A longitudinal analysis of paroxysmal nocturnal haemoglobinuria-type cells in patients with bone marrow failure: Results of a prospective multi-centre study in Japan.

To determine the prevalence and clinical relevance of glycosylphosphatidylinositol-anchored protein-deficient (GPI[-]) cell populations (paroxysmal nocturnal haemoglobinuria [PNH]-type cells) in patients with acquired aplastic anaemia (AA) or myelodysplastic syndrome (MDS), we prospectively studied peripheral blood samples of 2402 patients (1075 with AA, 900 with MDS, 144 with PNH, and 283 with other anaemia) using a high-sensitivity flow cytometry assay in a nationwide multi-centre observational study. PNH-type cells were detected in 52.6% of AA and 13.7% of MDS patients. None of the 35 patients with refractory anaemia (RA) with ringed sideroblasts or the 86 patients with RA with excess of blasts carried PNH-type cells. Among the 317 patients possessing PNH-type granulocytes, the percentage of PNH-type granulocytes increased by ≥10% in 47 patients (14.8%), remained unchanged in 240 patients (75.7%), and decreased by ≥10% in 30 patients (9.5%) during 3 years of follow-up. PNH-type granulocyte expansion occurred more frequently (27.1%) in the 144 patients who originally carried PNH-type granulocytes ≥1% than in the 173 patients with PNH-type granulocytes <1% (4.6%). This study confirmed that PNH-type cells are undetectable in authentic clonal MDS patients, and the presence of ≥1% PNH-type granulocytes predicts a higher likelihood of PNH-type cell expansion than with <1% PNH-type granulocytes.

[Japanese patient preferences between ravulizumab and eculizumab for the treatment of paroxysmal nocturnal hemoglobinuria].

Ravulizumab is the first long-acting complement inhibitor approved for paroxysmal nocturnal hemoglobinuria (PNH) treatment. We evaluated patient preference for ravulizumab or eculizumab among Japanese adults with PNH. The ALXN1210-PNH-301 (NCT02946463) and ALXN1210-PNH-302 (NCT03056040) studies included 23 Japanese adults who are enrolled in complement inhibitor treatment-naive and eculizumab (≥6 months) treatment. Patient preference was assessed using the PNH-specific patient preference questionnaire (PNH-PPQ©). Most patients preferred ravulizumab (19/23, 82.6%), none preferred eculizumab, and four (17.4%) reported no preference (χ2 test, p<0.005). The preference for ravulizumab was driven by its lower infusion frequency (every 8 weeks) compared with eculizumab (every 2 weeks). The included Japanese patients with PNH preferred ravulizumab because of its reduced infusion frequency, which increases activity planning ability, treatment convenience, and overall quality of life, as compared with eculizumab. These data provide useful insight into patient perspectives and may aid decision-making for PNH treatment.

Effectiveness of a case-based digital learning interprofessional workshop involving undergraduates in medical technology, radiological science, and physical therapy: A pre-post intervention study.

All healthcare professionals must understand information on a patient's biophysical functions, and it is important to educate professionals on how to use this information in an interprofessional team for diagnosis. However, there is little interprofessional education for students of medical technology and radiological science involved in biophysical function diagnosis. In the present study, we developed a case-based interprofessional learning tool for using biophysical information for diagnosis. The study examined the effects of a collaborative exercise workshop for healthcare professional students using the tool. Participants were 234 students from three healthcare professions (medical technology, radiological science, and physical therapy). They completed the Japanese version of the Readiness for Interprofessional Learning Scale before and after the workshops. The workshops incorporated digital materials that allowed students to examine the test results of a virtual patient, answer questions, and discuss their diagnoses and prognoses. For analysis, a two-way analysis of variance was performed on the total score on the Readiness for Interprofessional Learning Scale of the three departments, and the effectiveness of the workshop for the three departments was compared. Statistical analyses showed no interaction between time and department (p = 0.283). After the workshop, students from all three departments showed significant improvements in total scores on the Readiness for Interprofessional Learning Scale (p < 0.01) with medium to large effect sizes (r = 0.33-0.52). In the comparison between departments, there was a significant difference in the awareness levels of only medical technology and radiological science students before the workshop (p = 0.015). This study conducted case-based learning workshops with students from three departments, in which a patient's biophysical information was conveyed between occupational practices. The workshops improved the awareness of interprofessional education in students from all departments and revealed that interprofessional education is important for healthcare professions involved in biophysical function diagnosis.

