Clinical features of antinuclear antibody-positive patients with atopic dermatitis

Immunoglobulin E autoantibodies in atopic dermatitis associate with Type-2 comorbidities and the atopic march

BACKGROUND

Autoreactive immunoglobulin E (IgE) antibodies to self-peptides within the epidermis have been identified in patients with atopic dermatitis (AD). Prevalence, concomitant diseases, patient characteristics, and risk factors of IgE autoantibody development remain elusive. We aimed to determine IgE autoantibodies in serum samples (n = 672) from well-characterized patients with AD and controls (1.2-88.9 years).

METHODS

Atopic dermatitis patients were sub-grouped in AD with comorbid Type-2 diseases ("AD + Type 2"; asthma, allergic rhinitis, food allergy, n = 431) or "solely AD" (n = 115). Also, subjects without AD but with Type-2 diseases ("atopic controls," n = 52) and non-atopic "healthy controls" (n = 74) were included. Total proteins from primary human keratinocytes were used for the immunoassay to detect IgE autoantibodies. Values were compared to already known positive and negative serum samples.

RESULTS

Immunoglobulin E autoantibodies were found in 15.0% (82/546) of all analyzed AD-patients. "AD + Type 2" showed a higher prevalence (16.4%) than "solely AD" (9.6%). "Atopic controls" (9.6%) were comparable with "solely AD" patients, while 2.7% of healthy controls showed IgE autoantibodies. Of those with high levels of IgE autoantibodies, 15 out of 16 were patients with "AD + Type 2". AD patients with IgE autoantibodies were younger than those without. Patients with IgE autoreactivity also displayed higher total serum IgE levels. Factors that affected IgE autoantibody development were as follows: birth between January and June, cesarean-section and diversity of domestic pets.

CONCLUSIONS

Immunoglobulin E autoantibodies in AD seem to associate with the presence of atopic comorbidities and environmental factors. The potential value of IgE autoantibodies as a predictive biomarker for the course of AD, including the atopic march, needs further exploration.

Elevation of IgE in patients with psoriasis: Is it a paradoxical phenomenon?

Immunoglobulin E (IgE) elevation is a hallmark of allergic conditions such as atopic dermatitis (AD). The pathogenesis of AD is typically associated with high levels of IL-4 and IL-13 produced by activated T helper 2 (Th2) cells. Psoriasis, on the other hand, is an inflammatory skin disease mainly driven by Th17 cells and their related cytokines. Although the immunopathologic reactions and clinical manifestations are often easily distinguished in the two skin conditions, patients with psoriasis may sometimes exhibit AD-like manifestations, such as elevated IgE and persistent pruritic lesions. Given the fact that the effective T cells have great plasticity to re-differentiate in response to innate and environmental factors, this unusual skin condition could be a consequence of a cross-reaction between distinct arms of T-cell and humoral immunity. Here we review the literature concerning the roles of IgE in the development of AD and psoriasis, showing that elevated IgE seems to be an important indicator for this non-typical psoriasis.

Atopic dermatitis and autoimmunity: the occurrence of autoantibodies and their association with disease severity

Atopic dermatitis (AD) is a widespread condition that appears to be increasing in prevalence and severity worldwide, yet the underlying mechanisms are not well understood. Recent research has identified various similarities between AD and autoimmune conditions, as well as indicating that there may be an association between AD and autoimmunity. This systematic review evaluates the association between AD and autoimmunity, as well as between severity of disease in AD and autoimmunity, with an emphasis on the associations with autoantibodies. MEDLINE (1946 to December 2017) and Embase (1974 to December 2017) databases were searched. Further relevant articles were retrieved from reference lists. Only studies measuring direct indicators of autoimmunity, in humans, were included. Qualitative analysis was carried out for all studies. In addition, quantitative analysis was used to evaluate prevalence of IgE autoantibodies and anti-nuclear antibodies (ANAs) in AD patients and control subjects. The Mantel-Haenszel method was used with a random-effects model. 28 studies assessed the occurrence of autoantibodies in AD patients and 16 studies were used to evaluate association between disease severity and autoantibodies. Pooled analysis from 14 studies, involving 986 AD patients and 441 control subjects, showed that IgE autoantibodies were significantly more prevalent in patients with AD (P < 0.00001) than control subjects. Similar analysis was carried out for ANAs, with eight studies that involved 1045 AD patients and 1273 control subjects. ANAs were significantly more prevalent in patients with AD (P = 0.003). This quantitative analysis supported an association between AD and IgE autoantibodies, as well as between AD and ANAs. There was insufficient data to make similar conclusions for other indicators of autoimmunity. The weight of evidence also suggests an association between IgE autoantibodies and disease severity. There was insufficient evidence to make this link for other indicators of autoimmunity.

