Marlène Pasquet

High frequency of GATA2 mutations in patients with mild chronic neutropenia evolving to MonoMac syndrome, myelodysplasia, and acute myeloid leukemia

UNLABELLED Congenital neutropenia is a group of genetic disorders that involve chronic neutropenia and susceptibility to infections. These neutropenias may be isolated or associated with immunologic defects or extra-hematopoietic manifestations. Complications may occur as infectious diseases, but also less frequently as myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML). Recently, the transcription factor GATA2 has been identified as a new predisposing gene for familial AML/MDS. In the present study, we describe the initial identification by exome sequencing of a GATA2 R396Q mutation in a family with a history of chronic mild neutropenia evolving to AML and/or MDS. The subsequent analysis of the French Severe Chronic Neutropenia Registry allowed the identification of 6 additional pedigrees and 10 patients with 6 different and not previously reportedGATA2 mutations (R204X, E224X, R330X, A372T, M388V, and a complete deletion of the GATA2 locus). The frequent evolution to MDS and AML in these patients reveals the importance of screening GATA2 in chronic neutropenia associated with monocytopenia because of the frequent hematopoietic transformation, variable clinical expression at onset, and the need for aggressive therapy in patients with poor clinical outcome. KEY POINTS Mutations of key transcription factor in myeloid malignancies.

Cutaneous and visceral chronic granulomatous disease triggered by a Rubella Virus vaccine strain in children with primary immunodeficiencies

Persistence of rubella live vaccine has been associated with chronic skin granuloma in 3 children with primary immunodeficiency. We describe 6 additional children with these findings, including 1 with visceral extension to the spleen.

Evans Syndrome in Children: Long-Term Outcome in a Prospective French National Observational Cohort

Evans syndrome (ES) is a rare autoimmune disorder whose long-term outcome is not well known. In France, a collaborative pediatric network set up via the National Rare Disease Plan now provides comprehensive clinical data in children with this disease. Patients aged less than 18 years at the initial presentation of autoimmune cytopenia have been prospectively included into a national observational cohort since 2004. The definition of ES was restricted to the simultaneous or sequential association of autoimmune hemolytic anemia (AIHA) and immune thrombocytopenic purpura (ITP). Cases were deemed secondary if associated with a primitive immunodeficiency or systemic lupus erythematosus. In December 2014, we analyzed the data pertaining to 156 children from 26 centers with ES whose diagnosis was made between 1981 and 2014. Median age (range) at the onset of cytopenia was 5.4 years (0.2–17.2). In 85 sequential cases, the time lapse between the first episodes of AIHA and ITP was 2.4 years (0.1–16.3). The follow-up period as from ES diagnosis was 6.5 years (0.1–28.8). ES was secondary, revealing another underlying disease, in 10% of cases; various associated immune manifestations (mainly lymphoproliferation, other autoimmune diseases, and hypogammaglobulinemia) were observed in 60% of cases; and ES remained primary in 30% of cases. Five-year ITP and AIHA relapse-free survival were 25 and 61%, respectively. Overall, 69% of children required one or more second-line immune treatments, and 15 patients (10%) died at the age of 14.3 years (1.7–28.1). To our knowledge, this is the first consistent long-term clinical description of this rare syndrome. It underscores the high rate of associated immune manifestations and the burden of long-term complications and treatment toxicity. Future challenges include (1) the identification of the underlying genetic defects inducing immune dysregulation and (2) the need to better characterize patient subgroups and second-line treatment strategies.

Altered chemotactic response to CXCL12 in patients carrying GATA2 mutations

GATA2 deficiency—formerly described as MonoMAC syndrome; dendritic cells, monocytes, B cells, and natural killer cell deficiency; familial myelodysplastic syndrome/acute myeloid leukemia; or Emberger syndrome—encompasses a range of hematologic and nonhematologic anomalies, mainly characterized by monocytopenia, B lymphopenia, natural killer cell cytopenia, neutropenia, immunodeficiency, and a high risk of developing acute myeloid leukemia. Herein, we present 7 patients with GATA2 deficiency recruited into the French Severe Chronic Neutropenia Registry, which enrolls patients with all kinds of congenital neutropenia. We performed extended immunophenotyping of their whole blood lymphocyte populations, together with the analysis of their chemotactic responses. Lymphopenia was recorded for B and CD4+ T cells in 6 patients. Although only 3 patients displayed natural killer cell cytopenia, the CD56bright natural killer subpopulation was nearly absent in all 7 patients. Natural killer cells from 6 patients showed decreased CXCL12/CXCR4‐dependent chemotaxis, whereas other lymphocytes, and most significantly B lymphocytes, displayed enhanced CXCL12‐induced chemotaxis compared with healthy volunteers. Surface expression of CXCR4 was significantly diminished in the patients’ natural killer cells, although the total expression of the receptor was found to be equivalent to that of natural killer cells from healthy individual controls. Together, these data reveal that GATA2 deficiency is associated with impaired membrane expression and chemotactic dysfunctions of CXCR4. These dysfunctions may contribute to the physiopathology of this deficiency by affecting the normal distribution of lymphocytes and thus potentially affecting the susceptibility of patients to associated infections.

