Increased eculizumab requirements during pregnancy in a patient with paroxysmal nocturnal hemoglobinuria: case report and review of the literature

Paroxysmal nocturnal hemoglobinuria (PNH) results from reduced complement regulatory proteins on hematopoietic cells, predisposing patients to intravascular hemolysis, thrombophilia, and cytopenias. Women diagnosed in pregnancy can experience significant maternofetal complications. Trials of eculizumab in PNH excluded pregnant women. Here, we report the first Canadian patient taken through pregnancy on eculizumab.     

A platelet and granulocyte membrane defect in paroxysmal nocturnal hemoglobinuria: usefulness for the detection of platelet antibodies

The tendency of platelets and leukocytes to lyse after their interaction with antibody and complement was studied by measuring the release of (51)Cr from cells labeled with this isotope. Platelets from six patients with paroxysmal nocturnal hemoglobinuria (PNH) were 15-230 times more sensitive to antibodies and 10-32 times more sensitive to complement than normal platelets or platelets from patients with other types of thrombocytopenic or hemolytic disorders. Mixed white blood cell (WBC) preparations from patients with PNH were 3-20 times more sensitive to anti-WBC antibodies and 5-10 times more sensitive to C' than were WBC preparations from normal subjects, but PNH lymphocytes showed normal immunologic reactivity. PNH platelets, like PNH erythrocytes, lysed more readily than normal platelets in acidified serum and in media of reduced ionic strength, but these characteristics were not demonstrable with PNH WBC's under the conditions of study. In PNH, platelets appear to comprise a single population with respect to their sensitivity to immune lysis, yet their survival time as measured with (51)Cr falls within normal limits. PNH granulocytes likewise appear to consist of a single, uniformly sensitive population.It is concluded that, in PNH, platelets and granulocytes share the membrane defect characteristic of erythrocytes in this disorder. These observations support the concept that PNH arises as the result of a somatic mutation in a primitive cell capable of differentiating into erythroblast, myeloblast, and megakaryoblast lines. PNH platelets or enzymatically treated normal platelets permit the detection of some types of platelet antibodies in dilutions up to 2000-fold greater than is possible with currently available methods, a finding suggesting that the immune lysis technique will prove useful for the study of platelet immunology.     

Characterization of circulating and cultured Tfh-like cells in sickle cell disease in relation to red blood cell alloimmunization status

BackgroundPeople living with sickle cell disease (SCD) are prone to red blood cell (RBC) alloimmunization. We hypothesized that subjects with alloantibodies (responders) would have differences in circulating T-follicular helper (Tfh)-like cells compared to subjects without alloantibodies (non-responders).Materials and methodsPeripheral blood mononuclear cells were collected from 28 subjects, including those with SCD and controls. Circulating CD4 T-cell subsets were first evaluated at baseline. CD4 T-cell subsets were also evaluated after naïve CD4 T-cells were differentiated into Tfh-like cells following in vitro culture with CD3/CD28 beads, IL-7, IL-12, and Activin A. Transfusion and alloantibody histories were extracted from the electronic medical record.ResultsNon-responders had a lower percentage of CD45RA negative Tmemory cells than responders or controls (p<0.05). Notably, there were no differences in circulating Tfh-like cells between any group. However, naïve CD4 T-cells from subjects with SCD were more likely to express CXCR5 after in vitro culture than cells from controls. After culture, CXCR5 expressing cells from responders were more likely to express PD1 and ICOS (16.43 %, sd. 20.23) compared to non-responders (3.69 %, s.d. 3.09) or controls (2.78 %, s.d. 2.04).DiscussionThe tendency for naïve CD4 T-cells from responders to differentiate into Tfh-like cells after in vitro culture may suggest these cells are prepared to assist B-cells with antibody production regardless of antigen specificity. Further studies are needed, but it is possible that these results may explain why some responders form RBC alloantibodies with multiple specificities, in addition to RBC autoantibodies and HLA alloantibodies.     

Observations on plasma and red cell lipids in hereditary spherocytosis

Plasma lipids and red cell lipids were determined in hereditary spherocytosis (HS), 15 unsplenectomized and eight splenectomized patients. Plasma lipids (cholesterol: total, free and high density lipoproteins, free fatty acids, and phospholipids) were markedly decreased in HS, especially in the unsplenectomized patients. Concomitantly, red cell membrane lipids (free cholesterol and phospholipids: total, phosphatidyl ethanolamine, sphingomyelin, phosphatidyl choline, and lysophosphatidyl choline) were also diminished. The plasma lipids stay low even after splenectomy although partially restored. Thus, decreased membrane surface, a hallmark of HS, could be partly attributed to the diminished membrane lipids induced by plasma lipid abnormalities in the patients.     

