Efficacy and safety of fitusiran prophylaxis in people with haemophilia A or haemophilia B with inhibitors (ATLAS-INH): a multicentre, open-label, randomised phase 3 trial.

BACKGROUND: Fitusiran, a subcutaneous investigational small interfering RNA therapeutic, targets antithrombin to rebalance haemostasis in people with haemophilia A or haemophilia B, irrespective of inhibitor status. We evaluated the efficacy and safety of fitusiran prophylaxis in people with haemophilia A or haemophilia B with inhibitors. METHODS: This multicentre, randomised, open-label phase 3 study was done at 26 sites (primarily secondary or tertiary centres) in 12 countries. Men, boys, and young adults aged 12 years or older with severe haemophilia A or haemophilia B with inhibitors previously treated with on-demand bypassing agents were randomly assigned (2:1) to receive once-a-month 80 mg subcutaneous fitusiran prophylaxis (fitusiran prophylaxis group) or to continue with bypassing agents on-demand (bypassing agents on-demand group) for 9 months. The primary endpoint was mean annualised bleeding rate during the efficacy period in the intention-to-treat population estimated by negative binomial model. Safety was assessed as a secondary endpoint in the safety population. This trial is complete and is registered with ClinicalTrials.gov, NCT03417102. FINDINGS: Between Feb 14, 2018, and June 23, 2021, 85 participants were screened for inclusion, of whom 57 (67%; 57 [100%] men; median age 27·0 years [IQR 19·5-33·5]) were randomly assigned: 19 (33%) participants to the bypassing agent on-demand group and 38 (67%) participants to the fitusiran prophylaxis. Negative binomial model-based mean annualised bleeding rate was significantly lower in the fitusiran prophylaxis group (1·7 [95% CI 1·0-2·7]) than in the bypassing agents on-demand group (18·1 [10·6-30·8]), corresponding to a 90·8% (95% CI 80·8-95·6) reduction in annualised bleeding rate in favour of fitusiran prophylaxis (p<0·0001). 25 (66%) participants had zero treated bleeds in the fitusiran prophylaxis group versus one (5%) in the bypassing agents on-demand group. The most frequent treatment-emergent adverse event in the fitusiran prophylaxis group was increased alanine aminotransferase in 13 (32%) of 41 participants in the safety population; there were no increased alanine aminotransferase treatment-emergent adverse events in the bypassing agents on-demand group. Suspected or confirmed thromboembolic events were reported in two (5%) participants in the fitusiran prophylaxis group. No deaths were reported. INTERPRETATION: Subcutaneous fitusiran prophylaxis resulted in statistically significant reductions in annualised bleeding rate in participants with haemophilia A or haemophilia B with inhibitors, with two-thirds of participants having zero bleeds. Fitusiran prophylaxis might show haemostatic efficacy in participants with haemophilia A or haemophilia B with inhibitors; therefore, the therapeutic might have the potential to improve the management of people with haemophilia. FUNDING: Sanofi.

FUBP3 regulates chronic myeloid leukaemia progression through PRC2 complex regulated PAK1-ERK signalling.

The development of resistance and heterogeneity in differential response towards tyrosine kinase inhibitors (TKI) in chronic myeloid leukaemia (CML) treatment has led to the exploration of factors independent of the Philadelphia chromosome. Among these are the association of deletions of genes on derivative (der) 9 chromosome with adverse outcomes in CML patients. However, the functional role of genes near the breakpoint on der (9) in CML prognosis and progression remains largely unexplored. Copy number variation and mRNA expression were evaluated for five genes located near the breakpoint on der (9). Our data showed a significant association between microdeletions of the FUBP3 gene and its reduced expression with poor prognostic markers and adverse response outcomes in CML patients. Further investigation using K562 cells showed that the decrease in FUBP3 protein was associated with an increase in proliferation and survival due to activation of the MAPK-ERK pathway. We have established a novel direct interaction of FUBP3 protein and PRC2 complex in the regulation of ERK signalling via PAK1. Our findings demonstrate the role of the FUBP3 gene located on der (9) in poor response and progression in CML with the identification of additional druggable targets such as PAK1 in improving response outcomes in CML patients.

