COVID-19 vaccine-associated immune thrombosis and thrombocytopenia (VITT): Diagnostic and therapeutic recommendations for a new syndrome

Very rare cases of thrombosis associated with thrombocytopenia have occurred following the vaccination with AstraZeneca COVID‐19 vaccine. The aim of this concise review is to summarize the current knowledge on the epidemiologic and pathogenic mechanisms of this syndrome named vaccine‐associated immune thrombosis and thrombocytopenia (VITT). A practical patient management section will also be dealt with using information available from national and international scientific societies as well as expert panels. A literature search on the VITT syndrome was carried out in PubMed using appropriate MeSH headings. Overall, 40 VITT cases have been reported. Continuous pharmacovigilance monitoring is needed to collect more data on the real incidence and the pathogenesis of VITT syndrome. Such information will also help us to optimize the management this rare but often clinically severe thrombotic condition associated with COVID‐19 vaccination.

Hemostatic therapy as a management strategy for acquired hemophilia: what does the future hold?

Introduction: Acquired hemophilia A (AHA) is a rare autoimmune disease caused by autoantibodies that bind and inactivate factor VIII (FVIII), predisposing to a potentially life-threatening bleeding.Areas covered: The main epidemiological, clinical, laboratory and therapeutic features of AHA are critically discussed. In particular, we focus on the hemostatic management of AHA patients analyzing the currently available treatment options and showing the latest data on the innovative hemostatic agents still under investigation. Authors searched the Medline and PubMed electronic databases for publication on AHA in the last twenty years.Expert opinion: While a rapid recognition of suspected cases of AHA is essential to make a correct diagnosis and appropriately and timely treat the hemorrhagic manifestations, the multidisciplinary approach to this challenging, rare and life-threatening bleeding disorder is of equal importance to improve patients' outcome. Although promising, the safety and efficacy of the clinical use of emicizumab in AHA needs to be validated by trials including an adequate number of patients, before registering the drug also for this indication.

Potential mechanisms of action of convalescent plasma in COVID-19

The COVID-19 pandemic will be remembered as one of the worst catastrophic events in human history. Unfortunately, no universally recognized effective therapeutic agents are currently available for the treatment of severe SARS-CoV-2 infection. In this context, the use of convalescent plasma from recovered COVID-19 patients has gained increasing interest thanks to the initially positive clinical reports. A number of mechanisms of action have been proposed for convalescent plasma, including direct neutralization and suppression of viremia, anti-inflammatory and immunomodulation effects and mitigation of the COVID-19-associated hypercoagulable state. These immune and non-immune mechanisms will be critically discussed in this narrative review.

Convalescent Plasma for the Treatment of Severe COVID-19

The COVID-19 pandemic in 2020 is one of the worst catastrophic events in human history. Several non-specific antiviral drugs have been tried to defeat the SARS-CoV-2, with mixed results. Convalescent plasma from patients who have recovered from COVID-19 is one of the specific biologic therapies being considered to treat SARS-CoV-2 infection. Preliminary studies have shown that convalescent plasma, containing antibodies able to neutralize SARS-CoV-2, is promising in blocking viral replication and improving patients’ clinical symptoms. The results of several ongoing randomized controlled trials are, however, keenly awaited to definitively elucidate the safety and efficacy of this blood component in COVID-19. In this narrative review, we summarize the current evidence from the literature on the treatment of severe COVID-19 with convalescent plasma. A concise overview of the hypothesized mechanisms of action is also presented.

The use of whole blood in traumatic bleeding: a systematic review

Hemostatic resuscitation is currently considered a standard of care for the management of life-threatening hemorrhage, but in some critical settings the access to high quantities of blood components is problematic. Whole blood (WB) transfusion has been proposed as an alternative modality for hemostatic resuscitation of traumatic major bleeding. To assess the efficacy and safety of WB in trauma-associated massive bleeding, we performed a systematic review of the literature. We selected studies comparing WB transfusions to transfusion of blood components (COMP) in massive trauma bleeding; both randomized clinical trial (RCT) and observational studies were considered. The outcomes were mortality (30-day/in-hospital and 24-h mortality) and adverse events/transfusion reactions. The effect sizes were crude odds ratio (OR), adjusted OR and hazard ratio (HR). The methodological quality of studies was assessed using the Cochrane Risk of Bias tool for RCTs, and the ROBIN-1 tool for observational studies. The overall quality of the available evidence was assessed with the GRADE system. One RCT (2 reports) and 6 cohort studies were included (3642 adult patients; 675 receiving WB, 2967 receiving COMP). Three studies were conducted in military setting, and 4 in civilian setting. In the overall analysis, 30-day/in-hospital and 24-h mortality did not differ significantly between groups (very low quality of the evidence due to high risk of bias, imprecision and inconsistency). After adjustment for baseline covariates in three cohort studies, the OR for mortality was significantly lower in WB recipients compared to COMP (OR 0.22; 95% CIs 0.10/0.45) (moderate grade of evidence). Adverse events and transfusion reactions were overlooked and not consistently reported. The available evidence does not allow to draw definite conclusions on the short-term and long-term efficacy and safety of WB transfusion compared to COMP transfusion. Further well designed research is needed.

