Anti-ADAMTS13 Autoantibodies: From Pathophysiology to Prognostic Impact-A Review for Clinicians.

Thrombotic thrombocytopenic purpura (TTP) is a fatal disease in which platelet-rich microthrombi cause end-organ ischemia and damage. TTP is caused by markedly reduced ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13) activity. ADAMTS13 autoantibodies (autoAbs) are the major cause of immune TTP (iTTP), determining ADAMTS13 deficiency. The pathophysiology of such autoAbs as well as their prognostic role are continuous objects of scientific studies in iTTP fields. This review aims to provide clinicians with the basic information and updates on autoAbs' structure and function, how they are typically detected in the laboratory and their prognostic implications. This information could be useful in clinical practice and contribute to future research implementations on this specific topic.

Surgery and Prophylaxis with Susoctocog-Alfa in Acquired Hemophilia: Case Series and Literature Review.

BACKGROUND: Acquired hemophilia A (AHA) is a rare bleeding disease due to autoantibodies directed against clotting factor VIII (FVIII). Treatment of AHA consists of inhibitor eradication with immunosuppressive therapy (IST) and prompt control of bleeding obtained with bypassing agents or recombinant porcine FVIII (rpFVIII). The latter has recently been licensed for management of acute bleeding in AHA. Unlike treatment with bypassing agents, rpFVIII can be monitored to provide a successful hemostatic effect and avoid overtreatment. Correlation between rpFVIII inhibitor titers and efficacy of rpFVIII treatment remains a matter of debate. METHODS: We report three cases of AHA in which rpFVIII was successfully used with an unconventional schedule despite the presence of medium-high titers of the rpFVIII. The modified Nijmegen-Bethesda inhibitor assay (NBA) was used to dose porcine FVIII inhibitors. RESULT: The presence of rpFVIII inhibitors prior to the exposition to susoctocog-alfa, that may suggest a cross-reactivity with human FVIII inhibitors, did not affect hemostasis. CONCLUSION: In our experience, rpFVIII demonstrates safety and efficacy in the presence of rpFVIII inhibitors and using an unconventional schedule in both the perioperative and outpatient settings. Laboratory measurement of inhibitors against rpFVIII during treatment is described for the first time.

Impact of COVID-19 Infection, Vaccination, and Serological Response in Immune Thrombocytopenic Purpura Patients: A Single-Center Global Analysis.

Both SARS-CoV-2 infection and vaccination have raised concern in immune-mediated diseases, including immune thrombocytopenic purpura (ITP) considering risk of de novo ITP development and ITP recurrence. Here, we report on data from a single-center retrospective-prospective collection aiming to evaluate platelet (plt) dynamics in patients (pts) with chronic ITP after COVID-19 infection (before and after vaccination) and after the first, second and third vaccine doses. Furthermore, we analyzed the serological response after the first two doses of COVID-19 vaccination. A total of 64 pts currently followed for chronic ITP who experienced COVD-19 infection and/or vaccination with an available plt count before and after such events were included in the analysis. A low incidence of ITP exacerbation following vaccine sessions (6-16%) was observed in comparison with a high frequency of exacerbation and rescue treatment necessity after COVID-19 infection in unvaccinated pts (83%). Moreover, the lower ITP exacerbation rate observed in infected pts previously vaccinated (18%) suggests further protective effects in this population. Finally, a high seroconversion rate was observed, confirming data reported in previously published studies on immune cytopenia and rheumatological diseases, but more evidence is awaited to establish the clinical impact of serological response.

Management of patients with bleeding disorders and educational needs regarding hemophilia a in 23 italian emergency departments - Results from a survey conducted in Piedmont.

