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Luigi D Notarangelo

Publications and source records attributed to Luigi D Notarangelo.

At least 19 recordsLinked to original sources
PubMed2025

The ClinGen Severe Combined Immunodeficiency Disease Variant Curation Expert Panel: Specifications for classification of variants in ADA, DCLRE1C, IL2RG, IL7R, JAK3, RAG1, and RAG2.

PURPOSE: This collaborative study, led by the Clinical Genome Resource Severe Combined Immunodeficiency Disease Variant Curation Expert Panel (ClinGen SCID-VCEP), implemented and adapted the American College of Medical Genetics and Genomics/Association for Molecular Pathology (ACMG/AMP) guidelines for interpreting germline variants in genes with established relationships to SCID. The effort focused on the 7 most common SCID-related genes identified by SCID newborn screening in North America: ADA, DCLRE1C, IL2RG, IL7R, JAK3, RAG1, and RAG2. METHODS: The SCID-VCEP conducted a rigorous review of variants that involved database analyses, literature review, and expert feedback to derive gene-specific modifications to the ACMG/AMP guidelines. These specifications were validated using a pilot set of 90 variants. RESULTS: Of these 90 variants, 25 were classified as pathogenic, 21 as likely pathogenic, 14 as variants of uncertain significance, 18 as likely benign, and 12 as benign. Seventeen variants with conflicting classifications in ClinVar were successfully resolved. The criteria included modifications to 20 of the 28 original ACMG/AMP criteria specific to SCID-related genes. CONCLUSION: The SCID-specific variant curation guidelines developed by the SCID-VCEP will enhance the precision of SCID genetic diagnosis and provide a robust framework for interpreting variants in SCID-related genes, contributing to appropriate treatment of SCID.

Humans↗
PubMed2006

The awareness among paediatricians of off-label prescribing in children: a survey of Italian hospitals.

OBJECTIVE: To investigate paediatricians' perception and awareness of off-label (OL) and unlicensed drug usage in clinical practice. METHODS: We conducted a questionnaire-based, observational study involving 28 departments/specialty units of four tertiary paediatrics Italian hospitals. The questionnaire was sent to a designated paediatrician in each department/specialty unit with the request that they summarise their awareness of OL prescriptions after a group discussion with all paediatricians working in the same department/unit. RESULTS: A total of 95 drugs were identified. The most common perceived reasons detected for OL use were age and formulation. Corticosteroids, ACE-inhibitors, beta-blockers and calcium-antagonists were most frequently indicated as OL for formulation, while ACE-inhibitors, new generation anti-epilepsy drugs, immunosuppressants, ketorolac and propofol as OL for age. Adrenaline, midazolam and ACE-inhibitors were indicated as unlicensed for route of administration. We found a high concordance between the OL drugs identified by physicians and those reported in the "Italian Summary Product Characteristics". CONCLUSIONS: Italian paediatricians perceived different drugs as unlicensed/OL from those identified by existing prescriptions studies. These perceived drugs may represent a priority in tackling the problem of OL usage in the hospital practice. The review of the Italian Summary Product Characteristics of some of the drugs identified, together with the monitoring of permanent clinical practice and with new clinical research, may be a step forward to reduce OL use in children.

Attitude of Health Personnel↗
PubMed2006

Defective Th1 cytokine gene transcription in CD4+ and CD8+ T cells from Wiskott-Aldrich syndrome patients.

Wiskott-Aldrich syndrome (WAS) protein (WASP) plays a key role in TCR-mediated activation and immunological synapse formation. However, the effects of WASP deficiency on effector functions of human CD4+ and CD8+ T cells remain to be determined. In this study, we report that TCR/CD28-driven proliferation and secretion of IL-2, IFN-gamma, and TNF-alpha are strongly reduced in CD8+ T cells from WAS patients, compared with healthy donor CD8+ T cells. Furthermore, WAS CD4+ T cells secrete low levels of IL-2 and fail to produce IFN-gamma and TNF-alpha, while the production of IL-4, IL-5, and IL-10 is only minimally affected. Defective IL-2 and IFN-gamma production persists after culture of naive WAS CD4+ T cells in Th1-polarizing conditions. The defect in Th1 cytokine production by WAS CD4+ and CD8+ T cells is also present at the transcriptional level, as shown by reduced IL-2 and IFN-gamma mRNA transcripts after TCR/CD28 triggering. The reduced transcription of Th1 cytokine genes in WAS CD4+ T cells is associated with a defective induction of T-bet mRNA and a reduction in the early nuclear recruitment of NFAT-1, while the defective activation of WAS CD8+ T cells correlates with reduced nuclear recruitment of both NFAT-1 and NFAT-2. Together, our data indicate that WASP regulates the transcriptional activation of T cells and is required specifically for Th1 cytokine production.

