Detection of platelet-associated IgG in chronic immune thrombocytopenic purpura using antibody-coated polyacrylamide beads

Summary Platelet-associated IgG (PAIgG) was detected by means of anti-human IgG coated polyacrylamide beads (Immunobeads) technique in 32 patients with chronic ITP. Both a direct test (with in vivo sensitized platelets) and an indirect test (with in vitro loaded platelets) were carried out. The percent of rosette forming beads was both in the direct test (41.2%) and in the indirect test (32.6%) significantly higher in the cases of chronic ITP patients than in the controls (2.5% and 3.2%, respectively). These results confirm the diagnostic value of this new, relatively simple and rapid method in routine clinical practice.     

The place of intravenous immunoglobulin (IgG i.v.) therapy in thrombocytopenia

Summary Acute ITP following infection in children has a high rate of spontaneous remission. Since the platelet count is not uncommonly profoundly depressed, ITP is associated with a mortality of around 1%. The aim of treatment in ITP is to prevent bleeding. As a rule, this can only be achieved by normalizing the platelet count. Intravenous immunoglobulin offers certain advantages over conventional steroid therapy. Moreover, two out of three patients with chronic ITP respond to IgG i.v. The characteristic features of ITP in pregnancy, thrombocytopenia in babies born to mothers with ITP and neonatal isoimmune thrombocytopenia are discussed.     

Platelet production rate predicts the response to prednisone therapy in patients with idiopathic thrombocytopenic purpura

The predictive value of clinical and platelet kinetic parameters for treatment outcome in idiopathic thrombocytopenic purpura (ITP) was investigated in 75 patients with platelets ≤20 × 10⁹/L. The platelet kinetic studies showed that the platelet production rate (PPR) was decreased (<100 × 10⁹/day), normal, or increased (>355 × 10⁹/day) in 33%, 48%, and 19% of patients, respectively. All patients started with prednisone at diagnosis (1 mg/kg/day). Initial complete and partial response (CR/PR) rate was 84% and a durable CR/PR (≥6 months without treatment) was attained in 44% of the patients. Durable CR/PR was noticed in 64% of the patients with decreased PPR during a median follow-up time without treatment of 81 (range 18–92) months, compared to 34% of the patients with normal or increased PPR during a median follow-up time without treatment of 141 (range 10–284) months (p = 0.03). Splenectomy was performed in 32% of patients with decreased PPR and in 62% of patients with normal or increased PPR (p = 0.03). In conclusion, ITP patients with suppressed PPR have a significant higher durable CR/PR rate to prednisone therapy and are less frequently exposed to splenectomy than those with a normal or increased PPR. Financial support was provided by a grant from the J.K. de Cock Stichting.     

Relative importance of total versus external platelet-associated IgG

Summary We present measurements of total platelet-associated immunoglobulin G following platelet lysis (PAIgG tot) and surface-restricted IgG (PAIgG ext) on intact, gel-filtered platelets from 36 normal human donors and 9 patients with human immunodeficiency virus (HIV) infection (CDC stages IIb–IV). For this purpose, an indirect micro ELISA technique was developed involving competition between PAIgG and solid-phase absorbed IgG for fixation of conjugated anti-human IgG antibody. In normal donors, the mean values of PAIgG tot was 8.3±7.4 (mean ±2 SD) and of PAIgG ext 4.2±4.4 fg/platelet. In HIV-infected subjects, PAIgG tot was 37.2±62.8 and PAIgG ext 17.1±23 fg/platelet. In healthy subjects the comparison of individual levels of PAIgG tot and PAIgG ext revealed a significant correlation (r:0.763; p: 0.003). These results are compared to those which have been reported in the literature. In addition, the major immunopathological mechanisms considered responsible for immune-mediated idiopathic thrombocytopenic purpura are discussed.Presented at the International Workshop on ITP, August 26 and 27, 1988, Lucerne, Switzerland     

Treatment of refractory chronic idiopathic thrombocytopenic purpura with high dose intravenous immunoglobulin