Clinical phenotype, fibrinogen supplementation, and health-related quality of life in patients with afibrinogenemia.

Due to the low prevalence of afibrinogenemia, epidemiologic data on afibrinogenemia are limited, and no data are available on health-related quality of life (HRQoL). We conducted a cross-sectional international study to characterize the clinical features, the fibrinogen supplementation modalities, and their impact on HRQoL in patients with afibrinogenemia. A total of 204 patients (119 adults and 85 children) from 25 countries were included. The bleeding phenotype was severe: 68 (33.3%) patients having at least one bleed per month and 48 (23%) a history of cerebral bleeding. About 35% (n = 72) of patients were treated with fibrinogen concentrates or cryoprecipitates as prophylaxis, 18.1% (n = 37) received ≥1 injection per week, and 16.6% (n = 34) were on home treatment. A thrombotic event was reported in venous and/or arterial territories by 37 (18.1%) patients. Thrombosis occurred even in young patients, and recurrence was frequent (7.4%). The total HRQoL was lower in children than in adults. Discomfort linked to treatment and limitations to sports and leisure were the main concerns. Women and children were particularly affected in family relationships. In multivariate analyses, younger age, residence in Asia or Africa, and a previous thrombotic event were statistically correlated with a worse HRQoL. In summary, our study underlines the severe bleeding and thrombotic phenotype and their impact on HRQoL in afibrinogenemia. The optimal strategy for fibrinogen supplementation needs to be determined. This trial was registered at www.clinicaltrials.gov as #NCT03484065.

Rare Complication of a Rare Malignancy: Case Report of Cardiac Amyloidosis Secondary to Waldenstrom Macroglobulinemia.

Cardiac amyloidosis is a rare disorder caused by the myocardial deposition of abnormal fibrils. A 52-year-old man was referred to our center with clinical features of heart failure, after cardiac magnetic resonance imaging showed restrictive cardiomyopathy. Abdominal fat pad biopsy showed features of amyloidosis, and after hematological workup, he was diagnosed with Waldenstrom macroglobulinemia (WM). He was initiated on a rituximab-based chemotherapy regimen, and his cardiac function was assessed serially. Because of non-response, he was switched to a bortezomib-based regimen. Unfortunately, three days into this regimen, the patient died. WM is a rare plasma cell dyscrasia with a nonspecific presentation. It uncommonly presents with sequelae of amyloidosis-the IgM subtype of amyloid-light chain (AL) amyloidosis. Diagnostic delays are common, contributing to an already poor prognosis. Amyloidosis in WM requires urgent treatment - clonal chemotherapy, and supportive cardiac care in heart involvement. Bortezomib-based regimens are commonly recommended, with diuretics as the mainstay for cardiac treatment. However, in most advanced cases, the prognosis is poor; thus, a high degree of suspicion is necessary for early diagnosis. This case illustrates the possible presentation of cardiac amyloidosis as a rare malignancy.

Effect of point mutation on structure-function correlation of hemoglobin variants, HbE and HbD Punjab.

Hemoglobinopathies are examples of autosomal recessive disorders of human hemoglobin. Hemoglobin E (HbE) and Hemoglobin D Punjab (HbD Punjab) are two of the most common hemoglobin variants geographically spread across Asian continent. These two variants differ from normal human hemoglobin (HbA) at a single amino acid residue caused by the point mutation of ß globin gene. The presence of the mutated amino acid residue causes perturbation in the function of both variants. However, the structure-function correlation of these variants has not been established yet. In the present study, we analyzed the conformational changes associated with oxygenation of hemoglobin variants using hydrogen/deuterium exchange-based mass spectrometry of backbone amide hydrogens of α and ß globin chains in the tetrameric hemoglobin molecule. We also performed the functional assay of these variants using oxygen dissociation equilibrium curve. Compared to HbA, both variants showed reduced oxygen affinity, as reported earlier. The functional perturbations exhibited by these variants were correlated well with their structural alterations with respect to the reported changes in the residue level interactions upon oxygenation of normal hemoglobin, monitored through the hydrogen/deuterium exchange kinetics of several peptic peptides originated from the isotopically exchanged oxy and deoxy forms of HbE and HbD Punjab.

