Complication Of Paroxysmal Nocturnal Hemoglobinuria Research Articles

Thromboembolic events in patients with paroxysmal nocturnal hemoglobinuria (PNH): Real world data of a Greek nationwide multicenter retrospective study.

Thrombosis is the most common and a life-threatening complication in patients with Paroxysmal Nocturnal Hemoglobinuria. One-third of patients with PNH experience at least one thromboembolic event during the course of the disease, with thrombosis being the most common cause of death in these patients. The mechanism of thrombosis in PNH is complex and continues to be of great research interest. Since the introduction of C5 complement inhibitors in the treatment of PNH, the incidence of thromboembolic events has decreased substantially. We retrospectively analyzed data concerning the thrombotic episodes of 41 patients with PNH from 14 different national hematology centers in Greece. Sixteen patients (39%) experienced at least one episode of thrombosis, including, seven (43.8%) at diagnosis, seven (43.8%) during the course of the disease and two (12.5%) patients prior to PNH diagnosis. Nearly half of these individuals (n=7, 43.8%) had multiple episodes of thrombosis during the course of their disease. The most common sites of thrombosis were intra-abdominal veins. Three out of 26 patients developed thrombosis while on eculizumab. In none of the 16 patients, the thrombotic event was fatal. Our findings, despite the small number of patients, confirmed that thrombosis continues to be a significant complication of PNH affecting more than one third of the patients.

P839: PATIENTS WITH PAROXYSMAL NOCTURNAL HEMOGLOBINURIA TREATED WITH PEGCETACOPLAN SHOW IMPROVEMENTS IN D-DIMER NORMALIZATION AND DECREASE IN INCIDENCE OF THROMBOSIS

Background: Thrombosis is the main life-threatening complication of paroxysmal nocturnal hemoglobinuria (PNH), a rare acquired hematologic disease. Pegcetacoplan (PEG) is a C3 complement-inhibitor approved by the FDA/EMA for treatment of adults with PNH. Aims: This post hoc analysis examined incidence of thrombosis, anti-thrombotic therapy (ATT), and D-dimer normalization in adult patients with PNH treated with PEG in the Phase 3 PEGASUS (NCT03500549) and PRINCE (NCT04085601) studies. Methods: PEGASUS enrolled adult patients with PNH with prior suboptimal response to eculizumab (ECU) despite stable ECU treatment (≥3 months) and hemoglobin (Hb) levels <10.5 g/dL at screening. For the randomized controlled period (RCP), patients were randomized 1:1 to ECU (n=39) or PEG (n=41; 1080 mg subcutaneously [sc] 2x weekly) for 16 weeks. Thereafter, ECU patients were switched to PEG monotherapy and PEG RCP patients remained on PEG during the open-label period (OLP, n=77) through Week 48. PRINCE compared PEG treatment (n=35; 1080 mg sc 2x weekly) in complement-inhibitor-naïve patients to patients receiving control treatment (CTRL; excluding complement-inhibitors i.e., ECU/ravulizumab; n=18). CTRL patients had the option to escape to the PEG group if Hb levels decreased ≥2 g/dL from baseline (n=11). Safety analyses in all trials included monitoring of thrombotic events. D-dimer normalization, defined as D-dimer level less than the upper limit of normal (0.5 µg/mL) was examined at baseline, Week 8, and the end of the study period (PEGASUS: 16 weeks [RCP] and 48 weeks [OLP], PRINCE: 26 weeks). Results: Prior to study entry, 31% (n=25) of PEGASUS patients (6 of these while on ECU therapy) and 9% (n=5) of PRINCE patients experienced at least one type of thrombosis. During the PEGASUS OLP, 2 of 77 patients experienced a thrombotic event, one in the setting of non-Hodgkin’s lymphoma and one during sepsis; neither event was deemed related to PEG. No patients in the PEGASUS RCP or PRINCE trial experienced a thrombotic event. Pooled analysis of completed clinical trials of PEG including PEGASUS and PRINCE indicated there were 2 cases of thrombosis in 164 patients comprising 130 patient-years (1.54 events per 100 patient-years), compared to 1.77 events per 100 patient-years for patients on ECU treatment before entry into PEGASUS. In PEGASUS, 34% (n=27) of patients were on ATT prior to study entry. During the PEGASUS RCP, concomitant ATT was observed in 37% (PEG, n=15) and 33% (ECU, n=13) of patients, and during the PEGASUS-OLP in 23% (n=18) of patients (PEG monotherapy). In PRINCE, concomitant ATT decreased from 21% (n=11) prior to the study to 7% (PEG, n=3) and 0% (CTRL, n=0) during the study. In PEGASUS, D-dimer normalization in the PEG arm increased from 73% (baseline, n=30) to 89% (Week 8, n=33) and was largely sustained at Week 16 and Week 48 (Table 1). D-dimer normalization in the ECU arm increased once ECU patients switched to PEG monotherapy, from 76% (Week 16, n=29) to 89% (Week 48, n=17) (Table 1). In PRINCE, D-dimer normalization in the PEG arm increased from 51% (baseline, n=18) to 67% (Week 8, n=18) and increased further to 68% (n=19) at Week 26 (Table 1). Image:Summary/Conclusion: Overall, these results demonstrate that PEG treatment can increase D-dimer normalization and reduces incidence of thrombotic events in patients with PNH who are complement-inhibitor naïve or remained anemic after ECU treatment, suggesting that PEG treatment is as effective as ECU in these outcomes.

Detection of paroxysmal nocturnal haemoglobinuria clones in cases of deep vein thrombosis in a tertiary care centre, western Rajasthan.