阵发性睡眠性血红蛋白尿症患者骨髓中正常及异常造血干/祖细胞含量分析

OBJECTIVE: To explore the contributive role of CD34+ cell amount in pathogenesis of clonal dominance in paroxysmal nocturnal hemoglobinuria (PNH). METHODS: Bone marrow nuclear cells (BMNCs) were doubly labeled by PE-conjugated anti-CD59 monoclonal antibody (McAb) and FITC-conjugated anti-CD34 McAb, and CD34+ cells contained in different cell populations were determined by flow cytometry. RESULTS: 1. CD34+ cells mainly appeared in window A (containing mainly of lymphocytes) and window D (composed of blasts, other immature cells and monocytes) in both normal controls and PNH patients. 2. The numbers of CD34+ cells in normal controls were (3,701 +/- 896)/10(5) cells and (11,373 +/- 1,574)/10(5) cells in window A and window D, respectively. Compared with normal controls, PNH patients possessed significantly decreased number of CD34+ cells [(1,215 +/- 749)/10(5) cells and (6,420 +/- 2,337)/10(5) cells in window A and window D, respectively]. 3. In normal controls, nearly all CD34+ cells in windows A and D expressed CD59 antigen (99.2% +/- 1.0% in A and 98.7% +/- 0.8% in D), whereas in PNH patients, the CD34+ cells clearly showed two immunophenotypes of CD34+CD59+ and CD34+CD59- with the latter being predominant in both window A and window D(CD59- cells constituting 79.3% +/- 15.5% and 85.9% +/- 7.8% of CD34+ cells, respectively). 4. The amounts of CD34+ cells in CD59+ populations [(463 +/- 276)/10(5) cells in window A and (3,841 +/- 1,188)/10(5) cells in window D] reduced to a greater extent than that in CD59- population [(2,603 +/- 2,084)/10(5) cells in window A and (7,105 +/- 2,739)/10(5) cells in window D]. CONCLUSION: Hematopoietic stem/progenitor cells in BMNCs of PNH patients are markedly decreased. Reduction of CD34+ cells in CD59+ cell population is even more obvious than that in CD59- population. The dominance of the abnormal clone in hematopoiesis might be a relative one in the setting of severely impaired normal hematopoiesis.     

Delayed hemolytic transfusion reactions in sickle cell disease: simultaneous destruction of recipients' red cells

BACKGROUND: Bystander hemolysis may be defined as the destruction of antigen-negative red cells during immune hemolysis, such as delayed hemolytic transfusion reaction (DHTR). Although many have suspected that bystander hemolysis does occur, that phenomenon is very difficult to document. STUDY DESIGN AND METHODS: Five patients with sickle cell disease (SCD) who underwent exchange transfusion and subsequently experienced a DHTR were retrospectively evaluated. Serial samples were examined for complete blood counts, the percentage of hemoglobin A and S, and the percentage of reticulocytes. The total red cell count and the percentage of hemoglobin S were used to calculate the hemoglobin S red cell count. The patients' profiles were compared to proposed models. RESULTS: DHTRs due to anti-E, -S, -Fy(a), or -Jk(a) or serologically undetectable antibodies were identified 7 to 19 days after exchange transfusion. All patients had a significant decrease in hemoglobin A red cells; 56.4 to 94.7 percent of hemoglobin A red cells were hemolyzed. Patients 4 and 5 had a decrease in hemoglobin S red cells which indicated the destruction of autologous red cells during DHTR. The evidence for bystander hemolysis was particularly convincing in Patient 5, because there was a substantial decrease in hemoglobin S red cells despite a reticulocyte production index of 2.2 percent at the nadir of the DHTR. CONCLUSION: Hemoglobin S provides a biologic marker for monitoring autologous red cell loss in sickle cell patients. We have shown one patient with clinical evidence of bystander hemolysis complicating a DHTR.     

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.     