A Randomized Trial of Factor VIII and Neutralizing Antibodies in Hemophilia A.

BACKGROUND: The development of neutralizing anti-factor VIII alloantibodies (inhibitors) in patients with severe hemophilia A may depend on the concentrate used for replacement therapy. METHODS: We conducted a randomized trial to assess the incidence of factor VIII inhibitors among patients treated with plasma-derived factor VIII containing von Willebrand factor or recombinant factor VIII. Patients who met the eligibility criteria (male sex, age <6 years, severe hemophilia A, and no previous treatment with any factor VIII concentrate or only minimal treatment with blood components) were included from 42 sites. RESULTS: Of 303 patients screened, 264 underwent randomization and 251 were analyzed. Inhibitors developed in 76 patients, 50 of whom had high-titer inhibitors (≥5 Bethesda units). Inhibitors developed in 29 of the 125 patients treated with plasma-derived factor VIII (20 patients had high-titer inhibitors) and in 47 of the 126 patients treated with recombinant factor VIII (30 patients had high-titer inhibitors). The cumulative incidence of all inhibitors was 26.8% (95% confidence interval [CI], 18.4 to 35.2) with plasma-derived factor VIII and 44.5% (95% CI, 34.7 to 54.3) with recombinant factor VIII; the cumulative incidence of high-titer inhibitors was 18.6% (95% CI, 11.2 to 26.0) and 28.4% (95% CI, 19.6 to 37.2), respectively. In Cox regression models for the primary end point of all inhibitors, recombinant factor VIII was associated with an 87% higher incidence than plasma-derived factor VIII (hazard ratio, 1.87; 95% CI, 1.17 to 2.96). This association did not change in multivariable analysis. For high-titer inhibitors, the hazard ratio was 1.69 (95% CI, 0.96 to 2.98). When the analysis was restricted to recombinant factor VIII products other than second-generation full-length recombinant factor VIII, effect estimates remained similar for all inhibitors (hazard ratio, 1.98; 95% CI, 0.99 to 3.97) and high-titer inhibitors (hazard ratio, 2.59; 95% CI, 1.11 to 6.00). CONCLUSIONS: Patients treated with plasma-derived factor VIII containing von Willebrand factor had a lower incidence of inhibitors than those treated with recombinant factor VIII. (Funded by the Angelo Bianchi Bonomi Foundation and others; ClinicalTrials.gov number, NCT01064284; EudraCT number, 2009-011186-88.).

Ally to adversary: mesenchymal stem cells and their transformation in leukaemia.

Mesenchymal stem cells (MSC) are the key regulators of hematopoiesis. Owing to their dynamic nature; MSC differentiate into various lineages that further constitute the niche which are required for maintenance of the hematopoietic stem cells (HSC). A plethora of growth factors and cytokines secreted by MSC are essential for regulating the homeostasis within the niche in terms of cycling and quiescence of HSC. Additionally, there is a strong evidence suggesting the role of MSC in transformation of the niche to favour survival of leukemic cells. Regulation of HSC by MSC via BMP, Wnt, Notch and Sonic Hedgehog signalling has been well elaborated, however the modulation of MSC by HSC/LSC is yet unresolved. The cross talk between the HSC and MSC via paracrine or autocrine mechanisms is essential for the transformation. There are some reports implicating cell adhesion molecules, growth factors and cytokines; in modulation of MSC function and differentiation. The role of exosome mediated modulation has also been reported in the context of MSC transformation however, much needs to be done to understand this phenomenon in the present context. Similarly, the role of circulating nucleic acids, a well-studied molecular phenomenon in other tumours, requires attention in their potential role in crosstalk between MSC and HSC. This review underlines the current understanding of the physiological and pathophysiological roles of MSC and its transformation in diseased state, laying stress on developing further understanding of MSC regulation for development of the latter as therapeutic targets.

