The world apheresis association registry, 2023 update

The WAA apheresis registry contains data on more than 140,000 apheresis procedures conducted in 12 different countries. The aim is to give an update of indications, type and number of procedures and adverse events (AEs). MATERIAL AND METHODS: The WAA-registry is used for registration of apheresis procedures and is free of charge. The responsible person for a center can apply at the site www.waa-registry.org RESULTS: Data includes reported AEs from 2012 and various procedures and diagnoses during the years 2018-2022; the latter in total from 27 centers registered a total of 9500 patients (41% women) that began therapeutic apheresis (TA) during the period. A total of 58,355 apheresis procedures were performed. The mean age was 50 years (range 0-94). The most common apheresis procedure was stem cell collection for which multiple myeloma was the most frequent diagnosis (51%). Donor cell collection was done in 14% and plasma exchange (PEX) in 28% of patients; In relation to all performed procedures PEX, using a centrifuge (35%) and LDL-apheresis (20%) were the most common. The main indication for PEX was TTP (17%). Peripheral veins were used in 56% as the vascular access. The preferred anticoagulant was ACD. AEs occurred in 2.7% of all procedures and were mostly mild (1%) and moderate 1.5% (needed supportive medication) and, only rarely, severe (0.15%). CONCLUSION: The data showed a wide range of indications and variability in apheresis procedures with low AE frequency.

When the available blood supply mismatches the needs of the patient

BACKGROUND

Substantial regional differences in the genetic patterns related to blood group have been observed across different continents. This diversity means that the blood supply, as an essential part of patient care, is increasingly impacted by global migration. Consequently, the Austrian blood donor population does not match the immigrant patient population. This mismatch is likely to result in the formation of alloantibodies to red cell antigens in the chronically transfused. Subsequently, major difficulties in providing compatible blood emerge.

MATERIAL AND METHODS

The study included patients of African origin (n=290) and Caucasians who represent the Austrian donor population (n=1,017). Genetic typing was performed for up to 69 blood group polymorphisms with a multiplex sequence specific primer-PCR including high frequency antigens and antigens for which antisera are not commercially available. By assessing differences in antigen frequencies between the two populations, and using these data for prophylactic matching, we aim to develop tools to increase the quality of patient care.

RESULTS

Results indicate various and significant differences (p<0.0001) in antigen frequencies between African patients and the European donor population, especially in the MNS, Duffy, Knops and Rhesus systems.

DISCUSSION

Our data highlight the importance of matching the donor population to the demographics of the patient population. In addition, it underlines the need to recruit donors of African origin and to focus on the upcoming challenges, such as malaria semi-immunity and a significantly higher rate of infectious disease in this population. It is also recommended to apply extended genetic typing to detect rare blood types, and (cryo)storage of rare blood in national and international rare blood banks. Co-operation with regional blood banks should also be encouraged.

Guidelines on the Use of Therapeutic Apheresis in Clinical Practice - Evidence-Based Approach from the Writing Committee of the American Society for Apheresis: The Ninth Special Issue

The American Society for Apheresis (ASFA) Journal of Clinical Apheresis (JCA) Special Issue Writing Committee is charged with reviewing, updating, and categorizing indications for the evidence-based use of therapeutic apheresis (TA) in human disease. In the Ninth Edition, the JCA Special Issue Writing Committee has incorporated systematic review and evidence-based approaches in the grading of evidence and categorization of apheresis indications to make recommendations on the use of apheresis in a wide variety of diseases and conditions. This edition has largely maintained the general layout and concept of a fact sheet introduced in the Fourth Edition (2007). Each fact sheet succinctly summarizes the evidence for the use of TA in a specific disease or medical condition. The Ninth Edition of the JCA Special Issue comprises 91 fact sheets and 166 graded and categorized indications. This includes seven new fact sheets, nine new indications on existing fact sheets, and eight changes in the category for existing indications. The Ninth Edition of the JCA Special Issue seeks to continue to serve as a key resource that guides the utilization of TA in the treatment of human disease.

Incidence and Risk Factors of Venous Thromboembolism in Childhood Acute Lymphoblastic Leukaemia - a Population-Based Analysis of the Austrian Berlin-Frankfurt-Münster (BFM) Study Group

Venous thromboembolism (VTE) is a well-known complication of the treatment of pediatric acute lymphoblastic leukemia (ALL). We analyzed 1026 ALL patients 1-18-years-old, who were enrolled into the AIEOP-BFM ALL 2000 or 2009 studies in Austria, with regard to the incidence and risk factors of VTE. The 2.5-year cumulative incidence (CI) of VTE ≥ grade 2 was 4%±1% (n = 36/1026). Twenty VTE (56%) were found in the central nervous system (19 cerebral venous sinus and 1 cortical vein thrombosis), and 16 (44%) at other sites (7 deep vein thromboses (DVT) of the lower extremity, 4 DVT of the upper extremity, 4 central venous line-thromboses, 1 pulmonary embolism). Most VTE occurred during induction and early consolidation therapy (81%) and were associated with L-asparaginase within 4 and corticosteroids withing 1 week(s) preceding the event (89 and 86%, respectively). In multivariable analysis, two independent risk factors were found. Patients 10-18-years-old had an increased (hazard-ratio: 2.156, p = 0.0389), whereas treatments in trial AIEOP-BFM ALL 2009 had a lower risk for VTE (hazard-ratio: 0.349, p = 0.0270). In conclusion, the 2.5-year CI of VTE among our pediatric patient cohort was <5% and adolescent age was the main patient-related risk factor. This older age group might benefit from primary prophylactic measures.

