Role of IFN-γ and IL-6 Cytokines and Their Association in Determining Susceptibility to Chronic Idiopathic Urticaria

Analysis of the Transcriptional Activity of Immune Response Genes in the Blood of Patients with Acute Urticaria

OBJECTIVE: Alterations in the transcriptional activity of some immunoregulatory genes can play a key in the pathogenesis of acute urticarial (AU). Minimally-invasive markers of the transcriptional activity of immune response genes are essential not only for predicting the severity and activity of the disease but also as a potential target for therapy. METHODS: In our research, we applied a pathway-specific polymerase chain reaction PCR array (Human Innate and Adaptive Immune Responses RT2 Profiler PCR Array, QIAGEN, Germany) to detect and verify innate and adaptive immune responses pathway-focused genes expression in patients suffering from AU and control group. RESULTS: The AU development was accompanied by an increase in the transcriptional activity of genes for a number of costimulation molecules such as CD40, CD40LG, CD80 (B7-1), and C-reactive protein and myeloperoxidase genes either. Under AU conditions, transcriptional induction of genes of several cytokines was also observed: Interferon gamma, interleukin (IL4), IL5, IL17A, tumor necrosis factor, and also chemokine CXCL8. This process was also accompanied by an increase in the transcriptional activity of the RAR-related orphan receptor C Th17 differentiation regulator, the NLRP3 inflammasome genes, and the NFKB1 transcription factor. Such changes occurred against the background of transcriptional repression of the FOXP3 gene and the Treg-dependent suppressor cytokine IL10. The expression of other studied genes did not differ significantly from the controls. CONCLUSIONS: The development of acute urticaria led to the transcriptional activation of pro-inflammatory signaling against the background of a deficiency of the suppressor link. Detected changes in gene expression can be important for targeted therapy.

Chronic spontaneous urticaria: An etiopathogenic study

Importance:

Exact etiopathogenesis of chronic spontaneous urticaria (CSU) remains elusive. Infections, pseudoallergens, autoimmunity, and contact sensitization are various postulated factors. Few studies are available measuring cytokine levels in CSU.

Objectives:

The aim was to study various etiological factors of CSU and levels of IL-6 and IFN-ϒ in cases and controls, and correlation between various etiologies with the levels of the abovementioned interleukins in the cases.

Design:

Case-control study performed over 2 years with no follow-up of the participants.

Setting:

It was a referral-center-based study.

Participants:

Sixty patients of CSU and equal age and sex-matched healthy controls were recruited on the basis of convenience sampling.

Exposures:

Biochemical and hematological investigations with hepatitis serology, thyroid function tests, anti-thyroid antibodies, and levels IL-6 and IFN-ϒ were performed in all cases and controls. All cases were subjected to ASST. Cases with all above negative tests were patch-tested with Indian standard series. Urticaria activity score (UAS7) was calculated for all the cases and repeated in patients with positive etiological factor after 3 weeks (improvement after allergen or drug avoidance, treatment of infection).

Outcomes:

To study the various etiological factors (food, infection, autoimmunity, autoreactivity, and contact sensitization) and the levels of IL-6 and IFN- γ in patients of chronic spontaneous urticaria.

Results:

Etiology was ascertained in 75% of patients (autoimmunity: 50%, contact sensitization: 21.67%, food and drug allergy: 1.67% each). Mean values of the interleukins and anti-thyroid antibodies were significantly higher in cases versus controls. Levels of IFN-ϒ were significantly elevated in patients with higher UAS7 scores.

Conclusion:

Antithyroid antibodies, ASST, and patch testing are important tools and should be considered in patients of CSU after a thorough history and history-based workup. Elevated levels of IL-6 and IFN- ϒ in cases suggest that both Th1 and Th2 type of immune responses are implicated in pathogenesis of CSU.