Molecular insights of inhibition in sickle hemoglobin polymerization upon glutathionylation: hydrogen/deuterium exchange mass spectrometry and molecular dynamics simulation-based approach.

In sickle cell anemia, polymerization of hemoglobin in its deoxy state leads to the formation of insoluble fibers that result in sickling of red blood cells. Stereo-specific binding of isopropyl group of ßVal6, the mutated amino-acid residue of a tetrameric sickle hemoglobin molecule (HbS), with hydrophobic groove of another HbS tetramer initiates the polymerization. Glutathionylation of ßCys93 in HbS was reported to inhibit the polymerization. However, the mechanism of inhibition in polymerization is unknown to date. In our study, the molecular insights of inhibition in polymerization were investigated by monitoring the conformational dynamics in solution phase using hydrogen/deuterium exchange-based mass spectrometry. The conformational rigidity imparted due to glutathionylation of HbS results in solvent shielding of ßVal6 and perturbation in the conformation of hydrophobic groove of HbS. Additionally, molecular dynamics simulation trajectory showed that the stereo-specific localization of glutathione moiety in the hydrophobic groove across the globin subunit interface of tetrameric HbS might contribute to inhibition in polymerization. These conformational insights in the inhibition of HbS polymerization upon glutathionylation might be translated in the molecularly targeted therapeutic approaches for sickle cell anemia.

Efficacy and safety of a new human fibrinogen concentrate in patients with congenital fibrinogen deficiency: an interim analysis of a Phase III trial.

BACKGROUND: Fibrinogen concentrate is the preferred choice for fibrinogen replacement in congenital fibrinogen deficiency. This study investigated hemostatic efficacy of a new plasma-derived, double virus-inactivated (using two dedicated virus inactivation/elimination steps) human fibrinogen concentrate for on-demand treatment of bleeding episodes (BEs) and surgical prophylaxis. STUDY DESIGN AND METHODS: In this planned interim analysis of a prospective, multinational Phase III study (NCT02267226), 13 patients with afibrinogenemia (≥12 years) received fibrinogen concentrate (FIBRYGA, Octapharma AG). Hemostatic efficacy was assessed by investigators and an independent data monitoring and endpoint adjudication committee (IDMEAC) using objective four-point criteria and by thromboelastometry maximum clot firmness (MCF). RESULTS: Fibrinogen concentrate was used on-demand to treat 23 BEs in 11 patients, with 21 (91.3%) requiring a single infusion only. Treatment success was 95.7% (90% confidence interval [CI], 0.81-1.00; assessment missing for one BE) by investigators and 100% (90% CI, 0.88-1.00) by IDMEAC. Mean MCF increased significantly from 0.0 to 6.5 mm (95% CI, 5.65-7.40; p < 0.0001) at 1 hour postinfusion of a median (range) dose of 58.8 (33.9-101.7) mg/kg per BE. Four patients received fibrinogen concentrate as surgical prophylaxis, with intraoperative and postoperative treatment success rated 100% (90% CI, 0.50-1.00) by investigators and IDMEAC (median [range] dose per surgery 93.5 [34.1-225.4] mg/kg). No additional hemostatic interventions were required. No deaths, thromboses, or seroconversions were reported. CONCLUSION: These data showed that the new fibrinogen concentrate was efficacious for on-demand treatment of acute bleeding and surgical prophylaxis in congenital afibrinogenemia patients.

Flap cover in a patient with severe haemophilia type A.

