Autoimmune-prone (NZW × BXSB)F1 (W/BF1) mice escape severe thrombocytopenia after treatment with deoxyspergualin, an immunosuppressant

Summary. Male (NZW × BXSB)F₁ mice spontaneously develop a disease which closely resembles human systemic autoimmune disease, involving idiopathic thrombocytopenic purpura and glomerulonephritis. We investigated whether autoimmune thrombocytopenia in the mice responded to deoxyspergualin, as immunosuppressant. Deoxyspergualin completely prevented the development of thrombocytopenia and suppressed the increase in circulating autoantibodies against platelets. This agent also ameliorated lupus nephritis. These findings suggest that deoxyspergualin may be effective in the prevention of idiopathic thrombocytopenic purpura.     

The Oklahoma Thrombotic Thrombocytopenic Purpura-Hemolytic Uremic Syndrome Registry: the Swiss connection

Objectives: Thrombotic thrombocytopenic purpura (TTP) was initially described as an uncommon and usually fatal disorder. With effective treatment it is more frequently diagnosed, the clinical presentations are more diverse, and long‐term sequelae are becoming recognized. Methods: Patient data are from The Oklahoma TTP‐hemolytic uremic syndrome (HUS) Registry, an inception cohort of 348 consecutive patients with their first episode of clinically diagnosed TTP or HUS, 1989–2006. The Registry enrolls all patients in a defined region who are diagnosed with TTP or HUS and for whom plasma exchange treatment is requested. ADAMTS13 activity has been analyzed on 235 (93%) of 254 patients since 1995 at the University of Berne, Switzerland. Patients are described by clinical categories, related to their associated conditions and clinically apparent etiologies, and by the presence of severe ADAMTS13 deficiency. Results and conclusions: The clinical spectrum of syndromes described as TTP is variable with multiple etiologies. Advances in clinical and laboratory investigation have provided better understanding of the pathogenesis of these syndromes, their clinical evaluation and management, and their long‐term outcomes. In addition to new information about TTP, these studies provide a model for translational research to define the complete community spectrum of uncommon disorders.     

Citrate anticoagulation during plasma exchange in a patient with thrombotic thrombocytopenic purpura: short heparin-free hemodialysis helps to attenuate citrate load

The treatment of thrombotic thrombocytopenic purpura requires plasma exchange using fresh frozen plasma as a replacement solution once or even twice daily. If citrate anticoagulation is needed, the citrate load (both from fresh frozen plasma and citrate as an anticoagulant) can be significant, causing metabolic complications. The aim of our report is to present our experience with citrate anticoagulation in a patient with thrombotic thrombocytopenic purpura treated with daily membrane plasma exchange. Twenty-six plasma exchange procedures were performed during 20 days of treatment in a 46-year-old female. The blood flow was 98 +/- 8 mL/min; 4% trisodium citrate was infused into the arterial line (134 +/- 11 mL/h) and 1 M CaCl2 into the venous line (11.4 +/- 1.8 mL/h). Fresh frozen plasma (first 7 procedures) or cryo-poor plasma (19 procedures) were used as a replacement solution, 3176 +/- 536 mL per procedure. A total of 88,930 mL of plasma was exchanged. No serious side-effects occurred. iCa before plasma exchange was significantly higher than afterwards (1.23 +/- 0.12 vs. 1.12 +/- 0.12, P = 0.0047). Significant alkalosis occurred after three plasma exchanges (pH 7.64, bicarbonate 36.2 mmol/L), and was corrected by 3-h heparin-free hemodialysis with dialysate as follows: K 4.0 mmol/L, calcium 1.5 mmol/L, and bicarbonate set to 24 mmol/L. After dialysis, pH was 7.45 and bicarbonate 29.4 mmol/L. Another (2-h) heparin-free hemodialysis procedure was repeated after six plasma exchanges. Citrate anticoagulation can be safely performed in patients treated with plasma exchange once or twice daily. Periodically performed short heparin-free hemodialysis can correct metabolic alkalosis and attenuate the citrate load.     

