New considerations of health disparities within allergy and immunology.

The pandemic, political upheavals, and social justice efforts in our society have resulted in attention to persistent health disparities and the urgent need to address them. Using a scoping review, we describe published updates to address disparities and targets for interventions to improve gaps in care within allergy and immunology. These disparities-related studies provide a broad view of our current understanding of how social determinants of health threaten patient outcomes and our ability to advance health equity efforts in our field. We outline next steps to improve access to care and advance health equity for patients with allergic/immunologic diseases through actions taken at the individual, community, and policy levels, which could be applied outside of our field. Key among these are efforts to increase the diversity among our trainees, providers, and scientific teams and enhancing efforts to participate in advocacy work and public health interventions. Addressing health disparities requires advancing our understanding of the interplay between social and structural barriers to care and enacting the needed interventions in various key areas to effect change.

IgG3 Antibody Response to COVID-19 Vaccination in a Patient With a Large Heavy Chain Deletion.

Vaccinations for pathogenic organisms have been utilized for decades in both the protection and diagnosis of immunodeficiency patients. Some of these immunodeficient patients may not create an adequate response to vaccination, although some who have significant aberrancies in their immune system may surprisingly create antibodies to immunizations. We present a patient with a large Ig heavy chain deletion (severe deficiency of serum IgG1, IgG2, IgG4, and IgA1) that showed a considerable response (presumably through IgG3) after the Pfizer BioNTech COVID-19 vaccination. This finding in this unique immunodeficient patient warrants further research into alternate antibody response pathways against COVID-19.

IgM Deficiency Associated With Connexin Mutation in an 18-Year-old Male.

IgM deficiency is characterized by remarkably low serum levels of IgM with normal IgG and IgA levels. These patients clinically present with recurrent infections, autoimmune disorders, and malignancies. While unknown, the proposed mechanisms explain the pathophysiology as an issue due to impaired IgG antibody response. The connexin genes encode for gap junctional proteins where mutations can cause hearing deficits and immune dysregulation. We present a unique case of an 18-year-old patient with recurrent sinusitis, diagnosed connexin-26 mutation and an IgM deficiency. An 18-year-old male with chronic sinusitis, Marfanoid joint hypermobility syndrome, and sensorineural hearing loss due to connexin-26 deficiency with bilateral cochlear implants. This patient's mutation is a GJB2 deletion located on chromosome 13 which encodes for the connexin-26 protein. The patient experienced recurrent infections, and serum immunoglobulins showed a normal IgA (84 mg/dL; normal: 70-400 mg/dL), IgG (922 mg/dL; normal: 700-1600 mg/dL) and reduced IgM (26 mg/dL; normal: 40-230 mg/dL) levels. The patient was responsive to Mumps, Measles, Rubella, and Diphtheria vaccinations among others, consistent with SIGMD diagnoses. Antibody responses to polysaccharide antigens were absent. The leukocyte counts were within normal limits. His parents are connexin-26 deficient carriers, and his older brother was diagnosed with SIGMD. Connexin-26 has been identified with multiple immunological mechanisms. Although mutations of this gene have no direct tie to antibody formation in relation to IgM, the presence of these 2 pathologies in 1 patient is intriguing and may suggest a pathophysiologic connection. We describe the first case of connexin mutation with an IgM deficiency in an 18-year-old male.

Rab13-dependent trafficking of RhoA is required for directional migration and angiogenesis.

Angiogenesis requires concomitant remodeling of cell junctions and migration, as exemplified by recent observations of extensive endothelial cell movement along growing blood vessels. We report that a protein complex that regulates cell junctions is required for VEGF-driven directional migration and for angiogenesis in vivo. The complex consists of RhoA and Syx, a RhoA guanine exchange factor cross-linked by the Crumbs polarity protein Mupp1 to angiomotin, a phosphatidylinositol-binding protein. The Syx-associated complex translocates to the leading edge of migrating cells by membrane trafficking that requires the tight junction recycling GTPase Rab13. In turn, Rab13 associates with Grb2, targeting Syx and RhoA to Tyr(1175)-phosphorylated VEGFR2 at the leading edge. Rab13 knockdown in zebrafish impeded sprouting of intersegmental vessels and diminished the directionality of their tip cells. These results indicate that endothelial cell mobility in sprouting vessels is facilitated by shuttling the same protein complex from disassembling junctions to the leading edges of cells.