Paroxysmal nocturnal haemoglobinuria is a rare acquired disease characterized by bone marrow failure, intravascular haemolysis and thrombophilia. Thrombosis is the deadliest complication of paroxysmal nocturnal haemoglobinuria (PNH). The present study was conducted to study the prevalence of PNH in cases of deep vein thrombosis (DVT) which was previously undocumented from western Rajasthan. In the present cross-sectional study, 61 adult patients with DVT were tested using flow cytometry to detect PNH clones. Blood samples were processed using fluorescein-labelled proaerolysin, CD14, CD24, CD33 and CD45 panels for granulocytes and monocytes and CD59 and CD235a panel for red blood cells. Three cases (4.92%) having large clones on monocytes as well as granulocytes, which fulfilled the diagnostic criteria of PNH were detected. Further, three cases (4.92%) showed small clones on both granulocytes and monocytes. Nine (15%) cases showed small clones only on granulocytes, and 11 (18%) cases showed small clones only on monocytes. The results of the present study suggest that a higher proportion of patients had PNH in western Rajasthan compared to previously reported studies from elsewhere. It is suggested that PNH testing should be added to the procoagulant work-up panel in institutions of this region where it is not routinely done. This provides an otherwise missed opportunity to diagnose this disorder. Eculizumab may be employed, which is effective in reducing thrombophilic events in cases of PNH.

Popliteal artery thrombosis as a rare complication of paroxysmal nocturnal hemoglobinuria (PNH): A case report.

Introduction and importancePopliteal artery thrombosis a rare but life-threatening complication of Paroxysmal Nocturnal Hemoglobinuria caused due to hemolysis. Complications of further thrombotic event are common after initial management.Case presentationA 38 years old male, known case of PNH for 2 years, presented with the history of loss of pain sensation, coldness and loss of movement in left lower leg for 5 days and history of multiple blood transfusion. The patient underwent knee amputation because of possible complication of PNH.Clinical discussionIntermittent claudication along with paresthesia, lower extremity weakness, stiffness, and cool extremities are seen in patients of Peripheral Artery Disease. Ultrasound color duplex is a sensitive and specific examination for peripheral flow while gold standard techniques like MRI and CT angiogram to detect and diagnose arterial lesions.ConclusionThe risk of thrombo-embolism in a patient of PNH should be considered by a treating doctor while early imaging and management should be done to reduce the complications and risk of amputation.

Interim Analysis of Safety Outcomes during Treatment with Eculizumab: Results from the International Paroxysmal Nocturnal Hemoglobinuria Registry

Background/Objective: Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, progressive, life-threatening disorder characterized by complement-mediated intravascular hemolysis and a prothrombotic state. Eculizumab, a terminal complement inhibitor inhibits intravascular hemolysis and thrombosis, and decreases mortality risk in patients with PNH. More information is needed regarding outcomes associated with long-term treatment. The International PNH Registry (NCT01374360) is an ongoing prospective, multinational, observational study established to record the natural history of patients with PNH and collect data on long-term efficacy and safety of eculizumab treatment. The objective of this analysis was to assess safety outcomes in patients in the PNH Registry by treatment status with eculizumab.Methods: Patients enrolled in the Registry as of July 5, 2016, were eligible for the current analyses. Patient-time was classified as ever-treated with eculizumab or untreated with eculizumab. The patient-time in the eculizumab-treated group was assessed starting at initiation of eculizumab and followed through last Registry follow-up. The untreated-with-eculizumab group included those who never received eculizumab treatment prior to enrollment in the Registry; these patients contributed untreated patient-time starting at enrollment and followed through last untreated follow-up (initiation of eculizumab or last Registry follow-up). For the eculizumab-treated group, baseline was defined as the date of eculizumab initiation; for the untreated-with-eculizumab group, baseline was defined as the date of Registry enrollment. Patients who were enrolled while untreated and later initiated treatment with eculizumab contributed patient-time to both groups. Incidence rates were calculated for outcomes of interest reported on case report forms, except for subtypes of infections and malignancies where write-in text describing the infection or malignancy was coded by the authors to be one of the subtypes of interest.Results: Of the 4448 patients enrolled in the Registry, 4013 had non-missing data on demographics, enrollment date, and eculizumab status and were included in the current analyses (eculizumab-treated, n=1587; untreated-with-eculizumab at enrollment, n=3058); 632 patients contributed patient-time to both groups. The mean (standard deviation) follow-up time for the eculizumab-treated and untreated-with-eculizumab groups was 50.0 (30.9) and 32.1 (25.0) months, respectively. Mean age at baseline was similar in the eculizumab-treated and untreated-with-eculizumab groups (43.4 vs 44.8 years, respectively). At baseline, 91% in the eculizumab-treated group had LDH ≥1.5x upper limit of normal prior to treatment, compared with 50% of untreated-with-eculizumab patients. More patients in the eculizumab-treated group had a history of thrombotic events (TE; 23% vs 9%) or other major adverse vascular events (MAVE; 12% vs 9%) compared with untreated-with-eculizumab patients. Rates of TE, other MAVE, solid tumors, impaired renal function (IRF), impaired hepatic function (IHF), pulmonary hypertension, and mortality were substantially lower in the eculizumab-treated group during follow-up compared with the untreated-with-eculizumab group, while estimated rates of overall infections and hematologic malignancies were similar in the 2 treatment groups (Table). In the subset of 632 patients enrolled while untreated with eculizumab but later started eculizumab after enrollment, rates of TE, other MAVE, solid tumors, IRF, IHF, and pulmonary hypertension were lower following initiation of eculizumab. Of the 18 cases of Neisseria infection in 16 patients in the eculizumab-treated group (Table), 13 were confirmed meningococcal infections (12 resolved, 1 ongoing at time of data cut-off). One patient in the untreated-with-eculizumab group had a Neisseria infection. No fatal outcomes due to meningococcal infection or other encapsulated organisms were reported in any group in this analysis.Conclusions: With 6399 patient-years of eculizumab exposure in the largest global Registry of patients with PNH, eculizumab appears to be safe with no new safety findings identified. Rates of complications of PNH are lower in patients treated with eculizumab compared with those who are untreated. The benefit-risk ratio for patients treated with eculizumab remains favorable. [Display omitted] DisclosuresHill:Alexion Pharmaceuticals, Inc.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Roeth:Alexion Pharmaceuticals, Inc.: Consultancy, Honoraria; Roche: Consultancy, Honoraria. Socié:Alexion Pharmaceuticals, Inc.: Consultancy. Caby-Tosi:Alexion Europe SAS: Employment, Equity Ownership. Wilson:Alexion Pharmaceuticals, Inc.: Employment, Equity Ownership. Gustovic:Alexion Pharma GmbH: Employment, Equity Ownership. Bedrosian:Alexion Pharmaceuticals, Inc.: Employment, Equity Ownership. Brodsky:Alexion Pharmaceuticals, Inc.: Membership on an entity's Board of Directors or advisory committees, Other: Grant Funding.

