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Genetic variation in schlafen genes in a patient with a recapitulation of the murine Elektra phenotype.

J Allergy Clin Immunol. 2014 May;133(5):1462-5, 1465.e1-5

Authors: Recher M, Karjalainen-Lindsberg ML, Lindlöf M, Söderlund-Venermo M, Lanzi G, Väisänen E, Kumar A, Sadeghi M, Berger CT, Alitalo T, Anttila P, Kolehmainen M, Franssila R, Chen T, Siitonen S, Delmonte OM, Walter JE, Pessach I, Hess C, Simpson MA, Navarini AA, Giliani S, Hedman K, Seppänen M, Notarangelo LD

PMID: 24373355 [PubMed – indexed for MEDLINE]

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Hypomorphic homozygous mutations in phosphoglucomutase 3 (PGM3) impair immunity and increase serum IgE levels.

J Allergy Clin Immunol. 2014 May;133(5):1410-9, 1419.e1-13

Authors: Sassi A, Lazaroski S, Wu G, Haslam SM, Fliegauf M, Mellouli F, Patiroglu T, Unal E, Ozdemir MA, Jouhadi Z, Khadir K, Ben-Khemis L, Ben-Ali M, Ben-Mustapha I, Borchani L, Pfeifer D, Jakob T, Khemiri M, Asplund AC, Gustafsson MO, Lundin KE, Falk-Sörqvist E, Moens LN, Gungor HE, Engelhardt KR, Dziadzio M, Stauss H, Fleckenstein B, Meier R, Prayitno K, Maul-Pavicic A, Schaffer S, Rakhmanov M, Henneke P, Kraus H, Eibel H, Kölsch U, Nadifi S, Nilsson M, Bejaoui M, Schäffer AA, Smith CI, Dell A, Barbouche MR, Grimbacher B

Abstract
BACKGROUND: Recurrent bacterial and fungal infections, eczema, and increased serum IgE levels characterize patients with the hyper-IgE syndrome (HIES). Known genetic causes for HIES are mutations in signal transducer and activator of transcription 3 (STAT3) and dedicator of cytokinesis 8 (DOCK8), which are involved in signal transduction pathways. However, glycosylation defects have not been described in patients with HIES. One crucial enzyme in the glycosylation pathway is phosphoglucomutase 3 (PGM3), which catalyzes a key step in the synthesis of uridine diphosphate N-acetylglucosamine, which is required for the biosynthesis of N-glycans.
OBJECTIVE: We sought to elucidate the genetic cause in patients with HIES who do not carry mutations in STAT3 or DOCK8.
METHODS: After establishing a linkage interval by means of SNPchip genotyping and homozygosity mapping in 2 families with HIES from Tunisia, mutational analysis was performed with selector-based, high-throughput sequencing. Protein expression was analyzed by means of Western blotting, and glycosylation was profiled by using mass spectrometry.
RESULTS: Mutational analysis of candidate genes in an 11.9-Mb linkage region on chromosome 6 shared by 2 multiplex families identified 2 homozygous mutations in PGM3 that segregated with disease status and followed recessive inheritance. The mutations predict amino acid changes in PGM3 (p.Glu340del and p.Leu83Ser). A third homozygous mutation (p.Asp502Tyr) and the p.Leu83Ser variant were identified in 2 other affected families, respectively. These hypomorphic mutations have an effect on the biosynthetic reactions involving uridine diphosphate N-acetylglucosamine. Glycomic analysis revealed an aberrant glycosylation pattern in leukocytes demonstrated by a reduced level of tri-antennary and tetra-antennary N-glycans. T-cell proliferation and differentiation were impaired in patients. Most patients had developmental delay, and many had psychomotor retardation.
CONCLUSION: Impairment of PGM3 function leads to a novel primary (inborn) error of development and immunity because biallelic hypomorphic mutations are associated with impaired glycosylation and a hyper-IgE-like phenotype.

