The Italian registry of therapeutic apheresis in SISTRA: Year of activity 2022

Therapeutic apheresis refers to a group of extracorporeal blood processing procedures used in the treatment of a variety of systemic diseases. These complex procedures are burdened by adverse reactions related to both procedures and underlying medical conditions. Given the importance of centralizing the collection and the analysis of information on therapeutic apheresis, the Italian National Blood Center (NBC), at the request of the Italian Scientific Society of Hemapheresis and Cell Manipulation (SIdEM), implemented the Italian Registry of Therapeutic Apheresis (IRTA) including it in the Information System of Transfusion Services (SISTRA), coordinated by the NBC. In 2022, a total of 34,702 therapeutic apheresis procedures was carried out in 8,781 patients, including paediatric patients, with an average of 3.9 procedures per patient. The 2022 IRTA data indicate that the patient with hematological and/or neurological disorders mainly turns to the apheresis centers. These results confirm the IRTA data from years 2020 and 2021. In the hematological field, the apheresis centers supply hematopoietic stem cells collection for autologous transplantation as well as mononuclear cell collection for extracorporeal photopheresis. With regard to the neurological field, myasthenia, chronic inflammatory demyelinating polyneuropathy and Guillain-Barré syndrome along with other neurological pathologies related to immune disorders are the most treated. In conclusion, this manuscript presents 2022 activity data of IRTA providing institutions and scientific societies with a wide range of information including type and number of therapeutic procedures, adverse events and patients' outcome.

Outcome of SARS CoV-2 inpatients treated with convalescent plasma: One-year of data from the Veneto region (Italy) Registry

OBJECTIVES AND BACKGROUND

Convalescent plasma (CP) has been used worldwide to contrast SARS-CoV-2 infection. Since April 2020, it has also been used in the treatment of patients with COVID-19 in the Veneto region (Italy), along with all the other available drugs and therapeutic tools. Here we report data analysis and clinical results in 1,517 COVID-19 inpatients treated with CP containing high-titre neutralizing anti-SARS-CoV-2 antibodies (CCP). Mortality after 30 days of hospitalization has been considered primary outcome, by comparing patients treated with CCP vs all COVID-19 patients admitted to hospitals of the Veneto region in a one-year period (from April 2020 to April 2021).

PATIENTS AND METHODS

Adult inpatients with a severe form of COVID-19 have been enrolled, with at least one of the following inclusion criteria: 1) tachypnea with respiratory rate (RR) ≥ 30 breaths/min; 2) oxygen saturation (SpO₂) ≤ 93% at rest and in room air; 3) partial pressure of oxygen (PaO₂)/fraction of inspired oxygen (FiO₂) ≤ 200 mmHg, 4) radiological picture and/or chest CT scan showing signs of interstitial disease and/or rapid progression of lung involvement. Patients received a maximum of three therapeutic fractions (TFs) of CCP with a neutralizing antibody titre of ≥ 1:160, administered over a period of 3-5 days. If TFs of CCP with titre ≥ 1:160 were unavailable, 2 with antibody titre of ≥ 1:80 have been administered.

RESULTS

Of the 1,517 patients treated with CCP, 209 deceased at the 30-day follow-up (14%). Death was significantly associated with an older age (p<0.001), a longer time of hospitalization before CCP infusion (p<0.001), a greater number of inclusion criteria (p<0.001) and associated comorbidities (p<0.001). Conditions significantly associated with an increased frequency of death were PaO₂/FiO₂ ≤ 200 (p<0.001) and tachypnea with RR>30 (p<0.05) at entry, concurrent arterial hypertension (p<0.001), cardiovascular disease (p<0.001), chronic kidney disease (p<0.001), dyslipidemia (p<0.05) and cancer (p<0.05). Moreover, factors leading to an unfavorable prognosis were a life-threatening disease (p<0.001), admission to Intensive Care Unit (p<0.001), high flow oxygen therapy or mechanical ventilation (p<0.05) and a chest X-ray showing consolidation area (p<0.001). By analyzing the regional report of hospitalized patients, a comparison of mortality by age group, with respect to our series of patients treated with CCP, has been made. Mortality was altogether lower in patients treated with CCP (14% v. 25%), especially in the group of the elderly patients (23% vs 40%,), with a strong significance (p<0.001). As regards the safety of CCP administration, 16 adverse events were recorded out of a total of 3,937 transfused TFs (0,4%).

CONCLUSIONS

To overcome the difficulties of setting up a randomized controlled study in an emergency period, a data collection from a large series of patients with severe COVID-19 admitted to CCP therapy with well-defined inclusion criteria has been implemented in the Veneto region. Our results have shown that in patients with severe COVID-19 early treatment with CCP might contribute to a favourable outcome, with a reduced mortality, in absence of relevant adverse events.

Neutralizing Antibody Responses to SARS-CoV-2 in Recovered COVID-19 Patients Are Variable and Correlate With Disease Severity and Receptor-Binding Domain Recognition

Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) caused outbreaks of the pandemic starting from the end of 2019 and, despite ongoing vaccination campaigns, still influences health services and economic factors globally. Understanding immune protection elicited by natural infection is of critical importance for public health policy. This knowledge is instrumental to set scientific parameters for the release of “immunity pass” adopted with different criteria across Europe and other countries and to provide guidelines for the vaccination of COVID-19 recovered patients. Here, we characterized the humoral response triggered by SARS-CoV-2 natural infection by analyzing serum samples from 94 COVID-19 convalescent patients with three serological platforms, including live virus neutralization, pseudovirus neutralization, and ELISA. We found that neutralization potency varies greatly across individuals, is significantly higher in severe patients compared with mild ones, and correlates with both Spike and receptor-binding domain (RBD) recognition. We also show that RBD-targeting antibodies consistently represent only a modest proportion of Spike-specific IgG, suggesting broad specificity of the humoral response in naturally infected individuals. Collectively, this study contributes to the characterization of the humoral immune response in the context of natural SARS-CoV-2 infection, highlighting its variability in terms of neutralization activity, with implications for immune protection in COVID-19 recovered patients.