静脉输注丙种球蛋白治疗特发性血小板减少性紫癜

目的:分析静脉输注丙种球蛋白治疗特发性血小板减少性紫癜(ITP)的疗效。方法:静脉输注丙种球蛋白(IVIG)0.4g·kg-1·d-1,连用5d。结果:25例患者经治疗后,显效11例(44%),其中基本治愈5例(20%);良好效果6例(24%);进步4例(16%);无效4例(16%),总有效率为84%。结论:治疗重症、难治性ITP患者,IVIG是一种安全、有效、无不良反应的治疗方法。特别对≤14岁的患儿和初治病例疗效更佳。并可反复使用,复发患者用糖皮质激素治疗仍有效。     

Thrombotic thrombocytopenic purpura in patients with retroviral infection is highly responsive to plasma infusion therapy

We prospectively studied presentation biological differences and the response to therapy in patients with thrombotic thrombocytopenic purpura (TTP) associated with, or unrelated to human immunodeficiency virus (HIV) infection. TTP patients underwent standard evaluations and were treated with prednisone 1 mg/kg in addition to infusions of fresh frozen plasma (FFP; 30 ml/kg/d) until normalization of the platelet count. Unresponsive patients were referred for plasma exchange. Compared with HIV- TTP patients (n=23), in HIV+ subjects (n=21) microangiopathy was dominant among Black females, who had lower presentation Hb (median 5.8 g/dl; P=0.03), platelet count (13 x 10(9)/l; P=0.05) and a CD4 count of 0.096 x 10(9)/l. HIV+ individuals responded to FFP faster than HIV- patients and none of them required apheresis. Ten HIV- TTP patients required apheresis (P=0.03) and four died. Responses in the HIV+ and HIV- groups occurred after treatment with a median of 33 and 55 units (one unit=320 ml) of FFP (P=0.004) respectively. Response to this protocol was seen in 84% (95% response in HIV+ patients). Regression analysis showed that survival was associated with younger age (P=0.001), rapid platelet (P=0.001) and Hb (P=0.0009) recovery, and fewer FFP units to normal lactate dehydrogenase levels (P=0.006). We conclude that in HIV+ individuals, microangiopathy is highly responsive to plasma infusions. This observation is important particularly when apheresis is not available.     

The IgG subclasses of platelet-associated autoantibodies directed against platelet glycoproteins IIb/IIIa in patients with idiopathic thrombocytopenic purpura

The majority of patients with idiopathic thrombocytopenic purpura (ITP) have antiplatelet autoantibodies that are most frequently directed against platelet glycoproteins IIb/IIIa or Ib/IX/V. However, there is some debate whether the immune response is oligoclonal or polyclonal in nature. We investigated the subclass distribution of anti-IIb/IIIa IgG autoantibodies in 59 prospectively studied patients with ITP. We also tested patients with a variety of thrombocytopenic disorders (n=31) and healthy controls (n=30). Platelet lysates were tested for IgG anti-IIb/IIIa autoantibodies, and the specific IgG subclass distribution was measured using antigen capture assays. All testing was done blinded to diagnosis and other assay results. After unblinding, we found that 43 of the 59 ITP patients had anti-IIb/IIIa autoantibodies (sensitivity=73%). Anti-IIb/IIIa autoantibodies were also detected in five of the 31 non-ITP patients, but in none of the 30 healthy controls (specificity=91%). The IgG subclass assay was positive in 39 of the 43 ITP patients with anti-IIb/IIIa antibodies (sensitivity=92%) and in 12 samples that had no detectable anti-IIb/IIIa antibodies including two ITP patients (specificity=83%). The most common subclass in the ITP patient samples was IgG1 (77%), either alone (n=14) or with other IgG subclass antibodies (n=19). However, there were also patients with only IgG2 (n=2), IgG3 (n=3) or IgG4 (n=3) antibodies. Our results are consistent with the hypothesis that ITP is a heterogeneous disorder and that some patients have evidence of oligoclonality, whereas other patients have polyclonal autoantibodies.     

Successful treatment of idiopathic thrombocytopenic purpura by Chinese herbal medicine EK-49 and ascorbic acid in an elderly patient developing chronic subdural hematoma

Treatment of idiopathic thrombocytopenic purpura can present difficult therapeutic choices. An 88-year-old woman was admitted for treatment of a right subdural hematoma. She had a history of chronic thrombocytopenia, with follow-up evaluations by a local physician. Platelet count on admission was 5 × 10³/µL, with a high serum concentration of platelet-associated immunoglobulin G. Bone marrow examination showed a marked increase in megakaryocytes. The patient was diagnosed with idiopathic thrombocytopenic purpura accompanied by chronic subdural hematoma. An increase in platelet count and gradual resolution of the subdural hematoma were obtained with prednisolone and azathioprine administration, but platelet count decreased when steroid tapering was attempted. Ultimately we administered the Chinese herbal medicine EK-49 and ascorbic acid, with a gradual increase in platelet count and no adverse effects. Some elderly patients with chronic subdural hematoma can be treated non-invasively. Further, a combination of EK-49 and ascorbic acid may be an effective treatment for refractory idiopathic thrombocytopenic purpura.     

