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.

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.

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.

Prenatal Management of Pregnancies at Risk of Fetal Neonatal Alloimmune Thrombocytopenia (FNAIT): Scientific Impact Paper No. 61

WHAT IS IT?: Fetal neonatal alloimmune thrombocytopenia (FNAIT), also known as neonatal alloimmune thrombocytopenia (NAIT) or fetomaternal alloimmune thrombocytopenia (FMAIT), is a rare condition which affects a baby's platelets. This can put them at risk of problems with bleeding, particularly into the brain. One baby per week in the UK may be seriously affected and milder forms can affect one in every 1000 births. HOW IS IT CAUSED?: Platelets are blood cells that are very important in helping blood to clot. All platelets have natural proteins on their surface called human platelet antigens (HPAs). In babies, half of these antigens are inherited from the mother and half from the father. During pregnancy, some of the baby's platelets can cross into the mother's bloodstream. In most cases, this does not cause a problem. But in cases of FNAIT, the mother's immune system does not recognise the baby's HPAs that were inherited from the father and develops antibodies, which can cross the placenta and attack the baby's platelets. These antibodies are called anti-HPAs, and the commonest antibody implicated is anti-HPA-1a, but there are other rarer antibody types. If this happens, the baby's platelets may be destroyed causing their platelet count to fall dangerously low. If the platelet count is very low there is a risk to the baby of bleeding into their brain before they are born. This is very rare but if it happens it can have serious effects on the baby's health. HOW IS IT INHERITED?: A baby inherits half of their HPAs from its mother and half from its father. Consequently, a baby may have different HPAs from its mother. As the condition is very rare, and even if the baby is at risk of the condition we have no way of knowing how severely they will be affected, routine screening is not currently recommended. WHAT CAN BE DONE?: FNAIT is usually diagnosed if a previous baby has had a low platelet count. The parents are offered blood tests and the condition can be confirmed or ruled out. There are many other causes of low platelets in babies, which may also need to be tested for. As the condition is so rare, expertise is limited to specialist centres and normally a haematologist and fetal medicine doctor will perform and interpret the tests together. Fortunately, there is an effective treatment for the vast majority of cases called immunoglobulin, or IVIg. This 'blood product' is given intravenously through a drip every week to women at risk of the condition. It may be started from as early as 16 weeks in the next pregnancy, until birth, which would be offered at around 36-37 weeks. Less common treatments that may be considered depending on individual circumstances include steroid tablets or injections, or giving platelet transfusions to the baby. WHAT DOES THIS PAPER TELL YOU?: This paper considers the latest evidence in relation to treatment options in the management of pregnancies at risk of FNAIT. Specifically, we discuss the role of screening, when IVIg should be started, what dose should be used, and what evidence there is for maternal steroids. We also consider in very rare selected cases, the use of fetal blood sampling and giving platelet transfusions to the baby before birth. Finally, we consider the approaches to blood testing mothers to tell if babies are at risk, which is offered in some countries, and development of new treatments to reduce the risk of FNAIT.

A single unit transfusion policy reduces red cell transfusions in general medical in-patients

BACKGROUND

The NICE guidelines for blood transfusion and the patient blood management recommendations state that a single unit of red cells should be the standard dose for patients with stable anaemia who are not bleeding. Studies have shown that changing clinical transfusion practice can be difficult and that many clinicians' order two units of blood as standard for patients needing a transfusion.

AIM

A collaborative project between NHS Blood and Transplant and Kings College Hospital started in September 2014 to evaluate the impact of a single unit policy on blood usage.

DESIGN METHODS

Training and education was undertaken for clinical staff on eight general medical wards and all staff working in the blood transfusion laboratory. We collected transfusion data for 12 months, (6 months before and after implementation).

RESULTS

There was a decrease of 50% red cell unit usage between the two periods, equating to a unit cost saving of £28 670. The number of single unit transfusions, increased from 30 to 53% whilst the number of two units decreased from 65 to 43% (P < 0.001).

DISCUSSION/CONCLUSION

This project has shown that transfusion practice can be changed and savings in blood usage can be achieved through the successful implementation of the single unit transfusions policy. Key to the implementation was engagement from key medical staff within the medical department in which the policy was implemented and support from the hospital transfusion team. Continued attention and training shall be needed to support these, and implement other, patient blood management recommendations.

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.

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.

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.

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.