A retrospective study assessing the characteristics of COVID-19 convalescent plasma donors and donations

Background

Although many trials are currently investigating the safety and efficacy of convalescent plasma (CP) in critically ill COVID‐19 patients, there is a paucity of ongoing and published studies evaluating the CP donors' side. This retrospective study reports the first Italian experience on CP donors' selection and donations.

Methods

Patients aged 18‐68 years who had recovered from COVID‐19 at least 2 weeks previously were recruited between March 18 and June 30, 2020 in a study protocol at the Italian hospitals of Pavia and Mantova.

Results

During the study period, 494 of 512 donors recruited were judged eligible and underwent 504 plasmapheresis procedures. Eighty‐five percent (437/512) of the CP donors were males. The average time between symptom recovery and CP donation was 36.6 (±20.0) days. Four hundred and eighty‐eight plasmapheresis procedures (96.8%) were concluded and each unit was divided into two subunits (total 976) with an average volume of 316.2 (±22.7) mL. Ninety‐three percent (460/494) of CP donors at the time of plasma donation had a neutralizing IgG titer ≥1:80. Plasmapheresis‐related adverse reactions occurred in 2.6% (13/504) of cases; all the reactions were mild and none required therapeutic intervention. Donors' age and COVID‐19 severity were positively associated with greater antibody responses.

Conclusion

This study demonstrates the feasibility and safety of a pilot CP program conducted in Italy. The identification of factors (ie, age and severity of COVID‐19) positively associated with higher neutralizing antibody titers at the time of donation may help to optimize the selection of CP donors.

COVID-19-associated coagulopathy

Coronavirus disease 2019 (COVID-19), a viral respiratory illness caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been recently recognized as a systemic disorder inducing a prothrombotic state. The molecular mechanisms underlying the hypercoagulable state seen in patients with COVID-19 is still incompletely understood, although it presumably involves the close link between inflammatory and hemostatic systems. The laboratory coagulation monitoring of severely ill COVID-19 patients is mandatory to identify those patients at increased thrombotic risk and to modulate thromboprophylaxis accordingly. In this review, we summarize the current understanding on the pathogenesis, epidemiology, clinical and laboratory features and management of coagulopathy associated with COVID-19.

Advances in managing rare acquired bleeding disorders

INTRODUCTION

Rare acquired bleeding disorders include a wide spectrum of coagulopathies characterized by spontaneous or post-trauma and post-surgery hemorrhages in patients without a previous personal or family history of bleeding.

AREAS COVERED

This review, based on a Medline/PubMed search during the last 20 years, will focus mainly on rare acquired bleeding disorders caused by autoantibodies against coagulation factors, including autoantibodies against factor VIII (acquired hemophilia A), von Willebrand factor (acquired von Willebrand syndrome) and other coagulation factors (factors V, X, XI, and XIII). The pathogenic, laboratory, and clinical features of these rare hemorrhagic conditions will be discussed, with particular attention to their management.

EXPERT OPINION

The treatment of rare acquired bleeding disorders includes the control of bleeding and the elimination of the autoantibody and of the underlying disease, when present. As the bleeding clinical phenotype is often severe, the management of affected patients is particularly challenging. Thus, while an early diagnosis of the acquired coagulopathy is essential to start the most appropriate treatment and to improve patients' outcomes, the support of specialized centers is equally important to provide a correct management of such complicated cases.

An early start of West Nile virus seasonal transmission: the added value of One Heath surveillance in detecting early circulation and triggering timely response in Italy, June to July 2018

In Italy, the 2018 West Nile virus transmission season started early with a high number of cases reported. One-Health surveillance, within the Italian West Nile national preparedness and response plan, detected viral circulation 9 days before symptom-onset of the first confirmed human case; triggering timely implementation of blood and transplant safety measures. This is an example of how functional coordination allows health authorities to use early warning triggers from surveillance systems to implement preventive measures.

