Dysfibrinogenemia and hypofibrinogenemia - Spectrum of pathogenic variants in Slovak patients.

INTRODUCTION: Congenital hypofibrinogenemia (CH) and congenital dysfibrinogenemia (CD) are rare coagulation disorders caused by quantitative or qualitative defects in the fibrinogen gene. The aim of this study was to characterize the genetic background and the clinical manifestations of congenital fibrinogen disorders in the patients from Slovakia registered at the National Haemophilia Centre. MATERIALS AND METHODS: Results of genetic analysis of the fibrinogen genes FGA, FGB and FGG using polymerase chain reaction followed by direct sequencing were evaluated in 36 patients. RESULTS: Molecular-genetic analysis revealed six novel variants - FGA c.923_968dup p.(Gly324Lysfs*44) and FGG c.1105C>T p.(His369Tyr) were identified in CD patients. In CH patients, in the FGG gene c.8G>A p.(Trp3*), c.823G>T p.(Glu275*) and c.323C>A p.(Ala108Asp) variants were detected. In the FGB gene c.1427C>T p.(Ser476Leu) was identified. CONCLUSION: This study is a positive contribution towards expanding knowledge about genetic variants in patients with congenital fibrinogen disorders.

Allogeneic hematopoietic stem cell transplantation from matched related donors for acute myeloid leukemia.

INTRODUCTION: In patients with acute myeloid leukemia (AML), allogeneic hematopoietic stem cell transplantation (HSCT) remains the priority treatment option as the most effective prevention of relapse. When an HLA-matched sibling is available, these transplants are preferred. OBJECTIVES: We stratificated patients according to risk, disease state (an active disease, the 1st or 2nd complete remission ‒ CR1, CR2, which was achieved after the 1st or 2nd induction) and type of graft (from brother or sister). Finally, the overall survival (OS) of patients in individual groups was evaluated. MATERIAL AND METHODS: The retrospective single-center study included 104 transplantations in 97 adult patients with AML who underwent HSCT from matched sibling donor in a period of 10 years between January 2011 and December 2020. RESULTS: 54 patients (55.7%) were alive as of the January 1, 2022. The median OS of the entire group, as well as the cohort with favorable (5y-OS 75.0%) and intermediate prognosis risk (5y‒OS 78.5%) was not reached. We found that patients, who required second induction therapy to achieve CR, had poorer OS after allogeneic HSCT, median 20.7 months (95% CI, 6.5-35.5) than those who achieved CR after first induction, median not reached (95% CI, 63.5‒63.5, p=0.0048). Statistically significant effect on OS shows transplantation in CR2 (HR 6.76, CI 95% 2.19‒20.80, p=0.0009), In addition, this parameter influenced OS more than achieving CR up to the 2nd induction course (HR 2.44, CI 95% 1.17‒5.11; p=0.0180) or entry to transplantation without CR (HR 2.81, CI 95% 1.09‒7.26; p=0.0326). CONCLUSION: The results presented in the work show the high efficiency of HSCT in each risk group. The number of induction therapies required to achieve CR is a good prognostic factor. The gender of a sibling has no impact on OS (Tab. 11, Fig. 7, Ref. 18). Text in PDF www.elis.sk Keywords: acute myeloid leukemia, allogeneic hematopoietic stem cell transplantation, overall survival, remission status, donor tender.

ASP210: a potent oligonucleotide-based inhibitor effective against TKI-resistant CML cells.

