Hemizygous nonsense variant in the moesin gene (MSN) leads to a new autoimmune phenotype of Immunodeficiency 50

Activation of the Mammalian Target of Rapamycin Pathway in Endothelial Cells in Antiphospholipid Antibody-Positive Patients with Leg Ulcers

Antiphospholipid antibody (aPL)-induced activation of the mTOR (mammalian target of rapamycin) signaling pathway in endothelial cells plays a role in the pathogenesis of vascular lesions in antiphospholipid syndrome (APS). However, there are no data on whether this mechanism also contributes to the development of skin ulcers commonly observed in APS. We investigated the activation of mTOR in skin specimens from aPL-positive and aPL-negative patients with leg ulcers. Patients with leg ulcers who had primary or secondary APS or no detectable aPLs were included in the study. Biopsies were taken from the ulcer edges and the adjacent non-ulcerated skin areas. Activation of mTORC1 (mTOR Complex1) and mTORC2 (mTOR Complex2) in endothelial cells was determined by immunohistochemical analysis of phosphorylated ribosomal S6 protein (pS6RP) and phosphorylated protein kinase B (pAKT), respectively. In all aPL-positive patients, regardless of whether they had primary or secondary APS, we found a positive immunohistochemical reaction to pS6RP (mTORC1 activation) in the endothelial cells of the ulcer samples. On the other hand, pS6RP could not be detected in samples from aPL-negative chronic venous ulcers. Furthermore, pS6RP was not present in samples taken from the unaffected skin adjacent to the ulcers in aPL-positive patients. The pAKT reaction (mTORC2) was negative in both aPL-positive and aPL-negative patients, both in the ulcers and in the periulcer skin. Activation of the mTOR pathway may contribute to ulcer development in APS. The mTORC1 may be a target for therapeutic modification in APS-associated skin ulcers.

Hemizygous Moesin (MSN) Gene Deletion in an Adult With Chronic Neutropenia

X-linked moesin-associated immunodeficiency (X-MAID) is a recently identified combined immunodeficiency caused by a mutation in the moesin (MSN) gene. It is characterized by cytopenias, hypogammaglobulinemia, poor immune response to vaccine antigens, and increased susceptibility to early-life infections. We report a patient with adult-onset neutropenia, lymphopenia, inadequate response to the pneumococcal polysaccharide vaccine (PPSV23), and recurrent bacterial infections associated with a hemizygous MSN deletion. Notably, the patient has no history of significant childhood infections, cytopenias, or hypogammaglobulinemia. Although only a few cases have been documented worldwide, we underscore the importance of whole-genome sequencing (WES) in diagnosing this atypical immunodeficiency disease in adulthood. Moreover, this report may shed light on our understanding of further variants of X-MAID and enrich the known spectrum of the disease.

Simultaneous Effects of Single-Nucleotide Polymorphisms on the Estimated Breeding Value of Milk, Fat, and Protein Yield of Holstein Friesian Cows in Hungary

This study aimed to find SNPs that have an effect on the estimated breeding values (EBVs) of milk (MY), fat (FY), and protein yield (PY) of Holstein Friesian cows in Hungary. Holstein Friesian cows (n = 2963) were genotyped on a Eurogenomics (EuroG_MDv4) chip. The EBVs for MY, FY, and PY were obtained from the Association of Hungarian Holstein Breeders (AHHB). The loci associated with the EBVs were identified via three approaches: the calculation of genetic distance of the SNPs (Fst_marker), linear regression, and haplotype association tests. Nine SNPs were significantly associated with MY, FY, and PY located on BTA 2, 5, 28, and X. Among the nine SNPs identified, BTB-00219372 on BTA 5 had a positive β coefficient for MY and a negative β coefficient for FY and PY. In addition, BovineHD3000027615 on BTA X had a positive β coefficient for both MY and PY, as well as a negative β coefficient for FY. The identified SNPs were located near several genes that remain unstudied in cattle, which are potential targets for closer scrutiny in relation to milk properties. The markers associated with two or three EBVs could be used in selection with high efficiency to accelerate genetic development and help AHHB experts achieve their breeding. Most marker effects point in the same direction on EBVs; however, we found that BTB-00219372 and BovineHD3000027615 could be used with caution to increase one EBV while decreasing the other EBV or EBVs.

Management of Patients Receiving Anticoagulation Therapy in Dental Practice: A Systematic Review

BACKGROUND

Anticoagulant drugs are a valuable tool for minimizing thrombotic risks in at-risk patients. The purpose of this study is to conduct a literature review highlighting the management of these drugs during daily clinical dental practice.