Rare congenital bleeding disorders

The rare congenital bleeding disorders are a heterogeneous group of diseases which include deficiencies of fibrinogen, prothrombin and factors V, V + VIII, VII, X, XI and XIII. They are usually transmitted as autosomal recessive disorders, and the prevalence of the severe forms ranges from one case in 500,000 for factor VII up to one in 2,000,000 for factor XIII in the general population. Patients with rare congenital bleeding disorders may have a broad spectrum of clinical symptoms, ranging from mucocutaneous bleeding to life-threatening haemorrhages, such as those occurring in the central nervous system. The treatment of these disorders is based principally on the replacement of the deficient factor using, when available, specific plasma-derived or recombinant products. The aim of this narrative review is to summarise current knowledge about these rare bleeding conditions.

The human pegivirus: A new name for an "ancient" virus. Can transfusion medicine come up with something new?

Human pegivirus (HPgV, formerly called GB virus C/hepatitis G virus) is a poorly understood RNA virus of the Flaviviridae family. The HPgV infection is common worldwide and the virus is likely transmitted by blood products. At this time, no causal association between HPgV and human diseases has been identified. While waiting for new findings to better understand the Pegivirus genus, the aim of our narrative review is to discuss the currently available information on HPgV focusing on its prevalence in blood donors and its potential threat to transfusion safety.

Inhibitors in Patients with Congenital Bleeding Disorders Other Than Hemophilia

The most worrying complication of replacement therapy for severe hemophilia A and B is currently the occurrence of inhibitory alloantibodies against infused factor VIII and factor IX, respectively. Inhibitors compromise the management of hemorrhage in affected patients, with a considerable increase in complications, disability, and costs. While these alloantibodies have been extensively studied in the past years in hemophilia A and B, those occurring in patients with other inherited bleeding disorders are less well characterized and still poorly understood, mostly due to the rarity of these hemorrhagic conditions. This narrative review will deal with inhibitors arising in patients with inherited bleeding disorders other than "classical" hemophilia, focusing in particular on those developing in patients with congenital deficiency of coagulation factor V, factor VII, factor XI, and factor XIII.

Acquired hemophilia A: a review of recent data and new therapeutic options

OBJECTIVES

Acquired hemophilia A (AHA) is a rare, but potentially life-threatening, bleeding disorder caused by an autoantibody against factor VIII that interferes with its coagulant function.

METHODS

We performed a narrative review focusing on the diagnostic aspects of AHA and on the current treatment strategies with particular regard to new data and therapeutic developments.

RESULTS

The management of this severe hemorrhagic disorder is based on the control of bleeding with the use of bypassing agents and on the utilization of a variety of immunosuppressant agents with the goal of eliminating the autoantibody permanently.

CONCLUSION

The optimal management of AHA should be multidisciplinary and requires a close collaboration between physicians from various specialties.

The Role of ABO Blood Type in Thrombosis Scoring Systems

In addition to their major role in transfusion medicine, there is increasing evidence that ABO blood group antigens (complex carbohydrate molecules widely expressed on the surface of red blood cells and several other cell types) are implicated in the development of a wide array of pathologic conditions. In particular, intense research has been dedicated over the last 50 years to the study of the association between non-O blood type and the risk of developing cardiovascular disorders. Several pathways have been hypothesized to explain this relationship, the most reasonable implying the influence of the ABO blood group on circulating plasma levels of von Willebrand factor, factor VIII, and several inflammatory cytokines. This narrative review summarizes the current knowledge on the role of ABO antigens in both venous and arterial thromboses, focusing on their association with clinical scoring systems evaluating thrombotic risk.

International consensus statement on the peri-operative management of anaemia and iron deficiency

Despite current recommendations on the management of pre-operative anaemia, there is no pragmatic guidance for the diagnosis and management of anaemia and iron deficiency in surgical patients. A number of experienced researchers and clinicians took part in an expert workshop and developed the following consensus statement. After presentation of our own research data and local policies and procedures, appropriate relevant literature was reviewed and discussed. We developed a series of best-practice and evidence-based statements to advise on patient care with respect to anaemia and iron deficiency in the peri-operative period. These statements include: a diagnostic approach for anaemia and iron deficiency in surgical patients; identification of patients appropriate for treatment; and advice on practical management and follow-up. We urge anaesthetists and peri-operative physicians to embrace these recommendations, and hospital administrators to enable implementation of these concepts by allocating adequate resources.