Long-term follow-up of patients with paroxysmal nocturnal hemoglobinuria treated with eculizumab: post-marketing surveillance in Japan.

All Japanese patients with paroxysmal nocturnal hemoglobinuria (PNH) treated with eculizumab were enrolled in post-marketing surveillance (PMS) between June 2010 and August 2019 to assess the long-term effectiveness and safety of eculizumab. The reduction in intravascular hemolysis, the change in hemoglobin (Hb) level, and the change in renal function were assessed to determine the effectiveness of eculizumab. The types and frequencies of adverse events (AEs) were assessed to determine its safety. A total of 632 patients were enrolled and the median treatment duration was 3.6 years. Treatment with eculizumab significantly reduced lactate dehydrogenase (LDH) levels and significantly increased Hb levels. These changes were maintained for up to 5 years of treatment. An estimated glomerular filtration rate ≥ 60 ml/min/1.73 m2 and higher LDH level at baseline were associated with increases in Hb levels during eculizumab treatment. The overall incidence of any AE was 69.92/100 patient-years. Hemolysis was the most common AE (6.43/100 patient-years). The incidence of infection-related AEs was 20.57/100 patient-years, and included meningococcal infection in three patients (0.12/100 patient-years). This long-term follow-up of patients with PNH demonstrated the sustained effectiveness of eculizumab and supports its well-established safety profile.

The clinical significance of PNH-phenotype cells accounting for < 0.01% of total granulocytes detected by the Clinical and Laboratory Standards Institute methods in patients with bone marrow failure.

Small populations of glycosylphosphatidylinositol-anchored protein-deficient (GPI[-]) cells accounting for up to 0.01% of total granulocytes can be accurately detected by a high-sensitivity flow cytometry (FCM) assay established by the Clinical and Laboratory Standards Institute (CLSI method) and have a prognostic value in bone marrow failure (BMF); however, the significance of GPI(-) granulocytes accounting for 0.001-0.009% of granulocytes remains unclear. To clarify this issue, we examined the peripheral blood of 21 BMF patients in whom minor (around 0.01%) populations of GPI(-) granulocytes had been previously detected by a different high-resolution FCM method (OPTIMA method, which defines ≥ 0.003% GPI(-) granulocytes as an abnormal increase) using both the CLSI and OPTIMA methods simultaneously. These two methods detected an "abnormal increase" in GPI(-) granulocytes in 10 patients (48%) and 17 patients (81%), respectively. CLSI detected 0.002-0.005% (median, 0.004%) GPI(-) granulocytes in 7 patients who were deemed positive for PNH-type cells according to the OPTIMA method, which detected 0.003-0.012% (median 0.006%) GPI(-) granulocytes. The clone sizes of GPI(-) cells detected by each assay were positively correlated (r = 0.994, p < 0.001). Of the seven patients who were judged positive for PNH-type cells by OPTIMA alone, five received immunosuppressive therapy, and all of them achieved a partial or complete response. GPI(-) granulocytes detected in BMF patients by the CLSI method should thus be considered significant, even at percentages of < 0.01%.

The complement C5 inhibitor crovalimab in paroxysmal nocturnal hemoglobinuria.

