Clinical and immunologic phenotype associated with activated phosphoinositide 3-kinase δ syndrome 2: A cohort study.

BACKGROUND: Activated phosphoinositide 3-kinase δ syndrome (APDS) 2 (p110δ-activating mutations causing senescent T cells, lymphadenopathy, and immunodeficiency [PASLI]-R1), a recently described primary immunodeficiency, results from autosomal dominant mutations in PIK3R1, the gene encoding the regulatory subunit (p85α, p55α, and p50α) of class IA phosphoinositide 3-kinases. OBJECTIVES: We sought to review the clinical, immunologic, and histopathologic phenotypes of APDS2 in a genetically defined international patient cohort. METHODS: The medical and biological records of 36 patients with genetically diagnosed APDS2 were collected and reviewed. RESULTS: Mutations within splice acceptor and donor sites of exon 11 of the PIK3R1 gene lead to APDS2. Recurrent upper respiratory tract infections (100%), pneumonitis (71%), and chronic lymphoproliferation (89%, including adenopathy [75%], splenomegaly [43%], and upper respiratory tract lymphoid hyperplasia [48%]) were the most common features. Growth retardation was frequently noticed (45%). Other complications were mild neurodevelopmental delay (31%); malignant diseases (28%), most of them being B-cell lymphomas; autoimmunity (17%); bronchiectasis (18%); and chronic diarrhea (24%). Decreased serum IgA and IgG levels (87%), increased IgM levels (58%), B-cell lymphopenia (88%) associated with an increased frequency of transitional B cells (93%), and decreased numbers of naive CD4 and naive CD8 cells but increased numbers of CD8 effector/memory T cells were predominant immunologic features. The majority of patients (89%) received immunoglobulin replacement; 3 patients were treated with rituximab, and 6 were treated with rapamycin initiated after diagnosis of APDS2. Five patients died from APDS2-related complications. CONCLUSION: APDS2 is a combined immunodeficiency with a variable clinical phenotype. Complications are frequent, such as severe bacterial and viral infections, lymphoproliferation, and lymphoma similar to APDS1/PASLI-CD. Immunoglobulin replacement therapy, rapamycin, and, likely in the near future, selective phosphoinositide 3-kinase δ inhibitors are possible treatment options.

Final height and body mass index after fractionated total body irradiation and allogeneic stem cell transplantation in childhood leukemia.

Impaired linear growth has been reported in patients treated during childhood with allogeneic stem cell transplantation and fractionated total body irradiation (fTBI). The objective of this study was to determine the final height and body mass index (BMI) achieved. Forty-nine patients with leukemia were included and surveyed for more than 5 years. Median age at follow-up was 24.3 years (range, 18.9-35.8) and median follow-up time from allograft was 14.4 years (range, 4.5-21.9). Mean height standard deviation score (s.d.s.) at final examination (-1.1 ± 1.3,) was significantly lower than at fTBI (0.3 ± 1.2; P = .001). Final height s.d.s. was significantly correlated with age at diagnosis, age at fTBI, and target height (P = .001; P < .001; P < .001, respectively). Final height was significantly lower in children transplanted before age 5 (P = .006). Growth hormone treatment (n = 6) had only a modest effect on growth velocity. Mean BMI at follow-up was normal at 19.6 kg/m(2) for boys and 21.2 for girls, but with a significant decrease since allograft only for boys (-1.2 ± 1.5 s.d.s.) (P = .003). In conclusion, final height is decreased; BMI is normal but decreased from fTBI in boys.

Hyper-IgM syndrome type 4 with a B lymphocyte-intrinsic selective deficiency in Ig class-switch recombination.

