The pathological mechanism of paroxysmal nocturnal hemoglobinuria:an update research

阵发性睡眠性血红蛋白尿症(PNH)是一种获得性造血干细胞克隆性疾病,其病理机制主要是位于X染色体上的PIG-A基因突变,导致血细胞膜表面糖化磷脂酰肌醇(GPI)锚连蛋白的减少或缺乏,从而使血细胞对补体的敏感性增强而发生血管内溶血。PIG-A基因突变本身并不能赋予PNH克隆增殖优势,目前提出PNH克隆得以扩增的3种机制:(1)GPI-细胞逃逸免疫攻击;(2)PIG-A基因突变使GPI-细胞获得抗凋亡特性;(3)二次基因突变学说,如EGR-1及WT1基因等。     

Corticosteroids therapy in paroxysmal nocturnal hemoglobinuria

We evaluated the efficacy of alternate day, high dose prednisolone for the treatment of paroxysmal nocturnal hemoglobinuria (PNH). Nineteen patients were included. Thirteen were men and six were women, aged between 13-56 years. Eleven patients improved, eight with good response and three with fair response. Eight patients were non-responders. Responders had gradual improvement in the hemoglobin level, but none achieved a normal hemoglobin level. Age at diagnosis, sex, initial hemoglobin, white count, and percentage of a positive Ham's test had no apparent bearing on treatment outcome. A prolonged interval from diagnosis to prednisolone treatment decreased the chance of a favorable hematologic response to therapy. Age at the treatment in non-responders was higher than responders. Responders had higher numbers of colonies derived from BFU-E and CFU-GM both in the blood and bone marrow than non-responders although the differences did not achieve statistical significance. These data indicate that alternate day, high dose prednisolone therapy is effective in some patients with PNH.     

Fc III receptors (FcRIII) on granulocytes: a specific and sensitive diagnostic test for paroxysmal nocturnal hemoglobinuria (PNH).

The FcRIII on human granulocytes is a glycosyl-phosphatidylinositol-anchored membrane protein. In PNH, proteins with this type of membrane linkage are known to be deficient on blood cells. The purpose of this study was to assess the diagnostic value of flow cytometric FcRIII quantification on granulocytes in PNH. Immunofluorescence measurements were performed in 105 patients, including 7 patients with PNH, 16 patients with aplastic anemia, and 12 with myelodysplastic syndrome, by a whole blood immunofluorescent staining procedure using monoclonal antibodies to FcRIII. In all 7 PNH patients and in 3 patients with aplastic anaemia, a distinct FcRIII-deficient granulocyte population of variable size was found. None of the remaining patients showed a similar population of FcRIII-deficient granulocytes. Quantification of FcRIII-deficient neutrophils is shown to be a highly specific and sensitive diagnostic test for PNH. It is easy, fast and highly reproducible and, therefore, suitable for routine diagnostic and follow-up studies in PNH patients and patients with aplastic anemia.     

The lipids of the erythrocyte in paroxysmal nocturnal hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) is a disorder characterized by the production of abnormal erythrocytes (PNH-E). The PNH-E undergoes early intravascular destruction which appears to be related to an intrinsic membrane defect that results in extreme sensitivity to lysis by complement. The lipids of the PNH-E have been evaluated because of the variable results reported in the past. This study shows a normal content of cholesterol and lipid phosphorus with a normal distribution of the phosopholipids except for a slight increase in lysophosphatidyl choline (LPC) when measured using the complete lipid extract of the PNH-E. Fractionation of the lipid extract over a silicic acid column produced an alteration in the distribution of the phospholipids, with LPC and sphingomyelin increasing, and the other phospholipds decreasing. These alterations were seen only when the phospholipids were fractioned over a silicic acid column and were clearly an in vitro phenomenon. The levels of plasmalogen and malonaldehyde were normal, unlike those seen with oxidant stress. Fatty acid analysis of the phospholipids showed small but consistent changes: increased 16:0 and decreased 18:2. The total glycosphingolipids were slightly decreased in the patients with severe PNH. The results support and extend previous lipid data indicating abnormalities in the phospholipids of the PNH-E. The alterations of the phospholipids with fractionation correlate with previous whole cell data that suggest lipid instability in the PNH-E.     

