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2.
Haematologica ; 2021 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-33440924

RESUMO

Pediatric-onset Evans syndrome (pES) is defined by both immune thrombocytopenic purpura (ITP) and autoimmune hemolytic anemia (AIHA) before the age of 18 years. There have been no comprehensive long-term studies of this rare disease, which can be associated to various immunopathological manifestations (IMs). We report outcomes of the 151 patients with pES and more than 5 years of follow-up from the nationwide French prospective OBS'CEREVANCE cohort. Median age at final follow-up was 18.5 (6.8-50.0) years and the median follow-up period was 11.3 (5.1-38.0) years. At 10 years, ITP and AIHA were in sustained complete remission in 54.5% and 78.4% of patients, respectively. The frequency and number of clinical and biological IMs increased with age: at 20 years old, 74% had at least one clinical cIM. A wide range of cIMs occurred, mainly lymphoproliferation, dermatological, gastrointestinal/hepatic and pneumological IMs. The number of cIMs was associated with a subsequent increase in the number of second-line treatments received (other than steroids and immunoglobulins; hazard ratio, 1.4; 95% confidence interval, 1.15-1.60; p = 0.0002, Cox proportional hazards method). Survival at 15 years after diagnosis was 84%. Death occurred at a median age of 18 (1.7-31.5) years, and the most frequent cause was infection. The number of second-line treatments and severe/recurrent infections were independently associated with mortality. In conclusion, longterm outcomes of pES showed remission of cytopenias but frequent IMs linked to high secondline treatment burden. Mortality was associated to drugs and/or underlying immunodeficiencies, and adolescents-young adults are a high-risk subgroup.

3.
J Pediatr ; 2020 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-33340549

RESUMO

OBJECTIVE: To describe 4 subgroups of pediatric patients treated with splenectomy, hydroxychloroquine, azathioprine, or rituximab as the first-option, second-line treatment for chronic immune thrombocytopenia. STUDY DESIGN: Selection of patients with chronic immune thrombocytopenia from the French national prospective cohort of pediatric autoimmune cytopenia OBS'CEREVANCE and VIGICAIRE study, treated by splenectomy, hydroxychloroquine, azathioprine, or rituximab as a first second-line treatment. RESULTS: For 137 patients, treated between 1989 and 2016, the median follow-up after diagnosis and after treatment initiation was 8.5 (2.8-26.4) years and 4.7 (1.1-25.1) years, respectively. Median age at diagnosis and at initiation of treatment were 9 (0.7; 16) and 12 (2; 18.1) years, respectively without significant difference between subgroups. For the whole cohort, 24-month event-free survival was 62% (95% CI 55; 71). It was 85% (95% CI 77; 95) for the 56 patients treated with splenectomy, 60% (95% CI 44; 84) for the 23 patients treated with rituximab, 46% (95% CI 30; 71) for the 24 patients treated with azathioprine, and 37% (95% CI 24; 59) for the 34 patients treated with hydroxychloroquine (log-rank P < .0001). For the splenectomy subgroup, being older than 10 years at splenectomy tended to improve event-free survival (P = .05). Female teenagers with antinuclear antibody positivity benefited from hydroxychloroquine therapy. CONCLUSIONS: This national study, limiting pitfalls in the analysis of the effects of second-line therapies, showed that splenectomy remains the treatment associated with the better response at 24 months.

4.
Br J Haematol ; 2020 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-33216975

RESUMO

We report here the 3-year stenosis outcome in 60 stroke-free children with sickle cell anaemia (SCA) and an abnormal transcranial Doppler history, enrolled in the DREPAGREFFE trial, which compared stem cell transplantation (SCT) with standard-care (chronic transfusion for 1-year minimum). Twenty-eight patients with matched sibling donors were transplanted, while 32 remained on standard-care. Stenosis scores were calculated after performing cerebral/cervical 3D time-of-flight magnetic resonance angiography. Fourteen patients had stenosis at enrollment, but only five SCT versus 10 standard-care patients still had stenosis at 3 years. Stenosis scores remained stable on standard-care, but significantly improved after SCT (P = 0·006). No patient developed stenosis after SCT, while two on standard-care did, indicating better stenosis prevention and improved outcome after SCT.

