Pediatric immune thrombocytopenia: a focus on eltrombopag as second-line therapy

BACKGROUND

Immune thrombocytopenia (ITP) is the most common acquired bleeding disorder. In both children and adults, the primary goal of any therapeutic approach consists of cessation of bleeding and its prevention. Several options are currently available for first-line therapy in Europe, including corticosteroids and intravenous immunoglobulin (IVIg) infusion, which has a similar efficacy and safety profile in both the pediatric and adult populations. When second-line therapy is needed in the pediatric setting, current guidelines recommend eltrombopag as the drug of choice.

PROCEDURE

The aim of this article is to summarize the available evidence and present real-life experience on eltrombopag as second-line therapy in pediatric patients with ITP, with a focus on dosing and response to therapy as well as its tapering and discontinuation.

RESULTS

In our setting, eltrombopag is associated with good safety profile as well as promising efficacy; dose de-escalation was feasible in 94% of cases and often reached very low pro/kg dosage, with full discontinuation in 15% of cases. In daily practice, a standardized approach for discontinuation of eltrombopag in pediatric patients with ITP is still lacking. Herein, an easy-to-use scheme for tapering and discontinuation in candidate pediatric patients is proposed that proposes 25% dose reduction every four weeks.

CONCLUSIONS

In future management of pediatric ITP patients, it will be crucial to assess if thrombopoietin receptor agonists might be more effective in earlier phases of the disease and can modify the course of the disease.

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.

IDEAL study: A real-world assessment of pattern of use and clinical outcomes with recombinant coagulation factor IX albumin fusion protein (rIX-FP) in patients with haemophilia B in Italy

INTRODUCTION

Factor IX replacement therapy is used for treatment and prophylaxis of bleeding in haemophilia B. rIX-FP is an extended half-life albumin-fusion protein, which, in clinical studies, has demonstrated prolonged dosing intervals up to 21 days for routine prophylaxis, providing therapeutic benefit.

AIMS

To describe dosing frequency and consumption (primary endpoint), efficacy and safety of rIX-FP treatment during routine clinical practice in Italy.

METHODS

Patients with moderate/severe haemophilia B on prophylaxis with rIX-FP for ≥6 months, were enrolled in this observational study from October 2017 to February 2019 and followed-up for 2 years. Descriptive analysis included prospective and retrospective data (12 months prior to switching to rIX-FP).

RESULTS

Data were collected from 59 male patients (median age 30.1 years) enrolled by 23 Italian centres. Of them, 50 were on prophylaxis during the entire observation period and completed the study. The infusion frequency changed from 2-3 times/week in 86.0% of patients with previous treatment, to less than once a week in 84.0% of patients treated with rIX-FP at the 2nd-year follow-up. The annual number of infusions decreased by about 70%, whereas the mean FIX activity trough level increased from 3.8% to 14.4% (mean > 10% in all the infusion regimens). Median Annualised Bleeding Rate of .0 was achieved across all prophylaxis regimens. Subjects with zero bleedings increased from 66.0% to 78.0% with rIX-FP.

CONCLUSION

Treatment with rIX-FP reduced infusion frequency, while providing higher FIX trough levels with substantial benefit in terms of annualised bleeding rate and a good safety profile.

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.

Analytical Performance of Different Laboratory Methods for Measuring Susoctocog-Alfa

Recombinant porcine factor VIII (rpFVIII) is indicated for treating bleeding episodes in acquired haemophilia A, but there are few data regarding laboratory methods to adequately monitor treatment. This study involving three Italian laboratories aimed to evaluate the analytical performance of different assays for measuring rpFVIII. Five spiked rpFVIII samples (0.5–1.5 IU/mL) were analysed on three days, in triplicate, with eleven combinations of reagents (Werfen, Boston, MA, USA: SynthasIL and SynthaFax for one-stage assay, Chromogenix Coamatic FVIII for chromogenic assay), FVIII depleted plasmas (with or without von Willebrand factor—VWF) and calibrators (HemosIL human calibrator plasma, porcine calibrator diluted in FVIII deficient plasma with or without VWF). The assays were performed on ACL TOP analysers (Werfen, Boston, MA, USA). Intra- and inter-assay and inter-laboratory Coefficient of Variation (CV%) were calculated together with percentage of recovery (% recovery) on the expected value. The results showed that the reagent combinations reaching satisfactory analytical performance are: SynthasIL/human calibrator/deficient plasma+VWF (total recovery 99.4%, inter-laboratory CV 4.04%), SynthasIL/porcine calibrator/deficient plasma+VWF (total recovery 111%, inter-laboratory CV 2.75%) and Chromogenic/ porcine calibrator/deficient plasma+VWF (total recovery 96.6%, inter-laboratory CV 8.32%). This study highlights that the use of porcine standard (when available) and FVIII deficient plasma with VWF should be recommended.