再生障碍性贫血-阵发性睡眠性血红蛋白尿综合征与典型阵发性睡眠性血红蛋白尿症的临床对照研究

目的　研究再生障碍性贫血 -阵发性睡眠性血红蛋白尿综合征 (AA PNH综合征 )与典型阵发性睡眠性血红蛋白尿症 (PNH)临床特征的异同 ,加深对AA PNH综合征的认识。方法　回顾分析了 2 8例AA PNH综合征和 5 1例典型PNH的临床表现、实验室检查及治疗反应 ,并进行了对照研究。结果　AA PNH综合征与典型PNH相比 :①血栓形成、黄疸、肝脾肿大等临床表现均较轻。②网织红细胞虽较低 ,但仍高于正常 ;骨髓涂片及活检多表现为增生减低 ,但红系比例不低 ;③各溶血指标检查阳性率均较低 ,但CD5 5、CD5 9表达异常的检出率为10 0 % ,且其在红细胞、粒细胞、淋巴细胞中表达的百分率在两组患者中无明显差异。④免疫球蛋白、T细胞亚群的检测 ,两组患者均无异常。⑤两组患者对肾上腺糖皮质激素为主的治疗均反应良好。结论　AA PNH综合征虽临床表现有别于典型PNH ,但与典型PNH无本质区别 ;CD5 5、CD5 9的检测有助于提高AA PNH综合征的检出率     

Intestinal infarction caused by paroxysmal nocturnal hemoglobinuria

A patient with paroxysmal nocturnal hemoglobinuria of 14 years duration presented with severe abdominal pain and fever. On admission, his hematocrit had fallen to 19% from his usual level of approximately 30%, and stools were positive for occult blood. Dilated loops of small bowel with air fluid levels were noted on radiographs, and sonography revealed free intraperitoneal fluid. Several sections of gangrenous jejunum and ileum were resected at exploratory laparotomy, and mesenteric venous thromboses were present. This is the second report of pathologically proven intestinal infarction in a patient with paroxysmal nocturnal hemoglobinuria who has survived this abdominal emergency with surgical intervention. Although abdominal pain in patients with paroxysmal nocturnal hemoglobinuria has frequently been attributed to mesenteric venous thromboses, this has rarely been documented either during life or at autopsy.     

Treatment of paroxysmal nocturnal hemoglobinuria in the era of eculizumab

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, life-threatening and debilitating clonal blood disorder caused by an acquired mutation in the phosphatidylinositol glycan (PIG)-A gene. In pluripotent hematopoietic stem cells, this leads to a deficiency of glycosylphosphatidylinositol (GPI)-anchors and GPI-anchored proteins, including the complement regulators CD55 and CD59, on the surface of affected blood cells. PNH red blood cells are highly vulnerable to activation of complement and the formation of the membrane attack complex (MAC). The resulting chronic intravascular hemolysis is the underlying cause of PNH morbidities and mortality. Until recently, the treatment of PNH has been largely empirical and symptomatic with blood transfusions, anticoagulation, and supplementation with folic acid or iron. The only potentially curative treatment is allogeneic stem cell transplantation, but this has severe complications and high mortality and morbidity rates. A new targeted and disease-modifying treatment strategy is the inhibition of the terminal complement cascade with the humanized monoclonal anti-C5 antibody, eculizumab. This effectively inhibits MAC formation and intravascular hemolysis. Eculizumab has shown significant efficacy in controlled studies, with a marked decrease in anemia, fatigue, transfusion requirements, renal impairment, pulmonary hypertension, and risk of severe thromboembolic events, ultimately resulting in improving quality of life and survival.     

Recent advances in paroxysmal nocturnal hemoglobinuria: From the biology to the clinic

PNH is now known as an acquired, clonal disorder of the hematopietic stem cells caused by somatic mutation in the X-linked PIG-A gene encoding a protein involved in the synthesis of the glycosylphosphatidylinositol (GPI) anchor by which many proteins are attached to the membrane. Since the past few years, significant advances in the knowledge of the biology of this rare disease have been done. Similarily on the clinical ground, large series of patients with PNH have been published recently, providing estimates of factors affecting survival and of long term follow-up of significant numbers of patients. In this overview we focus on recent advances in the biology and the clinical aspects of this disease, and more importantly try to underline the numerous aspects of yet un-answered questions.     

