Pulsed high-dose dexamethasone therapy in children with chronic idiopathic thrombocytopenic purpura

The effectiveness of pulsed high-dose oral dexamethasone therapy in children with refractory chronic idiopathic thrombocytopenic purpura (ITP) is evaluated. Thirteen children with severe chronic ITP were enrolled in the study from an outpatient pediatric hematology clinic (ages 2-14 years), 5 boys and 7 girls. They did not maintain a response to other forms of therapy (IVIg, Anti-D, conventional steroids, danazol) and one girl relapsed after splenectomy. Dexamethasone was administered orally at a dosage of 40 mg/M2/day (maximum 40 mg/day) for 4 consecutive days. The cycle was repeated once a month for 6 months. The immediate response to therapy was excellent as the mean platelet count at day 1 was 15 x 10(9)/L, while mean platelet count at day 4 was 158 x 10(9)/L. At the end of 6 cycles 3 patients maintained a platelet count of >150 x 10(9)/L and 4 patients showed partial response. At the end of the first year and second year (12 and 24 months after onset of treatment) 3 patients still had complete response, 3 patients had partial response, and 7 patients were failures. Six of the failures underwent splenectomy and one was shifted to dapsone, had no response, and refused splenectomy. Side effects were tolerable. They included bloating, nausea, vomiting, insomnia, anxiety, and depression, and transient glucosuria; however, they were not severe enough to discontinue the cycles. Mean duration of illness prior to start of dexamethasone was not significantly different in between responders and nonresponders. Dexamethasone given orally in high doses is an effective drug in achieving short-term platelet responses. Long-term remission is obtained in nearly half the patients with well-established chronic ITP. Its effectiveness in almost half the patients, minimal side effects, and low cost indicate that this treatment should be considered in patients with chronic ITP who do not tolerate the disease well before considering splenectomy.     

Clinical characteristics of chronic idiopathic thrombocytopenia in Chinese children

PURPOSES: Clinical course and treatment outcome of childhood chronic ITP are quite variable in the literature. We report in the current paper our observation on the clinical behavior of chronic ITP in Chinese children. PATIENTS AND METHODS: We performed a retrospective review (Jan. 1990 to Dec. 2000) of children having low platelet count (plt <150 x 10(9)/L) for more than 6 months without identifiable cause. The indication for treatment was plt < or =20 x 10(9)/L. Remission is defined as plt > or =150 x 10(9)/L. RESULTS: Thirty-four children were identified within these 11 years. Their median age at diagnosis was 6.7 years (range from 0.4 to 16.8 years). The M:F ratio was 16:18. Bone marrow aspiration was performed in 30/34 cases. The median plt count at presentation was 24 x 10(9)/L (range 2 to 135 x 10(9)/L). Fourteen of 34 (41%) children eventually achieved durable remission. The chance of remission at 5 years was 66.62% with a median follow-up time of 5.86 years (range 0.72 to 10.41 years). Concerning therapy, 17/34 (50%) required no treatment while for the remaining 17, treatment included steroid (n = 16), IVIG (n = 7) or splenectomy (n = 3). In spite of temporary improvement in most, treatment induced prolonged complete remission (plt >150 x 10(9)/L) in only 2 patients. Twenty of 31 tested had abnormal immune marker(s) at presentation but none evolved into specific autoimmune disease later on. There was no correlation between the remission status, response to treatment, and the presence of autoimmune markers. CONCLUSION: About half of our chronic ITP patients achieved remission within 5 years. Medical treatment does not seem to alter the natural course of the disease but induced a transient response in most cases. Positive autoimmune markers are common among chronic ITP patients and have no significance in predicting outcome.     