Haemophilia A is a rare haematological disorder due to deficiency of Factor VIII, causing an abnormal coagulation response to injury. In severe haemophilia A, Factor VIII level is < 1%, often manifesting with spontaneous bleeding into joints. Judicious use of recombinant Factor VIII therapy to maintain adequate levels in the intraoperative, immediate and late post-operative periods, together with adjuvant pro-coagulants, can ensure a safe outcome following surgery. We describe the successful management of one such patient suffering from Marjolin's ulcer of the right gluteal region, who needed wide local excision followed by flap cover. A protocol for management of such patients is also suggested. This is the first such case report from the Indian subcontinent, with only a few such published reports from the West.

Mass Spectrometry-Based Diagnosis of Hemoglobinopathies: A Potential Tool for the Screening of Genetic Disorder.

Hemoglobinopathies are caused by point mutation in globin gene that results in structural variant of hemoglobin. While 7 % of world populations are carrier of hemoglobinopathies, the prevalence of the disease varies between 3 to 17 % across different population groups in India. In a diagnostic laboratory, alkaline gel electrophoresis and cation exchange-based HPLC (CE-HPLC) are most widely used techniques for characterization of hemoglobin variants. In the above methods, the differential surface charge of hemoglobin molecule in variants is exploited for their characterization. Sometime, co-migration of variants in gel electrophoresis and co-elution or elution with unknown retention time in automated CE-HPLC might lead to ambiguity in the analysis of hemoglobinopathies. Under such circumstances, it is necessary to use other analytical methods that provide unambiguous results. Mass spectrometry-based proteomics approach and DNA sequence analysis are examples of such alternative methods. In the present study, liquid chromatography coupled to mass spectrometry has been used for three commonly observed variants in India, e.g., HbE, HbQ India and HbD Punjab that appeared with inappropriate results in the conventional analysis. A customized hemoglobin variant database has been used in the mass spectrometry-based analysis of those three variants. Mass spectrometry-based proteomics approach was used to analyze above variant sample accurately.

Mass spectrometry based characterization of Hb Beckman variant in a falsely elevated HbA(1c) sample.

Glycated hemoglobin (HbA1c) is a 'gold standard' biomarker for assessing the glycemic index of an individual. HbA1c is formed due to nonenzymatic glycosylation at N-terminal valine residue of the ß-globin chain. Cation exchange based high performance liquid chromatography (CE-HPLC) is mostly used to quantify HbA1c in blood sample. A few genetic variants of hemoglobin and post-translationally modified variants of hemoglobin interfere with CE-HPLC-based quantification, resulting in its false positive estimation. Using mass spectrometry, we analyzed a blood sample with abnormally high HbA1c (52.1%) in the CE-HPLC method. The observed HbA1c did not corroborate the blood glucose level of the patient. A mass spectrometry based bottom up proteomics approach, intact globin chain mass analysis, and chemical modification of the proteolytic peptides identified the presence of Hb Beckman, a genetic variant of hemoglobin, in the experimental sample. A similar surface area to charge ratio between HbA1c and Hb Beckman might have resulted in the coelution of the variant with HbA1c in CE-HPLC. Therefore, in the screening of diabetes mellitus through the estimation of HbA1c, it is important to look for genetic variants of hemoglobin in samples that show abnormally high glycemic index, and HbA1c must be estimated using an alternative method.

Interaction of iron deficiency anemia and hemoglobinopathies among college students and pregnant women: a multi center evaluation in India.