Coexistence of paroxysmal nocturnal hemoglobinuria and chronic lymphocytic leukemia

A man with paroxysmal nocturnal hemoglobinuria and a lymphoproliferative disorder is described. The latter condition evolved into a typical picture of chronic lymphocytic leukemia. The significance of this association is obscure, but treatment of one or the other disease was clearly not an etiologic factor in this concurrence.     

Abnormal erythrocyte fragmentation and membrane deformability in paroxysmal nocturnal hemoglobinuria

Hemolysis in paroxysmal nocturnal hemoglobinuria (PNH) is considered to be a result of an intrinsic membrane defect. This defect may result in abnormal material properties of PNH erythrocytes. To examine this hypothesis, fragmentation failure, and membrane deformability were assessed in the absence of complement by micropipette techniques. Membrane viscosity was determined by observing relaxation of deformed cells. Results show a bimodal distribution of force for membrane failure, membrane viscoelasticity, and elastic shear modulus. One population requires significantly less force for fragmentation, mean 0.56 X 10(-6) dyne; has increased membrane viscosity, mean 0.205 X 10(-2) dyne sec/cm; and has decreased elastic shear modulus, mean 0.56 X 10(-2) dyne/cm. A second population resembles control with fragmentation force, mean 1.19 X 10(-6) dyne, control 1.05 X 10(-6) dyne; membrane viscosity, mean 0.112 X 10(-2) dyne/cm, control 0.102 X 10(-2) dyne sec/cm; elastic shear modulus, mean 0.70 X 10(-2) dyne/cm, control 0.78 X 10(-2) dyne/cm. The percent of cells with abnormal material properties corresponds to the percent of PNH III cells determined by complement lysis. Thus, the hemolysis attributed to an abnormal clone of erythrocytes in PNH is associated with an intrinsic membrane abnormality which predisposes to lysis.     

A patient with paroxysmal nocturnal hemoglobinuria, T cell large granular lymphocyte clonal expansion, and monoclonal gammopathy of undetermined significance

Paroxysmal nocturnal hemoglobinuria (PNH) has been described in association separately with T cell large granular lymphocyte (LGL) clonal expansions and plasma cell dyscrasias. We describe a patient with anemia related to hemolytic PNH, with concurrent T cell LGL oligoclonal expansion and IgG lambda monoclonal gammopathy of undetermined significance. Peripheral blood flow cytometry revealed decreased expression of CD55 and CD59 on erythrocytes and decreased expression of CD55 and CD66 on neutrophils. An LGL population was present in the peripheral blood and was characterized as oligoclonal by polymerase chain reaction-based analysis of the T cell receptor gamma-chain variable region. Serum protein electrophoresis with immunofixation showed a low level IgG lambda monoclonal protein. We describe the diagnostic evaluation of this patient and provide a brief review of the reported associations among PNH, LGL clonal expansion, and monoclonal gammopathy.     

阵发性睡眠性血红蛋白尿并发缺血性肠病临床特点分析

阵发性睡眠性血红蛋白尿症（paroxysmal nocturnal hemoglobinuria,PNH）是一种罕见的获得性造血干细胞疾病。PNH胃肠道受累非常少见。本研究旨在总结和分析PNH并发缺血性肠病的临床特点。收集并总结自2010年1月至2020年12月在北京协和医院诊断的6例PNH 并发缺血性肠病患者的临床资...     

Production paroxysmal nocturnal hemoglobinuria-like red blood cells by tea

Normal human red cells incubated with saline extracts of tea develop paroxysmal nocturnal hemoglobinuria-like defects as demonstrated by positive acid and sucrose hemolysis tests. All of a variety of tea preparations tested provoked a sensitivity to complement-dependent hemolysis and, with one exception, a moderate decrease in red cell acetylcholinesterase activity. Complement-dependent hemolysis in teaincubated red cells was inhibited by antisera to C3 and C3 activator, but not by antisera to C4. This suggests that incubation with tea may alter the red cell membrane in a way that specifically potentiates the lytic effects of the alternate pathway of complement, but not the classic pathway. Leupeptin, a protease inhibitor, also prevented complement-dependent hemolysis of red cells incubated with tea. Although the clinical consequences of these observations are unknown, the study was initiated following a report of a young male who had developed an acute limited intravascular hemolytic episode following ingestion of large quantities of a herbal tea.     

