Splenic pathology in immune thrombocytopenia.

Splenic pathology was analysed in 73 patients with immune thrombocytopenic purpura who underwent splenectomy for bleeding that had been resistant to adrenocorticosteroids. The mean splenic weight was 100 g. The only notable macroscopic feature was the prominence of Malpighian corpuscles in 15 cases. Microscopic examination showed formation of germinal centres in the lymphoid tissue of the white pulp in 40 cases, prominence of the histiocytes in the red pulp in 18 cases, and infiltration with neutrophils in the same area in 49 cases. Myeloid metaplasia throughout the splenic tissue was minimal in 58 cases, moderate in 15, and extreme in two. No distinguishing features were found in the spleen from patients who had not received previous immunosuppressive treatment (n = 3), those treated with prednisone (1 mg/kg/day) for a median of 14 days (n = 62), or those who had received the same dose of prednisone and additional azathioprine or cyclophosphamide (2 mg/kg/day) for a median of four weeks (n = 8). No correlation could be shown between histological features and the age of the patient or titre of antiplatelet antibodies. Similarly, no distinguishing features were found in patients with associated systemic lupus erythematosus (n = 8), hyperthyroidism (n = 6), immune haemolysis (n = 3), or recent viral illness (n = 3).     

射频消融治疗顽固性免疫性血小板减少症

目的探讨脾脏射频消融术治疗顽固性免疫性血小板减少症（ITP）的安全性和有效性。方法回顾分析我院开展的国际首例脾脏射频消融治疗ITP的疗效。结果 1例43岁女性食管癌患者,经反复外周血计数、血涂片和骨髓穿刺等检查证实合并原发性重症ITP,其血小板计数小于（5~10）×109/L,经规范抗幽门螺旋杆菌治疗、静滴人免疫球蛋白、甲基强的松龙、长春新碱和输注血小板等治疗无效。患者接受腹腔镜下脾脏射频消融术治疗,术后第22天血小板计数恢复正常,无围手术期并发症;随访超过8个月,患者呈完全应答。结论脾脏射频消融术治疗顽固性ITP安全、有效,值得扩大临床试验进一步验证其疗效。     

Treatment of septic thrombocytopenia with immune globulin

Thrombocytopenia frequently complicates systemic infection and results from multiple possible mechanisms. We and others have demonstrated that platelet-associated IgG (PAIgG) levels are elevated in the majority of patients with septic thrombocytopenia. Corticosteroids may be undesirable as a treatment for thrombocytopenia for patients with severe infection because of their potential for suppressing the immune response. We hypothesized that septic thrombocytopenia is, in most cases, an immune disorder analogous to idiopathic thrombocytopenic purpura (ITP) which might respond to intravenous gamma-globulin as a treatment for increasing the platelet count in this disorder. Intravenous immune globulin (IVIG), 400 mg/kg daily for 3 days, was administered in a randomized double-blind placebo-controlled trial. Twenty-nine patients who developed thrombocytopenia during a documented, septic episode were studied. Patients with disseminated intravascular coagulation (DIC), hypersplenism, or drugs known to cause thrombocytopenia were excluded. Elevated PAIgG levels were documented in 52% of evaluable patients. Mean platelet counts in the IVIG group rose from 43K at study entry to 178K (411% rise) by Day 9. In the placebo group platelets rose from 51K to 125K (261% rise;P = 0.02). Seventy-seven percent of the IVIG group had a minimum peak rise of 35K, vs 56% of the placebo group. Three patients in the placebo group had a serious bleeding episode, vs one in the IVIG group. The use of IVIG to treat septic thrombocytopenia not associated with DIC leads to a more rapid, more sustained, and greater increase in platelet count than placebo. Its use is recommended in the septic patient who is bleeding or is likely to need invasive or surgical procedures.     

Avatrombopag for the treatment of immune thrombocytopenia

Introduction: Thrombopoietin-receptor agonists (TPO-RAs) are the only American Society of Hematology (ASH) guideline-advocated, second-line treatment for immune thrombocytopenia (ITP) that have been validated by randomized, controlled trials with a placebo comparator. Avatrombopag is a new candidate in this class that has been investigated as a treatment option for the treatment of ITP.