Use of the von Willebrand factor concentrate with low factor VIII content to manage patients with inherited von Willebrand disease requiring surgical or secondary long-term prophylaxis: An expert opinion paper from an Italian panel

OBJECTIVES

The present review aims to summarize the state-of-the-art von Willebrand disease (VWD) treatment focusing on specific clinical settings (obstetrics, surgery, long-term prophylaxis and comorbidities) as well as on the use of a Von Willebrand factor (VWF) concentrate with low FVIII content.

METHODS

Literature research and case reports.

RESULTS AND CONCLUSIONS

Considering that patients affected by VWD have an intact ability to synthesize FVIII, in order to avoid excessive levels of FVIII, a highly purified plasma VWF concentrate with low FVIII content could be particularly useful in those patients and clinical circumstances at high thrombotic risk as well as for long-term prophylaxis. When deciding the optimal therapeutic strategy, physicians should take into account both the patient's history and the differences among available concentrates according to the clinical situations requiring treatment.

Intracranial Haemorrhage in Haemophilia Patients Is Still an Open Issue: The Final Results of the Italian EMO.REC Registry

Background: Intracranial hemorrhage (ICH) is a highly serious event in patients with haemophilia (PWH) which leads to disability and in some cases to death. ICH occurs among all ages but is particularly frequent in newborns. Aim: The primary aim was to assess the incidence and mortality due to ICH in an Italian population of PWH. Secondary aims were to evaluate the risk factors for ICH, the role of prophylaxis, and the clinical management of patients presenting ICH. Methods: A retrospective-prospective registry was established in the network of the Italian Association of Haemophilia Centers to collect all ICHs in PWH from 2009 to 2019 reporting clinical features, treatments, and outcomes. Results: Forty-six ICHs were collected from 13 Centers. The ICHs occurred in 15 children (10 < 2 years), and in 31 adults, 45.2% of them with mild hemophilia. Overall, 60.9% patients had severe haemophilia (15/15 children). Overall ICH incidence (×1000 person/year) was 0.360 (0.270−0.480 95% CI), higher in children <2 years, 1.995 (1.110−3.442 95% CI). Only 7/46 patients, all with severe haemophilia, had received a prophylactic regimen before the ICH, none with mild. Inhibitors were present in 10.9% of patients. In adult PWHs 17/31 suffered from hypertension; 85.7% of the mild subjects and 29.4% of the moderate/severe ones (p < 0.05). ICH was spontaneous in the 69.6% with lower rate in children (46.7%). Surgery was required in 21/46 patients for cerebral hematoma evacuation. Treatment with coagulation factor concentrates for at least three weeks was needed in 76.7% of cases. ICH was fatal in 30.4% of the cases. Of the survivors, 50.0% became permanently disabled. Only one-third of adult patients received long term prophylaxis after the acute treatment. Conclusion: The results from our Registry confirm the still high incidence of ICH in infants <2 years and in adults, particularly in mild PWHs presenting hypertension and its unfavorable outcomes. The majority of PWHs were treated on-demand before ICH occurred, suggesting the important role of prophylaxis in preventing such life-threatening bleeding.

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.

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.

Efficient and safe correction of hemophilia A by lentiviral vector-transduced BOECs in an implantable device

Hemophilia A (HA) is a rare bleeding disorder caused by deficiency/dysfunction of the FVIII protein. As current therapies based on frequent FVIII infusions are not a definitive cure, long-term expression of FVIII in endothelial cells through lentiviral vector (LV)-mediated gene transfer holds the promise of a one-time treatment. Thus, here we sought to determine whether LV-corrected blood outgrowth endothelial cells (BOECs) implanted through a prevascularized medical device (Cell Pouch) would rescue the bleeding phenotype of HA mice. To this end, BOECs from HA patients and healthy donors were isolated, expanded, and transduced with an LV carrying FVIII driven by an endothelial-specific promoter employing GMP-like procedures. FVIII-corrected HA BOECs were either directly transplanted into the peritoneal cavity or injected into a Cell Pouch implanted subcutaneously in NSG-HA mice. In both cases, FVIII secretion was sufficient to improve the mouse bleeding phenotype. Indeed, FVIII-corrected HA BOECs reached a relatively short-term clinically relevant engraftment being detected up to 16 weeks after transplantation, and their genomic integration profile did not show enrichment for oncogenes, confirming the process safety. Overall, this is the first preclinical study showing the safety and feasibility of transplantation of GMP-like produced LV-corrected BOECs within an implantable device for the long-term treatment of HA.

