ITGB2 mutation combined with deleted ring 21 chromosome in a child with leukocyte adhesion deficiency

Leukocyte adhesion deficiency type 1(LAD-1) is a rare autosomal recessive primary immunodeficiency caused by defects in the ITGB2 gene located on chromosome 21q22. Clinically, LAD-1 patients are characterized by recurrent infections, slow wound healing and dystrophic scars after skin injuries, associated with persistent neutrophilia. The severity of symptoms is related to the level of CD11/CD18 expression on patients’ leucocytes and those with less than 1% expression treated with hematopoietic stem cell transplant (HSCT). We present a child affected by LAD-1 who received HSCT from a matched unrelated donor. Molecular analysis revealed apparent homozygosis for a point mutation in the ITGB2 gene, only the mother however was carrier of the mutation. Cytogenetic and FISH analysis showed the presence of a de-novo ring chromosome 21. Whole Genome Analysis with the Affymetrix GeneChip Human Mapping 250K NspI array confirmed in the child the presence of a de novo deletion of the chromosomal region 21q22.3-qter, where the ITGB2 gene maps. While HSCT resulted in successful engraftment and correction of the immunodeficiency, all the phenotypic features of ring (21) syndrome with a deletion of a 4.6Mb (including 69 genes) clearly remained unchange

Missense mutations in the Fas gene resulting in autoimmune lymphoproliferative syndrome: a molecular and immunological analysis

Programmed cell death (or apoptosis) is a physiological process essential to the normal development and homeostatic maintenance of the immune system. The Fas/Apo-1 receptor plays a crucial role in the regulation of apoptosis, as demonstrated by lymphoproliferation in MRL-lpr/lpr mice and by the recently described autoimmune lymphoproliferative syndrome (ALPS) in humans, both of which are due to mutations in the Fas gene. We describe a novel family with ALPS in which three affected siblings carry two distinct missense mutations on both the Fas gene alleles and show lack of Fas-induced apoptosis. The children share common clinical features including splenomegaly and lymphadenopathy, but only one developed severe autoimmune manifestations. In all three siblings, we demonstrated the presence of anergic CD3+CD4-CD8- (double negative, [DN]) T cells; moreover, a chronic lymphocyte activation was found, as demonstrated by the presence of high levels of HLA-DR expression on peripheral CD3+ cells and by the presence of high levels of serum activation markers such as soluble interleukin-2 receptor (slL-2R) and soluble CD30 (sCD30)

Lentiviral gene therapy corrects platelet phenotype and function in patients with Wiskott-Aldrich syndrome

BACKGROUND: Thrombocytopenia is a serious issue for all patients with classical Wiskott-Aldrich syndrome (WAS) and X-linked thrombocytopenia (XLT) because it causes severe and life-threatening bleeding. Lentiviral gene therapy (GT) for WAS has shown promising results in terms of immune reconstitution. However, despite the reduced severity and frequency of bleeding events, platelet counts remain low in GT-treated patients. OBJECTIVE: We carefully investigated platelet defects in terms of phenotype and function in untreated patients with WAS and assessed the effect of GT treatment on platelet dysfunction. METHODS: We analyzed a cohort of 20 patients with WAS/XLT, 15 of them receiving GT. Platelet phenotype and function were analyzed by using electron microscopy, flow cytometry, and an aggregation assay. Platelet protein composition was assessed before and after GT by means of proteomic profile analysis. RESULTS: We show that platelets from untreated patients with WAS have reduced size, abnormal ultrastructure, and a hyperactivated phenotype at steady state, whereas activation and aggregation responses to agonists are decreased. GT restores platelet size and function early after treatment and reduces the hyperactivated phenotype proportionally to WAS protein expression and length of follow-up. CONCLUSIONS: Our study highlights the coexistence of morphologic and multiple functional defects in platelets lacking WAS protein and demonstrates that GT normalizes the platelet proteomic profile with consequent restoration of platelet ultrastructure and phenotype, which might explain the observed reduction of bleeding episodes after GT. These results are instrumental also from the perspective of a future clinical trial in patients with XLT only presenting with microthrombocytopenia

EXTL3 mutations cause skeletal dysplasia, immune deficiency, and developmental delay.

We studied three patients with severe skeletal dysplasia, T cell immunodeficiency, and developmental delay. Whole-exome sequencing revealed homozygous missense mutations affecting exostosin-like 3 (EXTL3), a glycosyltransferase involved in heparan sulfate (HS) biosynthesis. Patient-derived fibroblasts showed abnormal HS composition and altered fibroblast growth factor 2 signaling, which was rescued by overexpression of wild-type EXTL3 cDNA. Interleukin-2-mediated STAT5 phosphorylation in patients' lymphocytes was markedly reduced. Interbreeding of the extl3-mutant zebrafish (box) with Tg(rag2:green fluorescent protein) transgenic zebrafish revealed defective thymopoiesis, which was rescued by injection of wild-type human EXTL3 RNA. Targeted differentiation of patient-derived induced pluripotent stem cells showed a reduced expansion of lymphohematopoietic progenitor cells and defects of thymic epithelial progenitor cell differentiation. These data identify EXTL3 mutations as a novel cause of severe immune deficiency with skeletal dysplasia and developmental delay and underline a crucial role of HS in thymopoiesis and skeletal and brain development

Reduced thymic output, cell cycle abnormalities, and increased apoptosis of T lymphocytes in patients with cartilage-hair hypoplasia