Storage of hemopoietic stem cells

BACKGROUND

Autologous, and in some cases allogeneic, hemopoietic stem cells (HSC) are stored for varying periods of time prior to infusion. For periods of greater than 48 h, storage requires cryopreservation. It is essential to optimize cell storage and ensure the quality of the product for subsequent reinfusion.

METHODS

A number of important variables may affect the subsequent quality of infused HSC and therapeutic cells (TC). This review discusses these and also reviews the regulatory framework that now aims to ensure the quality of stem cells and TC for transplantation.

RESULTS

Important variables included cell concentration, temperature, interval from collection to cryopreservation, manipulations performed. They also included rate of freezing and whether controlled-rate freezing was employed. Parameters studied were type of cryoprotectant utilized [dimethyl sulphoxide (DMSO) is most commonly used, sometimes in combination with hydroxyethyl starch (HES)]; and storage conditions. It is also important to assess the quality of stored stem cells. Measurements employed included the total cell count (TNC), mononuclear cell count (MNC), CD34+ cells and colony-forming units - granulocyte macrophage (CFU-GM). Of these, TNC and CD34+ are the most useful. However, the best measure of the quality of stored stem cells is their subsequent engraftment. The quality systems used in stem cell laboratories are described in the guidance of the Joint Accreditation Committee of ISCT (Europe) and the EBMT (JACIE) and the EU Directive on Tissues and Cells plus its supporting commission directives. Inspections of facilities are carried out by the appropriate national agencies and JACIE.

CONCLUSION

For high-quality storage of HSC and TC, processing facilities should use validated procedures that take into account critical variables. The quality of all products must be assessed before and after storage.

alpha-Haemoglobin stabilising protein is a quantitative trait gene that modifies the phenotype of beta-thalassaemia

It has been suggested that altered levels or function of alpha-haemoglobin stabilising protein (AHSP), an erythroid-specific protein that binds specifically to free alpha-(haemo)globin, might account for some of the clinical variability in beta-thalassaemia. To assess the variation of AHSP expression, mRNA levels in circulating reticulocytes of 103 healthy individuals were measured by quantitative reverse transcription-polymerase chain reaction. AHSP expression varied up to threefold, and did not correlate with age or sex. A systematic survey of the AHSP locus identified eight sequence variants, of which six were common. Four common variants, including the longer homopolymer (T18) in the putative promoter, are strongly associated with AHSP expression. Reporter assays in K562 cells showed that the activity of the shorter (T15) reporter was relatively lower than that of the T18 reporter. In a study of nine anaemic patients who were heterozygous for beta-thalassaemia and also heterozygous for the triplicated alpha-globin gene (alpha alpha alpha/alpha alpha), frequency of the shorter homopolymer was higher than expected. AHSP expression is variable, with cis control accounting for some of its variance. In some families, the subtle altered levels in AHSP related to the AHSP genotype appears to be a relevant contributory factor in the haematological phenotype.

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.

Preoperative autologous blood donation for bone marrow harvests: Are we wasting donors' time and blood?

Predeposit autologous blood donation (PAD) is frequently offered to bone marrow donors, but its cost-effectiveness is dubious. We assessed the impact of PAD and bone marrow donation on transfusion requirements; and the use of donated blood units in a retrospective study of 61 bone marrow donors. The mean haemoglobin (Hb) concentration fell from 12.9 to 11.8 g dL(-1) in women who predonated one unit and from 13.2 to 10.9 g dL(-1) in those who predonated two units. In men who donated two units of blood, the Hb concentration decreased to 12.9 g dL(-1). Bone marrow harvest led to a further decline in Hb concentration by 2.3 g dL(-1) in women and by 2.4 g dL(-1) in men. The postharvest Hb fell to <or=9.0 g dL(-1) in 39% of female and in 6% of the male donors; all but one of them had predonated blood. The utilization rate of autologous units was 45.6%, with 55% of women and 24% of men receiving autologous blood. In females, 59% of transfused autologous units were given with the donor's Hb of >or= 9.0 g dL(-1); overtransfusion was even more apparent in men: 71% units were given with a Hb >or= 10.0 g dL(-1). PAD in bone marrow donors is associated with high wastage and increases the likelihood of requiring a transfusion. We recommend that PAD should not be routinely offered to bone marrow donors.