Clinical experience with tyrosine kinase inhibitors (TKIs) over the past two decades has shown that, despite the apparent therapeutic benefit, nearly 30% of patients with chronic myelogenous leukemia (CML) display primary resistance or intolerance to TKIs, and approximately 25% of those treated are forced to switch TKIs at least once during therapy due to acquired resistance. Safe and effective treatment modalities targeting leukemic clones that escape TKI therapy could hence be game changers in the professional management of these patients. Here, we aimed to investigate the efficacy of a novel therapeutic oligonucleotide of unconventional design, called ASP210, to reduce BCR-ABL1 mRNA levels in TKI-resistant CML cells, with the assumption of inducing their apoptosis. Imatinib- and dasatinib-resistant sublines of BCR-ABL1-positive MOLM-7 and CML-T1 cells were established and exposed to 0.25 and 2.5 µM ASP210 for 10 days. RT-qPCR showed a remarkable reduction of the target mRNA level by >99% after a single application. Cell viability was monitored daily by trypan blue staining. In response to the lack of driver oncoprotein BCR-ABL1, TKI-resistant CML cells underwent apoptosis regardless of the presence of the clinically relevant T315I mutation by day 5 after redosing with ASP210. The effect was selective for cancer cells, indicating a favorable safety profile for this therapeutic modality. Furthermore, the spontaneous uptake and high intracellular concentrations of ASP210 suggest its potential to be effective at relatively low doses. The present findings suggest that ASP210 is a promising therapeutic avenue for patients with CML who fail to respond to TKI therapy.NEW & NOTEWORTHY Effective treatment modalities targeting leukemic clones that escape tyrosine kinase inhibitor (TKI) therapy could be game changers in the professional management of patients displaying primary resistance, intolerance, or acquired resistance to TKIs. Although delivering authentic innovations today is more complex than ever, we developed a highly potent and safe oligonucleotide-based modality against BCR-ABL1 mRNA named ASP210 that effectively induces cell death in BCR-ABL1-positive TKI-resistant cells while sparing BCR-ABL1-negative healthy cells.

florio® HAEMO: A Longitudinal Survey of Patient Preference, Adherence and Wearable Functionality in Central Europe.

INTRODUCTION: florio® HAEMO is a hemophilia treatment monitoring application (app) offering activity tracking and wearable device connectivity. Its use might support everyday activities for people with hemophilia. The aim of this study was to evaluate user satisfaction, long-term usage and the impact on data entry when pairing a wearable with a hemophilia monitoring app. METHODS: This is a follow-up of a two-part user survey conducted in Central Europe. People with hemophilia and parents/caregivers of children with hemophilia using florio HAEMO and who completed part one were invited to complete a second online questionnaire at least 4 months later. RESULTS: Fifty participants (83.3%) who completed part one of the survey continued to use the florio HAEMO app and completed part two. Of 14 participants who chose to use the app with a wearable, more than half (57.1%) were aged between 13 and 25 years. Overall, the results demonstrated that florio HAEMO is very easy or rather easy to use, especially for individuals pairing the app with a wearable. Most people using a wearable indicated that florio HAEMO was very or rather important in bringing certainty to daily activities (85.7%). Notably, 14 of 36 (38.9%) non-wearable users indicated that they would prefer to pair the app with a wearable in the future. CONCLUSIONS: Adherence to the florio HAEMO app is maintained over an extended period of use. Pairing the app with a wearable might enable easier access to app features, increase data entry motivation and provide more certainty about daily activities for people with hemophilia.

Use of thrombopoietin receptor agonists in adults with immune thrombocytopenia: a systematic review and Central European expert consensus.

There are currently three thrombopoietin receptor agonists (TPO-RAs) approved in Europe for treating patients with immune thrombocytopenia (ITP): romiplostim (Nplate®), eltrombopag (Revolade®), and avatrombopag (Doptelet®). However, comparative clinical data between these TPO-RAs are limited. Therefore, the purpose of this study was to perform a literature review and seek expert opinion on the relevance and strength of the evidence concerning the use of TPO-RAs in adults with ITP. A systematic search was conducted in PubMed and Embase within the last 10 years and until June 20, 2022. A total of 478 unique articles were retrieved and reviewed for relevance. The expert consensus panel comprised ITP senior hematologists from eight countries across Central Europe. The modified Delphi method, consisting of two survey rounds, a teleconference and email correspondence, was used to reach consensus. Forty articles met the relevancy criteria and are included as supporting evidence, including five meta-analyses analyzing all three European-licensed TPO-RAs and comprising a total of 31 unique randomized controlled trials (RCTs). Consensus was reached on seven statements for the second-line use of TPO-RAs in the management of adult ITP patients. In addition, the expert panel discussed TPO-RA treatment in chronic ITP patients with mild/moderate COVID-19 and ITP patients in the first-line setting but failed to reach consensus. This work will facilitate informed decision-making for healthcare providers treating adult ITP patients with TPO-RAs. However, further studies are needed on the use of TPO-RAs in the first-line setting and specific patient populations.