Elective splenectomy in children with idiopathic thrombocytopenic purpura

PURPOSE: The aim of this study was to review the safety and efficacy of elective splenectomy in children with idiopathic (immune) thrombocytopenic purpura (ITP). METHODS: The authors reviewed the medical records of children with ITP treated with elective splenectomy at Children's Medical Center of Dallas since 1961. Indication for splenectomy was symptomatic thrombocytopenia unresponsive to medical management. RESULTS: Thirty-eight evaluable patients who had elective splenectomy for ITP were identified. Twenty-one (55%) were girls and 17 (45%) were boys. Twenty-two had splenectomy since January 1990. Age at diagnosis ranged from 6 months to 15.9 years (median 9 years), and age at splenectomy ranged from 3.6 to 16.4 years (median 11.8). Laparoscopic splenectomy was performed in 11 patients. No patient died and only one (2.6%) had postoperative hemorrhage. There were no other complications related to surgery. No cases of postsplenectomy sepsis were observed. At follow-up ranging from 1 month to 19.9 years (median 2.1 years), 29 patients (76.3%) had a normal platelet count (>150 x 109/L) and 4 (10.5%) had a platelet count between 50 and 150 x 109/L. Only two of the five (13.2%) remaining patients who continued to have a platelet count less than 50 x 109/L had hemorrhagic manifestations necessitating intermittent therapy with corticosteroids. CONCLUSION: Laparoscopic or open splenectomy is a safe and effective procedure for children with chronic or refractory ITP and should be considered when medical management fails or causes excessive toxicity.     

Interferon-alpha therapy in idiopathic thrombocytopenic purpura

BACKGROUND: Acute idiopathic thrombocytopenic purpura (ITP) represents the most frequent hemorrhagic diathesis in childhood. Up to 30% of patients with ITP are regarded as refractory to standard therapy. The rare mortality from acute ITP in childhood is almost exclusively due to intracranial hemorrhage. This complication occurs in less than 1% of ITP patients. This study was designed to evaluate the effect of alpha-interferon (IFN-alpha) in eight patients whom did not respond to conventional therapy. METHOD: In spite of conventional therapies, the patient whose platelet count could not be increased to 50;10(9)/L were accepted as refractory ITP. Eight of these patients whose platelet count lower than 20;10(9)/L were included in the prospective cohort study. Interferon alpha 2b 5 MU/m(2) was administered subcutaneously three times a week, totalling 12 times in a month. According to the platelet count on the 28th day of therapy, we grouped the patients into three categories. After 60 days, the survey was re-evaluated according to the platelet count. RESULTS: The mean age of children was 3.5+/-2.5 (ranged between 3.5 and 9) years. Six of them were boys and two were girls. There was no response in one patient, partial response in one, and good response in six patients on the 28th day of therapy. The maximum rise in platelet count was observed from 7 to 14 days after the initiation of interferon. The median platelet count which was 15+/-5;10(9)/L before therapy, raised to 60+/-12;10(9)/L after therapy. However, on the 60th day of therapy, there were only two patients who had a platelet count over 100;10(9)/L. CONCLUSION: In our study, we did not observe the long-term benefit of IFN-alpha therapy in refractor ITP in childhood. However, in good responding patients, platelet levels were increased in a short time. Alpha-interferon may be alternative therapy for patients whom had a platelet count below 20;10(9)/L and not responding to standard therapy, or for patients whom immunosuppressive therapy is contraindicated.     

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。     

Long-term outcome of chronic idiopathic thrombocytopenic purpura in children

OBJECTIVES: Children with chronic idiopathic thrombocytopenic purpura (ITP) generally have a favorable outcome, but it is not known whether there are any prognostic factors to predict outcome. The objectives of this study were to assess the spontaneous remission rate and the prognostic significance of age, gender, initial platelet count, initial treatment, and response to treatment. METHODS: In this retrospective review of 62 consecutive children with chronic ITP, 37 were girls and 27 were 10 years of age or older (median age 9 years; range, 0.75-19). RESULTS: Thirty-five patients (56%) achieved spontaneous remission (remission without splenectomy), 30 of them (48%) within 4 years from diagnosis. Twenty-eight (45%) were complete remissions (platelet counts of >/=100,000) and 7 (11%) were partial remissions (50,000-99,000). There was no significant difference in the spontaneous remission rate between the younger (<10 years) and older children (55.8% vs. 57.1%, P = 0.95) or between boys and girls (56% vs. 56.7%, P = 0.98). Similarly, platelet count at initial diagnosis, initial therapy, or response to initial therapy did not have any prognostic significance. All 14 patients who underwent splenectomy achieved complete remission. CONCLUSIONS: More than 50% of children with chronic ITP achieve spontaneous remission. Age, gender, platelet count at initial diagnosis, initial treatment, and response to initial treatment do not have any prognostic significance toward the outcome of chronic ITP.     

