Research

A New IL-2RG Gene Mutation in an X-linked SCID Identified through TREC/KREC Screening: a Case Report.

Iran J Allergy Asthma Immunol. 2015 Aug;14(4):457-461

Authors: Nourizadeh M, Borte S, Fazlollahi M, Hammarström L, Pourpak Z

Abstract
Severe combined immunodeficiency (SCID) represents a rare group of primary immunodeficiency disorders (PIDs), with known or unknown genetic alterations. Here, we report a new interleukin 2 receptor, gamma chain (IL-2RG) mutation in an Iranian SCID newborn.The patient was a 6-day old boy with a family history of PID. The child was screened using a molecular-based analysis for the assessment of T cell receptor excision circles (TRECs) and kappa-deleting recombination excision circles (KRECs). Moreover, a complete immunological evaluation and gene sequencing was performed.Results showed undetectable TREC but a high level of KREC copy numbers. Flowcytometric data indicated low numbers of T and NK cells, but elevated number of B cells. A novel substitution in IL2RG: c.675 C>A, leading to p.225 Ser>Arg was found. Based on the functional analysis, the mutation is predicted to be damaging. The patient was diagnosed as a T B+ NK X-linked SCID.

PMID: 26547715 [PubMed – as supplied by publisher]

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Development of a duplex real-time RT-qPCR assay to monitor genome replication, gene expression and gene insert stability during in vivo replication of a prototype live attenuated canine distemper virus vector encoding SIV gag.

J Virol Methods. 2015 Mar;213:26-37

Authors: Coleman JW, Wright KJ, Wallace OL, Sharma P, Arendt H, Martinez J, DeStefano J, Zamb TP, Zhang X, Parks CL

Abstract
Advancement of new vaccines based on live viral vectors requires sensitive assays to analyze in vivo replication, gene expression and genetic stability. In this study, attenuated canine distemper virus (CDV) was used as a vaccine delivery vector and duplex 2-step quantitative real-time RT-PCR (RT-qPCR) assays specific for genomic RNA (gRNA) or mRNA have been developed that concurrently quantify coding sequences for the CDV nucleocapsid protein (N) and a foreign vaccine antigen (SIV Gag). These amplicons, which had detection limits of about 10 copies per PCR reaction, were used to show that abdominal cavity lymphoid tissues were a primary site of CDV vector replication in infected ferrets, and importantly, CDV gRNA or mRNA was undetectable in brain tissue. In addition, the gRNA duplex assay was adapted for monitoring foreign gene insert genetic stability during in vivo replication by analyzing the ratio of CDV N and SIV gag genomic RNA copies over the course of vector infection. This measurement was found to be a sensitive probe for assessing the in vivo genetic stability of the foreign gene insert.

PMID: 25486083 [PubMed – indexed for MEDLINE]

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[A survey of HTLV-1 carrier clinics in Japan].

Rinsho Ketsueki. 2015 Jun;56(6):666-72

Authors: Ishitsuka K, Yamano Y, Utsunomiya A, Uchimaru K

Abstract
Human T-lymphotropic virus type-I (HTLV-1) is the causative agent of adult T-cell leukemia/lymphoma and HTLV-1 associated myelopathy/tropical spastic paraparesis. Currently, mother-to-child transmission via breastfeeding and sexual intercourse are considered to be the two major routes for HTLV-1 infection. We surveyed four clinics in Japan (two HTLV-1 carrier clinics in non-endemic areas and one in an endemic area, and one hematology clinic in a highly endemic area) and reviewed the management of carriers. In HTLV-1 carrier clinics, more than half of visitors had learned of their infections based on an examination conducted either for blood donation or pregnancy. Although half of visitors had known of their infection more than 2 years prior to their visit, they became to visit the clinics probably due to recent awareness of HTLV-1 in public and of carrier clinics. They requested a detailed explanation, and check-ups for infection and its related diseases. In contrast, most visitors in highly endemic areas had apparently received good explanations from their primary care physicians. It is noteworthy that neither parent of more than half of the carriers who visited the two clinics in the non-endemic area had been born outside of Kyushu, a highly endemic area, indicating that carriers will disperse from known endemic areas. Configuring an appropriate and efficient system to support carriers is necessary, especially in non-endemic areas.

PMID: 26256877 [PubMed – indexed for MEDLINE]

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Socioeconomic Impact of Immunoglobulin Replacement Therapy for Primary Immunodeficiency Patients on the Health Public System in Brazil: A Single Center Study.

Value Health. 2015 Nov;18(7):A878

Authors: Carmo EV, Correa M, Mazzucchelli JL, Tavares L, Damasceno E, Costa-Carvalho BT

PMID: 26534705 [PubMed – in process]

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Increased serum IgM, immunodeficiency, and autoimmunity: A clinical series.

