Mechanisms and clinical implications of thrombosis in paroxysmal nocturnal hemoglobinuria

Summary. Paroxysmal nocturnal hemoglobinuria (PNH) is a rare acquired disease characterized by a clone of blood cells lacking glycosyl phosphatidylinositol (GPI)‐anchored proteins at the cell membrane. Deficiency of the GPI‐anchored complement inhibitors CD55 and CD59 on erythrocytes leads to intravascular hemolysis upon complement activation. Apart from hemolysis, another prominent feature is a highly increased risk of thrombosis. Thrombosis in PNH results in high morbidity and mortality. Often, thrombosis occurs at unusual locations, with the Budd–Chiari syndrome being the most frequent manifestation. Primary prophylaxis with vitamin K antagonists reduces the risk but does not completely prevent thrombosis. Eculizumab, a mAb against complement factor C5, effectively reduces intravascular hemolysis and also thrombotic risk. Therefore, eculizumab treatment has dramatically improved the prognosis of PNH. The mechanism of thrombosis in PNH is still unknown, but the highly beneficial effect of eculizumab on thrombotic risk suggests a major role for complement activation. Additionally, a deficiency of GPI‐anchored proteins involved in hemostasis may be implicated.     

阵发性睡眠性血红蛋白尿症患者血栓前状态的研究

目的：探讨阵发性睡眠性血红蛋白尿症（ＰＮＨ）患者易发生血栓形成的机制。方法：对２１例ＰＮＨ患者测定了１３项能反映血栓前状态的分子标志物或指标。结果：与正常对照比较，患者血浆纤维蛋白肽Ａ（ＦＰＡ）水平明显增高，抗凝血酶－Ⅲ（ＡＴ－Ⅲ）和蛋白Ｃ（ＰＣ）降低，血浆组织型纤溶酶原激活物（ｔ－ＰＡ）活性明显降低，ｔ－ＰＡ抑制物（ＰＡＩ）活性增高。血红蛋白尿急性发作期上述凝血与纤溶指标的变化较静止期更显著，合并血栓形成者变化的幅度最大。患者血小板相关指标无明显变化，血浆内皮素－１（ＥＴ－１）和ｖＷＦ∶Ａｇ水平正常。结论：ＰＮＨ患者存在血栓前状态，其发生可能主要与凝血机制亢进和纤溶机能减弱有关。     

Clinical observation of low‐dose combination chemotherapy in refractory/recurrent paroxysmal nocturnal hemoglobinuria patients: A single‐center retrospective analysis

BackgroundWe performed a retrospective analysis to investigate the clinical characteristics and therapeutic strategies of 20 refractory/recurrent PNH patients, including the clinical efficacy of chemotherapy treatment, safety, and survival.MethodsThe clinical data of 20 classic PNH patients who were refractory/recurrent or had glucocorticoid dependence in our hospital were analyzed, including clinical manifestations, laboratory examinations, treatment efficacy, and survival.ResultsSeventeen patients had a marked improvement in anemia after chemotherapy, 14 patients acquired blood transfusion independence, and the Hb of 3 patients increased to normal levels. Although 6 patients still needed blood transfusion, the transfusion interval was significantly prolonged. The percentages of LDH, TBIL, and RET, which are indicators of hemolysis, were significantly lower than those before chemotherapy. The dosage of adrenal glucocorticoids was reduced by more than half compared with that before chemotherapy.ConclusionsChemotherapy can reduce PNH clones, promote normal hematopoiesis, and control hemolytic attack. It is a promising and widely used therapeutic method.     

阵发性睡眠性血红蛋白尿症血细胞免疫表型的研究

目的：探讨血细胞膜表面糖基磷脂酰肌醇（ＧＰＩ）锚蛋白分子表达异常在诊断阵发性睡眠性血红蛋白尿症（ＰＮＨ）时的意义。方法：应用一组单克隆抗体，采用免疫荧光法检测２２例ＰＮＨ患者粒细胞、红细胞、淋巴细胞的免疫表型。结果：发现ＰＮＨ患者粒细胞和红细胞膜表面与ＧＰＩ锚接蛋白有关的抗原ＣＤ５５和ＣＤ５９表达异常，而且较常规的溶血检查敏感。结论：检测血细胞膜表面ＧＰＩ锚蛋白分子表达可为确定或排除ＰＮＨ的诊断提供敏感、特异的证据。     

Primary biliary cirrhosis–autoimmune hepatitis overlap syndrome in a patient with paroxysmal nocturnal hemoglobinuria: a case report