Randomized study of IVIg and high-dose dexamethasone therapy for children with chronic idiopathic thrombocytopenic purpura

PURPOSE: To investigate whether pulsed high-dose dexamethasone is more efficacious than intravenous immunoglobulin (IVIg) as treatment of symptomatic chronic idiopathic thrombocytopenic purpura (ITP) in childhood. METHODS: In a 2:1-randomized study, 23 children with chronic ITP received dexamethasone (0.6 mg/kg per day for 4 consecutive days once monthly for 6 months, n = 15) or IVIg (800 mg/kg intravenously once monthly for 6 months, n = 8). After four courses of treatment a crossover was offered to nonresponders. A total of 20 children received dexamethasone and 11 received IVIg. RESULTS: One of the 8 IVIg patients and 2 of the 15 dexamethasone patients achieved complete response, defined as a platelet count of at least 150 x 10(9)/L for more than 3 months without treatment. Two of the 15 dexamethasone patients achieved partial response, defined as a platelet count of at least 30 x 10(9)/L for more than 3 months without treatment. One of the 8 IVIg patients and 5 of the 15 dexamethasone patients discontinued treatment. Five patients crossed over from IVIg to dexamethasone (one complete response) and three from dexamethasone to IVIg (none responded). In summary, 5 of the 20 dexamethasone patients achieved a complete or partial response and 1 of the 11 IVIg patients achieved a complete response. Platelet counts of at least 30 x 10(9)/L by day 3 were reached in 9 of the 12 (75%) dexamethasone patients and all 8 (100%) IVIg children using available data. Five years after study completion, two of the three children who achieved a complete response and one of the two with a partial response to dexamethasone were in remission, as was the child with a complete response to IVIg. CONCLUSIONS: Treatment with pulsed high-dose dexamethasone is not always effective in children with chronic ITP, but it is worth trying in severe symptomatic chronic childhood ITP.     

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.     

Combination therapy for refractory idiopathic thrombocytopenic purpura in adolescents

PURPOSE: To investigate combined immunosuppressive therapy with vincristine, methylprednisolone, and prolonged cyclosporine in adolescents with refractory idiopathic thrombocytopenic purpura (ITP). PATIENTS AND METHODS: Ten adolescent patients with ITP refractory to previous medical management, including gluco-corticosteroid, intravenous immunoglobulin or anti-Rh (D) IgG, or splenectomy, were treated with combination immunosuppressive therapy at the University of Michigan between 1997 and 2001. Therapy consisted of weekly doses of vincristine 1.5 mg/m intravenous push (IVP) (maximum dose 2 mg), weekly methylprednisolone 100 mg/m IVP, and cyclosporine (CSA) 5 mg/kg orally twice daily (goal: CSA trough of 100-200 mg/mL). Vincristine and methylprednisolone were given weekly until the platelet count was greater than 50,000/mm for a minimum of 2 doses and a maximum of 4 doses. CSA was continued until the platelet count was normal for 3 to 6 months. RESULTS: Seven patients had continuous complete responses (platelet count normal after cessation of CSA), a median of 13 months (9-37 months) since completion of therapy. One patient had a partial response (platelet count 80-120 x 10 /L off CSA for 3 months). Two patients were nonresponders (platelet count <40 x 10 /L), one of whom had all therapy discontinued after 2 weeks due to peripheral neuropathy. The median time to response was 7 days (range 7-67 days). CSA was administered for a median of 4 months (range 0.5-19 months). CONCLUSIONS: A combination immunosuppressive approach that includes prolonged cyclosporine therapy may be promising for refractory ITP and is associated with sustained disease remissions in some patients.     

