Intravenous Immunoglobulin: Mechanism of Action in Autoimmune and Inflammatory Conditions.

Intravenous immunoglobulin (IVIG) is the mainstay of therapy for humoral immune deficiencies and numerous inflammatory disorders. Although the use of IVIG may be supplanted by several targeted therapies to cytokines, the ability of polyclonal normal IgG to act as an effector molecule as well as a regulatory molecule is a clear example of the polyfunctionality of IVIG. This article will address the mechanism of action of IVIG in a number of important conditions that are otherwise resistant to treatment.

Tregitopes Improve Asthma by Promoting Highly Suppressive and Antigen-Specific Tregs.

Tregitopes (T regulatory epitopes) are IgG-derived peptides with high affinity to major histocompatibility complex class II (MHCII), that are known to promote tolerance by activating T regulatory cell (Treg) activity. Here we characterized the effect of IgG Tregitopes in a well-established murine model of allergic asthma, demonstrating antigen-specific tolerance adoptive transfer of Tregitope-and-allergen-activated Tregs. Asthma is a heterogeneous chronic inflammatory condition affecting the airways and impacting over 300 million individuals worldwide.

Tolerogenic signaling of alveolar macrophages induces lung adaptation to oxidative injury.

Background: Inhaled oxidative toxicants present in ambient air cause airway epithelial injury, inflammation, and airway hyperresponsiveness. Effective adaptation to such environmental insults is essential for the preservation of pulmonary function, whereas failure or incomplete adaptation to oxidative injury can render the host susceptible to the development of airway disease.

Objective: We sought to explore the mechanisms of airway adaptation to oxidative injury.

Modulation of the Interleukin-21 Pathway with Interleukin-4 Distinguishes Common Variable Immunodeficiency Patients with More Non-infectious Clinical Complications.

Purpose: Common variable immunodeficiency (CVID) is characterized by hypogammaglobulinemia and clinical manifestations such as infections, autoimmunity, and malignancy. We sought to determine if responsiveness to interleukin-21 (IL-21), a key cytokine for B cell differentiation, correlates with distinct clinical phenotypes in CVID.

Methods: CVID subjects were recruited through the Canadian Primary Immunodeficiency Evaluative Survey registry.

Peripherally Generated Foxp3 Regulatory T Cells Mediate the Immunomodulatory Effects of IVIg in Allergic Airways Disease.

IVIg is widely used as an immunomodulatory therapy. We have recently demonstrated that IVIg protects against airway hyperresponsiveness (AHR) and inflammation in mouse models of allergic airways disease (AAD), associated with induction of Foxp3 regulatory T cells (Treg). Using mice carrying a transgene under the control of the promoter (DEREG mice), we demonstrate in this study that IVIg generates a de novo population of peripheral Treg (pTreg) in the absence of endogenous Treg.

Semaphorin 4C Protects against Allergic Inflammation: Requirement of Regulatory CD138+ Plasma Cells.

The regulatory properties of B cells have been studied in autoimmune diseases; however, their role in allergic diseases is poorly understood. We demonstrate that Semaphorin 4C (Sema4C), an axonal guidance molecule, plays a crucial role in B cell regulatory function. Mice deficient in Sema4C exhibited increased airway inflammation after allergen exposure, with massive eosinophilic lung infiltrates and increased Th2 cytokines.

Induction of Regulatory T Cells by Intravenous Immunoglobulin: A Bridge between Adaptive and Innate Immunity.

Intravenous immunoglobulin (IVIg) is a polyclonal immunoglobulin G preparation with potent immunomodulatory properties. The mode of action of IVIg has been investigated in multiple disease states, with various mechanisms described to account for its benefits. Recent data indicate that IVIg increases both the number and the suppressive capacity of regulatory T cells, a subpopulation of T cells that are essential for immune homeostasis.

Multiple sclerosis patients have a diminished serologic response to vitamin D supplementation compared to healthy controls.

Background: Vitamin D insufficiency is a risk factor for multiple sclerosis (MS), and patients do not always show the expected response to vitamin D supplementation.

Objective: We aimed to determine if vitamin D supplementation leads to a similar increase in serum 25-hydroxyvitamin-D (25(OH)D) levels in patients with MS and healthy controls (HCs).

Methods: Participants in this open-label study were female, white, aged 18-60 years, had 25(OH)D levels ⩽ 75 nmol/l at screening, and had relapsing-remitting MS (RRMS) or were HCs.

Hashimoto's thyroiditis: celebrating the centennial through the lens of the Johns Hopkins hospital surgical pathology records.

Hashimoto's thyroiditis is now considered the most prevalent autoimmune disease, as well as the most common endocrine disorder. It was initially described in 1912, but only rarely reported until the early 1950s. To celebrate this centennial, we reviewed the surgical pathology archives of the Johns Hopkins hospital for cases of Hashimoto's thyroiditis, spanning the period from May 1889 to October 2012.