Improving Anemia in Patients with Paroxysmal Nocturnal Hemoglobinuria

The major clinical complications of paroxysmal nocturnal hemoglobinuria (PNH) include a pronounced symptom burden (fatigue, abdominal pain, chest

Thrombotic Events with Neisseria Meningitidis Vaccination in Patients with Paroxysmal Nocturnal Hemoglobinuria, UK Experience

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare hemolytic and thrombotic condition. Patients can experience severe anemia due to intravascular hemolysis, thrombotic events, renal impairment and pulmonary hypertension. Symptomatic patients are treated with complement inhibitors either in clinical trials or with eculizumab the only licensed treatment in the UK. Due to the mechanism of action of eculizumab, it increases susceptibility to Neisseria infection, including Neisseria meningitidis. To reduce this risk of infection, worldwide practice is for patients to be vaccinated at least 2 weeks prior to receiving eculizumab (serogroups A, C, Y, W 135 and B). It was noted within the PNH National Service at Leeds (UK) that a small number of patients deteriorated with enhanced intravascular hemolysis and thrombosis during the period between vaccination and eculizumab, leading to a review of practice. We report five of 121 patients with events in the intervening 2 weeks between vaccination and commencement of eculizumab from 2002-2012:A 44 year female presented with hemolysis and hemoglobinuria, with a granulocyte PNH clone of 99.4%. She was transfusion dependent and on anticoagulation. She consented to the PNH pilot eculizumab study, undergoing meningococcal vaccination as per protocol. Twenty two days later, she suffered an ischemic stroke with left hemiplegia and permanent weakness, resulting in exclusion from the study. Two years later she received eculizumab in the TRIUMPH study.A 37 year male presented with hemoglobinuria and fatigue with a granulocyte PNH clone of 99.58%. He had significant hemolysis, managed initially with warfarin and blood transfusions. He consented to start eculizumab and received meningococcal vaccination. 4 days later he presented with a symptomatic right hepatic vein thrombosis, promptly commenced eculizumab.A 29 year male, with abdominal pain and hemoglobinuria for 3 years developed a stroke and portal vein thrombosis leading to a diagnosis of PNH, with a granulocyte PNH clone of 84.99%. He commenced anticoagulation. Four months after the stroke he received meningococcal vaccination in preparation for scheduled commencement with eculizumab. He experienced a left central retinal vein thrombosis 15 days after its administration prior to starting eculizumab.A 47 year old male, was diagnosed with haemolytic PNH but only had mild symptoms and anaemia. Twenty four years later, he developed increasing hemolysis and symptoms; granulocyte PNH clone of 96.45%. Eculizumab was planned and he received meningococcal vaccination, but presented ten days later with acute renal failure secondary to massive intravascular haemolysis, necessitating emergency eculizumab therapy.A 35 year female, with a granulocyte PNH clone of 99.87%. Although she had active intravascular hemolysis, eculizumab was declined, and anticoagulation commenced. Four years later she consented to start eculizumab, receiving meningococcal vaccination. She was admitted 24 hours later with a stroke and commenced eculizumab the same day, but has persistent neurological impairment to date. See Table 1 Discussion: The close time proximity of these serious events to the patients' vaccinations raised concern that the complement system was being activated by administration of the vaccine, precipitating complications of PNH. It is also concerning that 4 of the 5 patients experienced thrombotic events despite therapeutic anticoagulation, confirming that anticoagulation only partially mitigates the risk of thrombosis in patients with PNH. The decision was taken to administer the vaccination immediately after the first dose of eculizumab, with therapeutic doses of antibiotic (ciprofloxacin 500mg bd) for the first 14 days post vaccination, followed by long term meningococcal prophylaxis (penicillin V or erythromycin 500mg bd) whilst receiving a complement inhibitor. Since this change in practice in 2012 we have commenced eculizumab therapy in 211 patients with no similar complications as described. Thus the change in practice appears to reduce the occurrence of these severe complications associated with vaccinations prior to initiating anti-complement therapy. Whilst it is possible these events could have been caused by the underlying condition of PNH, we would advise colleagues to also adopt a change in practice to reduce potentially significant complications. Disclosures Arnold: Alexion Pharmaceuticals: Honoraria. Kelly:Alexion: Honoraria. Munir:F. Hoffmann-La Roche: Consultancy, Other: Medical writing support, furnished by Scott Battle, PhD, of Health Interactions, was funded by F. Hoffmann-La Roche Ltd, Basel, Switzerland; Alexion: Honoraria. Pike:Apellis: Research Funding. Riley:Alexion: Honoraria. Griffin:Alexion Pharmaceuticals: Honoraria, Other: Conference Support; Biocryst: Membership on an entity's Board of Directors or advisory committees. Hillmen:Acerta: Other: Financial or material support; Roche: Consultancy, Other: Financial or material support, Research Funding, Speakers Bureau; AbbVie: Consultancy, Other: Financial or material support, Research Funding, Speakers Bureau; Pharmacyclics: Other: Financial or material support, Research Funding; Janssen: Consultancy, Other: Financial or material support, Research Funding, Speakers Bureau; AstraZeneca: Consultancy, Speakers Bureau; Apellis: Consultancy, Research Funding, Speakers Bureau; Alexion: Consultancy, Research Funding, Speakers Bureau; Gilead: Other: Financial or material support, Research Funding.

