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.     

Misdiagnosis of chronic thrombocytopenia in childhood

PURPOSE: Children ultimately diagnosed with nonimmune chronic thrombocytopenia are often referred to pediatric hematology clinics with a provisional diagnosis of autoimmune thrombocytopenic purpura (AITP). The authors' aim was to establish in these patients the features characterizing the mechanism of thrombocytopenia. PATIENTS AND METHODS: The authors performed a retrospective review of the case records of seven children (three boys and four girls, aged 5 months to 7 years) with misdiagnosed chronic AITP referred to a single pediatric hematology center between 1990 and 2000. RESULTS: In the seven children, the suspected diagnosis on referral was AITP and the final diagnosis was inherited thrombocytopenia. Abnormalities of platelets and/or leukocyte morphology were present in all of them. Other features suggestive of inherited thrombocytopenia included a history of familial thrombocytopenia (2/7), failure of steroids and/or intravenous immunoglobulins to raise the platelet count to normal levels (5/7), and moderate increase of Indium-111 platelet turnover in the two patients tested. Platelet-associated IgG (PaIgG) was above the normal threshold in the four children tested; the direct monoclonal antibody immobilization of platelet antigens (MAIPA) test was negative in the four children tested and the serum test was positive in two boys. Bone marrow examination revealed either a normal (4/7) or an elevated (3/7) number of megakaryocytes. CONCLUSIONS: Family history and blood cell morphology analysis in experienced hands are the first steps in discriminating AITP from inherited thrombocytopenia in children with isolated chronic thrombocytopenia. In contrast, bone marrow examination and search for specific autoantibodies using the MAIPA test are of little help. An isotopic platelet life span study, when available, should be performed before considering splenectomy to exclude the diagnosis of inherited thrombocytopenia, especially when steroids and/or IgG IV administration failed to raise the platelet count.     

Gray platelet syndrome]

BACKGROUND. Gray platelet syndrome is a rare (about 40 cases published), inherited disorder characterized by a marked decrease or absence of platelet alpha-granules and platelet specific alpha-granule proteins. CASE REPORT. A boy, aged 4 years, presented with frequent ecchymoses. Acute idiopathic thrombocytopenia purpura was diagnosed because of his reduced platelet count (36,000/mm3) and recent viral infection. Intravenous gammaglobulin infusion was followed by a small rise in the platelet count (125,000/mm3). The patient was reinvestigated a few months later because of persistent thrombocytopenia and the failure of the immunologic treatment. The bleeding time was long and the platelets on blood smears appeared gray. Electron microscopy revealed numerous vacuoles and very few or no alpha-granules. Platelet aggregation and adhesion were normal, but stimulated platelets failed to liberate factor 4 and beta-thromboglobulin, while the plasma levels of beta-thromboglobulin were elevated. CONCLUSION. The frequency of gray platelet syndrome is probably underestimated in those diseases resulting in thrombocytopenia and this will continue until blood smears are thoroughly examined. Synthesis of platelet specific alpha-granule proteins seems normal; but these proteins cannot be stored as there are very few, or no alpha-granules. This abnormality could lead to increased levels of such proteins in the plasma.     

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.     

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.     

不同血小板水平儿童急性淋巴细胞白血病的临床特征及预后研究

目的 探讨儿童急性淋巴细胞白血病（ALL）初诊时不同血小板水平与预后的相关性。方法 选取采用中国儿童白血病协作组-ALL 2008（CCLG-ALL 2008）方案治疗的892例初诊ALL患儿为研究对象,按初诊时血小板水平分为血小板正常组（血小板≥ 100×10⁹/L,n=263）和血小板减少组（血小板 < 100×10⁹/L,n=629）;血小板减少组又分为（50~）×10⁹/L（n=243）、（20~）×10⁹/L（n=263）、 < 20×10⁹/L（n=123）亚组。对各组患儿的性别、年龄、免疫分型、分子生物学等临床特征与无事件生存（EFS）率、总生存（OS）率的相关性进行分析。结果 血小板正常组MLL基因重排阳性、复发率低于血小板减少组（P < 0.05）,血小板正常组10年预期EFS率高于血小板减少组（P < 0.05）,两组10年预期OS率差异无统计学意义（P > 0.05）;剔除MLL基因重排阳性患儿,血小板正常组10年预期EFS率仍高于血小板减少组（P < 0.05）,两组10年预期OS率差异仍无统计学意义（P > 0.05）。血小板 < 20×10⁹/L亚组10年预期EFS率和10年预期OS率低于血小板正常组、（50~）×10⁹/L亚组、（20~）×10⁹/L亚组（P < 0.05）;剔除MLL基因重排阳性患儿,血小板 < 20×10⁹/L亚组10年预期EFS率和10年预期OS率仍低于血小板正常组、（50~）×10⁹/L亚组、（20~）×10⁹/L亚组（P < 0.05）。结论 伴有MLL基因重排阳性的ALL患儿临床表现多为血小板减少。ALL患儿初诊时血小板水平与患儿预后相关,血小板计数正常者复发率低、预后好,血小板 < 20×10⁹/L组预后最差。     

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.     

