Interleukin 1 Gene Polymorphisms Presumably Participate in the Pathogenesis of Chronic Spontaneous Autoreactive Urticaria

Inhibition of interleukin‐1 with rilonacept is not effective in cold urticaria—Results of a randomized, placebo‐controlled study

Background

Cold urticaria (ColdU) is characterized by pruritic wheals following exposure of the skin to cold. Many patients show insufficient response to antihistamines, the first line treatment. Based on the high efficacy of interleukin‐1(IL‐1)‐inhibition in cold‐induced urticarial autoinflammatory diseases, we assessed the effects of rilonacept, an IL‐1 inhibitor, in ColdU patients unresponsive to standard treatment.

Methods

In this randomized, double‐blind, placebo‐controlled two‐center study, we included 20 patients with ColdU. In the first part, patients received 320 mg rilonacept or placebo (1:1) followed by weekly doses of 160 mg rilonacept or placebo for 6 weeks. In the second part, all patients received weekly 160 mg or 320 mg rilonacept for 6 weeks, open‐label. The primary endpoint was change in critical temperature threshold (CTT). Secondary endpoints included changes in quality of life impairment (Dermatology Life Quality Index, DLQI), differences of inflammatory mediators upon cold provocation and safety assessment over the study period.

Results

Baseline mean CTTs were 20.2°C (placebo) and 17.3°C (rilonacept). Mean CTTs did not change significantly during the 6‐week double‐blind treatment (placebo – 0.45°C; rilonacept +0.89°C). IL‐6, IL‐18 and HSP‐70 blood levels showed interindividual variability without significant changes during hand cold water bath provocation in placebo‐ or rilonacept‐treated patients. In contrast, DLQI significantly improved in the rilonacept (mean DLQI reduction of 3.8; p = 0.002) but not in the placebo group (mean DLQI reduction of 0). Comparing baseline with the rilonacept open‐label treatment, there were no changes in CTTs or DLQI scores.

Conclusion

IL‐1 inhibition with rilonacept did not improve ColdU, but demonstrated a good safety profile.

Clinical Trial Registration

EudraCT number: 2012‐005726‐30. ClinicalTrials.gov identifier: NCT02171416.

An update on anaphylaxis and urticaria

Notable scientific developments have taken place in the field of anaphylaxis and urticaria in recent years; they are highlighted in this review. Case-control studies, genome-wide association studies, and large omics analyses have promoted further insights into not only the underlying genetics but also the biomarkers of both anaphylaxis and urticaria. New evidence regarding IgE-dependent and non-IgE-dependent mechanisms of anaphylaxis and urticaria, including the Mas-related G protein-coupled receptor (MRGPR [formerly MRG]) signaling pathway, has been gained. Putative elicitors of anaphylactic reactions in the context of coronavirus disease 2019 (COVID-19) vaccination and impact of the COVID-19 pandemic on the management and course of chronic urticaria have been reported. Clinical progress has also been made regarding the severity grading and risk factors of anaphylaxis, as well as the distinction of phenotypes and elicitors of both diseases. Furthermore, novel treatment approaches for anaphylaxis and subtypes of urticaria have been assessed, with different outcome and potential for a better disease control or prevention.

Integrated Bioinformatics and Validation Reveal IL1B and Its Related Molecules as Potential Biomarkers in Chronic Spontaneous Urticaria

Background

The etiopathogenesis of chronic spontaneous urticaria (CSU) has not been fully understood, and there has been extensive interest in the interaction between inflammatory dermatosis and pyroptosis. This study intends to investigate the molecular mechanism of pyroptosis-related genes in CSU via bioinformatic ways, aiming at identifying the potential key biomarker.

Methods

GSE72540, the RNA expression profile dataset of CSU, was utilized as the training set, and GSE57178 as the validation set. Differently expressed pyroptosis-related genes (DEPRGs), GO, KEGG, and DO analyses were performed. The hub genes were explored by the protein–protein interaction analysis. Moreover, CIBERSORT was employed for estimating immune cell types and proportions. Then, we constructed a DEmRNA–miRNA–DElncRNA ceRNA network and a drug–gene interaction network. Finally, ELISA was used for gene expression analysis.

Results

We recognized 17 DEPRGs, whose enrichment analyses showed that they were mostly enriched in inflammatory response and immunomodulation. Moreover, 5 hub genes (IL1B, TNF, and IRF1 are upregulated, HMGB1 and P2RX7 are downregulated) were identified via the PPI network and verified by a validation set. Then immune infiltration analysis displayed that compared with normal tissue, CSU owned a significantly higher proportion of mast cells activated, but a lower proportion of T cells CD4 naive and so on. Furthermore, IL1B was statistically and positively associated with mast cells activated in CSU, and SNHG3, the upstream factor of IL1B in the ceRNA we constructed, also related with mast cells in CSU. Further analysis exhibited that the protein subcellular localization of IL1B was extracellular, according with its intercellular regulation role; IL1B was significantly correlated with key immune checkpoints; and the NOD-like receptor signaling pathway was the mainly involved pathway of IL1B based on the couple databases. What is more, the result of ELISA of CSU patients was the same as the above analyses about IL1B. In addition, the drug–gene interaction network contained 15 potential therapeutic drugs targeting IL1B, and molecular docking might make this relationship viable.

Conclusion

IL1B and its related molecules might play a key role in the development of CSU and could be potential biomarkers in CSU.

Therapeutic potential of targeting IL-1 family cytokines in chronic inflammatory skin diseases

The interleukin-1 (IL-1) family of cytokines is a central regulator of a myriad of immunological responses. It comprises several cytokines, including those belonging to the IL-1, IL-36 and IL-18 subfamilies, as well as IL-33. The IL-1 family primarily plays a role in orchestrating innate immune responses but also in adaptive immunity. Increased interest in the IL-1 family occurred following the discovery that dysregulation of IL-1 signalling underlies the pathogenesis of several monogenic auto-inflammatory diseases, characterized by sterile inflammation involving the skin and other organs. This also provided increased understanding of the role of innate immunity and the IL-1 family in polygenic auto-inflammatory skin conditions, such as neutrophilic dermatoses, as well as in some of the most common chronic inflammatory skin diseases, such as psoriasis or hidradenitis suppurativa. Several therapeutic agents have been developed to inhibit the IL-1 family members and their signalling pathways. These have shown therapeutic efficacy in several chronic inflammatory skin disorders. The aim of this review is to thoroughly describe the consequences of pathological dysregulation of IL-1, IL-33, IL-36, IL-18 pathways in dermatological conditions and to provide a forward-looking update on therapeutic strategies targeting signalling by IL-1 family cytokines.