Blood Cell Disorders and the Nervous System.

This article discusses the epidemiology, diagnosis, treatment, and prevention of neurologic complications of common and rare blood cell disorders. A growing number of preventive treatment options are available for stroke in sickle cell disease. Paroxysmal nocturnal hemoglobinuria and immune thrombocytopenia can lead to stroke. Thrombotic thrombocytopenic purpura frequently causes neurologic symptoms and should be considered in the differential diagnosis of a patient with neurologic symptoms, thrombocytopenia, and hemolytic anemia. Polycythemia vera and essential thrombocythemia are rare causes of stroke. This article discusses sickle cell disease and the most recent advances in stroke preventive therapy as well as neurologic complications of paroxysmal nocturnal hemoglobinuria, immune thrombocytopenia, thrombotic thrombocytopenic purpura, polycythemia vera, and essential thrombocythemia.

Gene mutations associated with thrombosis detected by whole-exome sequencing in paroxysmal nocturnal hemoglobinuria.

Thrombosis is a most common and lethal complication of paroxysmal nocturnal hemoglobinuria (PNH), which is a complex progression and its mechanism remains unclear. We tried to explore the possible genetic background of thrombosis in PNH patients and provide potential gene mutations associated with thrombosis in PNH patients. The CD59- cells of 7 PNH and 6 PNH- aplastic anemia (AA) patients were sorted by flow cytometry and sequenced by whole-exome sequencing (WES). The sequencing results and target mutation genes were analyzed and screened, respectively, and Kyoto Encyclopedia of Genes and Genomes (KEGG) signal pathway enrichment analysis was carried out. Finally, the expression of target genes was detected in 22 PNH (including seven cases with thrombus) and 20 normal controls, and the correlation between the expression of mRNA and the clinical thrombus-related indexes was analyzed. The mutation genes screened from 4 PNH with thrombus were BMPR2, F8, ITGA2B, THBD, and THBS1. The pathways enriched by these genes included Notch, Wnt, and arachidonic acid metabolism signaling pathways, which may be related to the pathogenesis of thrombosis in PNH. The BMPR2, THBD, and THBS1 gene expression was significantly different between PNH with and without thrombus group, and the THBS1 gene expression was positively correlated with D-Dimer and su-PAR levels. Genetic defects have a non-negligible effect on the incidence of thrombosis, and therefore, gene mutations maybe a genetic risk factor in PNH, which increase the incidence of thrombosis.

Analysis of Platelets By Flow Cytometry in Patients with Paroxysmal Nocturnal Hemoglobinuria (PNH)

Paroxysmal Nocturnal Hemoglobinuria (PNH) is characterized by a clonal population of hematopoietic stem cells with an acquired somatic mutation in the PIG-A gene, giving rise to populations of circulating mature cells that are unable to synthesize glycosylphosphatidylinositol (GPI). The disease is most readily diagnosed by flow cytometry analysis of red blood cells, using antibodies specific for the GPI-linked protein CD59, or analysis of granulocytes, using antibodies specific for the GPI-linked protein CD24, along with the FLAER reagent, a fluorescent protein that binds to the GPI structure and which is detected only on the surface of GPI (+) cells. However, other mature blood lineages can be derived from the PNH clone. Notably, thrombosis is a major life threatening complication of PNH and may be triggered by complement activation on platelets that belong to the GPI-negative stem cell clone. The PNH clone size generally predicts thrombosis, but sometimes the proportion of PNH red cells and granulocytes are highly discordant, in which case there might be a role for the determination of the proportion of PNH platelets. Historically, flow cytometry analysis of platelets in patients with PNH has been technically difficult. Here is described a method to do this that avoids technical challenges by using aspirin and sepharose gel filtration of platelets to prevent their activation as well as simultaneous determination of CD59 expression and uptake of the FLAER reagent. Red cells were analyzed based on CD59 expression and granulocytes based on CD24 and FLAER. We analyzed blood samples from 48 patients with PNH and or AA/PNH who provided informed consent, 16 of whom had a prior history of thrombosis. To separate platelet rich plasma (PRP), whole blood collected in EDTA tubes was centrifuged at 200g for 7 minutes at room temperature with the brake turned off. After this step, there was no further centrifugation or vortexing of the platelets. A solution of aspirin was made up immediately prior to use and was added to the PRP at a final concentration of 0.5mMolar. Aspirinated PRP was then loaded on top of a sepharose-2B column using Tyrode's buffer. The platelet-rich turbid drops were collected, to isolate platelets from red cells and coagulation proteins. 50 ul of platelet rich buffer was then incubated with FLAER-Alexa-488 (Pinewood, 1:20 dilution) and CD59-PE (Serotec, 1:10 dilution) in the dark for 30' at room temperature. To prevent doublet events from confounding the analysis, the platelet suspension was diluted 1:200 in Hanks with 0.1% BSA. The sample was passed through a 35 uM Falcon cell strainer, and platelets were identified by forward/side scatter acquired on a log-log scale on a BD Facscan. The median proportion of PNH red cells, granulocytes and platelets was 24%, 86%, 76% respectively in the group without a history of thrombosis and 23% ,82%, and 65% in the group with a history of thrombosis. The proportion of PNH platelets was highly correlated with the proportion of PNH granulocytes (r=0.84). In two patients with almost undetectable PNH red cells and over 90% PNH granulocytes, the proportion of PNH platelets was over 90%; both were on prophylaxis and neither had thrombosis. It is predicted that this technique may be useful for determining thrombosis risk, particularly when the results from the analysis of rbc's and granulocytes are discordant. DisclosuresNo relevant conflicts of interest to declare.