Transfusion-transmitted malaria: current donor selection guidelines are not sufficient

A case of transfusion-transmitted malaria was identified in a 50-year-old male patient with sickle cell disease. The donor was Ghanaian, but had migrated to the UK some years previously and had not left the UK for 8 years. The donor met all of the extant donor selection guidelines [1] and a donation was consequently collected. However, on subsequent investigation of the case, the donor was found to be parasitaemic and have high titre malarial antibodies. As a result of this case, changes to the United Kingdom donor selection guidelines have been proposed. These changes will prevent any such further transmissions.

Reduced-intensity allogeneic hematopoietic stem cell transplantation for myelodysplastic syndrome and acute myeloid leukemia with multilineage dysplasia using fludarabine, busulphan, and alemtuzumab (FBC) conditioning

Reduced-intensity conditioned (RIC) hematopoietic stem cell transplantation (HSCT) has improved the accessibility of transplantation in patients previously ineligible. We report the results of allografting following conditioning with fludarabine, busulphan, and alemtuzumab in 62 patients with myelodysplastic syndromes (MDSs) (matched sibling donors [24] or volunteer unrelated donors [VUDs, 38]). The median age for sibling recipients was 56 years (range, 41-70 years) and for VUD recipients, 52 years (range, 22-65 years), with a median follow-up (survivors) of 524 days (range, 93-1392 days) and 420 days (range, 53-1495 days), respectively. The nonrelapse mortality (NRM) at days 100, 200, and 360 was 0%, 5%, and 5%, respectively, for siblings and 11%, 17%, and 21%, respectively, for VUD. The overall survival at one year was 73% for siblings and 71% for VUDs, with a disease-free survival (DFS) of 61% and 59%, respectively. The prognostic significance of the International Prognostic Scoring System (IPSS) was preserved. Of recipients, 86% achieved full-donor chimerism. The cumulative incidence at day 100 of grades III to IV graft-versus-host disease (GVHD) for VUD recipients was 9% and for sibling recipients, 0%. There were 26 patients (16 sibling and 10 VUD) who received donor lymphocyte infusion (DLI) at a median of 273 days (range, 126-1323 days). RIC allogeneic HSCT using this protocol appears to be safe and permits durable donor engraftment. Longer follow-up is required to confirm any potential survival advantage. (Blood. 2004;104:1616-1623)

Differentially expressed genes in adult familial myelodysplastic syndromes

The precise genetic events leading to myelodysplastic syndromes (MDSs) and leukemic transformation remain poorly defined. Even less is known about adult familial MDS. We report an adult MDS family in whom enriched tissue-specific transcripts were derived by subtractive hybridization of cDNA from the mononuclear and CD34+ cells of affected and unaffected family members. These expression libraries were then hybridized to Genome Discovery arrays containing 18 404 genes and expressed sequence tags, and several clusters of differentially expressed genes were identified. A group of 21 genes was underexpressed (>5-fold) in affected vs unaffected family members, and among these were transcription factors and genes involved in myeloid differentiation, such as ZNF140 and myeloid nuclear differentiation antigen (MNDA). Another group of 36 genes was overexpressed (>5-fold), and these encoded proteins belonging to signaling pathways, such as Ras- and Fos-related genes. The top two genes downregulated in this MDS family, ZNF140 and MNDA, were similarly altered in another MDS family, and in some cases of sporadic MDS. Our data suggest that we have identified genes differentially expressed in adult familial MDS, and that alteration of some of these genes may also be important for the evolution of different stages or severity of sporadic MDS.

Alloimmunization to RhD antigen in RhD-incompatible haemopoietic cell transplants with non-myeloablative conditioning

BACKGROUND AND OBJECTIVES

Following exposure to RhD antigen, anti-D develops in up to 20% of RhD-negative patients on chemotherapy, but seldom in the recipients of haemopoietic cell (HC) or solid-organ transplants. Data on anti-D formation come from HC transplants using myeloablative conditioning; no data are available for the non-myeloablative HC transplants. The two types of transplant have a distinct isohaemagglutinin disappearance rate and different kinetics of post-transplant red-cell engraftment. The objective of the study was to analyse anti-D formation in patients receiving non-myeloablative transplants from RhD-incompatible donors.

MATERIALS AND METHODS

Sixteen patients were analysed: nine RhD-negative recipients of RhD-positive haemopoietic cells; and seven RhD-positive recipients of a graft from a RhD-negative donor. Patients were sequentially tested for irregular antibodies, as well as donor/recipient chimerism by cytogenetics and analysis of DNA variable-number tandem repeats.