PULSED HIGH-DOSE DEXAMETHASONE THERAPY IN CHILDREN WITH CHRONIC IDIOPATHIC THROMBOCYTOPENIC PURPURA

The effectiveness of pulsed high-dose oral dexamethasone therapy in children with refractory chronic idiopathic thrombocytopenic purpura (ITP) is evaluated. Thirteen children with severe chronic ITP were enrolled in the study from an outpatient pediatric hematology clinic (ages 2-14 years), 5 boys and 7 girls. They did not maintain a response to other forms of therapy (IVIg, Anti-D, conventional steroids, danazol) and one girl relapsed after splenectomy. Dexamethasone was administered orally at a dosage of 40 mg/M2/day (maximum 40 mg/day) for 4 consecutive days. The cycle was repeated once a month for 6 months. The immediate response to therapy was excellent as the mean platelet count at day 1 was 15 &#50 10 9 /L, while mean platelet count at day 4 was 158 &#50 10 9 /L. At the end of 6 cycles 3 patients maintained a platelet count of >150 &#50 10 9 /L and 4 patients showed partial response. At the end of the first year and second year (12 and 24 months after onset of treatment) 3 patients still had complete response, 3 patients had partial response, and 7 patients were failures. Six of the failures underwent splenectomy and one was shifted to dapsone, had no response, and refused splenectomy. Side effects were tolerable. They included bloating, nausea, vomiting, insomnia, anxiety, and depression, and transient glucosuria; however, they were not severe enough to discontinue the cycles. Mean duration of illness prior to start of dexamethasone was not significantly different in between responders and nonresponders. Dexamethasone given orally in high doses is an effective drug in achieving short-term platelet responses. Long-term remission is obtained in nearly half the patients with well-established chronic ITP. Its effectiveness in almost half the patients, minimal side effects, and low cost indicate that this treatment should be considered in patients with chronic ITP who do not tolerate the disease well before considering splenectomy.     

Autoimmune thrombocytopenic purpura: maternal and fetal disease.

We have followed up 63 pregnancies in women with autoimmune thrombocytopenic purpura (ATP). Of these, 15 were previously splenectomized. The characteristics of the sample can be summed up as follows: average age 27 years (17-41); platelets at the beginning of pregnancy, mean 129.5 x 10(9)/l (range 16-488); platelets at delivery, mean 133 x 10(9)/l (range 8-477); PA-IgG at delivery, mean 320 ng IgG/10(7) platelets (range 10-1000); SPB-IgG at delivery, mean 262 ng IgG/10(7) platelets (range 10-1000). There were 30 spontaneous deliveries and 33 cesarean sections. Forty-two newborns had a platelet count within the normal range while nine had a platelet count less than or equal to 150 x 10(9)/l, while six had less than or equal to 100 x 10(9)/l and a further six less than or equal to 50 x 10(9)/l. The aim of this study is the evaluation of maternal risk and of possible feto-neonatal thrombocytopenia at birth. In this regard, the following parameters were considered: previous maternal splenectomy; the platelet count at the beginning of pregnancy; the platelet count and the titres of PA-IgG and SPB-IgG at delivery. Preliminary statistical evaluation of these parameters enabled us to identify a risk score. From this it was possible to obtain an optimum management of the final stage of pregnancy regarding the therapeutic approach and the timing of delivery.     

Immune thrombocytopenic purpura in childhood in Norway: a prospective, population-based registration

A prospective, population-based registration of children with immune thrombocytopenic purpura (ITP) was performed in Norway in 1996 and 1997. Ninety-two cases were identified, indicating an incidence of 5.3 per 100,000 children under 15 years. The sex ratio (female/male) was 1.2/1. Fifty-six percent presented with cutaneous signs only. The lowest platelet count was < 20 x 10(9)/L in 91%. In spite of mild bleeding symptoms, medical treatment was given in 68%, in most cases (57/63) with intravenous immunoglobulin. A total of 41/44 patients with platelet counts of < or = 5 x 10(9)/L were treated, regardless of whether they had mucous bleedings or not. Eighteen percent had platelet counts < 150 x 10(9)/L at 6 months, and 9% at 12 months following diagnosis. One patient with therapy-resistant chronic ITP died 16 months after diagnosis from an anesthesia complication related to profound epistaxis. This study shows a relatively high incidence. As in other studies, there was a tendency to treat platelet counts rather than bleeding symptoms.     