West Nile Virus in Europe and Safety of Blood Transfusion

West Nile virus (WNV) has become an increasing issue in the transfusion setting since 2002, when it was firstly shown in the USA that it can be transmitted through blood transfusion. Since then, several precautionary measures have been introduced in Europe in order to reduce the possible risk of transmission via transfusion/solid organ transplantation. In addition, the epidemiological surveillance has been tightened and the network for communication of human WNV cases strengthened. This review will focus on WNV circulation and the safety of blood in Europe.

Patient blood management: a fresh look at a fresh approach to blood transfusion

The overall use of allogeneic blood transfusions in clinical practice remains relatively high and still varies widely among centres and practitioners. Moreover, allogeneic blood transfusions have historically been linked with risks and complications: some of them (e.g. transfusion reactions and transmission of pathogens) have been largely mitigated through advancements in blood banking whereas some others (e.g. immunomodulation and transfusion-related acute lung injury) appear to have more subtle etiologies and are more difficult to tackle. Furthermore, blood transfusions are costly and the supply of blood is limited. Finally, evidence indicates that a great number of the critically ill patients who are being transfused today may not be having tangible benefits from the transfusion. Patient blood management is an evidence-based, multidisciplinary, multimodal, and patient-tailored approach aimed at reducing or eliminating the need for allogeneic transfusion by managing anaemia, perioperative blood conservation, surgical haemostasis, and blood as well as plasma-derivative drug use. From this point of view, the reduction of allogeneic blood usage is not an end in itself but a tool to achieve better patient clinical outcome. This article focuses on the three-pillar matrix of patient blood management where the understanding of basic physiology and pathophysiology is at the core of evidence-based approaches to optimizing erythropoiesis, minimising bleeding and tolerating anemia. Anesthesiologists and critical care physicians clearly have a key role in patient blood management programmes are and should incorporate its principles into clinical practice-based initiatives that improve patient safety and clinical outcomes.

Human T-lymphotropic virus and transfusion safety: does one size fit all?

Human T-cell leukemia viruses (HTLV-1 and HTLV-2) are associated with a variety of human diseases, including some severe ones. Transfusion transmission of HTLV through cellular blood components is undeniable. HTLV screening of blood donations became mandatory in different countries to improve the safety of blood supplies. In Japan and Europe, most HTLV-infected donors are HTLV-1 positive, whereas in the United States a higher prevalence of HTLV-2 is reported. Many industrialized countries have also introduced universal leukoreduction of blood components, and pathogen inactivation technologies might be another effective preventive strategy, especially if and when generalized to all blood cellular products. Considering all measures available to minimize HTLV blood transmission, the question is what would be the most suitable and cost-effective strategy to ensure a high level of blood safety regarding these viruses, considering that there is no solution that can be deemed optimal for all countries.

ABO blood group: old dogma, new perspectives

Human blood group antigens are glycoproteins and glycolipids expressed on the surface of red blood cells and a variety of human tissues, including the epithelium, sensory neurons, platelets and the vascular endothelium. Accumulating evidence indicate that ABO blood type is implicated in the development of a number of human diseases, including cardiovascular and neoplastic disorders. In this review, beside its physiologic role in immunohematology and transfusion medicine, we summarize the current knowledge on the association between the ABO blood group and the risk of developing thrombotic events and cancers.

Proteomic analysis of venous thromboembolism: an update

Venous thromboembolism is a complex, multifactorial disorder, the pathogenesis of which typically involves a variety of inherited or acquired factors. The multifactorial etiology of this disease and the partial correlation between genotype and prothrombotic phenotype limit greatly the value of genetic analysis in assessing thrombotic risk. The integration of several new 'omics' techniques enables a multifaceted and holistic approach to the study of venous thrombotic processes and pave the way to the search and identification of novel blood biomarkers and/or effectors of thrombus formation that can also be the possible future target of new anticoagulant and thrombolytic therapies for more personalized medicine. This review provides a comprehensive overview of the latest candidate proteomic biomarkers of venous thrombosis and of the proteomics studies relevant to its pathophysiology, some of which seem to confirm the existence of a common physiopathological basis for venous thromboembolism and atherothrombosis.