RESULTS

Despite having received 7-499 ml of D-positive red cells, none of the RhD-negative recipients developed anti-D. The median follow-up was 202 days. By contrast, anti-D was identified in one of seven RhD-positive recipients of an RhD-negative graft.

CONCLUSIONS

Non-myeloablative conditioning containing fludarabine and/or Campath 1H, with cyclosporin A given post-transplant, effectively prevents anti-D formation in RhD-negative recipients of a RhD-positive graft. However, anti-D developed in an RhD-positive recipient of an RhD-negative graft, who was also exposed to RhD-positive blood products before and after the transplant. Transfusion of RhD-positive products should be avoided in such patients.

Frequent expression of HAGE in presentation chronic myeloid leukaemias

Cancer testis (CT) antigens provide attractive targets for cancer-specific immunotherapy. Although CT genes are expressed in some normal tissues, such as the testis and in some cases placenta, these immunologically protected sites lack MHC I expression and as such, do not present 'self' antigens to T cells. To date, CT genes have been shown to be expressed in a range of solid tumours, but rarely in haematological malignancies. We have extended previous studies to investigate the expression of a comprehensive range of CT genes (MAGE-A1, -A3, -A6, -A12, BAGE, GAGE, HAGE,LAGE-1, NY-ESO-1 and RAGE) for their expression in a cohort of acute and chronic myeloid leukaemia patient samples. CT expression was not detected in 20 normal bone marrow or peripheral blood stem cell samples. In acute myeloid leukaemia (AML) nine of the 26 (35%) samples analysed expressed one or more of the CT genes with six of the samples (23%) expressing HAGE. In chronic myeloid leukaemia (CML) 24 of 42 (57%) presentation chronic myeloid leukaemia (CML) patient samples expressed one or more CT antigen with 23 expressing HAGE. We have shown that HAGE is frequently expressed in CML, and to a lesser extent in AML patient samples. This is the first demonstration of HAGE gene expression in myeloid leukaemia patients and the frequent expression of HAGE at disease presentation opens up the possibility of early immunotherapeutic treatments.

Allogeneic stem cell transplantation in the myelodysplastic syndromes: interim results of outcome following reduced-intensity conditioning compared with standard preparative regimens

Conventional allogeneic stem cell transplantation (SCT) for myelodysplastic syndrome (MDS) is associated with excessive procedure-related mortality. The outcome following volunteer-unrelated donor (VUD) or sibling allogeneic SCT was therefore evaluated in 23 MDS patients conditioned with reduced-intensity regimens (fludarabine/busulphan/Campath-1H) because of advanced age (48 vs 37 years, P = 0.002) and/or co-morbidity (19 vs 3, P < 0.0001) which precluded conventional transplantation, and compared with 29 treated with standard protocols [busulphan/cyclophosphamide (Bu/Cy); Bu/Cy/total-body irradiation/Campath-1G]. Graft-versus-host disease (GVHD) prophylaxis comprised of cyclosporine/methotrexate. One hundred per cent donor engraftment (variable number tandem repeat analysis/cytogenetics/fluorescence in situ hybridization) was achieved in 18/19 (95%) evaluable patients receiving reduced-intensity regimens, although six (32%) have subsequently shown mixed chimaerism. Reduced-intensity conditioning was associated with significantly reduced duration of aplasia, less mucositis, fever, antibiotic, analgesia, parenteral nutrition use, less acute and chronic GVHD, and lower early procedure-related mortality [two (9%) vs nine (31%), P < 0.05]. Six patients relapsed (two standard, four reduced-intensity) and two (reduced-intensity) experienced late graft failure. The 2 year actuarial overall/disease-free survival (OS/DFS) was 48/39% in the reduced-intensity arm and 44/44% in the standard group. The 2 year non-relapse mortality was 31% and 50% respectively. In VUD recipients, OS was superior in the reduced-intensity arm (49%vs 34%). Predictors of DFS included good/intermediate-risk karyotype, low/intermediate-1 International Prognostic Scoring system score, human leucocyte antigen compatibility and attainment of complete remission. Our data demonstrates that VUD or sibling allogeneic SCT following reduced-intensity conditioning is feasible in high-risk MDS patients considered unsuitable for standard transplantation and is associated with comparable 3.5 year DFS to those receiving conventional regimens.