Rapid and sustained T cell-based immunotherapy against invasive fungal disease via a combined two step procedure

Introduction

Aspergillus fumigatus (Asp) infections constitute a major cause of morbidity and mortality in patients following allogeneic hematopoietic stem cell transplantation (HSCT). In the context of insufficient host immunity, antifungal drugs show only limited efficacy. Faster and increased T-cell reconstitution correlated with a favorable outcome and a cell-based therapy approach strongly indicated successful clearance of fungal infections. Nevertheless, complex and cost- or time-intensive protocols hampered their implementation into clinical application.

Methods

To facilitate the clinical-scale manufacturing process of Aspergillus fumigatus-specific T cells (ATCs) and to enable immediate (within 24 hours) and sustained (12 days later) treatment of patients with invasive aspergillosis (IA), we adapted and combined two complementary good manufacturing practice (GMP)-compliant approaches, i) the direct magnetic enrichment of Interferon-gamma (IFN-γ) secreting ATCs using the small-scale Cytokine Secretion Assay (CSA) and ii) a short-term in vitro T-cell culture expansion (STE), respectively. We further compared stimulation with two standardized and commercially available products: Asp-lysate and a pool of overlapping peptides derived from different Asp-proteins (PepMix).

Results

For the fast CSA-based approach we detected IFN-γ⁺ ATCs after Asp-lysate- as well as PepMix-stimulation but with a significantly higher enrichment efficiency for stimulation with the Asp-lysate when compared to the PepMix. In contrast, the STE approach resulted in comparably high ATC expansion rates by using Asp-lysate or PepMix. Independent of the stimulus, predominantly CD4⁺ helper T cells with a central-memory phenotype were expanded while CD8⁺ T cells mainly showed an effector-memory phenotype. ATCs were highly functional and cytotoxic as determined by secretion of granzyme-B and IFN-γ.

Discussion

For patients with IA, the immediate adoptive transfer of IFN-γ⁺ ATCs followed by the administration of short-term in vitro expanded ATCs from the same donor, might be a promising therapeutic option to improve the clinical outcome.

Relapsed acute lymphoblastic leukaemia after allogeneic stem cell transplantation: a therapeutic dilemma challenging the armamentarium of immunotherapies currently available (case reports)

While survival rates in paediatric acute lymphoblastic leukaemia (ALL) nowadays exceed 90%, systemic ALL relapse, especially after haemopoietic stem cell transplantation (HSCT), is associated with a poor outcome. As there is currently no standardized treatment for this situation, individualized treatment is often pursued. Exemplified by two clinical scenarios, the aim of this article is to highlight the challenge for treating physicians to find a customized treatment strategy integrating the role of conventional chemotherapy, immunotherapeutic approaches and second allogeneic HSCT. Case 1 describes a 2-year-old girl with an early isolated bone marrow relapse of an infant KMT2A-rearranged B-cell precursor ALL after allogeneic HSCT. After bridging chemotherapy and lymphodepleting chemotherapy, chimeric antigen receptor (CAR) T-cells (tisagenlecleucel) were administered for remission induction, followed by a second HSCT from the 9/10 human leukocyte antigen (HLA)-matched mother. Case 2 describes a 16-year-old girl with a late, isolated bone marrow relapse of B-cell precursor ALL after allogeneic HSCT who experienced severe treatment toxicities including stage IV renal insufficiency. After dose-reduced bridging chemotherapy, CAR T-cells (tisagenlecleucel) were administered for remission induction despite a CD19^- clone without prior lymphodepletion due to enhanced persisting toxicity. This was followed by a second allogeneic HSCT from the haploidentical mother. While patient 2 relapsed around Day + 180 after the second HSCT, patient 1 is still in complete remission >360 days after the second HSCT. Both cases demonstrate the challenges associated with systemic ALL relapse after first allogeneic HSCT, including chemotherapy-resistant disease and persisting organ damage inflicted by previous therapy. Immunotherapeutic approaches, such as CAR T-cells, can induce remission and enable a second allogeneic HSCT. However, optimal therapy for systemic ALL relapse after first HSCT remains to be defined.

Organizational characteristics of European pediatric onco-critical care: An international cross-sectional survey

BACKGROUND

Intensified treatment protocols have improved survival of pediatric oncology patients. However, these treatment protocols are associated with increased treatment-related morbidity requiring admission to pediatric intensive care unit (PICU). We aimed to describe the organizational characteristics and processes of care for this patient group across PICUs in Europe.

METHODS

A web-based survey was sent to PICU directors or representative physicians between February and June 2021.

RESULTS

Responses were obtained from 77 PICUs of 12 European countries. Organizational characteristics were similar across the different countries of Europe. The median number of PICU beds was 12 (IQR 8-16). The majority of the PICUs was staffed by pediatric intensivists and had a 24/7 intensivist coverage. Most PICUs had a nurse-to-patient ratio of 1:1 or 1:2. The median numbers of yearly planned and unplanned PICU admissions of pediatric cancer patients were 20 (IQR 10-45) and 10 (IQR 10-30, respectively. Oncology specific practices within PICU were less common in participating centres. This included implementation of oncology protocols in PICU (30%), daily rounds of PICU physicians on the wards (13%), joint mortality and morbidity meetings or complex patients' discussions (30% and 40%, respectively) and participation of parents during clinical rounds (40%).