Adult↗
PubMed2006

Clinical, immunological and molecular characteristics of 37 Iranian patients with X-linked agammaglobulinemia.

BACKGROUND: X-linked agammaglobulinemia (XLA) is a hereditary immunodeficiency characterized by an early onset of recurrent bacterial infections, a profound deficiency of all immunoglobulin isotypes and a markedly reduced number of peripheral B lymphocytes. Eighty-five percent of the patients with this phenotype have mutations in Bruton's tyrosine kinase (BTK) gene. METHODS: To provide an informative outlook of clinical and immunological manifestations of XLA in Iran, 37 Iranian male patients with an age range of 1-34 years, followed over a period of 25 years, were studied. Twenty-four of the 37 patients were screened for BTK gene mutation using PCR-SSCP followed by direct sequencing. BTK protein expression assay was done by flow cytometry in 9 families. RESULTS: All patients first presented with infectious diseases, the most common of which were respiratory tract infections. Eighteen different mutations were identified, 13 of which were novel: IVS1+5G>C, 1896G>A, 349delA, 1618C>T, 1783T>C, 2084A>G, 1346delT, 1351delGAG, 587A>G, IVS14-1G>A, IVS3+2T>C, 1482G>A, 1975C>A. CONCLUSION: The fact that we found a great number of novel mutations in a relatively limited number of patients underlines the heterogeneity of BTK mutations in the Iranian population. The large number of new mutations indicates that extended studies in this region would be rewarding.

Adolescent↗
PubMed2006

Innate immunity defects in Hermansky-Pudlak type 2 syndrome.

Adaptor protein-3 (AP-3) is an ubiquitous cytoplasmic complex that shuttles cargo proteins from the trans-Golgi and a tubular-endosomal compartment to endosome-lysosome-related organelles. Lack of the beta3A subunit of this complex causes Hermansky-Pudlak syndrome type 2, an autosomal recessive disease characterized by partial albinism, prolonged bleeding tendency, and immunodeficiency. To investigate the pathogenesis of immunodeficiency, we studied natural killer (NK) cells and neutrophil functions in 2 previously unreported siblings affected by Hermansky-Pudlak type 2 syndrome. In both patients we observed a dramatic reduction of cytolytic activity of freshly isolated and of IL-2-activated NK cells. Levels of perforin were reduced in unstimulated NK cells, thereby accounting for the impairment of NK cytolitic activity. In addition, analysis of neutrophils in these patients demonstrated that intracellular elastase content was largely reduced while CD63 expression on plasma membrane was substantially increased. Taken together, these observations suggest that type 2 Hermansky-Pudlak syndrome is characterized by defects of innate immunity.

Adaptor Protein Complex 3↗
PubMed2006

Bone marrow transplantation for severe combined immune deficiency.