Complement C5 inhibition is the standard of care (SoC) for patients with paroxysmal nocturnal hemoglobinuria (PNH) with significant clinical symptoms. Constant and complete suppression of the terminal complement pathway and the high serum concentration of C5 pose challenges to drug development that result in IV-only treatment options. Crovalimab, a sequential monoclonal antibody recycling technology antibody was engineered for extended self-administered subcutaneous dosing of small volumes in diseases amenable for C5 inhibition. A 3-part open-label adaptive phase 1/2 trial was conducted to assess safety, pharmacokinetics, pharmacodynamics, and exploratory efficacy in healthy volunteers (part 1), as well as in complement blockade-naive (part 2) and C5 inhibitor-treated (part 3) PNH patients. Twenty-nine patients were included in part 2 (n = 10) and part 3 (n = 19). Crovalimab concentrations exceeded the prespecified 100-µg/mL level and resulted in complete and sustained terminal complement pathway inhibition in treatment-naive and C5 inhibitor-pretreated PNH patients. Hemolytic activity and free C5 levels were suppressed below clinically relevant thresholds (liposome assay <10 U/mL and <50 ng/mL, respectively). Safety was consistent with the known profile of C5 inhibition. As expected, formation of drug-target-drug complexes was observed in all 19 patients switching to crovalimab, manifesting as transient mild or moderate vasculitic skin reactions in 2 of 19 participants. Both events resolved under continued treatment with crovalimab. Subcutaneous crovalimab (680 mg; 4 mL), administered once every 4 weeks, provides complete and sustained terminal complement pathway inhibition in patients with PNH, warranting further clinical development (ClinicalTrials.gov identifier, NCT03157635).

Establishment of a flow cytometry assay for detecting paroxysmal nocturnal hemoglobinuria-type cells specific to patients with bone marrow failure.

Minor populations of glycosylphosphatidylinositol-anchored protein-deficient (GPI[-]) cells in the peripheral blood may have a prognostic value in bone marrow failure (BMF). Our objective is to establish the optimal flow cytometry (FCM) assay that can discriminate GPI(-) populations specific to BMF from those of healthy individuals. To identify a cut-off that discriminates GPI(-) rare cells from GPI(+) cells, we determined a position of the borderline that separates the GPI(-) from GPI(+) cells on a scattergram by testing more than 30 healthy individuals, such that no GPI(-) dot fell into the upper left quadrant where fluorescein-labeled aerolysin (FLAER)-CD11b+ granulocytes and CD55-CD59- glycophorin A+ erythrocytes were positioned. This method allowed us to define ≥ 0.003% CD11b+FLAER- granulocytes and ≥ 0.005% glycophorin A+CD55-CD59- erythrocytes to be specific to BMF patients. Longitudinal cross-validation studies showed minimal (< 0.02%) inter-laboratory differences in the GPI(-) cell percentage. An analysis of 1210 patients with BMF revealed a GPI(-) cell population in 56.3% of patients with aplastic anemia and 18.5% of patients with myelodysplastic syndrome. The GPI(-) granulocyte percentages was 0.003-0.01% in 3.7% of patients. This FCM assay effectively identified an increase in the percentage of GPI(-) rare cells that are specific to BMF patients and allowed different laboratories to accurately detect 0.003-0.01% of pathological GPI(-) cells.

Correction to: Effects of eculizumab treatment on quality of life in patients with paroxysmal nocturnal hemoglobinuria in Japan.

In the original publication of this article, Tables 2, 3 and 4 were published incorrectly. The corrected tables 2, 3 and 4 are given in the following pages.

Effects of eculizumab treatment on quality of life in patients with paroxysmal nocturnal hemoglobinuria in Japan.

In paroxysmal nocturnal hemoglobinuria (PNH), various symptoms due to intravascular hemolysis exert a negative impact on patients' quality of life (QOL). To determine clinical factors related with improvements in QOL in PNH patients treated, we analyzed changes in QOL scales in PNH patients treated with eculizumab based on data collected from post-marketing surveillance in Japan. Summary statistics were obtained using figures from QOL scoring systems and laboratory values, and evaluated by t test. One-year administration of eculizumab improved the most QOL items in comparison with the baseline. In particular, significant improvement of EORTC QLQ-C30 was observed in fatigue, dyspnea, physical function, and global health status. Canonical correlation analysis revealed a high correlation between QOL and laboratory values. Changes in serum lactate dehydrogenase (LDH) and hemoglobin showed strong correlations with QOL improvement. Quality of life improvement was independent of patients' baseline characteristics of co-occurrence of bone marrow failure (BMF), or the degree of LDH. In this analysis, we found that the degree of QOL improvement was independent of the baseline LDH before eculizumab treatment and of co-occurrence of BMF. Paroxysmal nocturnal hemoglobinuria patients who have not received eculizumab treatment due to mild hemolysis may benefit from eculizumab treatment.