CONCLUSION

Our survey provides an overview on the delivery of critical care for oncology patients in PICU across European countries. Multidisciplinary care for these vulnerable and challenging patients remains complex and challenging. Future studies need to determine the effects of differences in PICU organization and processes of care on patients' outcome.

The report from ASFA COVID-19 taskforce: Considerations and prioritization on apheresis procedures during the SARS-CoV-2 coronavirus disease (COVID-19) pandemic

Since vaccination for SARS‐CoV‐2 coronavirus started, the trajectory of patient numbers infected with the virus has improved once; however, variants of SARS‐CoV‐2 have emerged and more people have been infected; therefore, pandemic status is still far from resolution. Government and social efforts to prevent coronavirus infection continue in most states in the US and globally even after the Centers for Disease Control and Prevention declared some restriction relief for fully vaccinated people in March 2021. Healthcare institutions and various professional organizations have developed guidelines or policies to prevent the spread of these coronaviruses in the setting of apheresis. In this report, the issues that apheresis services may encounter under the current COVID‐19 (SARS‐CoV‐2 coronavirus disease) pandemic will be discussed with potential strategies that can be adapted for efficient and optimum use of apheresis resources.

Therapeutische Apheresen

Apheresen können ihre therapeutische Wirkung entfalten durch die Entfernung von pathologischen Komponenten, den Austausch von krankhaften Komponenten oder die Entnahme von kranken Komponenten, um sie außerhalb des Körpers zu behandeln. Der Beitrag stellt die verschiedenen Verfahren und Einsatzmöglichkeiten vor.

Analyses of registry data of patients with anti-GBM and antineutrophil cytoplasmatic antibody-associated (ANCA) vasculitis treated with or without therapeutic apheresis

Therapeutic apheresis (TA) as a treatment for antibody-associated vasculitis (AAV) was questioned by the PEXIVAS although the MEPEX study favored TA. The aim of this study was to evaluate the efficacy of TA to improve renal function in patients consecutively included in the WAA-apheresis registry versus patients not treated with TA.

MATERIALS AND METHODS

Included were 192 patients that suffered from anti-glomerular basement membrane disease (anti-GBM, n = 28) and antineutrophil cytoplasmic antibody-associated vasculitis of MPO or PR3 origin. Of these 119 had performed TA and the other 73 had not performed TA for theses diagnoses (CTRL).

RESULTS

Elderly had an increased risk to die within 12 months (p = 0.002). All 28 anti-GBM had renal involvement, 21 dialysis dependent. At 3 month nine (36 %) did not need dialysis. Baseline data regarding renal function of AAV patients, subtype MPO and PR3, were worse in the TA groups than in CTRL. Recovery out of dialysis was better for the PR3-TA group compared with 1) the controls of MEPEX (RR 0.59, CI 0.43-0.80) and 2) the MPO-TA patients (RR 0.28, CI 0.12-0.68). The MPO-TA recovered similarly as the MEPEX-CTRL. Renal function improved most for TA-patients from baseline during the first 3 months (MPO-TA and PR3-TA) and stabilized thereafter and less for MPO-CTRL and PR3-CTRL.

CONCLUSION

PR3-TA patients seem to have best chances to get out of dialysis. PR3-TA and MPO-TA improved residual renal function better than CTRL. The present study recommends reconsiderations to use TA for AAV especially those with PR3-vasculitis with severe renal vasculitis.

Analysis of extracorporeal photopheresis within the frame of the WAA register

The aim of the study was to investigate safety and if extracorporeal photopheresis (ECP) may change health criteria (HC) and quality of life (QoL).

MATERIAL AND METHOD

560 patients (33 % women) were treated with ECP for a total of 13,871 procedures during a 17-years period. Mean age was 48 years (±18, range 3-81 years). Self-estimation of QoL was graded: 0 (suicidal) up to 10 (best ever) and HC: 0 (Bed ridden, ICU condition) up to 10 (athletic). Adverse events were analyzed. ANOVA and paired comparisons were performed.

RESULTS

Patients were treated due to graft versus host disease (GVHD, n = 317), skin lymphoma (n = 70), solid organ transplants (n = 47), skin diseases (n = 20) and other diseases (n = 106). Adverse events (AEs) were registered in 5.4 % of the first treatments and in 1.2 % of the subsequent procedures. Severe AEs were present in 0.04 % of all procedures. No patient died due to the procedure. Tingling and stitching were the most common AE. For those with GVHD an improvement was noticed within approximately 10 procedures of ECP in the severity stage, QoL (from a mean of 6.1 to 6.8, p < 0.002) and the HC (6.1 -> 6.4, p < 0.014) and improved further with added procedures.

CONCLUSION

Photopheresis is an established therapy with few side effects. The present study of soft variables indicate that GVHD shows benefits upon ECP within approximately 10 procedures in regard to the severity of mainly skin GVHD, and lower baseline levels of HC and QoL.

