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| 2. |
- Manderstedt, Eric, et al.
(author)
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Detection of F8 int22h inversions using digital droplet PCR and mile-post assays
- 2020
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In: Journal of Thrombosis and Haemostasis. - : Wiley-Blackwell. - 1538-7933 .- 1538-7836. ; 8:5, s. 1039-1049
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Journal article (peer-reviewed)abstract
- BACKGROUND: Inversions involving intron 22 (Inv22) of F8 are detected in approximately 45% of all severe hemophilia A patients. Diagnosis is complicated by the large size of the ~9.5 kb int22h repeated sequence which generates the inversions. Methods such as long-range PCR and inverse-shifting PCR are currently used diagnostically, but suffer from low PCR efficiencies and are difficult to standardize.OBJECTIVES: To design and validate a sensitive and robust assay for the detection of F8 int22h inversions.METHODS: Digital droplet PCR using mile-post assays was used to investigate archival DNA samples.RESULTS: The detection of linkage as a function of physical distance between loci was investigated using an anchor locus and mile-post loci located at 1, 6, 12 and 15 kb distances from the anchor locus. The proportion of linked molecules decreased with increasing distance between loci and showed 30-40% linked molecules for loci 12-15 kb apart. Mile-post assays specific for wild type and Inv22 type 1 and 2 chromosomes were then designed and optimized. All three assays showed high specificities and sensitivities, with coefficients of variation < 5% for all assays. Analysis of 106 patients and 20 carrier mothers showed complete concordance with previously known mutation status. The analysis demonstrated the robustness of the assays versus input DNA concentration (6 ng and higher) and level of fragmentation.CONCLUSIONS: Digital droplet PCR and mile-post assays can be used to detect F8 int22h inversions. The assay systems are technically simple to perform, highly efficient and robust.
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| 3. |
- Manderstedt, Eric, et al.
(author)
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Detection of mosaics in hemophilia A by deep Ion Torrent sequencing and droplet digital PCR
- 2020
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In: Research and practice in thrombosis and haemostasis. - : Wiley. - 2475-0379. ; 4:7, s. 1121-1130
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Journal article (peer-reviewed)abstract
- Background: The occurrence of mosaicism in hemophilia A (HA) has been investigated in several studies using different detection methods. Objectives: To characterize and compare the ability of AmpliSeq/Ion Torrent sequencing and droplet digital polymerase chain reaction (ddPCR) for mosaic detection in HA. Methods: Ion Torrent sequencing and ddPCR were used to analyze 20 healthy males and 16 mothers of sporadic HA patients. Results: An error-rate map over all coding positions and all positions reported as mutated in the F8-specific mutation database was produced. The sequencing produced a mean read depth of >1500X where >97% of positions were covered by >100 reads. Higher error frequencies were observed in positions with A or T as reference allele and in positions surrounded on both sides with C or G. Seventeen of 9319 positions had a mean substitution error frequency >1%. The ability to identify low-level mosaicism was determined primarily by read depth and error rate of each specific position. Limit of detection (LOD) was <1% for 97% of positions with substitutions and 90% of indel positions. The positions with LOD >1% require repeated testing and mononucleotide repeats with more than four repeat units need an alternative analysis strategy. Mosaicism was detected in 1 of 16 mothers and confirmed using ddPCR. Conclusions: Deep sequencing using an AmpliSeq/Ion Torrent strategy allows for simultaneous identification of disease-causing mutations in patients and mosaicism in mothers. ddPCR has high sensitivity but is hampered by the need for mutationspecific design.
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| 5. |
- Dolan, Gerard, et al.
(author)
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Recombinant FVIIa in elective non-orthopaedic surgery of adults with haemophilia and inhibitors : A systematic literature review
- 2021
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In: Haemophilia. - : Wiley. - 1351-8216 .- 1365-2516. ; 27:3, s. 314-330
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Research review (peer-reviewed)abstract
- Aim: To assess available evidence on the use of rFVIIa in non-orthopaedic surgery including dental surgery in adult patients with congenital haemophilia with inhibitors (PWHI). Methods: A systematic literature search was performed according to a prespecified search string; prespecified criteria were used to select applicable studies including PWHI ≥18 years of age who underwent any non-orthopaedic surgery using rFVIIa. Results: Thirty-three publications met the eligibility criteria, of which 26 publications – including 46 procedures in 44 patients – were selected for the qualitative analysis. Most publications were case reports or case series (21/26). Primary authors assessed rFVIIa as effective in maintaining haemostasis during and after most major surgeries (22/32). rFVIIa dose was mainly on label, with higher doses used in 4 cases, and a lower dose in 1 case. Duration of treatment was mostly 5–10 days (range: 3 days to 1 month post-operatively). Adverse events related to rFVIIa were rare. Conclusions: Assessing non-orthopaedic surgery in this patient population is hampered by a paucity of published data; nevertheless, the current evidence indicates that rFVIIa is effective in achieving haemostasis in haemophilia patients with inhibitors undergoing elective non-orthopaedic or dental surgery. rFVIIa was generally well tolerated in these patients, with thrombotic events occurring rarely. These data, generated to help clinicians manage congenital haemophilia with inhibitors, highlight the need for more systematic reporting of rFVIIa and all other therapeutic agents in non-orthopaedic surgery and dental surgery in patients with congenital haemophilia and inhibitors.