Acute pancreatitis due to severe hypertriglyceridemia in the COVID-19 era: The role of therapeutic plasma exchange

The psychosocial consequences of the COVID-19 pandemic caused multifaceted challenges in clinical and therapeutic practices. This was the case at the Therapeutic Apheresis Unit of the Padua University Hospital too. Several published reports describe the increase in alcohol and food addiction diseases. In this context, during the last months, the Padua Therapeutic Apheresis Unit treated many more patients with acute pancreatitis due to severe hypertriglyceridemia with therapeutic plasma exchange than in the previous ten years. Furthermore, retrospective cohort studies have been recently published describing the onset of acute pancreatitis during the COVID-19 infection even if, to date, there is still insufficient evidence to estabilish a direct causality. Anyway, the COVID-19 pandemic translated into changes of the overall disease prevalence scenario and therefore the Padua Therapeutic Apheresis Unit will need to reorganise its Therapeutic Apheresis activity.

Preparedness and activities of the anti-SARS-CoV-2 convalescent plasma bank in the Veneto region (Italy): An organizational model for future emergencies

Background

Convalescent plasma (CP) has been used in the past in various pandemics, in particular in H1N1, SARS and MERS infections. In Spring 2020, when ongoing the SARS-CoV-2 pandemics, the Veneto Region (V-R) has proposed setting-up an anti-SARS-CoV-2 CP (CCP) Bank, with the aim of preparing a supply of CCP immediately available in case of subsequest epidemic waves.

Materials and Methods

Key-points to be developed for a quick set-up of the V-R CCP Bank have been recruitment of donors recovered from COVID-19 infection, laboratory analysis for the biological qualification of the CCP units, including titre of neutralizing antibodies and reduction of pathogens, according to National Blood Centre (CNS) Directives, adaptation of the V-R Information Technology systems and cost analysis. Some activities, including diagnostic and viral inactivation processes, have been centralized in 2 or 3 sites. Laboratory analysis upon preliminary admission of the donor included all tests required by the Italian laws and the CNS directives.

Results

From April to August 2020, 3,298 people have contacted the V-R Blood Transfusion Services: of these, 1,632 have been evaluated and examined as first time donors and those found to be suitable have carried out 955 donations, from which 2,626 therapeutic fractions have been obtained, at a cost around 215,00 Euro. Since October 2020, the number of COVID-19 inpatients has had a surge with a heavy hospital overload. Moreover, the high request of CCP therapy by clinicians has been just as unexpected, showing a wide therapeutic use.

Conclusions

The organizational model here presented, which has allowed the rapid collection of a large amount of CCP, could be useful when facing new pandemic outbreaks, especially in low and middle income countries, with generally acceptable costs.

IgG Antibody Responses to the Aedes albopictus 34k2 Salivary Protein as Novel Candidate Marker of Human Exposure to the Tiger Mosquito

Mosquitoes of the Aedes genus transmit arboviruses of great importance to human health as dengue, chikungunya, Zika and yellow fever. The tiger mosquito Aedes albopictus can play an important role as arboviral vector, especially when Aedes aegypti is absent or present at low levels. Remarkably, the rapid worldwide spreading of the tiger mosquito is expanding the risk of arboviral transmission also to temperate areas, and the autochthonous cases of chikungunya, dengue and Zika in Europe emphasize the need for improved monitoring and control. Proteomic and transcriptomic studies on blood feeding arthropod salivary proteins paved the way toward the exploitation of genus-specific mosquito salivary proteins for the development of novel tools to evaluate human exposure to mosquito bites. We previously found that the culicine-specific 34k2 salivary protein from Ae. albopictus (al34k2) evokes specific IgG responses in experimentally exposed mice, and provided preliminary evidence of its immunogenicity to humans. In this study we measured IgG responses to al34k2 and to Ae. albopictus salivary gland protein extracts (SGE) in individuals naturally exposed to the tiger mosquito. Sera were collected in two areas of Northeast Italy (Padova and Belluno) during two different time periods: at the end of the low- and shortly after the high-density mosquito seasons. Anti-SGE and anti-al34k2 IgG levels increased after the summer period of exposure to mosquito bites and were higher in Padova as compared to Belluno. An age-dependent decrease of anti-saliva IgG responses was found especially in Padova, an area with at least 25 years history of Ae. albopictus colonization. Moreover, a weak correlation between anti-saliva IgG levels and individual perception of mosquito bites by study participants was found. Finally, determination of anti-al34k2 IgG1 and IgG4 levels indicated a large predominance of IgG1 antibodies. Overall, this study provides a convincing indication that antibody responses to al34k2 may be regarded as a reliable candidate marker to detect temporal and/or spatial variation of human exposure to Ae. albopictus; a serological tool of this kind may prove useful both for epidemiological studies and to estimate the effectiveness of anti-vectorial measures.

