Prevalence and risk factors of iron overload after hematopoietic stem cell transplantation for childhood acute leukemia: a LEA study.

Data on post-transplant iron overload (IO) are scarce in pediatrics. We conducted a prospective multicenter cohort study (Leucémie de l'Enfant et de l'Adolescent cohort) to determine the prevalence and risk factors of IO in 384 acute leukemia survivors transplanted during childhood. Prevalence of IO (ferritin level ⩾350 ng/mL) was 42.2% (95%CI 37.2-47.2%). Factors significantly associated with IO were: 1) in univariate analysis: older age at transplant (P<0.001), allogeneic versus autologous transplantation (P<0.001), radiation-based preparative regimen (P=0.035) and recent period of transplantation (P<0.001); 2) in multivariate analysis: older age at transplant in quartiles (Odds Ratio (OR)=7.64, 95% CI: 3.73-15.64 for age >12.7 years and OR=5.36, 95% CI: 2.63-10.95 for age from 8.2 to 12.7 years compared to age < 4.7 years), acute myeloid leukemia (OR=3.23, 95% CI: 1.47-7.13), allogeneic graft (OR=4.34, 95% CI: 2.07-9.12 for alternative donors and OR=2.53, 95% CI: 1.2-5.33 for siblings, compared to autologous graft) and radiation-based conditioning regimen (OR=2.45, 95% CI: 1.09-5.53). Graft-versus-host disease was an additional risk factor for allogeneic graft recipients. In conclusion, IO is a frequent complication in pediatric long-term survivors after transplantation for acute leukemia, more frequently observed in older children, those transplanted from alternative donors or with graft-versus-host disease.

Metabolic syndrome in adults who received hematopoietic stem cell transplantation for acute childhood leukemia: an LEA study.

We evaluated prospectively the incidence and risk factors of the metabolic syndrome (MS) and its components in 170 adult patients (mean age at evaluation: 24.8±5.4 years) who received an hematopoietic stem cell transplantation for childhood ALL, n=119, or AML, n=51. TBI was carried out in 124 cases; a busulfan-based conditioning was done in 30 patients. Twenty-nine patients developed a MS (17.1%, 95% confidence intervals: 11.7-23.6). The cumulative incidence was 13.4% at 25 years of age and 35.5% at 35 years of age. A higher body mass index (BMI) before transplantation and a growth hormone deficiency were associated with increased MS risk (P=0.002 and 0.01, respectively). MS risk was similar for patients who received TBI or busulfan-based conditioning. The TBI use increased the hyperglycemia risk (odds ratio (OR): 4.7, P=0.02). Women were at the risk of developing increased waist circumference (OR: 7.18, P=0.003) and low levels of high-density lipoprotein cholesterol (OR: 2.72, P=0.007). The steroid dose was not a risk factor. The MS occurs frequently among transplanted survivors of childhood leukemia. Its incidence increases with age. Both intrinsic (BMI, gender) and extrinsic factors (TBI, alkylating agents) contribute to its etiopathogenesis.

[Adenosine deaminase 1 deficiency, an inborn error of metabolism underlying a severe form of combined immunodeficiency]. / Déficit complet en adénosine-désaminase-1 : une erreur innée du métabolisme responsable d'un déficit immunitaire combiné sévère.

Severe combined immune deficiencies (SCIDs) are a heterogeneous group of severe cellular immunodeficiencies. Early diagnosis is essential to allow adapted care before life-threatening systemic infections or complications associated with live vaccines. Adenosine deaminase 1 deficiency (ADA1) is an inborn error of metabolism leading to severe lymphopenia and characteristic bone lesions. Herein, we present the typical case of a child in whom ADA SCID was diagnosed at 2 months of life, revealed by lung involvement and extreme lymphopenia. Immune restoration in terms of peripheral lymphocyte count with enzyme replacement therapy, namely pegylated bovine ADA, is satisfactory so far. The search for a compatible donor is underway. Correcting the genetic defect by gene transfer is also being considered. The phenotype of this very rare condition is described. A severe peripheral lymphopenia in a young child is a finding of utmost importance for the diagnosis of a primary cellular immunodeficiency.

[Paraneoplastic limbic encephalitis: 2 pediatric cases]. / Encéphalites limbiques paranéoplasiques de l'enfant : à propos de 2 observations.

The term "paraneoplastic neurologic disorders" refers to a group of syndromes mediated by immune responses triggered by tumors that express neuronal proteins or by immunological disturbances caused by the tumor. In most cases, limbic encephalitis is a disorder of adulthood, particularly in association with small-cell lung cancer or a testicular germ-cell tumor. The clinical picture of this disorder includes anxiety, depression, confusion, delirium, hallucinations, short-term memory loss and sometimes seizures. We report on 2 new pediatric cases from a single hospital: in the first case, limbic encephalitis revealed Hodgkin lymphoma; it heralded meningeal relapse of acute lymphoblastic leukemia in the other. Despite its extreme rarity, this syndrome is a possible diagnosis in childhood.

[Factor XIII deficiency in a newborn]. / Déficit en facteur XIII chez un nouveau-né.

Factor XIII deficiency is an uncommon inherited disorder which is characterized by umbilical cord bleeding and an unusually high incidence of intracranial hemorrhage. We report here a case of Factor XIII deficiency in a child that presented a caput. succedaneum as the first manifestation of the disease and then an umbilical cord bleeding. The importance of performing a quantitative FXIII assay in the presence of strong clinical suspicion is strengthened because of the normality of the standard screening tests and the important therapeutic consequences.