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| 6. |
- Lehtinen, A. E., et al.
(author)
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Surgical outcomes in patients with haemophilia A or B receiving extended half-life recombinant factor VIII and IX Fc fusion proteins: Real-world experience in the Nordic countries
- 2022
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In: Haemophilia. - : Wiley. - 1351-8216 .- 1365-2516. ; 28:5, s. 713-719
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Journal article (peer-reviewed)abstract
- Introduction Perioperative dosing recommendations vary across Nordic haemophilia treatment centres (HTCs) for extended half-life (EHL) factor concentrates in haemophilia A/B (HA/HB) patients. Aim To summarise Nordic real-world surgical experiences with EHL recombinant factor VIII/IX Fc (rFVIIIFc/rFIXFc) fusion proteins using retrospective data from clinical records at four HTCs in Finland, Sweden and Norway. Methods Factor dosing and surgical outcomes were recorded from HA/HB patients who underwent surgery and were treated with rFVIIIFc/rFIXFc. Perioperative factor dosing regimens were clinician-determined based on local practises. Results Twenty five surgeries were performed on 20 patients, all covered by bolus injections except one minor HA surgery; eight minor surgeries were in paediatric patients. Median preoperative rFVIIIFc dose for major HA surgeries (n = 8) was 48 IU/kg (range: 35-57), with total consumption up to Day 14 of 427 IU/kg (196-568). For the two major HB surgeries (in one patient), preoperative rFIXFc doses were 50 IU/kg and 20 IU/kg; total consumption up to Day 14 was 130 IU/kg and 40 IU/kg. Median preoperative rFVIIIFc/rFIXFc bolus doses for minor HA (n = 10) and HB (n = 4) surgeries were 50 IU/kg (24-79) and 47 IU/kg (40-71), with total consumption up to Day 5 of 138 IU/kg (49-404) and 100 IU/kg (43-125), respectively. Intraoperative and postoperative haemostatic responses were rated as at least good/excellent for 24/25 surgeries, with bleeding episodes reported in only three surgeries. Conclusion Nordic real-world experiences suggest that EHL products can be used safely and effectively for peri-operative haemostasis. Further research is required to develop local dosing guidelines for optimised treatment schedules.
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| 7. |
- Lövdahl, Susanna, et al.
(author)
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A longitudinal study of family structure in Swedish persons with haemophilia
- 2014
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In: Haemophilia. - : Wiley. - 1351-8216 .- 1365-2516. ; 20:4, s. 493-499
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Journal article (peer-reviewed)abstract
- Haemophilia is an X-linked inherited rare bleeding disorder affecting mainly men. The treatment consists of replacement therapy that has been associated with severe side effects, such as blood transmitted viral infections, but has markedly improved over the last decades. The aim of this study was to study family structure over time among Swedish persons with haemophilia (PWH), focusing on children, siblings and marital status. PWH A or B were identified from the haemophilia centres and the national Patient Registry. Each PWH was compared to five age- and gender-matched controls. The national Multi-Generation Registry was used to identify children and siblings. A total of 1365 children with a father suffering from haemophilia A or B and 1938 siblings of the PWH were identified. Having one or more children was significantly less common (P=0.003) for PWH than for controls. Significantly lower rates of having a child were also found for the subgroups of persons suffering from severe haemophilia and those infected with HIV (P<0.001). A higher proportion of PWH, with or without HIV and/or viral hepatitis had siblings compared to the controls (P<0.001). However, the mean number of siblings was significantly lower for persons with severe haemophilia (P=0.001). The number of marriages and divorces did not differ between PWH and controls. Our data indicate a negative impact of HIV and viral hepatitis on family structure for PWH despite the relatively good access to treatment in Sweden over the last few decades. This was particularly true for those with a severe form of haemophilia.
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| 8. |
- Lövdahl, Susanna, et al.