Worsening Hepatic Function in Paroxysmal Nocturnal Hemoglobinuria (PNH) Leading to Hemolysis, Gallstones, and Progressive Hepatic Fibrosis

PNH is a rare type of acquired intravascular hemolysis with a limited number of cases reported in the literature. The clinical course is unpredictable and can vary from severe hemolytic anemia, characterized by episodes of hemoglobinuria and life-threatening venous thrombosis, to asymptomatic periods. One serious complication of PNH is progressive hepatic dysfunction. We present the case of a 62-year-old man with a history of PNH controlled with eciluzimab and aplastic anemia who presented with abdominal pain, jaundice, and dark urine. Laboratory studies revealed elevated aminotransferases and indirect hyperbilirubinemia. Abdominal ultrasound demonstrated patent hepatic vasculature and gallbladder sludge without evidence of cholecystitis. MRCP showed no evidence of choledocholithiasis. After improvement in symptoms, the patient again developed frequent and severe episodes of abdominal pain. Laparoscopic cholecystectomy with intraoperative cholangiography demonstrated filling defects within the CBD. Sludge and multiple dark pigmented stones were found in the resection specimen. Liver biopsy revealed subcapsular portal tract hemosiderosis with fibrosis without mass or hepatocellular carcinoma. The patient underwent ERCP and sphincterotomy with removal of small pigment stones from the CBD. The patient's condition improved and he is currently being evaluated for treatment options to decrease risk of progression to cirrhosis. This case demonstrates the natural history of PNH with cholestatic liver disease and pigment stones. Moreover, this patient had evidence of hepatocellular injury on laboratory data with liver biopsy revealing fibrosis. Hepatic vein thrombosis is the most common cause of liver failure in patients with PNH - interestingly, this was not present, and it is ongoing hemolysis and hemosiderosis leading to fibrosis which is the primary etiology of his hepatic dysfunction. Despite progress in the understanding of the disorder, treatment options are largely supportive other than bone marrow transplantation, which carries substantial morbidity and mortality. Given the limited therapeutic options, it is interesting to postulate whether our patient would benefit from trials of antioxidant medications or antifibrotic therapies that may retard progression of liver fibrosis. In conclusion, we present an unusual case of PNH presenting as cholestasis, gallstones and CBD stones, with ongoing hemolysis leading to hepatic fibrosis.Figure 1Figure 1

The dysfunction of platelets in paroxysmal nocturnal hemoglobinuria

IntroductionThrombosis is a dangerous complication of paroxysmal nocturnal hemoglobinuria (PNH) and has a high mortality rate. However, the mechanism underlying the development of thrombosis in PNH remains unclear. To explore this, platelet function and serum complement activity were investigated in 14 patients with classical PNH, 11 with PNH aplastic anemia (AA) and 30 healthy controls. Material and methodsSerum concentrations of the terminal complement complex (sC5b-9) were determined by enzyme-linked immunofluorescence assay (ELISA), and the levels of C5b-9, CD61 and CD62p on platelet membranes were determined by flow cytometry. Clinical parameters were assessed, including D-dimer and platelet aggregation induced by adenosine diphosphate (ADP) and arachidonic acid (ARA). ResultsSerum sC5b-9 concentrations were significantly lower in the PNH/PNH-AA than in the control group (P<0.01). C5b-9 deposition was significantly higher on CD59− platelets than on CD59+ platelets in PNH/PNH-AA patients and healthy controls (P<0.01 for each). D-dimer concentration was significantly higher in PNH/PNH-AA patients – especially those with lactate dehydrogenase (LDH) concentrations>1000U/L – than in controls (P<0.05). CD61 (P<0.05) expression was lower on CD59+ platelets in PNH than in controls and CD5− platelets in PNH. Expression of CD62p (P<0.01) was lower on CD59− and CD59+ platelets (P<0.01) in PNH cases than in controls. Platelet aggregation stimulated by the agonists ADP and ARA in the PNH/PNH-AA patients was significantly lower than that in controls (P<0.05). ConclusionsThe adhesion and aggregation of platelets, especially of CD59+ platelets, were compensatively decreased in PNH/PNH-AA patients without active thrombosis.