Markers for the involvement of endothelial cells and the coagulation system in chronic urticaria: A systematic review

Chronic urticaria (CU) is a chronic inflammatory mast cell-driven disorder. Endothelial cells (ECs) contribute importantly to key features of CU. Several markers of EC (dys)function in CU have been reported, but have not yet been systematically reviewed. In this study, we systematically reviewed and categorized all published markers of EC functions in CU through a comprehensive search in Pubmed, The Cochrane Library, Web of Science, and SCOPUS using the following Mesh terms: CU AND pathogenesis AND (vasculopathy OR microangiopathy OR ECs OR marker). In total, 79 articles were selected and the identified biomarkers were categorized according to EC (dys)function in CU. The most frequent and consistently reported upregulated biomarkers in CU skin were adhesion molecules, TF, and P-selectin. The most frequently reported upregulated and reliable biomarkers in sera of CU patients were F1+2 for coagulation cascade involvement, D-dimers for fibrinolysis, and MMP-9 for vascular permeability. Emerging biomarkers described in the selected articles were endostatin, heat shock proteins, cleaved high molecular weight kininogen, and adipokines. This systematic review contributes to the pool of growing evidence for vascular involvement in CU where EC dysfunction is present in different aspects of cell survival, maintenance of vascular structure, and coagulation/fibrinolysis balance.

The Pathogenesis of Chronic Spontaneous Urticaria: The Role of Infiltrating Cells

Chronic spontaneous urticaria is characterized by a perivascular non-necrotizing cellular infiltrate around small venules of the skin. It consists primarily of CD4(+) lymphocytes, a prominence of the T helper (Th)2 subtype but also Th1 cells, with Th17 cell-derived cytokines elevated in plasma. There are also neutrophils, eosinophils, basophils, and monocytes. Chemokines derived from mast cells and activated endothelial cells drive the process. Although the role of the cellular infiltrate has not previously been addressed, each constituent can contribute to the overall pathogenesis. It is of interest that CSU responds to corticosteroid, yet, short-term steroids do not affect autoimmunity or degranulation of mast cells, and act on margination of cells along the endothelium and chemotaxis to enter the surrounding dermis. In this review, we address each cell's contribution to the overall inflammatory response, as it is currently understood, with a view toward development of therapeutic options that impede the function of critical cells and/or their secretory products.

Mesenchymal Stem Cells: a Potential Treatment Approach for Refractory Chronic Spontaneous Urticaria

The etiopathogenesis of chronic spontaneous urticaria (CSU) is not fully elucidated, and almost 30-40% of patients are resistant to treatments; therefore, there is still a need for the development of new and effective treatments. This study aimed to develop experimental cellular therapy for CSU patients resistant to current treatment options. Autologous adipose tissue mesenchymal stem cells (MSC) were administered to 10 refractory CSU patients who were then followed up for six months. The efficacy of treatment was evaluated according to the weekly urticaria activity scores (UAS7) and drug use scores (DUS7). To observe the effect of treatment on immune cells, CD4⁺ T cell subsets were analyzed by flow cytometry, and the serum IFN-γ, TNF-α, IL2, IL-4, IL-5, IL-6, IL-10, IL-13, IL-17a, IL-21, IL-22, TGF-β1, PGE2, IDO and anti-FcεRI levels were measured using the Luminex and ELISA methods. The values obtained were compared with 10 control refractory CSU patients and five healthy controls. We found that the T cell subsets and inflammatory molecules were not affected by MSC treatment during the follow-up period. In control patients, a significant decrease was detected only at the Th2 subset, TGF-β1, PGE2, IDO and anti-FcεRI levels on the 14th day of treatment. The UAS7 and DUS7 values of the MSC-treated patients significantly decreased during the follow-up period, but in control patients, a significant but temporary decrease was seen. According to our findings, unlike conventional treatment, MSC therapy resulted in longer and more effective recovery. Our data indicate that MSCs may be an alternative and effective approach for treatment-resistant CSU patients. Graphical Abstract.