Improved method for automated red cell exchange in sickle cell disease

An improved method for intermittent-flow erythrocytapheresis in patients with sickle cell disease is reported. The method, a modification of the standard red cell exchange procedure for the Haemonetics 30S unit, dilutes with physiologic saline the patient's blood as it flows from the draw line and before it reaches the centrifugation bowl. The blood dilution (approximately 1.6 parts saline to 1 part blood) is used only during the first two passes, when the proportion of sickle erythrocytes in the patient's blood is still high. Only that amount of bowl supernatant (saline-diluted plasma) necessary to maintain extracorporeal volume below 500 ml is returned to the patient. The method described largely prevents the clumping of sickle erythrocytes in the centrifugation bowl, a complication frequently encountered with the Haemonetics 30S unit. Thus, changing the bowl between passes is avoided. Furthermore, the sickle red cells can be collected with the first pass and cryopreserved for possible future uses including the option of autotransfusion.     

Delayed hemolytic transfusion reaction in sickle cell disease patients: evidence of an emerging syndrome with suicidal red blood cell death

BACKGROUND: Delayed hemolytic transfusion reaction (DHTR) is a life-threatening complication in sickle cell disease (SCD) characterized by recurrence of disease complications, recipient red blood cell (RBC) destruction, and frequently no detectable antibody. Phosphatidylserine (PS) exposure signs suicidal RBC death or eryptosis and is involved in vasoocclusive crisis (VOC).
STUDY DESIGN AND METHODS: Transfusion was monitored in 48 SCD patients for up to 20 days. PS exposure was evaluated in vivo on patient RBCs (PS-RBCs) at five time points and in vitro after incubation of donor RBCs with pretransfusion plasma.
RESULTS: Three VOC patients displayed DHTR with recurrent SCD features and no detectable antibody in two cases. In vitro, PS-RBC percentage was significantly increased by incubating donor RBCs with pretransfusion plasma samples from DHTR patients with no detectable antibody. No such increase was observed with samples from other patients. This result indicates that donor RBCs may be damaged by the environment of SCD patients, increasing the physiologic clearance of apoptotic RBCs. In vivo, PS-RBC percentage increased in all three cases after destruction of transfused RBCs, indicating that DHTR induces PS-RBCs and, possibly, subsequent VOC and autologous RBC destruction.
CONCLUSION: This study clearly demonstrates that DHTR can occur in the absence of detectable antibody. In these cases, a mechanism of excessive eryptosis is proposed.     

Older red cell units are associated with an increased incidence of infection in chronically transfused adults with sickle cell disease

Background

In adults with sickle cell disease (SCD), the effects of the red cell storage lesion are not well defined. The objectives of this study were to: (1) describe the distribution of storage ages provided to adults with SCD, and (2) evaluate clinical outcomes associated with storage age.

Red cell transfusion in paediatric patients with thalassaemia and sickle cell disease: Current status,challenges and perspectives

Notwithstanding the high safety level of the currently available blood for transfusion and the decreasing frequency of transfusion-related complications, administration of labile blood products to paediatric patients still poses unique challenges and considerations. The incidence of thalassaemia and sickle cell disease in the paediatric population may be high enough under specific racial and geographical contexts. Red cell transfusion is the cornerstone of β-thalassaemia treatment and one of the most effective ways to prevent or correct specific acute and chronic complications of sickle cell disease. However, this life-saving strategy comes with its own complications, such as additional iron overload, alloimmunization and haemolytic reactions, among others. In paediatrics, the dependency of the transfusion outcome upon disease and other recipient characteristics is more prominent compared with the adults, owing to differences in developmental maturity and physiology that render them more susceptible to common risks, exacerbate the host response to transfused cells, and modify the type or the clinical severity of the transfusion-related morbidity. The adverse branch of red cell transfusion is likely the overall effect of several factors acting synergistically to shape the clinical phenotype of this therapy, including inherent donor/blood unit variables, like antigenicity, red cell deformability and extracellular vesicles, as well as recipient variables, such as history of alloimmunization and inflammation level at time of transfusion. This review focuses on paediatric patients with β-thalassaemia and sickle cell disease as a recipient group with distinct transfusion-related characteristics, and introduces new concepts for consideration, not adequately studied and elucidated so far.     