Analysis of von Willebrand Disease in the "Heart of Europe".

Background von Willebrand disease (VWD) is a genetic bleeding disorder caused by defects of von Willebrand factor (VWF), quantitative (type 1 and 3) or qualitative (type 2). The laboratory phenotyping is heterogenic making diagnosis difficult. Objectives Complete laboratory analysis of VWD as an expansion of the previously reported cross-sectional family-based VWD study in the Czech Republic (BRNO-VWD) and Slovakia (BRA-VWD) under the name "Heart of Europe," in order to improve the understanding of laboratory phenotype/genotype correlation. Patients and Methods In total, 227 suspected VWD patients were identified from historical records. Complete laboratory analysis was established using all available assays, including VWF multimers and genetic analysis. Results A total of 191 patients (from 119 families) were confirmed as having VWD. The majority was characterized as a type 1 VWD, followed by type 2. Multimeric patterns concordant with laboratory phenotypes were found in approximately 83% of all cases. A phenotype/genotype correlation was present in 84% (77% type 1, 99% type 2, and 61% type 3) of all patients. Another 45 candidate mutations (23 novel variations), not found in the initial study, could be identified (missense 75% and truncating 24%). An exon 1-3 gene deletion was identified in 14 patients where no mutation was found by direct DNA sequencing, increasing the linkage up to 92%, overall. Conclusion This study provides a cross-sectional overview of the VWD population in a part of Central Europe. It is an addition to the previously published BRNO-VWD study, and provides important data to the International Society of Thrombosis and Haemostasis/European Association for Haemophilia and Allied Disorders VWD mutation database with identification of novel causal mutations.

Prevention and treatment of cancer associated venous thromboembolism - interdisciplinary consensus.

The increasing volume of the data and experience with direct oral anticoagulants (DOACS) in the primary and secondary prevention of venous thromboembolism in oncologic patients (CAVTE) has recently lead to changes in several international guidelines. We reflect these changes within the conditions in Slovak republic. In the primary prevention of CAVTE we recognise oncosurgical patients and nonsurgical patients: hospitalised and out patients. Low molecular weight heparins are still dominant in the primary prevention of CAVTE. Regarding the treatment and the secondary prevention of CAVTE, we recommend always to consider the possibility to use DOACs as they proved to be non inferior to LMWH. However, LMWH should be prefered over DOACs as well as over warfarin (VKA) in all patients who are in a clinically unstable condition with the high risk of bleeding and/or interaction with the systemic treatment. Primarily in the patients with intraluminal tumours of the upper part of the gastrointestinal tract and genitourinary tumours with the high risk of bleeding. As for the lack of data, LMWH are still preferd also in patients with primary tumours and metastatic disease of the central nervous system and in hemato oncology.

Expert opinion on current and future prophylaxis therapies aimed at improving protection for people with hemophilia A.

The next frontier in hemophilia A management has arrived. However, questions remain regarding the broader applicability of new and emerging hemophilia A therapies, such as the long-term safety and efficacy of non-factor therapies and optimal regimens for individual patients. With an ever-evolving clinical landscape, it is imperative for physicians to understand how available and future hemophilia A therapies could potentially be integrated into real-life clinical practice to improve patient outcomes. Against this background, nine hemophilia experts from Central European countries participated in a pre-advisory board meeting survey. The survey comprised 11 multiple-choice questions about current treatment practices and future factor and non-factor replacement therapies. The survey questions were developed to reflect current unmet needs in hemophilia management reflected in the literature. The experts also took part in a follow-up advisory board meeting to discuss the most important unmet needs for hemophilia management as well as the pre-meeting survey results. All experts highlighted the challenge of maintaining optimal trough levels with prophylaxis as their most pressing concern. Targeting trough levels of ≥30-50 IU/L or even higher to achieve less bleeding was highlighted as their preferred strategy. However, the experts had an equal opinion on how this could be achieved (i.e., more efficacious non-factor therapies or factor therapy offering broader personalization possibilities such as targeting trough levels to individual pharmacokinetic data). In summary, our study favors personalized prophylaxis to individual pharmacokinetic data rather than a "one-size-fits-all" approach to hemophilia A management to maintain optimal trough levels for individual patients.