Lactic acidosis secondary to severe anemia in a patient with paroxysmal nocturnal hemoglobinuria

A patient with paroxysmal nocturnal hemoglobinuria developed lactic acidosis associated with severe anemia. The lactic acidosis corrected after blood transfusion. In the absence of shock, sepsis, or other identifiable causes of lactic acidosis, the severe anemia (hemoglobin 1.2 g/dl) appeared to be the primary etiologic factor. Am. J. Hematol. 55:110-111, 1997. © 1997 Wiley-Liss, Inc.     

COVID19 infection in a patient with paroxysmal nocturnal hemoglobinuria: A case report

Introduction:Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired, life-threatening hemopoietic stem cell disorder characterized by the triad of hemolytic anemia, thrombosis, and impaired bone marrow function. Evidence suggests that severe outcomes in COVID19 infection are attributed to the excessive activation of the complement cascade leading to acute lung injury and associated is with an increased prothrombotic state.Patient concerns:A 27-year-old Caucasian man with PNH presented to the Emergency Department of our hospital with acute onset shortness of breath, cough and blood in urine.Diagnosis:The patient was diagnosed with acute hemolytic exacerbation of PNH complicated with moderate COVID19 pneumonia.Outcomes:The patient was initiated with an anticoagulant unfractionated heparin, dexamethasone, and cefuroxime injection. His symptoms quickly resolved, and he was discharged after 5 days.Conclusion:The complement system activation is a critical component in the sequalae of COVID19 infection. Evidence suggests that severe outcomes in COVID19 infection are attributed to the excessive activation of the complement cascade leading to acute lung injury and associated is with an increased prothrombotic state. Notably, C5a concentration was noted to be higher in patients with COVID19 infection. The use of complement inhibitors to attenuate immune mediated damage in COVID19 nevertheless represents a very interesting theoretical approach. However, careful consideration as to which patients may benefit will be required and the outcome of clinical trials needed.     

阵发性睡眠性血红蛋白尿患者外周血细胞CD47的表达

目的:通过研究阵发性睡眠性血红蛋白尿症(PNH)患者外周血细胞CD47的表达,探讨CD47在PNH发病机制中的作用。方法:选取PNH患者8例,正常对照组15例,以逆转录-聚合酶链反应异源双链分析银染法进行PIG-A基因检测,流式细胞术检测外周血细胞表面CD47、CD59的表达。结果:6例PNH患者PIG A基因第2外显子有碱基变异,其余2例未发现异常;PNH患者外周血红细胞、粒细胞CD47表达阳性率及平均荧光强度比正常对照组均减低(P<0．05)。结论:PNH患者外周血细胞表面CD47表达减少,CD47的表达与PNH发病机制可能有关。     

Donor stem cell-derived paroxysmal nocturnal hemoglobinuria after umbilical cord blood transplantation

Donor cell-derived hematological disorder (DCHD) is a rare complication of allogeneic hematopoietic stem cell transplantation (HSCT). The number of reports of DCHD has been increasing in the last decade, which likely reflects the growing number of HSCTs and the improved ability to identify the donor cell origin. Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired hematological disorder arising in the context of clonal expansion of hematopoietic stem cells harboring a somatic mutation in phosphatidylinositol glycan anchor biosynthesis, class A. We report here a patient with adult T-cell leukemia/lymphoma, who developed PNH 7 years after umbilical cord blood transplantation. The patient has maintained complete remission with full-donor chimerism after HSCT. Thus, PNH was derived from stem cells of donor origin. The immature immune environment in the recipient after cord blood transplantation might have contributed to the rapid clonal expansion for neonatal stem cells in cord blood to develop typical symptomatic PNH in a short period. To the best of our knowledge, this is the first report in the literature of a case of PNH that developed in donor stem cells after HSCT.     

The aplastic anemia-paroxysmal nocturnal hemoglobinuria syndrome

Occasionally it is difficult to differentiate paroxysmal nocturnal hemoglobinuria (PNH) from idiopathic aplastic anemia in patients who present with pancytopenia and an aplastic bone marrow. Patients with PNH may not have an abnormal acid hemolysis test, and patients with aplastic anemia may present with evidence of abnormal sucrose lysis, acid hemolysis, and antibody-mediated complement hemolysis. Demonstration of a population of red blood cells which are highly susceptible to antibody-mediated complement lysis makes a diagnosis of PNH probable. Donor red blood cell survival studies, which distinguish intracorpuscular from extracorpuscular hemolytic disorders, permit differentiation of the two disorders.