CONTEXT: Bone marrow transplantation (BMT) using stem cells obtained from a family-related, HLA-identical donor (RID) is the optimal treatment for patients with severe combined immune deficiency (SCID). In the absence of an RID, HLA-mismatched related donors (MMRDs) are often used. However, compared with RIDs, use of MMRDs for BMT is associated with reduced survival and inferior long-term immune reconstitution. Use of HLA-matched unrelated donors (MUDs) represents another potential alternative for BMT. OBJECTIVE: To compare outcomes and immune reconstitution in a large cohort of patients with SCID who received RID, MUD, or MMRD BMT. DESIGN, SETTING, AND PATIENTS: Retrospective study of medical records from 94 infants diagnosed as having SCID who received BMT between 1990 and 2004 at 1 Canadian and 1 Italian pediatric referral center. Thirteen, 41, and 40 patients received RID, MUD, and MMRD BMT, respectively. MAIN OUTCOME MEASURES: Survival and graft failure, along with incidence of graft-vs-host disease, infections, and other complications; immune reconstitution was assessed in children who survived for more than 2 years after BMT. RESULTS: Survival after RID BMT was highest. Twelve (92.3%) of 13 patients who received RID BMT, 33 (80.5%) of 41 who received MUD BMT, and 21 (52.5%) of 40 patients who received MMRD BMT survived. Compared with MMRD BMT, survival was significantly higher with RID (P = .008) or with MUD (P = .03). Graft failures and need for repeat BMT were more common in patients receiving MMRD BMT than in those who underwent MUD BMT. Long-term reconstitution of a full T-cell repertoire was achieved more frequently following MUD BMT (94.7%) than after MMRD BMT (61.1%) (P = .02). Acute graft-vs-host disease was documented in 73.1% of patients following MUD BMT but in only 45% after MMRD BMT (P = .009). Conversely, interstitial pneumonitis was observed more frequently after MMRD BMT (14 [35.0%] of 40) than after MUD BMT (3 [7.3%] of 41; P = .002). CONCLUSION: Our study suggests that in the absence of a relative with identical HLA, MUD BMT may provide better engraftment, immune reconstitution, and survival for patients with SCID than MMRD BMT.

Bone Marrow Transplantation↗
PubMed2006

Defects of class-switch recombination.

Shaping of the secondary antibody repertoire is generated by means of class-switch recombination (CSR), which replaces IgM with other isotypes, and somatic hypermutation (SHM), which allows production of high-affinity antibodies. However, the molecular mechanisms underlying these important processes have long remained obscure. Immunodeficiency with hyper-IgM comprises a group of genetically heterogeneous defects of CSR variably associated with defects of SHM. The study of these patients has allowed us to recognize that both T-cell-B-cell interaction (resulting in CD40-mediated signaling) and intrinsic B-cell mechanisms are involved in CSR and SHM. Elucidation of the molecular defects underlying these disorders has been essential to better understand the molecular basis of Ig diversification and has offered the opportunity to define the clinical spectrum of these diseases and to prompt more accurate diagnostic and therapeutic approaches.

B-Lymphocytes↗
PubMed2006

Omenn syndrome in an infant with IL7RA gene mutation.

Omenn syndrome (OS) is a rare combined immunodeficiency characterized by erythroderma, lymphadenopathy, and autoimmune manifestations. Most cases are due to mutations in the RAG genes. We report a case of OS due to mutations of IL7RA, thus defining Omenn syndrome as a genetically heterogeneous condition.

Amino Acid Substitution↗
PubMed2006

Immunodeficiencies with autoimmune consequences.

Far from being mutually exclusive, immunodeficiency and autoimmunity may occur simultaneously. During the last years, analysis of Autoimmune Polyendocrinopathy--Candidiasis--Ectodermal Dystrophy (APECED) and Immunodysregulation--Polyendocrinopathy--Enteropathy--X-linked (IPEX), two rare monogenic forms of immunodeficiency associated with autoimmunity, has led to the identification of Auto Immune Regulator (AIRE) and Forkhead Box P3 (FOXP3), essential transcriptional regulators, involved in central tolerance and peripheral immune homeostasis, respectively. Characterization of the molecular and cellular mechanisms involved in APECED, and recognition that AIRE expression is sustained by effective thymopoiesis, has recently allowed to define that the autoimmunity of Omenn syndrome, a combined immunodeficiency due to defects of V(D)J recombination, also results from defective expression of AIRE. The implications of identification of the basis of autoimmunity in these rare forms of immunodeficiency have important implications for a better understanding of more common autoimmune disorders, and for development of novel therapeutic approaches.

Animals↗
PubMed2006

Stem cell transplantation in primary immunodeficiencies.