BACKGROUND: Haemophilia and von Willebrand disease are the bleeding disorders most frequently encountered in the emergency department (ED), that are often the first point of contact for patients. Evidence suggests that management in the ED is currently suboptimal, mainly because the physicians have few opportunities to deal with this kind of patients. OBJECTIVES: We carried out a survey to investigate the management of patients with haemophilia A in Emergency Departments (EDs), and to understand the training needs of the involved physicians. METHODS: Overall, in Piedmont Region there are 32 EDs, and considering that our survey was conducted on 21 physicians working in 23 Emergency Departments (EDs), this number is representative of the Region's reality. The interviews were conducted through face-to-face meetings, including general aspects regarding the clinical characteristics and the management of patients, and self-evaluation of knowledge and interest in receiving information about the disease. RESULTS: In 2019, 131 patients with haemophilia A were admitted (108 adults, 23 paediatric). The best-known and most widely available and used treatments were plasma derivatives, followed by first- and second-generation recombinant FVIII. More recent recombinant and bypassing agents were less known. Half of the interviewees considered their -knowledge of bleeding disorders in general and haemophilia in particular to be "basic", and only one third defined it as "good"; however, 86% expressed great interest in receiving information about the topic. CONCLUSIONS: The survey confirms the needs related to the clinical management of rare inherited clotting disorders in EDs. The physicians involved are keen to overcome this lack of knowledge, and proper initiatives should be implemented.

ADAMTS13 Autoantibodies and Burden of Care in Immune Thrombotic Thrombocytopenic purpura: New Evidence and Future Implications.

The introduction Caplacizumab in the management of Immune thrombotic thrombocytopenic purpura (iTTP) has raised different questions, considering its cost-efficacy and the optimal immunosuppressive treatment (IST) to associate. A retrospective multicenter collection of 42 first iTTP cases was conducted to identify variables associated with a higher burden of care and necessity of an implemented IST with early Rituximab (RTX) rescue. A significant correlation resulted between ADAMTS13 inhibitors (ADAMTS13inh) at diagnosis with total plasma exchange (PEXtot) and PEX needed to achieve clinical response (PEXtoCR, r = 0.46; r = 0.48), along with age (r = - 0.31; r = -0.35), platelet count (r = -0.30; r = -0.30), LDH (r = 0.44; r = 0.41) and total bilirubin (r = 0.54; r = 0.35). ADAMTS13inh also correlated with number of days of hospitalization (DoH, r = 0.44). A significant difference was observed in terms of median ADAMTS13inh titer at diagnosis in patient treated with RTX rescue and those responding to only steroid treatment. Thus, ADAMTS13inh titer resulted a marker of iTTP burden of care, associated with higher number of PEXtot, PEXtoCR, DoH and higher probability of needing RTX rescue to achieve clinical response and could be a useful tool for management of new iTTP cases and an interesting variable to optimize iTTP cases stratification in future Caplacizumab cost-efficacy analysis.

Simulation of the Impact on the Workload of the Enlargement of the Clinical Staff of a Specialistic Reference Center.

Quality of care and patient satisfaction are important aspects of high standard care. If clinical staff is subject to an elevated workload there is a possible decrease of both. This justifies the development of tools to quantify the workload and to find organizational changes that will normalize it. We have previously developed a simulation system to quantify the workload of the staff working in a regional reference center for the treatment of bleeding and hemorrhagic disorders. The goal of this new work is to simulate, through an agent-based model, the impact of adding a physician to the staff. Ten sets of initial parameters were defined to simulate ten typical weeks. Results show that the introduction of the new physician together with a second ambulatory room can reduce the workload of all the staff to the expected 8-hour. In this situation, in which the staff workload does not exceed the daily capacity, we may suppose that an increase in the quality of care and patient satisfaction will be possible.

Eltrombopag second-line therapy in adult patients with primary immune thrombocytopenia in an attempt to achieve sustained remission off-treatment: results of a phase II, multicentre, prospective study.