Paroxysmal Nocturnal Hemoglobinuria Presenting as Recurrent Jejunitis

발작성 야간혈색소뇨증은 보체 매개성의 만성 혈관내 용혈, 야간 혈색소뇨, 혈전증, 골수부전을 특징으로 하는 매우드문 후천적 조혈모세포 질환이다. 혈전증에 의한 위장관 허혈증은 발작성 야간혈색소뇨증의 합병증으로 알려져 있으나 우리나라 성인에서 이에 대한 보고는 아직 없었다. 저자들은 재발성 공장염을 보인 발작성 야간혈색소뇨증 환자를 경험 하였기에 이를 보고하고자 한다. 원인이 명확하지 않은 공장염이 반복적으로 발생할 경우 드문 원인 중 하나로 발작성 야간혈색소뇨증을 고려해 볼 수 있을 것으로 생각한다.

Eculizumab in Pregnant Patients with Paroxysmal Nocturnal Hemoglobinuria

BackgroundEculizumab, a humanized monoclonal antibody against complement protein C5 that inhibits terminal complement activation, has been shown to prevent complications of paroxysmal nocturnal hemoglobinuria (PNH) and improve quality of life and overall survival, but data on the use of eculizumab in women during pregnancy are scarce.MethodsWe designed a questionnaire to solicit data on pregnancies in women with PNH and sent it to the members of the International PNH Interest Group and to the physicians participating in the International PNH Registry. We assessed the safety and efficacy of eculizumab in pregnant patients with PNH by examining the birth and developmental records of the children born and adverse events in the mothers.ResultsOf the 94 questionnaires that were sent out, 75 were returned, representing a response rate of 80%. Data on 75 pregnancies in 61 women with PNH were evaluated. There were no maternal deaths and three fetal deaths (4%). Six miscarriages (8%) occurred during the first trimester. Requirements for transfusion of red cells increased during pregnancy, from a mean of 0.14 units per month in the 6 months before pregnancy to 0.92 units per month during pregnancy. Platelet transfusions were given in 16 pregnancies. In 54% of pregnancies that progressed past the first trimester, the dose or the frequency of use of eculizumab had to be increased. Low-molecular-weight heparin was used in 88% of the pregnancies. Ten hemorrhagic events and 2 thrombotic events were documented; both thrombotic events occurred during the postpartum period. A total of 22 births (29%) were premature. Twenty cord-blood samples were examined for the presence of eculizumab; the drug was detected in 7 of the samples. A total of 25 babies were breast-fed, and in 10 of these cases, breast milk was examined for the presence of eculizumab; the drug was not detected in any of the 10 breast-milk samples.ConclusionsEculizumab provided benefit for women with PNH during pregnancy, as evidenced by a high rate of fetal survival and a low rate of maternal complications. (ClinicalTrials.gov number, NCT01374360.)

Acute tubular necrosis in a patient with paroxysmal nocturnal hemoglobinuria

Acute renal failure (ARF) is a well-recognized complication of paroxysmal nocturnal hemoglobinuria (PNH). The predominant mechanism is intravascular hemolysis resulting in massive hemoglobinuria ARF. We report a case of acute tubular necrosis (ATN) developed in the absence of overwhelming evidence of intravascular hemolysis in a 21-year-old man with anemia, who was eventually diagnosed to have PNH. The patient presented with rapidly deteriorating renal functions in the background of iron deficiency anemia, which was attributed to reflux esophagitis. There was no clinical or laboratory evidence of intravascular hemolysis. Renal biopsy revealed ATN with deposition of hemosiderin in the proximal tubular epithelial cells. Diagnosis of PNH was confirmed with a positive Ham's test and flow cytometry. Our case emphasizes the need to consider ATN as a possible cause for ARF in patients suspected to have PNH even in the absence of overwhelming evidence of intravascular hemolysis.

Large Clones With PNH-Type Phenotype are Not Common in Patients Presenting With Intra-Abdominal Thrombosis—A Prospective Study

Intra-abdominal thrombosis is a complication of paroxysmal nocturnal hemoglobinuria (PNH). There is scarcity of data on cases presenting with thrombosis in whom PNH is the predisposing factor. We assessed the role of PNH defect in 81 patients with intra-abdominal thrombosis, 44 patients of Budd Chiari syndrome and 37 patients of extra hepatic venous obstruction. Flowcytometry with glycosylphosphatidyl inositol-anchored proteins (GPI-AP)-CD55, -CD59, and -CD16 was performed on all patients and controls to assess the prevalence of deficiencies and PNH-type phenotype clone size. Deficiencies of individual GPI-AP were seen in 17.3% cases versus 3.4% controls. This was due to CD55 deficiency on red blood cells and CD16 deficiency on the granulocytes. Deficiency of multiple GPI-APs was less frequent (3.7% cases). Data of this study indicate that the PNH defect as detected with CD55, CD59, and CD16 is not an important cause of intra-abdominal thrombosis in northwestern India.

Terminal Complement Inhibitor Eculizumab Improves Complement-Mediated Platelet Consumption and Thrombocytopenia in Patients with Paroxysmal Nocturnal Hemoglobinuria (PNH).