Interim analysis of post-marketing surveillance of eculizumab for paroxysmal nocturnal hemoglobinuria in Japan.

Data characterizing the safety and effectiveness of eculizumab in patients with paroxysmal nocturnal hemoglobinuria (PNH) are limited. We describe the safety and effectiveness of eculizumab in PNH patients enrolled in a post-marketing surveillance study. Types and frequencies of observed adverse events were similar to those reported in previous clinical trials and no meningococcal infection was reported. Effectiveness outcomes included the reduction of intravascular hemolysis, the change in hemoglobin (Hb) level, the withdrawal of transfusion and corticosteroids, the change of renal function, and overall survival. The effect of eculizumab on intravascular hemolysis was demonstrated by a reduction in lactate dehydrogenase levels at all measurements after baseline. Significant increases in Hb levels from baseline were also observed after 1 month's treatment with eculizumab (p < 0.01). Of those who were transfusion-dependent at baseline, the median number of transfusions decreased significantly from 18 to 0 unit/year after 1 year of treatment with eculizumab (p < 0.001). An increase in Hb and a high rate of transfusion independence were observed, especially in patients with platelet count ≥150 × 109/L. Approximately 97 % of patients showed maintenance or improvement of renal function. Overall survival rate was about 90 % (median follow-up 1.9 years). These results suggest an acceptable safety profile and favorable prognosis after eculizumab intervention.

Pregnancy outcomes of patients with paroxysmal nocturnal hemoglobinuria treated with eculizumab: a Japanese experience and updated review.

Pregnancy with paroxysmal nocturnal hemoglobinuria (PNH) is associated with significant risk of complications, such as life-threatening thrombosis. Recently, eculizumab has come into clinical use and revolutionized the treatment of PNH. However, clinical information regarding eculizumab use for PNH during pregnancy is limited. The present report describes pregnancies with PNH treated with eculizumab that were registered with the Japan PNH study group and reviews the literature. In case 1, the patient received eculizumab throughout pregnancy and delivered a healthy neonate at term, although breakthrough hemolysis occurred at 20 weeks of gestation. In case 2, the patient discontinued eculizumab before pregnancy and developed preeclampsia at 27 weeks of gestation. She received eculizumab and delivered a preterm, but healthy, neonate by cesarean section. In case 3, the patient received eculizumab from 18 weeks of gestation and delivered a healthy neonate at term without any complications. Reports of 11 pregnant women treated with eculizumab were identified in the literature. Of 14 pregnancies, including our own cases, breakthrough hemolysis and preeclampsia occurred in five and two cases, respectively. There were no thrombotic complications, maternal or neonatal deaths, or fetal structural abnormalities. Thus, eculizumab appears to be safe and effective for managing PNH during pregnancy.

Sodium Bicarbonate Facilitates Hemostasis in the Presence of Cerebrospinal Fluid Through Amplification of Platelet Aggregation.