5.
Arthritis Rheumatol ; 2020 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-32779863

RESUMO

OBJECTIVE: Anakinra has been shown to be successful in preventing and treating cardiovascular lesions both in experimental murine models of Kawasaki disease (KD) and in several studies of intravenous immunoglobulin (IVIG)- and steroid-resistant patients with KD. This study was undertaken to determine the safety of blocking interleukin-1 in patients with IVIG-resistant KD. METHODS: Sixteen patients were included in the present study. Patients with KD who were not responsive to 1 or more courses of 2 mg/kg of IVIG received anakinra by subcutaneous daily injections. The starting dose was 2 mg/kg of anakinra (4 mg/kg in patients who were age <8 months and who weighed ≥5 kilograms), and the dose was increased up to 6 mg/kg every 24 hours if the patient's body temperature remained >38°C, indicative of a fever. Treatment duration was 14 days. The last visit was on day 45. The primary outcome was abatement of fever. Secondary outcome measures included disease activity, coronary artery Z score, and C-reactive protein (CRP) levels. RESULTS: Seventy-five percent of the patients in the intent-to-treat group and 87.5% in the per-protocol group became afebrile within 48 hours of the last escalation dose of anakinra. Reduction of disease activity by 50% was indicated on 93.3% of physician evaluations (95% confidence interval [95% CI] 68.1-99.8%) and on 100% of parent evaluations (95% CI 73.5-100%) of parent evaluations. CRP values normalized by day 30. At the initial screening, 12 of 16 patients had a maximum coronary artery Z score of >2, and 10 of 16 patients had a maximum Z score of >2.5. On day 45, 5 of 10 patients (50% [95% CI 18.7-81.3%]) and 6 of 12 patients (50% [95% CI 21.1-78.9%]) had achieved coronary artery Z scores of <2.5 and <2, respectively. Five serious adverse events were observed in 3 patients, but no serious infections or deaths occurred. CONCLUSION: Anakinra was well tolerated in the study patients and may have some efficacy in reducing fever, markers of systemic inflammation, and coronary artery dilatation in individuals with IVIG-refractory KD.

6.
Clin Chem Lab Med ; 2020 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-32813673

RESUMO

Objectives Newborn screening (NBS) for ß-thalassemia is based on measuring the expression of the hemoglobin A (HbA) fraction. An absence or very low level of HbA at birth may indicate ß-thalassemia. The difficulty is that the HbA fraction at birth is correlated with gestational age (GA) and highly variable between individuals. We used HbA expressed in multiples of the normal (MoM) to evaluate relevant thresholds for NBS of ß-thalassemia. Methods The chosen threshold (HbA≤0.25 MoM) was prospectively applied for 32 months in our regional NBS program for sickle cell disease, for all tests performed, to identify patients at risk of ß-thalassemia. Reliability of this threshold was evaluated at the end of the study. Results In all, 343,036 newborns were tested, and 84 suspected cases of ß-thalassemia were detected by applying the threshold of HbA≤0.25 MoM. Among the n=64 cases with confirmatory tests, 14 were confirmed using molecular analysis as ß-thalassemia diseases, 37 were confirmed as ß-thalassemia trait and 13 were false-positive. Determination of the optimum threshold for ß-thalassemia screening showed that HbA≤0.16 MoM had a sensitivity of 100% and a specificity of 95.3%, whatever the GA. Conclusions NBS for ß-thalassemia diseases is effective, regardless of the birth term, using the single robust threshold of HbA≤0.16 MoM. A higher threshold would also allow screening for carriers, which could be interesting when ß-thalassemia constitutes a public health problem.

