Paul Browne

Long-term safety and efficacy of sustained eculizumab treatment in patients with paroxysmal nocturnal haemoglobinuria.

Paroxysmal nocturnal haemoglobinuria (PNH) is characterized by chronic, uncontrolled complement activation resulting in elevated intravascular haemolysis and morbidities, including fatigue, dyspnoea, abdominal pain, pulmonary hypertension, thrombotic events (TEs) and chronic kidney disease (CKD). The long‐term safety and efficacy of eculizumab, a humanized monoclonal antibody that inhibits terminal complement activation, was investigated in 195 patients over 66 months. Four patient deaths were reported, all unrelated to treatment, resulting in a 3‐year survival estimate of 97·6%. All patients showed a reduction in lactate dehydrogenase levels, which was sustained over the course of treatment (median reduction of 86·9% at 36 months), reflecting inhibition of chronic haemolysis. TEs decreased by 81·8%, with 96·4% of patients remaining free of TEs. Patients also showed a time‐dependent improvement in renal function: 93·1% of patients exhibited improvement or stabilization in CKD score at 36 months. Transfusion independence increased by 90·0% from baseline, with the number of red blood cell units transfused decreasing by 54·7%. Eculizumab was well tolerated, with no evidence of cumulative toxicity and a decreasing occurrence of adverse events over time. Eculizumab has a substantial impact on the symptoms and complications of PNH and results a significant improvement in patient survival.

Long-term effect of the complement inhibitor eculizumab on kidney function in patients with paroxysmal nocturnal hemoglobinuria†‡

Paroxysmal nocturnal hemoglobinuria (PNH) is a debilitating and life‐threatening disease in which lysis of PNH red blood cells frequently manifests with chronic hemolysis, anemia, and thrombosis. Renal damage in PNH is associated with chronic hemosiderosis and/or microvascular thrombosis. We determined the incidence of renal dysfunction or damage, defined by stages of chronic kidney disease (CKD), in a large cohort of PNH patients and evaluated the safety and efficacy of the complement inhibitor eculizumab in altering its progression. Renal dysfunction or damage was observed in 65% of the study population at baseline with 21% of patients with later stage CKD or kidney failure (glomerular filtration rate [GFR] ≤60 ml/min/1.73 m2; Stage 3, 4, or 5). Eculizumab treatment was safe and well‐tolerated in patients with renal dysfunction or damage and resulted in the likelihood of improvement as defined as categorical reduction in CKD stage (P < 0.001) compared with baseline and to placebo (P = 0.04). Improvement in renal function was more commonly seen in patients with baseline CKD Stages 1–2 (67.1% improvement, P < 0.001) although improvement was also observed in patients with CKD Stages 3–4 (P = 0.05). Improvements occurred quickly and were sustained for at least 18 months of treatment. Patients categorized at CKD Stages 3–5 did not worsen during treatment with eculizumab. Overall, 40 (21%) of 195 patients who demonstrated renal dysfunction or damage at baseline were no longer classified as such after 18 months of treatment. Administration of eculizumab to patients with renal dysfunction or damage was well tolerated and was usually associated with clinical improvement. Am. J. Hematol. 85:553–559, 2010.

Disturbance of plasma and platelet thrombospondin levels in sickle cell disease.

Thrombospondin (TSP), a large protein found in platelet α‐granules (as TSP‐1), mediates adhesion of sickle reticulocytes to cultured vascular endothelium. To further explore the physiologic relevance of this observation, we have measured plasma TSP levels and platelet TSP‐1 content in subjects with sickle cell disease. Plasma TSP levels were similar for normal controls (mean 491 ng/ml, range 331–723) and steady‐state HbSS patients (mean 536, range 333–1107) and were significantly (P = 0.012) but variably elevated for HbSS patients presenting with acute painful crisis (mean 868, range 442–2780). Some of these elevated plasma TSP levels reached those previously observed to support maximal red cell adhesion to endothelium in vitro. Compared to normals, both steady‐state and in‐crisis HbSS patients had significantly (P < 0.001) depressed platelet TSP‐1 content (82.6 ± 11.9, 47.1 ± 16.0 and 45.9 ± 20.7 ng/109 platelets, respectively, mean ± SD). HbSC disease patients, all examined during steady state, had low‐normal plasma levels of TSP and either normal or depressed platelet TSP‐1 content. Serial observations on three sickle cell anemia subjects indicated a probable relationship between platelet TSP‐1 release, elevated plasma TSP levels, and acute vasoocclusive episodes. These results suggest a state of ongoing release and depletion of TSP‐1 from activated platelets in patients with sickle cell disease.

