Research

DOCK8 Drives Src-Dependent NK Cell Effector Function.

J Immunol. 2017 Aug 09;:

Authors: Kearney CJ, Vervoort SJ, Ramsbottom KM, Freeman AJ, Michie J, Peake J, Casanova JL, Picard C, Tangye SG, Ma CS, Johnstone RW, Randall KL, Oliaro J

Abstract
Mutations in the dedicator of cytokinesis 8 (DOCK8) gene cause an autosomal recessive form of hyper-IgE syndrome, characterized by chronic immunodeficiency with persistent microbial infection and increased incidence of malignancy. These manifestations suggest a defect in cytotoxic lymphocyte function and immune surveillance. However, how DOCK8 regulates NK cell-driven immune responses remains unclear. In this article, we demonstrate that DOCK8 regulates NK cell cytotoxicity and cytokine production in response to target cell engagement or receptor ligation. Genetic ablation of DOCK8 in human NK cells attenuated cytokine transcription and secretion through inhibition of Src family kinase activation, particularly Lck, downstream of target cell engagement or NKp30 ligation. PMA/Ionomycin treatment of DOCK8-deficient NK cells rescued cytokine production, indicating a defect proximal to receptor ligation. Importantly, NK cells from DOCK8-deficient patients had attenuated production of IFN-γ and TNF-α upon NKp30 stimulation. Taken together, we reveal a novel molecular mechanism by which DOCK8 regulates NK cell-driven immunity.

PMID: 28794229 [PubMed – as supplied by publisher]

Powered by WPeMatico

Uses of Next-Generation Sequencing Technologies for the Diagnosis of Primary Immunodeficiencies.

Front Immunol. 2017;8:847

Authors: Seleman M, Hoyos-Bachiloglu R, Geha RS, Chou J

Abstract
Primary immunodeficiencies (PIDs) are genetic disorders impairing host immunity, leading to life-threatening infections, autoimmunity, and/or malignancies. Genomic technologies have been critical for expediting the discovery of novel genetic defects underlying PIDs, expanding our knowledge of the complex clinical phenotypes associated with PIDs, and in shifting paradigms of PID pathogenesis. Once considered Mendelian, monogenic, and completely penetrant disorders, genomic studies have redefined PIDs as a heterogeneous group of diseases found in the global population that may arise through multigenic defects, non-germline transmission, and with variable penetrance. This review examines the uses of next-generation DNA sequencing (NGS) in the diagnosis of PIDs. While whole genome sequencing identifies variants throughout the genome, whole exome sequencing sequences only the protein-coding regions within a genome, and targeted gene panels sequence only a specific cohort of genes. The advantages and limitations of each sequencing approach are compared. The complexities of variant interpretation and variant validation remain the major challenge in wide-spread implementation of these technologies. Lastly, the roles of NGS in newborn screening and precision therapeutics for individuals with PID are also addressed.

PMID: 28791010 [PubMed]

Powered by WPeMatico

Prospective Study of a Cohort of Russian Nijmegen Breakage Syndrome Patients Demonstrating Predictive Value of Low Kappa-Deleting Recombination Excision Circle (KREC) Numbers and Beneficial Effect of Hematopoietic Stem Cell Transplantation (HSCT).

Front Immunol. 2017;8:807

Authors: Deripapa E, Balashov D, Rodina Y, Laberko A, Myakova N, Davydova NV, Gordukova MA, Abramov DS, Pay GV, Shelikhova L, Prodeus AP, Maschan MA, Maschan AA, Shcherbina A