Thrombopoietin has a primary role in the regulation of platelet production in preterm babies.

Thrombocytopenia in the first days of life, in association with evidence of reduced megakaryocytopoiesis and platelet production at birth, is common in sick preterm babies. Thrombopoietin (Tpo) is the major regulator of platelet production in adults. However, these babies have low Tpo levels at birth, suggesting that the Tpo response to thrombocytopenia may be impaired. To test this hypothesis we 1) measured Tpo levels, 2) measured circulating megakaryocyte progenitors serially over the first 12 d of life in 13 preterm babies with early onset thrombocytopenia and in 14 control babies with evidence of normal megakaryocytopoiesis, and 3) measured Tpo levels in thrombocytopenic children (n = 13). In control babies, platelet counts and progenitor numbers remained normal and Tpo levels were consistently low-d 1:160+/-23 pg/mL (mean+/-SEM), d 4/5: 154+/-18 pg/mL and d 12: 150+/-58 pg/mL. In thrombocytopenic babies, platelet counts and megakaryocyte progenitor numbers were significantly lower than controls at d 1: platelets 130+/-14 x 10(9)/L versus 255+/-20 x 10(9)/L (p < 0.001) and megakaryocyte progenitors 552 versus 3907 colonies/mL (mean, p < 0.001), and fell further to nadir on d 4/5: platelets 76+/-6 X 10(9)/L versus 259+/-21 x 10(9)/L (p < 0.001) and MK progenitors 479 versus 2742 colonies/mL (p < 0.05). Tpo levels were only slightly raised on d 1:247+/-52 pg/mL (p = 0.24), but then rose sharply by d 4/5: 425+/-75 pg/mL (p < 0.001). By d 12, platelet count, megakaryocyte progenitors and Tpo level (145+/-29 pg/mL) had returned to control levels. Tpo levels at platelet nadir in thrombocytopenic babies were significantly lower than in thrombocytopenic children: mean 425 versus 1383 pg/mL (p < 0.001). These data show that Tpo is important in platelet homeostasis in preterm babies, with a close reciprocal relationship with platelet count and progenitor numbers during thrombocytopenia. However, the increase in Tpo levels seen in these babies was modest, despite significantly impaired megakaryocytopoiesis, and when compared with that seen in children with thrombocytopenia. This offers further evidence that preterm babies have an impaired Tpo response to thrombocytopenia and suggests that recombinant human Tpo may have a role in the prevention/treatment of preterm thrombocytopenia.     

Interleukin-11 levels in healthy and thrombocytopenic neonates

Thrombocytopenia is common in sick neonates, and affected neonates have adverse outcomes compared with those without thrombocytopenia. As impaired platelet production underlies many neonatal thrombocytopenias, affected neonates are potential candidates for hemopoietic growth factor therapy. Although recombinant human (rh) thrombopoietin remains under therapeutic development, rhIL-11, which stimulates megakaryocytopoiesis and increases platelet counts after chemotherapy, is already licensed for clinical use. However, nothing is known about IL-11 in neonates. We therefore measured plasma IL-11 by ELISA in healthy term neonates, stable preterm neonates with or without thrombocytopenia, and preterm neonates with sepsis or necrotizing enterocolitis (NEC) with or without thrombocytopenia. At birth IL-11 was undetectable (<10 pg/mL) in healthy term neonates (n = 20) and 27 of 31 (87%) stable preterm neonates. Three stable preterm neonates with detectable IL-11 (mean+/-SD, 11.3 +/- 0.4 pg/mL; median, 11.6 pg/mL) suffered chorioamnionitis, the remaining neonate (IL-11, 14 pg/mL) being one of nine with early onset thrombocytopenia (present by <72 h of age). IL-11 was also measured in 58 preterm neonates with suspected sepsis or NEC. In 25 of 58, sepsis or NEC was unconfirmed and IL-11 was undetectable. By contrast, 14 of 33 with proven sepsis or NEC had elevated IL-11 (median, 14.9 pg/mL; range, 11.2-92.2 pg/mL). Of these 33 neonates, 19 developed thrombocytopenia: nine of 19 (47%) had detectable IL-11 and 10 of 19 (53%) did not (p > 0.05). Although its role in platelet production in neonates remains unclear, these data suggest that IL-11 is involved in the endogenous cytokine response to sepsis or NEC in preterm neonates. Further studies of IL-11 in neonates are warranted to assess its role both in platelet production and in mediation of the endogenous inflammatory response.     