Producción CientíficaBackground: Cartilage-hair hypoplasia (CHH) is characterized by metaphyseal dysplasia, bone marrow failure, increased risk of malignancies, and a variable degree of immunodeficiency. CHH is caused by mutations in the RNA component of the mitochondrial RNA processing (RMRP) endoribonuclease gene, which is involved in ribosomal assembly, telomere function, and cell cycle control. Objectives: We aimed to define thymic output and characterize immune function in a cohort of patients with molecularly defined CHH with and without associated clinical immunodeficiency. Methods: We studied the distribution of B and T lymphocytes (including recent thymic emigrants), in vitro lymphocyte proliferation, cell cycle, and apoptosis in 18 patients with CHH compared with controls. Results: Patients with CHH have a markedly reduced number of recent thymic emigrants, and their peripheral T cells show defects in cell cycle control and display increased apoptosis, resulting in poor proliferation on activation. Conclusion: These data confirm that RMRP mutations result in significant defects of cell-mediated immunity and provide a link between the cellular phenotype and the immunodeficiency in CH

The European internet-based patient and research database for primary immunodeficiencies: results 2006-2008

Primary immunodeficiencies (PID) are rare diseases; therefore transnational studies are essential to maximize the scientific outcome and to improve diagnosis and therapy. In order to estimate the prevalence of PID in Europe as well as to establish and evaluate harmonized guidelines for the diagnosis and treatment of PID, the European Society for Immunodeficiencies (ESID) has developed an internet-based database for clinical and research data on patients with PID. This database is a platform for epidemiological analyses as well as the development of new diagnostic and therapeutic strategies and the identification of novel disease-associated genes. Within 4 years, 7430 patients from 39 countries have been documented in the ESID database. Common variable immunodeficiency (CVID) represents the most common entity, with 1540 patients or 20.7% of all entries, followed by isolated immunoglobulin (Ig)G subclass deficiency (546 patients, 7.4%). Evaluations show that the average life expectancy for PID patients varies from 1 to 49 years (median), depending on the type of PID. The prevalence and incidence of PID remains a key question to be answered. As the registration progress is far from finished we can only calculate minimum values for PID, with e.g. France currently showing a minimum prevalence of 3.72 patients per 100,000 inhabitants. The most frequently documented permanent treatment is immunoglobulin replacement; 2819 patients (42% of all patients alive) currently receive this form of treatment

Pro‑differentiating compounds for human intervertebral disc cells are present in Violina pumpkin leaf extracts

The intervertebral disc degeneration (IDD) is closely associated with inflammation, oxidative stress and loss of the discogenic phenotype which current therapies are unable to reverse. Here, the effects of acetone extract from Violina pumpkin (Cucurbita moschata) leaves on degenerated intervertebral disc (IVD) cells was investigated. IVD cells were isolated from degenerated disc tissue of patients undergoing spinal surgery, and exposed to acetone extract and three major thin layer chromatography subfractions. We found that the cells benefit from exposure in particular to subfraction 7 consisting almost entirely of p-Coumaric acid. Subfraction 7-treated cells showed a significant increase of discogenic transcription factors (SOX9, TRPS1), extracellular matrix components (aggrecan, collagen type II), cellular homeostasis and stress response regulators (FOXO3a, Nrf2, SOD2, SIRT1). Migratory ability and the expression of OCT4, two important markers related to the presence and activity of stem cells also increased. Moreover, subfraction 7 counteractes H2O2-triggered cell damage preventing in particular the increase of the pro-inflammatory and antichondrogenic microRNA, miR-221. This strengthens the hypothesis that adequate stimuli can support resident cells to repopulate the degenerate IVD and restart the anabolic machinery. Taken together, the data we obtained contribute to the discovery of molecules potentially effective in slowing the progression of IDD, a disease for which there is currently no effective treatment. Moreover, the enhancement of a part of plant, the pumpkin leaves, considered a waste product in the Western world, demonstrating that it contains substances with potential beneficial effects on human health

Inactivating Mutations in NPC1L1 and Protection from Coronary Heart Disease

Background Ezetimibe lowers plasma levels of low-density lipoprotein (LDL) cholesterol by inhibiting the activity of the Niemann–Pick C1-like 1 (NPC1L1) protein. However, whether such inhibition reduces the risk of coronary heart disease is not known. Human mutations that inactivate a gene encoding a drug target can mimic the action of an inhibitory drug and thus can be used to infer potential effects of that drug. Methods We sequenced the exons of NPC1L1 in 7364 patients with coronary heart disease and in 14,728 controls without such disease who were of European, African, or South Asian ancestry. We identified carriers of inactivating mutations (nonsense, splice-site, or frameshift mutations). In addition, we genotyped a specific inactivating mutation (p.Arg406X) in 22,590 patients with coronary heart disease and in 68,412 controls. We tested the association between the presence of an inactivating mutation and both plasma lipid levels and the risk of coronary heart disease. Results With sequencing, we identified 15 distinct NPC1L1 inactivating mutations; approximately 1 in every 650 persons was a heterozygous carrier for 1 of these mutations. Heterozygous carriers of NPC1L1 inactivating mutations had a mean LDL cholesterol level that was 12 mg per deciliter (0.31 mmol per liter) lower than that in noncarriers (P = 0.04). Carrier status was associated with a relative reduction of 53% in the risk of coronary heart disease (odds ratio for carriers, 0.47; 95% confidence interval, 0.25 to 0.87; P = 0.008). In total, only 11 of 29,954 patients with coronary heart disease had an inactivating mutation (carrier frequency, 0.04%) in contrast to 71 of 83,140 controls (carrier frequency, 0.09%). Conclusions Naturally occurring mutations that disrupt NPC1L1 function were found to be associated with reduced plasma LDL cholesterol levels and a reduced risk of coronary heart disease.National Human Genome Research Institute (U.S.) (Grant 5U54HG003067-11