Areas covered: In this Drug Profile, we provide a review of the clinical data of avatrombopag, which was approved in May 2018 by the United States Food and Drug Administration (FDA) for the treatment of thrombocytopenia in patients with chronic liver disease undergoing an invasive procedure, and an opinion of its potential place in the current evidence-based ITP treatment landscape.

Expert commentary: Avatrombopag induces doubling of platelet counts, increasing them to above 50 X 10⁹/L, and prevents the need for platelet transfusions while minimizing the need for rescue medications. Treatment-emergent adverse events (TEAEs) are comparable to placebo. Oral delivery, a 5-day dosing schedule and good tolerability (<1% discontinuation rate) with no clinically significant hepatoxicity make it a promising entrant as a potential second-line treatment for ITP. Further, data from a phase 3 study in patients with ITP supports its utility in the treatment of patients with ITP.     

Alpha-methyldopa-induced immune thrombocytopenia. Report of case.

The clinical and laboratory features of a case of alphamethyldopa-induced thrombocytopenia are described. This is the second reported case in which the presence of alpha-methyldopa-induced platelet antibodies have been demonstrated.     

Pathogenesis of immune thrombocytopenia in common variable immunodeficiency

Immune Thrombocitopenic Purpura (ITP) is an autoimmune disease characterized by antibody-mediated platelet destruction and variable reduced platelet production. Besides antibody-mediated platelet destruction, new pathogenic mechanisms have been reported to be involved in reducing platelet count. Among these, desialylation is one of the most recent and innovative mechanisms that has been found to be implied, at least in part, in non-antibody mediated platelet clearance.Common Variable Immunodeficiency (CVID) is the most common Primary Immunodeficiency seen in clinical practice. About 25–30% of CVID patients are affected by autoimmune manifestation, among which ITP is the most common. Little is know about pathophysiological mechanisms that lead to ITP in CVID.Given the poor antibody production typical of CVID patients, we aimed at verifying whether platelet desialylation could be responsible for CVID associated thrombocytopenia.According to our results, we may suggest that in CVID patients, ITP is due to a decreased bone marrow platelets production, rather than an increased peripheral platelet destruction, which is more common in patients with primary ITP. An increased platelet desialylation does not appear to be implicated in the thrombocytopenia secondary to CVID, while it is implicated in the pathogenesis of primary ITP. Nevertheless an intriguing aspect has emerged from this study: regardless the presence of thrombocytopenia, the majority of CVID patients present a double platelet population as far as desialylation concerns, whilst no one of the healthy donors and of the patients with primary ITP shows a similar characteristic.     

Vancomycin-induced neutropenia associated with anti-granulocyte antibodies

Neutropenia is a rare complication associated with vancomycin, and the cause of this adverse reaction is not well understood. We report a case of vancomycin-induced neutropenia in which we were able to demonstrate anti-granulocyte antibodies. We also report the results of a hone marrow examination along with a brief review of the literature.     

Target platelet antigen in homosexual men with immune thrombocytopenia

A syndrome of isolated immune thrombocytopenic purpura (ITP) has recently been described in homosexual men. We have identified an antiplatelet antibody in the serum of 29 of 30 homosexual men with isolated ITP. The antibody binds to a platelet membrane antigen of 25,000 daltons, and binding is effected by the F(ab)2 portion of the immunoglobulin. Similar antibody activity was not detected in serum from 30 nonhomosexual patients with either ITP or nonimmune thrombocytopenia. The 25,000-dalton antigen was not found on other hematopoietic cells, and it was distinct from the core protein of the AIDS-associated retrovirus. In contrast, serum antibody reacted with a 25,000-dalton antigen associated with cultured herpes simplex virus Types I and II. In these experiments the antigen appeared to be derived from green-monkey kidney cells in which the herpes simplex viruses were grown. Identical antigenic activity was also demonstrated in uninfected human skin fibroblasts. We conclude that ITP in homosexual men is accompanied by a serum antibody directed against a platelet antigen of 25,000 daltons. The nature of the antigen and the relation of the serum antibody to ITP require further study.