An epitope-based approach of HLA-matched platelets for transfusion: a noninferiority crossover randomized trial.

Platelet transfusion refractoriness results in adverse outcomes and increased health care costs. Managing refractoriness resulting from HLA alloimmunization necessitates the use of HLA antigen-matched platelets but requires a large platelet donor pool and does not guarantee full matching. We report the first randomized, double-blind, noninferiority, crossover trial comparing HLA epitope-matched (HEM) platelets with HLA standard antigen-matched (HSM) platelet transfusions. Alloimmunized, platelet-refractory, thrombocytopenic patients with aplastic anemia, myelodysplastic syndrome, or acute myeloid leukemia were eligible. HEM platelets were selected using HLAMatchMaker epitope (specifically eplet) matching. Patients received up to 8 prophylactic HEM and HSM transfusions provided in random order. The primary outcome was 1-hour posttransfusion platelet count increment (PCI). Forty-nine patients were randomized at 14 UK hospitals. For intention to treat, numbers of evaluable transfusions were 107 and 112 for HEM and HSM methods, respectively. Unadjusted mean PCIs for HEM and HSM methods were 23.9 (standard deviation [SD], 15) and 23.5 (SD, 14.1), respectively (adjusted mean difference, -0.1; 95% confidence interval [CI], -2.9 to 2.8). Because the lower limit of the 95% CI was not greater than the predefined noninferiority limit, the HEM approach was declared noninferior to the HSM approach. There were no differences in secondary outcomes of platelet counts, transfusion requirements, and bleeding events. Adequate 1-hour PCI was more frequently observed, with a mean number of 3.2 epitope mismatches, compared with 5.5 epitope mismatches for inadequate 1-hour increments. For every additional epitope mismatch, the likelihood of an adequate PCI decreased by 15%. Epitope-matched platelets should be considered to support HLA alloimmunized patients. This trial was registered at www.isrctn.com as #ISRCTN23996532.

Benign ethnic neutropenia: an analysis of prevalence, timing and identification accuracy in two large inner-city NHS hospitals.

BACKGROUND: Benign ethnic neutropenia (BEN) is the most common cause of chronic neutropenia seen in individuals of African, Middle Eastern and West Indian descent. This phenotype is broadly defined by an absolute neutrophil counts (ANC) below 1.8 × 109 cells/L in the absence of other causes, without an increased risk of infection. BEN has been implicated as a potential source of disparity in patients treated with clozapine, the antipsychotic of choice in treatment-resistant schizophrenia. Our main objective was to examine the current level of BEN recognition in a cohort of patients treated with clozapine and the potential impact of unidentified BEN on the initiation and maintenance of clozapine treatment. METHODS: This was an observational, retrospective analysis of patients registered with clozapine haematological monitoring systems in two large mental health trusts, chosen because they serve an ethnically diverse population. The first objective was to establish certified BEN prevalence in current users of clozapine. The second objective was to explore the stage of treatment at which BEN was identified. The third objective was to evaluate the extent of unrecognised BEN in patients registered on the Central Non-Rechallenge Database (CNRD), a database for patients whose haematological parameters fall below set thresholds when receiving clozapine treatment, meaning they cannot ordinarily be prescribed clozapine again. RESULTS: The study population comprised of 2020 patients on the clozapine register. 111 patients were monitored under BEN criteria. BEN was mostly identified after a below threshold haematological result or clozapine rechallenge (68%) compared to at clozapine initiation (32%). Eight of the 18 (42%) black patients registered on the CNRD were classified as BEN after assessment by a haematologist. Of these 8 patients, none would have met CNRD criteria again if monitored with BEN criteria at clozapine initiation. CONCLUSIONS: Current evidence suggests that BEN remains an uncommonly recognised haematological phenotype. Improved timely identification of BEN will reduce unnecessary interruption or discontinuation of clozapine treatment. Our results suggest consideration should also be given to determining BEN status prior to initiating clozapine. Moreover, adoption of current FDA BEN monitoring criteria in the UK may further reduce clozapine discontinuation due to perceived neutropenia as drug toxicity, particularly in treatment-refractory schizophrenia patients.