Fast bedside measurement of blood count and C-reactive protein in newborns compared with conventional methods

BACKGROUND

Abnormal complete blood count (CBC) and high plasma C-reactive protein (CRP) are associated with neonatal infections and could be helpful in the diagnosis of neonatal sepsis and to monitor the antibiotic treatment.

OBJECTIVES

The aim of this work is to evaluate and compare the performance of a bedside analyzer for blood count and C-reactive protein (CRP) with a conventional analyzer in a neonatal population.

METHODS

150 capillary or venous blood samples of term and preterm newborns were processed on an ABX-MicrosCRP200 analyzer and on a SysmexXE2100 (conventional hematology analyzer) for CBC, leukocyte differential, reticulocytes, and nucleated red blood cells (NRBC); high-sensitivity CRP (hs-CRP) was performed on a ModularPE. The differences between complete blood count and CRP were regressed against their means and assessed by means of intra-class-correlation.

RESULTS

The intra-class-correlation for white blood cell (WBC) was 0.98, for hemoglobin 0.97, for hematocrit 0.96, for mean corpuscular volume 0.95, and for platelet 0.98. ABX-MicrosCRP200 overestimated the WBC (+1.27 x 10(3)/microL; p < 0.001), hematocrit (+1.80%; p < 0.001), and platelet (+13.55 x 10(3)/microL; p < 0.001). The intra-class-correlation for CRP was high (0.97), without systematic difference between the two values (p = 0.64).

CONCLUSIONS

The agreement between the two methods was high for both tests. However, the SD of the difference for WBC and platelet could be clinically important in leukopenic or thrombocytopenic newborns.

Blood cell counting in neonates: a comparison between a low volume micromethod and the standard laboratory method

BACKGROUND

Iatrogenic anaemia caused by repeated blood sampling to monitor laboratory parameters can contribute, particularly in neonates, to the need for transfusion. "Point of care" laboratory equipment uses smaller amounts of blood for analytic determinations and could, therefore, help to prevent secondary anaemia. In this study we compared the results of haematological parameters measured using a standard laboratory method and using a "point of care" micromethod, with the aim of validating the use of this latter method in clinical practice in neonatology.

MATERIALS AND METHODS

One hundred and fifty venous or capillary blood samples were taken from full-term or premature neonates 2-4 hours or 48 hours after birth. Each sample was processed by a standard haematology analyser and another micromethod instrument. Bland-Altman plots were constructed for each parameter and intra-class coefficients of correlation were calculated in order to evaluate the concordance between the two analysers.

RESULTS

The concordance between the data obtained with the two analysers, expressed as the intra-class correlation, was 0.98 for white blood cell count, 0.97 for haemoglobin concentration, 0.96 for haematocrit, 0.95 for mean red cell volume and 0.98 for platelet count. The micromethod produced overestimated mean values for the leucocyte count (+1.27; p<0.001), haematocrit (+1.80; p<0.001) and platelet count (+13.55; p<0.001).

CONCLUSIONS

Overall, the concordance between the values obtained with the two analysers was high for each of the parameters taken into consideration. In the case of haemoglobin and leucocytes, give the high intra-class correlation and lack of systematic overestimation of one method over another, the micromethod guarantees a correct evaluation; however, despite the high intra-class correlations for platelet counts, the systemic error seems to suggest that the micromethod cannot guarantee an appropriate evaluation of this parameter.

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.

The introduction of intra-operative cell salvage in obstetric clinical practice: a review of the available evidence

Intra-operative blood salvage is common practice in many surgical specialties but its safety is questioned with concerns about the risks of contamination of recovered blood with amniotic fluid and of maternal-foetal alloimmunization. However, the role of cell salvage as a blood-saving measure in this clinical setting is progressively acquiring relevance thanks to the growing body of evidence regarding its quality and safety. Modern cell savers remove most particulate contaminants and leukodepletion filtering of salvaged blood prior to transfusion adds further safety to this technique. Amniotic fluid embolism is no longer regarded as an embolic disease and the contamination of the salvaged blood by foetal Rh-mismatched red blood cells can be dealt with using anti-D immunoglobulin; ABO incompatibility tends to be a minor problem since ABO antigens are not fully developed at birth. Maternal alloimmunization can be caused also by other foetal red cell antigens, but it should also be noted that the risk of alloimmunization of the mother from allogeneic transfusion may be even greater. Therefore the use of cell savers in obstetric clinical practice should be considered in patients at high risk for haemorrhage or in cases where allogeneic blood transfusion is difficult or impossible.

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.