PTH: Redefining Reference Ranges in a Healthy Population-The Role of Interfering Factors and the Type of Laboratory Assay

Introduction. Parathyroid hormone (PTH) is a linear peptide constituted by 84 amino acids and active in its 1-84 form, but a wide range of PTH forms produced by its post-transcriptional modifications are present in blood. Many assays with different specificities are commercially available. The aim of our study was to compare a 2^nd and 3^rd generation in healthy population in order to better define the reference range in the healthy population residing in our region. Materials and Methods. 108 subjects (53 females and 55 males) referring to the transfusion donor were enrolled in the study centre in April 2016 and underwent PTH levels measurements with a 3^rd generation kit (chemiluminescent immunoassay DiaSorin Liaison) and with a 2^nd generation kit (immunoradiometric assay Total Intact PTH Assay (Coated Tube), Scantibodies). Also calcium, phosphate, creatinine, and 25OHD3 were measured. A questionnaire on lifestyle and dietary habits was obtained.

RESULTS

The median PTH values obtained with the 2^nd generation assay and the whole 3^rd generation assay were 20.26 pg/ml and 23.11 pg/ml, respectively. Bland-Altman method showed substantial concordance between the two PTH assays, although with an overestimation of the 3^rd generation method over the 2^nd generation method. There was no correlation between 3^rd generation PTH and 25OHD3 and creatinine. Calcium was negatively correlated with PTH only when measured with 3^rd generation kit.

CONCLUSIONS

On the basis of our data, obtained from healthy subjects, we can conclude that the reference range used by our laboratory was too narrow and was necessary to reestablish normal ranges according to our population. This is useful to avoid hyperparathyroidism misdiagnosis.

Therapeutic apheresis during pregnancy: A single center experience

INTRODUCTION

Therapeutic apheresis (TA) represents a treatment option for pre-existing conditions or diseases occurring during gestation. Although pregnancy is not a contraindication per se, due to the lack of evidence-based guidelines and presumed risk of maternal/fetal adverse events there is a general resistance to its application.

MATERIAL AND METHODS

Between January 2005 and August 2017, at the Apheresis Unit of the University Hospital of Padua 936 TA procedures were performed during 57 pregnancies in 48 patients: 813 Plasma Exchange sessions, 119 Immunoadsorptions, 4 Red Blood Cell exchanges. The treated disease were as follows: antiphospholipid syndrome (18 patients), autoimmune congenital heart block (18), myasthenia gravis (3), Rh alloimmunization (2), systemic sclerosis (1), suspected autoimmune encephalitis (1), severe hypertriglyceridaemia (1), post partum hemolytic-uremic syndrome (1), sickle cell disease (1), lupus nephritis (1) and thrombotic thrombocytopenic purpura (1).

RESULTS

In the time period considered the apheresis sessions applied to pregnant women were 7.1% of the total (n = 13.251). The median age at the first treatment was 33 years. The median week of gestation (WG) at the beginning of treatments was 21. Twenty (2.1%) sessions were complicated by adverse events, none requiring or prolonging hospitalization. There were 50 live births, 5 spontaneous abortions and 2 voluntary terminations of pregnancy. Median WG at delivery was 35 and caesarean section was performed in 46 cases.

CONCLUSIONS

Our data showed that TA in pregnancy is well tolerated. Close collaboration between clinician, obstetrician and TA specialist is crucial to ensure a good outcome of high-risk pregnancies.

Plasma-derived industry and plasma-derived medicinal products in the Italian National Blood Transfusion Service

The priority objectives of the Italian Transfusion System are self-sufficiency for blood components and for plasma-derived products. Currently the collection activity guarantees self-sufficiency of blood components, including plasma for clinical use, but not for plasma-derived drugs, ie albumin and immunoglobulins in particular. The National Plasma Program of 2016-2020, issued a Ministerial Decree on December, 2, 2016, aims to achieve this goal, both by increasing the collection of plasma and therefore its transfer to plasma derivation companies, and by increasing the appropriateness of the requests. Currently, the companies Grifols SpA, Kedrion SpA, CSL Behring, and Baxter-Baxalta Srl are present on the Italian market, individually or in business associations, with which the various Italian regions have established an agreement based on the national legislation.

Genetic history of the population of Crete

The medieval history of several populations often suffers from scarcity of contemporary records resulting in contradictory and sometimes biased interpretations by historians. This is the situation with the population of the island of Crete, which remained relatively undisturbed until the Middle Ages when multiple wars, invasions, and occupations by foreigners took place. Historians have considered the effects of the occupation of Crete by the Arabs (in the 9th and 10th centuries C.E.) and the Venetians (in the 13th to the 17th centuries C.E.) to the local population. To obtain insights on such effects from a genetic perspective, we studied representative samples from 17 Cretan districts using the Illumina 1 million or 2.5 million arrays and compared the Cretans to the populations of origin of the medieval conquerors and settlers. Highlights of our findings include (1) small genetic contributions from the Arab occupation to the extant Cretan population, (2) low genetic contribution of the Venetians to the extant Cretan population, and (3) evidence of a genetic relationship among the Cretans and Central, Northern, and Eastern Europeans, which could be explained by the settlement in the island of northern origin tribes during the medieval period. Our results show how the interaction between genetics and the historical record can help shed light on the historical record.

Peripheral imbalanced TFH/TFR ratio correlates with intrathecal IgG synthesis in multiple sclerosis at clinical onset

BACKGROUND

Alteration of T-follicular helper (TFH) and regulatory (TFR) subpopulations may contribute to the development of auto-reactive B-cell.

OBJECTIVE

To investigate whether changes in TFH and TFR subsets are associated with abnormal IgG synthesis in blood and cerebrospinal fluid (CSF) of multiple sclerosis (MS) patients.