Although iron deficiency anemia is very common in India, systematic large studies on the prevalence and hematological consequences of iron deficiency among carriers of ß-thalassemia (ß-thal) and other hemoglobinopathies are lacking. A multi center project was undertaken to screen college/university students and pregnant women for iron deficiency anemia and various hemoglobinopathies. Fifty-six thousand, seven hundred and seventy-two subjects from six states, Maharashtra, Gujarat, Karnataka, West Bengal, Assam and Punjab, were studied. Iron deficiency anemia was evaluated by measuring zinc protoporphyrin (ZPP) and hemoglobin (Hb) levels, while ß-thal and other hemoglobinopathies were detected by measuring the red cell indices and by Hb analysis using high performance liquid chromatography (HPLC). College boys (2.2%), college girls (14.3%) and antenatal women (27.0%) without any hemoglobinopathies had iron deficiency anemia. Among the ß-thal carriers, the prevalence of iron deficiency anemia was 17.3% in college boys, 38.1% in college girls and 55.9% in pregnant women, while in the Hb E [ß26(B8)Glu→Lys; HBB: c.79G>A] carriers, it was 7.3% in college boys, 25.4% in college girls and 78.0% in antenatal women. In individuals with Hb E disease, the prevalence of iron deficiency anemia varied from 31.2-77.3% in the three groups. A significant reduction in Hb levels was seen when iron deficiency anemia was associated with hemoglobinopathies. However, the Hb A2 levels in ß-thal carriers were not greatly reduced in the presence of iron deficiency anemia.

Musculoskeletal disorders in sickle cell anaemia--unusual associations.

Sickle cell anaemia coexisting with gout is a rare clinical association, as is gout and eosinophilia. This report records the second case of chronic tophaceous deposits in Sickle cell anaemia. The patient also had eosinophilia in association with gout. Skeletal fluorosis was an incidental finding in this patient. Treatment with packed cell transfusions, hydroxyurea and colchicine lead to the resolution of anaemia and symptoms of acute gout.

Guidelines for screening, diagnosis and management of hemoglobinopathies.

The ß-thalassemias and sickle cell disorders are a major health burden in India. Diagnosis and management of these disorders both in adults and in newborns using appropriate approaches and uniform technology are important in different regions of a vast and diverse country as India. In view of a National Thalassemia Control Program to be launched soon, a need was felt for guidelines on whom to screen, cost-effective technologies that are to be used as well as for establishing prenatal diagnosis programs in regional centers. Newborn screening for sickle cell disorders is in its infancy in India and uniform approaches need to be followed. Also, included are guidelines for monitoring and managing patients who are now growing older and need comprehensive care as well as management of complications of the disease.

Reduced Volume and Faster Infusion Rate of Activated Prothrombin Complex Concentrate: A Phase 3b/4 Trial in Adults with Hemophilia A with Inhibitors.

Background Activated prothrombin complex concentrate (aPCC) is indicated for bleed treatment and prevention in patients with hemophilia with inhibitors. The safety and tolerability of intravenous aPCC at a reduced volume and faster infusion rates were evaluated. Methods This multicenter, open-label trial (NCT02764489) enrolled adults with hemophilia A with inhibitors. In part 1, patients were randomized to receive three infusions of aPCC (85 ± 15 U/kg) at 2 U/kg/min (the approved standard rate at the time of the study), in a regular or 50% reduced volume, and were then crossed over to receive three infusions in the alternative volume. In part 2, patients received three sequential infusions of aPCC in a 50% reduced volume at 4 U/kg/min and then at 10 U/kg/min. Primary outcome measures included the incidence of adverse events (AEs), allergic-type hypersensitivity reactions (AHRs), infusion-site reactions (ISRs), and thromboembolic events. Results Of the 45 patients enrolled, 33 received aPCC in part 1 and 30 in part 2. In part 1, 24.2 and 23.3% of patients with regular and reduced volumes experienced AEs, respectively; 11 AEs in eight patients were treatment related. AHRs and ISRs occurred in four (12.1%) and two (6.1%) patients, respectively. In part 2, 3.3 and 14.3% of patients with infusion rates of 4 and 10 U/kg/min experienced AEs, respectively; only one AE in one patient was treatment related; no AHRs or ISRs were reported. Most AEs were mild/moderate in severity. Overall, no thromboembolic events were reported. Conclusions aPCC was well tolerated at a reduced volume and faster infusion rates, with safety profiles comparable to the approved regimen.

Management of pregnancy and delivery in congenital fibrinogen disorders: communication from the ISTH SSC Subcommittee on Factor XIII and Fibrinogen.

