Overview of 15-year severe combined immunodeficiency in the Netherlands: towards newborn blood spot screening

Severe combined immune deficiency (SCID) is a fatal primary immunodeficiency usually presenting in the first months of life with (opportunistic) infections, diarrhea, and failure to thrive. Hematopoietic stem cell transplantation (HSCT) and gene therapy (GT) are curative treatment options. The objective of the study was to assess the morbidity, mortality, and diagnostic and therapeutic delay in children with SCID in the Netherlands in the last 15 years. These data may help to judge whether SCID should be considered to be included in our national neonatal screening program. In the period 1998–2013, 43 SCID patients were diagnosed in the Netherlands, 11 of whom were atypical SCID (presentation beyond the first year). The median interval between the first symptom and diagnosis was 2 months (range 0–1173 months). The total mortality was 42 %. In total, 32 patients were treated with HSCT of whom 8 were deceased. Nine patients died due to severe infectious complications before curative treatment could be initiated. Conclusion: Because of a high mortality of patients with SCID before HSCT could be initiated, only a national newborn screening program and pre-emptive HSCT or GT will be able to improve survival of these patients

Exhaustion of the CD8+ T cell compartment in patients with mutations in phosphoinositide 3-kinase delta

Pathogenic gain-of-function mutations in the gene encoding phosphoinositide 3-kinase delta (PI3Kδ) cause activated PI3Kδ syndrome (APDS), a disease characterized by humoral immunodeficiency, lymphadenopathy, and an inability to control persistent viral infections including Epstein-Barr virus (EBV) and cytomegalovirus (CMV) infections. Understanding the mechanisms leading to impaired immune response is important to optimally treat APDS patients. Immunosenescence of CD8+ T cells was suggested to contribute to APDS pathogenesis. However, the constitutive activation of T cells in APDS may also result in T cell exhaustion. Therefore, we studied exhaustion of the CD8+ T cell compartment in APDS patients and compared them with healthy controls and HIV patients, as a control for exhaustion. The subset distribution of the T cell compartment of APDS patients was comparable with HIV patien

What Works When Treating Granulomatous Disease in Genetically Undefined CVID? A Systematic Review

Background: Granulomatous disease is reported in at least 8–20% of patients with common variable immunodeficiency (CVID). Granulomatous disease mainly affects the lungs, and is associated with significantly higher morbidity and mortality. In half of patients with granulomatous disease, extrapulmonary manifestations are found, affecting e.g. skin, liver, and lymph nodes. In literature various therapies have been reported, with varying effects on remission of granulomas and related clinical symptoms. However, consensus recommendations for optimal management of extrapulmonary granulomatous disease are lacking. Objective: To present a literature overview of the efficacy of currently described therapies for extrapulmonary granulomatous disease in CVID (CVID+EGD), compared to known treatment regimens for pulmonary granulomatous disease in CVID (CVID+PGD). Methods: The following databases were searched: Embase, Medline (Ovid), Web-of-Science Core Collection, Cochrane Central, and Google Scholar. Inclusion criteria were 1) CVID patients with granulomatous disease, 2) treatment for granulomatous disease reported, and 3) outcome of treatment reported. Patient characteristics, localization of granuloma, treatment, and association with remission of granulomatous disease were extracted from articles. Results: We identified 64 articles presenting 95 CVID patients with granulomatous disease, wherein 117 different treatment courses were described. Steroid monotherapy was most frequently described in CVID+EGD (21 out of 53 treatment courses) and resulted in remission in 85.7% of cases. In CVID+PGD steroid monotherapy was described in 15 out of 64 treatment courses, and was associated with remission in 66.7% of cases. Infliximab was reported in CVID+EGD in six out of 53 treatment courses and was mostly used in granulomatous disease affecting the skin (four out of six cases). All patients (n = 9) treated with anti-TNF-α therapies (infliximab and etanercept) showed remission of extrapulmonary granulomatous disease. Rituximab with or without azathioprine was rarely used for CVID+EGD, but frequently used in CVID+PGD where it was associated with remission of granulomatous disease in 94.4% (17 of 18 treatment courses). Conclusion: Although the number of CVID+EGD patients was limited, data indicate that steroid monotherapy often results in remission, and that anti-TNF-α treatment is effective for granulomatous disease affecting the skin. Also, rituximab with or without azathioprine was mainly described in CVID+PGD, and only in few cases of CVID+EGD

Proline-serine-threonine phosphatase interacting protein 1 (PSTPIP1) controls immune synapse stability in human T cells

