Clinical and Treatment History of Patients with Partial DiGeorge Syndrome and Autoimmune Cytopenia at Multiple Centers.

BACKGROUND: Patients with partial DiGeorge syndrome (pDGS) can present with immune dysregulation, the most common being autoimmune cytopenia (AIC). There is a lack of consensus on the approach to type, combination, and timing of therapies for AIC in pDGS. Recognition of immune dysregulation early in pDGS clinical course may help individualize treatment and prevent adverse outcomes from chronic immune dysregulation. OBJECTIVES: Objectives of this study were to characterize the natural history, immune phenotype, and biomarkers in pDGS with AIC. METHODS: Data on clinical presentation, disease severity, immunological phenotype, treatment selection, and response for patients with pDGS with AIC were collected via retrospective chart review. Flow cytometric analysis was done to assess T and B cell subsets, including biomarkers of immune dysregulation. RESULTS: Twenty-nine patients with the diagnosis of pDGS and AIC were identified from 5 international institutions. Nineteen (62%) patients developed Evan's syndrome (ES) during their clinical course and twenty (69%) had antibody deficiency syndrome. These patients demonstrated expansion in T follicular helper cells, CD19hiCD21lo B cells, and double negative cells and reduction in CD4 naïve T cells and regulatory T cells. First-line treatment for 17/29 (59%) included corticosteroids and/or high-dose immunoglobulin replacement therapy. Other overlapping therapies included eltrombopag, rituximab, and T cell immunomodulators. CONCLUSIONS: AIC in pDGS is often refractory to conventional AIC treatment paradigms. Biomarkers may have utility for correlation with disease state and potentially even response to therapy. Immunomodulating therapies could be initiated early based on early immune phenotyping and biomarkers before the disease develops or significantly worsens.

Detrimental NFKB1 missense variants affecting the Rel-homology domain of p105/p50.

Most of the currently known heterozygous pathogenic NFKB1 (Nuclear factor kappa B subunit 1) variants comprise deleterious defects such as severe truncations, internal deletions, and frameshift variants. Collectively, these represent the most frequent monogenic cause of common variable immunodeficiency (CVID) identified so far. NFKB1 encodes the transcription factor precursor p105 which undergoes limited proteasomal processing of its C-terminal half to generate the mature NF-κB subunit p50. Whereas p105/p50 haploinsufficiency due to devastating genetic damages and protein loss is a well-known disease mechanism, the pathogenic significance of numerous NFKB1 missense variants still remains uncertain and/or unexplored, due to the unavailability of accurate test procedures to confirm causality. In this study we functionally characterized 47 distinct missense variants residing within the N-terminal domains, thus affecting both proteins, the p105 precursor and the processed p50. Following transient overexpression of EGFP-fused mutant p105 and p50 in HEK293T cells, we used fluorescence microscopy, Western blotting, electrophoretic mobility shift assays (EMSA), and reporter assays to analyze their effects on subcellular localization, protein stability and precursor processing, DNA binding, and on the RelA-dependent target promoter activation, respectively. We found nine missense variants to cause harmful damage with intensified protein decay, while two variants left protein stability unaffected but caused a loss of the DNA-binding activity. Seven of the analyzed single amino acid changes caused ambiguous protein defects and four variants were associated with only minor adverse effects. For 25 variants, test results were indistinguishable from those of the wildtype controls, hence, their pathogenic impact remained elusive. In summary, we show that pathogenic missense variants affecting the Rel-homology domain may cause protein-decaying defects, thus resembling the disease-mechanisms of p105/p50 haploinsufficiency or may cause DNA-binding deficiency. However, rare variants (with a population frequency of less than 0.01%) with minor abnormalities or with neutral tests should still be considered as potentially pathogenic, until suitable tests have approved them being benign.

Matrix Metalloproteinase 7 Expression and Apical Epithelial Defects in Atp8b1 Mutant Mouse Model of Pulmonary Fibrosis.

Abnormalities in airway epithelia and lung parenchyma are found in Atp8b1 mutant mice, which develop pulmonary fibrosis after hyperoxic insult. Microarray and ingenuity pathway analysis (IPA) show numerous transcripts involved in ciliogenesis are downregulated in 14-month (14 M) -old Atp8b1 mouse lung compared with wild-type C57BL/6. Lung epithelium of Atp8b1 mice demonstrate apical abnormalities of ciliated and club cells in the bronchial epithelium on transmission electron microscopy (TEM). Matrix metalloproteinase 7 (MMP7) regulates of ciliogenesis and is a biomarker for idiopathic pulmonary fibrosis (IPF) in humans. Mmp7 transcript and protein expression are significantly upregulated in 14 M Atp8b1 mutant mouse lung. MMP7 expression is also increased in bronchoalveolar lavage fluid (BAL). Immunohistochemistry is localized MMP7 to bronchial epithelial cells in the Atp8b1 mutant. In conclusion, MMP7 is upregulated in the aged Atp8b1 mouse model, which displays abnormal ciliated cell and club cell morphology. This mouse model can facilitate the exploration of the role of MMP7 in epithelial integrity and ciliogenesis in IPF. The Atp8b1 mutant mouse is proposed as a model for IPF.

