Methods: Prospective 5‐year follow‐up of 96 children with ITP lasting more than 6 months, with reporting of hospital admissions, severity of bleeding episodes and stabilization of platelet counts above 20, 50 and 150 × 10⁹/L. Results: The estimated 5‐year recovery rate was 52%; exclusion of 12 splenectomized children did not change the estimate. Events eliciting admission to hospital occurred in 39 (41%). Major haemorrhages occurred in eight children (8%), including a nonfatal intracranial haemorrhage in one child (1%). The overall admission rate was 0.4/year of thrombocytopenia, decreasing during follow‐up as thrombocytopenia converted to milder degrees. Early recovery within 2 years of diagnosis occurred in 35%, was associated with low morbidity and was more likely in young children with abrupt onset of symptoms. Conclusion: In a Nordic cohort of children with chronic ITP, one half had recovered 5 years after diagnosis, more than half never required hospitalization and <10% experienced serious bleeding episodes, always with a platelet count <20 × 10⁹/L. Aggressive management can be restricted to the minority of children with continuing severe thrombocytopenia and frequent, clinically significant bleeding events.     

Childhood ITP: 12 months follow-up data from the prospective registry I of the Intercontinental Childhood ITP Study Group (ICIS)

BACKGROUND: Acute and chronic idiopathic thrombocytopenic purpura (ITP) is traditionally based on the duration of thrombocytopenia at the cut-off point of 6 months after diagnosis. Registry I evaluated the diagnosis, definition, management, and follow-up of childhood ITP. This report focuses on children with thrombocytopenia persisting more than 6 months. PROCEDURE: Data were collected by questionnaires to the physicians caring for children with ITP, at diagnosis, 6, and 12 months later. Data were compared regarding initial features and follow-up with emphasis on children with persistent thrombocytopenia, and those with ITP who recovered their platelet counts between 7 and 12 months from diagnosis. RESULTS: At 12 months from diagnosis, 79 of 308 (25.6%) evaluable children recovered from ITP and 229 had ongoing ITP. Children with recovered ITP were younger than children with ongoing ITP (P = 0.043) and exhibited a lower frequency of bleeding symptoms during the first 6 months after diagnosis (P = 0.018). Frequency of hospitalization, bone marrow aspiration, and drug treatment differed regionally. CONCLUSIONS: The high rate of recovery from ITP between 7 to 12 months demonstrates, that the cut-off point of 6 months for the definition of chronic ITP does not adequately differentiate chronic from acute ITP. The majority of children with ITP have variable time to recovery with gradual improvement of platelet counts and disappearance of bleeding signs. ITP is a heterogeneous disorder with a diverse natural history and diverse pattern of treatment response.     

Chronic immune thrombocytopenic purpura in children: a survey of the canadian experience

BACKGROUND: Immune thrombocytopenic purpura (ITP) in children is a common pediatric bleeding disorder with heterogeneous manifestations and a natural history that is not fully understood. To better understand the natural history of chronic ITP and detect response trends and outcomes of therapy, we conducted a 10-year retrospective survey of children from age 1 to 18 years with a diagnosis of chronic ITP. RESULTS: Data on 198 patients from 8 Canadian Pediatric Hematology/Oncology centers were analyzed. The majority of patients were female (58%), and were previously diagnosed with acute (primary) ITP (85%). The age at diagnosis of chronic ITP ranged from 1.1 to 17.2 years with a mean of 8.2+/-4.4 years. Ninety percent of patients received some form of treatment. Untreated patients had a higher mean platelet count at diagnosis of chronic ITP (P=0.009) despite similarities in mean age at first presentation and mean duration of follow-up. Thirty-four (17%) patients underwent splenectomy. Splenectomized patients tended to be significantly older, had a lower mean platelet count at diagnosis of chronic ITP, and had a longer duration of follow-up. CONCLUSIONS: The results from this study are consistent with published reports.     

Post‐varicella thrombocytopenic purpura

Aims: The aim of the study was to characterize the clinical course of post‐varicella idiopathic thrombocytopenic purpura (ITP) and to asses the risk of acquiring ITP after varicella infection. Methods: A retrospective study of all children diagnosed with ITP in a tertiary medical centre during 1998–2008. Findings were compared with the Intercontinental Childhood ITP Study Group database. The risk of acquiring ITP after a varicella infection was assessed. Results: Ten children were diagnosed with post‐varicella ITP. The incidence of post‐varicella ITP was 1.9% amongst children diagnosed with ITP and 1.1% amongst children hospitalized for varicella. ITP was diagnosed, on average, 8.5 days after the onset of the varicella rash. The female‐to‐male ratio was 1:1.5. The average minimal platelet count was 9.5 × 10⁹ platelets/L. Post‐varicella ITP had an acute course in 80% of cases and a chronic course in the remaining 20%. Bleeding episodes occurred in three patients. During the follow‐up period, 11 patients with previously diagnosed ITP developed varicella. The infection had no apparent affect on the platelet count of the children with acute ITP, but caused a relapse in 71% of the patients with chronic ITP. Conclusions: Post‐varicella ITP has similar clinical features and course to non‐varicella associated ITP. The calculated risk of ITP as a complication of varicella infections is approximately 1:25 000.     

