[Suspicion of constitutional abnormality at diagnosis of childhood leukemia: Update of the leukemia committee of the French Society of Childhood Cancers]. / Suspicion d'anomalie constitutionnelle au diagnostic de leucémie chez l'enfant : mise au point du comité leucémies de la Société française des cancers de l'enfant.

The spectrum of childhood leukemia predisposition syndromes has grown significantly over last decades. These predisposition syndromes mainly involve CEBPA, ETV6, GATA2, IKZF1, PAX5, RUNX1, SAMD9/SAMD9L, TP53, RAS-MAPK pathway, DNA mismatch repair system genes, genes associated with Fanconi anemia, and trisomy 21. The clinico-biological features leading to the suspicion of a leukemia predisposition are highly heterogeneous and require varied exploration strategies. The study of the initial characteristics of childhood leukemias includes high-throughput sequencing techniques, which have increased the frequency of situations where a leukemia predisposing syndrome is suspected. Identification of a leukemia predisposition syndrome can have a major impact on the choice of chemotherapy, the indication for hematopoietic stem cell transplantation, and screening for associated malformations and pathologies. The diagnosis of a predisposition syndrome can also lead to the exploration of family members and genetic counseling. Diagnosis and management should be based on dedicated and multidisciplinary care networks.

Prediction of success of CD34+ collection for autotransplantation in children.

INTRODUCTION: Intensive chemotherapy with autologous stem cell transplantation is a therapeutic tool used in paediatric oncology. In adult patients, a peripheral blood CD34+ cell count superior to 20/µL enables an adequate collection of peripheral blood stem cells. There are no recommendations for children. This study aimed to determine whether the count of circulating CD34+ cells on the day before cytapheresis predicts successful collection in paediatric patients. METHODS: We retrospectively studied all paediatric patients who underwent apheresis for stem cell autotransplantation in the CHU of Rennes between 2010 and 2019. Successful apheresis was defined as a collection superior to 3×106 CD34+/kg. "Success" and "failure" groups were compared. RESULTS: In total, 122 apheresis procedures were performed in 105 patients. It was a successful procedure in 81% of patients and a failure in 19% of patients. A minimal cut-off of circulating CD34+ count superior to 13/µL on D-1 allowed us to predict a collection of at least 3×106 CD34+/kg (PPV 94,8%, NPV 51,4%). For children aged<6 years, the association with leucocyte increase during the 5 days before the procedure improved the prediction of success. DISCUSSION: The peripheral blood CD34+ cell count is a predictive factor for successful collection in paediatric patients. The minimal cut-off that allows an adequate collection of peripheral blood stem cells is inferior to the minimal cut-off in adult patients. Nevertheless, this minimal number of circulating CD34+ cells is insufficient to predict the success or failure of apheresis in patients younger than 6 years of age.

Hypoxia regulates CD9 expression and dissemination of B lymphoblasts.

Acute lymphoblastic leukemias (ALL) are the most frequent cancer in children and derive most often from B-cell precursors. Current survival rates roughly reach 90% at 10 years from diagnosis. However, 15-20% of children still relapse with a significant risk of death. Our previous work showed that the transmembrane protein CD9 plays a major role in lymphoblasts migration into sanctuary sites, especially in testis, through the activation of RAC1 signaling upon blasts stimulation with C-X-C chemokine ligand 12 (CXCL12). Here, we identified common factors shared by the bone marrow and extramedullary niches which could upregulate CD9 expression and function. We found that low oxygen levels enhance CD9 expression both at mRNA and protein levels. We further determined that Hypoxia Inducible Factor 1α (HIF1α), the master transcription factor involved in hypoxia response, binds directly CD9 promoter and induce CD9 transcription. We also showed that CD9 protein is crucial for leukemic cell adhesion and migration at low oxygen levels, possibly through its action on RAC1 signaling. Mouse xenograft experiments indicate that HIF1α signaling pathway promotes ALL cells engraftment in a CD9-dependent manner. The present work increments our understanding of CD9 implication in ALL pathogenesis.

Complication rates of proximal hypospadias: meta-analyses of four surgical repairs.