METHODS

Paired blood and CSF samples were obtained from 31 untreated relapsing-remitting multiple sclerosis (RRMS) patients at diagnosis. Peripheral blood TFH (CD3+CD4+CXCR5+CD25-CD127+), TFR (CD3+CD4+CXCR5+CD25+CD127^dim), conventional T-Helper (TH, CD3+CD4+CXCR5-CD25-CD127+), and regulatory T-cells (T-Reg, CD3+CD4+CXCR5-CD25+CD127^dim) were analyzed in all RRMS patients and in 13 healthy controls (HCs). Qualitative and quantitative intrathecal IgG synthesis was evaluated in RRMS patients, who were then further subclassified according to the presence of IgG oligoclonal bands in blood and/or CSF.

RESULTS

Compared to HC, RRMS had lower TFR percentage ( p < 0.01) and higher TFH/TFR ratio ( p < 0.001). In RRMS, TFH/TFR ratio correlated with both qualitative ( r = 0.56, p < 0.005) and quantitative intrathecal IgG synthesis (IgG Index: r = 0.78; IgGLoc: r = 0.79; IgGIF: r = 0.76, all p < 0.001). Patients with the highest TFH/TFR ratios had higher percentages of circulating B-cells (36.1 ± 35.2%, p < 0.05).

CONCLUSION

In RRMS, increased TFH/TFR ratio associates with abnormal IgG production in blood and CSF, suggesting that antibody-producing cells, derived from deregulated peripheral germinal center reaction, colonize the CNS.

The mechanisms of rejection in solid organ transplantation

Organ transplantation represents the preferred treatment option for many patients in terminal organ failure. The half-life of transplanted organs, however, is still far from being satisfactory with the vast majority of the organs failing within the first two decades following transplantation. At this stage, it has become apparent that rejection (prevalently mediated by humoral events) remains the primary cause of graft loss after the first year. In this light, studies are underway to better comprehend the immune events underlying graft rejection and novel immunosuppressive strategies are being explored. In this context, therapeutic apheresis techniques, that include therapeutic plasma exchange (TPE), immunoadsorption (IA) and extracorporeal photochemotherapy (ECP), represent an important adjunct in the current immunosuppressive armamentarium. This article briefly reviews our current understanding of the immune process underlying rejection of a solid organ transplant and describes the principal areas of application of therapeutic apheresis techniques in transplantation.

Therapeutic apheresis in pregnancy: General considerations and current practice

It is widely known that pregnancy does not represent a contraindication to therapeutic apheresis (TA) techniques. In fact, since the first experiences of TA in pregnancy for the prevention of hemolytic disease of the newborn, several diseases are at present treated with TA, mainly within 6 clinical categories: (a) TA is a priority and has no alternative equally effective treatment (e.g., thrombotic thrombocytopenic purpura); (b) TA is a priority but there are alternative therapies not contraindicated in pregnancy (e.g., myasthenia gravis); (c) TA is an effective tool of saving/avoiding drugs contraindicated in pregnancy (e.g., systemic lupus erythematosus); (d) TA is a treatment of specific conditions/complications of pregnancy with maternal and/or fetal risk (e.g., antiphospholipid syndrome); (e) TA is a treatment of specific conditions of pregnancy with exclusive fetal risk (e.g., hemolytic disease of the newborn); (f) TA is a treatment of disease which is strongly indicated and can exceptionally occur during pregnancy (e.g., Goodpasture's syndrome). When dealing with TA pregnant patients, some technical aspects due to the physiological changes of gestation have to be carefully considered, in particular the increase of the circulating blood volume. Moreover a multidisciplinary medical team, including an obstetrician, a clinical consultant, specialist in TA and in transfusion medicine, and a neonatologist stand as a basic requirement for the proper management of some clinical conditions that may be characterized by high maternal and fetal risk.

Treatment of Acute Graft-versus-Host Disease in Childhood with Extracorporeal Photochemotherapy/Photopheresis: The Padova Experience

Acute graft-versus-host disease (aGVHD) is the major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation. Systemic steroid treatment represents the first-line therapy for aGVHD and is associated with a response rate of 30% to 60%. Steroid-resistant patients have a poor prognosis with high transplantation-related mortality (TRM). Several second-line therapies have been proposed for the management of unresponsive aGVHD, without proven beneficial effects on patients' outcome or overall long-term survival. For these reasons, extracorporeal photochemotherapy/photopheresis (ECP), a cell-based approach to control GVHD that spares generalized immunosuppression, seems to be promising. In this study, we report the outcome of 72 consecutive pediatric patients treated with ECP between 1997 and 2013 for aGVHD. Among them, 21 patients had steroid-resistant aGVHD, 42 had steroid-dependent aGVHD, and 9 did not receive steroid as first-line therapy because of clinical contraindications. A complete response was obtained in 72% of patients, a partial response was observed in 11%, and there was no response in 17% of patients. At day +180, TRM was 4% in the whole cohort; TRM was 3% and 20% among responders and nonresponders to ECP, respectively (P < .0001). The 5-year overall survival was 71%, showing a difference between responders and nonresponders of 78% and 30%, respectively (P = .0004). The 5-year time to progression of primary disease was 81%, without any significant difference between the 2 groups. Moreover, the 5-year progression-free survival of primary disease was 72%, with a significant difference (P = .0007) between responders (79%) and nonresponders (30%) to ECP. In conclusion, this study demonstrates that ECP is highly effective in aGVHD without a negative impact on primary disease.