Hyper-IgM syndrome (HIGM) is a heterogeneous condition characterized by impaired Ig class-switch recombination (CSR). The molecular defects that have so far been associated with this syndrome - which affect the CD40 ligand in HIGM type 1 (HIGM1), CD40 in HIGM3, and activation-induced cytidine deaminase (AID) in HIGM2 - do not account for all cases. We investigated the clinical and immunological characteristics of 15 patients with an unidentified form of HIGM. Although the clinical manifestations were similar to those observed in HIGM2, these patients exhibited a slightly milder HIGM syndrome with residual IgG production. We found that B cell CSR was intrinsically impaired. However, the generation of somatic hypermutations was observed in the variable region of the Ig heavy chain gene, as in control B lymphocytes. In vitro studies showed that the molecular defect responsible for this new HIGM entity (HIGM4) occurs downstream of the AID activity, as the AID gene was induced normally and AID-induced DNA double-strand breaks in the switch micro region of the Ig heavy chain locus were detected during CSR as normal. Thus, HIGM4 is probably the consequence of a selective defect either in a CSR-specific factor of the DNA repair machinery or in survival signals delivered to switched B cells.

Mutation spectrum of human SLC39A4 in a panel of patients with acrodermatitis enteropathica.

Acrodermatitis enteropathica is rare autosomal recessive disorder characterized by a severe nutritional zinc deficiency. We and others have recently identified the human gene encoding an intestinal zinc transporter of the ZIP family, SLC39A4, as the mutated gene in acrodermatitis enteropathica (AE). A first mutation screening in 8 AE families (15 patients out of 36 individuals) revealed the presence of six different mutations described elsewhere. Based on these results, we have evaluated the involvement of SLC39A4 in 14 patients of 12 additional AE pedigees coming either from France, Tunisia, Austria or Lithuania. A total of 7 SLC39A4 mutations were identified (1 deletion, 2 nonsense, 2 missense, and 2 modifications of splice site), of which 4 are novel: a homozygous nonsense mutation in 3 consanguineous Tunisian families [c.143T>G (p.Leu48X)], a heterozygous nonsense mutation (c.1203G>A (p.Trp401X)) in a compound heterozygote from Austria also exhibiting an already known missense mutation, and distinct homozygous mutations in families from France or Tunisia [c.475-2A>G and c.184T>C (p.Cys62Arg)]. Furthermore, two other potential mutations [c.850G>A (p.Glu284Lys) and c.193-113T>C] were also observed at homozygous state in a French family formerly described. This study brings to 21 the number of reported SLC39A4 mutations in AE families.

[The "do-not-resuscitate order" in paediatric palliative home care: why should the emergency team be involved ?]. / L'anticipation de la non-réanimation en soins palliatifs pédiatrique à domicile : le Samu comme partenaire de soins ?

Major challenge in paediatric palliative home care is to anticipate management of future events. In our opinion, one of major approach is to avoid medical futility especially resuscitation attempts in terminally-ill children especially if home care will be organized. We therefore prospectively discussed with proxi what should be attempted (e.g. treat symptoms of pain or discomfort) and what should be avoided for the sake of the child. A crucial part of the discussion included anticipating non resuscitation of the terminally-ill child. We informed in writing local emergency unit coordinator on results of the discussion with care takers and suggested a procedure in case of an emergency call. To include the local emergency unit is now a standard in our paediatric oncology department since two situations may occur: 1) Parental panic while facing difficult terminal symptoms. We recommend that the local emergency unit coordinator dispatches an emergency team to the child's home in order to manage symptoms (seizures, pain, etc.) but avoid any futile resuscitation attempt. Parental decision to maintain the child at home should be re-evaluated regularly. 2) Parents who wish to stay at home as long as possible, refusing home-based death of their terminally-ill child. We recommend that the family doctor decides whether or not to refer the child to the hospital. Emergency team may be called upon based on the child's status and need for medicalised transport. Even if it should be rather rare that parents contact directly the emergency unit and not as usually the home care coordinator, such situation may occur and should be anticipated. Therefore, the anticipation of non-resuscitation recommendations is a key approach in paediatric palliative home care. This complex discussion should not be avoided as parental/medical panic may induce unrealistic requests for futile medical procedures.