7.
Orphanet J Rare Dis ; 15(1): 180, 2020 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-32641076

RESUMO

BACKGROUND: Congenital hemolytic anemia constitutes a heterogeneous group of rare genetic disorders of red blood cells. Diagnosis is based on clinical data, family history and phenotypic testing, genetic analyses being usually performed as a late step. In this study, we explored 40 patients with congenital hemolytic anemia by whole exome sequencing: 20 patients with hereditary spherocytosis and 20 patients with unexplained hemolysis. RESULTS: A probable genetic cause of disease was identified in 82.5% of the patients (33/40): 100% of those with suspected hereditary spherocytosis (20/20) and 65% of those with unexplained hemolysis (13/20). We found that several patients carried genetic variations in more than one gene (3/20 in the hereditary spherocytosis group, 6/13 fully elucidated patients in the unexplained hemolysis group), giving a more accurate picture of the genetic complexity of congenital hemolytic anemia. In addition, whole exome sequencing allowed us to identify genetic variants in non-congenital hemolytic anemia genes that explained part of the phenotype in 3 patients. CONCLUSION: The rapid development of next generation sequencing has rendered the genetic study of these diseases much easier and cheaper. Whole exome sequencing in congenital hemolytic anemia could provide a more precise and quicker diagnosis, improve patients' healthcare and probably has to be democratized notably for complex cases.

8.
Kidney Int Rep ; 5(3): 348-357, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32154456

RESUMO

Introduction: Anion exchanger 1 (AE1) (SLC4A1 gene product) is a membrane protein expressed in both kidney and red blood cells (RBCs): it exchanges extracellular bicarbonate (HCO3 -) for intracellular chloride (Cl-) and participates in acid-base homeostasis. AE1 mutations in kidney α-intercalated cells can lead to distal renal tubular acidosis (dRTA). In RBC, AE1 (known as band 3) is also implicated in membrane stability: deletions can cause South Asian ovalocytosis (SAO). Methods: We retrospectively collected clinical and biological data from patients harboring dRTA due to a SLC4A1 mutation and analyzed HCO3 - and Cl- transports (by stopped-flow spectrophotometry) and expression (by flow cytometry, fluorescence activated cell sorting, and Coomassie blue staining) in RBCs, as well as RBC membrane stability (ektacytometry). Results: Fifteen patients were included. All experience nephrolithiasis and/or nephrocalcinosis, 2 had SAO and dRTA (dRTA SAO+), 13 dominant dRTA (dRTA SAO-). The latter did not exert specific RBC membrane anomalies. Both HCO3 - and Cl- transports were lower in patients with dRTA SAO+ than in those with dRTA SAO- or controls. Using 3 different extracellular probes, we report a decreased expression (by 52%, P < 0.05) in dRTA SAO+ patients by fluorescence activated cell sorting, whereas total amount of protein was not affected. Conclusion: Band 3 transport function and expression in RBCs from dRTA SAO- patients is normal. However, in SAO RBCs, impaired conformation of AE1/band 3 corresponds to an impaired function. Thus, the driver of acid-base defect during dominant dRTA is probably an impaired membrane expression.

9.
Br J Haematol ; 189(5): 931-942, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32130726

RESUMO

Childhood chronic immune thrombocytopenic purpura (cITP) is a rare disease. In severe cases, there is no evidence for the optimal therapeutic strategy. Our aim was to describe the real-life management of non-selected children with cITP at diagnosis. Since 2004, patients less than 18 years old with cITP have been enrolled in the national prospective cohort, OBS'CEREVANCE. From 1990 to 2014, in 29 centres, 392 children were diagnosed with cITP. With a median follow-up of six years (2·0-25), 45% did not need second-line therapy, and 55% (n = 217) received one or more second lines, mainly splenectomy (n = 108), hydroxychloroquine (n = 61), rituximab (n = 61) or azathioprine (n = 40). The overall five-year further second-line treatment-free survival was 56% [95% CI 49·5-64.1]. The use of splenectomy significantly decreased over time. Hydroxychloroquine was administered to children with positive antinuclear antibodies, more frequently older and girls, and reached 55% efficacy. None of the patients died. Ten years after the initial diagnosis, 55% of the 56 followed children had achieved complete remission. Children with cITP do not need second-line treatments in 45% of cases. Basing the treatment decision on the pathophysiological pathways is challenging, as illustrated by ITP patients with positive antinuclear antibodies treated with hydroxychloroquine.