Fetal and neonatal thrombopoietin levels in alloimmune thrombocytopenia

Thrombopoietin (Tpo) is the main hematopoietic growth factor for platelet production. Plasma Tpo levels in autoimmune thrombocytopenic patients are normal or slightly elevated. Although thrombocytopenia exists, Tpo levels are not increased because the produced megakaryocytes and platelets can bind circulating Tpo, thereby normalizing Tpo levels. In this study, plasma samples from fetuses and neonates with neonatal alloimmune thrombocytopenia (NAIT), a different form of immune thrombocytopenia, were measured. Umbilical cord samples from 50 fetuses before treatment because of severe thrombocytopenia and 51 fetuses after treatment, and peripheral blood samples of 21 untreated newborns with NAIT were analyzed. As controls, plasma Tpo levels were determined in 21 umbilical cord samples of 14 nonthrombocytopenic fetuses with hemolytic disease resulting from red blood cell alloimmunization and in umbilical cord samples of 51 healthy newborns. The values were also compared with the plasma Tpo levels in 193 healthy adults. Mean Tpo levels from the groups of fetuses and neonates, including both NAIT and control plasma, were slightly but significantly elevated compared with levels in healthy adults. Tpo levels in NAIT samples were not significantly different from the levels in hemolytic disease samples or in samples from healthy newborns. Thus, as in autoimmune thrombocytopenic patients, normal Tpo levels are present in NAIT patients.     

Neonatal alloimmune thrombocytopenia associated with anti-human platelet antigen-3a antibody

A sister and brother with neonatal alloimmune thrombocytopenic purpura (NAITP) caused by maternal anti-human platelet antigen (HPA)-3a are reported. The children had transient severe thrombocytopenia in the newborn period, and were treated with intravenous γ-globulin and platelet concentrates from random donors. Although the sister had intracranial hemorrhage on day 2 postnatally, the development of the child has been normal and no neurological sequelae have been observed. The brother only had bloody stool when the platelet count was low, and did not have severe hemorrhagic manifestations. The diagnosis of NAITP was made by the sera from the mother, which contained anti-HPA-3a antibody directed against platelets of the children. The rate of recurrence might be high in this family, because the father of the patients was found to be homozygous for the HPA-3a gene.     

Thrombocytopenia: a complication of Kawasaki disease

Thrombocytopenia was observed in 10 (2.0%) of 486 children with Kawasaki disease. In nine of the ten, the minimal paltelet count of 94000±38000 (SD)/mm³ was seen on day 6.8±2.2 (SD) of illness and the platelet counts were elevated to the normal level in 1–2 weeks. Thrombocytopenia in the nine appeared to be caused via coagulation-mediated platelet consumption, while the remaining child was diagnosed as having idiopathic thrombocytopenic purpura. One of the two who had severe coagulation-mediated thrombocytopenia of less than 50000/mm³ developed coronary aneurysms persisting over 1 year.Abbreviations APTT Activated partial thromboplastin time - ESR Erythrocyte sedimentation rate - FDP Fibrinogen/fibrin degradation products - ITP Idiopathic thrombocytopenic purpura - PT Prothrombin time - SD Standard deviation     

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-associated immunoglobulin G in childhood idiopathic thrombocytopenic purpura

Platelet-associated IgG was studied in children with acute and chronic ITP and in patients with thrombocytopenic SLE, using the microtiter solid-phase radioimmunoassay. Of the children with acute ITP, 85% had elevated PAIgG levels. The degree of elevation of PAIgG at onset of disease did not correlate with the development of chronicity. Of the children with acute ITP, clinically and hematologically indistinguishable from the rest, 15% had normal PAIgG values. All of 22 children with chronic ITP had elevated PAIgG values. Although there was good correlation between the platelet count and the PAIgG value in children with chronic ITP, the association was not as striking in those with acute ITP; thus, factors in addition to the level of PAIgG may contribute to the thrombocytopenia in the latter group. Patients with SLE and thrombocytopenia had higher values of PAIgG than would be predicted from the platelet count; the PAIgG value is probably not the only factor determining the degree of immune thrombocytopenia.     