Up to 30% immune thrombocytopenia (ITP) patients achieve a sustained remission off-treatment (SROT) after discontinuation of thrombopoietin receptor agonists (TPO-RAs). Factors predictive of response are lacking. Patients aged ≥18 years with newly diagnosed or persistent ITP were treated with eltrombopag for 24 weeks. Primary end-point was SROT: the proportion of responders that were able to taper and discontinue eltrombopag maintaining the response during a period of observation (PO) of six months. Secondary end-points included the association between some immunological parameters (TPO serum levels, cytokines and lymphocyte subsets) and response. Fifty-one patients were evaluable. Primary end-point was achieved in 13/51 (25%) treated patients and 13/34 (38%) patients who started the tapering. Baseline TPO levels were not associated with response at week 24 nor with SROT. Higher baseline levels of IL-10, IL-4, TNF-α and osteopontin were negative factors predictive of response (P = 0·001, 0·008, 0·02 and 0·03 respectively). This study confirms that SROT is feasible for a proportion of ITP patients treated with eltrombopag. Some biological parameters were predictive of response.

Susoctocog-alfa (Obizur®) in the treatment of nine elderly patients with acquired haemophilia A: an Italian multicentre real world experience.

BACKGROUND: In 2016, a new recombinant B-domain deleted porcine FVIII (rpFVIII) was licensed in Italy for the treatment of acquired haemophilia A (AHA), but only a few cases of patients receiving this have been reported in the literature. Here we report the largest registry of the use of rpFVIII for the treatment of AHA. The objective of this retrospective study was to describe the efficacy and the safety of susoctocog-alfa for AHA. MATERIAL AND METHODS: We studied a population of nine patients, recruited in five Italian haemophilia centres presenting AHA, and treated with Obizur® as first- or second-line therapy. RESULTS: rpFVIII was used as a first-line therapy in one-third of the patients. The median delay between clinical onset and diagnosis was 16 days. Initial bolus of infused susoctocog-alfa was 100 IU/kg, lower than the recommended dose. The treatment was maintained for a median of four days. Only one patient with serious co-morbidities and recurrent infections was treated for 32 days. All patients reached a complete resolution of AHA, and no recurrences were reported. Two patients developed a low-titre inhibitor against rpFVIII, neither experienced any complications. DISCUSSION: In our real world experience, susoctocog-alfa was proven to be an effective and safe therapeutic option for patients with AHA, also at a lower than recommended dosage. In our report, the appearance of low-titre inhibitors against rpFVIII, was not found to be clinically significant.

Agent-Based Modeling and Simulation of Care Delivery for Patients with Thrombotic and Bleeding Disorders.

The quality of patients care delivery is thought to be strongly affected by the physicians' workload. In this study we present an Agent-Based model of the processes during a typical working day. We simulated the current scenario and a possible scenario concerning the introduction of a second ambulatory as a potential improvement in the center organization. Our results validated the reliability of the model and showed that the introduction of a second ambulatory averagely reduces the daily physician' workload.

Extended half-life rFIX in major surgery-How to improve clinical practice: An intraindividual comparison.

Practical, safe, and effective hemostatic approach to orthopedic surgery using Extended Half-Life factor IX in hemophilia B. By intraindividual comparison, we found a lower FIX consumption, number of infusions, and cost compared to plasma-derived FIX.

Identification and functional characterization of a novel splicing variant in the F8 coagulation gene causing severe hemophilia A.

BACKGROUND: We have identified a synonymous F8 variation in a severe hemophilia A (HA) patient who developed inhibitors following factor VIII (FVIII) prophylaxis. The unreported c.6273 G > A variant targets the consensus splicing site of exon 21. OBJECTIVES: To determine the impact of c.6273 G > A nucleotide substitution on F8 splicing and its translated protein. METHODS: Patient peripheral blood mononuclear cells were isolated and differentiated into monocyte-derived macrophages (MDMs). FVIII distribution in cell compartments was evaluated by immunofluorescence. The splicing of mutated exon 21 was assessed by exon trapping. Identified FVIII splicing variants were generated by site-directed mutagenesis, inserted into a lentiviral vector (LV) to transduce Chinese hamster ovary (CHO) cells, and inject into B6/129 HA-mice. FVIII activity was assessed by activated partial thromboplastin time, whereas anti-FVIII antibodies and FVIII antigen, by ELISA. RESULTS: HA-MDMs demonstrated a predominant retention of FVIII around the endoplasmic reticulum. Exon trapping revealed the production of two isoforms: one retaining part of intron 21 and the other skipping exon 21. These variants, predicted to truncate FVIII in the C1 domain, were detected in the patient. CHO cells transduced with the two FVIII transcripts confirmed protein retention and absence of the C2 domain. HA mice injected with LV carrying FVIII mutants, partially recovered FVIII activity without the appearance of anti-FVIII antibodies. CONCLUSIONS: Herein, we demonstrate the aberrant impact of a FVIII synonymous mutation on its transcription, activity, and pathological outcomes. Our data underline the importance of increasing the knowledge regarding the functional consequences of F8 mutations and their link to inhibitor development and an effective replacement therapy.