Abstract
BACKGROUND: Nijmegen breakage syndrome (NBS) is a combined primary immunodeficiency with DNA repair defect, microcephaly, and other phenotypical features. It predominantly occurs in Slavic populations that have a high frequency of carriers with the causative NBN gene c.657_661del5 mutation. Due to the rarity of the disease in the rest of the world, studies of NBS patients are few. Here, we report a prospective study of a cohort of Russian NBS patients.
METHODS: 35 Russian NBS patients of ages 1-19 years, referred to our Center between years 2012 and 2016, were prospectively studied.
RESULTS: Despite the fact that in 80% of the patients microcephaly was diagnosed at birth or shortly thereafter, the average delay of NBS diagnosis was 6.5 years. Though 80% of the patients had laboratory signs of immunodeficiency, only 51% of the patients experienced significant infections. Autoimmune complications including interstitial lymphocytic lung disease and skin granulomas were noted in 34%, malignancies-in 57% of the patients. T-cell excision circle (TREC)/kappa-deleting recombination excision circle (KREC) levels were low in the majority of patients studied. Lower KREC levels correlated with autoimmune and oncological complications. Fifteen patients underwent hematopoietic stem cell transplantation (HSCT), 10 of them were alive and well, with good graft function. Three patients in the HSCT group and five non-transplanted patients died; tumor progression being the main cause of death. The probability of the overall survival since NBS diagnosis was 0.76 in the HSCT group and 0.3 in the non-transplanted group.
CONCLUSION: Based on our findings of low TRECs in most NBS patients, independent of their age, TREC detection can be potentially useful for detection of NBS patients during neonatal screening. KREC concentration can be used as a prognostic marker of disease severity. HSCT is a viable treatment option in NBS and should be especially considered in patients with low KREC numbers early on, before development of life-threatening complications.

PMID: 28791007 [PubMed]

Powered by WPeMatico

Facilitated Subcutaneous Immunoglobulin (fSCIg) in Autoimmune Cytopenias Associated with Common Variable Immunodeficiency.

Isr Med Assoc J. 2017 Jul;19(7):420-423

Authors: Pedini V, Savore I, Giovanna Danieli M

Abstract
BACKGROUND: Common variable immunodeficiency (CVID) is the most common symptomatic primary immune deficiency of adulthood. Besides recurrent infections, autoimmune disorders-mainly cytopenias-affect 30% of patients with CVID.
OBJECTIVES: To describe the efficacy and safety of facilitated subcutaneous immunoglobulin (fSCIg), which is a combination of 10% [human] SCIg with recombinant human hyaluronidase for the treatment of CVID-linked cytopenias.
METHODS: We describe four women (mean age 54 years) with CVID associated with idiopathic thrombocytopenic purpura (ITP) (n=3) and autoimmune hemolytic anemia (AIHA) (n=1). Diagnosis of CVID was made according to the European Society of Immune Deficiencies / Pan-American Group for Immune Deficiency criteria. All were treated with fSCIg (bi-monthly, 20 g).
RESULTS: After a median follow-up of 22 months, all patients achieved a stable remission from the cytopenias, characterized by increased platelet values in ITP (mean values 93000/mmc), and resolution of anemia. A reduction of the daily prednisone dose was documented in the patient with AIHA. No systemic adverse drug reactions were observed.
CONCLUSIONS: Our preliminary data documented the efficacy and safety of fSCIg in the treatment of CVID associated with autoimmune cytopenias, with a good tolerability. We also noted the role of fSCIg as a steroid sparing agent. It is thus possible to suppose an immunomodulatory role for fSCIg, but linked to different mechanisms than IVIg, due to the peculiar pharmacokinetic and administration route of fSCIg.

PMID: 28786256 [PubMed – in process]

Powered by WPeMatico

Common Variable Immunodeficiency and Liver Involvement.

Clin Rev Allergy Immunol. 2017 Aug 07;:

Authors: Song J, Lleo A, Yang GX, Zhang W, Bowlus CL, Eric Gershwin M, Leung PSC

Abstract
Common variable immunodeficiency (CVID) is a primary B-cell immunodeficiency disorder, characterized by remarkable hypogammaglobulinemia. The disease can develop at any age without gender predominance. The prevalence of CVID varies widely worldwide. The underlying causes of CVID remain largely unknown; primary B-cell dysfunctions, defects in T cells and antigen-presenting cells are involved. Although some monogenetic defects have been identified in some CVID patients, it is likely that CVID is polygenic. Patients with CVID develop recurrent and chronic infections (e.g., bacterial infections of the respiratory or gastrointestinal tract), autoimmune diseases, lymphoproliferation, malignancies, and granulomatous lesions. Interestingly, autoimmunity can be the only clinical manifestation of CVID at the time of diagnosis and may even develop prior to hypogammaglobulinemia. The diagnosis of CVID is largely based on the criteria established by European Society for Immunodeficiencies and Pan-American Group for Immunodeficiency (ESID/PAGID) and with some recent modifications. The disease can affect multiple organs, including the liver. Clinical features of CVID patients with liver involvement include abnormal liver biochemistries, primarily elevation of alkaline phosphatase (ALP), nodular regenerative hyperplasia (NRH), or liver cirrhosis and its complications. Replacement therapy with immunoglobulin (Ig) and anti-infection therapy are the primary treatment regimen for CVID patients. No specific therapy for liver involvement of CVID is currently available, and liver transplantation is an option only in select cases. The prognosis of CVID varies widely. Further understanding in the etiology and pathophysiology will facilitate early diagnosis and treatments to improve prognosis.

PMID: 28785926 [PubMed – as supplied by publisher]

Powered by WPeMatico

Emerging Infections and Pertinent Infections Related to Travel for Patients with Primary Immunodeficiencies.

J Clin Immunol. 2017 Aug 07;:

Authors: Sullivan KE, Bassiri H, Bousfiha AA, Costa-Carvalho BT, Freeman AF, Hagin D, Lau YL, Lionakis MS, Moreira I, Pinto JA, de Moraes-Pinto MI, Rawat A, Reda SM, Reyes SOL, Seppänen OM, Tang MLK

Abstract
In today’s global economy and affordable vacation travel, it is increasingly important that visitors to another country and their physician be familiar with emerging infections, infections unique to a specific geographic region, and risks related to the process of travel. This is never more important than for patients with primary immunodeficiency disorders (PIDD). A recent review addressing common causes of fever in travelers provides important information for the general population Thwaites and Day (N Engl J Med 376:548-560, 2017). This review covers critical infectious and management concerns specifically related to travel for patients with PIDD. This review will discuss the context of the changing landscape of infections, highlight specific infections of concern, and profile distinct infection phenotypes in patients who are immune compromised. The organization of this review will address the environment driving emerging infections and several concerns unique to patients with PIDD. The first section addresses general considerations, the second section profiles specific infections organized according to mechanism of transmission, and the third section focuses on unique phenotypes and unique susceptibilities in patients with PIDDs. This review does not address most parasitic diseases. Reference tables provide easily accessible information on a broader range of infections than is described in the text.

PMID: 28786026 [PubMed – as supplied by publisher]

Powered by WPeMatico

Development of fresh and vitrified agouti ovarian tissue after xenografting to ovariectomised severe combined immunodeficiency (SCID) mice.

Reprod Fertil Dev. 2017 Aug 08;:

Authors: Praxedes ÉCG, Lima GL, Bezerra LGP, Santos FA, Bezerra MB, Guerreiro DD, Rodrigues APR, Domingues SFS, Silva AR

Abstract
The aim of the present study was to evaluate the development of fresh and vitrified agouti ovarian tissue after xenografting to C57Bl/6 severe combined immunodeficiency (SCID) female mice. Ovaries were obtained from five female agoutis and divided into 16 fragments. Five fragments were transplanted immediately to ovariectomised SCID mice and the others were vitrified, stored for 2 weeks and transplanted only after rewarming. Tissue fragments were transplanted under the kidney capsule in recipients. The return of ovarian activity in recipients was monitored by the observation of external signs of oestrus and vaginal cytology over a period of 40 days after transplantation, after which the grafts were removed and evaluated for morphology, cell proliferation and the occurrence of DNA fragmentation. Ovarian activity returned in four of five mice that received fresh ovarian tissue from agoutis and in one of six mice that had received vitrified tissue a mean (±s.e.m.) 20.6±8.6 days after xenotransplantation. After graft removal, a predominance of primordial and primary follicles was observed in all grafts. Vitrification reduced cell proliferation and increased the occurrence of DNA fragmentation in grafted agouti ovarian tissue. In conclusion, the present study demonstrates that xenografted agouti ovarian tissue, fresh or vitrified, is able to promote the return of ovarian activity in ovariectomised SCID C57B1/6 mice. However, improvements to vitrification protocols for agouti ovarian tissue are necessary.

PMID: 28784201 [PubMed – as supplied by publisher]

Powered by WPeMatico

It’s all in the family.

Sci Immunol. 2017 Mar 03;2(9):

Authors: Griffin GK

Abstract
CD70-deficiency causes primary immunodeficiency and susceptibility to EBV-driven lymphoma.

PMID: 28783700 [PubMed]

Powered by WPeMatico