MATERIALS AND METHODS

We limited our search to English-language papers published between 1 January 1989, and 7 March 2024, in PubMed, Scopus and Web of Science that were relevant to our topic. In the search approach, the Boolean keywords "anticoagulant AND dentistry" were used.

RESULTS

Twenty-five clinical trials were included for final review from 623 articles obtained from the databases Web of Science (83), PubMed (382), and Scopus (158), eliminating duplicates and 79 off-topic items, resulting in 419 articles after removing 315 entries and confirming eligibility. Overall, these studies support the use of local hemostatic measures to manage the risk of bleeding in patients on anticoagulant therapy undergoing dental procedures and highlight the importance of greater education and collaboration among healthcare professionals.

CONCLUSIONS

Research and clinical investigation have improved understanding and management of dental procedures in patients undergoing anticoagulant or antiplatelet therapy. Hemostatic agents, clinical protocols, risk factors, and continuous education are essential for navigating the complexities of anticoagulant therapy, ensuring optimal outcomes and enhancing patient well-being.

Novel Mutation in the Moesin (MSN) Gene Leads to Immunodeficiency with Epstein-Barr Virus (EBV) Infection and Dermatomyositis-Like Symptoms

PURPOSE

Moesin (MSN) deficiency is a recently reported combined immunodeficiency, and few cases have been reported to date. We describe a Chinese patient with a novel mutation causing MSN deficiency and a novel phenotype.

METHODS

Clinical and immunological data were collected. Whole-exome sequencing was performed to identify gene mutations. MSN protein expression and T cell proliferation and activation were determined by flow cytometry. Cell migration was confirmed with a Transwell assay. Autoantibody levels were analyzed using antigen microarrays.

RESULTS

The patient was a 10-year-old boy who presented with recurrent fever, oral ulcers and dermatomyositis-like symptoms, such as periorbital edema, facial swelling, elevated creatine kinase levels, and abnormal electromyography and muscle biopsy results. Epstein-Barr virus (EBV) DNA was detected in the serum, cells and tissues of this patient. He further developed nasal-type NK/T-cell lymphoma. A novel hemizygous mutation (c.68 A > G, p.N23S) in the MSN gene was found. The immunological phenotype of this patient included persistent decreases in T and B lymphocyte counts but normal immunoglobulin IgG levels. The patient had attenuated MSN protein expression and impaired T-cell proliferation and migration. The proportions of Tfh cells and CD21low B cells in the patient were higher than those in the controls. Moreover, 82 IgG and 102 IgM autoantibodies were more abundant in the patient than in the healthy controls.

CONCLUSIONS

The novel mutation N23S is pathogenic and leads to a severe clinical phenotype. EBV infection, tumor, and dermatomyositis-like autoimmune symptoms may be associated with MSN deficiency, further expanding the understanding of the disease.

Moesin deficiency leads to lupus-like nephritis with accumulation of CXCL13-producing patrolling monocytes

Moesin is a member of the ezrin-radixin-moesin (ERM) family of proteins that link plasma membrane proteins to the cortical cytoskeleton and thus regulate diverse cellular processes. Mutations in the human moesin gene cause a primary immunodeficiency called X-linked moesin-associated immunodeficiency (X-MAID), which may be complicated by an autoimmune phenotype with kidney involvement. We previously reported that moesin-deficient mice exhibit lymphopenia similar to that of X-MAID and develop a lupus-like autoimmune phenotype with age. However, the mechanism through which moesin defects cause kidney pathology remains obscure. Here, we characterized immune cell infiltration and chemokine expression in the kidney of moesin-deficient mice. We found accumulation of CD4+ T and CD11b+ myeloid cells and high expression of CXCL13, whose upregulation was detected before the onset of overt nephritis. CD4+ T cell population contained IFN-γ-producing effectors and expressed the CXCL13 receptor CXCR5. Among myeloid cells, Ly6Clo patrolling monocytes and MHCIIlo macrophages markedly accumulated in moesin-deficient kidneys and expressed high CXCL13 levels, implicating the CXCL13-CXCR5 axis in nephritis development. Functionally, Ly6Clo monocytes from moesin-deficient mice showed reduced migration toward sphingosine 1-phosphate. These findings suggest that moesin plays a role in regulating patrolling monocyte homeostasis, and that its defects lead to nephritis associated with accumulation of CXCL13-producing monocytes and macrophages.