Italian experience with rVIII-single chain: a survey of patients with haemophilia A and their physicians

rVIII-SingleChain is indicated for treatment and prophylaxis of bleeding in patients with haemophilia A (HA). The safety and efficacy of rVIII-SingleChain have previously been shown in the AFFINITY clinical trial programme. This survey evaluated clinical experience following a switch to rVIII-SingleChain from the perspective of both physicians and patients. A web-based survey (July–September 2019) involving 14 Haemophilia Treatment Centres (HTCs) collected data about HA patients who were under treatment with rVIII-SingleChain for ≥ 12 months, as reported by their physicians. In addition, about half of these patients were separately interviewed. Out of 91 patients receiving rVIII-SingleChain in the 14 participating HTCs, 48 had been treated for ≥ 12 months; among those 48, 38% were ≤ 18 years, 37% 19–40 years and 25 % ≥ 41 years; 73% of them had severe HA and 85% were being treated with prophylactic therapy. Twenty-six patients accepted to be separately interviewed: mean age was 30 years; 62% had severe HA and 85% were receiving prophylaxis. Focusing on those patients who were already in prophylaxis with prior FVIII (all but one with recombinant factors), infusion frequency was significantly reduced from 3–2 per week following the switch to rVIII-SingleChain (mean, 2.74 vs. 2.44, respectively; p=0.013), as reported by physicians; the rate of patients needing 3 infusions per week dropped from 74% with previous products to 44% with rFVIII-SingleChain. The annual mean factor consumption was 4740 IU/Kg (median, 4500 IU/Kg; min, 2.215 IU/Kg; max, 7.200 IU/Kg) with prior product and 4320 IU/Kg (median, 4320 IU/Kg; min, 2.215 IU/Kg; max, 6.646 IU/Kg) with rVIII-SingleChain. Both physicians and patients reported a significant reduction in annual total bleeding rates with rVIII-SingleChain compared with prior product (mean 2.15–0.96 and 2.46–0.71 events/year, p = 0.031 and p = 0.018, respectively). Mean satisfaction ratings (from 1; dissatisfied, to 5; very satisfied) for rVIII-SingleChain were quite high for both physicians (4.14, 86% satisfied/very satisfied) and patients (4.18, 86% satisfied/very satisfied). This survey suggested that switching to rVIII-SingleChain allowed patients to reduce their injection frequency without increasing factor consumption or compromising clinical results. Both physicians and patients reported a positive experience with rVIII-SingleChain after 1 year of treatment.

Second-line administration of thrombopoietin receptor agonists in immune thrombocytopenia: Italian Delphi-based consensus recommendations

Introduction:

In patients with primary immune thrombocytopenia (ITP), a short course of steroids is routinely given as first-line therapy. However, the response is often transient and additional therapy is usually needed. Thrombopoietin receptor agonists (TPO-RAs) are frequently used as second-line therapy, although there is little clinical guidance on the timing of their administration and on tapering/discontinuation of the drug. To provide clinical recommendations, we used the Delphi technique to obtain consensus for statements regarding administration and on tapering/discontinuation of second-line TPO-RAs among a group of Italian clinicians with expertise in management of ITP.

Methods:

The Delphi process was used to obtain agreement on five statements regarding initiation and on tapering/discontinuation of second-line TPO-RAs. Agreement was considered when 75% of participants approved the statement. Eleven experts participated in the voting.

Results:

Full consensus was reached for three of the five statements. The experts held that an early switch from corticosteroids to a TPO-RA has the dual advantage of sparing patients from corticosteroid abuse and improve long-term clinical outcomes. All felt that dose reduction of TPO-RAs can be considered in patients with a stable response and platelet count >100 × 10⁹/L that is maintained for at least 6 months in the absence of concomitant treatments, although there was less agreement in patients with a platelet count >50 × 10⁹/L. Near consensus was reached regarding the statement that early treatment with a TPO-RA is associated with an increase in clinically significant partial or complete response. The experts also agreed that optimization of tapering and discontinuation of TPO-RA therapy in selected patients can improve the quality of life.

Conclusion:

The present consensus can help to provide guidance on use of TPO-RAs in daily practice in patients with ITP.