Flightless I Alters the Inflammatory Response and Autoantibody Profile in an OVA-Induced Atopic Dermatitis Skin-Like Disease

Atopic dermatitis (AD) is a chronic pruritic inflammatory skin disease characterized by excessive inflammation and disrupted skin barrier function. Although the etiology of AD is not completely understood, clinical and basic studies suggest increasing involvement of autoantibodies against intracellular proteins. An actin remodeling protein, Flightless I (Flii), has been shown to promote development of inflammatory mediated skin conditions and impairment of skin barrier development and function. Here, we sought to determine the effect of altering Flii expression on the development of AD and its contribution to autoimmune aspects of inflammatory skin conditions. Ovalbumin (OVA)-induced AD skin-like disease was induced in Flii heterozygous (Flii^+/−), wild-type (Flii^+/+), and Flii transgenic (Flii^Tg/Tg) mice by epicutaneous exposure to OVA for 3 weeks; each week was separated by 2-week resting period. Reduced Flii expression resulted in decreased disease severity and tissue inflammation as determined by histology, lymphocytic, and mast cell infiltrate and increased anti-inflammatory IL-10 cytokine levels and a marked IFN-γ Th₁ response. In contrast, Flii over-expression lead to a Th₂ skewed response characterized by increased pro-inflammatory TNF-α cytokine production, Th₂ chemokine levels, and Th₂ cell numbers. Sera from OVA-induced AD skin-like disease Flii^+/− mice showed a decreased level of autoreactivity while sera from Flii^Tg/Tg mice counterparts showed an altered autoantibody profile with strong nuclear localization favoring development of a more severe disease. These findings demonstrate autoimmune responses in this model of OVA-induced AD-like skin disease and suggest that Flii is a novel target, whose manipulation could be a potential approach for the treatment of patients with AD.

Immunoglobulin E-Mediated Autoimmunity

The study of autoimmunity mediated by immunoglobulin E (IgE) autoantibodies, which may be termed autoallergy, is in its infancy. It is now recognized that systemic lupus erythematosus, bullous pemphigoid (BP), and chronic urticaria, both spontaneous and inducible, are most likely to be mediated, at least in part, by IgE autoantibodies. The situation in other conditions, such as autoimmune uveitis, rheumatoid arthritis, hyperthyroid Graves’ disease, autoimmune pancreatitis, and even asthma, is far less clear but evidence for autoallergy is accumulating. To be certain of an autoallergic mechanism, it is necessary to identify both IgE autoantibodies and their targets as has been done with the transmembrane protein BP180 and the intracellular protein BP230 in BP and IL-24 in chronic spontaneous urticaria. Also, IgE-targeted therapies, such as anti-IgE, must have been shown to be of benefit to patients as has been done with both of these conditions. This comprehensive review of the literature on IgE-mediated autoallergy focuses on three related questions. What do we know about the prevalence of IgE autoantibodies and their targets in different diseases? What do we know about the relevance of IgE autoantibodies in different diseases? What do we know about the cellular and molecular effects of IgE autoantibodies? In addition to providing answers to these questions, based on a broad review of the literature, we outline the current gaps of knowledge in our understanding of IgE autoantibodies and describe approaches to address them.

Antinuclear antibodies in autoimmune and allergic diseases

Antinuclear antibodies (ANA) are primarily significant in the diagnosis of systemic connective tissue diseases. The relationship between their occurrence in allergic diseases is poorly documented. However, the mechanism of allergic and autoimmune diseases has a common thread. In both cases, an increased production of IgE antibodies and presence of ANA in selected disease entities is observed. Equally important is the activation of basophils secreting proinflammatory factors and affecting the differentiation of TH17 lymphocytes. Both autoimmune and allergic diseases have complex multi-pathogenesis and often occur in genetically predisposed individuals. The presence of antinuclear antibodies was confirmed in many systemic connective tissue diseases and some allergic diseases. Examples include atopic dermatitis, non-allergic asthma, and pollen allergy. Co-occurring allergic and autoimmune disorders induce further search for mechanisms involved in the aetiopathogenesis of both groups of diseases.

Humoral and Cellular Autoreactivity to Epidermal Proteins in Atopic Dermatitis

Atopic dermatitis (AD), a chronic relapsing inflammatory disease of the skin, is an important public health concern affecting 10-20 % of children worldwide. The etiology and pathogenesis of AD involve the interplay of genetic and environmental factors, including abnormalities in skin integrity and a skewed immune system usually driven by a Th2 phenotype in childhood with a switch to Th1 in the chronic phase of disease. Children and adults with AD commonly have elevated IgE levels directed to multiple different antigens, including aeroallergens, food allergens, and microbial proteins. IgE targeting self-antigens from epidermal proteins have been detected in up to 91 % of patients, particularly in severe persistent AD. It has been suggested that the occurrence of autoreactivity develops in early childhood. However, it is not clear yet if autoreactive IgEs in patients with AD are pathogenic or just an epiphenomenon. The fact that these autoantibodies are associated with severity and are not present in other allergic or skin diseases favors the pathogenicity of IgE-mediated autoreactivity in AD. In this review, we evaluate the pathogenesis of AD and the emerging role of autoreactivity to various keratinocyte antigens involving both the humoral and cellular components of the immune system.