Primary biliary cirrhosis (PBC)–autoimmune hepatitis (AIH) overlap syndrome is frequently associated with extrahepatic autoimmune disorders. Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired disease that is characterized by complement-mediated hemolysis due to erythrocyte membrane defects. However, autoimmune liver disease was not previously reported to be associated with PNH. A 37-year-old female patient was referred to our hospital with elevated liver enzymes and hematuria. On the basis of the symptoms and results of laboratory tests, radiographic studies, and pathologic results, she was diagnosed with PBC–AIH overlap syndrome and PNH. She was treated with a combination of ursodeoxycholic acid and prednisolone. The patient was symptom-free, with laboratory findings within near-normal range. The patient had recovered well at the 24-month follow-up evaluation. While we acknowledge that this was a single case, these findings expand our knowledge of immunological diseases that are associated with PNH and suggest an immune-mediated pathogenic pathway between PNH and PBC–AIH overlap syndrome. The combination of ursodeoxycholic acid and prednisolone can achieve therapeutic success. Routine follow-up of these patients is necessary to document disease progression.     

用流式细胞仪检测CD_(59)表型对诊断阵发性睡眠性血红蛋白尿症的意义

目的：探讨根据免疫表型检出糖化肌醇磷脂（ＧＰＩ）缺陷细胞在阵发性睡眠性血红蛋白尿症（ＰＮＨ）诊断中的意义。方法：用ＦＩＴＣ标记的ＣＤ５９单抗，以流式细胞仪分析２９例ＰＮＨ患者外周血及骨髓中ＣＤ５９－细胞的百分率。结果：正常人外周血红细胞、中性粒细胞（ＰＭＮ）及骨髓单个核细胞（ＭＮＣ）中的ＣＤ５９－细胞均＜５％，而２８例ＰＮＨ红细胞的ＣＤ５９－细胞均＞１０％（１２．８％～９８．０％），２９例ＰＭＮ均＞１０％（１２．０％～９０．１％），１５例骨髓ＭＮＣ均＞１０％（１７．９％～７３．５％）。１０例表现不典型或Ｈａｍ试验阴性者经本法确诊为ＰＮＨ，７例疑为本病者经本法否定。结论：用流式细胞仪检测ＣＤ５９表型是目前诊断ＰＮＨ的较直接而又特异、敏感的方法。     

中国人阵发性睡眠性血红蛋白尿症的PIG—A基因突变的观察

目的：观察中国人阵发性睡眠性血红蛋白尿症（ＰＮＨ）的ＰＩＧ－Ａ基因突变，以与其他国家的突变类型比较。方法：应用逆转录－多聚酶链反应、异源双链分析／单链构象分析互补筛选异常片段，克隆，测序，针对ＰＩＧ－ＡｃＤＮＡ全长设计７个区域进行分析。结果：４例ＰＮＨ患者均有ＰＩＧ－Ａ基因突变，皆在第２外显子，共确定了５个突变位点，包括４个单碱基突变（１个同义突变，３个错义突变）和１个移码突变（为１个碱基丢失）。５个突变位点各不相同，散布于基因的不同区域，显示突变位点有随意性，无突变热点。结论：中国ＰＮＨ患者的ＰＩＧ－Ａ基因突变均为小突变，无两个以上碱基置换或丢失。此发现与日本人相近，而与欧美、泰国人有一定差异，提示ＰＮＨ在不同地区可能有不同的致突变原。     

原发性骨髓纤维化伴阵发性睡眠性血红蛋白尿1例并文献复习

分析原发性骨髓纤维化（primary myelofibrosis, PMF）伴阵发性睡眠性血红蛋白尿(paroxysmal nocturnal hemoglobinuria, PNH）患者的临床特征,应用细胞化学染色及银染色等行骨髓象及骨髓病理检查,应用流式细胞术（FCM）检测红细胞及粒细胞表面的CD55、CD59,对粒、单核细胞进行荧光标记的嗜水气单胞菌素前体的变异体(FLAER)检测,为进一步确诊,应用高通量测序技术（又称二代测序）进行基因检测。该患者临床上表现为重度脾大、贫血,查骨髓象考虑PMF之可能,骨髓病理示骨髓纤维化（myelofibrosis, MF）3级。基因检测示：BCR/ABL融合基因阴性,JAK2 V617F基因突变阳性。故诊断为：PMF。给予达那唑、十一酸睾酮、促红细胞生成素（erythropoietin, EPO）、沙利度胺、血制品支持等治疗过程中出现血制品输注无效,伴茶色尿,完善相关检查：血常规示网织红细胞偏高,直接胆红素、间接胆红素偏高,抗人球蛋白试验（Coombs test）2次均为阴性,FCM示CD55、CD59降低,FLAER示粒、单表达缺陷,PIG A基因突变阳性,故最终诊断为：PMF合并PNH。     