Abstract 4030Poster Board III-966PNH is a hematopoietic stem cell disorder in which unregulated activation of the complement system leads to significant morbidities with shortened lifespan. Life threatening thromboembolism (TE) is the most feared complication of PNH, accounting for 45% of patient deaths. Approximately 40% of PNH patients experience a clinically evident TE and 60% of patients without clinically diagnosed TE demonstrate TE by high-sensitivity MRI, indicating the ongoing thrombotic risk in PNH patients. Thrombocytopenia is found in 25-50% of PNH patients at presentation. PNH platelets are extremely sensitive to terminal complement activation, and circulating platelets are activated in thrombocytopenic PNH patients without clinically diagnosed TE. Eculizumab, a monoclonal antibody targeted to complement C5, blocks the production of both C5a and C5b-9, and has been demonstrated to reduce TE events by up to 92% in PNH patients. Eculizumab has also been shown to beneficially impact several prothrombotic processes in PNH patients including hemolysis, nitric oxide consumption, thrombin generation, tissue factor pathways, and inflammation. We hypothesized that terminal complement activation of PNH platelets contributes to ongoing platelet activation, which is reflected by platelet consumption, contributing to chronic thrombocytopenia defined as platelets <100×109/L. This hypothesis was tested by examining whether chronic inhibition of terminal complement activation with eculizumab increases platelet counts in thrombocytopenic PNH patients. The study population was comprised of the 49 thrombocytopenic PNH patients identified from the total 195 patients in the SHEPHERD, TRIUMPH, and Phase 2 eculizumab trials. Platelet counts were measured at baseline, 26 and 52 weeks of eculizumab treatment. At baseline the median platelet count in the thrombocytopenic group was 68×109/L (range 23 to 97). Patients with thrombocytopenia were more likely to have a history of TE than patients with normal platelet counts (45% vs 27%; P<0.022). Treatment with eculizumab markedly inhibited terminal complement activity in all thrombocytopenic patients, as measured by a significant reduction in LDH at 26 and 52 weeks (median values at baseline, 26 weeks, and 52 weeks: 1746 IU/L, 290 IU/L, 286 IU/L, respectively, UNL 220 U/L); P<0.00001 for each time point vs. baseline). Chronic terminal complement inhibition with eculizumab significantly increased platelet counts to a non-thrombocytopenic level in 33% (95% CI: 20-48%) and 36% (95% CI: 22-51%) of thrombocytopenic patients at 26 and 52 weeks, respectively, of treatment. By inhibiting C5 activity, the median platelet counts significantly increased in thrombocytopenic patients from 68×109/L at baseline to 80 and 85×109/L (P<0.001) at 26 and 52 weeks, respectively. Eculizumab treatment significantly increased platelet counts in both thrombocytopenic patients with a history of TE and no history of TE (P<0.05 vs baseline in both groups). Treatment with eculizumab significantly increased platelet counts at 52 weeks in this thrombocytopenic patient population irrespective of a history of bone marrow failure (P<0.05 vs baseline for each group). As expected, there was no apparent impact of terminal complement inhibition on marrow blood cell production as measured by no change in absolute neutrophil count at 26 and 52 weeks. This suggests that the mechanism of platelet increase may be due to inhibition of terminal complement-mediated consumption of platelets in thrombocytopenic patients with PNH. The present study indicates that thrombosis in PNH patients is more frequent in patients with thrombocytopenia. Terminal complement deposition on PNH platelets results in platelet activation which in turn would be expected to result in platelet consumption, suggestive of a chronic prothrombotic state, in PNH patients. Earlier studies have shown that chronic terminal complement inhibition with eculizumab reduces thrombotic risk in patients with PNH. The current study shows that chronic terminal complement inhibition with eculizumab treatment improves pre-existing thrombocytopenia in a significant proportion of patients with PNH. These clinical findings warrant further investigation and suggest that terminal complement C5 activity contributes to platelet activation and consumption with subsequent thrombocytopenia and an increased thrombotic risk in patients with PNH. Disclosures:Socie:Alexion: Consultancy, Membership on an entity's Board of Directors or advisory committees. Muus:Alexion Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees. Schrezenmeier:Alexion: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Höchsmann:Alexion: Honoraria. Hill:Alexion: Honoraria. Bessler:Alexion: Membership on an entity's Board of Directors or advisory committees. Risitano:Alexion Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.

Identification and Clinical Significance of Type II Granulocytes Among Patients with Paroxysmal Nocturnal Hemoglobinuria (PNH) Identified Using Multiparameter High-Sensitivity Flow Cytometry.