Plain language summary

Second-line administration of thrombopoietin receptor agonists in immune thrombocytopenia

Non-Compartment and compartmental pharmacokinetics, efficacy, and safety of Kedrion FIX concentrate

BACKGROUND

An open-label phase II, multicenter clinical trial was conducted at 11  Haemophilia Centres in  Italy, Romania, and Turkey, to evaluate the pharmacokinetics (PK), efficacy, and safety of high purity, plasma-derived, double virus inactivated and double nano-filtered factor IX (pd-FIX) concentrate (Kedrion FIX), EudraCT Number: 2005-006186-14.

MATERIAL AND METHODS

16 previously treated patients (PTPs) with severe or moderately severe haemophilia B were enrolled in the study. At enrolment, 14 underwent the first PK assessment (PK I), and the second PK (PK II) assessment was performed after six months of treatment (5 on-demand and nine prophylaxis) at the end of the study. PK parameters were evaluated by Non-Compartmental Analysis (NCA), One-Compartment model (OCM), and Two-Compartment Model (TCM). Efficacy of Kedrion FIX in all 16 patients was evaluated by the number of bleeding events, and clinical response following the infusions. Periodic FIX inhibitor assays and thrombogenicity tests were scheduled throughout the study to assess the safety of the drug.

RESULTS

As compared to the published data on PK of pdFIX, Kedrion FIX displayed a longer half-life (22.37-55.73 hrs), reduced clearance, and regular volume of distribution at PK I by both NCA and OCM. The comparison of outcomes of PK II with those of PK I by OCM,  also showed significant changes, particularly in patients on prophylaxis, who showed some improved parameters of PK. Due to two outlier values at the end of the trial, the NCA parameters of PK I were not compared to those of PK II. Breakthrough bleeds were successfully treated with 1 or 2 infusions. No significant adverse events were observed during the study.

DISCUSSION

During the six-month clinical study period, the use of Kedrion FIX resulted in a safe and effective pd-FIX concentrate with excellent PK characteristics.

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.

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.

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.

Characterization of Physicians Workload in a Reference Center for the Treatment of Thrombotic and Bleeding Disorders

Heavy workloads in healthcare have been often associated to adverse clinical outcomes. To reduce workloads, an optimal scheduling of clinical staff resources is not enough, but particular attention must be payed to work organization and task characteristics. Moreover, interruptions during the clinical practice contribute to increase perceived workloads. In this study we analyzed and characterized the physicians' workload in an Italian center for the treatment of thrombotic and bleeding disorders. First, all clinical and administrative processes performed in the center were analyzed by means of two process modelling tools. Then, the quantification of the physicians' workload and the characterization of interruptions during practice were conducted. From our results it emerged that the task that mainly impacts on the workload is ambulatory care (42% of total workload) while interruptions produce a delay of almost 15 minutes per day and mainly occur during visits. Including all activities, the total daily workload per physician was 8 hours on average. In this time breaks were not taken into account. Concluding, from our analysis it is evident that the physicians' workload in the analyzed center is heavy and interruptions represent a source of delay in the workflow, that impact the physicians' workload.

Immune tolerance induction with moroctocog-alpha (Refacto/Refacto AF) in a population of Italian haemophilia A patients with high-titre inhibitors: Data from REF.IT Registry

BACKGROUND

The appearance of inhibitors is the most serious complication in haemophilia A (HA) patients. The primary objective is their eradication. Up to date, immune tolerance induction (ITI) was the only therapeutic option to achieve this.

AIM

To assess the efficacy of moroctocog-alpha as an ITI regimen in a population of HA patients with high-titre inhibitors.

METHODS

The REF.IT Registry is a retrospective-prospective study that collected data on all patients with HA and high-titre inhibitors treated with moroctocog-alpha as an ITI regimen at twelve Italian Haemophilia Centres.

RESULTS

We enrolled 27 patients, 85.2% were children. All patients were high responders, 88.9% had severe HA. We found 69.3% of them had one or more risk factors for poor ITI prognosis, 14.8% were ITI rescue. Overall 59.3% achieved a complete/partial success (complete in 51.9%). ITI failed in 11 patients, 63.6% of them with poor-prognosis risk factors. Inhibitors appeared after a mean of 27 exposure days. Mean historical peak was 78.8 BU/mL. The primary ITIs started on average 20.2 months after the diagnosis. A partial or complete success after a mean of 15 months of treatment was achieved in 56.6% of the children while the same result was obtained by 75.0% adults after 22 months from ITI onset. Patients who were treated with high-dose moroctocog-alpha (200 UI/kg/day) were 63.0%.