Complete neurological recovery from fat embolism syndrome in sickle cell disease after sequential red cell exchange transfusion and therapeutic plasma exchange

Fat embolism syndrome in sickle cell disease is associated with great mortality, while more than half of survivors suffer severe neurological sequelae. Release of fat droplets leads to obstruction of the microcirculation as well as generation of proinflammatory cytokines that can cause direct tissue injury. Red cell exchange transfusion can be life-saving but the addition of therapeutic plasma exchange may further improve outcomes by removing such inflammatory mediators. Here, we describe the case of a 27-year-old male patient with sickle cell anaemia presenting with typical features of fat embolism syndrome including neurological involvement with greatly reduced level of consciousness. MRI of his brain showed multiple widespread microhemorrhages giving the characteristic "star field" pattern but also a cytotoxic lesion of the corpus callosum, known to be the result of direct neurotoxicity by proinflammatory cytokines. The patient underwent emergency red cell exchange transfusion leading only to modest clinical improvement but fully regained consciousness after three cycles of therapeutic plasma exchange. This case highlights the deleterious effect of the hyperinflammatory state characteristic of many sickle cell complications and supports further exploring the potential benefit from plasma exchange as an adjunct to red cell exchange in order to remove proinflammatory cytokines during acute complications of sickle cell disease.     

Preparation of packed red blood cell units in the blood bank: Alteration in red blood cell deformability

BackgroundDonated blood is stored in the blood bank as packed red blood cell units. In the process of packed cells preparation, the red blood cells (RBCs) are subjectedto high level of shear stress, which can induce alterations in their properties.In the present study, we examined the effect of packed RBCs preparation (which included leuko-filtration) on red cell deformability.MethodsBlood samples were collected from 25 healthy donors and from corresponding units of packed RBCs. The portion of undeformable cells (%UDFC) was determined for each sample.ResultsThe median value of %UDFC was equal to 6.75 ± 0.70 %, for freshly-donated RBCs, and to 6.36 ± 0.51 %, for packed cells. Wherein, %UDFC may increase or decrease following packed cells preparation, depending upon the initial portion of undeformable cells.ConclusionLikely, exposure of RBCs to high shear stress, during packed cells preparation, induces opposing effects: (a) removal/destruction of rigid (undeformable) cells, thereby reducing their total amount (i.e., decreasing the %UDFC) on the one hand, and (b) mechanical damage to the cell membrane and subsequent reduction of the cell deformability (thereby increasing the %UDFC) on the other. As a consequence, the final impact of packed cells preparation is primarily determined by the initial state of erythrocytes in the blood of the donor.     

慢性胃炎和十二指肠球部溃疡红细胞免疫功能的变化

目的 探讨胃疾病与红细胞免疫功能变化的研究.方法 采用花环法测定红细胞C3b受体花环率(RBCC3bRR)及免疫复合物花环率(RBCICR),对103例慢性胃炎(慢性胃炎组)和75例十二脂肠球部溃疡患者(十二指肠球部溃疡组)及30名健康者(正常对照组)进行红细胞免疫功能检测.结果 正常对照组、慢性胃炎组、十二指肠球部溃疡组RBCC3bRR分别为(20.83±5.16)％、(16.26±5.17)％、(13.65±5.19)％,RBCICR分别为(7.63±4.09)％、(10.59±4.45)％、(10.04±4.13)％.2项指标慢性胃炎组和十二指肠球部溃疡组均低于正常对照组(t分别为4.963、6.070,P均＜0.01),RBCICR分别高于正常对照组(t分别为3.262、3.456,P＜0.05或P＜0.01).HP阴性慢性胃炎与HP阴性十二指肠球部溃疡、HP阳性慢性胃炎与HP阳性十二指肠球部溃疡分别比较RBCC3hRR和RBCICR差异均无统计学意义(P均＞0.05);慢性胃炎及十二指肠球部溃疡HP阳性RBCC3bRR明显低于HP阴性者(P＜0.05或P＜0.01),RBCICR明显高于HiP阴性者(P均＜0.01),HP根除后慢性胃炎和十二指肠球部溃疡患者RBCC3bRR,分别较治疗前明显升高(P＜0.05或P＜0.01).RBCICR分别较治疗前明显降低(P均＜0.01).结论 HP感染、慢性胃炎、十二指肠溃疡均可降低红细胞免疫功能.     

With a simple calculation,the fraction of platelets remaining can be used to estimate the residual hemoglobin S percentage in sickle cell disease patients undergoing automated red blood cell exchange

Objectives

Automated red blood cell exchange (RBX) is an important treatment for patients with sickle cell disease (SCD). Although not specifically targeted for removal, platelets (PLTs) are collected along with red blood cells during RBX. We sought to determine whether the pre- and post- RBX PLT counts could be used to derive the post-procedure hemoglobin S% (HgbS%).