Abstract 3015Poster Board II-991PNH is a hematopoietic stem cell disorder in which unregulated activation of terminal complement leads to impaired quality of life and significant ischemic morbidities with shortened lifespan. Life-threatening thromboembolism (TE) is the most feared complication of PNH, accounting for 45% of patient deaths. Thrombosis has been observed in PNH patients regardless of the level of hemolysis. Additionally, platelet activation with subsequent consumption and thrombocytopenia are observed more often in PNH patients at risk for thrombosis.Current laboratory PNH diagnostic methods rely on flow cytometry to characterize PNH clones. PNH granulocytes (Gran) are typically detected using antibodies to a variety of GPI-linked markers including CD55, CD59, CD16, CD24, and CD66b. Recently, FLAER, a fluorescent proaerolysin variant that binds directly to the GPI anchor, has been used to identify and quantify GPI-deficient WBCs at a very high level of sensitivity. Although these markers are well established to detect granulocytes with normal expression of GPI proteins (Type I cells) and complete loss of GPI proteins (Type III cells), less is known about their ability to detect granulocytes with partial loss of GPI proteins (Type II cells). The ability to detect both PNH Type II RBCs and WBCs would provide clinically important information since quantitation of only PNH RBC clones can be confounded by transfusion or hemolysis.We evaluated 2,921 consecutive patient peripheral blood samples submitted for PNH diagnostic testing with a high-sensitivity flow cytometry assay for granulocytes that includes the fluorescent proaerolysin variant (FLAER) with confirmatory lineage-specific antibodies to GPI-linked antigens to distinguish Type I, II and III Gran clones. In addition, standard CD235/CD59 analysis was performed on the RBCs and evaluation with FLAER, CD14 and lineage-specific antibodies was performed on the monocytes. 216 patient samples (7.4%) had a detectable PNH gran clone (≥ 0.01% PNH Type III granulocytes and an absolute count of at least 50 cells). Clinical information was available for 162 of these patients (Table I). Of these samples, nineteen (8.8 %) patients demonstrated a distinct Type II Gran population, ranging in size from 1.2 – 65% (median clone size = 7%). In 4/19 patients, this Type II Gran population represented >50% of the total (Type II + Type III) PNH cells. In 10/19 patients (53%), a type II monocyte population was identified. Evaluation of the granulocyte markers (Table II) showed that the type II gran population was detectable in all cases by FLAER and in decreasing percentage by CD66b (88%), CD55 (50%), CD24 (47%) and CD16 (0%). Patients with Type II Gran clones had a significantly larger median total Gran PNH clone size than those without Type II Gran clones (87% vs. 11%; p= 0.0003), as well as larger median Type II and Type III RBC clones, likely a reflection of the ability to detect type II gran PNH clones with overall larger PNH clone sizes. Patients with Type II Gran clones showed significantly lower median platelet (plt) counts (54 ×109/L) than patients without Type II Gran clones (116×109/L; p< 0.01). Patients with Type II Gran clones had similar peripheral WBC, peripheral RBC, absolute neutrophil count, and hemoglobin (Hgb) compared to patients without Type II Gran clones, suggesting that differences in platelet counts are likely not due to differences in underlying marrow blood cell production. [Display omitted] Type II PNH cells are an important component of the PNH diagnostic evaluation and both RBC and Gran Type II clones should be enumerated. In a large population of patients tested for the presence of PNH clones using a high sensitivity flow cytometry assay, a significant proportion of patients were identified with Type II PNH Gran clones. This study identified FLAER as the best reagent to identify type II Gran PNH clones and showed CD16 was least useful. This study also identified a clinical association between the presence of significant Type II clones and thrombocytopenia, potentially indicative of terminal complement-mediated platelet consumption. These findings are consistent with an increased risk of thrombosis in patients with significant Type II PNH clones. Disclosures:No relevant conflicts of interest to declare.

Home Infusion of Eculizumab: A Unique and Innovative Model of Drug Delivery to Reduce Treatment-Associated Burden and Enhance Quality of Life for Patients with PNH

Paroxysmal Nocturnal Hemoglobinuria (PNH) is an acquired clonal stem cell disease, characterised by intravascular hemolysis, bone marrow failure and lifethreatening thromboses. The median survival is 10–15 years, with the average age of presentation being in the 30's. Symptoms include hemoglobinuria, fatigue, anemia, venous and arterial thromboses, recurrent pain, renal impairment, erectile dysfunction and pulmonary hypertension. The care of a patient with PNH is complex and challenging, as many experience chronic symptoms with periods of acute exacerbations. Historically the management of PNH included bone marrow transplant, blood transfusion and administration of additional supportive therapies, all necessitating regular visits to the hospital. Eculizumab, a monoclonal antibody that binds to the C5 complement component inhibiting the activity of terminal complement and thus preventing the destruction of red blood cells has dramatically altered the management of hemolytic PNH. Clinical trials of eculizumab demonstrated the resolution of the majority of symptoms and complications of PNH and resulted in its approval in the UK in June 2007. Eculizumab is administered as a 30 minute intravenous infusion every 14 days, and under the terms of its current EU licence, must be administered by a healthcare professional. In view of the rarity of PNH there are relatively few specialist Centres for the disease resulting in, patients travelling long distances for review and treatment. In view of the dramatic improvement in symptoms on eculizumab many patients are able to return to a near normal lifestyle. In the UK, Leeds Teaching Hospitals with Healthcare at Home have developed a home infusion programme that ensures safe administration of eculizumab in the patient's home at a time convenient to them, leading to enhanced treatment-associated convenience for patients and their families. Patients then only attend the PNH Centre every 3 months to ensure appropriate monitoring and patient education. A recent survey of patients reports a reduction in treatment-associated burden for PNH patients and their families when receiving infusions at home. 46 patients responded to the survey with just over half receiving eculizumab. Of the 21 patients at the time receiving home infusions 19 found this more convenient than the hospital. Home treatment allows flexibility and for some, the return to full-time employment, with the associated financial benefits and improvement in psychological well-being. Of the 21 patients on home care 7 stated there ability to work was transformed with a further 10 having great improvement. Whilst the purpose of the survey was not to address financial burden, the home infusion programme has anecdotally reduced the financial burden on the patient and their family by eliminating the need for time off work, allowing return to full-time employment, and eliminating the cost of travel to and from the hospital for treatments. No patients reporting negative impact, including effect on social life and family relationships, whilst 15 experienced improvement or complete transformation in both areas. The patients reported confidence in the homecare programme, knowing that a very close working relationship existed between the expert hospital and homecare teams. This innovative programme of medication delivery by a dedicated home nursing team allows patients who have previously struggled to cope with their illness to lead a near normal life with an associated enhancement in quality of life. Patients are able to carry on with activities of daily life, including work, recreational activities and holidays, whilst at the same time ensuring compliance with treatment and therefore allowing maximum therapeutic benefit.

Paroxysmal nocturnal haemoglobinuria presenting as cerebral venous sinus thrombosis

Paroxysmal nocturnal haemoglobinuria (PNH) is associated with anaemia, intravascular haemolysis and venous thrombosis. Cerebral venous sinus thrombosis (CVST) is a late but serious complication of PNH. We for the first time report a young man who presented with CVST and was diagnosed to have PNH after 11 months. We highlight the reasons for delay in the diagnosis and discuss the special issues in the management.