Publications by authors named "Alexandra F Freeman"

B-1 cells are innate-like immune cells abundant in serosal cavities with antibodies enriched in bacterial recognition, yet their existence in humans has been controversial. The CD5 B-1a subset expresses anti-inflammatory molecules including IL-10, PDL1 and CTLA4 and can be immunoregulatory. Unlike conventional B cells that are continuously replenished, B-1a cells are produced early in life and maintained through self-renewal.

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Background: Hematopoietic cell transplantation (HCT) provides effective long-term management for some inborn errors of immunity. Genetic findings can inform donor selection, considerations in conditioning intensity and agents, and graft-versus-host disease prophylaxis. Exome/genome sequencing is increasingly accessible but of uncertain clinical utility.

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The human skin microbiome is intricately intertwined with host immunity. While studies have elucidated microbial influences on immunity, understanding how immune alterations modulate this equilibrium remains limited. We investigated the dual impact of immune deficiency and hematopoietic stem cell transplantation (HSCT) on the skin microbiome in 24 patients with dedicator of cytokinesis 8 (DOCK8) deficiency, a rare inborn error of immunity.

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Signal transduction and activator of transcription 3 hyperimmunoglobulin E syndrome (STAT3-HIES) is a multisystem disorder causing recurrent skin and respiratory infection with bronchiectasis, pneumatoceles, and aspergillosis; lymphoma; and extraimmune manifestations including fractures and vasculopathy. Published data on immune and extraimmune hematopoietic stem cell transplant (HSCT) outcomes focus on case reports or small cohorts. We conducted an international multicenter retrospective study of HSCT in STAT3-HIES.

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Defects in lipid metabolism have been associated with inflammatory skin diseases such as atopic dermatitis (AD). The goal of this study was to characterize the biosynthetic pathways activated during epidermal repair using MALDI imaging mass spectrometry (IMS). Keratinocyte models confirmed the importance of glycerophospholipids, glycosphingolipids, and sialic acid in wound closure.

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Refractory disseminated coccidioidomycosis (DCM) is a severe disease with limited treatment options. This report reviews our own and prior published experiences using adjunctive interferon-γ therapy in refractory DCM, showing overall favorable responses in patients without Signal Transducer and Activator of Transcription 1 gain-of-function mutations.

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Rationale: Hyper IgE syndrome (STAT3-HIES), also known as Job's syndrome, is a rare immunodeficiency disease typically caused by dominant-negative STAT3 mutations. STAT3-HIES is characterized by chronic pulmonary infection and inflammation, suggesting impaired innate host defense.

Objectives: To identify airway epithelial host defense defects caused by STAT3 mutations that, together with immune dysfunction, contribute to recurrent pulmonary infections in STAT3-HIES.

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Partial RAG deficiency (pRD) can manifest with systemic and tissue-specific immune dysregulation, with inflammatory bowel disease (IBD) in 15% of the patients. We aimed at identifying the immunopathological and microbial signatures associated with IBD in patients with pRD and in a mouse model of pRD (Rag1w/w) with spontaneous development of colitis. pRD patients with IBD and Rag1w/w mice showed a systemic and colonic Th1/Th17 inflammatory signature.

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Allergic fungal rhinosinusitis (AFRS) is a unique endotype of chronic rhinosinusitis with nasal polyps (CRSwNP). Despite high recurrence rates and often more severe presenting signs compared with other subtypes of CRSwNP, research dedicated to AFRS has been lacking. Diagnostic criteria are outdated, the mechanistic relationship of AFRS to other associated diseases is unclear, and the pathophysiology of disease and risk factors for recurrence have not been well studied.

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Reduced susceptibility to antifungals is common among members of genera and , with optimal treatments still not fully defined. antifungal susceptibility results and clinical data do not comprehensively account for the advent of new species identified by molecular phylogenetics. Using Clinical and Laboratory Standards Institute (CLSI) methodology, we tested a total of 103 clinical isolates obtained from patients at the NIH Clinical Center.

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Immune reconstitution inflammatory syndrome (IRIS) is a well-recognized complication in people with HIV (PWH) starting antiretroviral therapy (ART), but data on IRIS in hematopoietic cell transplantation (HCT) recipients are limited. To address this gap, we conducted a narrative review of the literature on IRIS in HCT recipients, including 21 studies encompassing 53 patients. The majority of reported patients had inborn errors of immunity (IEI) and developed IRIS associated with Bacillus Calmette-Guérin (BCG)-infection from prior vaccination ("BCG-IRIS").

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Human recombination-activating gene (RAG) deficiency can manifest with distinct clinical and immunological phenotypes. By applying a multiomics approach to a large group of -mutated patients, we aimed at characterizing the immunopathology associated with each phenotype. Although defective T and B cell development is common to all phenotypes, patients with hypomorphic variants can generate T and B cells with signatures of immune dysregulation and produce autoantibodies to a broad range of self-antigens, including type I interferons.

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Signal transduction downstream of activating stimuli controls CD8+ T cell biology, however these external inputs can become uncoupled from transcriptional regulation in Primary Immune Regulatory Disorders (PIRDs). Gain-of-function (GOF) variants in STAT3 amplify cytokine signaling and cause a severe PIRD characterized by early onset autoimmunity, lymphoproliferation, recurrent infections, and immune dysregulation. In both primary human and mouse models of STAT3 GOF, CD8+ T cells have been implicated as pathogenic drivers of autoimmunity.