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We conducted a retrospective study of 72 consecutive pediatric patients treated with extracorporeal photochemotherapy/photopheresis for acute graft-versus-host disease.

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Twenty-one steroid-refractory, 21 steroid-dependent, and 30 patients with infectious complications were included.

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The infectious complications group included 9 with no steroids before extracorporeal photochemotherapy/photopheresis and 21 with steroids.

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Outcomes at the end of extracorporeal photochemotherapy/photopheresis were complete remission, 72%; transplantation-related mortality day +180, 4%; 5-year overall survival, 71%; time to progression, 81%; and progression-free survival, 72%.

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Extracorporeal photochemotherapy/photopheresis was highly effective in acute graft-versus-host disease without negative impact on primary disease.

Stress, burnout, and job satisfaction in 470 health professionals in 98 apheresis units in Italy: A SIdEM collaborative study

AIMS

In Italian and international background, there are no studies focusing on stress, burnout indicators, and job satisfaction in health professionals working in the apheresis units. This study aims to fill this void both for scientific and clinical reasons.

METHODS

The participants were 470 health professionals (220 physicians, 250 nurses), mostly female (73.4%), with an average age of 48.09 (with the 5° percentile under 32 years and the 95° percentile over 60), working in the Apheresis Units in the North (228), in the Center (131) and in the Southern-islands of Italy (111). The health professionals' years on the job were principally between one and 10 years (40.2%) or from 11 to 20 years (33.2%). The prevalent activity was therapeutic apheresis (48.5%). The self-report questionnaires were proposed electronically by a protected online site.

RESULTS

Important stress levels were identified in the health professionals. Physicians principally showed medium (47.5%) and high (35.8%) stress levels. Stress levels of nurses were mostly low (57.7%) or medium (25.7%). Female gender in nurses [t(268) = -3.29; P = 0.001] and in physician professions [t(217) = -3.01; P = 0.03] was a risk factor for stress. Both job categories were placed at a high risk level for burnout syndrome comparing with normative scales, especially the health professionals working in the center of Italy for the scales "Emotional exhaustion" [F(2) = 4.39; P = 0.013] and "Professional inefficacy" [F(2) = 4.38; P = 0.013].

CONCLUSIONS

Health professionals working in the apheresis unit show high stress levels and burnout risk. New preventive programs and specific clinical interventions should be constructed.

[Use of virus-inactivated plasma in apheresis treatment of thrombotic thrombocytopenic purpura: preliminary data]

Plasma exchange (TPEx) with fresh frozen plasma (FFP) or cryosupernatant plasma infusion is the treatment of choice for thrombotic thrombocytopenic purpura (TTP). The authors evaluate the preliminary data of the multicenter SIdEM study that compares virus-inactivated plasma with fresh frozen plasma (FFP) or cryosupernatant plasma in the apheretic treatment of TTP.

[Apheresis in antiphospholipid syndrome (APS)]

Antiphospholipid syndrome (APS) is a rare clinical disorder characterized by thromboembolic manifestations and/or obstetric complications. Along with the clinical symptoms and signs, serum antiphospholipid antibodies have to be detected. APS can be primary, i.e., without any concomitant disorders, or secondary to other autoimmune diseases, particularly systemic lupus erythematosus. Criteria for the diagnosis of APS have been clearly established. Hyperacute APS (or catastrophic antiphospholipid syndrome), often with a poor prognosis, must meet four criteria: involvement of three or more organs, rapid evolution of clinical manifestations, microangiopathic occlusion of small blood vessels at biopsy, and presence of antiphospholipid antibodies. The rationale for apheresis treatment is the removal of pathogenetic antibodies involved in the development of tissue damage. Our experience includes 23 patients, in particular 15 women treated for 19 pregnancies. According to the National Guidelines Program, the effectiveness of apheresis in catastrophic syndrome has a level of evidence of V/VI, with a strength of recommendation A; in highrisk pregnancy it has a level of evidence of V with a strength of recommendation B. It will be necessary to better define the prognosis of various categories of pregnant patients with APS, as well as useful laboratory parameters to monitor its clinical course and anticipate any complications of pregnancy.

Therapeutic plasma exchange in patients with severe hypertriglyceridemia: a multicenter study

Extremely high plasma triglyceride (TG) concentration is a recognized risk factor for acute pancreatitis (AP). In order to evaluate the therapeutic efficacy of plasma-exchange plasmapheresis in treating patients with severe hypertriglyceridemia (sHTG), 17 patients who had not responded to conventional medical therapy (fat-free diet plus pharmaceutical interventions) were referred for therapeutic plasma exchange (TPE) in a multicenter frame case series study. Two hundred seventeen TPE sessions were performed, and therapy is ongoing for five (30%) of the patients. After treatment, the mean plasma TG and total cholesterol concentrations were significantly reduced from 1929 and 510 mg/dL, to 762 and 227 mg/dL, respectively (P < or = 0.001 in both cases). In most cases, the interval between treatments was related to the clinical presentation and individual circumstances. The removal of TG-rich lipoproteins prevented relapses of AP. In this case series, TPE is confirmed as a safe and reliable method for treating patients with refractory sHTG when a severe complication, such as AP, is clinically demonstrated or can be actively prevented. Therefore, in cases where standard medical approaches fail to promote the clearance of TGs from plasma and a high risk of first or second hypertriglyceridemic pancreatitis persists, TPE provides a therapeutic option for preventing life-threatening sHTG.