Using the World Apheresis Association Registry Helps to Improve the Treatment Quality of Therapeutic Apheresis

Therapeutic apheresis (TA) is prescribed to patients that suffer from a severe progressive disease that is not sufficiently treated by conventional medications. A way to gain more knowledge about this treatment is usually by the local analysis of data. However, the use of large quality assessment registries enables analyses of even rare findings. Here, we report some of the recent data from the World Apheresis Association (WAA) registry. Data from >104,000 procedures were documented, and TA was performed on >15,000 patients. The main indication for TA was the collection of autologous stem cells (45% of patients) as part of therapy for therapy. Collection of stem cells from donors for allogeneic transplantation was performed in 11% of patients. Patients with indications such as neurological diseases underwent plasma exchange (28%). Extracorporeal photochemotherapy, lipid apheresis, and antibody removal were other indications. Side effects recorded in the registry have decreased significantly over the years, with approximately only 10/10,000 procedures being interrupted for medical reasons.

Conclusion

Collection of data from TA procedures within a multinational and multicenter concept facilitates the improvement of treatment by enabling the analysis of and feedback on indications, procedures, effects, and side effects.

Update to the ASFA guidelines on the use of therapeutic apheresis in ANCA-associated vasculitis

Since 1986, the American Society for Apheresis (ASFA) has published practice guidelines on the use of therapeutic apheresis in the Journal of Clinical Apheresis (JCA) Special Issue. Since 2007, updated guidelines have been published every 3 years to reflect current evidence based apheresis practice with the most recent edition (8th) published in 2019. With each edition, the guidelines are reviewed and updated based on any newly published literature since the last review. The PEXIVAS study, an international, randomized controlled trial comparing therapeutic plasma exchange (TPE) vs no TPE and standard vs reduced dose steroid regimen on the primary composite outcome of end stage renal disease or death in patients with ANCA-associated vasculitis (AAV), was published in February 2020. This study represents the largest study on the role of therapeutic apheresis in AAV published to date and prompted the JCA Special Issue Writing Committee to reassess the current AAV fact sheet for updates based on this newly available evidence. This interim fact sheet summarizes current ASFA recommendations for the evidence-based use of therapeutic apheresis in AAV and supersedes the recommendations published in the 2019 guidelines.

Guidelines on the Use of Therapeutic Apheresis in Clinical Practice - Evidence-Based Approach from the Writing Committee of the American Society for Apheresis: The Eighth Special Issue

The American Society for Apheresis (ASFA) Journal of Clinical Apheresis (JCA) Special Issue Writing Committee is charged with reviewing, updating and categorizing indications for the evidence-based use of therapeutic apheresis (TA) in human disease. Since the 2007 JCA Special Issue (Fourth Edition), the committee has incorporated systematic review and evidence-based approaches in the grading and categorization of apheresis indications. This Eighth Edition of the JCA Special Issue continues to maintain this methodology and rigor in order to make recommendations on the use of apheresis in a wide variety of diseases/conditions. The JCA Eighth Edition, like its predecessor, continues to apply the category and grading system definitions in fact sheets. The general layout and concept of a fact sheet that was introduced in the Fourth Edition, has largely been maintained in this edition. Each fact sheet succinctly summarizes the evidence for the use of TA in a specific disease entity or medical condition. The Eighth Edition comprises 84 fact sheets for relevant diseases and medical conditions, with 157 graded and categorized indications and/or TA modalities. The Eighth Edition of the JCA Special Issue seeks to continue to serve as a key resource that guides the utilization of TA in the treatment of human disease.

Post-transplant Replication of Torque Teno Virus in Granulocytes

Torque Teno virus (TTV) in humans is characterized by ubiquitous occurrence in peripheral blood (PB), without any related disease described to date. Several studies reported a significant increase of TTV plasma DNA levels in allogeneic transplant recipients, and suggested a correlation of elevated virus titers with immunosuppression and transplant-related complications. However, the site of viral replication in this setting has remained unclear. We have studied TTV in serial plasma specimens derived from 43 pediatric allogeneic hematopoietic stem cell transplantation (HSCT) recipients by RQ-PCR, and found increasing TTV-DNA levels in all patients post-transplant, with a peak around day +100 and maximum virus copy numbers reaching 4 × 10E9/ml. To assess whether the virus replicates in PB-cells, leukocyte subsets including granulocytes, monocytes, NK-cells, T- and B-lymphocytes were serially isolated by flow-sorting for TTV analysis in 19 patients. The virus was undetectable in most cell types, but was identified in granulocytes in all instances, revealing a median DNA copy number increase of 1.8 logs between days +30–100 post-transplant. Our data therefore provide evidence for TTV replication in granulocytes in this setting. In a control cohort of immunocompetent children and in HSCT recipients before day +30, TTV positivity in granulocytes was less common (33%), and the copy numbers were considerably lower. However, rising TTV replication about 2 weeks after granulocyte engraftment (>500 cells/μl) was observed suggesting that granulocyte recovery might be required for TTV expansion in severely immunosuppressed transplant recipients.