BACKGROUND: Appropriate hemostasis is essential for clear visualization of the neural structures and cleavage planes. It is also essential for avoiding heat-induced injury, minimizing blood loss, and reducing operative time. OBJECTIVE: To determine the role of cerebrospinal fluid (CSF) in platelet-dependent hemostasis during neurosurgery. METHODS: The amplification of aggregation, activation of integrin αIIbß3, intrinsic and extrinsic coagulation pathways, and activation of signaling cascades in platelets were evaluated. For comparison, various concentrations of a commercially available artificial CSF solution (aCSF), an artificial CSF solution prepared by the authors, and normal saline (NS) were used. Differences between aCSF and NS in obtaining in vivo hemostasis were assessed by measuring the tail vein bleeding time in C57BL/6N mice. RESULTS: Platelet aggregation was directly amplified by the addition of aCSF through increased activation of integrin αIIbß3, phosphatidylserine exposure, and P-selectin expression. However, the prothrombin time and activated partial thromboplastin time were not primarily related to coagulation activity with the addition of aCSF. Activation of Src kinase was related to platelet activation by aCSF. The elimination of sodium bicarbonate from aCSF and the addition of the selective inhibitor of the HCO3/Cl exchanger, 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid disodium salt, significantly inhibited platelet aggregation. The bleeding time in aCSF-treated mice was significantly shorter than that in NS-treated mice. CONCLUSION: Sodium bicarbonate facilitates hemostasis through the amplification of platelet aggregation function. The existence of CSF and irrigation with aCSF provide better conditions for physiological hemostasis and they have the potential of improving hemostasis by bipolar coagulation or with irrigation during neuroendoscopic procedures.

Improvement of Renal Function by Long-Term Sustained Eculizumab Treatment in a Patient with Paroxysmal Nocturnal Hemoglobinuria.

Chronic kidney disease (CKD) is one of the major manifestations of paroxysmal nocturnal hemoglobinuria (PNH). CKD in PNH is induced mainly by intravascular hemolysis of PNH-affected red blood cells (RBC) missing the glycosylphosphatidylinositol-anchored proteins with complement-regulatory activities, CD55 and CD59. CKD develops by heme absorption in the proximal tubules resulting in the interstitial deposition of iron in the kidneys. We administered eculizumab to a patient with PNH, who was one of 29 patients enrolled in the AEGIS clinical trial, an open-label study of eculizumab in Japan. The patient was complicated by stage 3 CKD with impaired estimated glomerular filtration rate (eGFR), at grade G3b, and had obvious proteinuria (2-3+, 1-2 g/day). In a two-year extension to the 12-week AEGIS study, eGFR improved significantly, and the eGFR has since been maintained at grade G2 without proteinuria by sustained eculizumab treatment (>6 years). Renal function improved and maintained by long-term sustained eculizumab treatment, presumably by clearance of iron from the kidney as well as inhibition of the production of anaphylatoxin C5a, even in advanced stages of CKD, is one of the benefits of eculizumab treatment in PNH.

Long-term efficacy and safety of eculizumab in Japanese patients with PNH: AEGIS trial.

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, progressive hematopoietic stem cell disorder characterized by chronic complement-mediated hemolysis leading to life-threatening complications and early mortality. Eculizumab, a humanized anti-C5 monoclonal antibody, inhibits terminal complement activation, reduces hemolysis, decreases the risk of thrombosis, and improves renal function and quality of life in PNH patients. The long-term efficacy and safety of eculizumab in Japanese patients were assessed in a 2-year extension to a 12-week, open-label study (AEGIS). Eculizumab treatment led to an immediate and sustained reduction in intravascular hemolysis (P < 0.001) and red blood cell transfusions (P = 0.0016) compared with baseline levels. There were no reports of thromboembolism during eculizumab treatment. The majority of patients had stable (56 %) or improved (41 %) renal function and an improved quality of life (P = 0.015), with sustained reductions in fatigue and dyspnea. Eculizumab was well tolerated; no deaths or serious hemolytic events were reported, and the rate of infections declined over time. There were no significant differences in the response to eculizumab in patients with or without bone marrow dysfunction. These results demonstrate that eculizumab is an effective, well-tolerated long-term treatment for Japanese PNH patients and leads to continued amelioration of some hemolytic complications.

Perisurgical induction of eculizumab in a patient with paroxysmal nocturnal hemoglobinuria: its inhibition of surgery-triggered hemolysis and the consequence of subsequent discontinuation.