CD59检测在阵发性睡眠性血红蛋白尿症诊断中的意义

目的　探讨CD5 9检测对阵发性睡眠性血红蛋白尿症 (paroxysmalnocturnalhemoglobinuria ,PNH)及再生障碍性贫血 (AA) PNH综合征的临床诊断意义。方法　用FITC标记的CD5 9单抗 ,以流式细胞仪检测 13例PNH、37例AA和 2 0例正常人外周血红细胞和粒细胞膜表面CD5 9的表达情况。结果　正常人红细胞和粒细胞CD5 9表达阳性率均 >98% ;13例PNH患者红细胞及粒细胞CD5 9表达阳性率均 <90 % ;37例再障患者中 2 4例表达正常 ,13例红细胞或粒细胞CD5 9表达阳性率均有不同程度的减低。结论　CD5 9检测是诊断PNH较直接而又特异、敏感的方法 ,特别是对表现不典型的PNH及AA PNH综合征的诊断具有重要意义     

Posthepatectomy jaundice induced by paroxysmal nocturnal hemoglobinuria: A case report

BACKGROUNDJaundice is a major manifestation of posthepatectomy liver failure, a feared complication after hepatic resection. Herein, we report a case of posthepatectomy jaundice that was not caused by liver failure but by paroxysmal nocturnal hemoglobinuria (PNH)-induced hemolysis.CASE SUMMARYA 56-year-old woman underwent right hepatectomy and biliary tract exploration surgery due to hepatic duct stones. Prior to surgery, the patient was mildly anemic. The direct antiglobulin test was negative. A bone marrow biopsy showed mild histiocyte hyperplasia. After surgery, the patient suffered a progressive increase in serum bilirubin. Meanwhile, the patient developed hemolytic symptoms after blood transfusion. She was ultimately diagnosed with PNH. PNH is a rare bone marrow failure disorder that manifests as complement-dependent intravascular hemolysis with varying severity. After steroid treatment, the patient’s jaundice gradually decreased, and the patient was discharged on the 35^th postoperative day.CONCLUSIONPNH-induced hemolysis is a rare cause of posthepatectomy jaundice. It should be suspected in patients having posthepatectomy hyperbilirubinemia without other signs of liver failure. Steroid therapy can be considered for the treatment of PNH in such cases.     

FLAER检测及其在阵发性睡眠性血红蛋白尿症诊断中的意义

目的探讨荧光标记的嗜水气单胞菌溶素变异体(FLAER)检测在阵发性睡眠性血红蛋白尿症(PNH)诊断中的意义,并与传统的CD55、CD59测定进行比较。方法采用流式细胞术检测10例PNH、37例非PNH贫血患者外周血FLAER、CD55和CD59抗原的表达,对其结果进行比较。结果与非PNH贫血组相比,PNH患者外周血CD55、CD59缺失率和FLAER阴性率均明显增高(P<0.05)。10例PNH患者外周血粒细胞FLAER阴性率达(82.52±25.24)%,单核细胞FLAER阴性率达(79.84±19.86)%;与CD55、CD59的阴性率相比,PNH克隆数显著升高(P<0.05)。结论利用流式细胞术进行FLAER分析对PNH的诊断比CD55、CD59检测更加特异、敏感、直观,FLAER分析更能反映PNH克隆情况。     

阵发性睡眠性血红蛋白尿症患者骨髓正常及异常造血细胞增殖及生存特性初探

目的：探讨阵发性睡眠性血红蛋白尿症（ＰＮＨ）患者正常及异常造血细胞的增殖及生存特性。方法：用ＣＤ５９单抗及羊抗鼠ＩｇＧ免疫磁珠将６例患者骨髓单个核细胞（ＢＭＭＮＣ）分选为ＣＤ５９＋及ＣＤ５９－两群，分别进行体外培养并与正常对照比较。结果：ＰＮＨ患者ＣＤ５９＋及ＣＤ５９－ＢＭＭＮＣ的体外增殖及生存能力均弱于正常ＢＭＭＮＣ；患者体内“正常”的ＣＤ５９＋ＢＭＭＮＣ生长能力反较异常的ＣＤ５９－细胞显著降低；患者ＣＤ５９＋细胞培养后出现ＣＤ５９抗原的丢失，正常对照则无此改变。结论：ＰＮＨ患者ＢＭＭＮＣ中ＣＤ５９－的异常造血细胞具有相对的生长优势，ＣＤ５９＋的ＢＭＭＮＣ并非真正“正常”，可能存在尚未明了的某种缺陷；ＰＮＨ发病机制复杂，异常细胞除可因ＰＩＧ－Ａ基因突变产生外，还可能因ＧＰＩ蛋白的丢失而产生。     

Cardiopulmonary bypass surgery in a patient with paroxysmal nocturnal haemoglobinuria

Paroxysmal nocturnal haemoglobinuria (PNH) is a rare acquired haemolytic anaemia. Cardiac bypass surgery in patients with PNH may be complicated by aggravation of haemolysis in addition to increased risk of infection, renal failure, bleeding and thrombosis. We describe a case of uncomplicated cardiopulmonary bypass surgery for aortic valve replacement and aortoplasty in a patient with PNH and discuss some recommendations to reduce the risk of peri-operative complications.     

