Pronase independent flow cytometry crossmatching of rituximab treated patients

ABO-incompatible (ABOi) kidney transplantation has become an established strategy to increase the number of available living donors. At our center, the conditioning protocol for ABOi patients is based on anti-A/B antibody removal and depletion of B cells with the anti-CD20 mAb rituximab (Mabthera®). It is known that even low amounts of remaining rituximab in serum of patients results in false positive B cell cross match results, masking detection of potentially harmful donor human leukocyte antigen (HLA) specific antibodies. Treatment of donor cells with high concentrations (>1?mg/mL) of pronase is currently standard procedure for elimination of rituximab (RIT) interference. It is, however, troublesome that recent reports indicate that pronase treatment per se can induce incorrect flow cytometry cross match (FCXM) results. The aim of this study was to evaluate an alternative pronase-free FCXM for crossmatching of patients treated with rituximab.FCXM with an anti-RIT monoclonal antibody (mAb) pre-blocking step were evaluated on normal human sera (NHS) and patient sera supplemented with RIT. NHS supplemented with RIT or patient sera, without donor specific antibodies (DSA), resulted in high B cell median channel shift (>200 IgG) above background. This shift was eliminated by a serum pre-blocking step with 2-fold excess of anti-RIT (clone MB2A4). Blocking with anti-RIT did not influence the T cells crossmatch results. We present data supporting proof-of-concept that blocking with anti-RIT antibody prior to XM can enable reliable detection of anti-HLA class I and II donor specific antibodies without use of pronase treated donor cells.     

A case of autoimmune severe acquired von Willebrand syndrome (type 3-like)

Von Willebrand disease (VWD) is the most common congenital bleeding disorder and is due to quantitative or qualitative defects of von Willebrand factor (VWF). Acquired defects of VWF, termed acquired von Willebrand syndrome (AVWS), are due to a host of different mechanisms. Autoantibody-mediated AVWS may be associated with lymphoproliferative or immunological disorders, such as systemic lupus erythematosus (SLE). A large majority of AVWS cases are type 1 or type 2A-like and patients tend to have a mild to moderate bleeding tendency. We report a case of severe autoimmune AVWS in a woman with SLE who presented with clinical and laboratory features of type 3 VWD (undetectable VWF antigen, ristocetin cofactor activity, and VWF multimers). A mixing study demonstrated an inhibitor to VWF (6 BU/mL). Her bleeds were managed with antifibrinolytics, recombinant activated factor VII, and activated prothrombin complex concentrate. She was initially treated with steroids and intravenous immunoglobulin therapy. However, her bleeding symptoms continued until she was treated with rituximab, and her VWF parameters normalized. She relapsed two years later due to non-compliance with her immunosuppressive medications and expired another two years later secondary to complications of sepsis and uremic pericarditis. This case emphasizes the importance of aggressive initial therapy of SLE to reduce secondary complications, frequent patient monitoring, and continued treatment of the underlying autoimmune disorder in patients with AVWS.     

Management of thrombotic thrombocytopenic purpura

Daily therapeutic plasma exchange (TPE) transformed the historically fatal prognosis of acquired, anti-ADAMTS13 antibody-mediated thrombotic thrombocytopenic purpura (TTP), leading to the current overall survival rates of >80%. However, relapses occur in up to 40% of patients and refractory disease with fatal outcomes still occurs, typically within the first days of management. In this context, the introduction of rituximab has been the second major breakthrough in TTP management. Rituximab is now routinely recommended during the acute phase, typically in patients with a suboptimal response to treatment, and increasingly as frontline therapy, with high response rates in the following weeks. In more severe patients, salvage strategies typically include twice daily TPE, pulses of cyclophosphamide, as well as splenectomy in the more desperate cases. In this life-threatening and debilitating disease, relapses can be efficiently prevented in patients with a severe acquired ADAMTS13 deficiency and otherwise in remission with the use of rituximab. In the coming years, the TTP therapeutic landscape should be enriched by original strategies stemming from clinical experience and new agents that are currently being evaluated in large, international, clinical trials. Promising agents under evaluation include caplacizumab (an inhibitor of the glycoprotein-Ib/IX-Von-Willebrand factor axis), N-acetylcysteine, recombinant ADAMTS13, and anti-plasmocyte compounds.     