PMID: 24698316 [PubMed – indexed for MEDLINE]

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Complex regional pain syndrome treated with intravenous immunoglobulin in a patient with common variable immune deficiency.

Pain Ther. 2013 Dec;2(2):129-34

Authors: Tachdjian R

Abstract
INTRODUCTION: Common variable immunodeficiency (CVID) represents a large heterogeneous group of antibody-deficiency syndromes associated with a wide range of clinical features and a lack of defined causes in the realm of primary immunodeficiencies. Here, we present a case of CVID in a 62-year-old white male patient with a history of longstanding complex regional pain syndrome (CRPS).
CASE PRESENTATION: His medical history included multiple sinus infections per year and several pneumonias requiring antibiotics. He has had various back surgeries, including a laminectomy at the L4 level 1 year prior to his diagnosis. Thereafter, he underwent four sympathetic nerve blocks with minimal pain relief. Blood chemistries showed a normal white blood cell count with a normal differential, but increased erythrocyte sedimentation rate and C-reactive protein levels. Total Ig (Immunoglobulin)G was 611 mg/dL (normal 700-1,600), IgG1 was 425 mg/dL (341-894), IgG2 was 114 mg/dL (171-632), IgG3 was 14.4 mg/dL (18.4-106), and IgG4 was 7.4 mg/dL (2.4-121). IgA was 47 mg/dL (normal 70-400), IgM was 131 mg/dL (40-230), and IgE was 4.5 kU/L (<4.0). He only had 10 of 23 pneumococcal titers in the protective range post-vaccination. Upon treatment of the CVID with intravenous immunoglobulin, the patient’s pain levels were significantly decreased and have been maintained for more than 2 years.
CONCLUSION: Therefore, immunoglobulin therapy appears to have been beneficial in the treatment of the patient’s symptoms of CRPS, including pain. Additional studies investigating the mechanism by which immunoglobulin therapy may reduce the inflammation and pain of CRPS are needed.

PMID: 25135151 [PubMed]

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Mycobacterium simiae Infection in Two Unrelated Patients with Different Forms of Inherited IFN-γR2 Deficiency.

J Clin Immunol. 2014 Aug 19;

Authors: Martínez-Barricarte R, Megged O, Stepensky P, Casimir P, Moncada-Velez M, Averbuch D, Assous MV, Abuzaitoun O, Kong XF, Pedergnana V, Deswarte C, Migaud M, Rose-John S, Itan Y, Boisson B, Belkadi A, Conti F, Abel L, Vogt G, Boisson-Dupuis S, Casanova JL, Bustamante J

Abstract
Interferon-γ receptor 2 (IFN-γR2) deficiency is a rare primary immunodeficiency characterized by predisposition to infections with weakly virulent mycobacteria, such as environmental mycobacteria and BCG vaccines. We describe here two children with IFN-γR2 deficiency, from unrelated, consanguineous kindreds of Arab and Israeli descent. The first patient was a boy who died at the age of 4.5 years, from recurrent, disseminated disease caused by Mycobacterium simiae. His IFN-γR2 defect was autosomal recessive and complete. The second patient was a girl with multiple disseminated mycobacterial infections, including infection with M. simiae. She died at the age of 5 years, a short time after the transplantation of umbilical cord blood cells from an unrelated donor. Her IFN-γR2 defect was autosomal recessive and partial. Autosomal recessive IFN-γR2 deficiency is life-threatening, even in its partial form, and genetic diagnosis and familial counseling are therefore particularly important for this condition. These two cases are the first of IFN-γR2 deficiency associated with M. simiae infection to be described.

PMID: 25135595 [PubMed – as supplied by publisher]

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Too much of a good thing: immunodeficiency due to hyperactive PI3K signaling.