Study of the microcirculation in hDAF transgenic rat livers xenoperfused with human blood

BACKGROUND

The microcirculation was assessed in the livers of human decay accelerating factors (hDAF) and wild-type transgenic rats by fluorescent intravital microscopy, histology and histomorphology to determine the benefits of hDAF expression for the microcirculation of a rat liver xenograft perfused with human blood.

METHODS

Male hDAF transgenic rats (group A; n = 20) and wild-type Sprague-Dawley rats (group B; n = 20) were xenoperfused with human blood, while other male wild-type Sprague-Dawley rats (group C; n = 10) were perfused with allogeneic blood. Following plasma and leukocyte staining with fluorescein sodium, and platelet staining with rhodamine, the right lobe of the liver was assessed by intravital microscopy, counting the numbers of perfused sinusoids and leukocytes adhering to the endothelium per mm(2), and calculating the acinar perfusion index (Pi). The liver underwent histological assessment at the end of each experiment. Mean +/- SEM values were calculated and the Mann-Whitney U-test was used for statistical analysis.

RESULTS

The number of perfused sinusoids was higher in the group of hDAF rat livers (group A) and controls (group C) than in the group of non-transgenic rat livers perfused with human blood (group B) (P < 0.05), although only group C still had a significantly more perfused sinusoids than the other groups after 90 min of perfusion (P < 0.05). The acinar perfusion index was higher in groups A and C than in group B (P < 0.05); here again, only group C still had a significantly higher Pi than group B after 90 min of perfusion (P < 0.05). There was a massive accumulation of leukocytes that peaked after 5 min and persisted throughout the perfusion in all three groups. Histology showed portal and subendothelial hepatic vein hemorrhage, necrosis and inflammatory reaction, which were particularly evident in group B.

CONCLUSION

In our study, rat livers transgenic for hDAF were better protected against early tissue damage by perfusion with human blood, but this did not result in a longer xenograft survival.

ABO-incompatible heart transplantation: crossing the immunological barrier

Due to the shortage of organ donors, heart transplantation cannot be offered to many infants with end-stage heart failure; this issue leads to mortality rates of 30-50% in patients in the paediatric age group awaiting operation. ABO-incompatible heart transplantation has been performed safely with no particular or invasive preparatory procedures other than plasma exchange during cardiopulmonary bypass for removing preformed antibodies, with no reports of hyperacute rejection. We report our first clinical experience of heart transplantation on a 2-month-old-infant (blood group O), diagnosed with intracardiac tumour, in which the donor was a 19-day-old newborn of blood group A. Sharing the know-how about ABO-incompatible heart transplantation in newborns and infants awaiting transplantation will help in decreasing mortality among this group of patients.

Reduced mobilisation of hematopoietic stem cells after hepatic resection for malignant liver disease

Recent studies have demonstrated that hematopoietic stem cells (HSCs) can mobilize following liver resection, thus contributing to the repair of hepatic damage. Aim of this study has been to determine whether the nature of the hepatic lesion (benign vs. malignant disease) can give rise to a different degree of mobilisation of HSCs. Two groups of patients were selected: the first included seven patients undergoing hepatic resection (five major and two minor) for a benign liver disease (focal nodular hyperplasia, hemangioma cavernosa, angioma, biliary adenofibroma) and the second included seven patients undergoing hepatic resection (five major and two minor) for a malignant (either primary or secondary) liver disease. White blood cell count and CD34+ (percentage and total number) at time T(0) (basal value before surgery) and at time T(1) (value on the sixth-eighth day after surgery) have been evaluated by standard methods. In the group undergoing hepatic resection for a benign liver disease, a significant increase of CD34+ cells, both in percentage (0.082 +/- 0.043 vs. 0.048 +/- 0,026, p = 0.041) and in absolute number (8.14 +/- 5.95 vs. 3.26 +/- 2.63, p = 0.018) have been documented, as opposed to the group of patients affected with a malignant liver disease, where no significant variation has been observed (CD34+ %: 0.044 +/- 0.033 vs. 0.041 +/- 0.031, p: n.s.; CD34+ total number: 3.52 +/- 2.56 vs. 2.27 +/- 2.01, p = n.s.) These results show a different bone marrow response to the surgical liver resection depending on the nature of the lesion, thus emphasizing a reduced mobilisation of HSCs in the malignant diseases. Since it has been documented that the type of the hepatic lesion can induce a different regenerative response, it has to be explained how the neoplastic lesions can negatively influence the mobilization of HSCs. It can be hypothesized that a variety of humoral factors, including stromal cell-derived factor, matrix metalloproteinases, hepatocyte growth factor and interleukin-8 can influence the process of mobilization of HSCs after liver resection surgery. These substances are also involved in the mechanisms of development and metastasising of many tumours. It is probably in this context that a reason may be found for the different mobilisation of hematopoietic stem cells, depending on the nature of the hepatic lesion treated, that was encountered in this study.

Mobilization of peripheral blood hematopoietic stem cells following liver resection surgery

BACKGROUND/AIMS

Stem cells are characterized by plasticity, namely the ability of interchanging between various tissue and organs. In this regard, many studies have demonstrated the presence of antigenic structures relevant to the hematopoietic stem cell on hepatocytes, thus suggesting that in certain conditions liver cells may derive from the hematopoietic compartment. The aim of this study has been to verify whether surgical liver resection can activate bone marrow, by mobilizing peripheral blood hematopoietic stem cells (CD34+ cells) putatively able to induce liver repopulation.