Expression of suppressor of cytokine signaling 3 (SOCS3) and interleukin-6 (-174-G/C) polymorphism in atopic conditions

Hypersensitivity of the immune system is caused by elevated immunoglobulin E (IgE) levels in the serum, in response to a discrete allergen leading to allergic reactions. IgE-mediated inflammation is regulated by the cascade of defense related signaling molecules including interleukin-6 (IL-6) that plays pivotal role in the survival and maturation of mast cells during an allergic reaction. IL-6 mediated defense responses are tightly regulated by Suppressor of Cytokine Signaling 3 (SOCS3), an inhibitory molecules of Janus Kinase-Signal Transducers and Activators of Transcription (JAK-STAT) signaling, in a negative feedback mechanism. The given study focuses on the assessment of crosstalk between SOCS3 and IL-6 to unravel the molecular significance of SOCS3 and IL-6 in the diagnosis and prognosis of allergy. The expression study of SOCS3 through real-time PCR analysis revealed, a 5.9 mean fold increase in SOCS3 expression in atopic cases in comparison to control cases. Moreover, IL-6 has, also, been found significantly enhanced in the serum level of atopic cases (26.4 pg/ml) as compared to control cases (3.686 pg/ml). Female population was found to be at a higher risk to develop atopic condition than male population as females exhibited higher expression of both SOCS3 and IL-6 than males. Furthermore, the polymorphic study of IL-6 promoter region (IL-6 174-G/C) in atopic population has reasserted the importance of SOCS3 and IL-6 in the diagnosis and prognosis of allergy. Expression of SOCS3 and IL-6 serum levels were found to be highly correlated. Therefore establishing the role of IL-6 (-174-G/C) polymorphism on the expression of SOCS3 and IL-6 in atopic cases. Notably, the study established SOCS3 and IL-6 as potential targets for the diagnosis/prognosis of allergy and for the development of reliable therapeutic strategies to control atopic conditions in the near future.

Single nucleotide polymorphisms of IL-2, but not IL-12 and IFN-γ, are associated with increased susceptibility to chronic spontaneous urticaria

BACKGROUND

A clear picture of interaction of Th1/Th2 cytokines in pathogenesis of chronic spontaneous urticaria (CSU), remains elusive. Impaired IFN-γ production and decreased levels of IL-2 have been reported. The aim of this study was to evaluate the association of Th1 cytokines; IL-2, IL-12 and IFN-γ polymorphisms with CSU.

METHODS

90 patients with CSU and 140 age-sex matched subjects were included in this study. DNA samples were evaluated through PCR-SSP assay in order to detect single nucleotide polymorphisms of IL-12 (A/C -1188) or (rs3212227), IFN-γ (A/T UTR5644) or (rs2069717) and IL-2 (G/T -330 and G/T +166) or (rs2069762 and rs2069763).

RESULTS

G allele at -330 at promoter region of IL-2 gene was overrepresented in CSU. Heterozygotes (GT) at this locus and heterozygotes at +166 of IL-2 gene (GT) were more prevalent in CSU group. Additionally, the haplotype GT for loci -330 and +166 of IL-2 gene was powerfully associated with CSU (OR (95%CI)=57.29 (8.43-112.7)).

CONCLUSIONS

SNP at position -330 and +166 of IL-2 gene are differently expressed in CSU. The haplotype GT of IL-2 at -330 and +166 might confer vulnerability to a number of immunological disorders in Iranian region.

IL-6 Transsignaling in Patients with Chronic Spontaneous Urticaria

Background

IL-6 trans-signaling is critically involved in the initiation and promotion of inflammatory and autoimmune diseases. Therefore, we investigated the clinical relevance of soluble members of IL-6 trans-signaling system in chronic spontaneous urticaria (CSU).

Methods

IL-6, interleukin 6 soluble receptor (IL-6 sR) and soluble gp130 (sgp130) were measured by ELISA method in plasma from CSU patients and the healthy subjects. The data were related to activation of the acute phase response as indicated by serum C-reactive protein (CRP) concentration and compared between patients stratified by the disease activity.

Results

Concentrations of IL-6, IL-6 sR, sgp130 in plasma and CRP in serum were significantly elevated in CSU patients compared with the healthy controls. CRP correlated significantly with IL-6 and sgp130, similarly IL-6 correlated significantly with sgp130. By contrast, CRP and IL-6 did not correlate significantly with IL-6 sR. However, significant correlation was noted between IL-6 sR and sgp130.

Conclusions

Concentrations of IL-6 and its soluble receptors were significantly elevated in patients with CSU, suggesting upregulation of the IL-6 trans-signaling in the disease. In addition, our results support the concept that the system may be involved in pathogenesis of the systemic inflammatory activation in CSU patients.