CONCLUSION

Our Registry showed that the use of moroctocog-alpha in the setting of ITI was effective and safe also in a population of patients with high-titre inhibitors, presenting one or more risk factors for poor ITI prognosis.

Use of Modified Functional Assays for Activated Protein C Resistance in Patients with Basally Prolonged aPTT

Inherited resistance to activated protein C (APCr) is currently recognized as the most prevalent cause underlying venous thrombophilia, with an estimated prevalence around 20% in thrombotic patients and around 1.8-7% in the general population. A correct laboratory diagnosis of APCr is therefore essential. Two different diagnostic approaches are at present at our disposal: the semi-quantitative plasma test based on the measurement of two aPTTs (in the presence and absence of activated protein C), and the detection of the factor V Arg506 GIn mutation by DNA analysis.

In this study we firstly evaluated sensitivity, specificity and diagnostic efficiency of an aPTT-based plasma clotting test (Chromogenix, Sweden) versus DNA analysis; then, since the APC resistance test is invalidated by a basally prolonged aPTT (i.e. during warfarin and heparin therapy or in patients with clotting factor deficiencies or in the presence of a lupus anticoagulant), patient plasmas were conveniently diluted in factor V deficient plasma in order to correct clotting factor abnormalities. Nevertheless, patients with a LA and an aPTT ratio range 1.8-3.17 were still all misclassified. We obtained correct diagnoses in LA positive patients by preincubating plasmas with a mixture of phospholipids; therefore we decided to perform a double modified clotting test adding a mixture of platelet derived phospholipids to samples previously diluted in factor V deficient plasma. The performance characteristics of this novel method with a different aPTT reagent (Behring, Germany) were also evaluated. With this double modified test all patients were correctly classified as negative or positive for factor V mutation in agreement with DNA analysis, irrespectfully of the basal aPTT value and the aPTT reagent employed. We propose this modified version of the APCr clotting test as an easily reproducible, reliable, very sensitive and specific screening test which possibly reduces the need for DNA analysis.

Can pegylated interferon improve the outcome of polycythemia vera patients?

Pegylated interferon (peg-IFN) was proven by phase II trials to be effective in polycythemia vera (PV); however, it is not clear whether it could improve patient outcome compared to hydroxyurea (HU). Here, we present an observational study on 65 PV patients aged 65 years or younger, who received either peg-IFN (30) or HU (35) according to the physician choice. Median follow-up was 75 months. The two cohorts were comparable for patient and disease characteristics. Eighty-seven percent of the patients treated with peg-INF responded, with a CR rate of 70% as compared to 100 and 49% with HU, respectively. Discontinuation rate was similar in the two groups (20% in peg-IFN vs 17% in HU). JAK2 allele burden was monitored in peg-INF arm only, and a reduction was observed in 88% of the patients. No thrombotic events were observed during peg-IFN treatment compared to three on HU. Disease progression to myelofibrosis or acute myeloid leukemia occurred to a patient only in peg-INF, compared to three in HU. Overall, three second malignancies were observed during the study, two in patients who received HU only, and one in a patient largely treated HU who received also peg-IFN for 3 months. Overall survival was significantly better for peg-IFN patients compared to HU, p = 0.027. Our study, albeit limited by small patient and event number and lack of randomization, confirms the efficacy of peg-INF in PV and shows a significant survival advantage for peg-INF-treated patients. Waiting for confirming data from the ongoing phase III trials, our study can support peg-INF as a first-line treatment option for PV, at least for younger patients.

Health-related quality of life and burden of fatigue in patients with primary immune thrombocytopenia by phase of disease