METHODOLOGY

White blood cell and CD34+ cell count was determined at baseline (before surgery) and then monitored in the postoperative period in 13 patients undergoing liver resection (in most cases because of malignant, primary or secondary liver diseases) and, as a control group, in 12 patients affected with other diseases requiring abdominal surgery, but not liver resection. Moreover, to assess the basal value of circulating CD34+ cells, 50 healthy blood donors were included in the study. The CD34+ cell count has been carried out by flow cytometry, by applying conventional protocols.

RESULTS

Patients, as altogether considered, showed at baseline a significantly higher white blood cell count as compared to healthy controls (7.41+/-2.89 x 10(3)/microL vs. 6.00+/-1.37 x 10(3)/microL, P<0.01), as opposed to the CD34+ cell count, the results of which were significantly lower (2.8+/-1.8/microL vs. 4.1+/-1.9/microL, P<0.01). The increase of CD34+ cells was significantly higher in patients following liver resection as compared to others (+6.5+/-4.1/microL vs. +0.7+/-1.4/microL, P<0.001), whereas the variation of white blood cell count was not statistically significant (+1.87+/-3.76 x 10(3)/microL vs. + 1.51+/-2.87 x 10(3)/microL).

CONCLUSIONS

Our results indicate that hepatic injury caused by extensive liver resection may constitute a trigger to the mobilization of hematopoietic stem cells putatively able to differentiate into hepatocytes, thus starting the recovery process of liver. These data could open innovative views to the treatment of certain liver diseases (e.g. fulminant hepatic failure), in particular by the administration of hematopoietic growth factors, such as G-CSF or GM-CSF, after the hepatic damage, to contribute, through the activation of the hematopoietic compartment, to a more efficient liver regeneration.

National survey of apheresis activity in Italy (2000)

Data collection on apheresis in Italy throughout 2000, including techniques, machines, clinical indications and adverse effects, has been performed by means of a standardized questionnaire. These data provided from 102 Apheresis Units from 19 Italian regions, albeit rough, are sufficiently informative. In 2000 a total number of 164,943 apheresis procedures has been carried out, with a clear-cut prevalence of productive apheresis (90.8%), that has been performed by all Apheresis Units. Lombardy, Venetia and Liguria have been the most active regions for therapeutic apheresis (54.0% of the total activity). Adverse events, predominantly mild ones (i.e., paresthesia due to citrate-induced hypocalcemia) have occurred in 0.59% of productive and in 6.75% of therapeutic apheresis sessions, particularly in the course of peripheral blood stem cell collection (13.0%).

Hepatocyte transplantation in the treatment of acute liver failure: microencapsulated hepatocytes versus hepatocytes attached to an autologous biomatrix

A liver transplant is considered today to be the only effective therapeutic solution for many otherwise intractable hepatic disorders. However, liver transplantation is beset by shortage of donors. Over the years, many liver support systems have been developed to supply the liver functions, mostly as a bridge to transplantation. Transplantation of isolated hepatocytes (HcTx) instead of whole liver has constituted one of the most appealing possibilities to treat several diseases. We compared two different models of HcTx in a surgical model of acute liver failure in pigs, using microencapsulated hepatocytes (MHcTx) and hepatocytes attached to a porcine biomatrix (PBMHcTx), both transplanted into peritoneum. The collected data were survival, laboratory findings, hemodynamic parameters, light microscopy, histology, MTT, and glycogen content. The group with PBMHcTx has a better outcome than the group with MHcTx (p < 0.05). Histology showed normal morphology of the hepatocytes, high glycogen content, 75% viability, positive MTT, and 95% adhesion of the hepatocytes to the biomatrix. Our biomatrix (PBM) provides cell-to-cell contact and interaction with extracellular matrix, which have been shown to play major roles in hepatocyte survival and physiologic regulation of gene expression, and guarantee a prompt engraftment and an adequate neovascularization. PBMHcTx is a useful method to treat acute liver failure and it indicates a possible liver-direct gene therapy in the treatment of inherited and acquired disorders.

Granulocyte transfusions from G-CSF-stimulated donors for the treatment of severe infections in neutropenic pediatric patients with onco-hematological diseases

From March 1994 to January 2001, 15 courses of granulocyte transfusion (GTX) were administered to 13 neutropenic patients (6 male and 7 female patients; median age 7 years, range 3 months to 14 years) affected by: acute lymphoblastic leukemia (ALL) in 6 cases, acute myeloid leukemia (AML) in 5, very severe aplastic anemia in 1, and familial erythrophagocytic lymphohistiocytosis (FEL) in 1. Infections were classified as microbiologically defined and clinically defined infections in 8 and 7 episodes, respectively. Before the GTX transfusions, broad-spectrum antibacterial and antifungal therapy had been administered for a median of 12 (range 5-28) and 8 days (range 2-50), respectively, with no improvement. G-CSF was administered prior to GTX in 9 episodes of infection, with a median of 9 days of treatment (range 4-30). Leukapheresis was obtained from 15 related donors (father, 10; mother, 3; sister, 1; aunt, 1) after s.c. stimulation with G-CSF, 300 micro g daily, starting from day -3 (where day 0 was the day of the first granulocyte collection) and continuing throughout the period of GTX treatment. The donors' median white blood cell (WBC) count at leukapheresis was 31.6 x 10(9)/l (range 12-56), and the median yield was 31.39 x 10(9) WBC (range 2.96-64.73 x 10(9)), with a proportion of PMN of 90-95%. Overall, 70 GTX were administered, with a median of 4 GTX per episode of infection (range 2-11). The combination of GTX with antimicrobial therapy led to complete or partial recovery in 6 and in 3 of 15 episodes (60%), respectively. Priming of the donor with G-CSF was well tolerated, the most common side-effects being bone pain, malaise and paresthesia. All donors are alive and well after a median of 4.5 years (range 0.8-7.7) from donation. We conclude that GTX is potentially useful when the severity of the infection and the host's immunodeficiency make any other antimicrobial treatment ineffectual. Long-term safety data on the stimulation of donors with G-CSF have been reassuring to date. Further controlled studies are needed to assess the exact role of GTX in the outcome of neutropenic patients with severe infection and any criteria for patient selection and the timing of GTX administration.