High Th1/Th2 ratio in patients with chronic idiopathic thrombocytopenic purpura

Chronic immune thrombocytopenic purpura (ITP) is an autoimmune disorder characterized by increased platelet clearance because of antiplatelet antibodies. It was recently reported that the balance of T helper 1 (Th1) and T helper 2 (Th2) subsets has been implicated in the regulation of many immune responses. In this study, the intracellular interleukin-4 and interferon-gamma production in CD4+ T-lymphocytes activated by phorbol 12-myristate 13-acetate and ionomycin was assessed via flow cytometry in order to determine the clinical significance of the Th1/Th2 ratio in 42 patients with ITP. The study cohort included 28 untreated patients, seven postprednisolone therapy patients and seven postsplenectomy patients. The mean level of the Th1/Th2 ratio in the untreated group was 36.9 (95% CI 25.8-47.9), and significantly higher than in the control group (mean 12.8, 95% CI 9.5-16.1). The mean levels of the Th1/Th2 ratio in the postprednisolone therapy and postsplenectomy groups were 20.5 (95% CI 8.4-32.6) and 16.4 (95% CI 3.1-29.7), respectively, but were no significant differences as compared with control subjects. When untreated patients were divided into two subgroups by Th1/Th2 ratio, the mean level of platelet associated IgG in the high Th1/Th2 subgroup (higher than upper limit of control group) tended to be higher than in the normal Th1/Th2 subgroup. In conclusion, the high Th1/Th2 ratio was closely related to the etiology and disease status of chronic ITP.     

Quantification of red blood cell fragmentation by the automated hematology analyzer XE‐2100 in patients with living donor liver transplantation

The fragmented red cell (FRC) is a useful index for diagnosing and determining the severity of thrombotic thrombocytopenic purpura (TTP), thrombotic microangiopathy (TMA) and other similar conditions, as it is found in peripheral blood in patients with these diseases. The FRC expression rate has conventionally been determined by manual methods using smear samples. However, it is difficult to attain accurate quantification by such methods as they are time consuming and prone to a great margin of error. With cases of living donor liver transplantation, the current study examined the possibility of using a multi‐parameter automated hematology analyzer, the XE‐2100 (Sysmex Corporation) for FRC quantification. While there was a notable correlation between the manual and automated measurements, the manual measurement resulted in higher values. This suggested remarkable variations in judgment by individuals. The FRC values had a significant correlation with the reticulocyte count, red blood cell distribution width (RDW), fibrin/fibrinogen degradation products (P‐FDP) and lactate dehydrogenase (LDH) among the test parameters, and this finding was consistent with the clinical progression in patients. The automated method can offer precise measurements in a short time without inter‐observer differences, meeting the requirement for standardization. The determination of FRC count (%) by the XE‐2100 that enables early diagnoses and monitoring of TTP or TMA will be useful in the clinical field.     

The role of human leukocyte antigen DRB1-DQB1 haplotypes in the susceptibility to acquired idiopathic thrombotic thrombocytopenic purpura

The acquired form of idiopathic thrombotic thrombocytopenic purpura (TTP) is an autoimmune disease, in which the underlying ADAMTS13-deficiency is caused by inhibitory autoantibodies against the protease. Human leukocyte antigens (HLA), responsible for antigen presentation, play an important role in the development of antibodies. The loci coding HLA DR and DQ molecules are inherited in linkage as haplotypes. The c.1858C>T polymorphism of the PTPN22 gene, which codes a protein tyrosine phosphatase important in lymphocyte activation, predisposes to a number of autoimmune diseases. We determined the HLA-DRB1-DQB1 haplotypes and the PTPN22 c.1858C>T genotypes in 75 patients with acquired idiopathic TTP and in healthy controls, in order to assess the role of these genetic factors and their interactions in the susceptibility to TTP. We found that the carrier frequencies of the DRB1¹11-DQB1¹03 and DRB1¹15-DQB1¹06 haplotypes were higher, while those of the DRB1¹07-DQB1¹02 and DRB1¹13-DQB1¹06 haplotypes were lower in TTP patients. There was no difference in the overall frequency of the PTPN22 c.1858T allele between TTP patients and controls. In conclusion, we identified four HLA-DRB1-DQB1 haplotypes associated with an increased (DRB1¹11-DQB1¹03 and DRB1¹15-DQB1¹06) or a decreased (DRB1¹07-DQB1¹02 and DRB1¹13-DQB1¹06) susceptibility to acquired idiopathic TTP.