INTRODUCTION: Proximal hypospadias surgery is impacted by a high complication rate. The goal of this work was to assess the overall composite complication rate, fistula rate and stenosis rate following proximal hypospadias surgery realized according to onlay urethroplasty, Duckett, Koyanagi and Bracka techniques. METHODS: The databases MEDLINE, EMBASE, SCOPUS, Cochrane Library, the Cochrane Database of Systematic Reviews and the Cochrane Central Register of Controlled Trials (CENTRAL) and Sciencedirect were searched. Studies had to report data about the mean age of population, the average duration of patient follow-up and the number of procedures required for surgical treatment of primary and proximal hypospadias. Two independent including one urologist reviewers screened all the articles and selected the articles to be included. RESULTS: Overall composite complication rates were 32%, 34%, 49%, and 43%, for Onlay urethroplasty, Duckett's tubularized flaps urethroplasty, Koyanagi repair and Bracka 2 stages repair, respectively. Fistula rates were 13%, 18%, 21% and 23% respectively. The heterogeneity of complication rates reported in the different studies was not moderated by age, country, or patient's continent origin. DISCUSSION: The classifications of complications used in articles were disparate and make comparisons between techniques difficult. The report of post-surgical complications in the literature is often poorly coded and follow-up times were often too short. CONCLUSION: This meta-analysis attempts to determine to the extent possible, given the serious weaknesses in the hypospadias literature, plausible estimates of complication rates after skin flap urethroplasty. The patched onlay skin flap, the Duckett's tubularized skin flap technique, the Koyanagi's technique, and the Bracka's two-stage urethroplasty procedure lead to very high complication rates. Reported complication rates are comparable across techniques.

Severe cytomegalovirus disease with encephalitis after CAR-T cell therapy: A rare but potentially fatal complication.

Cytomegalovirus (CMV) is a ubiquitous herpes virus that develops lifelong latency following primary infection and can be reactivated following immune suppression. CMV encephalopathy has been described in few reports after hematopoietic stem cell transplantation and in patients with acquired immunodeficiency syndrome. To the best of our knowledge, CMV encephalopathy following CAR-T cells infusion had not been previously reported. Initial CMV viral load and monitoring are crucial in patients with CAR-T cells to allow early intervention with aggressive antiviral treatment without delay if needed.

Hepato-splenic candidiasis confirmed following splenectomy: a case report.

We report a case of severe refractory hepato-splenic candidiasis confirmed following splenectomy in an immunocompromised 54-year-old woman treated for acute lymphoblastic leukemia. Liver biopsies did not contribute to identifying the etiology of the multiple hepato-splenic lesions. In view of the lack of improvement after several lines of antifungal treatments, a splenectomy was performed and confirmed splenic candidiasis. PET/CT scan was used to monitor the evolution of hepato-splenic hypermetabolism. Splenectomy can be envisaged to establish fungal infection in immuno-compromised patients, to exclude relapse, and to guide the choice of antifungal agents.

Professional practice assessment: establishment of an institutional procedure to treat blunt abdominal trauma in emergency pediatric department.

OBJECTIVE: The clinical process for the diagnosis of intra-abdominal lesion due to blunt abdominal trauma in children is not consistent. The goal of the present study was to assess the efficiency of our institutional procedure to manage hemodynamically stable pediatric patients with benign abdominal trauma and to select patients who need a radiological examination in an emergency pediatric department. MATERIAL AND METHODS: This was a prospective cohort study from June 2008 to June 2010 in a pediatric emergency department. Pediatric patients with benign abdominal trauma and with stable hemodynamic parameters were included in the study. We conducted first clinical examination and clinical laboratory assessment for blood count, platelet count, hematocrit, serum glutamo-oxalacétique transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), lipase and urine. A second clinical examination was performed 2 h later. Patients with biological abnormalities and/or with persistent pain underwent a computerized tomography (CT) of the abdomen. Our main criterion for judging was the presence of intra-abdominal lesion as revealed by the scan, which was considered as the gold standard. At the second clinical examination, patients without pain and with normal results for clinical laboratory assessment were sent home. A telephone call was made to the children 48 h after the visit to the hospital emergency department. The secondary criterion for judging was the absence of complication in children who did not undergo the scan. RESULTS: A total of 111 children were included. Seventy-five children underwent the complete procedure. Thirty-four scans were performed. The scan revealed that 22 patients had an intra-abdominal lesion. Multivariate analysis indicated that SGOT higher than 34 IU/L and the persistence of pain for more than 2 h from the initial evaluation of trauma favored the development of intra-abdominal lesion. On the basis of these two criteria, we developed a predictive diagnostic score for post-traumatic intra-abdominal injuries with a high negative predictive value. For children who were sent home without a radiological examination, no complications were observed at 48 h after the visit to the emergency department. CONCLUSION: The present protocol is a good approach to identify children at risk for intra-abdominal lesion who need a radiological examination and those who do not require any complementary examinations. The predictive diagnostic score could help young hospital doctors to assess blunt abdominal trauma.