“How I treat” autoimmune diseases: State of the art on the management of rare rheumatic diseases and ANCA-associated systemic idiopathic vasculitis

This Special Issue of Autoimmunity Reviews constitutes summaries of presentations at the 20th International Meeting on Immunopathology and Orphan Diseases, held in Torino, Italy, 25–28th January 2017. As such, these presentations represent the state of the art on the pathophysiology of autoimmune diseases as well as the most recent insights into the management of these pathologic conditions. The latter includes both the optimal use of established drugs and approaches as well as novel knowledge on the means and consequences of targeted blocking of molecules or cellular mechanisms.The 2nd Turin Congress on systemic idiopathic vasculitis concluded the works of the International Meeting on Immune Pathology and Orphan Diseases.This Satellite Congress was mainly addressed to the management of antineutrophil cytoplasm antibody (ANCA)-associated vasculitis: advances on induction therapy and maintenance treatment. Guidelines and recommendations were critically discussed, reviewing available evidence and providing experts' insights. New intensive therapeutic approaches had been also reported.     

Successful treatment with rituximab for autoimmune hemolytic anemia concomitant with proliferation of Epstein-Barr virus and monoclonal gammopathy in a post-nonmyeloablative stem cell transplant patient

A 30-year-old Japanese woman who underwent nonmyeloablative stem cell transplantation from her HLA-matched sister developed autoimmune hemolytic anemia (AIHA). There was proliferation of EBV-DNA in her peripheral blood and monoclonal gammopathy, both predictive factors of post-transplant lymphoproliferative disorder (PTLD). As conventional immunosuppressive therapy for AIHA could lead to overt PTLD, we decided to give her rituximab 375 mg/m² once weekly for a total of four doses. After this therapy, both her AIHA and monoclonal gammopathy were resolved and EBV-DNA became undetectable. Rituximab therapy deserves consideration for treatment of post-allogeneic stem cell transplant patients with AIHA, especially for patients who cannot be given immunosuppressive therapy.     

A varicella outbreak in B-cell lymphoma patients receiving rituximab-containing chemotherapy

Varicella, characterized by a vesicular rash, occurs primarily in young children. Although older individuals can also be affected or vaccinated, outbreaks among adults are rare. We investigated a small outbreak of varicella in B-cell lymphoma patients for elucidation of risk factor of the disease. We experienced four cases of varicella after an index herpes zoster case. All varicella cases were confirmed varicella zoster virus (VZV) infection by PCR. All varicella cases occurred in diffuse large B-cell lymphoma patients receiving rituximab-containing chemotherapy. On the other hand, only three of the 18 non-varicella patients in the same room were receiving rituximab-containing chemotherapy (P = 0.005). All varicella patients had detectable serum anti-varicella zoster virus IgG antibodies before chemotherapy. Even in the presence of neutralizing antibodies to the virus, lymphoma patients treated with rituximab-containing chemotherapy can possibly become re-infected with varicella. These findings suggest that zoster patients should be strictly isolated in hematology and oncology ward, and prophylactic acyclovir should be considered for such patients when exposed to zoster/varicella.     

美罗华联合CHOP方案治疗B细胞性非霍奇金淋巴瘤效果观察

目的：探讨美罗华联合CHOP方案治疗B细胞性非霍奇金淋巴瘤的临床效果及不良反应。方法选择B细胞性非霍奇金淋巴瘤60例随机分成观察组和对照组各30例。观察组采用美罗华联合CHOP方案治疗,对照组仅采用CHOP方案治疗,比较两组临床疗效及不良反应情况。结果观察组患者临床疗效明显优于对照组（ P＜0.05）;不良反应除发热例数多于对照组外（ P＜0.05）,其余两组比较差异无统计学意义（P＞0.05）。结论对B细胞性非霍奇金淋巴瘤患者采用美罗华联合CHOP方案治疗,能够有效提高患者的临床疗效,值得临床推广。     

