COVID-19 vaccination in patients with immune thrombocytopenia

Immune thrombocytopenia (ITP) is an acquired autoimmune disorder characterized by low platelet count and increased bleeding risk. COVID-19 vaccination has been described as risk factor for de novo ITP, but the effects of COVID-19 vaccination in patients with ITP are unknown. Our aims were to investigate the effects of COVID-19 vaccination in ITP patients on platelet count, bleeding complications and ITP exacerbation (any of: ≥50% decline in platelet count; or nadir platelet count 20% decrease from baseline; or use of rescue therapy). Platelet counts of ITP patients and healthy controls were collected immediately before, 1 and 4 weeks after first and second vaccination. Linear mixed-effects modelling was applied to analyze platelet counts over time. We included 218 ITP patients (50.9% female, mean age 55 years and median platelet count of 106x109/L) and 200 healthy controls (60.0% female, mean age 58 years and median platelet count of 256x109/L). Platelet counts decreased by 6.3% after vaccination. We observed no difference in decrease between the groups. Thirty ITP patients (13.8%, 95%CI 9.5%-19.1%) had an exacerbation and 5 (2.2%, 95%CI 0.7%-5.3%) suffered from a bleeding event. Risk factors for ITP exacerbation were platelet count <50x109/L (OR 5.3, 95%CI 2.1-13.7), ITP treatment at time of vaccination (OR 3.4, 95%CI 1.5-8.0) and age (OR 0.96 per year, 95%CI 0.94-0.99). Our study highlights safety of COVID-19 vaccination in ITP patients and importance of close monitoring platelet counts in a subgroup of ITP patients. ITP patients with exacerbation responded well on therapy

A new population pharmacokinetic model for recombinant factor IX‐Fc fusion concentrate including young children with haemophilia B

Aims: Recombinant factor IX Fc fusion protein (rFIX‐Fc) is an extended half‐life factor concentrate administered to haemophilia B patients. So far, a population pharmacokinetic (PK) model has only been published for patients aged ≥12 years. The aim was to externally evaluate the predictive performance of the published rFIX‐Fc population PK model for patients of all ages and develop a model that describes rFIX‐Fc PK using real‐world data. Methods: We collected prospective and retrospective data from patients with haemophilia B treated with rFIX‐Fc and included in the OPTI‐CLOT TARGET study (NTR7523) or United Kindom (UK)‐EHL Outcomes Registry (NCT02938156). Predictive performance was assessed by comparing predicted with observed FIX activity levels. A new population PK model was constructed using nonlinear mixed‐effects modelling. Results: Real‐world data were obtained from 37 patients (median age: 16 years, range 2–71) of whom 14 were aged <12 years. Observed FIX activity levels were significantly higher than levels predicted using the published model, with a median prediction error of −48.8%. The new model showed a lower median prediction error (3.4%) and better described rFIX‐Fc PK, especially for children aged <12 years. In the new model, an increase in age was correlated with a decrease in clearance (P < .01). Conclusions: The published population PK model significantly underpredicted FIX activity levels. The new model better describes rFIX‐Fc PK, especially for children aged <12 years. This study underlines the necessity to strive for representative population PK models, thereby avoiding extrapolation outside the studied population

Acute effect of pegvisomant on cardiovascular risk markers in healthy men: Implications for the pathogenesis of atherosclerosis in GH deficiency

Cardiovascular risk is increased in GH deficiency (GHD). GHD adults are frequently abdominally obese and display features of the metabolic syndrome. Otherwise healthy abdominally obese subjects have low GH levels and show features of the metabolic syndrome as well. We investigated in healthy nonobese males the effect of the GH receptor antagonist pegvisomant in different metabolic conditions. This is a model for acute GHD without the alterations in body composition associated with GHD. We compared the effect of pegvisomant with that of placebo before and after 3 d of fasting. In addition, we investigated the effect of pegvisomant under normal, i.e. fed, conditions. Three days of fasting as well as pegvisomant alone decreased serum free IGF-I levels (1.0 ± 0.15 vs. 0.31 ± 0.05 ng/ml and 0.86 ± 0.23 vs. 0.46 ± 0.23 ng/ml, respectively). Fasting in combination with pegvisomant also decreased serum free IGF-I levels (1.0 ± 0.15 vs. 0.31 ± 0.07 ng/ml), Treatment with pegvisomant had no additional influence on the decline of free IGF-I induced by fasting. Pegvisomant alone had no influence on insulin sensitivity. The increase in insulin sensitivity induced by fasting was comparable to the increase in insulin sensitivity induced by fasting combined with pegvisomant. Among serum lipid concentrations, only serum triglycerides increased significantly as a result of pegvisomant alone (1.0 ± 0.2 vs. 1.6 ± 0.4 mmol/liter). The changes in lipid concentrations induced by fasting alone or pegvisomant were not different from those induced by pegvisomant alone, von Wille-brand factor antigen levels declined significantly under the influence of pegvisomant alone (1.1 ± 0.07 vs. 0.8 ± 0.06 U/ml). In conclusion, in different metabolic conditions the GH receptor antagonist pegvisomant induces no significant acute changes in the major risk markers for cardiovascular disease. These data suggest that the secondary metabolic changes, e.g. abdominal obesity or inflammatory factors, that develop as a result of long-standing GHD are of primary importance in the pathogenesis of atherosclerosis in patients with GHD

E-learning improves knowledge and practical skills in haemophilia patients on home treatment:A randomized controlled trial

Home treatment of haemophilia is currently the standard of care for patients with severe haemophilia. Home treatment increases the responsibility of the patients for their own treatment and care. Therefore, it is of utmost importance to attain a high level of knowledge and practical skills. The aim of our study was to investigate whether or not an educational e-learning program improves knowledge and skills of adult patients with haemophilia on home treatment. Participants treated at the Haemophilia Treatment Center of the Erasmus University Medical Centre completed a questionnaire to test their knowledge of haemophilia, treatment of bleedings and of complications of treatment and were observed during the intravenous injection of clotting factor concentrate, using a standardized scoring list. Afterwards they were randomized to follow an e-learning program or no intervention (control group). After 1month they completed the same questionnaire again and practical skills were scored once more. At baseline, haemophilia patients (n=30) scored 24 of 48 questions in the questionnaire correctly. Seventy-five per cent of the items on the practical skills scoring list were performed correctly. One month later, the e-learning group (n=16; 36; 18-45) showed a higher level of theoretical knowledge compared to the control group (n=14; 26; 19-32; P&lt;0.001). Also practical skills were significantly better in the group that followed the e-learning program compared to the control group (respectively P=0.002). Self-efficacy of 90% vs. 80% the patients with haemophilia was high in all patients. Our study shows that in haemophilia patients with haemophilia, who are on home treatment, knowledge of haemophilia treatment and complications as well as practical skills can be improved by an educational e-learning program.</p