Immune Tolerance Induction (ITI) with a pdFVIII/VWF Concentrate (octanate) in 100 Patients in the Observational ITI (ObsITI) Study.

Background Immune tolerance induction (ITI) with repeated factor VIII (FVIII) administration is the only strategy proven to eradicate inhibitors. The observational ITI study is evaluating ITI with a range of FVIII products. Methods This subgroup analysis reports prospective interim data for patients treated with a plasma-derived, von Willebrand factor-stabilized FVIII concentrate (pdFVIII/VWF, octanate). Complete success (CS) of ITI required achievement of three criteria: inhibitor titer < 0.6 BU/mL; FVIII recovery ≥ 66%; FVIII half-life ≥6 hours. Partial success (PS) required achievement of two criteria and partial response (PR) one. ITI success was defined as CS or PS. Data were analyzed for patients who achieved CS, had 36 months' observation, or failed ITI. Results One-hundred prospectively enrolled patients were included in the analysis; 91 had poor prognosis factors for ITI success. The mean (standard deviation) daily ITI dose was 116.4 (61.1) IU FVIII/kg in 14 low responders (< 5 BU/mL) and 173.7 (112.0) IU FVIII/kg in 86 high responders (≥ 5 BU/mL). Inhibitor titers < 0.6 BU/mL were achieved in 71% of patients in a median of 4.01 months, accompanied by a 93% reduction in bleeding rate. ITI success was achieved by 70% of patients and 56 of 72 (78%) primary (first-line) ITI patients. PR was achieved by 5 patients; ITI failed in 25 patients. PS and CS were achieved in a median of 5.55 and 11.25 months, respectively. Conclusions ITI with pdFVIII/VWF led to rapid eradication of FVIII inhibitors, normalization of FVIII pharmacokinetics in the majority of patients, and a significant reduction in bleeding rates.

First experience of a hemophilia monitoring platform: florio HAEMO.

Background: florio HAEMO is a new hemophilia treatment monitoring application consisting of a patient smartphone application (app) and a web-based dashboard for healthcare professionals, providing several novel features, including activity tracking, wearable connectivity, kids and caregiver mode, and real-time pharmacokinetic factor level estimation. Objectives: To assess intuitiveness, ease-of-use, and patient preference of florio HAEMO in Central Europe using a cross-sectional survey. Methods: This survey was conducted in six Central European countries between 9 December 2020 and 24 May 2021. The online questionnaire included 17 questions about overall satisfaction, ease-of-use, intuitiveness, and patient preference. Adults or children with hemophilia on regular prophylaxis and using the florio HAEMO app for a minimum of 1 week were invited to complete the online questionnaire by their treating physician. Results: Sixty-six participants took part in the survey. The median duration for all respondents using the florio HAEMO app was 3 to 4 weeks. Overall, 89.4% of users reported being very satisfied or rather satisfied after using florio HAEMO. Of the 23 respondents who had switched from another hemophilia app, 87.0% indicated that they strongly preferred or preferred using florio HAEMO. Most florio HAEMO users reported that the app was very easy or rather easy to use (97.0%) and intuitive (94.0%). florio HAEMO had a positive impact on daily living, with 78.8% of users reporting that the app was very important or rather important to them. Conclusions: This survey suggests that florio HAEMO is an easy-to-use and intuitive app to assist self-management of home prophylaxis.

Immune tolerance induction in the era of emicizumab - still the first choice for patients with haemophilia A and inhibitors?