(author)
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Hypertension and cardiovascular diseases in Swedish persons with haemophilia - A longitudinal registry study
- 2019
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In: Thrombosis Research. - : Elsevier BV. - 0049-3848 .- 1879-2472. ; 181, s. 106-111
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Journal article (peer-reviewed)abstract
- Introduction: Data on the prevalence of hypertension and cardiovascular diseases (CVD) among persons with haemophilia (PWH) vary. Sweden has a long tradition of maintaining population-based data registries, and there is extensive follow-up of haemophilia patients due to the use of prophylaxis over decades. We evaluated the prevalence of these diseases among Swedish PWH compared to matched controls using a longitudinal study design. Methods: Data were obtained from the National Patient Registry and linked to records of persons with haemophilia enrolled in the haemophilia centres. For each subject, five gender and age matched controls were identified. Results: We identified 193 (19.7%) diagnoses of hypertension in PWH born in 1978 or earlier over >= 30 years compared with 550 (11.2%) among controls. The median ages and interquartile ranges were 60.0 (42.8, 69.9) and 57.2 (42.6, 70.6) years. The hazard rate (HR) for hypertension, PWH vs. controls, was 2.1, 95% CI: [1.8; 2.5], p < 0.001. The findings were similar in subgroup analyses of patients with non-severe and severe haemophilia with or without HIV and/or viral hepatitis. Angina pectoris was diagnosed in 69 (4.8%) of patients censored at age 75 compared with 311 (4.3%) in controls, and myocardial ischemia in 84 (5.9%) compared with 442 (6.2%). As a cause of death, the HR for myocardial ischemia, comparing PWH and controls, was 0.58, 95% CI: [0.42, 0.80], p = 0.001. Conclusion: Our data support an increased prevalence of hypertension among persons with haemophilia. The prevalence of CVD seems to be similar to that of controls, but with lower mortality.
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| 9. |
- Shapiro, Amy D., et al.
(author)
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Long-term efficacy and safety of subcutaneous concizumab prophylaxis in hemophilia A and hemophilia A/B with inhibitors
- 2022
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In: Blood Advances. - : American Society of Hematology. - 2473-9529 .- 2473-9537. ; 6:11, s. 3422-3432
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Journal article (peer-reviewed)abstract
- Despite current therapies, there remains an unmet need for treatment for patients with hemophilia. The main parts of two phase 2 trials established clinical proof-of-concept for once-daily, subcutaneous concizumab prophylaxis in patients with hemophilia A/B with inhibitors (HAwI/HBwI; explorer4) and severe hemophilia A without inhibitors (HA; explorer5). Here, we present results from extension parts of these trials, included to evaluate longer term safety and efficacy. Both trials included main ($24 weeks) and extension (52-102 weeks) parts, with patients receiving concizumab 0.15 mg/kg with potential dose escalation to concizumab 0.20 or 0.25 mg/kg if they experienced $3 treated spontaneous bleeding episodes within 12 weeks. Endpoints included annualized bleeding rate (ABR), adverse events (AEs), and occurrence of antidrug antibodies. Thromboembolic events were AEs of special interest. Thirty-six patients with HA, 15 with HAwI, and 10 with HBwI were exposed to concizumab. Estimated ABRs during the main 1 extension parts at last dose level were 4.8 (95% confidence interval [CI], 3.2-7.2) and 6.4 (95% CI, 4.1-9.9) in explorer4 and explorer5, respectively (spontaneous ABRs were 1.8 [95% CI, 1.2-2.6] and 2.1 [95% CI, 1.3-3.3]). Most AEs were mild, with no deaths, events leading to withdrawal, or thromboembolic events. Anti-drug antibodies developed in 25% of patients and were low titer and transient, with no observed clinical effect in most cases. Results of the main 1 extension parts of these trials were consistent with results of the main parts. Ongoing phase 3 trials will further evaluate concizumab as a once-daily, subcutaneous treatment across hemophilia subtypes.
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| 10. |
- Steen Carlsson, Katarina, et al.
(author)
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High use of pain, depression, and anxiety drugs in hemophilia: more than 3000 people with hemophilia in an 11-year Nordic registry study
- 2023
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In: Research and Practice in Thrombosis and Haemostasis. - : Elsevier BV. - 2475-0379. ; 7:2
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Journal article (peer-reviewed)abstract
- Background: Pain is a common feature of hemophilia, but prevalence of depression and anxiety is less studied. Registry data on prescription drugs can provide an objective measure of the magnitude of these complications. Objectives: To identify treatment patterns of prescribed pain, antidepressant, and antianxiety medications compared with those of matched controls in 4 Nordic countries. Methods: The MIND study (NCT03276130) analyzed longitudinal individual-level national data during 2007-2017. People with hemophilia (PwH) were identified from National Health Data Registers by diagnosis or factor replacement treatment and compared with population controls. Three subgroups were defined by the use of factor concentrates and sex (moderate-to-high factor consumption (factor VIII [FVIII] use of ≥40 IU/kg/week or FIX use of ≥10 IU/kg/week), low factor consumption, and women including carriers). Results: Data of 3246 PwH, representing 30,184 person-years, were analyzed. PwH (including children and adults) used more pain, depression, and anxiety medications compared with controls. This was most accentuated in the moderate-to-high factor consumption group and notably also observed in men with low factor consumption and women including carriers, usually representing a milder phenotype. A higher opioid use was observed across all age groups: 4- to 6-fold higher in the moderate-to-high factor consumption group and 2- to 4-fold higher in the low factor consumption group. Conclusion: The consistent higher use of pain, depression, and anxiety medications among PwH compared with population controls, regardless of age, sex, or factor consumption, in broad national data suggests a need for improved bleed protection and hemophilia care for all severities including mild hemophilia.
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