Passenger lymphocyte thrombocytopenia due to human platelet antigen 3a antibodies: Case report and review of literature.

We report a case of severe acute thrombocytopenia occurring within days after a cadaveric liver transplant, received from a female patient with aplastic anemia who died of intracranial bleeding. The donor, who was homozygous for the ITGA2B*002 (HPA-3b) gene, had developed human platelet antigen (HPA)-3a antibodies, whereas the recipient was homozygous for the ITGA2B*001 (HPA-3a) gene. Thrombocytopenia responded to an infusion of immunoglobulin G. This is the first report of a passenger lymphocyte syndrome manifesting with thrombocytopenia due to anti-HPA-3a. We review the literature on thrombocytopenia in the setting of PLS and discuss the differential diagnosis.

Clozapine-induced agranulocytosis.

Wider use of clozapine, one of the most effective antipshychotic drugs, is precluded by its propensity to cause agranulocytosis. Currently, clozapine is used for treatment-resistant schizophrenia, with mandatory blood count monitoring for the duration of treatment. Agranulocytosis occurs in up to 0.8% of patients and presents a significant medical challenge, despite decreasing mortality rates. In this paper, we review the epidemiology of clozapine-induced agranulocytosis (CLIA), advances in identifying genetic risk factors, and the preventive measures to reduce the risk of CLIA. We discuss the pathogenesis of CLIA, which, despite receiving considerable scientific attention, has not been fully elucidated. Finally, we address the clinical management and suggest the approach to clozapine re-challenge in patients with a previous episode of neutropenia. With a significant proportion of clozapine recipients in Western hemisphere being Black, we comment on the importance of recognizing benign ethnic neutropenia as a potential impediment to clozapine administration. This review aims to aid haematologists and psychiatrists to jointly manage neutropenia and agranulocytosis caused by clozapine.

The Use of Granulocyte Colony-Stimulating Factor in Clozapine Rechallenge: A Systematic Review.

PURPOSE/BACKGROUND: Clozapine is associated with hematological abnormalities, with neutropenia and agranulocytosis of most concern. Granulocyte colony-stimulating factor (G-CSF) has been used to support clozapine rechallenge after neutropenia with the aim of maintaining the neutrophil count. This study aims to explore the practice, use, safety, and efficacy of G-CSF in this context. METHODS/PROCEDURES: We conducted a systematic review to identify all studies investigating or describing G-CSF as a prophylaxis to enable continued clozapine treatment during a rechallenge. FINDINGS/RESULTS: We identified 32 reports of patients who received G-CSF either regularly (n = 23) or as required (n = 9) to support clozapine rechallenge after an episode of neutropenia necessitating discontinuation of clozapine. Seventy-five percent (n = 24) of published cases remained on clozapine with the use of continual prophylactic G-CSF or after single G-CSF administrations (n = 8). Seventy percent (n = 16) of patients in receipt of continual prophylactic G-CSF were successfully maintained on clozapine. However, 1 of the 3 episodes of rechallenge in those with a history of severe agranulocytosis (absolute neutrophil count <0.1 × 10/L) had a recurrence of agranulocytosis at week 9. IMPLICATIONS/CONCLUSIONS: Our findings suggest that G-CSF can sometimes be safely used to support the maintenance of normal neutrophil counts and clozapine use after neutropenia. Publication bias is an important limitation, however. Also, few reports clearly documented the presence or absence of an independent nonclozapine cause of the index neutropenia, which may have increased success rates. Furthermore, adverse events were not systematically recorded. Prospective studies are needed to determine safety because if agranulocytosis occurs on clozapine while supported by G-CSF, there is no obvious alternate rescue therapy to promote granulopoiesis. From the available data, it is not possible to recommend this course of action for someone with a true clozapine agranulocytosis.