Anaphylaxis: Access to Epinephrine in Outpatient Setting.

Epinephrine is a lifesaving medication to treat systemic allergic reactions including anaphylaxis. Epinephrine autoinjectors (EAIs) are expensive, not available everywhere in the world, and shortages can limit their access. Epinephrine prefilled syringes and epinephrine kits are lower-cost alternatives to EAIs. Advantages, disadvantages, and costs of available products are discussed and the socioeconomic factors impacting access to EAIs described. EAIs designed for infants also are discussed.

Primary Immunodeficiency in Children With Autoimmune Cytopenias: Retrospective 154-Patient Cohort.

Background: Primary immunodeficiency is common among patients with autoimmune cytopenia. Objective: The purpose of this study is to retrospectively identify key clinical features and biomarkers of primary immunodeficiency (PID) in pediatric patients with autoimmune cytopenias (AIC) so as to facilitate early diagnosis and targeted therapy. Methods: Electronic medical records at a pediatric tertiary care center were reviewed. We selected 154 patients with both AIC and PID (n=17), or AIC alone (n=137) for inclusion in two cohorts. Immunoglobulin levels, vaccine titers, lymphocyte subsets (T, B and NK cells), autoantibodies, clinical characteristics, and response to treatment were recorded. Results: Clinical features associated with AIC-PID included splenomegaly, short stature, and recurrent or chronic infections. PID patients were more likely to have autoimmune hemolytic anemia (AIHA) or Evans syndrome than AIC-only patients. The AIC-PID group was also distinguished by low T cells (CD3 and CD8), low immunoglobulins (IgG and IgA), and higher prevalence of autoantibodies to red blood cells, platelets or neutrophils. AIC diagnosis preceded PID diagnosis by 3 years on average, except among those with partial DiGeorge syndrome. AIC-PID patients were more likely to fail first-line treatment. Conclusions: AIC patients, especially those with Evans syndrome or AIHA, should be evaluated for PID. Lymphocyte subsets and immune globulins serve as a rapid screen for underlying PID. Early detection of patients with comorbid PID and AIC may improve treatment outcomes. Prospective studies are needed to confirm the diagnostic clues identified and to guide targeted therapy.

Case Report: A Novel Pathogenic Missense Mutation in FAS: A Multi-Generational Case Series of Autoimmune Lymphoproliferative Syndrome.

Autoimmune Lymphoproliferative Syndrome (ALPS), commonly caused by mutations in the FAS gene, is a disease with variable penetrance. Subjects may be asymptomatic, or they may present with lymphadenopathy, splenomegaly, cytopenias, or malignancy. Prompt recognition of ALPS is needed for optimal management. We describe a multi-generational cohort presenting with clinical manifestations of ALPS, and a previously unreported heterozygous missense variant of uncertain significance in FAS (c.758G >T, p.G253V), located in exon 9. Knowledge of the underlying genetic defect permitted prompt targeted therapy to treat acute episodes of cytopenia. This cohort underscores the importance of genetic testing in subjects with clinical features of ALPS and should facilitate the reclassification of this variant as pathogenic.

Asymptomatic Infant With Atypical SCID and Novel Hypomorphic RAG Variant Identified by Newborn Screening: A Diagnostic and Treatment Dilemma.

The T-cell receptor excision circle (TREC) assay detects T-cell lymphopenia (TCL) in newborns and is especially important to identify severe combined immunodeficiency (SCID). A spectrum of SCID variants and non-SCID conditions that present with TCL are being discovered with increasing frequency by newborn screening (NBS). Recombination-activating gene (RAG) deficiency is one the most common causes of classical and atypical SCID and other conditions with immune dysregulation. We present the case of an asymptomatic male with undetectable TRECs on NBS at 1 week of age. The asymptomatic newborn was found to have severe TCL, but normal B cell quantities and lymphocyte proliferation upon mitogen stimulation. Next generation sequencing revealed compound heterozygous hypomorphic RAG variants, one of which was novel. The moderately decreased recombinase activity of the RAG variants (16 and 40%) resulted in abnormal T and B-cell receptor repertoires, decreased fraction of CD3+ TCRVα7.2+ T cells and an immune phenotype consistent with the RAG hypomorphic variants. The patient underwent successful treatment with hematopoietic stem cell transplantation (HSCT) at 5 months of age. This case illustrates how after identification of a novel RAG variant, in vitro studies are important to confirm the pathogenicity of the variant. This confirmation allows the clinician to expedite definitive treatment with HSCT in an asymptomatic phase, mitigating the risk of serious infectious and non-infectious complications.