The main objective of this study was to compare health-related quality of life (HRQOL) of primary immune thrombocytopenia (pITP) patients with that of general population, overall, and by patient group (i.e., newly diagnosed, persistent, and chronic patients). Fatigue was also investigated as a secondary objective. Overall, 424 adult patients were enrolled in a multicenter observational study and the control group consisted of a representative sample from the general population. Propensity score matching plus further multivariate linear regression adjustment was used to compare HRQOL outcomes between pITP patients and general population. Mean age of patients was 54 years. Of those with HRQOL assessment, 99 patients (23.6%) were newly diagnosed, 53 (12.6%) were persistent, and 268 (63.8%) were chronic pITP patients. Comparison by patient group versus their respective peers in the general population revealed greater impairments in persistent pITP patients. Persistent pITP patients reported clinically meaningful impairments in physical functioning (-15; 95% CI -24.1 to -5.8; P = 0.002), social functioning (-15.3; 95% CI -25.5 to -5.1; P = 0.004), role physical (-28.4; 95% CI -43.1 to -13.7; P < 0.001), role emotional (-23.9; 95% CI -40.1 to -7.7; P = 0.004), and mental health scales (-11.3; 95% CI -21.2 to -1.4; P = 0.026) of the SF-36 questionnaire. Higher fatigue severity was associated with lower physical and mental HRQOL outcomes. Our findings suggest that the burden of the disease and treatment might depend on the disease phase and that persistent pITP patients are the most vulnerable subgroup. Am. J. Hematol. 91:995-1001, 2016. © 2016 Wiley Periodicals, Inc.

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.

Cells carrying nonlymphoma-associated bcl-2/IgH rearrangements (NLABR) are phenotypically related to follicular lymphoma and can establish as long-term persisting clonal populations

OBJECTIVE

Nonlymphoma-associated bcl-2/IgH rearrangements (NLABRs) are frequently amplified by PCR in blood of lymphoma-free subjects (LFS), but the temporal kinetics and phenotypic nature of NLABR-positive cells are unknown. To address these issues we prospectively monitored a panel of NLABR-positive LFS.

METHODS

LFS have been studied by nested PCR, real-time PCR, and DNA sequencing. Cell selection studies were also performed to define the nature of NLABR-bearing clones.

RESULTS

Of 125 donors, 16 (12.8%) were found to be bcl-2/IgH positive and were monitored at least every 6 months for a median time of 22 months (range 6-50). In half of the subjects the same NLABR detected initially was again reamplified at follow-up thrice or more. In 5, the same NLABR was constantly amplified in every follow-up sample. With a median follow-up of 22 months (range 9-50), no stable disappearance of a recurrent clone has been so far recorded. Real-time PCR indicated that persistent NLABR-positive clones are stable over time in the same subject. Cell separation studies indicate that NLABRs belong to CD19+, CD5-, CD23-, CD10+/- cells.

CONCLUSIONS

Our results indicate that NLABR-positive clones are persistent populations phenotypically related to follicular lymphoma (FL). This suggests the existence of a FL-related clonal expansion of undetermined significance, which might be either a premalignant or a nonmalignant counterpart of FL.

Use of modified functional assays for activated protein C resistance in patients with basally prolonged aPTT

Inherited resistance to activated protein C (APCr) is currently recognized as the most prevalent cause underlying venous thrombophilia, with an estimated prevalence around 20% in thrombotic patients and around 1.8-7% in the general population. A correct laboratory diagnosis of APCr is therefore essential. Two different diagnostic approaches are at present at our disposal: the semi-quantitative plasma test based on the measurement of two aPTTs (in the presence and absence of activated protein C), and the detection of the factor V Arg506 Gln mutation by DNA analysis. In this study we firstly evaluated sensitivity, specificity and diagnostic efficiency of an aPTT-based plasma clotting test (Chromogenix, Sweden) versus DNA analysis; then, since the APC resistance test is invalidated by a basally prolonged aPTT (i.e. during warfarin and heparin therapy or in patients with clotting factor deficiencies or in the presence of a lupus anticoagulant), patient plasmas were conveniently diluted in factor V deficient plasma in order to correct clotting factor abnormalities. Nevertheless, patients with a LA and an aPTT ratio range 1.8-3.17 were still all misclassified. We obtained correct diagnoses in LA positive patients by preincubating plasmas with a mixture of phospholipids; therefore we decided to perform a double modified clotting test adding a mixture of platelet derived phospholipids to samples previously diluted in factor V deficient plasma. The performance characteristics of this novel method with a different aPTT reagent (Behring, Germany) were also evaluated. With this double modified test all patients were correctly classified as negative or positive for factor V mutation in agreement with DNA analysis, irrespectfully of the basal aPTT value and the aPTT reagent employed. We propose this modified version of the APCr clotting test as an easily reproducible, reliable, very sensitive and specific screening test which possibly reduces the need for DNA analysis.

Natural and acquired inhibitors of hemostasis in selected symptomatic outpatients with venous thromboembolic disease

BACKGROUND AND OBJECTIVE

Deficiencies of natural inhibitors and the presence of lupus anticoagulant are important risk factors leading to venous thromboembolic events. Before resistance to activated protein C (APC-R) was identified, the overall prevalence of inherited abnormalities of hemostasis in non-selected outpatients with venous thromboembolic disease was under 10%. This cast doubts on the of cost effectiveness and clinical significance of assaying hemostasis inhibitors in all such patients. The goal of this study is to evaluate the prevalence of inherited and acquired abnormalities of hemostasis in younger symptomatic outpatients with objectively diagnosed venous thromboembolic disease (VTD).