低剂量利妥昔单抗治疗15例温抗体型自身免疫性溶血性贫血的疗效观察

目的观察低剂量利妥昔单抗联合地塞米松治疗15例温抗体型自身免疫性溶血性贫血的疗效及安全性。方法对2007年1月-2012年10月我院收治的15例温抗体型自身免疫性溶血性贫血（WAIHA）患者（其中1例为Evans综合征）采用以下方案进行治疗：在第1、8、15、22天给予利妥昔单抗100mg／次;给予利妥昔单抗前5d开始给予地塞米松20mg／d,共5次。结果总有效率为86．7％（13／15）,中位起效时间为2个月（四分位数间距1．5个月）,中位随访时间为12个月（四分位数间距4个月）。复发患者再次强化治疗仍有效。部分缓解患者抗体效价降低。1例Evans综合征患者未出现出血倾向,血小板持续维持在（90～130）×10^9／L。所有患者对该治疗方案耐受性良好,不良事件发生率低。结论低剂量利妥昔单抗联合地塞米松治疗WAIHA安全、高效。     

UC-MSC联合利妥昔单抗及甲强龙对系统性红斑狼疮免疫炎性易栓状态的影响作用

目的初步探讨脐带间充质干细胞（umbilical cord mesenchymal stem cells,UC-MSC）联合利妥昔单抗（rituximab,美罗华）与甲强龙对系统性红斑狼疮（systemic lupus erythematosus,SLE）患者免疫炎性易栓状态的干预作用。方法8例SLE患者经肾活检确诊为狼疮性肾炎。予SLE活动指数（SLEDAI积分）评价病情活动程度;流式细胞术（FCM）监测B细胞清除、T细胞亚群及炎症介质表达水平;酶联免疫吸附法（ELISA）检测抗心磷脂抗体（ACA）、狼疮抗凝物（LA）水平;以磁珠法检测血凝常规、血浆D二聚体（D-D）、抗凝血酶（AT）等。结果随访第1个月临床症状明显改善,CD19和CD20降至＂0＂;至第3个月全组SLEDAI评分〈4分,Th1（IFN-γ）、Th2（IL-4）及CD11b、CD25水平均接近正常;随访至1年上述指标维持在正常值内。结论利妥昔单抗联合UC-MSC所具有的靶向作用,能有效清除外周血致病性B细胞,恢复Th1/Th2免疫平衡状态,减少炎症因子释放,促进机体免疫重建,恢复凝血-抗凝系统平衡,从而改善机体免疫炎性易栓状态。     

利妥昔单抗治疗难治性激素耐药型肾病综合征的疗效和安全性

目的探讨利妥昔单抗(RTX)治疗儿童难治性激素耐药型肾病综合征(SRNS)的疗效和安全性。方法回顾性分析2013年9月至2018年3月东部战区总医院儿科收治并接受RTX治疗的10例难治性SRNS患儿的临床资料。结果10例患儿发病年龄(4.47±2.75)岁,男女各5例;5例(50%)肾活检为局灶节段性肾小球肾炎,3例(30%)为微小病变肾病,1例(10%)为IgM肾病,1例(10%)为系膜增生性肾小球肾炎。10例患儿于(6.74±2.62)岁时行RTX治疗(1剂或4剂,每次375 mg/m²,最大500 mg);治疗1次、3次、8次分别为8例(80%)、1例(10%)、1例(10%)。随访时间11.93(5.17,25.66)个月;随访3个月、6个月以及最后一次随访的缓解率分别为30%(3例)、40%(4例)、40%(4例)。10例患儿RTX治疗前后24 h尿蛋白及白蛋白水平有所改善,但差异均无统计学意义(均P>0.05);治疗前后体液免疫及肾功能无明显变化(均P>0.05)。在治疗及随访过程中,3例(30%)出现输液反应,2例(10%)出现严重肺部感染,1例(10%)严重肺部感染死亡。结论RTX对部分难治性SRNS患儿治疗有效,治疗后需长期随访,避免感染。