J Clin Invest. 2014 Aug 18;:1-3

Authors: Walsh CM, Fruman DA

Abstract
Primary immune deficiency diseases arise due to heritable defects that often involve signaling molecules required for immune cell function. Typically, these genetic defects cause loss of gene function, resulting in primary immune deficiencies such as severe combined immune deficiency (SCID) and X-linked agammaglobulinemia (XLA); however, gain-of-function mutations may also promote immune deficiency. In this issue of the JCI, Deau et al. establish that gain-of-function mutations in PIK3R1, which encodes the p85α regulatory subunit of class IA PI3Ks, lead to immunodeficiency. These observations are consistent with previous reports that hyperactivating mutations in PIK3CD, which encodes the p110δ catalytic subunit, are capable of promoting immune deficiency. Mutations that reduce PI3K activity also result in defective lymphocyte development and function; therefore, these findings support the notion that too little or too much PI3K activity leads to immunodeficiency.

PMID: 25133419 [PubMed – as supplied by publisher]

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A human immunodeficiency caused by mutations in the PIK3R1 gene.

J Clin Invest. 2014 Aug 18;

Authors: Deau MC, Heurtier L, Frange P, Suarez F, Bole-Feysot C, Nitschke P, Cavazzana M, Picard C, Durandy A, Fischer A, Kracker S

Abstract
Recently, patient mutations that activate PI3K signaling have been linked to a primary antibody deficiency. Here, we used whole-exome sequencing and characterized the molecular defects in 4 patients from 3 unrelated families diagnosed with hypogammaglobulinemia and recurrent infections. We identified 2 different heterozygous splice site mutations that affect the same splice site in PIK3R1, which encodes the p85α subunit of PI3K. The resulting deletion of exon 10 produced a shortened p85α protein that lacks part of the PI3K p110-binding domain. The hypothetical loss of p85α-mediated inhibition of p110 activity was supported by elevated phosphorylation of the known downstream signaling kinase AKT in patient T cell blasts. Analysis of patient blood revealed that naive T and memory B cell counts were low, and T cell blasts displayed enhanced activation-induced cell death, which was corrected by addition of the PI3Kδ inhibitor IC87114. Furthermore, B lymphocytes proliferated weakly in response to activation via the B cell receptor and TLR9, indicating a B cell defect. The phenotype exhibited by patients carrying the PIK3R1 splice site mutation is similar to that of patients carrying gain-of-function mutations in PIK3CD. Our results suggest that PI3K activity is tightly regulated in T and B lymphocytes and that various defects in the PI3K-triggered pathway can cause primary immunodeficiencies.

PMID: 25133428 [PubMed – as supplied by publisher]

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Lymphocytes subsets reference values in childhood.

Cytometry A. 2014 Aug 6;

Authors: Tosato F, Bucciol G, Pantano G, Putti MC, Sanzari MC, Basso G, Plebani M

Abstract
Immunophenotyping of blood lymphocyte subsets and activation markers is a basic tool in the diagnostic process of primary immunodeficiency diseases, its use becoming more and more widespread as the knowledge about these illnesses increases. However, the availability of reliable reference values, which need to be age-matched for the pediatric population, is a pre-requisite for the reliable interpretation of immunophenotyping data. Aim of this study is to analyze the lymphocyte subsets and activation markers distribution in children aged 0-18 years referring to the University Hospital of Padova and to create age-matched reference values expressed by percentiles, thus providing a valuable guideline for the interpretation of the immunophenotype. © 2014 International Society for Advancement of Cytometry.

PMID: 25132325 [PubMed – as supplied by publisher]

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An unusual cause of recurrent pneumonia in adults.

Lung India. 2014 Jul;31(3):296-8

Authors: Dhir V, Sagar V, Aggarwal A, Rawat A, Singhal M

Abstract
Selective IgM deficiency is a rare primary immunodeficiency defined as isolated low levels of IgM. It presents with recurrent infections and has been described as first presenting in adulthood with recurrent respiratory tract infections. Unlike its better known counterpart of IgA deficiency, this particular immunodeficiency is often overlooked. We present a case of selective IgM deficiency who presented with recurrent respiratory infections.