Clozapine-Associated Agranulocytosis Treatment With Granulocyte Colony-Stimulating Factor/Granulocyte-Macrophage Colony-Stimulating Factor: A Systematic Review.

PURPOSE/BACKGROUND: Clozapine is associated with hematological abnormalities, notably neutropenia, which may progress to agranulocytosis. Granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) have been used to reduce the frequency and duration of clozapine-associated neutropenia. This review aims to explore the use, efficacy, and tolerability of these cytokines in the treatment of clozapine-associated agranulocytosis. METHODS/PROCEDURES: We conducted a systematic review of published interventional and observational studies, case series, and case reports where G-CSF/GM-CSF was used to treat clozapine-associated agranulocytosis. FINDINGS/RESULTS: We identified 29 reports (40 patients). The median duration of neutrophil recovery time after stopping clozapine and starting cytokine treatment was 7 days (range, 2-13 days) for those with agranulocytosis (absolute neutrophil count < 0.5 × 10 cells/L). Ninety-four percent (n = 29) had no serious adverse reactions, and no deaths occurred. IMPLICATIONS/CONCLUSIONS: Our findings indicate that G-CSF/GM-CSF use is well tolerated and suggest that G-CSF can sometimes be safely used to reduce the duration of neutropenia associated with clozapine use. However, the interpretation of this outcome is difficult, given the likely publication bias for positive outcomes in case reports.

Autoimmune hemolytic anemia after allogeneic hematopoietic stem cell transplantation: analysis of 533 adult patients who underwent transplantation at King's College Hospital.

Autoimmune hemolytic anemia (AIHA) is a recognized complication of hematopoietic stem cell transplantation (HSCT); it is often refractory to treatment and carries a high mortality. To improve understanding of the incidence, risk factors, and clinical outcome of post-transplantation AIHA, we analyzed 533 patients who received allogeneic HSCT, and we identified 19 cases of AIHA after HSCT (overall incidence, 3.6%). The median time to onset, from HSCT to AIHA, was 202 days. AIHA was associated with HSCT from unrelated donors (hazard ratio [HR], 5.28; 95% confidence interval [CI], 1.22 to 22.9; P = .026). In the majority (14 of 19; 74%) of AIHA patients, multiple agents for treatment were required, with only 9 of 19 (47%) patients achieving complete resolution of AIHA. Patients with post-transplantation AIHA had a higher overall mortality (HR, 2.48; 95% CI, 1.33 to 4.63; P = .004), with 36% (4 of 11 cases) of deaths attributable to AIHA.

How we treat delayed haemolytic transfusion reactions in patients with sickle cell disease.

Transfusion therapy is effective in the prevention and treatment of many complications of sickle cell disease (SCD). However, its benefits must be balanced against its risks, including delayed haemolytic transfusion reactions (DHTR). Not only is the relative rate of alloimmunization higher in patients with SCD than in other patient populations, but attendant risks associated with DHTR are even greater in SCD. Clinicians' awareness of DHTR events is poor because symptoms of DHTR mimic acute vaso-occlusive pain and immunohaematology findings are often negative. Transfusions delivered in the acute rather than elective setting appear to confer a higher risk of DHTR. Management of DHTR in SCD depends on the clinical severity, ranging from supportive care to immunosuppression, and optimization of erythropoiesis. DHTR must be considered in any recently transfused patient presenting with acute sickle cell pain. Meticulous documentation of transfusion and immunohaematology history is key. We anticipate an increase in DHTR events in SCD patients with the increasing use of red blood cell transfusion therapy.

Delayed haemolytic transfusion reaction in adults with sickle cell disease: a 5-year experience.