Volcanic ash supports a diverse bacterial community in a marine mesocosm

Shallow-water coral reef ecosystems, particularly those already impaired by anthropogenic pressures, may be highly sensitive to disturbances from natural catastrophic events, such as volcanic eruptions. Explosive volcanic eruptions expel large quantities of silicate ash particles into the atmosphere, which can disperse across millions of square kilometres and deposit into coral reef ecosystems. Following heavy ash deposition, mass mortality of reef biota is expected, but little is known about the recovery of post-burial reef ecosystems. Reef regeneration depends partly upon the capacity of the ash deposit to be colonised by waterborne bacterial communities and may be influenced to an unknown extent by the physiochemical properties of the ash substrate itself. To determine the potential for volcanic ash to support pioneer bacterial colonisation, we exposed five well-characterised volcanic and coral reef substrates to a marine aquarium under low light conditions for 3 months: volcanic ash, synthetic volcanic glass, carbonate reef sand, calcite sand and quartz sand. Multivariate statistical analysis of Automated Ribosomal Intergenic Spacer Analysis (ARISA) fingerprinting data demonstrates clear segregation of volcanic substrates from the quartz and coral reef substrates over 3 months of bacterial colonisation. Overall bacterial diversity showed shared and substrate-specific bacterial communities; however, the volcanic ash substrate supported the most diverse bacterial community. These data suggest a significant influence of substrate properties (composition, granulometry and colour) on bacterial settlement. Our findings provide first insights into physicochemical controls on pioneer bacterial colonisation of volcanic ash and highlight the potential for volcanic ash deposits to support bacterial diversity in the aftermath of reef burial, on timescales that could permit cascading effects on larval settlement.

Cost-Effectiveness of Defibrotide in the Prophylaxis of Veno-Occlusive Disease after Pediatric Allogeneic Stem Cell Transplantation

Veno-occlusive disease (VOD) remains a serious complication after allogeneic hematopoietic stem cell transplantation (HSCT). Prophylactic use of defibrotide (DF) might further reduce VOD rates but has no impact on the incidence of severe VOD or VOD-associated mortality. We investigated the cost-effectiveness of prophylactic DF according to the British Committee for Standards in Haematology/British Society for Blood and Marrow Transplantation guidelines in 348 children who underwent transplantation between 2001 and 2014 in our hospital, 138 of whom were at risk for VOD. The VOD incidence was 7.4% for the total cohort. Patients at risk had a higher incidence of VOD compared with patients without risk factors (15.2% versus 2.4%, P < .0001). VOD occurred more often in patients after busulfan-based myeloablative conditioning than in patients after total body irradiation (11.2% versus 3.5%, P = .001). Donor types or the transplantation-related mortality (TRM) risk score did not correlate with VOD incidence. In 81% of patients who responded to therapeutic DF, VOD resolved completely. Overall VOD-associated mortality was .3% for the complete cohort, 3.7% for patients diagnosed with VOD, and 20% for patients with severe VOD. Neither the cumulative incidence of TRM (19% ± 8% versus 17% ± 2%, P = .706) nor the median length of hospitalization differed between patients with VOD and patients without. The median costs per HSCT in patients with VOD were about one-third higher than the overall median costs per transplantation at our institution. The calculated total costs of prophylactic DF treatment for 138 patients at risk was almost 6 times as high as the incremental costs for patients with VOD. We conclude that prophylactic DF for children at risk for VOD is not cost-effective with respect to TRM and length of hospital stay.

Guidelines on the Use of Therapeutic Apheresis in Clinical Practice-Evidence-Based Approach from the Writing Committee of the American Society for Apheresis: The Seventh Special Issue

The American Society for Apheresis (ASFA) Journal of Clinical Apheresis (JCA) Special Issue Writing Committee is charged with reviewing, updating, and categorizing indications for the evidence-based use of therapeutic apheresis in human disease. Since the 2007 JCA Special Issue (Fourth Edition), the Committee has incorporated systematic review and evidence-based approaches in the grading and categorization of apheresis indications. This Seventh Edition of the JCA Special Issue continues to maintain this methodology and rigor to make recommendations on the use of apheresis in a wide variety of diseases/conditions. The JCA Seventh Edition, like its predecessor, has consistently applied the category and grading system definitions in the fact sheets. The general layout and concept of a fact sheet that was used since the fourth edition has largely been maintained in this edition. Each fact sheet succinctly summarizes the evidence for the use of therapeutic apheresis in a specific disease entity. The Seventh Edition discusses 87 fact sheets (14 new fact sheets since the Sixth Edition) for therapeutic apheresis diseases and medical conditions, with 179 indications, which are separately graded and categorized within the listed fact sheets. Several diseases that are Category IV which have been described in detail in previous editions and do not have significant new evidence since the last publication are summarized in a separate table. The Seventh Edition of the JCA Special Issue serves as a key resource that guides the utilization of therapeutic apheresis in the treatment of human disease. J. Clin. Apheresis 31:149-162, 2016. © 2016 Wiley Periodicals, Inc.

Relevance of flow cytometric enumeration of post-thaw leucocytes: influence of temperature during cell staining on viable cell recovery

BACKGROUND AND OBJECTIVES

Our post-thaw cell recovery rates differed substantially in interlaboratory comparisons of identical samples, potentially due to different temperatures during cell staining.

MATERIALS AND METHODS

Viable CD34(+) cells and leucocyte (WBC) subtypes were quantified by multiparameter single-platform flow cytometry in leucapheresis products collected from 30 adult lymphoma and myeloma patients, and from 10 paediatric patients. After thawing, cells were prepared for analysis within 30 min between thawing and acquisition, at either 4°C or at room temperature.