10.
Haematologica ; 105(3): 610-622, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31413092

RESUMO

Hereditary xerocytosis is a dominantly inherited red cell membrane disorder caused in most cases by gain-of-function mutations in PIEZO1, encoding a mechanosensitive ion channel that translates a mechanic stimulus into calcium influx. We found that PIEZO1 was expressed early in erythroid progenitor cells, and investigated whether it could be involved in erythropoiesis, besides having a role in the homeostasis of mature red cell hydration. In UT7 cells, chemical PIEZO1 activation using YODA1 repressed glycophorin A expression by 75%. This effect was PIEZO1-dependent since it was reverted using specific short hairpin-RNA knockdown. The effect of PIEZO1 activation was confirmed in human primary progenitor cells, maintaining cells at an immature stage for longer and modifying the transcriptional balance in favor of genes associated with early erythropoiesis, as shown by a high GATA2/GATA1 ratio and decreased α/ß-globin expression. The cell proliferation rate was also reduced, with accumulation of cells in G0/G1 of the cell cycle. The PIEZO1-mediated effect on UT7 cells required calcium-dependent activation of the NFAT and ERK1/2 pathways. In primary erythroid cells, PIEZO1 activation synergized with erythropoietin to activate STAT5 and ERK, indicating that it may modulate signaling pathways downstream of erythropoietin receptor activation. Finally, we studied the in-vitro erythroid differentiation of primary cells obtained from 14 PIEZO1-mutated patients, from 11 families, carrying ten different mutations. We observed a delay in erythroid differentiation in all cases, ranging from mild (n=3) to marked (n=8). Overall, these data demonstrate a role for PIEZO1 during erythropoiesis, since activation of PIEZO1 - both chemically and through activating mutations - delays erythroid maturation, providing new insights into the pathophysiology of hereditary xerocytosis.

11.
Blood Adv ; 3(15): 2328-2336, 2019 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-31391165

RESUMO

Spleen dysfunction is central to morbidity and mortality in children with sickle cell anemia (SCA). The initiation and determinants of spleen injury, including acute splenic sequestration (ASS) have not been established. We investigated splenic function longitudinally in a cohort of 57 infants with SCA enrolled at 3 to 6 months of age and followed up to 24 months of age and explored the respective contribution of decreased red blood cell (RBC) deformability and increased RBC adhesion on splenic injury, including ASS. Spleen function was evaluated by sequential 99mTc heated RBC spleen scintigraphy and high-throughput quantification of RBCs with Howell-Jolly bodies (HJBs). At 6 and 18 months of age, spleen filtration function was decreased in 32% and 50% of infants, respectively, whereas the median %HJB-RBCs rose significantly (from 0.3% to 0.74%). An excellent correlation was established between %HJB-RBCs and spleen scintigraphy results. RBC adhesion to laminin and endothelial cells increased with time. Adhesion to endothelial cells negatively correlated with splenic function. Irreversibly sickled cells (ISCs), used as a surrogate marker of impaired deformability, were detected at enrollment and increased significantly at 18 months. %ISCs correlated positively with %HJB-RBCs and negatively with splenic uptake, indicating a relationship between their presence in the circulation and spleen dysfunction. In the subgroup of 8 infants who subsequently experienced ASS, %ISCs at enrollment were significantly higher compared with the asymptomatic group, suggesting a major role of impaired deformability in ASS. Higher levels of %HJB-RBCs were observed after the occurrence of ASS, demonstrating its negative impact on splenic function.