The role of apoptosis, proliferation, and the Bcl-2-related proteins in the myelodysplastic syndromes and acute myeloid leukemia secondary to MDS

Bone marrow CD34(+) cell apoptosis (annexin V), proliferation (Ki-67), and Bcl-2-related protein expression was evaluated by flow cytometry in 102 patients with myelodysplastic syndrome (MDS) and acute myeloid leukemia secondary to MDS (MDS-AML) and in 30 normal donors (NBM). Apoptosis was significantly increased in refractory anemia (RA)/RA with ringed sideroblasts (RARS) (56.9% [20.4%-93.6%]) and refractory anemia with excess blasts (RAEB) (51.2% [25.2%-76. 6%]) compared with NBM (16.7% [3.4%-35.3%], P <.0001). In RA/RARS, apoptosis always exceeded proliferation (Ki-67-positivity, 26.1% [9.5%-47.8%]; apoptosis:proliferation ratio 2.08 [1.15-3.63]); whereas in RAEB, this ratio equalized (1.14 [0.93-2.08]) due to increased proliferation (40.4% [22%-69.5%]). Progression to RAEB in transformation (RAEB-t)/MDS-AML was associated with a significant reduction in apoptosis (22.3% [2.1%-53.2%]; P <.0001) and proliferation (16.8% [1.9%-75.8%); P =.04; ratio 1.69 [0.16-12.21]). Pro-apoptotic (Bax/Bad) versus anti-apoptotic (Bcl-2/Bcl-X) Bcl-2-related protein ratios were increased in RA/RARS compared with NBM (2.57 [1.93-9.42] versus 1.89 [0.65-4.1]; P =.06), whereas disease progression was associated with significantly reduced ratios (1.16 [0.06-3.32]; P <.0001) due primarily to increased Bcl-2 expression. Apoptosis and Bax/Bad:Bcl-2/Bcl-X ratio were inversely correlated with both International Prognostic Scoring System score and cytogenetic risk group; highest levels observed in patients with low score and/or good risk cytogenetics. There was a trend toward an association between Bcl-2-related protein expression and apoptosis (P =.07). This study indicates that MDS progression arises through multiple hits that alter levels of CD34(+) cell apoptosis and proliferation. Early disease is associated with excessive apoptosis and elevated ratio of apoptosis to proliferation. Increased proliferative rates are observed in RAEB, whereas leukemic transformation arises through inhibition of apoptosis rather than excessive cell growth. Although disease progression is accompanied by a fall in pro-apoptotic versus anti-apoptotic Bcl-2-related protein ratios, heterogeneity in patterns of protein expression indicates that factors additional to Bcl-2 family members play a role in the deregulated apoptosis in MDS. (Blood. 2000;96:3932-3938)

The "G-CSF test": the response to a single dose of granulocyte colony-stimulating factor predicts mobilization of hemopoietic progenitors in patients with hematologic malignancies

A significant proportion of patients with hematologic malignancies fail to mobilize sufficient hemopoietic progenitor cells (HPC), thereby restricting wider application of autologous transplantation. It would be of considerable use to develop a test that could be used prospectively to assess an individual patient's capacity to mobilize HPC. Twenty-two patients with lymphoma, myeloma, and chronic lymphocytic leukemia were given a single dose of 12 microg/kg SC of granulocyte colony-stimulating factor (G-CSF). Blood colony-forming unit granulocyte-macrophage (CFU-GM) and CD34+ cells were scored prior to the test dose, and 72, 96, and 120 hours later. The patients were then mobilized with a standard cyclophosphamide and G-CSF regimen and had blood stem cells harvested. Patients were categorized as good, poor, or intermediate mobilizers on the basis of the CFU-GM/CD34+ cell harvest content and the number of aphereses required to reach established threshold counts. The outcome of cyclophosphamide/G-CSF mobilization was correlated with the response to the test dose of G-CSF. Good mobilizers had significantly higher peak CFU-GM values and CFU-GM increment in response to the test dose of G-CSF compared to intermediate and poor mobilizers. A peak CFU-GM count of > or = 250/mL identified the good mobilizers; conversely, all poor mobilizers had a peak CFU-GM count of <102/mL. An increment in CD34+ cells counts of > or = 2.5/microL was only observed in good mobilizers. The "G-CSF" test is a reliable test that can be used successfully for the assessment of mobilizable HPC in patients with hematologic malignancies. It can also be used to stratify patients enrolled in trials of mobilizing agents.