Duration and morbidity of newly diagnosed idiopathic thrombocytopenic purpura in children: A prospective Nordic study of an unselected cohort

OBJECTIVE: To determine the duration of the risk period with platelet counts <20 x 10(9)/L and the frequency of bleeding episodes in unselected children with idiopathic thrombocytopenic purpura (ITP). STUDY DESIGN: We established a registry for patients with newly diagnosed ITP in the five Nordic countries, enrolling children aged 0 to 14 years with platelet counts <30 x 10(9)/L. Treatment centers prospectively reported presenting features, management details, and disease-related events during the first six months after diagnosis. RESULTS: At presentation (n=501), more than half of the children had a platelet count <10 x 10(9)/L, but only 15 (3.0%) had a hemorrhage requiring blood transfusion. During follow-up of 409 patients, thrombocytopenia resolved uneventfully in 277. A risk period was present in 376 cases. Among 283 with self-limiting ITP, 26 were at risk >1 month and 25 had 30 events. Among 93 patients with chronic ITP, 73 were at risk >1 month and 44 had 111 events. Events occurred with an average frequency of 0.39 per month at risk. Life-threatening hemorrhages did not occur in the first six months after diagnosis. CONCLUSION: Most children with ITP are at risk for serious bleeding for less than one month. Continuing severe thrombocytopenia is associated with little morbidity, bleeding episodes being infrequent and very rarely serious.     

Effects of COVID-19 vaccination on platelet counts and bleeding in children,adolescents, and young adults with immune thrombocytopenia

Coronavirus disease 2019 (COVID-19) vaccines rarely cause de novo immune thrombocytopenia (ITP) but may worsen preexisting ITP in adults. Whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines impact platelet counts and bleeding in children, adolescents, and young adults (C-AYA) with preexisting ITP is unknown. We report here the very limited effect of COVID-19 vaccination on platelet counts and bleeding in a single-center series of 2 C-AYA with ITP. No patient experienced worsening bleeding and only one child had a significant decrease in platelet count which improved spontaneously to her baseline without intervention. SARS-CoV2 vaccination was safe in C-AYA with ITP in this small cohort.     

Idiopathic thrombocytopenic purpura: a 10-year natural history study at the childrens hospital of alabama

Childhood idiopathic thrombocytopenic purpura (ITP) is a common disorder. However, single-institution, long-term, natural history data are limited. The objective of this paper is to review presenting features, response to therapy, and natural history of ITP treated at a single pediatric academic medical center. A retrospective chart review was made for all children (ages birth-18 years) diagnosed with ITP (ICD 287.3) and treated at the Childrens Hospital of Alabama/University of Alabama at Birmingham between 1993 and 2003. Four hundred nine patients were identified (49% male, 51% female; mean age: 5.85 years; range: 1 month-17 years). There was no seasonal variation of presentation. The mean platelet count was 19k (0-120k). Bone marrow aspiration (BMA) was performed in 72% but altered the diagnosis or therapy in no patient. Treatment consisted of corticosteroids in 256 (92% response), intravenous immunoglobulin (IVIG) in 125 (87% response), Win-Rho D in 58 (91% response), and no therapy in 71 (100% response). Response was defined as increase in platelet count to > 50k. There was no difference in response to any therapy. No patients died. One patient presented with a CNS hemorrhage at presentation, responded to therapy, and survived. Twenty-three of 409 patients (6%) experienced clinical bleeding requiring hospitalization or blood transfusion. Chronic ITP (persistence > 6 months) was noted in 99 patients (24%). Chronic patients presented at an older age (7.8 vs 5.2 years for acute only, p<0.001), and with higher platelet counts (27k vs 17k, p<0.001). The risk of chronic ITP was partially predicted by presenting platelet count > 50k and age > 10 years, or both; 50% of patients presenting with these features developed chronic ITP vs 24% overall rate. Splenectomy was curative in 30/31 (97%) patients. There was no postsplenectomy sepsis. Of 99 patients with chronic ITP, 25 responded to splenectomy, 37 resolved at a mean of 20.3 months after diagnosis (7-96 months), 36 had persistent mild thrombocytopenia (50k-125k), and 1 failed to respond to any treatment including splenectomy. Overall, 91% of cases resolved with therapy or observation. ITP is a common pediatric disease presenting at any age with low morbidity and mortality. Most cases can be managed by pediatricians without hematology referral. Several equally successful therapeutic options exist. Chronic cases present at an older age with higher platelet counts. Up to 50% of cases of chronic ITP will resolve with ongoing follow-up. The overall prognosis in childhood ITP is excellent.     

选择性脾切除术治疗儿童ITP的疗效探讨

目的探讨近年来儿童慢性特发性血小板减少性紫癜(ITP)患者行选择性脾切除术的有效性及安全性。方法收集1986年～2000年新华医院及上海儿童医学中心行选择性脾切除术治疗ITP的患儿资料,以术后血小板计数的稳定最低值判断疗效,回顾性研究其相关因素。结果16例慢性ITP患儿行选择性脾切除术,其中9例男孩,7例女孩。治愈7例(43.75%),好转5例(31.25%)。术后随访未有感染并发症发生。治愈患儿的术后血小板峰值均超过400×109/L,而其余患儿中仅2例超过400×109/L,经Fisher精确检验,两组间有显著差异(P<0.01)。结论选择性脾切除术是治疗儿童慢性ITP安全有效的方法。脾切除术后的疗效与术后血小板最高峰值相关,术后高的血小板计数峰值将提示着良好的预后。     

Relationships among bleeding severity,health‐related quality of life,and platelet count in children with immune thrombocytopenic purpura

Important outcomes for children with immune thrombocytopenic purpura (ITP) include health‐related quality of life (HRQOL) and bleeding severity. A HRQOL instrument for children with ITP, the Kids' ITP Tools (KIT), was recently validated. Secondary analysis of the KIT database was performed to determine relationships among platelet count, bleeding severity and HRQOL. Bleeding severity grade correlated with platelet count in chronic ITP but not in acute ITP. Platelet count and bleeding severity failed to have any statistically significant correlations with the KIT scores. These findings suggest that relationships among outcome measures in children with ITP, using currently available instruments, remain poorly defined. Pediatr Blood Cancer 2009;53:652–654. © 2009 Wiley‐Liss, Inc.