TRPA1 Covalent Ligand JT010 Modifies T Lymphocyte Activation

Transient Receptor Potential Ankyrin 1 (TRPA1) is a non-selective cation channel involved in sensitivity to a plethora of irritating agents and endogenous mediators of oxidative stress. TRPA1 influences neuroinflammation and macrophage and lymphocyte functions, but its role is controversial in immune cells. We reported earlier a detectable, but orders-of-magnitude-lower level of Trpa1 mRNA in monocytes and lymphocytes than in sensory neurons by qRT-PCR analyses of cells from lymphoid organs of mice. Our present goals were to (a) further elucidate the expression of Trpa1 mRNA in immune cells by RNAscope in situ hybridization (ISH) and (b) test the role of TRPA1 in lymphocyte activation. RNAscope ISH confirmed that Trpa1 transcripts were detectable in CD14+ and CD4+ cells from the peritoneal cavity of mice. A selective TRPA1 agonist JT010 elevated Ca2+ levels in these cells only at high concentrations. However, a concentration-dependent inhibitory effect of JT010 was observed on T-cell receptor (TcR)-induced Ca2+ signals in CD4+ T lymphocytes, while JT010 neither modified B cell activation nor ionomycin-stimulated Ca2+ level. Based on our present and past findings, TRPA1 activation negatively modulates T lymphocyte activation, but it does not appear to be a key regulator of TcR-stimulated calcium signaling.

Retinopathy as an initial sign of hereditary immunological diseases: report of six families and challenges in eye clinic

Introduction

Retinal degenerative or inflammatory changes may occur with hereditary immunological disorders (HID) due to variants in approximately 20 genes. This study aimed to investigate if such retinopathy may present as an initial sign of immunological disorders in eye clinic.

Methods

The variants in the 20 genes were selected from in-house exome sequencing data from 10,530 individuals with different eye conditions. Potential pathogenic variants were assessed by multistep bioinformatic analysis. Pathogenic variants were defined according to the ACMG/AMP criteria and confirmed by Sanger sequencing, co-segregation analysis, and consistency with related phenotypes. Ocular clinical data were thoroughly reviewed, especially fundus changes.

Results

A total of seven pathogenic variants in four of the 20 genes were detected in six probands from six families, including three with hemizygous nonsense variants p.(Q308*), p.(Q416*), and p.(R550*) in MSN, one with homozygous nonsense variants p.(R257*) in AIRE, one with compound heterozygous nonsense variants p.(R176*) and p.(T902*) in LAMB2, and one with a known c.1222T>C (p.W408R) heterozygous variant in CBL. Ocular presentation, as the initial signs of the diseases, was mainly retinopathy mimicking other forms of hereditary retinal degeneration, including exudative vitreoretinopathy in the three patients with MSN variants or tapetoretinal degeneration in the other three patients. Neither extraocular symptoms nor extraocular manifestations were recorded at the time of visit to our eye clinic. However, of the 19 families in the literature with retinopathy caused by variants in these four genes, only one family with an AIRE homozygous variant had retinopathy as an initial symptom, while the other 18 families had systemic abnormalities that preceded retinopathy.

Discussion

This study, for the first time, identified six unrelated patients with retinopathy as their initial and only presenting sign of HID, contrary to the previous reports where retinopathy was the accompanying sign of systemic HID. Recognizing such phenotype of HID may facilitate the clinical care of these patients. Follow-up visits to such patients and additional studies are expected to validate and confirm our findings.

Positive Newborn Screening for Severe Combined Immunodeficiency: What Should the Pediatrician Do?

Severe combined immunodeficiency (SCID) is a group of diseases characterized by low T-cell count and impaired T-cell function, resulting in severe cellular and humoral immune defects. If not diagnosed and treated promptly, infants affected by this condition can develop severe infections which will result in death. Delayed treatment can markedly reduce the survival outcome of infants with SCID. T-cell receptor excision circle (TREC) levels are measured on newborn screening to promptly identify infants with SCID. It is important for primary care providers and pediatricians to understand the approach to managing infants with positive TREC-based newborn screening as they may be the first contact for infants with SCID. Primary care providers should be familiar with providing anticipatory guidance to the family in regard to protective isolation, measures to minimize the risk of infection, and the coordination of care with the SCID coordinating center team of specialists. In this article, we use case-based scenarios to review the principles of TREC-based newborn screening, the genetics and subtypes of SCID, and management for an infant with a positive TREC-based newborn screen.