Delayed haemolytic transfusion reactions (DHTR) are potentially life-threatening complications in patients with sickle cell disease (SCD). Between 1 August 2008 and 31 December 2013, 220 of 637 adult patients in our centre had at least one red blood cell (RBC) transfusion in 2158 separate transfusion episodes. Twenty-three DHTR events occurred in 17 patients (13 female) including 15 HbSS, one HbSC and one HbSß(0) thalassaemia, equating to a DHTR rate of 7·7% of patients transfused. Mean interval from RBC transfusion to DHTR event was 10·1 ± 5·4 d, and typical presenting features were fever, pain and haemoglobinuria. Twenty of the 23 (87·0%) DHTR episodes occurred following transfusion in the acute setting. Notably, 11/23 (47·8%) of DHTRs were not diagnosed at the time of the event, most were misdiagnosed as a vaso-occlusive crisis. 16/23 DHTRs had 'relative reticulocytopenia', which was more common in older patients. Seven of 23 episodes resulted in alloantibody formation, and three caused autoantibody formation. DHTRs are a severe but uncommon complication of RBC transfusion in SCD and remain poorly recognized, possibly because they mimic an acute painful crisis. Most of the DHTRs are triggered by RBC transfusion in the acute setting when patients are in an inflammatory state.

Active dendritic cell immunotherapy for glioblastoma: Current status and challenges.

Dendritic cell (DC) immunotherapy is developing as a promising treatment modality for patients with glioblastoma multiforme (GBM). The aim of this article is to review the data from clinical trials and prospective studies evaluating the safety and efficacy of DC vaccines for newly diagnosed (ND)- and recurrent (Rec)-GBM and for other high-grade gliomas (HGGs). By searching all major databases we identified and reviewed twenty-two (n=22) such studies, twenty (n=20) of which were phase I and II trials, one was a pilot study towards a phase I/II trial and one was a prospective study. GBM patients were exclusively recruited in 12/22 studies, while 10/22 studies enrolled patients with any diagnosis of a HGG. In 7/22 studies GBM was newly diagnosed. In the vast majority of studies the vaccine was injected subcutaneously or intradermally and consisted of mature DCs pulsed with tumour lysate or peptides. Median overall survival ranged between 16.0 and 38.4 months for ND-GBM and between 9.6 and 35.9 months for Rec-GBM. Vaccine-related side effects were in general mild (grade I and II), with serious adverse events (grade III, IV and V) reported only rarely. DC immunotherapy therefore appears to have the potential to increase the overall survival in patients with HGG, with an acceptable side effect profile. The findings will require confirmation by the ongoing and future phase III trials.

Blood transfusion usage among adults with sickle cell disease - a single institution experience over ten years.

Transfusion of red blood cells is a major therapeutic option in sickle cell disease (SCD). There is strong evidence for its efficacy, particularly in primary and secondary stroke prevention in children, however, its use in other areas remains controversial. This study assessed the patterns of transfusion in the adult cohort attending King's College Hospital over a 10-year period, from 2000 to 2009. Total blood usage has increased significantly (P = 0·006) during this time, with 78% of the blood received by only 6% of the patients. The increase is explained by increased automated red cell exchange and increased usage for planned and acute transfusions for sickle-related complications.

Successful desensitization to immunoglobulin A in a case of transfusion-related anaphylaxis.

BACKGROUND: A history of anaphylaxis after transfusion of immunoglobulin A (IgA)-containing blood products in selective IgA-deficient (sIgAD) patients can be a major problem, particularly in emergencies, when large quantities of blood products are required. CASE REPORT: A 19-year-old woman with end-stage Type 2 autoimmune hepatitis required liver transplantation as her only remaining treatment option. However, she also had sIgAD, anti-IgA antibodies, and episodes of anaphylaxis after receiving IgA-containing blood products. Liver transplantation would have been extremely challenging due to the difficulty of obtaining sufficient blood products from suitable IgA-deficient donors. Hence, it became imperative to devise a protocol to desensitize her to IgA-containing blood products. RESULTS: Using a continuous infusion of an IgA-enriched (6 mg/mL IgA) immunoglobulin preparation with gradual increases in concentration, she was successfully desensitized to IgA. Consequently, she was able to receive standard platelets, fresh-frozen plasma, and red blood cells with no complications. CONCLUSION: This approach could prove very useful in similar cases that may require administration of large quantities of blood products particularly in emergency lifesaving circumstances.