RESULTS

For cell products cryopreserved in conventional freezing medium (10% final DMSO), viable cell recovery was clearly lower after staining at 4°C than at RT. Of all WBC subtypes analysed, CD4(+) T cells showed the lowest median recovery of 4% (4°C) vs. 25% (RT), followed by CD3, CD34 and CD8 cells. The recovery was highest for CD3γδ cells with 44% (4°C) vs. 71% (RT). In the 10 samples cryopreserved in synthetic freezing medium (5% final DMSO), median recovery rates were 89% for viable CD34 (both at 4°C and RT) and 79% (4°C) vs 68% (RT) for WBC.

CONCLUSIONS

The post-thaw environment and, potentially, the cryoprotectant impact the outcome of cell enumeration, and results from the analysis tube may not be representative of the cells infused into a patient.

Adverse events in apheresis: An update of the WAA registry data

Apheresis with different procedures and devices are used for a variety of indications that may have different adverse events (AEs). The aim of this study was to clarify the extent and possible reasons of various side effects based on data from a multinational registry. The WAA-apheresis registry data focus on adverse events in a total of 50846 procedures in 7142 patients (42% women). AEs were graded as mild, moderate (need for medication), severe (interruption due to the AE) or death (due to AE). More AEs occurred during the first procedures versus subsequent (8.4 and 5.5%, respectively). AEs were mild in 2.4% (due to access 54%, device 7%, hypotension 15%, tingling 8%), moderate in 3% (tingling 58%, urticaria 15%, hypotension 10%, nausea 3%), and severe in 0.4% of procedures (syncope/hypotension 32%, urticaria 17%, chills/fever 8%, arrhythmia/asystole 4.5%, nausea/vomiting 4%). Hypotension was most common if albumin was used as the replacement fluid, and urticaria when plasma was used. Arrhythmia occurred to similar extents when using plasma or albumin as replacement. In 64% of procedures with bronchospasm, plasma was part of the replacement fluid used. Severe AEs are rare. Although most reactions are mild and moderate, several side effects may be critical for the patient. We present side effects in relation to the procedures and suggest that safety is increased by regular vital sign measurements, cardiac monitoring and by having emergency equipment nearby.

Robust multi-parameter single-platform quantification of myeloid and B-lymphoid CD34 progenitor cells in all clinical CD34 cell sources and in thawed PBSC

As B-lymphoid progenitor cells do not give rise to in vitro colony formation and are unlikely to support myeloid engraftment, we validated a five-color extension of the single platform Stem Cell Enumeration (SCE) kit, to routinely quantify myeloid and B-lymphoid progenitor cells. Fresh samples (n > 20 each) of granulocyte colony stimulating factor mobilized blood (peripheral blood (PB)), cord blood (CB), bone marrow (BM), and apheresis products (APs) were stained in TruCOUNT™ tubes and the results were compared with those from the two-color CD45/CD34 reagent combination and the three-color SCE kit. To address repeatability, 10 samples from one AP were prepared by four technicians. Aliquots (n = 15) of four frozen AP were analyzed after thawing. Excellent correlations were observed between the three kits (R(2) > 0.99), for the quantification of white blood cells and total CD34. The extended kit showed considerable amounts of B-lymphoid progenitors in all CD34 sources (0-20% of all CD34 in PB, AP, and CB; 3-90% in BM). Very similar results were obtained when the same sample was prepared by different technicians. After thawing of frozen AP, the recovery of viable cells varied depending on the freezing medium employed, but the results from the different quantification methods were identical. Most non-viable cells were clearly identified with 7 Aminoactinomycin D (7AAD) but an additional gate in the forward scatter/side scatter was necessary to address dead cells negative for 7AAD. The extended SCE kit allows rapid and exact quantification of viable B-lymphoid and myeloid CD34(+) cells in all cell sources and in thawed stem cell harvests, and may thus improve the correlation between CD34 number and engraftment kinetics.

Analyses of data of patients with Thrombotic Microangiopathy in the WAA registry

Thrombotic Microangiopathy (TMA) is a histopathological feature of various diseases including thrombotic thrombocytopenic purpura and hemolytic uremic syndrome. The aim of this study was to investigate the outcome and prognostic variables of TMA-patients.

MATERIALS AND METHODS

Data were consecutively retrieved from the WAA-apheresis registry (www.waa-registry.org) during 2003-2009. Included were all 120 patients (1237 procedures) who suffered from various forms of TMA, as registered by the ICD-10 code M31.1. Besides registry data, more extensive information was retrieved from the latest 64 patients. Adverse events of the TMA patients were compared to those of the other patients in the registry.

RESULTS

The mean age was 46 years (range 11-85 years, 57% women). In 72% therapeutic apheresis was due to an acute indication while a long-term indication was present in 28%. Plasma exchange was performed by centrifugation and filtration technique (95% and 4%, respectively), and immunoadsorption in 1% of the patients. Only fresh frozen plasma was used as replacement fluid in 69% of procedures. Adverse events were more frequent than in the general apheresis population (10% versus 5%, RR 1.9, CI 1.6-2.3). No death occurred due to apheresis treatment. Three percent of the procedures were interrupted. Bronchospasm and/or anaphylactic shock were present in two patients and one patient suffered from TRALI. At admission 26% were bedridden and needed to be fed. The risk of dying during the treatment period was significantly higher if the patient also suffered from a compromising disease, such as cancer. There was an inverse correlation between the ADAMTS13 level and the antibody titer (r=-0.47, p=0.034).