Paroxysmal nocturnal hemoglobinuria (PNH) is characterized by complement (C')-induced lysis of PNH red blood cells (RBCs), which are deficient in the expression of CD55 and CD59. Surgery is one of the major clinical situations that trigger hemolytic attack and thrombosis in PNH. We describe here a case of 64-year-old man with classic PNH complicated by early-stage gastric cancer requiring distal gastrectomy under general anesthesia. We administered humanized monoclonal anti-C5 antibody (eculizumab; Soliris) for a limited period (600 mg, once a week × four times) perisurgically. Eculizumab effectively inhibited the C' system and the patient underwent a curative distal gastrectomy without significant surgery-triggered hemolytic attack. Although discontinuation of eculizumab induced mild hemolysis 2 weeks after the last administration, it was treated conservatively without thrombotic complication. Limited-term induction of eculizumab could be an option for PNH patients with transient and anticipated high risks, with careful preparation for the discontinuation-related risks afterwards.

Oral eltrombopag for up to three years is safe and well-tolerated in Japanese patients with previously treated chronic immune thrombocytopenia: an open-label, extension study.

Eltrombopag is an oral, nonpeptide, thrombopoietin receptor agonist approved for treatment of chronic immune thrombocytopenia (ITP). The safety, tolerability, and efficacy of eltrombopag for up to 3 years were evaluated in 19 Japanese patients with chronic ITP who had completed a prior 6-month study. Patients received eltrombopag once daily at the last dosage received in the prior study (12.5, 25, or 50 mg). Dose adjustments and treatment interruptions were permitted to maintain platelet counts of 50,000-200,000/µL. Primary evaluations were safety and tolerability of long-term eltrombopag treatment. The median duration of exposure was 27.5 months (range, 9.9-32.3). Adverse events were similar to those reported with short-term use of eltrombopag, and none led to treatment discontinuation. Nine serious adverse events were reported. Median platelet counts began to increase after 1 week of treatment and remained above 50,000/µL for most assessments. Bleeding episodes decreased from 63 % at baseline to 21 % after 2 weeks of treatment and remained below baseline for all assessments. Of 15 patients receiving concomitant baseline ITP medications, 10 permanently discontinued or achieved a sustained reduction of at least one treatment without requiring rescue treatment. Long-term treatment with eltrombopag was safe, well tolerated, and effective in Japanese patients with chronic ITP.

An open-label extension study evaluating the safety and efficacy of romiplostim for up to 3.5 years in thrombocytopenic Japanese patients with immune thrombocytopenic purpura (ITP).

Long-term use of the thrombopoietin mimetic romiplostim was examined in Japanese patients with chronic immune thrombocytopenic purpura (ITP) in this open-label extension. The starting dose of romiplostim was the previous trial dose or 3 µg/kg/week, which was titrated up to 10 µg/kg/week to maintain platelet counts between 50 and 200 × 10(9)/L. As of April 2010, 44 patients had enrolled; 71 % women, median age 55.5 years, with five patients discontinuing romiplostim due to patient request (2), administrative decision (2), or not achieving study-defined platelet response (1). Median treatment duration was 100 weeks; median average weekly dose was 3.8 µg/kg. Twenty-eight patients (64 %) self-injected romiplostim. The most frequent adverse events were nasopharyngitis and headache. Nine patients (20 %) had a total of 14 serious adverse events (0.31/100 patient-weeks); of these, only oral hemorrhage was considered treatment related. Fifty hemorrhagic adverse events were reported in 20 patients (46 %) (1.12/100 patient-weeks). Ninety-six percent of patients had a platelet response (doubling of baseline platelet count and platelet count ≥ 50 × 10(9)/L). Of the 25 patients receiving concurrent ITP therapy at baseline, all reduced or discontinued the therapy. Eight patients (18 %) received rescue medications. Administration of up to 3.5 years of romiplostim increased platelet counts and was well tolerated in Japanese patients with chronic ITP.

c-Maf plays a crucial role for the definitive erythropoiesis that accompanies erythroblastic island formation in the fetal liver.