Summary Three patients with a history of chronic idiopathic thrombocytopenic purpura stretching back over 20 years are reported. Despite splenectomy and immunosuppressive therapy satisfactory control of their disease has not been achieved. They had remained refractory to all therapeutic manoeuvres with corticosteroids and immunosuppressives for years with thrombocyte counts between 5,000 and 25,000/l and the concommitant risk of bleeding.This report describes the treatment of bleeding complications in these patients with high dose intravenous immunoglobulin; the peripheral blood thrombocyte count increased in all three patients from subnormal towards normal, but 2 to 4 weeks later returned to its initial low value.During the therapeutically induced raised thrombocyte count a normal bleeding time and only a moderate inhibition of thrombocyte adhesion and aggregation was observed resulting in reasonable haemostasis. High dose intravenous immunoglobulin is therefore a practical method for the control of bleeding complications in patients with refractory chronic idiopathic thrombocytopenic purpura. A clear explanation for its mode of action has not been found — the lymphocyte subpopulations remained unchanged and immunoglobulin production in vitro during the course of treatment was only minimally decreased.     

联合使用免疫抑制剂对难治性ITP患者巨核细胞相关IgG水平影响及疗效分析

目的：探讨联合使用免疫抑制剂对难治性 ITP 患者巨核细胞相关 IgG 水平的影响及疗效。方法将18例难治性 ITP 患者随机分为联合治疗组和单药治疗组。联合治疗组先予2至3种静脉药物治疗3～5d,血小板值上升后联合使用2至3种不同组合的免疫抑制剂;单药治疗组先予甲基强的松龙或静脉免疫球蛋白滴注3～5d,血小板值上升后单用一种免疫抑制剂治疗。维持治疗3～6个月,随访4～24个月。运用免疫荧光法观察上述对象治疗前后巨核细胞相关IgG 情况。结果两组对象治疗后巨核细胞相关 IgG 水平均明显降低,且联合治疗组明显低于单药治疗组,差异有统计学意义（P 〈0.05）;联合治疗组总有效率88.9%,高于对照组的33.3%,差异有统计学意义（P 〈0.05）。结论联合使用免疫抑制剂对难治性 ITP 患者巨核细胞相关抗体水平有明显降低作用,同时能取得较好的临床疗效。     

妊娠合并特发性血小板减少性紫癜对胎儿血小板的影响

目的探讨妊娠合并特发性血小板减少性紫癜(idiopathic thrombocytopeinc purpura,ITP)对胎儿及新生儿血小板的影响。方法选取我院2001年6月~2012年8月妊娠合并特发性血小板减少性紫癜患者56例,分别于孕16周、28周及39周检测母亲血小板数量,56例胎儿于分娩后取胎儿脐静脉血检测血小板数量。结果 6例血小板≤50×109/L且经阴道分娩新生儿有3例(33.3%)发生颅内出血,2例血小板<10×109/L且经阴道分娩新生儿均发生颅内出血。结论胎儿血小板低于50×109/L者应选择剖宫产。     

妊娠合并血小板减少与产后出血原因分析

目的：探讨妊娠合并血小板减少引起产后出血的原因及高危因素。方法回顾性分析该院2006-2011年收治的127例中重度妊娠合并血小板减少患者中发生产后出血的相关因素。结果对于妊娠合并血小板减少患者,孕期有无出血倾向与产后出血的发生相关,P＜0．05,差异有统计学意义;观察组中妊娠合并血小板减少患者具有产后出血高危因素（除血小板减少）与对照组比较。在具备引起产后出血的产科因素中,宫缩乏力仍占首位;产后出血多于产后6h内发生。结论对于血小板减少患者,若孕期有出血倾向、妊娠期高血压、前置胎盘等高危因素,易发生产后出血。分娩时合理应用宫缩剂、严密监测产后6h以内出血情况,可有效避免产后出血。     

慢性特发性血小板减少性紫癜IL2,T细胞亚群研究

应用~3H-TdR掺入法和间接免疫荧光法测定21例慢性ITP外周血IL:活性、T细胞亚群。结果ITP外周血IL_2活性降低,且与T_4/T_8比值呈正相关;ITP外周血T细胞亚群紊乱,表现外周血总T细胞、T辅助细胞百分率降低,T抑制细胞百分率增高。提示ITP存在细胞免疫功能异常。