NUP98 is rearranged in 3.8% of pediatric AML forming a clinical and molecular homogenous group with a poor prognosis

Pediatric acute myeloid leukemia (AML) is a rare disease whose prognosis is highly variable according to factors such as chromosomal abnormalities. Recurrent genomic rearrangements are detected in half of pediatric AML by karyotype. NUcleoPorin 98 (NUP98) gene is rearranged with 31 different fusion partner genes. These rearrangements are frequently undetected by conventional cytogenetics, as the NUP98 gene is located at the end of the chromosome 11 short arm (11p15). By screening a series of 574 pediatric AML, we detected a NUP98 rearrangement in 22 cases (3.8%), a frequency similar to CBFB-MYH11 fusion gene (4.0%). The most frequent NUP98 fusion gene partner is NSD1. These cases are homogeneous regarding their biological and clinical characteristics, and associated with bad prognosis only improved by bone marrow transplantation. We detailed the biological characteristics of these AML by exome sequencing which demonstrated few recurrent mutations (FLT3 ITD, WT1, CEBPA, NBPF14, BCR and ODF1). The analysis of the clonal structure in these cases suggests that the mutation order in the NUP98-rearranged pediatric AML begins with the NUP98 rearrangement leading to epigenetic dysregulations then followed by mutations of critical hematopoietic transcription factors and finally, activation of the FLT3 signaling pathway.

Oral complications and dental care in children with acute lymphoblastic leukaemia.

Acute leukaemia is the most common type of childhood cancer, the acute lymphoblastic type accounting for the majority of cases. Children affected by leukaemia receive various forms of treatments including chemotherapeutic agents and stem cell transplants. Leukaemia and its treatment can directly or indirectly affect oral health and further dental treatments. The oral complications include mucositis, opportunistic infections, gingival inflammation and bleeding, xerostomia and carious lesions. An additional consideration in children is the impact of the treatments on the developing dentition and on orofacial growth. The aim of this review is to describe the oral complications in children with acute lymphoblastic leukaemia and the methods of prevention and management before, during and after the cancer treatment.

Topotecan-vincristine-doxorubicin in stage 4 high risk neuroblastoma patients failing to achieve a complete metastatic response to rapid COJEC : a SIOPEN study

Purpose Metastatic response to induction therapy for high-risk neuroblastoma is a prognostic factor. In the International Society of Paediatric Oncology Europe Neuroblastoma (SIOPEN) HR-NBL-1 protocol, only patients with metastatic complete response (CR) or partial response (PR) with ≤ three abnormal skeletal areas on iodine 123-metaiodobenzylguanidine ([123I]mIBG) scintigraphy and no bone marrow disease proceed to high dose therapy (HDT). In this study, topotecan-vincristine-doxorubicin (TVD) was evaluated in patients failing to achieve these criteria, with the aim of improving the metastatic response rate. Materials and Methods Patients with metastatic high-risk neuroblastoma who had not achieved the SIOPEN criteria for HDT after induction received two courses of topotecan 1.5 mg/m2/day for 5 days, followed by a 48-hour infusion of vincristine, 2 mg/m2, and doxorubicin, 45 mg/m2. Results Sixty-three patients were eligible and evaluable. Following two courses of TVD, four (6.4%) patients had an overall CR, while 28 (44.4%) had a PR with a combined response rate of 50.8% (95% confidence interval [CI], 37.9 to 63.6). Of these, 23 patients achieved a metastatic CR or a PR with ≤ 3 mIBG skeletal areas and no bone marrow disease (36.5%; 95% CI, 24.7 to 49.6) and were eligible to receive HDT. Toxicity was mostly haematological, affecting 106 of the 126 courses (84.1%; 95% CI, 76.5 to 90.0), and dose reduction was necessary in six patients. Stomatitis was the second most common nonhematological toxicity, occurring in 20 patients (31.7%). Conclusion TVD was effective in improving the response rate of high-risk neuroblastoma patients after induction with COJEC enabling them to proceed to HDT. However, the long-term benefits of TVD needs to be determined in randomized clinical trials.