Congenital fibrinogen disorders (CFDs) are a heterogeneous group of rare congenital quantitative and/or qualitative fibrinogen deficiencies. The spectrum of molecular anomalies is broad, leading to several subtypes of fibrinogen disorders (ie, afibrinogenemia, hypofibrinogenemia, dysfibrinogenemia, and hypodysfibrinogenemia). Pregnancy in women with CFDs is a high-risk clinical situation, with an increased tendency for miscarriages, bleeding, and thrombosis. Even though it is well established that management of such pregnancies requires a multidisciplinary approach involving specialists (hematologists and maternal/fetal medicine experts with expertise in the management of inherited bleeding disorders), specific guidelines are lacking. In this International Society on Thrombosis and Haemostasis (ISTH) Scientific and Standardization Committee communication, we aim to propose an expert consensus opinion with literature evidence where available on the strategy for management of pregnancy, delivery, and puerperium in CFDs.

Correction: Expert Opinions on the Management of Hemophilia A in India: The Role of Emicizumab.

[This corrects the article DOI: 10.7759/cureus.58941.].

Expert Opinions on the Management of Hemophilia A in India: The Role of Emicizumab.

Hemophilia A (HA) is a genetic disorder of hemostasis associated with a deficiency or reduced activity of clotting factor VIII (FVIII). This disorder remains unacceptably underdiagnosed in India. Early diagnosis and appropriate management of HA can substantially prevent morbidity and mortality. Currently, HA is managed with regular replacement therapy using standard or extended half-life FVIII concentrates or non-factor drug products. The challenges associated with FVIII concentrates include plateauing of drug effect, issues with its administration and adherence to treatment, breakthrough bleeds, and the development of inhibiting antibodies against administered clotting factors. Emicizumab is a bispecific antibody, launched in India in April 2019, for managing patients with HA. To investigate the role of emicizumab in Indian patients with HA, opinions were sought from 13 eminent hematologists and experts from India on the effectiveness of emicizumab in preventing all bleeds, spontaneous bleeds, perioperative bleeds, and intracranial hemorrhage; resolving target joints; and reducing the rate of hospitalizations and fatality associated with HA in children and adults, with or without inhibitors. The benefits of emicizumab over traditional FVIII concentrates include the subcutaneous route of delivery, less frequent dosing, and a lack of inhibitor development, in addition to providing sustained hemostasis without in-depth monitoring. It is a safe and effective management option for all HA patients, especially for patients with certain archetypes, such as those with inhibitors, those with high annualized bleed rates, those living far away from hemophilia care centers, pediatric patients and infants with intravenous access challenges, and those with a history of life-threatening bleeding events.

Automated analysis of hemoglobin variants using nanoLC-MS and customized databases.

Unambiguous analysis of hemoglobin variants is critical in the diagnosis of hemoglobinopathies. In diagnostic laboratories, alkaline gel electrophoresis and automated HPLC are used in identifying variants. In specific instances, comigration of hemoglobin variant bands in gel and coelution of different variants or elution of variants with unmatched library information in HPLC can result in ambiguities in interpretation. Hemoglobin variants mostly arise from point mutations leading to very high sequence homology between normal and variant hemoglobin. In addition, unavailability of a variant database compatible with proteomics data analysis software makes mass spectrometry based variant analysis very challenging. In the present study, we standardized a nanoLC-MS based method for variant analysis to achieve substantially high sequence coverage. We developed three hemoglobin variant databases, specific to three different proteolytic enzymes, compatible with proteomics search engine software. The above nanoLC-MS method and the compatibility of the customized databases were validated by analysis of a sickle hemoglobin variant. Six other hemoglobin variants were characterized wherein diagnosis reports based on conventional tools were ambiguous. The novelty of our method lies in its simplicity and accuracy of the analysis with minimal manual intervention. The presently described method may be used in the future for the routine hemoglobin variant diagnosis.