The Molecular Pathobiology of Cell Membrane Iron: The Sickle Red Cell as a Model

The molecular pathobiology of membrane-associated iron is clearly illustrated by the sickle red blood cell. The cytosolic aspect of the membranes of these cells carries several discrete iron compartments, including denatured hemoglobin and free heme, as well as molecular iron associated with membrane aminophospholipid and denatured globin. Affinity of the membrane for molecular iron is extraordinarily high and predicted to keep cytosolic free iron concentration < 10(-20) M. Membrane iron is bioactive and able to valence cycle, thus serving as a catalyst for generation of highly reactive hydroxyl radical. As a consequence of this oxidative biochemistry at the cytosol/membrane interface, multiple membrane defects arise that are of pathophysiologic importance. Thus, sickle red cells provide a pathobiologic paradigm for the membrane-damaging effect of iron-mediated targeting of oxidative damage at a sub-cellular level. This is relevant to a variety of biologic conditions accompanied by decompartmentalization of iron.

Response to thalidomide therapy in refractory chronic graft-versus-host disease

Chronic graft-versus-host disease (GVHD) refractory to standard immunosuppressive therapy remains a major cause of morbidity and mortality after allogeneic bone marrow transplantation (BMT). Thalidomide may be effective in some patients with high-risk or refractory chronic GVHD. We report a single-institution study of thalidomide in 37 BMT patients with extensive chronic GVHD refractory to standard immunosuppressive therapy. Acute GVHD occurred in 34 (91%) of patients and evolved progressively into chronic GVHD in 23 (62%) patients. Thalidomide was added to standard immunosuppressive therapy a median of 11 months (range 0–105 months) after the diagnosis of chronic GVHD. Fourteen of 37 (38%) patients responded after introduction of thalidomide (one complete, 13 partial). Ten of 21 (46%) children and four of 16 (25%) adults responded. Responses were seen in eight of 17 (47%) recipients of related donor marrow and six of 20 (30%) recipients of unrelated donor marrow. Eight of 23 (34%) patients with progressive onset of chronic GVHD showed a response. There were no deaths among the responders. The remaining 23 patients (62%) did not respond and of these only two survive, one with progressive scleroderma, and the other with bronchiolitis obliterans. Chronic GVHD with associated infection (most commonly disseminated fungal infection) was a major contributor to mortality in all cases. Overall, after initiation of thalidomide, the 2-year Kaplan–Meier survival was 41% (95% C.I. 24%–59%). We conclude that thalidomide is a useful and well-tolerated therapy for patients with previously treated refractory chronic GVHD, including those with progressive onset of chronic GVHD, recipients of unrelated donor marrow, and children. Earlier introduction of thalidomide as an adjunct to standard immunosuppressive therapy may lead to more frequent responses and possible better survival. Bone Marrow Transplantation (2000) 26, 865–869.

Outbreaks of infectious diseases in stem cell transplant units: a silent cause of death for patients and transplant programmes

Summary:Following the closure of the National Blood and Bone Marrow Transplant Unit in Dublin, because of an outbreak of vancomycin-resistant enterococcal infection, a survey was carried out by the EBMT to investigate the occurrence of outbreaks of infection in SCT units and the impact on patient morbidity, mortality and the administration of the transplant programme over a 10-year period from 1991 to 2001. A total of 13 centres reported 23 outbreaks of infection involving 231 patients: 10 bacterial, eight viral and five fungal outbreaks were reported and 56 deaths were attributed to infection. All fungal and bacterial deaths and the majority of viral deaths occurred in allograft recipients. In all outbreaks, the infection was reported to be hospital acquired and in all the viral, and half the bacterial infections, cross-infection was a major factor. All viral, four of 10 bacterial and three of five fungal outbreaks occurred in HEPA filtered rooms. A total of 12 SCT units reported a partial or total closure. The introduction of mandatory quality management systems such as JACIE should result in a change in attitude to ‘incident reporting’ and together with future surveys should reduce the incidence of infectious outbreaks in SCT units.

Outcomes and prognostic factors of adults with acute lymphoblastic leukemia who relapse after allogeneic hematopoietic cell transplantation. An analysis on behalf of the Acute Leukemia Working Party of EBMT

To describe outcomes, treatment and prognostic factors that influence survival of adult patients with acute lymphoblastic leukemia (ALL), who relapsed after allogeneic hematopoietic cell transplantation (HCT), we retrospectively analyzed 465 ALL adult patients from European Group for Blood and Marrow Transplantation (EBMT) centers who relapsed after a first HCT performed in complete remission (CR1 65%, CR2/3 35%). Salvage treatments were: supportive care (13%), cytoreductive therapy (43%), donor lymphocyte infusion without or with prior chemotherapy (23%) and second HCT (20%). Median time from HCT to relapse was 6.9 months, median follow-up was 46 months and median survival after relapse was 5.5 months. Estimated 1-, 2- and 5-year post-relapse survival was 30±2%, 16±2% and 8±1%, respectively. In a multivariate analysis, adverse factors for survival were: late CR (CR2/3) at transplant (P<0.012), early relapse after transplant (<6.9 months, P <0.0001) and peripheral blast percent at relapse (P <0.0001). On the basis of multivariate model for survival, three groups of patients were identified with estimated 2 year survival of 6±2, 17±3 and 30±7%. Outcome of ALL patients relapsing after HCT is dismal and there is a need for new therapies. Our study provides the standard expectations in ALL relapse and may help in the decision of post-relapse therapy.