c-Maf is one of the large Maf (musculoaponeurotic fibrosarcoma) transcription factors that belong to the activated protein-1 super family of basic leucine zipper proteins. Despite its overexpression in hematologic malignancies, the physiologic roles c-Maf plays in normal hematopoiesis have been largely unexplored. On a C57BL/6J background, c-Maf(-/-) embryos succumbed from severe erythropenia between embryonic day (E) 15 and E18. Flow cytometric analysis of fetal liver cells showed that the mature erythroid compartments were significantly reduced in c-Maf(-/-) embryos compared with c-Maf(+/+) littermates. Interestingly, the CFU assay indicated there was no significant difference between c-Maf(+/+) and c-Maf(-/-) fetal liver cells in erythroid colony counts. This result indicated that impaired definitive erythropoiesis in c-Maf(-/-) embryos is because of a non-cell-autonomous effect, suggesting a defective erythropoietic microenvironment in the fetal liver. As expected, the number of erythroblasts surrounding the macrophages in erythroblastic islands was significantly reduced in c-Maf(-/-) embryos. Moreover, decreased expression of VCAM-1 was observed in c-Maf(-/-) fetal liver macrophages. In conclusion, these results strongly suggest that c-Maf is crucial for definitive erythropoiesis in fetal liver, playing an important role in macrophages that constitute erythroblastic islands.

Procoagulant properties of microparticles released from red blood cells in paroxysmal nocturnal haemoglobinuria.

Thrombosis in paroxysmal nocturnal haemoglobinuria (PNH) has been suggested to be due to several pathophysiological states: a suppressed fibrinolytic system, increased leucocyte-derived tissue factor, complement (C')-mediated damage to platelets and endothelia, or increased platelet- and endothelium-derived microparticles (MPs). Because haemolytic attack is often accompanied by thrombosis in PNH, we studied the role of C'-induced release of MPs in the thrombogenesis of PNH. C' activation induced procoagulant alteration in PNH red blood cells (RBC), when assessed by thrombin generation in the presence of C'-activated PNH RBC, which was abolished by their subsequent treatment with annexin V. Significant amounts of procoagulant MPs, measured by phosphatidylserine-binding prothrombinase activity, were released from PNH RBC in association with the formation of C5b-9, but not significantly before C5b-8. Generation of procoagulant, annexin V-binding, MPs from C'-activated RBC was studied also by flow cytometry. While phorbol 12-myristate 13-acetate, an activator of protein kinase C (PKC), induced the release of MPs from normal RBC as well as PNH RBC, C'-induced release of MPs from PNH RBC was Ca(2+) -independent and not associated with the activation of PKC, calpain or caspase. Procoagulant properties of MPs released from PNH RBC could contribute to the thrombogenesis of PNH.

Safety and efficacy of the terminal complement inhibitor eculizumab in Japanese patients with paroxysmal nocturnal hemoglobinuria: the AEGIS clinical trial.

Paroxysmal nocturnal hemoglobinuria (PNH) is a progressive and life-threatening disease characterized by complement-mediated chronic hemolysis, resulting in serious life-threatening complications and early mortality. Eculizumab, a humanized anti-C5 monoclonal antibody that inhibits terminal complement activation, has been shown to reduce hemolysis in PNH patients. The pivotal open-label, 12-week phase II registration study (AEGIS) was designed to evaluate the efficacy and safety of eculizumab in Japanese patients with PNH. This trial achieved its primary endpoint of reducing intravascular hemolysis with high statistical significance. Twenty-seven of the 29 patients responded to eculizumab treatment, resulting in an 87% reduction in hemolysis (P < 0.0001) and subsequent improvement in anemia (P = 0.0003) despite reduction in transfusion requirements (P = 0.006). Fatigue and dyspnea significantly improved within 1-2 weeks of eculizumab treatment and the improvement was independent of changes in hemoglobin. Chronic kidney disease (CKD) was common (66%) and eculizumab treatment improved CKD in 41% of patients at 12 weeks (P < 0.001). Elevated thrombotic risk was evident in Japanese PNH patients and eculizumab treatment normalized D: -dimer levels in 45% of patients with elevated D: -dimers at baseline (P < 0.001). The AEGIS results demonstrate that eculizumab is effective, safe and well tolerated in Japanese patients with PNH.