PURPOSE OF REVIEW: To review indications and outcomes of haematopoietic stem cell transplantation in primary immunodeficiencies, in light of recent advances in the field. RECENT FINDINGS: Remarkable improvements in the outcome of haematopoietic stem cell transplantation in primary immunodeficiencies have recently been reported. This is a result of the successful use of alternative donors and more effective strategies to prevent and treat complications. These advances have now permitted the indications for haematopoietic stem cell transplantation to be extended in primary immunodeficiencies. SUMMARY: The optimal results of haematopoietic stem cell transplantation in primary immunodeficiencies have long been obtained with related human leukocyte antigen-identical donors, an option limited to a minority of patients. Transplantation from mismatched related donors has been used with good results mainly in infants with severe combined immune deficiency, but has been associated with significantly delayed or incomplete immune reconstitution. Recent data indicate that transplantation from matched unrelated donors and cord blood transplantation represent valid alternatives, which can be used in all forms of severe primary immunodeficiencies. This, along with careful monitoring of infections, coupled with preemptive treatment, has resulted in a significant improvement in the outcome of haematopoietic stem cell transplantation for severe forms of primary immunodeficiencies.

Cord Blood Stem Cell Transplantation↗
PubMed2005

Damaging-agent sensitivity of Artemis-deficient cell lines.

Defects in repairing double-strand breaks can lead to genome instability and tumorigenesis. In humans, most T(-)B(-) severe combined immunodeficiencies (SCID) have a defect in either the RAG1 or RAG2 gene, are not radiosensitive and do not show genome instability. On the contrary, a minority of T(-)B(-) SCID patients have abnormalities in the Artemis gene and are moderately radiosensitive. Artemis-deficient cells are unable to process hairpin ends after RAG cleavage, but hairpin opening activity alone does not explain the moderate X-ray sensitivity of Artemis-deficient cells. We report here that, at variance with what has been described in mice, cell lines from Artemis(-/-) patients are moderately sensitive to mitomycin C and show only a low to moderate increase in genomic instability, both spontaneously and after exposure to ionizing radiations. There is some heterogeneity in the levels of DNA damage sensitivity and genome instability, which could in part be due to different effects of the specific mutation involved or to genetic background, which may not always represent null alleles. This data supports the hypothesis that, in addition to playing a role in hairpin opening during the V(D)J recombination process, Artemis is involved in the repair of a subset of DNA damage whose exact nature is still undefined.

Animals↗
PubMed2005

Mutational analysis of human BAFF receptor TNFRSF13C (BAFF-R) in patients with common variable immunodeficiency.

BAFF receptor (BAFF-R/BR3/TNFRSF13C) is a recently identified molecule that specifically binds BLyS, a protein belonging to the tumor necrosis factor (TNF) family, and is involved in survival and maturation of B cells. Recent studies have demonstrated that mice defective in BAFF-R gene exhibit an altered profile of the B cell pool, a phenotype observed in BLyS knockout mice as well. These features suggest that mutations in this gene may result in humoral immunodeficiency. To test this hypothesis, we sequenced the BAFF-R gene in 48 patients with common variable immunodeficiency (CVID) along with 57 healthy controls. We have identified three novel variants present at the heterozygous state leading to amino acid substitutions, and have also confirmed the existence of a previously reported intronic variant. The hereby described novel variants were also present in healthy controls and in the healthy patients' parents. These variants do not affect the expression of BAFF-R neither at the mRNA nor at the protein level, suggesting that these variants represent novel polymorphic variants of the BAFF-R gene.

Adolescent↗
PubMed2005

Update on X-linked hypogammaglobulinemia with isolated growth hormone deficiency.

PURPOSE OF REVIEW: To provide an update on the syndrome X-linked hypogammaglobulinemia with isolated growth hormone deficiency, focusing on the pedigree described originally. RECENT FINDINGS: An additional case of X-linked hypogammaglobulinemia with isolated growth hormone deficiency and an unaffected male have been born to a female carrier in the family, allowing improved disease locus mapping. Unpublished research has identified a mutation in the transcription factor myeloid elf-1-like factor that may be the cause of the disease. SUMMARY: X-linked hypogammaglobulinemia with isolated growth hormone deficiency is not caused by Bruton's tyrosine kinase mutations in the family described originally, but may be due to a mutation in myeloid elf-1-like factor.