INTRODUCTION: The development of inhibitory antibodies is a severe complication of clotting factor replacement therapy in patients with severe haemophilia A (HA). Current World Federation of Hemophilia (WFH) guidelines for haemophilia care indicate that eradication of inhibitors is best achieved through immune tolerance induction (ITI) therapy. AIM: The European Collaborative Haemophilia Network conducted a survey to determine whether ITI is still used in the routine management of patients with HA, and whether the availability of emicizumab prophylaxis has influenced treatment decisions. METHODS: The survey was conducted in late 2020/early 2021 in 18 centres representing 17 countries in the Europe/Middle East region treating a total of 4955 patients, and included sections specific to patient and centre demographics, treatment protocols (both ITI and prophylactic), inhibitor development and initiation of ITI, treatment success, and the incidence of adverse events. RESULTS: While our results indicate that ITI can still be considered a mainstay of treatment for patients with HA with inhibitors, less than daily dosing of ITI in combination with emicizumab prophylaxis is becoming commonplace across the spectrum of disease severity, with initiation being guided by bleeding patterns. The most frequently cited reasons for not initiating emicizumab prophylaxis were availability or reimbursement issues. CONCLUSION: ITI remains a mainstay for haemophilia treatment of patients with HA with inhibitors, but emicizumab has become a preferred first-line approach to protect against bleeds and represents an alternative to burdensome ITI in certain patient groups.

Treatment of Adults and Young Adults with Acute Lymphoblastic Leukemia: Real Life Data from Two Centers in Slovakia.

INTRODUCTION: The results of treatment of acute lymphoblastic leukemia (ALL) from the low population countries are missing in the literature. PATIENTS AND METHODS: We retrospectively examined biological characteristics and survival of 90 patients with ALL. RESULTS: At median follow-up 17 months, 52 men and 38 women were eligible for the analysis with median age 43 years (18-74). As for the risk stratification, 25.6% of patients were in standard risk, 46.7% in high risk and 27.8% in very high-risk group. Complete remission achieved 88.9% of patients. We observed 5.6% of induction deaths and 4.5% of resistant disease. 47.8% of the patients underwent allogeneic stem cell transplantation (alloSCT), 59% in the young adults (YA; < 40 years) and 40% in adult group (≥ 40 years). We noticed 32.6% relapses overall with median survival of relapsed patients 3.9 months. YA patients had longer survival than adults: 3-year overall survival (OS) 65.0% vs 30.2%; (HR = 0.36; 95% CI 0.2-0.64; P = .001) and event free survival (EFS) 51.5% vs 21.9%; (HR = 0.45; 95% CI 0.26-0.78; P = .005). There was significant difference in 3-year EFS between risk groups in YA patients 90.9%, 48.0%, 11.4%; (P = .001). OS after alloSCT individually for the YA was 62.6% and for adults 39.1%, hazard ratio (HR) = 0.49 (95% CI 0.20-1.21); (P = .095). We observed 14% early deaths, 25.6% late deaths and 3 relapses (7%) after allogeneic stem cell transplantation. CONCLUSIONS: Our data proved that even in a low population country similar result can be achieved as in larger ones while using well designed adapted protocols from leukemic study groups.

A Cross-National Survey of People Living with Hemophilia: Impact on Daily Living and Patient Education in Central Europe.

BACKGROUND: Information about the impact of hemophilia on daily living and information preferences for patients and their caregivers in Central Europe has been limited. METHODS: This cross-national survey was conducted between April 1 and October 15, 2020 and utilized a self-administered questionnaire to collect data (Typeform™) from people living with hemophilia in Bulgaria, Croatia, Czech Republic, Hungary, Slovakia and Slovenia. The questionnaire included 22 questions regarding difficulties in daily life and preferences for receiving hemophilia-related information. Respondents were stratified into two main groups, people with hemophilia (PwH) or their caregivers (CPwH). Results were analyzed using descriptive statistics. RESULTS: Of the 364 respondents, 232 were PwH (63.7%) and 132 were CPwH (36.3%). In total, 70.3% of hemophilia patients/caregivers responded that they are kept sufficiently informed about life with hemophilia, with 68.0%, 59.1% and 56.3% of respondents obtaining information from their physicians, patient associations and via digital media (internet and social media), respectively. However, 97.8% of respondents expressed an interest in additional information, particularly new hemophilia treatment options (62.1%), which in contrast to other topics was indicated most frequently by both patients and caregivers in all six countries. Most frequent difficulties in everyday life with hemophilia were identified as mobility problems (41.8%), unexpected bleeding (38.5%), pain (35.4%), and uncertainty with what they can or cannot do (25.0%). During the 2020 COVID-19 pandemic, 52.5% of respondents reported that they did not experience any major change in daily living with hemophilia. CONCLUSION: Based on our Central European survey, hemophilia mostly affects peoples' lives by causing mobility difficulties, unexpected bleeding, pain and uncertainty in daily activities. Although the majority of respondents reported being educated about hemophilia, most PwH and CPwH respondents sought additional information, highlighting the need for continuous personalized patient education to cope with present challenges.