METHODS

From October 1994 to October 1996, we diagnosed, treated and followed 191 consecutive outpatients with an objective diagnosis of venous thromboembolic disease, and assayed natural and acquired hemostasis inhibitors in 81 of them aged less than 50; in addition, 129 relatives of patients with inherited deficiencies were evaluated.

RESULTS

Twenty-six of the patients under age 50 showed inherited deficiencies of natural inhibitors (3 antithrombin, 5 protein C, 3 protein 5 and 14 APC-R, 1 dysfibrinogenemia) and 8 patients had lupus anticoagulant (LA): abnormalities of hemostasis were found in 41.9% (95% confidence interval 31.1-53.5). In older selected patients, 60% (95% confidence interval 40.6-77.3) of the subjects showed abnormalities. Seventy-two of the relatives displayed natural inhibitor deficiencies; 88.5% of the families studied had at least one relative with the same defect as the propositus.

INTERPRETATION AND CONCLUSIONS

A simple selection based on age, clinical and family history shows the existence of a high prevalence and the important clinical significance of abnormalities of hemostasis in symptomatic outpatients with venous thromboembolic disease.

Lupus anticoagulant and thrombosis: role of von Willebrand factor multimeric forms

OBJECTIVE

Patients with lupus anticoagulant (LA) have an increased incidence of venous and arterial thrombosis whose pathogenesis is still unclear. High molecular weight von Willebrand Factor (vWF) multimers seem to play a causal role in shear stress-induced platelet aggregation and thrombus formation. We studied whether in patients with LA, alterations in the vWF multimers might coexist.

METHODS

The multimeric composition of plasma vWF was analysed by SDS-electrophoresis and immunoblotting in 43 subjects positive for LA. About 2/3 of the patients had had either ischemic stroke, recurrent abortions, deep vein thrombosis (DVT) or a combination of these; the remaining subjects had never had any thrombotic events.

RESULTS

An abnormal vWf multimeric pattern was found in 16 patients (37.2%); no correlation was found with the diagnosis, but the presence of abnormal vWF significantly correlated with the site of the thrombosis: indeed, it was never detected in subjects with DVT, but was found in 71.4% of patients with multiple abortions, in 50% of those with stroke and even in 25% of non-thrombotic patients.

CONCLUSION

The hypothesis is put forward that abnormal VWF may represent an additional risk factor to LA for arterial thrombosis.

Quantitative analysis of von Willebrand factor propeptide release in vivo: effect of experimental endotoxemia and administration of 1-deamino-8-D-arginine vasopressin in humans

The results of studies with cultured endothelial cells have shown that most von Willebrand factor (vWF) synthesized is directly secreted (constitutive pathway) and consists of both mature vWF, its precursor molecule pro-vWF, and the cleaved vWF prosequence. Only fully processed, functionally mature vWF is stored within the cell, together with the propeptide, and leaves the cell only on stimulation (regulated secretion). Both in resting and stimulated cultured endothelial cells, the stoichiometry of the released propeptide to the released mature vWF is essentially equimolar. In the present study, we have measured the molar ratio of propeptide to mature vWF in vivo, both under resting conditions and conditions that reflect activation of the endothelium. To this end, we devised a method that allows the measurement of the propeptide (vW antigen II) on a quantitative, is, molar basis, using purified recombinant propeptide as a standard. Our results show that the molar concentration of the propeptide in normal plasma is about one tenth of the concentration of mature vWF (expressed as half-dimer concentration). This ratio is approximately 1:1 in the medium of cultured endothelial cells. On administration in healthy subjects of either 1-deamino-8-D-arginine vasopressin or endotoxin, both agents being known to elicit an intravascular increase of vWF, the molar ratio of propeptide to mature vWF increased fourfold to fivefold. The propeptide concentration returned to baseline values after about 6 to 7 hours of injection of each stimulus, whereas the increase of mature vWF was much more sustained. Because the respective half-lives of mature vWF and its propeptide clearly differ, measurement of the concentration of these proteins could provide a means to assess the extent of activation of the endothelium under physiological and pathophysiological conditions.