Int J Immunopathol Pharmacol. 2015 Dec;28(4):547-56

Authors: Picchianti Diamanti A, Rosado MM, Scarsella M, Ceccarelli S, Laganà B, D’Amelio R, Carsetti R

Abstract
BACKGROUND: Primary immunodeficiencies (PIDs) are generally characterized by recurrent infections; however they may be complicated by other clinical disorders such as allergy, autoimmunity, and lymphoproliferation. In particular, autoimmunity may be the first manifestation of the disease in patients with low serum immunoglobulins (Ig) levels. Here we describe a group of patients that share features of immunodeficiency and autoimmunity.
MATERIALS AND METHODS: All patients went through a complete T and B cell subset characterization and a B cell function analysis in the peripheral blood by flow-cytometry. B cell proliferation and plasma cell differentiation was measured, in vitro, after CpG stimulation for 7 days as previously described. Semi-quantitative PCR analysis for AID and UNG expression as well as serum levels of BAFF were carried out in order to better define the diagnosis.
RESULTS: Immunological and molecular analysis did not lead to the identification of known molecular defect typical of Hyper IgM syndrome. A comparative study of the peripheral blood B cell subsets between patients and healthy donors showed that in patients with autoimmune manifestations all circulating B cells expressed high amounts of surface IgM.
CONCLUSIONS: These results suggest that the increased IgM expression on circulating B cells, reflecting B cell activation, might identify a clinical condition characterized by hyper IgM serum levels of unknown molecular defects, associated with susceptibility to infections and autoimmunity.

PMID: 26526204 [PubMed – in process]

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[Integration of Internal and Clinical Laboratory Medicine].

Rinsho Byori. 2015 Mar;63(3):392-6

Authors: Hirokawa M

Abstract
The mission of our department is to contribute to diagnostic improvement in medicine in order to promote better outcomes. We have clinical expertise in internal medicine including primary care medicine, hematology, allergy, rheumatology, and nephrology. We also have expertise in clinical laboratory medicine and hospital infection control. Specific areas of academic interest include immune-mediated hematological diseases, allergic diseases, autoimmune diseases, and chronic kidney disease. Immune recovery following hematopoietic stem cell transplantation and the immunopathophysiology of bone marrow failure syndrome have been our main topics of interest, and we have been applying our knowledge of T-cell receptor diversity to these areas in order to explore the mechanisms of immunodeficiency and autoimmunity in hematological disorders. We have found that the peripheral expansion of mature T cells in grafts plays an important role in immune reconstitution after stem cell transplantation in humans, and have also found altered T-cell repertoires in immune-mediated chronic acquired pure red cell aplasia. Thus, quantitative and qualitative analyses of immune receptors could be a promising method for assessing immunocompetence and exploring the pathophysiology of autoimmune diseases. Research and development of novel approaches in this field should be intensively conducted.

PMID: 26524863 [PubMed – in process]

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Eliminating SCID row: new approaches to SCID.

Hematology Am Soc Hematol Educ Program. 2014 Dec 5;2014(1):475-80

Authors: Kohn DB

Abstract
Treatments for patients with SCID by hematopoietic stem cell transplantation (HSCT) have changed this otherwise lethal primary immune deficiency disorder into one with an increasingly good prognosis. SCID has been the paradigm disorder supporting many key advances in the field of HSCT, with first-in-human successes with matched sibling, haploidentical, and matched unrelated donor allogeneic transplantations. Nevertheless, the optimal approaches for HSCT are still being defined, including determining the optimal stem cell sources, the use and types of pretransplantation conditioning, and applications for SCID subtypes associated with radiosensitivity, for patients with active viral infections and for neonates. Alternatively, autologous transplantation after ex vivo gene correction (gene therapy) has been applied successfully to the treatment of adenosine deaminase-deficient SCID and X-linked SCID by vector-mediated gene addition. Gene therapy holds the prospect of avoiding risks of GVHD and would allow each patient to be their own donor. New approaches to gene therapy by gene correction in autologous HSCs using site-specific endonuclease-mediated homology-driven gene repair are under development. With newborn screening becoming more widely adopted to detect SCID patients before they develop complications, the prognosis for SCID is expected to improve further. This chapter reviews recent advances and ongoing controversies in allogeneic and autologous HSCT for SCID.

PMID: 25696897 [PubMed – indexed for MEDLINE]

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Compound heterozygous mutations in the noncoding RNU4ATAC cause Roifman Syndrome by disrupting minor intron splicing.

Nat Commun. 2015;6:8718

Authors: Merico D, Roifman M, Braunschweig U, Yuen RK, Alexandrova R, Bates A, Reid B, Nalpathamkalam T, Wang Z, Thiruvahindrapuram B, Gray P, Kakakios A, Peake J, Hogarth S, Manson D, Buncic R, Pereira SL, Herbrick JA, Blencowe BJ, Roifman CM, Scherer SW

Abstract
Roifman Syndrome is a rare congenital disorder characterized by growth retardation, cognitive delay, spondyloepiphyseal dysplasia and antibody deficiency. Here we utilize whole-genome sequencing of Roifman Syndrome patients to reveal compound heterozygous rare variants that disrupt highly conserved positions of the RNU4ATAC small nuclear RNA gene, a minor spliceosome component that is essential for minor intron splicing. Targeted sequencing confirms allele segregation in six cases from four unrelated families. RNU4ATAC rare variants have been recently reported to cause microcephalic osteodysplastic primordial dwarfism, type I (MOPD1), whose phenotype is distinct from Roifman Syndrome. Strikingly, all six of the Roifman Syndrome cases have one variant that overlaps MOPD1-implicated structural elements, while the other variant overlaps a highly conserved structural element not previously implicated in disease. RNA-seq analysis confirms extensive and specific defects of minor intron splicing. Available allele frequency data suggest that recessive genetic disorders caused by RNU4ATAC rare variants may be more prevalent than previously reported.