Need to bleed? Clozapine haematological monitoring approaches a time for change.

Regular haematological monitoring during clozapine treatment reduces the risk of complications and death from clozapine-related blood dyscrasias. However, many patients in the course of clozapine treatment develop neutropenia unrelated to drug treatment which leads to treatment discontinuation. The minimum haematological threshold allowed for the continuation of clozapine treatment was recently lowered in the US, but not in the UK. In this case series, we present four cases where lowering the haematological cut-off to that used in the US, allowed treatment continuation. Lowering the current UK threshold for clozapine cessation could avoid unnecessary interruptions in treatment with minimal impact on safety.

Effects on erythropoiesis of alemtuzumab-containing reduced intensity and standard conditioning regimens.

Haemopoietic cell transplantation (HCT) with reduced-intensity conditioning (RIC) has been associated with delayed disappearance of host anti-A and anti-B isohaemaglutinins and hindrance of donor erythropoiesis in major ABO mismatched transplants. Erythroid recovery, disappearance of recipient type and appearance of donor-type isohaemaglutinins was compared in 84 patients undergoing RIC and 50 patients with standard-conditioning (SCo) HCT. All patients received alemtuzumab as part of their conditioning. The incidence of immune-mediated anaemia and red cell transfusion usage were also compared. Immune factors affecting post-transplant erythroid kinetics showed little variance between different conditioning regimens. Disappearance of recipient isohaemaglutinins and emergence of donor red cells proceeded at similar rates in RIC and SCo transplants; the effects of ABO mismatch were marginal. Pure red cell aplasia, alloimmune haemolysis and autoimmune haemolytic anaemia were not more common in RIC transplants. We believe that alemtuzumab played a critical role in dampening immune reactions of both the host and the donor. Patients in both conditioning groups had similar post-transplant erythroid burst-forming unit (BFU-E) counts; BFU-E chimaerism analysis showed that 90-100% progenitors were of donor origin. However, transfusion requirements were significantly higher in the SCo group, due at least partly to earlier onset of bone marrow hypoplasia.

Mobilization of hematopoietic progenitors in low-grade myelodysplastic syndromes.

Mobilization of hematopoietic progenitors in 15 untreated patients with low-grade myelodysplastic syndrome (IPSS score < or =1) resulted in poor yields in seven patients; moreover, mobilized cells had abnormal cytogenetics and defective in vitro growth. Only three out of 15 patients had adequate progenitor cell collections for potential use in autologous transplantation.

Optimizing outcomes in clozapine rechallenge following neutropenia: a cohort analysis.

OBJECTIVE: Certain patients with treatment-refractory schizophrenia may be rechallenged with clozapine following previous neutropenia. Evidence guiding patient selection and the effectiveness of lithium and granulocyte-colony stimulating factor (G-CSF) in rechallenge is limited, and factors associated with successful outcomes are unclear. METHOD: Outcomes were studied in patients rechallenged with clozapine at a tertiary referral center between January 2007 and December 2013, following 1 or more previous trials terminated due to neutropenia, defined as an absolute neutrophil count (ANC) < 1.5 × 10(9)/L. Demographic characteristics, details of each clozapine trial including ANC, and coprescribed medication were extracted, and factors associated with rechallenge outcomes were examined. RESULTS: Nineteen patients underwent clozapine rechallenge following previous neutropenia; 4 (21%) experienced further neutropenia, 2 of which developed agranulocytosis. Compared to successfully rechallenged patients, unsuccessfully rechallenged patients were significantly older (t = 2.10, P = .05), experienced onset of neutropenia sooner (W = 10.0, P = .03), and were more commonly coprescribed valproate. In addition to 5 patients with benign ethnic neutropenia (BEN), 8 patients not of an ethnicity associated with BEN also had idiopathic low neutrophil counts at baseline; lithium and G-CSF coprescription facilitated successful rechallenge in these patients. CONCLUSIONS: In this selected population, the initial neutropenia was unlikely to be related to clozapine in a substantial proportion of cases. This group was successfully rechallenged following careful consideration of the risks and benefits, and lithium and G-CSF contributed to allowing continued clozapine therapy. In addition to black patients, other ethnic groups can have persistently low ANC unrelated to clozapine.

