Autologous Immunoglobulin Therapy in Patients With Severe Recalcitrant Atopic Dermatitis: Long-Term Changes of Clinical Severity and Laboratory Parameters

IgG from Dermatophagoides pteronyssinus (Der p)-atopic individuals modulates non-atopic thymic B cell phenotype (alfa-4/beta-7) and cytokine production (IFN-γ, IL-9, and IL-10) with direct membrane interaction

Studies about thymic B cells are scarce in the literature, but it was suggested that they can exert modulatory and regulatory functions on the immune system. Thymic B cells can play some role in regulating the most frequent allergic background worldwide, the atopy induced by the mite Dermatophagoides pteronyssinus (Der p). Here, we aimed to evaluate if the polyclonal IgG repertoire produced by Der p-atopic individuals can influence the homing and cytokine profile of human thymic B derived from non-atopic children aged less than seven days. With this purpose, we produced polyclonal IgG formulations and cultivated human thymocytes in their presence. We also assessed IgG subclasses and the direct interaction of IgG with thymic B cell membranes. Our results could demonstrate that Der p-atopic IgG could not reduce the expression of α4β7 homing molecule as observed in response to the other IgG formulations and could reduce the frequency of IFN-γ- and IL-9-producing thymic B cells compared to the mock condition. Der p-atopic IgG could also induce thymic IL-10-producing B cells compared to control conditions. The IgG derived from Der p-atopic individuals failed to diminish the population of IL-13-producing thymic B cells, unlike the reduction observed with other IgG formulations when compared to the mock condition. All IgG formulations had similar levels of IgG subclasses and directly interacted with thymic B cell membranes. Finally, we performed experiments using peripheral non-atopic B cells where IgG effects were not observed. In conclusion, our observation demonstrates that IgG induced in allergic individuals can modulate non-atopic thymic B cells, potentially generating thymic B cells prone to allergy development, which seems to not occur in mature B cells.

Immune modulation and possible pathological implications mediated by naturally produced immunoglobulin G idiotypes: from historical to recent experimental and clinical studies focused on atopic dermatitis

Since the 1950s decade, it has been suggested that a naturally produced or induced repertoire of immunoglobulin G (IgG) idiotypes may exert some immunoregulatory functions. In the last decades, some more advanced theories have suggested that the repertoire of IgG idiotypes may influence the development or control of some atopic diseases. In atopic dermatitis (AD), some evidence indicated that the IgG repertoire obtained from these patients could effectively mediate regulatory functions on thymic and peripheral CD4+ and CD8+ T cells. Furthermore, some recent clinical trials have corroborated the hypothesis that IgG from AD patients can exert regulatory functions in vivo. Here, we revised some historical aspects that yield current approaches developed in vitro and in vivo to elucidate a recently proposed theory termed "hooks without bait" that can strengthen the broad spectrum of research about evaluating different sets of IgG idiotypes and determine their immunological effects.

Mechanism underlying polyvalent IgG-induced regulatory T cell activation and its clinical application: Anti-idiotypic regulatory T cell theory for immune tolerance

The regulatory T (Treg) cells constitute a functionally defined subpopulation of T cells that modulate the immune system and maintain immune tolerance through suppression of the development of autoimmune responses to self-antigens and allergic reactions to external antigens. Reduction in the number or function of Treg cells has been suggested as a key immune abnormality underlying the development of autoimmune and allergic diseases. In vitro studies have demonstrated that purified polyvalent immunoglobulin G (IgG) from multiple healthy blood donors can exert immunomodulatory effects on Treg cells. Incubation of polyvalent human IgG with purified CD4+CD25high T cells increased the intracellular expression of interleukin (IL)-10. Intravenous administration of polyvalent human IgG induced significant expansions of CD4+ Foxp3+ Treg cells and clinical improvements in patients with autoimmune diseases. In human clinical trials, intramuscular administration of autologous total IgG significantly increased the percentage of IL-10-producing CD4+ Treg cells in the peripheral blood of healthy subjects and provided significant clinical improvements in patients with atopic dermatitis. These results suggest a clinical usefulness of polyvalent IgG-induced activation of Treg cells in human subjects. This review proposes a new hypothesis for immune tolerance mechanism by integrating the pre-existing "idiotypic network theory" and "Treg cell theory" into an "anti-idiotypic Treg cell theory." Based on this hypothesis, an "active anti-idiotypic therapy" for allergic and autoimmune diseases using autologous polyvalent IgG (as immunizing antigens) is suggested as follows: (1) Intramuscular or subcutaneous administration of autologous polyvalent IgG produces numerous immunogenic peptides derived from idiotypes of autologous IgG through processing of dendritic cells, and these peptides activate anti-idiotypic Treg cells in the same subject. (2) Activated anti-idiotypic Treg cells secrete IL-10 and suppress Th2 cell response to allergens and autoimmune T cell response to self-antigens. (3) These events can induce a long-term clinical improvements in patients with allergic and autoimmune diseases. Further studies are needed to evaluate the detailed molecular mechanism underlying polyvalent IgG-induced Treg cell activation and the clinical usefulness of this immunomodulatory therapy for autoimmune and allergic diseases.