ARID5B, IKZF1 and Non-Genetic Factors in the Etiology of Childhood Acute Lymphoblastic Leukemia: The ESCALE Study

Genome-wide association studies (GWAS) have identified that frequent polymorphisms in ARID5B and IKZF1, two genes involved in lymphoid differentiation, increase the risk of childhood acute lymphoblastic leukemia (ALL). These findings markedly modified the current field of research on the etiology of ALL. In this new context, the present exploratory study investigated the possible interactions between these at-risk alleles and the non-genetic suspected ALL risk factors that were of sufficient prevalence in the French ESCALE study: maternal use of home insecticides during pregnancy, preconception paternal smoking, and some proxies for early immune modulation, i.e. breastfeeding, history of common infections before age one year, and birth order. The analyses were based on 434 ALL cases and 442 controls of European origin, drawn from the nationwide population-based case-control study ESCALE. Information on non-genetic factors was obtained by standardized telephone interview. Interactions between rs10740055 in ARID5B or rs4132601 in IKZF1 and each of the suspected non-genetic factors were tested, with the SNPs coded as counts of minor alleles (trend variable). Statistical interactions were observed between rs4132601 and maternal insecticide use (p = 0.012), breastfeeding p = 0.017) and repeated early common infections (p = 0.0070), with allelic odds ratios (OR) which were only increased among the children not exposed to insecticides (OR = 1.8, 95%CI: 1.3, 2.4), those who had been breastfed (OR = 1.8, 95%CI: 1.3, 2.5) and those who had had repeated early common infections (OR = 2.4, 95%CI: 1.5, 3.8). The allelic ORs were close to one among children exposed to insecticides, who had not been breastfed and who had had no or few common infections. Repeated early common infections interacted with rs10740055 (p = 0.018) in the case-only design. Further studies are needed to evaluate whether these observations of a modification of the effect of the at-risk alleles by non-genetic factors are chance findings or reflect true underlying mechanisms.

Revisiting Splenectomy in Childhood Immune Thrombocytopenic Purpura in the Era of New Therapies: The French Experience

Objective: While splenectomy is the gold standard treatment for refractory primary immune thrombocytopenia (ITP) in adult, its place remains debated in children. The French Rare Disease Plan provided us the opportunity to conduct a collaborative study of the efficiency and tolerance of this procedure in childhood ITP. Patients and methods: A retrospective study was conducted in France in order to identify children with ITP treated with splenectomy during a 9-year period. A total of 78 children were included. Data from the ongoing CEREVANCE national cohort of childhood auto-immune cytopenia in 30 units were reviewed and completed by a direct contact with the referent physicians. International terminology for response definition was used. Relapsefree survival was assessed by the Kaplan-Meier method. Results: The median ages at ITP diagnosis and splenectomy were 9.6 and 12.4 years respectively. The median duration of ITP before splenectomy was 24 months (1-162); 62 children had chronic ITP. The median number of treatment lines before splenectomy was 2 (1-7). Laparoscopy was used in 81% of cases. Four children underwent immediate surgical complications. With a median follow-up of 41 months, complete remission (CR) was maintained at the latest news in 84% of children. CR was obtained in 77% of cases with intra-splenic platelets destruction, and in no case with non-splenic destruction (p=0.11). Using a very strict definition for relapse, the 5-year relapse-free survival was 51% [IC95% 37-64]. No death or overwhelming sepsis was reported. Conclusions: In this national study with a long term follow up, the excellent benefit/risk ratio of splenectomy for refractory ITP confirms that in skilled and concerted teams, the procedure is still at the forefront of curative treatments. Isotopic evaluation is of value but other prognostic factors for CR are to be determined. Lifelong survey of potential infectious and thrombotic risk at adult age has to be coordinated by the referring physician. The place for other therapeutic options, in order to postpone as late as possible the splenectomy in childhood ITP is now to be determined.

Physical health conditions and quality of life in adults with primary immunodeficiency diagnosed during childhood: A French Reference Center for PIDs (CEREDIH) study

Background: Most children with primary immunodeficiencies (PIDs) now reach adulthood. However, few studies have evaluated their health status and health‐related quality of life (HRQoL). Objective: To investigate long‐term morbidity, the French Reference Center for PIDs initiated a prospective multicenter cohort: the French Childhood Immune Deficiency Long‐term Cohort. The data collected were used to assess the physical health condition of patients who reached adulthood and the effect on their quality of life. Methods: Patients were asked to complete health status questionnaires. A severity score (grade 1 [mild] to grade 4 [life‐threatening]) was assigned to each health condition. The HRQoL of patients was compared with age‐ and sex‐matched French normal values by using the 36‐item Short‐Form Survey (SF‐36) HRQoL questionnaire. Results: Among 329 participants, the mean age at evaluation was 27.6 years, with a 21‐year mean follow‐up after diagnosis; 43% reported at least 1 grade 4 health condition, and 86% reported at least 1 grade 3 (severe) or 4 health condition. Twenty‐five (7.6%) patients had been treated for cancer. Compared with the French normal values, adults with PIDs scored significantly lower for all HRQoL domains. HRQoL was strongly associated with the burden of health conditions. The association with grade 4 or grade 3‐4 health conditions was highly significant for all physical and mental domains. Conclusion: Adults with PIDs diagnosed during childhood experienced a heavy burden of health conditions, which affected their HRQoL. Our results emphasize the need to closely monitor this vulnerable population.