Agammaglobulinemia↗
PubMed2005

WASP and the phenotypic range associated with deficiency.

PURPOSE OF REVIEW: This review reports on the range of clinical phenotypes that are caused by mutations in the Wiskott-Aldrich Syndrome Protein (WASP) gene. The basis of genotype-phenotype correlation in Wiskott-Aldrich syndrome (WAS) is discussed, with regard to expression of the WAS protein (WASp) and of the effects of WASP mutations on WASp function. Advances in preclinical models of gene therapy for WAS are presented. RECENT FINDINGS: Two recent studies have supported genotype-phenotype correlation in WAS and in related X-linked thrombocytopenia. Expression of the WASp was found to be the best predictor of clinical phenotype. Investigation of autoimmune manifestations associated with WAS has shown that autoimmune hemolytic anemia and elevated serum IgM associate with a more severe clinical course. Finally, while results of hematopoietic stem cell transplantation for WAS continue to improve, several studies have shown the potential benefit of novel therapeutic approaches based on gene transfer. In particular, use of lentiviral vector-driven expression of the WASP gene under autologous promoter sequences has been found to result in increased targeting of hematopoietic stem cells, higher levels of WASp expression, and improved reconstitution of immune function. SUMMARY: Availability of tools that allow analysis of WASp expression has provided evidence for a genotype-phenotype correlation in patients with WASP gene defects. Protein expression is an important prognostic indicator. The molecular and cellular abnormalities of WAS-associated defects are being identified, and significant advances in vector-mediated gene transfer have opened possibilities for the treatment of WAS based on gene therapy.

Anemia, Hemolytic, Autoimmune↗
PubMed2005

Structure and function of the Wiskott-Aldrich syndrome protein.

PURPOSE OF REVIEW: Mutations of the Wiskott-Aldrich syndrome protein can result in highly variable clinical symptoms that affect the hematopoietic/immunologic system. The responsible gene, WASP, has multiple domains, each with unique functions that were only recently fully recognized. RECENT FINDINGS: Two new comprehensive studies of patients with mutations of the Wiskott-Aldrich syndrome protein unequivocally demonstrated a strong phenotype-genotype correlation; the most predictive variable was the presence or absence of the Wiskott-Aldrich syndrome protein in the lymphoid cells from patients with X-linked thrombocytopenia or Wiskott-Aldrich syndrome, respectively. A third clinical study revealed a high rate (>70%) of autoimmune disorders in patients with classic Wiskott-Aldrich syndrome, possibly caused by immune dysregulation involving both T and B cell defects. In addition, the Wiskott-Aldrich syndrome protein is required for natural killer cell function by participating in the formation of immunologic synapses and facilitating the nuclear translocation of nuclear factor for activated T cell and nuclear factor-kappaB. Finally, the Wiskott-Aldrich syndrome protein was shown to play an important role in lymphoid development and in the maturation and function of myelomonocytic cells. SUMMARY: The progress made in dissecting the functions of the Wiskott-Aldrich syndrome protein has direct implications for our understanding of the distinct clinical phenotypes (Wiskott-Aldrich syndrome/X-linked thrombocytopenia; intermittent thrombocytopenia; congenital neutropenia), for making diagnostic and prognostic decisions, and for the selection of therapeutic strategies--from conservative symptomatic treatment to curative hematopoietic stem cell transplantation, or, in the future, gene therapy.

Animals↗
PubMed2005

Jak3, severe combined immunodeficiency, and a new class of immunosuppressive drugs.

The recent elucidation of the multiple molecular mechanisms underlying severe combined immunodeficiency (SCID) is an impressive example of the power of molecular medicine. Analysis of patients and the concomitant generation of animal models mimicking these disorders have quickly provided great insights into the pathophysiology of these potentially devastating illnesses. In this review, we summarize the discoveries that led to the understanding of the role of cytokine receptors and a specific tyrosine kinase, Janus kinase 3 (Jak3), in the pathogenesis of SCID. We discuss how the identification of mutations of Jak3 in autosomal recessive SCID has facilitated the diagnosis of these disorders, offered new insights into the biology of this kinase, permitted new avenues for therapy, and provided the rationale for a generation of a new class of immunosuppressants.

Humans↗