Childhood immune thrombocytopenia (ITP) is a rare autoimmune disorder characterized by isolated thrombocytopenia. Prolonged ITP (persistent and chronic) leads to a reduced quality of life for ...children in many domains. To provide optimal support for children, with ITP, it is important to be able to predict those who will develop prolonged ITP. This study aimed to develop a mathematical model based on platelet recovery that allows the early prediction of prolonged ITP. In this retrospective study, we used platelet counts from the 6 months following the diagnosis of ITP to model the kinetics of change in platelet count using a pharmacokinetic–pharmacodynamic model. In a learning set (n = 103), platelet counts were satisfactorily described by our kinetic model. The Kheal parameter, which describes spontaneous platelet recovery, allowed a distinction between acute and prolonged ITP with an area under the curve (AUC) of 0.74. In a validation set (n = 58), spontaneous platelet recovery was robustly predicted using platelet counts from 15 (AUC = 0.76) or 30 (AUC = 0.82) days after ITP diagnosis. In our model, platelet recovery quantified using the kheal parameter allowed prediction of the clinical course of ITP. Future prospective studies are needed to improve the predictivity of this model, in particular, by combining it with the predictive scores previously reported in the literature.
Objective To assess school performance in an unselected group of childhood cancer survivors and study risk factors for impairment. Study design Rates of repeating a grade were compared for patients ...with cancer, their siblings, and the general population. Phone questionnaires were administered to patients about the school career of their child in remission and their siblings. Responses about cancer survivors were compared with those concerning their siblings and various registries provided by the national board of education. The primary outcome was the rate of repeating a grade. Results A total of 148 children in remission with a mean age of 15 ± 5.3 years and a mean follow-up period since diagnosis of 6.3 ± 1.3 years were included. More patients than siblings repeated a grade (33% versus 21%; P = .02), with a mean delay since diagnosis of 2 years. Risk factors were an older age at diagnosis, attending a secondary school, low education level of parents, bone marrow transplantation, cerebral surgery, and physical sequelae. In multivariate analysis, risk for repeating was associated with low educational level of the father, attending secondary school at diagnosis, and requiring school-organized educational support on return to school. Conclusion After cancer, repeating a grade is not an exceptional occurrence, especially for teenagers; follow-up and supportive interventions before returning to school would be beneficial.
Von Willebrand disease (VWD) is the most common inherited bleeding disorder. However, studies of hospitalisation patterns with replacement treatment are scarce.
The aim of this study was to ...investigate the current therapeutic management of VWD and determine the key drivers of coagulation factor uses in patients during hospitalisation.
Hopscotch-WILL was a multi-centric retrospective study conducted over a 48-month period in any patients with VWD. The data were collected from the BERHLINGO Research Database and the French Hospital database.
A total of 988 patients were included; 153 patients (15%) were hospitalised during 293 stays requiring treatment with von Willebrand factor (VWF) concentrates-pure or in association with Factor VIII (FVIII). Their median basal concentrations of VWF and FVIII were significantly lower than in untreated patients: VWF antigen < 30 IU/dL, VWF activity < 20 IU/dL and FVIII:C < 40 IU/dL. The median (interquartile range) concentrate consumption was similar between highly purified VWF or VWF combined with FVIII (72 110 vs 57 89 IU/kg/stay, p = 0.154). The use of VWF was highly heterogeneous by VWD type; type 3 had a particularly high impact on VWF consumption in non-surgical situations. The main admissions were for ear/nose/throat, hepato-gastroenterology, and trauma/orthopaedic conditions, besides gynaecological-obstetric causes in women.
The use of VWF concentrates is mostly influenced by low basal levels of VWF and FVIII, but also by VWD type or the cause for hospitalisation. These results could inform future studies of newly released recombinant VWF.
The recent development of a humanized, bi-specific, and monoclonal antibody mimicking the function of activated factor VIII was a revolution in the management of patients suffering from severe ...hemophilia A with inhibitors. The phase III randomized studies have shown a more efficient prophylaxis of this subcutaneous administered drug in these patients compared with recombinant FVIIa (rFVIIa) and activated prothrombin complex concentrates (aPCC). Nonetheless, there are “real life” matters that need to be explored in this new era of managing hemophilia patients, such as surgery management under emicizumab, especially in children. Here, we report the first case, to our knowledge, of major orthopedic surgery managed with factor VIII infusions in a child with inhibitor receiving emicizumab.
Introduction
Factor X deficiency is a rare inherited bleeding disorder. To date, 181 variants are reported in the recently updated F10‐gene variant database.
Aim
This study aimed to describe new F10 ...variants.
Method
The F10 gene was analysed in 16 consecutive families with FX deficiency by a targeted high‐throughput sequencing approach, including F10, F9, F8 genes, and 78 genes dedicated to haematological malignancies.