Successful engraftment and stable full donor chimerism after myeloablation with thiotepa, fludarabine, and melphalan and CD34-selected peripheral allogeneic stem cell transplantation in hemophagocytic lymphohistiocytosis

Allogeneic hematopoietic stem cell transplantation (HSCT) represents the only curative option for primary hemophagocytic lymphohistiocytosis (HLH), a rare disease of infants and young children, characterized by recurrent fever, hepatosplenomegaly, and cytopenia. We report a case of successful engraftment and stable full-donor chimerism in a patient with HLH who underwent peripheral allogeneic CD34-selected HSCT. The donor was his 1-antigen-HLA-mismatched grandmother. After a conditioning regimen based on the combination of thiotepa, fludarabine, melphalan, and rabbit antilymphocyte serum, the patient received a megadose of 26.3 x 10(6)/kg of CD34(+) peripheral blood cells. Neutrophil (>0.5 x 10(9)/L) and platelet (>50 x 10(9)/L) engraftment was observed on days +16 and +12, respectively, and the patient was discharged home on day +24. No acute or chronic GVHD was observed. Infectious complications were the main causes of re-hospitalization in the first year after transplantation, but no significant morbidity was observed thereafter. Thirty-two months after HSCT, the patient is alive and well, still in complete clinical remission of his underlying disease with a durable engraftment, normal NK activity and full donor chimerism. This case suggests that a fludarabine-based conditioning regimen and CD34-selected peripheral allogeneic HSCT may be a feasible option in case of unavailability of a fully HLA-matched related or unrelated donor.

Development of a new bioartificial liver using a porcine autologous biomatrix as hepatocyte support

Long-term maintenance of hepatocyte viability and differentiated function expression is crucial for bioartificial liver support. The maintenance of hepatocyte function in a bioreactor is still a problem. A major advance was the recognition that hepatocytes in attachment cultures can maintain their differentiation longer. To restore hepatocyte polarity and prolong their function, we developed a new bioreactor with a cross-flow geometry configuration and an original hepatocyte extracellular autologous biomatrix (Porcine Bio-Matrix) support. To test this new bioreactor, we compared it with a standard bioartificial liver cartridge in a suitable surgical model of acute liver failure in pigs. In our model, we performed a total hepatectomy, followed by partial liver transplantation after an 18 hour anhepatic phase. The results showed that the bioreactor containing the biomatrix was able to bridge the animal to transplantation and to sustain the transplanted liver until all function recovered (80% of animals survived, p = 0.0027). No animal survived more than 24 hours after liver transplantation in the group treated with the traditional bioartificial liver, whereas hepatocyte viability on the Porcine Bio-Matrix was 65% after 12 hours of treatment. The results suggest that our biomatrix is a suitable cell support and guarantees long-term maintenance of metabolic activity of hepatocytes. Further studies are needed, but the results obtained with this new three-dimensional bioreactor are promising, and its potential is attractive.

The use of cytokine-stimulated healthy donors in allogeneic stem cell transplantation

Treatment of healthy donors with recombinant human granulocyte colony-stimulating factor (rhG-CSF) allows the mobilization and peripheralization into circulating blood of an adequate number of CD34+ cells that can then be collected by leukapheresis (PBSC). This procedure avoids the invasiveness of bone marrow harvest and the risks related to general anesthesia. The main adverse effects of rhG-CSF are: bone pain, 84%, headache, 54%, fatigue, 31%, and nausea, 13%, which are usually scored by the donors as moderate to severe, resolving within 2-3 days after discontinuation of the cytokine. Analgesics, mainly acetaminophen, are sufficient to control the pain. Less than 5% of the donors experience non-cardiac chest pain, a local reaction at the injection site, insomnia, dizziness or a low-grade fever. Discontinuation of the PBSC procedure because of adverse effects of rhG-CSF or leukapheresis is rarely necessary (0.5%) but this good tolerability can be hampered by the need, in 5-20% of cases, for an adequate venous access that requires insertion of a central or venous catheter. There are no absolute contraindications to the stimulation of healthy donors with rhG-CSF but the description of cases of non-traumatic splenic rupture, iritis, cardiac ischemia, and gouty arthritis suggests that further precautionary restrictions are advisable when deciding eligibility for PBSC collection. The main advantages for patients receiving an allogeneic PBSC transplant are the faster hematologic and immunologic recovery and the potential for a greater efficacy in advanced disease by lowering the transplant-related mortality. One of the major concerns regarding the use of rhG-CSF in unrelated healthy donors is the uncertainty about its possible role in triggering malignancy, in particular myelodysplastic syndrome and acute myeloid leukemia. There are no studies with an adequate sample size and follow-up that can answer this question but two recent retrospective studies reported that in the medium term rhG-CSF is not associated with an excess of lymphoproliferative disorders. Currently, caution on the long-term safety of the use of rhG-CSF in healthy donor is still warranted but the data so far accumulated on allogeneic PBSC transplants are encouraging both as far as concerns the good short-medium tolerability profile of G-CSF-stimulation of the donor and the potential major efficacy in leukemia patients.