PMID: 25125825 [PubMed]

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Enhancing Patient Flexibility of Subcutaneous Immunoglobulin G Dosing: Pharmacokinetic Outcomes of Various Maintenance and Loading Regimens in the Treatment of Primary Immunodeficiency.

Biol Ther. 2014 Aug 14;

Authors: Sidhu J, Rojavin M, Pfister M, Edelman J

Abstract
INTRODUCTION: Standard treatment for patients with primary immunodeficiency (PID) is monthly intravenous immunoglobulin (IVIG), or weekly/biweekly subcutaneous immunoglobulin (SCIG) infusion. We used population pharmacokinetic modeling to predict immunoglobulin G (IgG) exposure following a broad range of SCIG dosing regimens for initiation and maintenance therapy in patients with PID.
METHODS: Simulations of SCIG dosing were performed to predict IgG concentration-time profiles and exposure metrics [steady-state area under the IgG concentration-time curve (AUC), IgG peak concentration (C max), and IgG trough concentration (C min) ratios] for various infusion regimens.
RESULTS: The equivalent of a weekly SCIG maintenance dose administered one, two, three, five, or seven times per week, or biweekly produced overlapping steady-state concentration-time profiles and similar AUC, C max, and C min values [95% confidence interval (CI) for ratios was 0.98-1.03, 0.95-1.09, and 0.92-1.08, respectively]. Administration every 3 or 4 weeks resulted in higher peaks and lower troughs; the 95% CI of the AUC, C max, and C min ratios was 0.97-1.04, 1.07-1.26, and 0.86-0.95, respectively. IgG levels >7 g/L were reached within 1 week using a loading dose regimen in which the weekly maintenance dose was administered five times in the first week of treatment. In patients with very low endogenous IgG levels, administering 1.5 times the weekly maintenance dose five times in the first week of treatment resulted in a similar response.
CONCLUSIONS: The same total weekly SCIG dose can be administered at different intervals, from daily to biweekly, with minimal impact on serum IgG levels. Several SCIG loading regimens rapidly achieve adequate serum IgG levels in treatment-naïve patients.

PMID: 25118975 [PubMed – as supplied by publisher]

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Pulmonary manifestations of primary immunodeficiency disorders in children.

Front Pediatr. 2014;2:77

Authors: Jesenak M, Banovcin P, Jesenakova B, Babusikova E

Abstract
Primary immunodeficiencies (PIDs) are inherited disorders in which one or several components of immune system are decreased, missing, or of non-appropriate function. These diseases affect the development, function, or morphology of the immune system. The group of PID comprises more than 200 different disorders and syndromes and the number of newly recognized and revealed deficiencies is still increasing. Their clinical presentation and complications depend on the type of defects and there is a great variability in the relationship between genotypes and phenotypes. A variation of clinical presentation across various age categories is also presented and children could widely differ from adult patients with PID. Respiratory symptoms and complications present a significant cause of morbidity and also mortality among patients suffering from different forms of PIDs and they are observed both in children and adults. They can affect primarily either upper airways (e.g., sinusitis and otitis media) or lower respiratory tract [e.g., pneumonia, bronchitis, bronchiectasis, and interstitial lung diseases (ILDs)]. The complications from lower respiratory tract are usually considered to be more important and also more specific for PIDs and they determinate patients’ prognosis. The spectrum of the causal pathogens usually demonstrates typical pattern characteristic for each PID category. The respiratory signs of PIDs can be divided into infectious (upper and lower respiratory tract infections and complications) and non-infectious (ILDs, bronchial abnormalities – especially bronchiectasis, malignancies, and benign lymphoproliferation). Early diagnosis and appropriate therapy can prevent or at least slow down the development and course of respiratory complications of PIDs.

PMID: 25121077 [PubMed]

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