Results
We identified 19 variants (17 missense, one nonsense and one frameshift) and two copy number variations. Two patients presenting a combined FVII‐FX deficiency showed a loss of one F10 gene copy (del13q34) associated with a missense variant on the remaining allele, leading to a FX:C significantly lower than the FVII:C level and explaining their unusual bleeding history. We reported five novel variants. Three missense variants (p.Glu22Val affecting the signal peptide cleavage site, p.Cys342Tyr removing the disulphide bond between the FX heavy and light chains, and p.Val385Met located in FX peptidase S1 domain) were detected at compound heterozygosis status in three patients with severe bleeding symptoms and FX:C level below 10 IU/dL. Two truncating variants p.Tyr279* and p.Thr434Aspfs*13 leading to an altered FX protein were found at heterozygous state in two patients with mild bleeding history.
Conclusion
This study showed the feasibility and the interest of high‐throughput sequencing approach for rare bleeding disorders, enabling the report of F10 gene screening in a 3‐weeks delay, suitable for clinical use. The description of five new variants may contribute to a better understanding of the phenotype‐genotype correlation in FX deficiency.
Non-syndromic microcytic congenital sideroblastic anemia (cSA) is predominantly caused by defective genes encoding for either ALAS2, the first enzyme of heme biosynthesis pathway or SLC25A38, the ...mitochondrial importer of glycine, an ALAS2 substrate. Herein we explored a new case of cSA with two mutations in GLRX5, a gene for which only two patients have been reported so far. The patient was a young female with biallelic compound heterozygous mutations in GLRX5 (p.Cys67Tyr and p.Met128Lys). Three-D structure analysis confirmed the involvement of Cys67 in the coordination of the 2Fe2S cluster and suggested a potential role of Met128 in partner interactions. The protein-level of ferrochelatase, the terminal-enzyme of heme process, was increased both in patient-derived lymphoblastoid and CD34+ cells, however, its activity was drastically decreased. The activity of ALAS2 was found altered and possibly related to a defect in the biogenesis of its co-substrate, the succinyl-CoA. Thus, the patient exhibits both a very low ferrochelatase activity without any accumulation of porphyrins precursors in contrast to what is reported in erythropoietic protoporphyria with solely impaired ferrochelatase activity. A significant oxidative stress was evidenced by decreased reduced glutathione and aconitase activity, and increased MnSOD protein expression. This oxidative stress depleted and damaged mtDNA, decreased complex I and IV activities and depleted ATP content. Collectively, our study demonstrates the key role of GLRX5 in modulating ALAS2 and ferrochelatase activities and in maintaining mitochondrial function.
Summary
Constitutional thrombocytopenias are rare disorders, often difficult to discriminate from acquired thrombocytopenias. More than 80 genes have been described as being at the origin of these ...diseases. Among them, several variants of the glycoprotein Ib platelet subunit alpha (GP1BA) and glycoprotein Ib platelet subunit beta (GP1BB) genes, coding for the GpIb‐IX‐V glycoprotein complex, have been reported in the literature. The study reported here aimed at describing newly identified monoallelic anomalies affecting the GP1BA and GP1BB genes on a clinical, biological and molecular level. In a cohort of nine patients with macrothrombocytopenia, eight heterozygous variants of the GP1BA or GP1BB genes were identified. Five of them had never been described in the heterozygous state. Computer modelling disclosed structure/function relationships of these five variants.
Excessive bleeding at surgery is a feared complication in patients with inherited platelet disorders. However, very few studies have evaluated the frequency of surgical bleeding in these hemorrhagic ...disorders. We performed a worldwide, multicentric, retrospective study to assess the bleeding complications of surgery, the preventive and therapeutic approaches adopted, and their efficacy in patients with inherited platelet disorders: the Surgery in Platelet disorders And Therapeutic Approach (SPATA) study. We rated the outcome of 829 surgical procedures carried out in 423 patients with well-defined forms of inherited platelet disorders: 238 inherited platelet function disorders and 185 inherited platelet number disorders. Frequency of surgical bleeding was high in patients with inherited platelet disorders (19.7%), with a significantly higher bleeding incidence in inherited platelet function disorders (24.8%) than in inherited platelet number disorders (13.4%). The frequency of bleeding varied according to the type of inherited platelet disorder, with biallelic Bernard Soulier syndrome having the highest occurrence (44.4%). Frequency of bleeding was predicted by a pre-operative World Health Organization bleeding score of 2 or higher. Some types of surgery were associated with a higher bleeding incidence, like cardiovascular and urological surgery. The use of pre-operative pro-hemostatic treatments was associated with a lower bleeding frequency in patients with inherited platelet function disorders but not in inherited platelet number disorders. Desmopressin, alone or with antifibrinolytic agents, was the preventive treatment associated with the lowest bleedings. Platelet transfusions were used more frequently in patients at higher bleeding risk. Surgical bleeding risk in inherited platelet disorders is substantial, especially in inherited platelet function disorders, and bleeding history, type of disorder, type of surgery and female sex are associated with higher bleeding frequency. Prophylactic pre-operative pro-hemostatic treatments appear to be required and are associated with a lower bleeding incidence.
PDF