Economic considerations in the treatment of systemic allergic reactions.

Epinephrine is a life-saving medication used to treat systemic allergic reactions including anaphylaxis. Epinephrine autoinjectors (EAIs) are expensive and worldwide availability is limited. Epinephrine prefilled syringes and epinephrine kits are potentially lower-cost alternatives to EAIs. Advantages, disadvantages, and costs of available products are discussed. The socioeconomic factors impacting access to EAIs are described.

Cardiovascular and Diabetic Medications That Cause Bradykinin-Mediated Angioedema.

Medication-induced angioedema is a bradykinin-mediated process that results from increased production or decreased degradation of bradykinin. These reactions are documented for several cardiac medications including blockers of the renin-angiotensin-aldosterone system (RAAS). Other cardiovascular and diabetes medications further increase the risk of medication-induced angioedema, particularly with concomitant use of RAAS inhibitors. Dipeptidyl peptidase IV inhibitors are a class of oral diabetic agents that affect bradykinin and substance P degradation and therefore can lead to angioedema. Neprilysin inhibitors are a separate class of cardiac medications, which includes sacubitril, and can lead to drug-induced angioedema especially when used in combination with RAAS inhibitors. This article discusses the proposed mechanisms by which these medications cause angioedema and how medication-induced angioedema differs from mast cell-mediated angioedema. It also details how to recognize medication-induced angioedema and the treatment options available.

Specific immunoglobulin E and immunoglobulin G4 toward major allergens of house-dust mite during allergen-specific immunotherapy.

BACKGROUND: Specific immunoglobulin E (sIgE) and sIgG4 to house-dust mite (HDM) major allergens during allergen immunotherapy (AIT) and their clinical relevance remain unclear. OBJECTIVE: To investigate the variation of sIgE and sIgG4 to HDM major allergens and the correlation with clinical responses during AIT in patients with allergic rhinitis. METHODS: Thirty-nine patients with HDM allergy were divided into the AIT group (taking immunotherapy) and the control group (medication only use). The AIT group was subdivided into negative clinical responses to AIT (nAIT) group and positive clinical responses to AIT (pAIT) group according to symptom relief and subjective evaluation. sIgE and sIgG4 to Dermatophagoides pteronyssinus (Dp) and Dermatophagoides farinae (Df), and their group 1 and group 2 major allergens (Dp1, Df1, Dp2, and Df2) were measured before AIT, at 6 months, and at 1 year after starting AIT. RESULTS: Dp2, Df, and Df2 sIgE values decreased significantly in the pAIT group versus the nAIT group after 1 year of AIT (median values of delta change were Dp2, -10.09 versus 5.89 kU/L, p = 0.001; median values of Df were -9.69 versus 17.54 kU/L, p = 0.004; median values of Df2 were -11.06 versus 20.08 kU/L, p = 0.013). There was a robust increase in the sIgG4 values to Dp, Df, and their major allergens in both the pAIT and the nAIT groups overall after 1 year of treatment. CONCLUSION: Patients with a positive response to AIT showed a significant reduction of HDM group 2 sIgEs compared with those with a negative response to AIT, which indicated that a decrease in group 2 sIgEs could be a marker that reflected AIT clinical efficacy.

The High Cost of Epinephrine Autoinjectors and Possible Alternatives.

Epinephrine autoinjectors provide potentially life-saving therapy for pediatric and adult subjects with systemic allergic reactions, including anaphylaxis. However, the cost of these devices, specifically the EpiPen (Mylan, Canonsburg, Pa), is increasing exponentially. Epinephrine autoinjectors are commonly prescribed in the United States but are not readily available worldwide. Alternatives for the self-administration of epinephrine exist and should be considered for patients who cannot afford or do not have access to these devices. The epinephrine prefilled syringe, stored in an eyeglass or pencil case, is a safe and viable option for the self-administration of epinephrine. Epinephrine prefilled syringes may not be as ideal as using autoinjectors but are superior to patients living without access to this medication.

Global gene profiling of aging lungs in Atp8b1 mutant mice.