Safety,tolerability, and outcomes of regular automated red cell exchange transfusion in the management of sickle cell disease

We report here our experience with regular automated red cell exchange transfusion for the management of chronic complications of sickle cell disease in 50 patients in our institution from June 2011 to December 2014. The mean sickle hemoglobin level was 44% and 8.5% pre‐ and post‐transfusion, respectively. Platelets were reduced by a mean 70% during the procedure with a count of less than 50 × 10⁹/l in 6% of cases. The alloimmunization rate was 0.065/100 units of red cells with no hemolytic reactions. Patients with no iron overload at baseline showed no evidence of iron accumulation with a mean liver iron concentration of 1.6 mg/g dry tissue and 1.9 mg/g dry tissue at baseline and 36 months, respectively. All six patients with pre‐existing iron overload and on chelation therapy, showed a gradual reduction of their liver iron concentration and two patients could discontinue chelation during the follow‐up period. Seventy percentage of patients who were on the programme for recurrent painful crises showed a sustained reduction in the number of emergency hospital attendances; the mean number of days in hospital for emergency treatment was 103 in the year prior to commencing ARCET and reduced to 62 (40%) after the first 12 months, 51 (50%) after 24 months, and 35 days (66%) after 36 months. J. Clin. Apheresis 31:545–550, 2016. © 2015 Wiley Periodicals, Inc.     

阵发性睡眠性血红蛋白尿症、再生障碍性贫血和骨髓增生异常综合征患者三种GPI-锚蛋白的表达及临床意义

目的　观察阵发性睡眠性血红蛋白尿症 (PNH)、再生障碍性贫血 (AA ,再障 )和骨髓增生异常综合征 (MDS)患者外周血粒细胞三种GPI 锚蛋白 (GPI AP)CD55、CD59和CD87的表达情况 ,测定血清可溶性尿激酶型纤溶酶原激活物受体 (su PAR)水平 ,探讨它们的临床意义。方法　PNH组 2 2例 ,其中4例合并血栓性疾病 ,5例为AA PNH综合征 ;再障组 30例 ,其中重型再障 9例 ,慢性再障 2 1例 ;MDS RA组 2 7例 ;健康对照组 2 0名。以流式细胞术检测外周血粒细胞CD55、CD59和CD87的表达 ,ELISA法检测血清su PAR。结果　 2 0名健康人外周血粒细胞三种GPI AP阳性比例均大于 90 % ,CD59稳定性最好。PNH组三种GPI AP的阳性比例均显著下降 ,血清su PAR水平显著升高 ,与正常对照组比较 ,均有显著性差异。其中 ,频发组较不发作组三种GPI AP的表达率均明显降低 ,CD55的差异有显著性。PNH患者中 ,血栓阳性组较血栓阴性组CD87的表达率降低有显著性 ,血清su PAR水平显著升高。再障组粒细胞CD87表达率较正常对照组显著降低。 5例AA PNH综合征患者三种GPI AP的表达率与PNH患者比较 ,均无显著性差异 ;与再障患者比较 ,均显著降低。MDS RA组三种GPI AP的表达率较健康对照组均无显著性差异。结论　以流式细胞术检测外周血粒细胞CD55、CD59和CD     

Therapeutic plasma exchange in the management of acute complications of sickle cell disease: A single centre experience

Sickle cell disease results in systemic inflammation even at steady state and this is accentuated during acute crises. The plasma of affected patients contains several proinflammatory cytokines as well as adhesion molecules and prothrombotic factors. This environment promotes further red cell sickling while many of these substances can cause direct tissue toxicity and end-organ damage. Even though red cell transfusion, whether simple or exchange, is the mainstay of treatment of severe acute complications, addition of therapeutic plasma exchange could potentially provide additional benefit by removing such harmful substances. Here, we describe two cases where therapeutic plasma exchange was used. The first involved a patient with the acute chest syndrome who despite adequate red cell exchange remained significantly hypoxic and in severe pain. We therefore proceeded to perform plasma exchange; this led to rapid clinical improvement and resolution of his symptoms. The second case involved a patient with intractable chest wall pain and impending acute chest syndrome; this patient also had a past history of hyperhaemolysis. The patient underwent therapeutic plasma exchange with very rapid resolution of the pain, avoidance of any respiratory deterioration and full recovery. We also give a brief summary of our previous experience using plasma exchange in patients with sickle cell disease. Plasma exchange was well tolerated with no adverse events in all cases we have treated, led to rapid resolution of pain irrespective of primary indication and in the majority of cases to a favourable clinical outcome.