Eculizumab, a terminal complement inhibitor, improves anaemia in patients with paroxysmal nocturnal haemoglobinuria

In paroxysmal nocturnal haemoglobinuria (PNH), chronic destruction of PNH red blood cells (RBCs) by complement leads to anaemia and other serious morbidities. Eculizumab inhibits terminal complement‐mediated PNH RBC destruction by targeting C5. In the phase III, double‐blind, placebo‐controlled, TRIUMPH study, eculizumab reduced haemolysis, stabilized haemoglobin levels, reduced transfusion requirements and improved fatigue in patients with PNH. Herein, we explored the effects of eculizumab on measures of anaemia in patients from the TRIUMPH study and the open‐label SHEPHERD study, a more heterogeneous population. Eculizumab reduced haemolysis regardless of pretreatment transfusion requirements and regardless of whether or not patients became transfusion‐dependent during treatment (P < 0·001). Reduction in haemolysis was associated with increased PNH RBC counts (P < 0·001) while reticulocyte counts remained elevated. Eculizumab‐treated patients demonstrated significantly higher levels of haemoglobin as compared with placebo in TRIUMPH and relative to baseline levels in SHEPHERD (P < 0·001 for each study). Eculizumab lowered transfusion requirement across multiple pretreatment transfusion strata and eliminated transfusion support in a majority of both TRIUMPH and SHEPHERD patients (P < 0·001). Patients who required some transfusion support during treatment with eculizumab showed a reduction in haemolysis and transfusion requirements and an improvement in fatigue. Eculizumab reduces haemolysis and improves anaemia and fatigue, regardless of transfusion requirements.

An outbreak of multiply resistant Serratia marcescens : the importance of persistent carriage

An outbreak of multi-resistant Serratia marcescens involving 24 patients occurred in a bone marrow transplant and oncology unit, from September 1998 to June 1999, of whom 14 developed serious infection. This is the first such outbreak described in a BMT unit. All isolates demonstrated the same antimicrobial susceptibility pattern and were the same unusual serotype O21:K14. The antimicrobial susceptibility profile showed reduced susceptibility to ciprofloxacin, gentamicin and piperacillin-tazobactam. As the latter two antimicrobials are part of our empiric therapy for febrile neutropenia, they were substituted with meropenem and amikacin during the outbreak. Investigation revealed breaches in infection control practices. Subsequently, the outbreak was contained following implementation of strict infection control measures. A prominent feature of the outbreak was prolonged carriage in some patients. These patients may have acted as reservoirs for cross-infection. This report also indicates that patients who become colonised with Serratia marcescens may subsequently develop invasive infection during neutropenic periods. Bone Marrow Transplantation (2000) 25, 873–877.

Minimal residual disease detection in childhood acute lymphoblastic leukaemia patients at multiple time-points reveals high levels of concordance between molecular and immunophenotypic approaches

In this single centre study of childhood acute lymphoblastic leukaemia (ALL) patients treated on the Medical Research Council UKALL 97/99 protocols, it was determined that minimal residual disease (MRD) detected by real time quantitative polymerase chain reaction (RQ‐PCR) and 3‐colour flow cytometry (FC) displayed high levels of qualitative concordance when evaluated at multiple time‐points during treatment (93·38%), and a combined use of both approaches allowed a multi time‐point evaluation of MRD kinetics for 90% (53/59) of the initial cohort. At diagnosis, MRD markers with sensitivity of at least 0·01% were identified by RQ‐PCR detection of fusion gene transcripts, IGH/TRG rearrangements, and FC. Using a combined RQ‐PCR and FC approach, the evaluation of 367 follow‐up BM samples revealed that the detection of MRD >1% at Day 15 (P = 0·04), >0·01% at the end of induction (P = 0·02), >0·01% at the end of consolidation (P = 0·01), >0·01% prior to the first delayed intensification (P = 0·01), and >0·1% prior to the second delayed intensification and continued maintenance (P = 0·001) were all associated with relapse and, based on early time‐points (end of induction and consolidation) a significant log‐rank trend (P = 0·0091) was noted between survival curves for patients stratified into high, intermediate and low‐risk MRD groups.