Background: Proline-serine-threonine phosphatase interacting protein 1 (PSTPIP1) is a cytosolic adaptor protein involved with T-cell activation, differentiation, and migration. On cognate T-cell contact, PSTPIP1 is recruited to surface-expressed CD2, where it regulates F-actin remodeling. An immune synapse (IS) is thereby rapidly formed, consisting of T-cell receptor clusters surrounded by a ring of adhesion molecules, including CD2. Objective: From genetic screening of patients with primary immunodeficiencies, we identified 2 mutations in PSTPIP1, R228C and T274M, which we further characterized in the primary patients’ T cells. Methods: F-actin dynamics were assessed in primary T cells from the patients and control subjects by using fluorescence-activated cell sorting. HEK293T and Jurkat cells were transfected with R228C, T274M, and wild-type PSTPIP1 to visualize F-actin in IS formation. CD2-PSTPIP1 association was quantified through immunoprecipitation assays. Results: The patients presented with immunodeficiency without signs of autoinflammation. The patient with the R228C mutation had expansion of mostly naive phenotype T cells and few memory T cells; the patient with the T274M mutation had 75% reduction in CD4 T cells that were predominantly of the memory subset. We observed F-actin polymerization defects in T cells from both patients with PSTPIP1, most notably the patient with the T274M mutation. Capping of CD2-containing membrane microdomains was disrupted. Analysis of IS formation using Jurkat T-cell transfectants revealed a reduction in F-actin accumulation at the IS, again especially in cells from the patient with the T274M PSTPIP1 mutation. T cells from the patient with the T274M mutation migrated spontaneously at increased speed, as assessed in a 3-dimensional collagen matrix, whereas T-cell receptor cross-linking induced a significantly diminished calcium flux. Conclusions: We propose that PSTPIP1 T-cell differentiation defects are caused by defective control of F-actin polymerization. A preactivated polymerized F-actin status, as seen in T cells from patients with the PSTPIP1 T274M mutation, appears particularly damaging. PSTPIP1 controls IS formation and cell adhesion through its function as an orchestrator of the F-actin cytoskeleton

Proline-serine-threonine phosphatase interacting protein 1 (PSTPIP1) controls immune synapse stability in human T cells

Background: Proline-serine-threonine phosphatase interacting protein 1 (PSTPIP1) is a cytosolic adaptor protein involved with T-cell activation, differentiation, and migration. On cognate T-cell contact, PSTPIP1 is recruited to surface-expressed CD2, where it regulates F-actin remodeling. An immune synapse (IS) is thereby rapidly formed, consisting of T-cell receptor clusters surrounded by a ring of adhesion molecules, including CD2. Objective: From genetic screening of patients with primary immunodeficiencies, we identified 2 mutations in PSTPIP1, R228C and T274M, which we further characterized in the primary patients’ T cells. Methods: F-actin dynamics were assessed in primary T cells from the patients and control subjects by using fluorescence-activated cell sorting. HEK293T and Jurkat cells were transfected with R228C, T274M, and wild-type PSTPIP1 to visualize F-actin in IS formation. CD2-PSTPIP1 association was quantified through immunoprecipitation assays. Results: The patients presented with immunodeficiency without signs of autoinflammation. The patient with the R228C mutation had expansion of mostly naive phenotype T cells and few memory T cells; the patient with the T274M mutation had 75% reduction in CD4 T cells that were predominantly of the memory subset. We observed F-actin polymerization defects in T cells from both patients with PSTPIP1, most notably the patient with the T274M mutation. Capping of CD2-containing membrane microdomains was disrupted. Analysis of IS formation using Jurkat T-cell transfectants revealed a reduction in F-actin accumulation at the IS, again especially in cells from the patient with the T274M PSTPIP1 mutation. T cells from the patient with the T274M mutation migrated spontaneously at increased speed, as assessed in a 3-dimensional collagen matrix, whereas T-cell receptor cross-linking induced a significantly diminished calcium flux. Conclusions: We propose that PSTPIP1 T-cell differentiation defects are caused by defective control of F-actin polymerization. A preactivated polymerized F-actin status, as seen in T cells from patients with the PSTPIP1 T274M mutation, appears particularly damaging. PSTPIP1 controls IS formation and cell adhesion through its function as an orchestrator of the F-actin cytoskeleton

Low IgA Associated With Oropharyngeal Microbiota Changes and Lung Disease in Primary Antibody Deficiency