MR of the kidneys,liver, and spleen in paroxysmal nocturnal hemoglobinuria

The magnetic resonance (MR) findings in the liver, kidneys, and spleen in eight patients with paroxysmal nocturnal hemoglobinuria (PNH) were retrospectively reviewed to determine whether characteristic features could be demonstrated. Eight patients underwent abdominal MR examinations by gradient echo sequences (seven patients), spin-echo sequences (seven patients), and inversion recovery (one patient). Signal intensities of the kidneys, liver, and spleen were visually evaluated. Autopsy and liver biopsy correlation were available in one case each. Renal signal intensity was decreased in all eight patients by either gradient-echo or T2-weighted sequences and in the single inversion recovery sequence. Hepatic signal intensity was decreased in three of eight patients on spin- and gradient-echo images. Splenic signal intensity was decreased in three of eight patients on spin- and gradient-echo images, and in two of these was manifest as focal low signal spots (Gamna-Gandy bodies). While the signal intensity in the renal cortex is typically decreased in patients with PNH, signal intensities in the liver and spleen are variable. Low signal intensity in the kidneys is due to hemosiderin deposition resulting from intravascular hemolysis, whereas low signal intensity in the liver or spleen may be due to either transfusion siderosis, or as a consequence of hepatic or portal venous thrombosis.     

CD55/CD59缺陷检测及其在阵发性睡眠性血红蛋白尿诊断中的意义

目的：应用外周血红细胞CD55和CD59的检测并结合相关检验，建立有效的诊断和鉴别诊断阵发性睡眠性血红蛋白尿(PNH)的实验体系。方法：运用流式细胞术检测10例PNH患外周血红细胞和粒细胞的CD55和CD59，并分别对缺陷红细胞作激光散射分析(FS)及FS／CD55和FS／CD59双参数分析，结合溶血性贫血(溶贫)相关其他检验，作出PNH诊断。结果：5例PNH发作期患酸溶血试验呈阳性，CD55和CD59缺陷红细胞在流式细胞术检测中具有特征性的改变；5例PNH缓解期酸溶血试验等无明显改变，患外周血CD55和CD59缺陷红细胞的数量较少。运用流式细胞术分别作红细胞FS／CD55和FS／CD59双参数分析，发现CD59缺陷与红细胞FS具有相关性。正常红细胞与缺陷红细胞的FS分布存在明显差异。部分再生障碍性贫血患外周血也存在PNH样细胞，但FS／CD59检测结果与PNH患具有不同特征。结论：流式细胞术检测外周血红细胞CD55和CD59缺陷结合溶血性贫血的常规检验可对PNH作出较明确的诊断和鉴别诊断。     

Widespread abdominal venous thrombosis in paroxysmal nocturnal hemoglobinuria diagnosed on CT

Paroxysmal nocturnal hemoglobinuria is a rare disorder characterized by pancytopenia. One of the main manifestations of this disease is development of widespread life-threatening venous thrombosis, which may involve multiple abdominal veins. We describe two patients with paroxysmal nocturnal hemoglobinuria with clinically unsuspected portal, splenic, and mesenteric venous thromboses that were diagnosed on computed tomography. This complication should be clinically suspected in patients suffering from paroxysmal nocturnal hemoglobinuria who present with abdominal pain, and it should be sought by the radiologist on pre- and postcontrast computed tomography. Received: 3 October 2000/Accepted: 15 November 2000     

用流式细胞术检测CD55及CD59表型对诊断阵发性睡眠性血红蛋白尿的意义

目的：探讨用流式细胞术检测免疫表型对诊断阵发性睡眠性血红蛋白尿(paroxysmal noctur—nal hemoglobinuria，PNH)的意义。方法：用荧光标记分化群(cluster of differentiation，CD)中的CD55、CD59的单克隆抗体，采用流式细胞术测定25名正常人、28例PHN患者外周中性粒细胞和红细胞膜抗原的表达。结果：PNH患者中性粒细胞CD55、CD59，红细胞CD59表达率较正常人明显降低，且与疾病的严重程度相关。结论：用流式细胞术检测CD55、CD59表型是目前诊断PNH的较直接而又特异、敏感的方法。