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.     

Clinical course of children with immune thrombocytopenic purpura treated with intravenous immunoglobulin G or megadose methylprednisolone or observed without therapy

The authors compared the prognosis in 50 children with acute immune thrombocytopenicpurpura (ITP) who received intravenous immunoglobulin G (IVIG), megadose methylprednisolone (MDMP), or no therapy. Twenty-six children were observed with no therapy, 12 children received IVIG, and 12 children received MDMP. The percentage of the patients whose platelet counts increased at a level of > 20 x 10(9)/L and > 50 x 10(9)/L at 3 days after starting therapy was significantly higher in both IVIG and MDMP groups than in the no therapy group (p < .01), but there was no significant difference at 10 and 30 days after initiation between the 3 groups (p > .05 in each comparison). This result suggested that therapy does not increase the rate of recovery but shortens the duration of thrombocytopenia in the first days. Management derision in ITP is made on clinical condition rather than on platelet count and no treatment options is to be preferred even in the face of mucosal bleeding. If the patient has extensive bleeding and the decision is to treat, both IVIG and MDMP are equally effective in providing a safe platelet level early on.     

Use of romiplostim for primary immune thrombocytopenia in children

Very little has been published on the use of romiplostim to treat primary immune thrombocytopenia (ITP), refractory to previous treatments, in children. The objective of this study was to determine its efficacy and safety in pediatric patients in a university general hospital. Retrospective, longitudinal observational study of pediatric patients on treatment with romiplostim. The principal efficacy variable was platelet count. Safety was evaluated by recording possible adverse reactions to the medication, monitoring the appearance of thrombosis, thrombocytopenia during dose reduction, hemorrhage, and myelodysplastic syndromes. Three patients in the authors' center have been treated with romiplostim (subcutaneous [SC], initial dose: 1 μg/kg/week) for ITP refractory to various treatments: 1 with newly diagnosed ITP and 2 with chronic ITP. Patients were followed up for 27 to 39 weeks after starting treatment. Responses were achieved in 7 to 28 days, and complete responses were maintained for 37% to 91% of the follow-up period, with median platelet counts between 40 × 10(3)/μL and 215 × 10(3)/μL. The adverse reactions observed during follow-up were headache and asthenia in one patient and mucocutaneous bleeding after dose suspension in another one. With regard to effectiveness, the response in the 3 patients was varied. The drug was considered to be safe, as there were only mild adverse reactions. Although further studies and long-term follow-up are required, these results show that romiplostim could be considered an alternative to immunosuppressive therapies, such as rituximab, or splenectomy in refractory 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.     

Giant platelet disorders in African-American children misdiagnosed as idiopathic thrombocytopenic purpura.

A retrospective chart review of six African-American children with a diagnosis of macrothrombocytopenias (MTCP) was performed to evaluate the accuracy of their diagnosis. The following was diagnosed in the six children with MTCP: Fechtner syndrome (two children), Sebastian syndrome (one child), and unnamed MTCP (three children). In five families, chronic idiopathic thrombocytopenic purpura (ITP) was diagnosed in the propositus, which resulted in therapy using steroids, intravenous immunoglobulin (IVIG), and in one case splenectomy. Bleeding symptoms were generally mild. All six patients had thrombocytopenia ranging from 10 to 125 x 10(9)/L with mean platelet volume of 8 to 20 fL. Bleeding times were abnormal in two of three patients, and platelet aggregation was abnormal in three of four patients tested. Bone marrow aspirates were reported as increased megakaryocytes in the three patients on whom the procedure was performed. Ultrastructural morphology of platelets and leukocytes was performed in all six patients demonstrating giant platelets in all six patients and leukocyte inclusions in three patients. Differentiating MTCP from the more common ITP can be difficult but important in avoiding unnecessary diagnostic studies and potentially harmful therapy associated with ITP.     