Eltrombopag for immune thrombocytopenia secondary to chronic lymphoproliferative disorders: a phase 2 multicenter study.

Immune thrombocytopenia (ITP) secondary to chronic lymphoproliferative disorders (LPDs) is poorly responsive to conventional treatments. We conducted a multicenter phase 2 prospective 24-week study in 18 patients with ITP secondary to LPDs to assess the safety and efficacy of eltrombopag. Responsive patients entered an extension study for up to 5 years. For inclusion, patients should not require cytotoxic treatment and should have a platelet count <30 × 109/L or have symptoms of bleeding. Eltrombopag was initiated at 50 mg/day, with a maximum of 150 mg/day. The primary end point was platelet response after 4 weeks. Median age was 70 years (range, 43-83 years), and 14 patients had chronic lymphocytic leukemia, 2 had classic Hodgkin lymphoma, and 2 had Waldenström macroglobulinemia. All patients had received previous ITP treatments. Response rate at week 4 was 78% (95% confidence interval [CI], 58%-97%), with 50% of patients having a complete response (CR) (95% CI, 43%-57%); respective results at week 24 were 59% (95% CI, 36%-82%) with 30% reaching a CR (95% CI, 8%-52%). Median exposure to eltrombopag was 16 months; median dose at week 4 was 50 mg/day (range, 25-100 mg/day), and at week 24, it was 50 mg/day (range, 25-150 mg/day). No grade >2 adverse events were reported. Eltrombopag is active and well tolerated in ITP secondary to LPDs. This trial was registered at www.clinicaltrials.gov as #NCT01610180.

Patient-Specific iPSC-Derived Endothelial Cells Provide Long-Term Phenotypic Correction of Hemophilia A.

We generated patient-specific disease-free induced pluripotent stem cells (iPSCs) from peripheral blood CD34+ cells and differentiated them into functional endothelial cells (ECs) secreting factor VIII (FVIII) for gene and cell therapy approaches to cure hemophilia A (HA), an X-linked bleeding disorder caused by F8 mutations. iPSCs were transduced with a lentiviral vector carrying FVIII transgene driven by an endothelial-specific promoter (VEC) and differentiated into bona fide ECs using an optimized protocol. FVIII-expressing ECs were intraportally transplanted in monocrotaline-conditioned non-obese diabetic (NOD) severe combined immune-deficient (scid)-IL2rγ null HA mice generating a chimeric liver with functional human ECs. Transplanted cells engrafted and proliferated in the liver along sinusoids, in the long term showed stable therapeutic FVIII activity (6%). These results demonstrate that the hemophilic phenotype can be rescued by transplantation of ECs derived from HA FVIII-corrected iPSCs, confirming the feasibility of cell-reprogramming strategy in patient-derived cells as an approach for HA gene and cell therapy.

Thrombopoietin receptor agonists in patients with persistent or chronic immune thrombocytopenia.