CONCLUSIONS

Patients with TMA have an increased risk for moderate and severe AE compared to the general apheresis population. Many patients were severely ill at admission. The prognosis is worse if the patient also has a severe chronic disease. Even slightly increased ADAMTS13-antibody titers seem to have a negative impact on the ADAMTS13 levels.

Novel single-platform multiparameter FCM analysis of apoptosis: Significant differences between wash and no-wash procedure

FCM is a generally accepted tool to analyze apoptosis. Unfortunately, the cell preparation of all commercial kits available includes cell washing known to cause cell loss which is most likely to affect apoptotic cells in particular. To address this, we developed a seven-color single-platform no-wash analysis technique and compared the results with those from an analogous procedure including cell washing. A five-color mAb cocktail was employed to address target cells by surface labeling, Yo-PRO-1® and DAPI were used to discriminate apoptotic and necrotic from viable cells. Cells were quantified on the basis of internal-standard fluorescent beads. Jurkat cells ACC 282 treated with camptothecin were employed to establish the staining procedure, which was then applied to blood cells collected by extracorporeal apheresis and treated with UV irradiation. Data evaluation showed that although each method by itself was highly reproducible (R(2) = 0.973), the numbers of apoptotic cells detected with the no-wash procedure were significantly higher than those obtained after cell washing (P = 6.6 E(-5), Wilcoxon Test). In addition, the observed differences increased with higher cell numbers (Bland and Altmann). We conclude that the described test is a feasible and reliable tool for apoptosis measurement and it provides results that are definitely closer to the truth than those obtained from kits that require cell washing.

Training courses for pediatric apheresis on site; how apheresis technology transfer can be performed

Apheresis technology for pediatric patients and donors is still cumbersome, it is rare, mostly done in departments specialized for apheresis in adult patients, and therefore the staff is more or less anxious about dealing with especially little pediatric patients or donors. Our center is specialized in pediatrics and has a department for apheresis. We offered training courses for interested centers, which want to use the AMICUS™ system for leukapheresis in small children. In a 1-2 ay course the principles of leukapheresis in very small children were trained. To investigate the reproducibility of this training courses we invited the centers to share their data with us. As a standard we used a formula (C=[(AD):B×0.5]:1000) for predicting the CD34+ cell yield (C) by calculating the yield from total blood volume (D) processed, bodyweight (B), CD34+ cell count in peripheral blood (A) and an assumption of the collection efficiency of 50% (0.5). We hypostasized that the deviation of different centers should be in comparable limits of agreement as our own data. Thirteen centers from Germany, Poland, Ukraine, Romania, Italy, Hungary, and Slovakia asked from 1999 until today for support for pediatric leukapheresis. 6 centers sent 20 case report forms back (9 blood priming, 6 saline priming), from which 15 were completely filled in and available for the evaluation. The data were compared to 129 leukapheresis (41 blood priming, 88 saline priming) performed in our institution. The limit of agreement to the formula was -17.6% (±43) compared to -10.5% (±36). There was no statistically differences by the Mann-Whitney-U-test (p=0.5607). We conclude that training course held on site in different centers in different country could led to reproducible performance of standardized leukapheresis procedures in small children. In the future this could be a way for quality control in pediatric apheresis.

Flow cytometric monitoring of hematopoietic reconstitution in myeloablated patients following allogeneic transplantation

BACKGROUND

We report a routine flow cytometric (FACS) approach to quantify circulating leukocytes (NC) in myeloablated patients before and during regeneration after allogeneic transplantation of either whole bone marrow (BM) or of highly purified (> 99%) blood-derived CD34(+) cells (PBSC).

METHODS

Blood samples were analyzed daily between infusion of the transplant and hematopoietic reconstitution. Significant differences in the composition of NC types and CD34(+) cells were observed between the two CD34 sources. The detection threshold for NC was roughly 1 cell per w L blood.

RESULTS

The cell nadir of < 100 NC/ microL was reached on Day +4 (BM) and on day 0 (PBSC), when unusual CD34(+) cells of recipient genotype were detected in all patients. They were not clonogenic, showed high CD34 expression, but were negative for CD45, CD38, CD33, CD50, HLA-DR and Stro-1. Between Days +5 and +16, the onset of hematopoietic reconstitution was clearly detectable in multi-parameter evaluation of the FACS data. This was a median of 3.5 days before NC increased above 200/ w L blood and 4-10 days before granulocyte counts were > 500/ microL. It was marked by the appearance of monocytes, immature (CD38(+)) granulocytes, and clonogenic donor CD34(+) cells exhibited normal size and phenotype.

DISCUSSION

We conclude that dynamic FACS analyses can reliably detect hematopoietic reconstitution, but also graft rejection, before a visible increase NC numbers. This may have considerable impact on clinical management strategies.

World apheresis registry data from 2003 to 2007, the pediatric and adolescent side of the registry

OBJECTIVES

Paediatric patients are a special group in apheresis. It is general accepted to use adult indications in paediatric patients, but data in this age group are rare. In order to provide more information of apheresis practise in children and young adults (<21a) we will report of knowledge learnt by data from the registry from 2003 until 2007.