Assuntos
Anemia Falciforme/complicações , Suscetibilidade a Doenças , Esplenopatias/diagnóstico , Esplenopatias/etiologia , Biomarcadores , Deformação Eritrocítica/efeitos dos fármacos , Inclusões Eritrocíticas/patologia , Feminino , Humanos , Imunofenotipagem , Incidência , Masculino , Fosforilação , Cintilografia/métodos , Esplenopatias/epidemiologia
12.
Haematologica ; 104(8): 1554-1564, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30655378

RESUMO

We describe the clinical, hematologic and genetic characteristics of a retrospective series of 126 subjects from 64 families with hereditary xerocytosis. Twelve patients from six families carried a KCNN4 mutation, five had the recurrent p.Arg352His mutation and one had a new deletion at the exon 7-intron 7 junction. Forty-nine families carried a PIEZO1 mutation, which was a known recurrent mutation in only one-third of the cases and private sequence variation in others; 12 new probably pathogenic missense mutations were identified. The two dominant features leading to diagnosis were hemolysis that persisted after splenectomy and hyperferritinemia, with an inconstant correlation with liver iron content assessed by magnetic resonance imaging. PIEZO1-hereditary xerocytosis was characterized by compensated hemolysis in most cases, perinatal edema of heterogeneous severity in more than 20% of families and a major risk of post-splenectomy thrombotic events, including a high frequency of portal thrombosis. In KCNN4-related disease, the main symptoms were more severe anemia, hemolysis and iron overload, with no clear sign of red cell dehydration; therefore, this disorder would be better described as a 'Gardos channelopathy'. These data on the largest series to date indicate that PIEZO1-hereditary xerocytosis and Gardos channelopathy are not the same disease although they share hemolysis, a high rate of iron overload and inefficient splenectomy. They demonstrate the high variability in clinical expression as well as genetic bases of PIEZO1-hereditary xerocytosis. These results will help to improve the diagnosis of hereditary xerocytosis and to provide recommendations on the clinical management in terms of splenectomy, iron overload and pregnancy follow-up.


Assuntos
Anemia Hemolítica Congênita/genética , Canalopatias/genética , Hidropisia Fetal/genética , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/genética , Canais Iônicos/genética , Anemia Hemolítica Congênita/complicações , Anemia Hemolítica Congênita/cirurgia , Edema/etiologia , Família , Feminino , Hemólise , Humanos , Hidropisia Fetal/cirurgia , Sobrecarga de Ferro , Masculino , Mutação , Mutação de Sentido Incorreto , Gravidez , Estudos Retrospectivos , Esplenectomia/efeitos adversos , Trombose
13.
JAMA ; 321(3): 266-276, 2019 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-30667500

RESUMO

Importance: In children with sickle cell anemia (SCA), high transcranial Doppler (TCD) velocities are associated with stroke risk, which is reduced by chronic transfusion. Whether matched sibling donor hematopoietic stem cell transplantation (MSD-HSCT) can reduce velocities in patients with SCA is unknown. Objective: To determine the association of MSD-HSCT with TCD velocities as a surrogate for the occurrence of ischemic stroke in children with SCA. Design, Setting, and Participants: Nonrandomized controlled intervention study conducted at 9 French centers. Patients with SCA were enrolled between December 2010 and June 2013, with 3-year follow-up ending in January 2017. Children with SCA were eligible if younger than 15 years, required chronic transfusions for persistently elevated TCD velocities, and had at least 1 sibling without SCA from the same 2 parents. Families agreed to HLA antigen typing and transplantation if a matched sibling donor was identified or to standard care in the absence of a matched sibling donor. Exposures: MSD-HSCT (n = 32), compared with standard care (n = 35) (transfusions for ≥1 year with potential switch to hydroxyurea thereafter), using propensity score matching. Main Outcomes and Measures: The primary outcome was the highest time-averaged mean of maximum velocities in 8 cerebral arteries, measured by TCD (TCD velocity) at 1 year. Twenty-five of 29 secondary outcomes were analyzed, including the highest TCD velocity at 3 years and normalization of velocities (<170 cm/s) and ferritin levels at 1 and 3 years. Results: Sixty-seven children with SCA (median age, 7.6 years; 35 girls [52%]) were enrolled (7 with stroke history). In the matched sample, highest TCD velocities at 1 year were significantly lower on average in the transplantation group (129.6 cm/s) vs the standard care group (170.4 cm/s; difference, -40.8 cm/s [95% CI, -62.9 to -18.6]; P < .001). Of the 25 analyzed secondary end points, 4 showed significant differences, including the highest TCD velocity at 3 years (112.4 cm/s in the transplantation group vs 156.7 cm/s in the standard care group; difference, -44.3 [95% CI, -71.9 to -21.1]; P = .001); normalization rate at 1 year (80.0% in the transplantation group vs 48.0% in the standard care group; difference, 32.0% [95% CI, 0.2% to 58.6%]; P = .045); and ferritin levels at 1 year (905 ng/mL in the transplantation group vs 2529 ng/mL in the standard care group; difference, -1624 [95% CI, -2370 to -879]; P < .001) and 3 years (382 ng/mL in the transplantation group vs 2170 ng/mL in the standard care group; difference, -1788 [95% CI, -2570 to -1006]; P < .001). Conclusions and Relevance: Among children with SCA requiring chronic transfusion because of persistently elevated TCD velocities, MSD-HSCT was significantly associated with lower TCD velocities at 1 year compared with standard care. Further research is warranted to assess the effects of MSD-HSCT on clinical outcomes and over longer follow-up. Trial Registration: ClinicalTrials.gov Identifier: NCT01340404.