Chronic consumption coagulopathy due to an occult splenic haemangioma: Kasabach-Merritt syndrome

We report an 11-year-old girl with a 2-year histor of bruising associated with thrombocytopenia and dysfibrinogenaemia. On admission she presented with a large subcutaneous haematoma and splenomegaly and was severely anaemic. Laboratory investigations revealed signs of consumption coagulopathy. Radiological examination showed splenic, retroperitoneal and intra-ossal haemangiomas. After splenectomy, platelet count and coagulation parameters returned to normal.Conclusion Contrary to widely held views, occult visceral haemangioma can lead to Kasabach-Merritt syndrome beyond infancy and is not necessarily associated with visible cutaneous haemangioma. It should be included in the differential diagnosis of chronic thrombocytopenia at any age. Early determination of fibrinogen degradation product levels is advised in order to detect an underlying chronic consumption coagulopathy prompted by an extensive search for multifocal liaemangioma.     

Incidence of thrombocytopenia in infants born to mothers with idiopathic thrombocytopenic purpura

Abstract Neonatal thrombocytopenia related to maternal idiopathic thrombocytopenic purpura (ITP) is reportedly uncommon but may have severe complications. The present report reviews records of 15 infants born to mothers with ITP during a 10-year period, and the incidence of neonatal thrombocytopenia and the risk of hematological complications is examined. Severe thrombocytopenia (platelets < 50 000/μL) was seen in three infants despite successful therapy with high-dose gamma globulin prior to delivery, which elevated maternal platelet counts. Although the platelet counts of these three infants fell to < 10 000/μL, none had severe complications. Moreover, no infants required treatment such as adrenocorticosteroids, platelets transfusion, or high doses of gamma globulin. No maternal markers predicted the degree of neonatal thrombocytopenia. The risk of complications arising from neonatal thrombocytopenia is low, but careful observation is required for the thrombocytopenic newborn of ITP mothers even when the infant has no bleeding complications at delivery.     

Danaparoid sodium (Orgaran) in four children with heparin-induced thrombocytopenia type II

We report on four children with heparin-induced thrombocytopenia type II. In three patients, therapy with unfractionated heparin was associated with development of cardiac thrombi or with thrombosis progression up to the inferior vena cava or with aggravation of peripheral arterial occlusion. In the fourth child, the disease was recognized early on, and no complication occurred. Heparin-induced thrombocytopenia type II was confirmed by heparin-induced platelet activation assay and/or heparin/platelet factor 4-ELISA. Concomitant elevated antiphospholipid antibodies were seen in all patients. Danaparoid sodium applied at a dosage of between 1.2 and 7.1 U/kg/h stopped the disease progression in each patient. Three children had a clinical recovery with partial recanalization, but for the child with peripheral arterial occlusion disease, amputation of some of the toes became necessary. Conclusion: Our data indicate that heparin-induced thrombocytopenia type II is a potential lifethreatening disease in children and danaparoid sodium is beneficial in this age group.     

High-dose steroids in childhood acute idiopathic thrombocytopenia purpura

Nine newly diagnosed, previously untreated children (mean age: 4.2 years, range: 1-9 years) with severe acute idiopathic thrombocytopenia purpura (mean platelet count: 5.8 X 10(9)/L, range: 1-12 X 10(9)/L) were treated with high-dose steroids (prednisone 4-8 mg/kg/day). Steroid dose was based on platelet count at presentation: Group I (platelets less than 5 X 10(9)/L) was started on 8 mg/kg/day; Group II (platelets 5-15 X 10(9)/L) received 6 mg/kg/day. All patients had serologic and histologic evidence of acute idiopathic thrombocytopenia purpura. On this protocol, it took a mean number of 1.9 days (1-3 days) to reach a platelet count of at least 20 X 10(9)/L and 9.2 days (3-26 days) to reach a normal platelet count. No significant toxicity was observed except for weight gain ranging from 3-10% and mild behavioral problems. Both groups were on high-dose steroids (4-8 mg/kg/day) for 7.3 +/- 2.1 days. Only one patient had a brief relapse to a platelet count of 18 X 10(9)/L while on therapy (day 14), but responded promptly to an increase in prednisone dose. Presently, all nine patients are in remission and have not required maintenance medication.