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The Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway is highly conserved and essential for numerous biological functions triggered by extracellular signals, including cell proliferation, metabolism, immune response, and inflammation. Defects in STATs, either loss-of-function or gain-of-function defects, lead to a broad spectrum of clinical phenotypes in humans, including a wide range of infectious complications. The susceptibility to pathogens can stem from defects in immune cells within the hematopoietic compartment, impaired barrier functions of non-hematopoietic compartment, or a combination of both, depending on the specific STAT defect as well as the pathogen exposure history.

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Purpose Of Review: The identification of STAT1 gain-of-function (GOF) in 2011 and STAT3 GOF in 2014 has advanced our understanding of the host immunity along the JAK/STAT pathway and allowed targeted treatment approaches. We review the clinical features and pathogenesis of STAT1 and STAT3 GOF and how this has shaped new approaches to therapy.

Recent Findings: STAT1 GOF, initially described in patients with chronic mucocutaneous candidiasis (CMC) and autoimmune thyroid disease, is now recognized to cause early-onset multisystem autoimmunity and a range of infections.

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Article Synopsis
  • The JAK-STAT signaling cascade is a crucial pathway in cells that affects immune function and blood cell development, and it’s conserved across evolution.
  • Mutations in the JAK-STAT pathway are linked to an increasing number of diseases, including inherited immune disorders and conditions that mimic them due to acquired genetic changes.
  • This review covers the clinical symptoms and causes of JAK-STAT-related diseases, along with important guidelines for diagnosis and treatment.
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Article Synopsis
  • Researchers studied mutations in a gene that affects a key protein involved in cell signaling, which is linked to severe health issues like impaired immunity in patients.
  • The mutations were found to disrupt normal cell behavior by promoting excessive cell growth and responses to immune signals, specifically T cell receptor stimulation.
  • The mutant protein was shown to interfere with a regulatory protein, leading to heightened activity of important signaling pathways that contribute to cell growth and survival.
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Article Synopsis
  • DOCK8 deficiency is a serious immunodeficiency that can only be treated effectively through allogeneic hematopoietic cell transplantation (HCT), which was tested in a clinical trial using a busulfan-based regimen for its effectiveness and safety.
  • The trial involved 36 patients (mostly children and young adults) and aimed to see if HCT could improve their health and immune system within one year, with many achieving over 98% donor chimerism shortly after treatment.
  • Results showed 80.6% of participants were alive without new complications after a median follow-up of 7.4 years, and the treatment was generally well-tolerated, although some experienced immune system
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Article Synopsis
  • Hyper IgE syndrome (STAT3-HIES), also known as Job's syndrome, results from mutations in the STAT3 gene, leading to chronic respiratory infections due to compromised pulmonary defense mechanisms.
  • The study aimed to investigate how these STAT3 mutations affect the airway epithelium's ability to defend against infections, analyzing sputum properties and lung tissue from patients.
  • Findings revealed that STAT3 deficiency disrupts critical airway functions, including mucus secretion and ciliary movement, contributing to increased infection risk and inflammation in patients with this syndrome.*
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The therapeutic efficacy of donor lymphocyte infusions (DLIs) given after allogeneic hematopoietic cell transplantation (HCT) is limited by risk of graft-versus-host disease (GVHD). Post-transplantation cyclophosphamide (PTCy) effectively prevents severe GVHD, but there are limited data on outcomes of DLIs given to PTCy-treated patients. We reviewed 162 consecutive PTCy-treated patients transplanted between 2015-2022 within the Center for Immuno-Oncology at the National Cancer Institute.

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Immunological health has been challenging to characterize but could be defined as the absence of immune pathology. While shared features of some immune diseases and the concept of immunologic resilience based on age-independent adaptation to antigenic stimulation have been developed, general metrics of immune health and its utility for assessing clinically healthy individuals remain ill defined. Here we integrated transcriptomics, serum protein, peripheral immune cell frequency and clinical data from 228 patients with 22 monogenic conditions impacting key immunological pathways together with 42 age- and sex-matched healthy controls.

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Background: Thymoma presents with several autoimmune manifestations and is associated with secondary autoimmune regulator (AIRE) deficiency. Pneumonitis has recently been described as an autoimmune manifestation associated with thymoma presenting with similar clinical, radiographic, histological, and autoantibody features as seen in patients with inherited AIRE deficiency who suffer from Autoimmune PolyEndocrinopathy-Candidiasis-Ectodermal Dystrophy (APECED) syndrome.

Objectives: To treat two patients with biopsy-proven thymoma-associated pneumonitis with lymphocyte-directed immunomodulation.

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Article Synopsis
  • * A study involving 88 critically ill pediatric patients identified three immune subphenotypes linked to clinical outcomes, indicating meaningful differences in immune dysregulation between patients with and without sepsis.
  • * The research highlighted the role of STAT3 hyperactivation in lymphocytes, particularly in the sickest subgroup of patients, suggesting that targeting this dysregulated pathway could improve treatment for severe cases of multiple organ dysfunction syndrome (MODS).
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Monogenic lesions in pathways critical for effector functions responsible for immune surveillance, protection against autoinflammation, and appropriate responses to allergens and microorganisms underlie the pathophysiology of inborn errors of immunity (IEI). Variants in cytokine production, cytokine signaling, epithelial barrier function, antigen presentation, receptor signaling, and cellular processes and metabolism can drive autoimmunity, immunodeficiency, and/or allergic inflammation. Identification of these variants has improved our understanding of the role that many of these proteins play in skewing toward T2-related allergic inflammation.

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