Common Variable Immunodeficiency (CVID) and X-linked agammaglobulinemia (XLA) are primary antibody deficiencies characterized by hypogammaglobulinemia and recurrent infections, which can lead to structural airway disease (AD) and interstitial lung disease (ILD). We investigated associations between serum IgA, oropharyngeal microbiota composition and severity of lung disease in these patients. In this cross-sectional multicentre study we analyzed oropharyngeal microbiota composition of 86 CVID patients, 12 XLA patients and 49 healthy controls (HC) using next-generation sequencing of the 16S rRNA gene. qPCR was used to estimate bacterial load. IgA was measured in serum. High resolution CT scans were scored for severity of AD and ILD. Oropharyngeal bacterial load was increased in CVID patients with low IgA (p = 0.013) and XLA (p = 0.029) compared to HC. IgA status was associated with distinct beta (between-sample) diversity (p = 0.039), enrichment of (Allo)prevotella, and more severe radiographic lung disease (p = 0.003), independently of recent antibiotic use. AD scores were positively associated with Prevotella, Alloprevotella, and Selenomonas, and ILD scores with Streptococcus and negatively with Rothia. In clinically stable patients with CVID and XLA, radiographic lung disease was associated with IgA deficiency and expansion of distinct oropharyngeal bacterial taxa. Our findings highlight IgA as a potential driver of upper respiratory tract microbiota homeostasis

B-cell development and functions and therapeutic options in adenosine deaminase-deficient patients

Background Adenosine deaminase (ADA) deficiency causes severe cellular and humoral immune defects and dysregulation because of metabolic toxicity. Alterations in B-cell development and function have been poorly studied. Enzyme replacement therapy (ERT) and hematopoietic stem cell (HSC) gene therapy (GT) are therapeutic options for patients lacking a suitable bone marrow (BM) transplant donor. Objective We sought to study alterations in B-cell development in ADA-deficient patients and investigate the ability of ERT and HSC-GT to restore normal B-cell differentiation and function. Methods Flow cytometry was used to characterize B-cell development in BM and the periphery. The percentage of gene-corrected B cells was measured by using quantitative PCR. B cells were assessed for their capacity to proliferate and release IgM after stimulation. Results Despite the severe peripheral B-cell lymphopenia, patients with ADA-deficient severe combined immunodeficiency showed a partial block in central BM development. Treatment with ERT or HSC-GT reverted most BM alterations, but ERT led to immature B-cell expansion. In the periphery transitional B cells accumulated under ERT, and the defect in maturation persisted long-term. HSC-GT led to a progressive improvement in B-cell numbers and development, along with increased levels of gene correction. The strongest selective advantage for ADA-transduced cells occurred at the transition from immature to naive cells. B-cell proliferative responses and differentiation to immunoglobulin secreting IgM after B-cell receptor and Toll-like receptor triggering were severely impaired after ERT and improved significantly after HSC-GT. Conclusions ADA-deficient patients show specific defects in B-cell development and functions that are differently corrected after ERT and HSC-GT

B-cell development and functions and therapeutic options in adenosine deaminase–deficient patients

BACKGROUND: Adenosine deaminase (ADA) deficiency causes severe cellular and humoral immune defects and dysregulation because of metabolic toxicity. Alterations in B-cell development and function have been poorly studied. Enzyme replacement therapy (ERT) and hematopoietic stem cell (HSC) gene therapy (GT) are therapeutic options for patients lacking a suitable bone marrow (BM) transplant donor. OBJECTIVE: We sought to study alterations in B-cell development in ADA-deficient patients and investigate the ability of ERT and HSC-GT to restore normal B-cell differentiation and function. METHODS: Flow cytometry was used to characterize B-cell development in BM and the periphery. The percentage of gene-corrected B cells was measured by using quantitative PCR. B cells were assessed for their capacity to proliferate and release IgM after stimulation. RESULTS: Despite the severe peripheral B-cell lymphopenia, patients with ADA-deficient severe combined immunodeficiency showed a partial block in central BM development. Treatment with ERT or HSC-GT reverted most BM alterations, but ERT led to immature B-cell expansion. In the periphery transitional B cells accumulated under ERT, and the defect in maturation persisted long-term. HSC-GT led to a progressive improvement in B-cell numbers and development, along with increased levels of gene correction. The strongest selective advantage for ADA-transduced cells occurred at the transition from immature to naive cells. B-cell proliferative responses and differentiation to immunoglobulin secreting IgM after B-cell receptor and Toll-like receptor triggering were severely impaired after ERT and improved significantly after HSC-GT. CONCLUSIONS: ADA-deficient patients show specific defects in B-cell development and functions that are differently corrected after ERT and HSC-GT