Assuntos
Anemia Falciforme/terapia , Circulação Cerebrovascular/fisiologia , Transplante de Células-Tronco Hematopoéticas , Irmãos , Ultrassonografia Doppler Transcraniana , Aloenxertos , Anemia Falciforme/diagnóstico por imagem , Anemia Falciforme/fisiopatologia , Velocidade do Fluxo Sanguíneo , Criança , Feminino , Ferritinas/sangue , Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Masculino , Pontuação de Propensão , Qualidade de Vida , Condicionamento Pré-Transplante
14.
Am J Hematol ; 93(11): 1411-1419, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30132969

RESUMO

In order to identify very early prognostic factors that can provide insights into subsequent clinical complications, we performed a comprehensive longitudinal multi-center cohort study on 57 infants with sickle cell anemia (55 SS; 2 Sß°) during the first 2 years of life (ClinicalTrials.gov: NCT01207037). Time to first occurrence of a severe clinical event-acute splenic sequestration (ASS), vaso-occlusive (VOC) event requiring hospitalization, transfusion requirement, conditional/ abnormal cerebral velocities, or death-was used as a composite endpoint. Infants were recruited at a mean age of 4.4 ±1 months. Median follow-up was 19.4 months. During the study period, 38.6% of infants experienced ≥1 severe event: 14% ASS, 22.8% ≥ 1 VOC (median age: 13.4 and 12.8 months, respectively) and 33.3% required transfusion. Of note, 77% of the cohort was hospitalized, with febrile illness being the leading cause for admission. Univariate analysis of various biomarkers measured at enrollment showed that fetal hemoglobin (HbF) was the strongest prognostic factor of subsequent severe outcome. Other biomarkers measured at enrolment including absolute neutrophil or reticulocyte counts, expression of erythroid adhesion markers, % of dense red cells, cellular deformability or ϒ-globin genetic variants, failed to be associated with severe clinical outcome. Multivariate analysis demonstrated that higher Hb concentration and HbF level are two independent protective factors (adjusted HRs (95% CI) 0.27 (0.11-0.73) and 0.16 (0.06-0.43), respectively). These findings imply that early measurement of HbF and Hb levels can identify infants at high risk for subsequent severe complications, who might maximally benefit from early disease modifying treatments.


