Up-regulation of chemokine C-C ligand 2 (CCL2) and C-X-C chemokine 8 (CXCL8) expression by monocytes in chronic idiopathic urticaria

Research progress in the pathogenesis of chronic urticaria

Chronic urticaria is very common in clinic, but its pathogenesis is not fully elucidated. Most patients can't find the exact cause, resulting in misdiagnosis or delayed treatment. Previous studies have found that mast cell activation is the central link in the pathogenesis of chronic urticaria. Genetics, autoimmune, coagulation disorders, and infection may also be involved in the pathophysiological process of chronic urticaria. With the deepening of research, more immune and non-immune mechanisms have been gradually revealed in the pathogenesis of chronic urticaria, such as the interaction of immune cells in the microenvironment of urticaria, intestinal flora and metabolism, neuroimmunity, environmental factors and hormones. Clarifying the pathogenesis of chronic urticaria will help to find more treatment targets and provide more diversified ideas for clinical diagnosis and treatment.

Involvement of CCL2 and CH25H Genes and TNF signaling pathways in mast cell activation and pathogenesis of chronic spontaneous urticaria

Chronic spontaneous urticaria (CSU), a mast cell-driven disease, substantially affects the quality of life. While genetics affect CSU susceptibility and severity, the specific genetic factors associated with mast cell activation in CSU remain elusive. We aimed to identify key genetic factors and investigate their roles in CSU pathogenesis. Two gene expression datasets from the Gene Expression Omnibus were merged and validated using principal component analysis and boxplots. The merged dataset was subjected to limma and weighted gene co-expression network analyses. Genes whose expression correlated highly with CSU were identified and analyzed using Gene Set Enrichment Analysis (GSEA), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. As GSEA, GO, and KEGG analyses highlighted the importance of chemokine (C-C motif) ligand 2 (CCL2) and cholesterol 25-hydroxylase (CH25H) gene and tumor necrosis factor (TNF) signaling pathways in CSU; the three corresponding genes were knocked down in human mast cell line-1 (HMC-1), followed by incubation with thrombin to mimic CSU pathogenesis. CCL2, CH25H, and TNF knockdown reduced excitability and cytokine production in HMC-1. Our findings suggest that genes involved in the CCL2, CH25H, and TNF pathways play crucial roles in CSU pathogenesis, providing insights into potential therapeutic targets for CSU treatment.

Assessment of selected interleukins (IL-6, IL-17A, IL-18, IL-23) and chemokines (RANTES, IP-10) in children with acute and chronic urticaria

BACKGROUND

Urticarial lesions develop as a result of the activation of mast cells which, through the release of mediators, influence the formation of local inflammatory infiltrates. Changes in the expression of many cytokines and chemokines are observed in the course of urticaria. The aim of the study was to evaluate serum levels of interleukin (IL)-6, IL-17A, IL-18, IL-23, regulated on activation, normal T cell expressed and secreted (RANTES) and interferon (IFN)-γ-inducible protein-10 (IP-10) in children with acute urticaria and exacerbation of chronic urticaria in comparison to healthy volunteers. Moreover, we made an attempt to identify factors associated with the acute phase of urticaria and factors predicting the course of the disease among the studied parameters.

METHODS

We retrospectively analyzed 32 children with acute urticaria and 32 children with chronic urticaria. The control group consisted of 40 healthy children. Each patient was clinically evaluated. Serum concentrations of selected cytokines and chemokines were determined by using enzyme-linked immunosorbent assay.

RESULTS

Patients with acute and chronic urticaria had higher concentrations of IL-6 and IL-17A (p < 0.001) and lower concentrations of IL-18, IL-23, RANTES and IP-10 (p < 0.001) as compared to the control group. A significant association between IL-6 and IP-10 with the acute phase of urticaria has been demonstrated. There was no correlation of the studied cytokines and chemokines with disease activity.

CONCLUSIONS

In children with acute phase of urticaria, the cytokine serum concentration differs compared to healthy subjects. IL-6 and IP-10 seem to be useful in differentiating children with acute phase of urticaria and healthy ones. The search for factors predicting the course of the disease requires further studies.

Features of the functioning of innate immunity in children with chronic idiopathic urticaria

Aim. To study the features of the functioning of innate immunity in children with chronic idiopathic urticaria.

Materials and methods. The study included 28 children of both sexes aged 6–16 years with chronic idiopathic urticaria (CIU). The median age of the patients was 8 years (p = 0.045). Clinical research methods included an analysis of complaints and anamnestic data, as well as an objective examination of the child (dynamics of urticaria, severity of itching, the presence of angioedema). