Combined Immune Deficiency in a Patient with a Novel NFKB2 Mutation

NFKB2 encodes the p100/p52 protein, a critical mediator of the canonical and noncanonical NFkB signaling pathways. Here we report the comprehensive immune evaluation of a child with a novel NFKB2 mutation and provide evidence that aberrant NFKB2 signaling not only causes humoral immune deficiency, but also interferes with the TCR-mediated proliferation of T cells. These observations expand the known phenotype associated with NFKB2 mutations.     

Hyper IgM Syndrome: a Report from the USIDNET Registry

Purpose

The United States Immunodeficiency Network (USIDNET) patient registry was used to characterize the presentation, genetics, phenotypes, and treatment of patients with Hyper IgM Syndrome (HIGM).

Methods

The USIDNET Registry was queried for HIGM patient data collected from October 1992 to July 2015. Data fields included demographics, criteria for diagnosis, pedigree analysis, mutations, clinical features, treatment and transplant records, laboratory findings, and mortality.

Results

Fifty-two physicians entered data from 145 patients of ages 2 months to 62 years (median 12 years); 131 were males. Using patients’ age at last entry, data from 2072 patient years are included. Mutations were recorded for 85 subjects; 82 were in CD40LG. Eighteen subjects had non-X-linked HIGM. 40 % had a normal serum IgM and 15 %, normal IgA. Infections were reported for 91 %, with pulmonary, ear, and sinus infections being the most common. 42 % had Pneumocystis jirovecii pneumonia; 6 % had Cryptosporidium. 41 % had neutropenia. 78 % experienced non-infectious complications: chronic diarrhea (n?=?22), aphthous ulcers (n?=?28), and neoplasms (n?=?8) including colon cancer, adrenal adenoma, liver adenocarcinoma, pancreatic carcinoid, acute myeloid leukemia, hepatoma, and, in a female with an autosomal dominant gain of function mutation in PIK3CD, an ovarian dysgerminoma. Thirteen patients had a hematopoietic marrow or stem cell transplant; three had solid organ transplants. Thirteen were known to have died (median age?=?14 years).

Conclusions

Analysis of the USIDNET Registry provides data on the common clinical features of this rare syndrome, and in contrast with previously published data, demonstrates longer survival times and reduced gastrointestinal manifestations.

     

Neutrophil Functions in Immunodeficiency Due to DOCK8 Deficiency

Neutrophil chemotactic defects have been reported previously in patients with hyper-IgE syndrome. Bi-allelic mutations in dedicator of cytokinesis 8 (DOCK8) gene usually cause an autosomal recessive hyper-IgE syndrome phenotype. Data are lacking about expression of DOCK8 protein in neutrophils or the possible role of DOCK8 in neutrophil function. We sought to determine if DOCK8 protein is expressed in neutrophils and if DOCK8 plays a role in neutrophil function. The expression of DOCK8 protein was assessed in neutrophils from healthy volunteers with and without activators. Neutrophil chemotaxis, phagocytosis and superoxide generation were studied in neutrophils from DOCK8-deficient patients compared to neutrophils from healthy controls before and after stimulation with activators: phorbol 12-myristate 13-acetate (PMA) or N-Formylmethionyl-leucyl-phenylalanine (fMLP). DOCK8 protein is expressed in resting neutrophils from healthy controls, with a significant increase in DOCK8 expression after stimulation. Neutrophil functions were assessed in 6 DOCK8-deficient patients. All patients had the same non-sense mutation (c.C5134A, p.S1711X). Normal chemotaxis was recorded in 4/6 patients while a mild to moderate chemotaxis defect was recorded in 2/6. Superoxide generation was mainly normal in neutrophils from all six patients and phagocytosis was normal in five patients tested. We conclude that DOCK8 protein is expressed in resting human neutrophils and DOCK8 expression is increased after stimulation with either PMA or fMLP. Most patients with a disease-causing mutation in DOCK8 have normal neutrophil functions, while a minority showed a mild to moderate chemotactic defect.     

Novel Case of Tripeptidyl Peptidase 2 Deficiency Associated with Mild Clinical Phenotype

Journal of Clinical Immunology -     

Genetic Analysis of Patients with Two Different Types of Hyper IgM Syndrome

ABSTRACT

Background: Hyper IgM Syndrome (HIGM) is a rare primary immunodeficiency in which impairment of class switching recombination (CSR) and somatic hyper-mutation (SHM) leads to recurrent infections.

Objectives: The aim of this study is to report the clinical and genetic features of six Iranian HIGM patients.

Methods: Six patients, who suspected to have HIGM based on two clinical findings, including recurrent infections and low levels of IgG and IgA and normal or elevated levels of IgM, were entered this study to undergo genetic studies. Sanger sequencing was applied to detect pathogenic mutations in CD40L and AID genes causing two most common forms of HIGM, which known as HIGM type 1 and 2, respectively.

Results: All patients who entered the study were males from unrelated families with a median age of 3.8 years. The most frequent clinical manifestation was recurrent pneumonia. Genetic studies of the patients revealed six different mutations, including five mutations in CD40L besides one mutation in AID. Two mutations in CD40L (p.F31fsX5 and p.C84S) were novel and three mutations (p. G219R, p.D62fsX18, and p.Q186X) have been previously reported. The mutation found in AID (p.E122X) was also previously described.

Conclusion: The study results may provide valuable information for prenatal diagnosis and also for genetic counseling especially for those who have a history of primary immunodeficiency in their family.     

Role of DOCK2 and DOCK180 in fetal thymus colonization

Fetal thymus colonization is initiated before the vascularization of the thymus primordium. This prevascular colonization of the fetal thymus by T‐lymphoid progenitor cells is guided by the coordination of CCR7‐ and CCR9‐mediated chemokine signals. However, the intracellular signals that mediate the prevascular migration of T‐lymphoid progenitor cells to the fetal thymus are unknown. Here we show that T‐lymphoid progenitor cells in fetal mice express two closely related CDM family molecules, DOCK2 and DOCK180. We found that the prevascular fetal thymus accumulation in vivo was significantly reduced in mice doubly deficient for DOCK2 and DOCK180 but not in mice deficient for either DOCK2 or DOCK180. Immature T‐lymphoid cells from mice doubly deficient for DOCK2 and DOCK180 were defective in their in vitro migration towards fetal thymus lobes. The T‐lymphoid progenitor cells generated in mice lacking DOCK2 and DOCK180 were capable of T‐cell development after their transfer into a fetal thymus environment, and the impaired fetal thymus colonization in mice deficient for DOCK2 and DOCK180 was not as severe as that in mice doubly deficient for CCR7 and CCR9. These results indicate that the combination of DOCK2 and DOCK180 plays a significant but not essential role in prevascular fetal thymus colonization.     

B-Cell Lymphoma in a Patient with Complete Interferon Gamma Receptor 1 Deficiency

Immunosuppression-associated lymphoproliferative disorders can be related to primary as well as acquired immune disorders. Interferon gamma receptor (IFN-γR) deficiency is a rare primary immune disorder, characterized by increased susceptibility to mycobacterial infections. Here we report the first case of an Epstein Barr Virus (EBV) related B-cell lymphoma in a patient with complete IFN-γR1 deficiency. The patient was a 20-year-old man with homozygous 22Cdel in IFNGR1 resulting in complete absence of IFN-γR1 surface expression and complete lack of responsiveness to IFN-γ in vitro. He had disseminated refractory Mycobacterium avium complex and Mycobacterium abscessus infections. At age 18 he presented with new spiking fever and weight loss that was due to an EBV-positive B-cell non-Hodgkin lymphoma. Two years later he died of progressive lymphoma. IFN-γ plays an important role in tumor protection and rejection. Patients with IFN-γR deficiencies and other immune deficits predisposing to mycobacterial disease seem to have an increased risk of malignancies, especially those related to viral infections. As more of these patients survive their early infections, cancer awareness and tumor surveillance may need to become a more routine part of management.     

Novel SMARCAL1 Bi-allelic Mutations Associated with a Chromosomal Breakage Phenotype in a Severe SIOD Patient

Purpose

Chromosomal instability syndromes include a group of rare diseases characterized by defective DNA-damage-response and increased risk of chromosomal breakage. Patients display defects in the recognition and/or repair of DNA damage, with a subsequent high rate of malignancies and abnormal gene rearrangements. Other clinical manifestations, such as immunodeficiency, neurodevelopmental delay and skeletal abnormalities, are present in some of these syndromes. We studied a patient with profound T-lymphocyte defect, neurodevelopmental delay, facial dysmorphism, nephrotic syndrome and spondyloepiphyseal bone dysplasia typical of SIOD.

Methods

Karyotype and chromosome fragility assays on patients’ peripheral blood mononuclear cells showed an abnormal rate of spontaneous breaks. Cell cycle analysis of patient’s fibroblasts following replication stress induced by hydroxyhurea revealed a delay in their release from S-phase to G2. When using higher concentrations of hydroxyhurea no patient fibroblast colonies could survive, compared with control fibroblasts. Whole-exome sequencing revealed novel compound heterozygote mutations in SMARCAL1 gene, resulting in putative frame shifts of encoded SMARCAL1 from each allele and no detected protein in patient’s cells. The patient’s youngest brother was found to have similar manifestations of SIOD but of less severity, including short stature, facial dysmorphism and typical osseous dysplasia, but no clinical findings suggestive of immunodeficiency and no chromosomal fragility. Similar to his sister, the brother carries both bi-allelic mutations in SMARCAL1 gene.

Conclusions

We present here the first evidence of intrinsic chromosomal instability in a severe SMARCAL1-deficient patient with a clinical picture of SIOD. Our results are consistent with the recently outlined role of SMARCAL1 protein in DNA damage response.     

Challenges in Hip Joint Modeling for a Patient with Proximal Femoral Focal Deficiency

We were presented with a technical challenge driven by a clinical need. A patient with proximal femoral focal deficiency required gait analysis, but our typical biomechanical model [Vicon Clinical Manager (VCM)] would not have correctly identified his abnormal right hip center (RHIP). His underdeveloped right femur was fused to his ileum, his anatomical knee functioned as his right hip, and an above-knee prosthesis provided functional knee and ankle joints. During a special calibration, we estimated the global location of RHIP as the center of the femoral epicondyles, also identifying the global location of pelvic markers. These data were used in equations after Davis et al.⁴ to establish local coordinates for RHIP. We used a system of three simultaneous equations to solve for input to VCM that would reproduce this location for RHIP. This procedure allowed for inverse dynamics in VCM, and showed the emergence of an abduction moment at the right hip postoperatively, that exceeded changes predicted by sensitivity analyses. Although our clinical need was met, we concluded that a better approach would have involved full implementation of custom models to reflect abnormal patient anatomy. © 2003 Biomedical Engineering Society. PAC2003: 8719St, 8710+e     

Successful interferon-alpha 2b therapy for unremitting warts in a patient with DOCK8 deficiency

The autosomal recessive form of the Hyper IgE syndrome (AR-HIES) with dedicator of cytokinesis 8 (DOCK8) deficiency is associated with difficult to treat persistent viral skin infections, including papilloma virus infection. Type I interferons play an important role in the defense against viruses. We examined the effect of therapy with IFN-α 2b in an 11-year old boy with DOCK8 deficiency due to a homozygous splice donor site mutation in DOCK8 intron 40. His unremitting warts showed dramatic response to IFN-α 2b therapy. Immunological studies revealed decreased circulating plasmacytoid dendritic cells (pDCs) and profound deficiency of IFN-α production by his peripheral blood mononuclear cells in response to treatment with CpG oligonucleotides. These findings indicate that underlying pDC deficiency and impaired IFN-α production may predispose to chronic viral infections in DOCK8 deficiency. IFN-α 2b therapy maybe useful in controlling recalcitrant viral infections in these patients.     

Mutations in PIK3CD Can Cause Hyper IgM Syndrome (HIGM) Associated with Increased Cancer Susceptibility

Autosomal dominant gain of function mutations in the gene encoding PI3K p110δ were recently associated with a novel combined immune deficiency characterized by recurrent sinopulmonary infections, CD4 lymphopenia, reduced class-switched memory B cells, lymphadenopathy, CMV and/or EBV viremia and EBV-related lymphoma. A subset of affected patients also had elevated serum IgM. Here we describe three patients in two families who were diagnosed with HIGM at a young age and were recently found to carry heterozygous mutations in PIK3CD. These patients had an abnormal circulating B cell distribution featuring a preponderance of early transitional (T1) B cells and plasmablasts. When stimulated in vitro, PIK3CD mutated B cells were able to secrete class-switched immunoglobulins. This finding implies that the patients’ elevated serum IgM levels were unlikely a product of an intrinsic B cell functional inability to class switch. All three patients developed malignant lymphoproliferative syndromes that were not associated with EBV. Thus, we identified a novel subset of patients with PIK3CD mutations associated with HIGM, despite indications of preserved in vitro B cell class switch recombination, as well as susceptibility to non-EBV-associated malignancies.     

Analysis of SWAP-70 as a Candidate Gene for Non-X-Linked Hyper IgM Syndrome and Common Variable Immunodeficiency

SWAP-70 is a recently identified protein that functions as the only B cell-specific component of an isotype switch recombination complex called SWAP. The SWAP complex has specificity for the switch regions upstream of the constant region immunoglobulin genes and it facilitates the transfer of DNA between switch regions. These features suggested that mutations in the gene encoding SWAP-70 might result in humoral immunodeficiency. To test this hypothesis we determined the genomic structure of this gene and used single-stranded conformational polymorphism (SSCP) analysis to screen DNA from 38 patients with either non-X-linked hyper IgM syndrome or common variable immunodeficiency. The results demonstrated that SWAP-70 consists of 12 exons spread over 89 kb at chromosome 11p15.2. SSCP analysis of the patient population revealed five polymorphic variants in the gene, one of which (Q505E) is an amino acid substitution in the putative nuclear export signal of SWAP-70. However, none of the alterations appeared to be associated with disease in the patients screened.     

Resolution of Multifocal Epstein-Barr Virus-Related Smooth Muscle Tumor in a Patient with GATA2 Deficiency Following Hematopoietic Stem Cell Transplantation

We performed allogeneic hematopoietic stem cell transplantation in a patient with GATA2 deficiency and an Epstein-Barr virus (EBV)-related spindle cell tumor involving the liver and possibly bone. He received a matched-related donor transplant with donor peripheral blood stem cells following a myeloablative conditioning regimen. He achieved rapid and high levels of donor engraftment and had complete reversal of the clinical and immunologic phenotype of MonoMAC/GATA2 deficiency and eradication of the EBV tumors after 3 years of follow-up. Thus, allogeneic hematopoietic stem cell transplant results in reconstitution of immunologic function and cure of EBV-associated malignancy in MonoMAC/GATA2 deficiency.     

Modulation of Lupus Phenotype by Adiponectin Deficiency in Autoimmune Mouse Models

Adiponectin is an adipocyte-derived cytokine with anti-inflammatory properties. Paradoxically, circulating adiponectin levels are increased in a number of inflammatory diseases. Thus, we sought to define the role of adiponectin deficiency in mouse models of autoimmunity. Adiponectin-deficient mice on a C57BL/6 background do not develop an autoimmune phenotype. Autoimmunity was also not observed in adiponectin-deficient mice generated on the permissive MRL background. However, adiponectin deficiency exacerbated the autoimmune phenotype of MRL-lpr mice. Compared with MRL-lpr mice, MRL-lpr.apn^−/− mice displayed greater lymphadenopathy and splenomegaly, as well as increased anti-nuclear antibody and anti-dsDNA production. In addition, evaluation of the kidney revealed larger glomerular tuft size, crescent formation, increased IgG and C3 deposits, and mesangial expansion in the MRL-lpr.apn^−/− mice. The effects of adiponectin deficiency on the autoimmune phenotypes were more pronounced in female versus male mice. These data show that, while adiponectin deficiency is not sufficient to confer autoimmunity, adiponectin acts as a negative modulator of the autoimmune phenotype in a murine model of lupus.