Assuntos
Anemia Falciforme/diagnóstico , Índice de Gravidade de Doença , Anemia Falciforme/complicações , Anemia Falciforme/terapia , Biomarcadores/análise , Transfusão de Sangue , Estudos de Coortes , Feminino , Hemoglobina Fetal/análise , Hemoglobinas/análise , Hospitalização , Humanos , Lactente , Estudos Longitudinais , Masculino , Prognóstico
16.
Contemp Clin Trials ; 62: 91-104, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28821470

RESUMO

BACKGROUND: Children with sickle cell anemia (SCA) have an 11% risk of stroke by the age of 18. Chronic transfusion applied in patients detected to be at risk by transcranial Doppler allows a significant reduction of stroke risk. However, chronic transfusion exposes to several adverse events, including alloimmunization and iron overload, and is not curative. Hematopoietic stem cell transplantation allows termination of the transfusion program, but its benefit has not been demonstrated. DESIGN: DREPAGREFFE (NCT01340404) is a multicenter, prospective trial enrolling SCA children younger than 15years receiving chronic transfusion due to a history of abnormal transcranial Doppler (velocities ≥200cm/s). Only those with at least one non-SCA sibling and parents accepting HLA-typing and transplantation with a genoidentical donor were eligible. Chronic transfusion was pursued in patients with no available donor, whereas others were transplanted. Comparison between the 2 arms (transfusion vs transplantation) was analyzed using both genetic randomization and propensity-score matching as a sensitivity analysis. The primary end-point was the velocity measure at 1year. Secondary endpoints were the incidence of stroke, silent cerebral infarcts and stenoses, cognitive performance in comparison with siblings, allo-immunization, iron-overload, phosphatidyl-serine, angiogenesis/hypoxia, brain injury-related factor expression, quality of life and cost. OBJECTIVES: To show that genoidentical transplantation decreases velocities significantly more than chronic transfusion in SCA children at risk of stroke. DISCUSSION: DREPAGREFFE is the first prospective study to evaluate transplantation in SCA children. It compares the outcome of cerebral vasculopathy following genoidentical transplantation versus chronic transfusion using genetic randomization and causal inference methods.


Assuntos
Anemia Falciforme/complicações , Anemia Falciforme/terapia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Transplante de Células-Tronco Hematopoéticas/métodos , Acidente Vascular Cerebral/etiologia , Reação Transfusional , Adolescente , Transfusão de Sangue/economia , Transfusão de Sangue/métodos , Criança , Pré-Escolar , Cognição , Feminino , Transplante de Células-Tronco Hematopoéticas/economia , Humanos , Sobrecarga de Ferro/etiologia , Masculino , Estudos Prospectivos , Qualidade de Vida , Projetos de Pesquisa , Acidente Vascular Cerebral/diagnóstico por imagem , Ultrassonografia Doppler Transcraniana
18.
Br J Haematol ; 177(5): 751-758, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28444729

RESUMO

Childhood autoimmune haemolytic anaemia (AIHA) requires second-line immunosuppressive therapy in 30-50% of cases. It appears that rituximab is indicated in such circumstances. This prospective national study reports the practice, efficacy and tolerance of rituximab in children with isolated AIHA and AIHA in the setting of Evans syndrome (ES). Sixty-one children were given rituximab between 2000 and 2014. The median interval from diagnosis to rituximab was 9·9 [interquartile range (IQR) 1·6-28·5] months. Forty-six patients responded (75%) and the 6-year relapse-free survival (RFS) was 48%. Twenty patients relapsed at a median interval of 10·8 (IQR 3·9-18·7) months, rituximab allowed steroid withdrawal in 44/61 (72%) of children. In isolated AIHA, complete response and 6-year RFS were significantly higher than in ES (P < 0·05). Ten out of 61 patients were infants, seven of who responded with a 6-year RFS of 71%. Among patients without immunoglobulin substitution before rituximab, 4 are still receiving substitutions. Five patients died, including one potentially attributable to rituximab. This large observational series of childhood AIHA established the rituximab benefit-risk ratio, allowing steroid withdrawal, with 37% of long-term responders, mainly in isolated AIHA. All subgroups of patients drew benefit. Our long-term results indicate the baseline to be challenged by new treatment approaches.