Factor V Arg506-->Gln mutation in patients with antiphospholipid antibodies

Antiphospholipid antibodies (APA) have thought to be implicated in the pathogenesis of both arterial and venous thrombosis. Because of heterogeneity of APA, direct evidence of their involvement in a thrombotic event is not yet available. Development of thrombosis in the antiphospholipid antibody syndrome (APS) may occur because of the presence of additional risk factors. Here we have analysed 60 patients with APA for the presence of the Arg506-->Gln mutation in factor V. Among them 26 suffered from deep venous thrombosis, 13 from arterial thrombosis and 21 had no history of arterial or venous thrombosis. In the first group four patients were found to be heterozygous and one homozygous for the factor V Arg506-->Gln mutation. None of the patients with the factor V mutation was found in the second and third group. The incidence of factor V mutation was significantly elevated in the group of patients with venous thrombosis. These data suggest that in patients with antiphospholipid antibodies the factor V Arg506-->Gln mutation may play a major role in the occurrence of venous thrombosis.

Arterial and venous thrombosis in two Italian families with the factor V Arg506-->Gln mutation

APC resistance, due to a point mutation in factor V at amino acid position Arg506, has been identified as a major cause of inherited thrombophilia. Here we report the presence of the factor V Arg506-->Gln mutation in 2 Italian families. In 1 family 3 subjects heterozygous and 2 subjects homozygous for the factor V Arg506-->Gln mutation were identified. The only subject who developed a thrombotic event was a 20-yr-old girl who was found to be homozygous for the factor V Arg506-->Gln mutation. In the second family 10 subjects were identified to be heterozygous for the factor V Arg506-->Gln mutation; among them 2 developed a thrombotic event. In the same family 2 individuals were found to be homozygous for the mutation: the first had a myocardial infarction at age 25 yr and the second suffered from multiple episodes of deep venous thrombosis and had a stroke at age 24 yr. These data show that the risk of developing deep venous thrombosis for the carriers of the factor V Arg506-->Gln mutation is high in the families investigated. Furthermore our data imply that the factor V Arg506-->Gln mutation in its homozygous form may relate to myocardial infarction and stroke.

[Anomalies of coagulation and fibrinolytic activity in patients with chronic pulmonary thromboembolism]

INTRODUCTION

Haemostatic and fibrinolytic parameters were evaluated in patients with chronic pulmonary hypertension following pulmonary embolism (CPE). The diagnosis of CPE was based on lobar or segmental defects on perfusion lung scans and by pulmonary angiograms which showed complete or partial obstruction of main or segmentary lobar arteries.

METHODS

Antithrombin III (AT III), protein C, protein S, and lupus anticoagulant (LA) were assayed in 8 patients with CPE; in 6 out of 8 patients plasma fibrinolytic activity was assessed both under basal conditions and after venous stasis. The control group consisted of 4 normal subjects. Protein C and protein S antigens were assayed by an electrophoretic method. Protein C and protein S biological activities were assayed by a manual clotting system. AT III was assayed by chromogenic method. Fibrinolytic total activity was studied on fibrin plates, tPA and PAI-1 activities by chromogenic method; tPA and PAI-1 antigens by ELISA technique.

RESULTS

One patient out of 8 showed a protein C deficiency and 3 patients out of 8 were positive for a LA. All patients had a statistically significant reduction of plasma fibrinolytic activity (p < 0.001) and of tPA activity (p < 0.0005) after venous stasis as compared to the control group.

CONCLUSIONS

Our data show that significant haemostatic abnormalities may underlie this disease. In particular, a) an impairment of fibrinolytic plasma activity and low levels of plasminogen activator may be found, and b) the undiagnosed presence of a LA may be the cause of these thrombotic events. The meaning of these results needs further assessment.

Lupus anticoagulant: interference with in vivo prostaglandin production and with platelet sensitivity to prostacyclin

The hypothesis has been made that inhibition of prostacyclin (PG12) production may play a role in the pathogenesis of thrombosis in patients with the lupus anticoagulant (LA), but so far no evidence of reduced PG12 levels in vivo has been produced. We have tested the plasma levels of PG12 and thromboxane A2 (TXA2) and the platelet sensitivity to PG12 in 14 patients with and without LA and in 14 healthy controls. No significant difference in the prostanoid basal levels was detected among the groups; however, in some patients PG12 increments seemed to parallel the clinical course of the disease. Platelet sensitivity to exogenous PG12 was significantly enhanced in the LA + patients and correlated with PG12 values. We suggest that in these subjects additional factors, other than reduced PG12, may predispose to thrombosis.