Regulatory T Cell-Targeted Immunomodulatory Therapy for Long-Term Clinical Improvement of Atopic Dermatitis: Hypotheses and Perspectives

Atopic dermatitis (AD) is a chronically relapsing inflammatory skin disorder characterized by itching and eczematous lesions. It is often associated with a personal or familial history of allergic diseases. Allergic inflammation induced by immunoglobulin E and T-helper type 2 (Th2) cell responses to common environmental agents has been suggested to play an essential role in AD pathogenesis. The standard therapies for AD, including topical or systemic agents, focus on controlling skin inflammation. Recently developed monoclonal antibody to interleukin-4 receptor alpha or Janus kinase inhibitors can provide significant clinical improvements in patients with AD by inhibiting Th2 cell-mediated skin inflammation. However, the clinical efficacy of the Th2 cell-targeted therapy is transient and incomplete in patients with AD. Patients with AD are seeking a permanent cure. Therefore, the development of novel immunomodulatory strategies that can improve a long-term clinical outcome and provide a long-term treatment-free clinical remission of AD (disease-modifying therapy) is needed. Regulatory T (Treg) cells play a critical role in the maintenance of immune tolerance and suppress the development of autoimmune and allergic diseases. This review provides three working hypotheses and perspectives for the treatment of AD by Treg cell activation. (1) A decreased number or function of Treg cells is a critical event that causes the activation of Th2 cells, leading to the development and maintenance of AD. (2) Activation of Treg cells is an effective therapeutic approach for AD. (3) Many different immunomodulatory strategies activating Treg cells can provide a long-term clinical improvement of AD by induction of immune tolerance. The Treg cell-targeted immunomodulatory therapies for AD include allergen immunotherapy, microbiota, vitamin D, polyvalent human immunoglobulin G, monoclonal antibodies to the surface antigens of T cell or antigen-presenting cell, and adoptive transfer of autologous Treg cells or genetically engineered Treg cells expanded in vitro.

Intramuscular administration of autologous total immunoglobulin G induces immunomodulatory effects on T cells in healthy human subjects: An open-labeled prospective single-arm trial

BACKGROUND

We hypothesized that intramuscular administration of autologous total immunoglobulin G (IgG) could induce an immunomodulatory effect in human subjects. In our previous studies, we showed that intramuscular administration of autologous total IgG could induce significant clinical improvements and increases of the serum levels of interleukin-10 (IL-10) and interferon-gamma (IFN-γ) in patients with atopic dermatitis.

OBJECTIVE

To investigate the mechanism of immunomodulation induced by intramuscular administration of autologous total IgG, we evaluated changes in T cells before and after intramuscular administrations of autologous total IgG in this study.

METHODS

Thirteen healthy adults received 8 intramuscular injections of 50 mg autologous total IgG for 4 weeks (from week 0 to week 4). The percentages of IL-10- or IFN-γ-producing peripheral blood T cells, as well as serum levels of IL-10, IFN-γ, and immunoglobulins, were measured at baseline (week 0) and at weeks 4, 8, and 12.

RESULTS

The percentage of IL-10-producing CD4+ T cells was significantly increased at weeks 8 and 12 compared to baseline (P < .05), while the percentage of IFN-γ-producing CD3+ T cells was significantly increased at week 12 compared to baseline (P < .05). There were no significant differences in the serum levels of IL-10, IFN-γ, and immunoglobulins before and after intramuscular administration of autologous total IgG (P > .05). No serious adverse events were observed.

CONCLUSION

Intramuscular administration of autologous total IgG induced immunomodulatory effects on T cells in healthy human subjects. This simple intervention could be a safe, effective, and economical T cell immunomodulation method for human subjects (NCT03695757).

Successfully treated recalcitrant atopic eczema with acupoint autohemotherapy: A case report and hypothesized mechanism of the therapy

Acupoint autohemotherapy at bilateral Zusanli (ST36) and Xuehai (SP10) was used to treat a 26-year-old female patient who had suffered from recalcitrant atopic eczema (AE) for five years. The treatment was applied at a frequency of once per week for the first month, followed by a three-month period of once every other week. At the end of treatment, the patient's AE symptoms were entirely resolved, and by the end of a six-month follow-up her immunoglobulin E level had returned to the normal range. Further, there was no relapse of AE symptoms during the six-month follow-up. Therefore, we hypothesized that after the repeated treatments the local inflammatory reaction induced by autologous blood injection triggered a local immune response, followed by a systemic immune response after the repeated treatment, finally leading to the anti-inflammation and immunomodulation effects. This case suggests that acupoint autohemotherapy could be used as an effective complementary treatment for recalcitrant AE, especially in cases where other treatments have failed. Further comparative studies are needed to corroborate the value and mechanisms of this therapy.