Some aspects of interactivity between endocrine and immune systems required for successful reproduction

BACKGROUND

In successful reproduction, endocrine and immune systems closely interact. We here attempt to further elucidate the relationship between androgen levels, systemic activation of the immune system and reproductive success in infertile women, utilizing 2 distinct infertile patient cohorts.

METHODS

In Group 1, we investigated 322 women (ages 38.6+/-5.4 years) at initial presentation; in Group 2 125 women undergoing in vitro fertilization (169 IVF cycles, ages 38.9+/-5.5 years). In Group 1, we assessed androgens and an immune panel, previously demonstrated to discriminate between activated quiescent immune systems; in Group 2, utilizing the same immune panel, we investigated whether immune system activation relates to embryo quality in IVF cycles.

RESULTS

No individual immune test within the immune panel was associated with androgen levels. The total/free testosterone ratio (TT/FT) was, however, significantly associated with presence of gammopathies (in IgG, IgM, IgA, IgE; P=0.026). Surprisingly, immune system activation was associated with significantly improved embryo quality (P=0.008), a finding persistent after adjustment for age and repeat IVF cycles (P=0.006).

CONCLUSIONS

Association of immune system activation with improved embryo quality concurs with previously reported immune activation in association with normal functional ovarian reserve (FOR) and normal androgen levels, while, counter intuitively, hypoandrogenism and low FOR are associated with lack of immune system activation. Mild immune system activation, therefore, likely appears essential for establishment of pregnancy, and may be regulated by androgens.

Autoallergy in atopic dermatitis

The term autoallergy denotes autoimmunity accompanying an atopic disease, with antigen-specific IgE as a hallmark. This phenomenon is discussed to contribute to a chronification of the disease and to shape the immune response in chronic atopic dermatitis (AD). In this review, we highlight recent insights into the autoallergic inflammation in AD. Different mechanisms underlying the allergenicity of autoallergens are discussed at the moment: intrinsic functions modulating the immune system as well as molecular mimicry may influence the allergenic potential of these proteins. Finally, the role of specific T cells is discussed.

Cite this as: Hradetzky S, Werfel T, Roesner LM. Autoallergy in atopic dermatitis. Allergo J Int 2015; 24:16–22 DOI: 10.1007/s40629-015-0037-5

Antinuclear antibodies in atopic dermatitis: a cross-sectional study on 346 children

BACKGROUND

Atopic dermatitis (AD) is a chronic inflammatory skin disease that can be classified into an extrinsic or intrinsic type. A high percentage of patients, especially adults with the extrinsic type of AD, have been reported to show antibodies to antinuclear proteins (ANA). We aimed to study the prevalence of ANA in children with AD and to evaluate clinical differences between patients with ANA-positive and ANA-negative AD.

METHODS

A total 346 serum samples from children with active AD (mean age 5.8 years) and 117 hospital controls without known skin, inflammatory, or immune-mediated disease (mean age 7.9 years) were tested for IgG ANA with indirect immunofluorescence on HEp-2 cells, total serum IgE levels, and IgE type antibodies to food allergen panels.

RESULTS

In total, 47 patients with AD (13.6%) and 15 subjects in the control group (12.8%) were ANA positive at screening dilution 1:10 (P > 0.05). In patients with AD, ANA was found already at the age of 2 years, significantly more often in females (P < 0.005) and at slightly higher titers (up to 1:160). No differences were found in ANA positivity regarding the severity of AD or sensitization to food allergens.

CONCLUSION

No significant differences were observed between AD and the control group, or between different subtypes of AD in ANA prevalence. In both groups, ANA frequency increased with age, but in patients with AD, ANA had a tendency to appear earlier. Therefore, active AD during the early years of life could dispose selected patients towards earlier development of systemic autoreactivity and stress the need for regular follow-up of patients with ANA-positive AD.

Does "autoreactivity" play a role in atopic dermatitis?

The role of autoimmunity in atopic dermatitis (AD) is unclear. We sought to critically examine the occurrence, correlation with severity, and possible causative role of autoreactivity in patients with AD. Our systematic review of studies identified from MEDLINE included 31 experiments that described autoreactivity in patients with AD. We defined autoreactivity as in vitro or in vivo evidence of immune response to autologous human, generic human, or recombinant human proteins or other tissue/cellular components. Autoreactivity prevalence in patients with AD ranged from 23% to 91% in 14 studies involving 2644 participants, although it did not appear to vary with age, sex, or disease duration. In contrast to studies of AD, IgE autoreactivity was not found in healthy subjects or in those with allergic rhinoconjunctivitis, psoriasis, systemic lupus erythematosus, or other inflammatory diseases (8 studies of 816 participants). Two reports found a positive correlation between autoreactivity and AD severity. We suggest that autoreactivity might be playing a causative role in AD based on the magnitude and specificity of the associations found; plausible mechanisms through IgE autoantibodies, IgG autoantibodies, and T(H)1 autoreactivity; and experimental elicitation of eczematous lesions after provocation. Whether autoantibodies contribute to AD chronicity now needs to be examined in longitudinal studies.