'Low-risk' myelodysplastic syndrome is associated with excessive apoptosis and an increased ratio of pro- versus anti-apoptotic bcl-2-related proteins

We performed flow cytometric analysis of CD34+ cell apoptosis in 59 patients with myelodysplastic syndrome (MDS) or acute myeloid leukaemia (AML) secondary to MDS (MDS-AML) using annexin V-FITC, which binds to exposed phosphatidylserine on apoptotic cells. Apoptosis was significantly increased in FAB subtypes RA, RARS and RAEB (<10% blasts) (56.5% (15.1-86.5%)) compared to normal controls (18.5% (3.4-33.4%), P<0.0001) and RAEB-t/MDS-AML (16% (2.1-43.2%), P<0.0001). There was no correlation between % apoptosis, Full blood count or cytogenetics in any disease category. Two-colour cytometric analysis of permeabilized CD34+ cells stained with antibodies to Bcl-2, Bcl-X (anti-apoptotic), Bax and Bad (pro-apoptotic), demonstrated significantly higher ratios of pro- v anti-apoptotic proteins in early MDS (2.47 (1.19-9.42) compared to advanced disease (1.14 (0.06-3.32), P=0.0001). Moreover, using repeated measures of variants (ANOVA), we found that variations between individual Bcl-2-related proteins differed significantly according to disease subtype (P<0.0005). Our results confirm that CD34+ cell apoptosis was significantly increased in MDS subtypes RA and RARS and fell with disease progression. Early MDS was also associated with a significantly higher CD34+ cell pro- v anti-apoptotic Bcl-2-family-protein ratio than advanced disease. Furthermore, patterns of expression of individual Bcl-2 related proteins differed significantly between different disease categories. However, no correlation between pro- v anti-apoptotic Bcl-2-family-protein ratios and the degree of apoptosis was observed.

Blast counts in blood progenitor cell (BPC) correlate with CD34+ cells and CFU-GM and are useful predictor of haemopoietic recovery after autologous BPC transplantation collections

Assessment of the quality of blood progenitor cell (BPC) collections is based mainly on CD34+ cell enumeration by flow cytometry, or scoring of granulocyte-macrophage colony-forming cells (CFU-GM). A minimum cell dose for haemopoietic recovery can be defined by both assays; however, the CFU-GM assay can not be used for 'real-time' decisions, whereas CD34+ cell scoring requires facilities and expertise which are not universally available. We have investigated the possibility of using morphologically defined blast cells within BPC harvests as a surrogate marker of harvest haemopoietic stem/progenitor cell content, as well as their correlation with CD34+ cells and CFU-GM within the harvests. We have found that blast counts correlate strongly with both CD34+ cell counts and CFU-GM within BPC harvests, as well as with time to granulocyte and platelet recovery after autologous BPC transplantation (ABPCT). Furthermore, we have defined a threshold value of 1.3 x 10(6)/kg blasts, above which there is a high probability of rapid haemopoietic recovery after ABPCT. We conclude that blast count is a simple, rapid and reliable method of assessing BPC harvest quality.

Familial Myelodysplastic Syndrome/Acute Myeloid Leukaemia With Monosomy 7: Report of a New Kindred

Familial juvenile myeloid disorders are uncommon, but better understanding of their basis may lead to crucial advances in the study of leukemogenesis. We report a family with three siblings who died of myelodysplasia and/or acute myeloid leukemia at the age of 10, 11 and 16 years, respectively. Two children died of a fulminant generalized varicella. No somatic constitutional abnormalities were found and histories of exposure to common environmental or occupational mutagens were unremarkable. One of the two tested patients had monosomy of the chromosome 7 in all examined metaphases. Therefore, the clinical and genetic findings are consistent with the "Familial Monosomy 7". A constitutional pericentric inversion of chromosome 9 (p11q13) was detected in the karyotype of the father and both analyzed siblings. In addition, clustering of breast cancer was observed in maternal relatives. As the mode of inheritance and the molecular basis of this disease remain obscure, we believe that it is important to report new cases and attempt to study them as thoroughly as possible. We discuss possible mechanisms of familial tendency to myeloid malignancies.