OBJECTIVE: Recent studies implicate cardiolipin oxidation in several age-related diseases. Atp8b1 encoding Type 4 P-type ATPases is a cardiolipin transporter. Mutation in Atp8b1 gene or inflammation of the lungs impairs the capacity of Atp8b1 to clear cardiolipin from lung fluid. However, the link between Atp8b1 mutation and age-related gene alteration is unknown. Therefore, we investigated how Atp8b1 mutation alters age-related genes. METHODS: We performed Affymetrix gene profiling of lungs isolated from young (7-9 wks, n=6) and aged (14 months, 14 M, n=6) C57BL/6 and Atp8b1 mutant mice. In addition, Ingenuity Pathway Analysis (IPA) was performed. Differentially expressed genes were validated by quantitative real-time PCR (qRT-PCR). RESULTS: Global transcriptome analysis revealed 532 differentially expressed genes in Atp8b1 lungs, 157 differentially expressed genes in C57BL/6 lungs, and 37 overlapping genes. IPA of age-related genes in Atp8b1 lungs showed enrichment of Xenobiotic metabolism and Nrf2-mediated signaling pathways. The increase in Adamts2 and Mmp13 transcripts in aged Atp8b1 lungs was validated by qRT-PCR. Similarly, the decrease in Col1a1 and increase in Cxcr6 transcripts was confirmed in both Atp8b1 mutant and C57BL/6 lungs. CONCLUSION: Based on transcriptome profiling, our study indicates that Atp8b1 mutant mice may be susceptible to age-related lung diseases.

Debunking myths about "allergy" to radiocontrast media in an academic institution.

PURPOSE: Patients with "allergy" to iodine and shellfish often do not obtain necessary radiologic procedures due to anxiety about potential radiocontrast media reactions. This study assesses the impact of an educational intervention to dispel these myths. METHODS: The authors surveyed 252 internal medicine, emergency medicine, pediatrics, radiology, obstetrics/gynecology, and surgery health professionals before and after an educational intervention. Pre- and posttest responses were analyzed to assess the impact of the intervention on beliefs about radiocontrast media reactions and their perceived relationship to shellfish allergy and iodine "allergy." RESULTS: The mean pre- and posttest correct response scores were 41% and 91%, respectively. The intervention had a greater impact on respondents' knowledge about iodine allergy than shellfish allergy, most likely due to the difference in baseline knowledge (P < 0.005). Emergency medicine garnered the highest pretest correct response score (54%). Internal medicine earned the lowest pretest score (30%). There was a significant difference between the highest and lowest scoring specialties on the pretest (P = 0.037). There was no statistically significant correlation with training levels. There was a considerable decrease in the percentage of respondents who would withhold radiologic studies from patients suspected of shellfish or iodine allergy. The percentage of respondents who would premedicate patients with antihistamines or steroids also decreased significantly. CONCLUSION: An educational intervention helps rectify misconceptions among health care professionals about radiocontrast media reactions and their perceived relationship to shellfish or iodine allergy.

Evidence-based practice center network and health technology assessment in the United States: bridging the cultural gap.

OBJECTIVES: The purpose of this study was to identify the Evidence-Based Practice Center (EPC) network participants' perceptions of the characteristics of the EPC process and the relationship of the process to the success of EPC reports. METHODS: Semistructured interviews were conducted with the three groups involved in the EPC: EPC staff, Agency for Healthcare Research and Quality (AHRQ) staff, and representatives of partner organizations. RESULTS: The analysis of the coded transcripts revealed three related major themes, which form the conceptual basis for the interpretation presented here: the definition of a successful report, the determinants of a successful report, and the role of AHRQ in the process. CONCLUSIONS: A successful report is a report that is used. The ultimate success of the core health technology assessment objective, moving from research to policy, depends on balancing two values: excellence and relevance. Our findings are consistent with the "two communities thesis," which postulates the existence of two camps that confer different values to excellence and relevance, with resulting tension. A promising model for approaching this tension is integration or collaboration, which requires linking researchers and policy makers, promoting productive dialogues about the formulation and timing of analysis, and early consideration of how the resulting analysis will be used. This effort suggests that actively blurring the frontiers between these two groups will enhance their interaction. Furthermore, enhancing the role of the AHRQ as scientific broker will maximize the potential of the EPC network.

Dissemination of Evidence-based Practice Center reports.

The Evidence-based Practice Center (EPC) program within the Agency for Healthcare Research and Quality (AHRQ) provides detailed evidence reports for partner organizations that they can translate into activities that improve patient care. A review of these dissemination activities provides a rich opportunity to understand how to create more successful linkages between best evidence and best practice. On the basis of interviews with EPC directors, AHRQ staff, and representatives of public and private users of EPC reports, we summarize the variety of efforts to disseminate the work of the EPCs. We also identify a case example of a successful dissemination of an EPC report. Experience to date reinforces the importance of creating close ties between researchers and the policymakers, clinicians, and other decision makers who use EPC evidence reports; developing a conceptual framework to guide the process; and establishing the resource foundation for the entire effort.