PMID: 26522830 [PubMed – in process]

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Impaired RASGRF1/ERK-mediated GM-CSF response characterizes CARD9 deficiency in French-Canadians.

J Allergy Clin Immunol. 2015 Oct 29;

Authors: Gavino C, Hamel N, Zeng JB, Legault C, Guiot MC, Chankowsky J, Lejtenyi D, Lemire M, Alarie I, Dufresne S, Boursiquot JN, McIntosh F, Langelier M, Behr MA, Sheppard DC, Foulkes WD, Vinh DC

Abstract
BACKGROUND: Caspase recruitment domain-containing protein 9 (CARD9) deficiency is an autosomal recessive primary immunodeficiency conferring human susceptibility to invasive fungal disease, including spontaneous central nervous system candidiasis (sCNSc). However, clinical characterization of sCNSc is variable, hindering its recognition. Furthermore, an in-depth understanding of the bases for this susceptibility has remained elusive.
OBJECTIVES: We sought to comprehensively characterize sCNSc and to dissect the mechanisms by which a hypomorphic CARD9 mutation causes susceptibility to Candida species.
METHODS: We describe the clinical and radiologic findings of sCNSc caused by CARD9 deficiency in a French-Canadian cohort. We performed genetic, cellular, and molecular analyses to further decipher its pathophysiology.
RESULTS: In our French-Canadian series (n = 4) sCNSc had onset in adulthood (median, 38 years) and was often misinterpreted radiologically as brain malignancies; 1 patient had additional novel features (eg, endophthalmitis and osteomyelitis). CARD9 deficiency resulted from a hypomorphic p.Y91H mutation and allelic imbalance established in this population through founder effects. We demonstrate a consistent cellular phenotype of impaired GM-CSF responses. The ability of CARD9 to complex with B-cell CLL/lymphoma 10 (BCL10) and mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1) is intact in our series, arguing against its involvement in susceptibility to fungi. Instead, we show that the p.Y91H mutation impairs the ability of CARD9 to complex with Ras protein-specific guanine nucleotide-releasing factor 1 (RASGRF1), leading to impaired activation of nuclear factor κB and extracellular signal-regulated kinase (ERK) in monocytes and subsequent GM-CSF responses. Successful treatment of a second patient with adjunctive GM-CSF bolsters the clinical relevance of these findings.
CONCLUSIONS: Hypomorphic CARD9 deficiency caused by p.Y91H results in adult-onset disease with variable penetrance and expressivity. Our findings establish the CARD9/RASGRF1/ERK/GM-CSF axis as critical to the pathophysiology of sCNSc.

PMID: 26521038 [PubMed – as supplied by publisher]

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Generation of switched memory B cells in response to vaccination in Down syndrome children and their siblings.

Vaccine. 2015 Oct 27;

Authors: Valentini D, Marcellini V, Bianchi S, Villani A, Facchini M, Donatelli I, Castrucci MR, Marasco E, Farroni C, Carsetti R

Abstract
BACKGROUND: Immunodeficiency is an integral aspect of Down syndrome, as demonstrated by the increased susceptibility to infection of affected. Mortality is still higher than in general population, with respiratory infections among the major causes of death. As more people with Down syndrome are living today than ever before, it is indispensable to develop strategies to prevent and cure the associated disorders. Vaccination is the most successful instrument of preventive medicine. Special seasonal influenza and pneumococcal vaccination strategies have been designed for individuals with risk conditions of all ages. Down syndrome individuals are not included in the high-risk categories.
METHODS: We enrolled in our study 15 children with Down syndrome and their siblings, vaccinated for the first time with seasonal influenza vaccine and receiving a booster dose of a glyco-conjugated pneumococcal vaccine. We compared the immunological features and response to vaccination measuring serum antibody titers and frequency of specific memory B cells.
RESULTS: We confirm that a severe reduction of switched memory B cells is always associated to Down syndrome. After primary vaccination Down syndrome children generate significantly less specific switched memory B cells than their siblings. The response to a booster dose of vaccine is instead comparable in both groups. The production of specific antibodies was equally effective in Down syndrome and controls both after primary and secondary immunization.
CONCLUSIONS: Down syndrome individuals should be considered a high risk group, because of their increased susceptibility to infection and reduced number of switched memory B cells. Tailored vaccination protocols are needed in order to reduce their burden of infections throughout life.

PMID: 26518399 [PubMed – as supplied by publisher]

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