Granulocyte colony stimulating factor (G-CSF) can allow treatment with clozapine in a patient with severe benign ethnic neutropaenia (BEN): a case report.

Clozapine is the treatment of choice for treatment-resistant schizophrenia, but it is associated with a risk of neutropaenia and agranulocytosis. Clozapine use is regulated by mandatory blood monitoring in the UK, requiring cessation of treatment should the absolute neutrophil count (ANC) drop below specified values. Benign reductions in the ANC in non-white populations are common, and this can preclude a patient from receiving treatment with clozapine. A diagnosis of benign ethnic neutropaenia can reduce these treatment restrictions (UK specific), but the degree of neutropaenia can be significant enough to still prevent treatment. In this report, we show that response to granulocyte colony stimulating factor (G-CSF) may be quite variable and difficult to predict, but with careful monitoring it can be used to increase the ANC count and allow continued treatment with clozapine.

Harvesting, processing and inventory management of peripheral blood stem cells.

By 2003, 97% autologous transplants and 65% of allogeneic transplants in Europe used mobilised peripheral blood stem cells (PBSC). Soon after their introduction in the early 1990's, PBSC were associated with faster haemopoietic recovery, fewer transfusions and antibiotic usage, and a shorter hospital stay. Furthermore, ease and convenience of PBSC collection made them more appealing than BM harvests. Improved survival has hitherto been demonstrated in patients with high risk AML and CML. However, the advantages of PBSC come at a price of a higher incidence of extensive chronic GVHD. In order to be present in the blood, stem cells undergo the process of "mobilisation" from their bone marrow habitat. Mobilisation, and its reciprocal process - homing - are regulated by a complex network of molecules on the surface of stem cells and stromal cells, and enzymes and cytokines released from granulocytes and osteoclasts. Knowledge of these mechanisms is beginning to be exploited for clinical purposes. In current practice, stem cell are mobilised by use of chemotherapy in conjunction with haemopoietic growth factors (HGF), or with HGF alone. Granulocyte colony stimulating factor has emerged as the single most important mobilising agent, due to its efficacy and a relative paucity of serious side effects. Over a decade of use in healthy donors has resulted in vast experience of optimal dosing and administration, and safety matters. PBSC harvesting can be performed on a variety of cell separators. Apheresis procedures are nowadays routine, but it is important to be well versed in the possible complications in order to avoid harm to the patient or donor. To ensure efficient collection, harvesting must begin when sufficient stem cells have been mobilised. A rapid, reliable, standardized blood test is essential to decide when to begin harvesting; currently, blood CD34+ cell counting by flow cytometry fulfils these criteria. Blood CD34+ cell counts strongly correlate with the apheresis yields. These are, in turn, predictive of the speed of haemopoietic recovery after transplantation, which has helped establish the adequate cell dose for transplantation. Following collection, PBSC may be transfused unmanipulated, processed to select specific cell subtypes, or stored for future use. Cryopreservation techniques allow long term storage of stem cells without significant loss of viability. Increasingly demanding calls for safety led to introduction of vapour phase storage, separate storage of infected material, and mandatory quality control measures at all stages of the cryopreservation process and subsequent thawing and transfusion. At the same time, safety of the personnel working in stem cell processing and storage laboratories is safeguarded by a set of regulations devised to minimize the risk of infection, injury or hypoxia. Requirements for quality and safety have been shaped into a number of documents and directives in Europe and USA, emphasising the importance of product traceability, reporting of adverse reactions, quality management systems (standard operating procedures, guidelines, training records, reporting mechanisms and records), requirements for cell reception, quarantine, process control, validation and storage. Establishments that collect, process and store stem cells must be accredited or licensed by appropriate national or international authorities on a regular basis. These regulatory measures have recently become law across the European Union.