Assessment of chimerism and immunomodulation to prevent post-transplantation relapse in childhood acute myeloblastic leukemia: is it the right approach?

Relapse of acute myeloblastic leukemia (AML) after first allogenic hematopoietic stem-cell transplantation (allo-HSCT) is a fatal complication. Sixty-five children transplanted for AML were included in a prospective national study from June 2005 to July 2008 to explore the feasibility of preemptive immune modulation based on the monitoring of blood chimerism. Relapse occurred in 23 patients (35%). The median time between the last complete chimerism and relapse was 13.5 days (2-138). Prompt discontinuation of cyclosporin and the administration of donor lymphocyte infusions (DLIs) based on chimerism monitoring failed as a preemptive tool, either for detecting relapse or certifying long-term remission.

Mechanisms of extramedullary relapse in acute lymphoblastic leukemia: Reconciling biological concepts and clinical issues.

Long-term survival rates in childhood acute lymphoblastic leukemia (ALL) are currently above 85% due to huge improvements in treatment. However, 15-20% of children still experience relapses. Relapses can either occur in the bone marrow or at extramedullary sites, such as gonads or the central nervous system (CNS), formerly referred to as ALL-blast sanctuaries. The reason why ALL cells migrate to and stay in these sites is still unclear. In this review, we have attempted to assemble the evidence concerning the microenvironmental factors that could explain why ALL cells reside in such sites. We present criteria that make extramedullary leukemia niches and solid tumor metastatic niches comparable. Indeed, considering extramedullary leukemias as metastases could be a useful approach for proposing more effective treatments. In this context, we conclude with several examples of potential niche-based therapies which could be successfully added to current treatments of ALL.

Autoimmune Pancreatitis and Ulcerative Rectocolitis in an Adolescent.

Autoimmune pancreatitis (AIP) is rare in teenagers and difficult to diagnose. There are no clear and established diagnostic criteria in the pediatric population to distinguish subtype 1 and subtype 2. Here, we report the case of a 16-year-old white French teenager admitted to the pediatric emergency service with more than 1 year's history of pain originating from the epigastric and the right hypochondriac regions, with bloody diarrhea. After exclusion of pancreatic cancer and other common causes of acute pancreatitis, the diagnosis of AIP was suspected. Biological analyses revealed acute pancreatitis with severe cholestasis and an elevated level of serum immunoglobulin G4. Magnetic resonance cholangiography revealed a voluminous pancreas presenting a typical "sausage-like" aspect. Anatomopathological analyses of the liver biopsy specimen revealed a biliary obstruction due to pancreatic involvement without the typical aspect of chronic destructive cholangitis. Corticotherapy and immunosuppressive treatment proved effective after 1 week of treatment. Without a pancreatic biopsy specimen, the distinction between AIP type 1 and 2 could not be made clearly in this case. The succession of clinical observations could allow clinicians to recognize, treat, and manage AIP in children.

Renal failure in pediatric Castleman disease: Four French cases with thrombotic microangiopathy.

Pediatric Castleman disease (CD) is an uncommon and poorly understood disorder of the lymph nodes. Renal failure has not been described in pediatric multicentric CD (MCD). We report four cases, who presented with polyadenopathy, organomegaly, edema and fluid accumulations, high blood pressure, and acute renal failure. In all cases, renal biopsy confirmed diffuse thrombotic microangiopathy. Definitive diagnosis of MCD was made by a biopsy of an affected lymph node located by computer tomography before initiation of corticosteroid therapy. Treatment of CD with corticosteroid therapy and rituximab was rapidly effective without relapse to date.