METHODS

This is a web-based registry. A link is available from the WAA homepage (www.worldapheresis.org). So far data from 12,448 procedures have been included. Six hundred and twelve procedures were performed in 135 children and young adults (308 procedures<16a, 237 from 17 to 20a, and 67 with 21a) representing 5% of the total population. The median age was 14 years (range 1-21 years), 74 male and 61 female. These data were entered by 15 centres with a frequency of in median 18 aphereses in young patients per centre (range 1-287) from 2003 to 2007.

RESULTS

Main indications: haematological diseases and also nephrological, and neurological. The type of aphereses was mainly Leukapheresis (196, 33%), plasma exchange (149, 25%), photopheresis (127, 21%), and lipid aphereses (79, 13%). Blood access: peripheral vessels in 305 procedures (50%, compared to 73% in adults), central venous catheter in 239 (38%), and AV-fistula in 2% and 0.3%, and in 8 (1.31%) procedures an arterial line was used. Anticoagulation was mostly by ACD (71%), heparin (18% or the combination of both (3%). 39 adverse events (AE) were registered in 22 (=3.59%) of the procedures, mostly graded as mild. Treatment was interrupted in 14 procedures (2.29%). AE's were abdominal pain, anaphylactic shock, flush, hyper- and hypotension, nausea, vertigo, cephalea and need for sedation and technical problems with the device and problems with the venous access. The rate of AE's was similar for stem cell harvesting and for plasma exchange (4% and 4.7%, respectively).

CONCLUSION

The paediatric data compared to the whole registry data set are showing that aphereses are performed as safe in paediatrics as in adults. Centres are mostly handling only a few cases younger than 21. Therefore more exchange of information and experience in paediatric apheresis is warranted.

Comparative evaluation of techniques for the manufacturing of dendritic cell-based cancer vaccines

Manufacturing procedures for cellular therapies are continuously improved with particular emphasis on product safety. We previously developed a dendritic cell (DC) cancer vaccine technology platform that uses clinical grade lipopolysaccharide (LPS) and interferon (IFN)-y for the maturation of monocyte derived DCs. DCs are frozen after 6 hrs exposure at a semi-mature stage (smDCs) retaining the capacity to secret interleukin (IL)-12 and thus support cytolytic T-cell responses, which is lost at full maturation. We compared closed systems for monocyte enrichment from leucocyte apheresis products from healthy individuals using plastic adherence, CD14 selection, or CD2/19 depletion with magnetic beads, or counter flow centrifugation (elutriation) using a clinical grade in comparison to a research grade culture medium for the following DC generation. We found that elutriation was superior compared to the other methods showing 36 ± 4% recovery, which was approximately 5-fold higher as the most frequently used adherence protocol (8 ± 1%), and a very good purity (92 ± 5%) of smDCs. Immune phenotype and IL-12 secretion (adherence: 1.4 ± 0.4; selection: 20 ± 0.6; depletion: 1 ±0.5; elutriation: 3.6 ± 1.5 ng/ml) as well as the potency of all DCs to stimulate T cells in an allogeneic mixed leucocyte reaction did not show statistically significant differences. Research grade and clinical grade DC culture media were equally potent and freezing did not impair the functions of smDCs. Finally, we assessed the functional capacity of DC cancer vaccines manufactured for three patients using this optimized procedure thereby demonstrating the feasibility of manufacturing DC cancer vaccines that secret IL-12 (9.4 ± 6.4 ng/ml). We conclude that significant steps were taken here towards clinical grade DC cancer vaccine manufacturing.

Compassionate use of bevacizumab (Avastin) in children and young adults with refractory or recurrent solid tumors

BACKGROUND

The aim of this study was to evaluate feasibility and toxicity of bevacizumab (Avastin), a monoclonal antibody directed against the vascular endothelial growth factor in children and young adults.

PATIENTS AND METHODS

Fifteen patients (male: n = 8; female: n = 7; median age, 14.6 years) received bevacizumab for recurrent or progressive solid tumors (carcinoma: n = 3; neuroblastoma: n = 2; astrocytoma grade III: n = 2; rhabdomyosarcoma: n = 2; nephroblastoma: n = 2; benign vascular tumors: n = 2; synovial sarcoma: n = 1; and malignant hemangiopericytoma: n = 1) on a compassionate basis. Bevacizumab was administered at 5-10 mg/kg body weight intravenously every 2-3 weeks. Most patients received chemotherapy in addition to bevacizumab. Duration of bevacizumab therapy ranged from 1.5 to 23 months.

RESULTS

Bevacizumab-related side-effects were mild and included hypertonia (n = 2), proteinuria/hematuria (n = 2), epistaxis (n = 2), local erythema (n = 1), and defective wound healing and ascites (n = 1). Radiographic objective responses (partial responses) were observed in two patients with astrocytoma grade III and in one patient each with neuroblastoma and pleomorphic rhabdomyosarcoma, respectively.

CONCLUSIONS

Bevacizumab seems to have a good acute safety profile and some antitumor activity in heavily pretreated children and young adults with recurrent solid tumors. Prospective clinical trials are urgently needed to further evaluate the safety and efficacy of bevacizumab in pediatric patients.