Real-world effectiveness and safety of daratumumab, bortezomib and dexamethasone in relapsed/refractory multiple myeloma in Slovakia.

Real-world data on regimens for relapsed/refractory multiple myeloma (RRMM) are limited. Daratumumab in combination with bortezomib and dexamethasone is a promising new treatment. The aim of this analysis was to assess the outcomes of daratumumab-bortezomib-dexamethasone (DVd) combination for the treatment of patients with RRMM in a real-world setting. All consecutive RRMM patients who received at least two cycles of DVd treatment between December 2016 and July 2020 were identified. We analyzed the clinical characteristics and survival of 47 patients treated at 7 Slovak centers outside of the clinical trials. The median age was 65 years (range, 35 to 83). The median (range) number of lines of therapy per patient was 3 (2-6). All patients were previously exposed to PIs (proteasome inhibitors) and IMIDs (immunomodulatory drugs), the majority of patients (70.2%) had double refractory (IMIDs and PI) disease and 72.3% of patients were refractory to their last therapy. Most patients presented with high-risk characteristics, including 25.6% adverse cytogenetics and 25.5% extramedullary disease. The majority of patients responded with an overall response rate of 78%, we found complete response in 3, very good partial response in 22, partial response in 12, minor response or stable disease in 9, and progressive disease in 1 patient. After a median follow-up period of 8 months, the median progression-free survival was 10 months. There was a longer progression-free survival in those with 2 vs. >2 prior treatments, with equally good effectivity in standard-risk and high-risk cytogenetic groups. The adverse events were usually mild, none leading to permanent drug interruptions. Daratumumab-bortezomib-based combinations are efficacious and safe regimens in RRMM patients in the real-world setting. This is the first analysis in Slovakia addressing the DVd combination outside of the clinical trial setting.

Contemporary treatment methods of adult patients with BCR/ABL1 positive chronic myeloid leukemia.

Chronic myeloid leukemia (CML) is a clonal myeloproliferative neoplasia that is characterised by Philadelphia chromosome (Ph1 chromosome) and/or fusion gene BCR-ABL1 in bone marrow. Interpheron α and bone marrow transplantation used to be the main treatment modalities for patients with CML 20 years ago. Due to the introduction of imatinib mesylate since the year 2000 the outcome of CML patients has dramatically improved. The survival of both younger and elderly patients in the case of an optimal response has been prolonged and currently is close to survival of healthy population. Although, one third of patients does not respond well to first line imatinib and needs to change the treatment to second line tyrosine kinase inhibitors (TKI: bosutinib, dasatinib and nilotinib). Younger patients without cardiologic and metabolic disorders and those with poor risk profile score may have benefit from TKI of 2nd generation as a 1st line treatment option with the aim of reaching deeper molecular response and the chance of treatment free remission (TFR) in future. By older patients with severe comorbidities and in patients with good risk profile score imatinib as a 1st line treatment option can be used. For patients who are resistant simultaneously to 2nd generation TKI and for patients with mutation T315I ponatinib - TKI of 3rd generation can be used effectively. Intolerance and toxicity of TKI´s are the main barriers of effective CML treatment. TKI selection for each patient should be individual. Patient´s cooperation with medical team is crucial and inevitable in long time treatment process. The chance for TFR has become feasible for approximately 40-60 % CML patients in deep and durable molecular remission and represents a further important milestone in the management of CML patients.