Efficacy, Safety, and Immunomodulatory Effect of the Intramuscular Administration of Autologous Total Immunoglobulin G for Atopic Dermatitis: A Randomized Clinical Trial

Purpose

The management of patients with atopic dermatitis (AD) is often difficult. We hypothesized that repeated intramuscular administration of autologous total immunoglobulin G (IgG) could induce clinical improvement in patients with AD through immune modulation. This clinical trial was conducted to evaluate the efficacy, safety, and immunomodulatory effect of the intramuscular administration of autologous total IgG in patients with AD.

Methods

In this randomized, double-blind, placebo-controlled trial, 51 adolescent and adult patients with moderate-to-severe AD were randomized to receive 8 weekly intramuscular administrations of autologous total IgG 50 mg (n = 26) or saline (n = 25) over a 7-week period and were followed up to week 16. Changes in the clinical severity score (Eczema Area and Severity Index), affected body surface area, patient-reported Dermatology Life Quality Index (DLQI) score, laboratory biomarkers, and incidence of adverse events from baseline to week 16 were assessed.

Results

The intramuscular administration of autologous total IgG, compared with saline, decreased the clinical severity score (−64.8% vs. −20.3%, P < 0.001), reduced the affected body surface area (−53.9% vs. −19.1%, P < 0.001), improved the DLQI score (−35.4% vs. −14.4%, P = 0.015), increased serum interleukin-10 and interferon-γ levels (P = 0.011 and P = 0.003, respectively), and reduced the incidence of AD exacerbation (11.5% vs. 48.0%, P = 0.004) from baseline to week 16. No serious adverse events were observed.

Conclusions

The intramuscular administration of autologous total IgG provided clinical improvements and a systemic immunomodulatory effect in adolescent and adult patients with moderate-to-severe AD without significant side effects.

Trial Registration

Clinical Research Information Service Identifier: KCT0001597

Immunomodulatory effects induced by intramuscular administration of autologous total immunoglobulin G in patients with atopic dermatitis

BACKGROUND

Polyvalent human immunoglobulin G (IgG) preparations produced from the plasma pools of healthy blood donors have been used for the treatment of various autoimmune diseases and allergic diseases because of their anti-inflammatory and immunomodulatory effects. We hypothesized that intramuscular administration of autologous total IgG would induce immunomodulatory effects in patients with allergic diseases, based on the clinical efficacy of autologous blood therapy in patients with atopic dermatitis (AD).

METHODS

Sixteen adult AD patients with IgE-mediated sensitization to the house dust mite (Dermatophagoides farinae) received intramuscular injections of 50 mg autologous total IgG twice a week for 4 weeks. The serum levels of IgE, IgG, and IgG4 antibodies to the recombinant group 2 major allergen of Dermatophagoides farinae (Der f 2) and serum levels of interleukin (IL)-10, IL-4, IL-12, and interferon gamma (IFN-γ) were measured by enzyme-linked immunosorbent assay at baseline and at weeks 4, 8, and 12.

RESULTS

The serum level of IgE antibodies to Der f 2 was significantly decreased at 12 weeks compared with baseline (p<0.005). The serum levels of IgG and IgG4 antibodies to Der f 2 were significantly increased at 4, 8, and 12 weeks compared with baseline (p<0.05). The serum levels of IL-10 and IFN-γ were significantly increased at 4, 8, and 12 weeks compared with baseline (p<0.05). There were no significant differences in the serum levels of IL-4 or IL-12 before and after intramuscular administrations of autologous total IgG (p>0.05).

CONCLUSION

Intramuscular administration of autologous total IgG induced anti-allergic immunomodulatory effects in AD patients. Further studies are required to evaluate the detailed immunological mechanism underlying these effects.

Clinical Efficacy of Subcutaneous Allergen Immunotherapy in Patients with Atopic Dermatitis

PURPOSE

The clinical usefulness of subcutaneous allergen immunotherapy (SCIT) in the treatment of atopic dermatitis (AD) is still controversial. We analyzed the clinical efficacy of SCIT in patients with AD and the clinical characteristics of patients showing a favorable clinical response to the treatment.

MATERIALS AND METHODS

Two hundred and fifty one patients with AD sensitized to house dust mite (HDM) were treated by SCIT using HDM extract. The clinical severity of AD was measured using the standardized clinical severity scoring system for AD (SCORAD) at baseline and 12 months. A favorable clinical response to SCIT was defined as a decrease in SCORAD value at 12 months greater than 50% compared to baseline value. Severe AD was defined as a baseline SCORAD value above 50.

RESULTS

A favorable clinical response to SCIT was observed in 73.6% of patients. The proportion of patients showing a favorable clinical response to SCIT was significantly higher in patients with severe AD (90.6%) than patients with mild to moderated AD (63.7%) (p<0.001). Patients with severe AD showing a favorable clinical response had a significantly shorter duration of AD (12.3±8.5 years; mean±SD) than patients with severe AD showing no significant clinical response (20.6±10.9 years) (p<0.05) at baseline.

CONCLUSION

SCIT could be a clinically useful therapeutic option for patients with severe AD sensitized to HDM. Early initiation of SCIT might provide a favorable clinical outcome in patients with severe AD sensitized to HDM.