Assuntos
Anemia Hemolítica Autoimune/tratamento farmacológico , Hematínicos/uso terapêutico , Rituximab/uso terapêutico , Adolescente , Transfusão de Sangue/estatística & dados numéricos , Criança , Pré-Escolar , Substituição de Medicamentos , Feminino , França , Humanos , Masculino , Estudos Prospectivos , Esteroides/uso terapêutico , Resultado do Tratamento
19.
Pediatr Blood Cancer ; 64(7)2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27905681

RESUMO

OBJECTIVES: Nationwide prospective cohort study exploring (i) the factors associated with treatment initiation (vs. watchful waiting) in children with primary immune thrombocytopenia (ITP) followed in routine clinical practice and (ii) the predictors of chronicity at 12 months. PROCEDURE: Between 2008 and 2013, 23 centers throughout France consecutively included 257 children aged 6 months-18 years and diagnosed with primary ITP over a 5-year period. Data on ITP clinical features along with medical management were collected at baseline and 12 months. Multivariate logistic regressions were used to determine (i) and (ii) as defined above, providing odds ratio (OR) with 95% confidence interval (95% CI). RESULTS: One hundred thirty-seven (53%) children were males, median age was 4.6 years, median platelet count was 7 × 109/l, and 214 (81%) patients initiated medication. Factors independently associated with treatment initiation included platelet counts <10 × 109/l (P < 0.0001) and mucocutaneous bleeding symptoms at baseline (P < 0.001). At 12 months, data were available for 211 (82%) children, of whom 160 (74%) had recovered. Predictors of chronicity included female gender (OR = 2.2; 95% CI = 1.0-4.8), age ≥10 years (OR = 2.6; 95% CI = 1.1-6.0), and platelet counts ≥10 × 109 /l (OR = 3.2; 95% CI = 1.5-6.9). CONCLUSIONS: In routine clinical practice, the decision to apply a watchful waiting strategy seems to be driven by platelet counts even in the absence of bleeding symptoms, resulting in treatment being initiated in more than 80% of the children surveyed. Overall, younger children with ITP showed good prognosis, with lower platelet counts and, to a lesser extent, male gender predicting more favorable outcomes.


Assuntos
Púrpura Trombocitopênica Idiopática/patologia , Púrpura Trombocitopênica Idiopática/terapia , Adolescente , Criança , Pré-Escolar , Estudos de Coortes , Feminino , França , Humanos , Lactente , Masculino , Razão de Chances , Contagem de Plaquetas , Resultado do Tratamento
20.
Thromb Haemost ; 116(6): 1070-1078, 2016 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-27683759

RESUMO

Interaction between von Willebrand factor (VWF) and platelet GPIbα is required for primary haemostasis. Lack or loss-of-function in the ligand-receptor pair results in bleeding complications. Paradoxically, gain-of-function mutations in VWF or GPIbα also result in bleeding complications as observed in type 2B von Willebrand disease (VWD) and platelet-type- (PT-) VWD, respectively. A similar phenotype is observed with increased ristocetin-induced platelet agglutination and disappearance of the highest molecular weight multimers of VWF. We evaluated a patient with a bleeding disorder and a biological presentation compatible with type 2B VWD. VWF and platelet functional assays, sequencing of the VWF and GP1BA genes, and expression studies in HEK cells were performed. Sequencing of the VWF gene in the propositus revealed a heterozygous p.Pro1266Leu mutation previously found in type 2B VWD Malmö/New York. These variants are characterised by a mild phenotype and a normal VWF multimer composition suggesting the presence of a second mutation in our propositus. Sequencing of the GP1BA gene revealed a heterozygous c.765G>A substitution changing Met at position 255 of GPIbα to Ile. This new mutation is located in the ß-switch domain where five other gain-of-function mutations have been reported in PT-VWD. Expression of GPIbα Ile255 in HEK GPIb-IX cells resulted in enhanced VWF binding compared to wild-type, similar to known PT-VWD mutations (p.Val249, p.Ser249 and p.Val255) indicating that it contributes to the propositus defects. This first report associating PT- with type 2B VWD illustrates the importance of combining biological assays with genetic testing to better understand the clinical phenotype.


Assuntos
Complexo Glicoproteico GPIb-IX de Plaquetas/genética , Doenças de von Willebrand/genética , Plaquetas , Criança , Feminino , Humanos , Masculino , Mutação , Fator de von Willebrand/genética
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