Comparison of Two Different Techniques Of Warfarin Dosing Determination - A Chemometrics Study.

A high prevalence of genetic polymorphisms increases sensitivity to warfarin therapy. In this study, we investigated 47 patients with effective long-term therapy by warfarin well-controlled by monitoring of International Normalised Ratio (INR). All patients were tested for gene polymorphisms VKORC1, CYP2C9*C2, and CYP2C9*C3, which were used for a dose calculation employing a program www.WarfarinDosing.org. The main goal was to investigate whether the warfarin doses determined by INR are in accordance with the doses calculated according to the pharmacogenetic algorithm. For this purpose, several chemometric tools, namely principal component analysis, cluster analysis, correlation analysis, correspondence analysis, Passing-Bablock regression, Bland-Altman method, descriptive statistics, and ANOVA were used. We also analysed the relationship between the dose of warfarin determined by INR and several constitutional and genetic factors. Statistically significant association between clinically optimized warfarin dose and indication for the treatment, age, and warfarin sensitivity determined by VKORC1, CYP2C9 gene polymorphisms were confirmed. Finally, we confirmed a good concordance between the INR determined warfarin doses and pharmacogenetic approach.

The changing face of immune tolerance induction in haemophilia A with the advent of emicizumab.

INTRODUCTION: As a result of the new treatment paradigm that the haemophilia community will face with the availability of novel (non-factor) therapies, an updated consensus on ITI recommendations and inhibitor management strategies is needed. AIM: The Future of Immunotolerance Treatment (FIT) group was established to contemplate, determine and recommend the best management options for patients with haemophilia A and inhibitors. DISCUSSION AND CONCLUSIONS: Despite the considerable success of emicizumab in the management of inhibitor patients, the FIT group still sees the importance of eradicating inhibitors. However, the availability of emicizumab and other non-factor therapies in the future might impact greatly on how ITI is undertaken. Theoretically, concomitant use of emicizumab and FVIII might allow emicizumab to effectively prevent bleeding with lower dose ITI regimens. This might allow for the greater adoption of low-dose/low-frequency FVIII ITI regimens, which may result in a reduced need for central venous access devices while still maintaining a reasonable likelihood of ITI success. The FIT group proposes a new management algorithm for current ITI (without emicizumab) and a hypothetical new approach with the availability of emicizumab. As there are no published data regarding the concomitant use of emicizumab and FVIII for ITI, the FIT Expert group encourages the undertaking of properly conducted prospective studies to explore these approaches further.

Diagnostic Differentiation of von Willebrand Disease Types 1 and 2 by von Willebrand Factor Multimer Analysis and DDAVP Challenge Test.

The European Clinical Laboratory and Molecular (ECLM) classification of von Willebrand disease (vWD) is based on the splitting approach which uses sensitive and specific von Willebrand factor (vWF) assays with regard to the updated molecular data on structure and function of vWF gene and protein defects. A complete set of FVIII:C and vWF ristocetine cofactor, collagen binding, and antigen, vWF multimeric analysis in low- and medium-resolution gels, and responses to desmopressin (DDAVP) of FVIII:C and vWF parameters are mandatory. The ECLM classification distinguishes recessive types 1 and 3 vWD from recessive vWD 2C due to mutations in the D1 and D2 domains and vWD 2N due to mutations in the D'-FVIII-binding domain of vWF. The ECLM classification differentiates between mild vWD type 1 with variable penetrance of bleedings from symptomatic dominant type 1 vWD secretion defect and/or clearance defect with normal vWF multimers versus vWD 1M and 2M with normal or smeary vWF multimers in low- and medium-resolution gels. High-quality multimeric analysis of vWF in medium-resolution gels based on a DDAVP challenge test clearly delineates and distinguishes each of the dominant type 2 vWDs 1/2E, 2M, 2B, 2A, and 2D caused by vWF gene mutations in the D3 multimerization domain, loss or gain-of-function mutations in the glycoprotein Ib receptor A1 domain, gene mutations in the A2 proteolytic domain, and the C-terminal dimerization domain, respectively.