OBJECTIVES: To assess long-term treatment patterns and outcomes in patients with persistent or chronic immune thrombocytopenia (ITP), also considering the impact of the treatment with thrombopoietin receptor agonists (TPO-RAs) prior to splenectomy. METHODS: Medical records of all patients with persistent or chronic ITP seen at our institution between January 1985 and December 2016 were reviewed. Data on demographic and clinical characteristics were analyzed using descriptive statistics. Wilcoxon rank-sum test was used to compare medians between groups of patients. RESULTS: Among 80 patients with persistent or chronic ITP, 34 underwent splenectomy and 59 were treated with TPO-RAs. Twenty patients were both splenectomized and treated with TPO-RAs; among them, 9 received TPO-RAs before splenectomy. Median time to splenectomy from diagnosis of ITP was 25 months in the group of patients pretreated with TPO-RAs vs 14.5 months in the group of splenectomized patients. These differences were not statistically significant. CONCLUSIONS: Our study provides some initial data on the potential benefits of the treatment with TPO-RAs that may allow splenectomy to be safely deferred for prolonged periods. More research is needed to evaluate the impact of the treatment with TPO-RAs prior to splenectomy.

Khorana score and histotype predicts incidence of early venous thromboembolism in non-Hodgkin lymphomas. A pooled-data analysis of 12 clinical trials of Fondazione Italiana Linfomi (FIL).

Current data suggests that the risk of venous thromboembolism (VTE) in patients with non-Hodgkin lymphoma (NHL) is comparable to that observed in patients with solid tumours, although more robust confirmatory analyses are required. With that in mind, we investigated the occurrence of VTE in a pooled analysis of 12 "Fondazione Italiana Linfomi" (FIL) prospective clinical studies. Specifically, we wished to assess the cumulative incidence of VTE in NHL patients, evaluate the predictive value of the Khorana Score (KS), and identify other potential risk factors for VTEs. Data for VTE occurrence were retrieved from study databases and pharmacovigilance reports. Our analysis includes 1717 patients from 12 prospective phase II and III trials, including newly diagnosed NHL. We observed 53 VTEs (any grade) in 46 patients, with 20 severe VTEs in 17 patients. The cumulative incidences for "all-grade" or grade ≥3 VTEs were 2.9 % (95 % CI: 2.1-3.8) and 1.1 % (95 % CI: 0.6-1.6), respectively. KS categories were positively associated with the risk of VTE of any grade, and with severe events (i. e. grade ≥3; Gray's test p-values = 0.048 and 0.012, respectively). Among NHL patients, those with diffuse large B-cell lymphoma (DLBCL) showed a greater risk of (any grade) VTE (HR: 3.42, 95 % CI: 1.32-8.84, p-value = 0.011). Our study indicates that 1) VTE is a relevant complication for NHL patients, 2) KS is predictive of VTE events and 3) DLBCL histotype is an independent risk factor for VTE incidence, for which preventative interventions could be considered.

Cost-consequence analysis of long-term prophylaxis in the treatment of von Willebrand disease in the Italian context.

PURPOSE: Prophylaxis with von Willebrand factor (VWF)/factor VIII (FVIII) concentrates is a potential approach for patients with severe von Willebrand disease (VWD). As far as we are aware, to date there have been no pharmacoeconomic analyses in order to assess the economic impact of treatments for severe VWD. The analysis presented here estimates the cost-benefit ratio of VWF with a low FVIII content when compared with VWF/FVIII concentrates currently used in Italy for long-term prophylaxis in patients with severe VWD. METHODS: A cost-consequence analysis was undertaken to assess the economic impact of the treatment of severe VWD from the perspective both of the Italian National Health Service and society. The analysis was based on four case reports of long-term prophylaxis with VWD with VWF/FVIII concentrates and VWF with a low FVIII content. The costs per patient included direct and indirect costs for each treatment. RESULTS: Considering the four case reports, health care costs (without cost of treatment) and indirect costs per patient per year were lower with VWF with a low FVIII content than VWF/FVIII concentrates. The total health care costs (without cost of treatment) and indirect costs avoided with VWF with a low FVIII content per patient per year ranged from €2,295 to €17,530 and from €1,867 to €4,978, respectively. CONCLUSION: VWF with a low FVIII content seems to be a cost-effective treatment option for patients with severe VWD. Although the drug cost per se is higher, the use of VWF with a low FVIII content is associated with decreased consumption of hospital resources and fewer lost working days due to bleedings and consequently with an improvement of the quality of life of the patients.