Initial bone marrow aspiration in childhood idiopathic thrombocytopenia: decision analysis

PURPOSE: Bone marrow aspiration (BMA) is routinely performed before starting steroid therapy in children with idiopathic thrombocytopenia, primarily to rule out leukemia. METHODS: A decision tree for the initial management of a child older than age 6 months, presenting with idiopathic thrombocytopenia, without blasts on the peripheral smear was constructed. The three strategies are: 1) initial BMA in all patients; 2) initial BMA only in patients at high risk; and 3) empiric therapy for all patients without initial BMA. High-risk criteria include any of: platelet count >50 x 10(9)/L; hemoglobin <100 g/L (age younger than 12 months) or <110 g/L (age older than 12 months): white blood cell count <5 x 10(9)/L (younger than 6 years) or <4 x 10(9)/L (older than 6 years); or absolute neutrophil count <1.5 x 10(9)/L (younger than 6 years) or <2 x 10(9)/L (older than 6 years). The results are expressed as quality-adjusted life years (QALYs), a measure that estimates the overall life expectancy in years for patients receiving a particular treatment strategy, corrected for the patient's quality of life. RESULTS: The base case results are: 1) BMA all = 69.649 QALYs; 2) high-risk BMA = 69.652 QALYs; and 3) empiric therapy = 69.644 QALYs. These results indicate a three-way toss-up because there is less than a 4-day quality-adjusted difference (0.01) between strategies. CONCLUSION: This study indicates that the initial BMA does not significantly change the overall QALYs of a child presenting with thrombocytopenia and, consequently, is not mandatory in every patient before starting steroids.     

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.     

Effects of oxygen-induced lung damage on megakaryocytopoiesis and platelet homeostasis in a rat model

The association between lung injury and thrombocytopenia was investigated by comparing the megakaryocyte and platelet counts, and platelet activation using P-selectin as a marker, between the prepulmonary (right atrial) and postpulmonary (left atrial) blood in adult and neonatal (preterm and term) rats with and without hyperoxic lung injury. In the healthy controls, the postpulmonary blood had lower megakaryocyte count (prepulmonary versus postpulmonary: Preterm: 8.7[0.6] versus 3.9[0.3] per ml, p < 0.001; Term: 8.7[1.1] versus 2.6[0.4] per ml, p < 0.001; Adult: median [interquartile ranges]: 2.5[1.0, 5.0] versus 1.0[0, 3.0] per ml, p < 0.001), higher platelet count (prepulmonary versus postpulmonary: Preterm: 491.2[11.1] x 10(9)/L versus 595.1[10.2] x 10(9)/L, p < 0.001; Term: 472.5[19.9] x 10(9)/L versus 579.3[26.2] x 10(9)/L, p < 0.001; Adult: 513.9[31.5] x 10(9)/L versus 664.7[28.8] x 10(9)/L, p < 0.001), but similar P-selectin expression. In contrast, the lung-damaged animals did not show any such differences in either megakaryocyte or platelet count, but P-selectin expression was greater in the postpulmonary blood (prepulmonary versus postpulmonary: Preterm: 38.7[3.9] versus 56.4[4.9]% platelets, p = 0.02; Term: 40.9[2.0] versus 54.0[4.2]% platelets, p = 0.002; Adults: 30.0[3.6] versus 49.1[4.7]% platelets, p = 0.003). Peripheral platelet and intra-pulmonary megakaryocyte counts in the lung-damaged rats were significantly lower than those in their respective controls. Intra-pulmonary thrombi or platelet aggregation were detected in the lung-damaged rats but not in the controls. These findings showed that hyperoxic lung damage reduced circulating platelets through (1) failure of the lungs to retain and fragment megakaryocytes to release platelets, and (2) platelet activation leading to platelet aggregation, thrombi formation and platelet consumption. The magnitude of platelet reduction was physiologically significant, as demonstrated by higher counts of megakaryocyte colony forming units in the bone marrow culture of the animals in the hyperoxia group when compared with the controls.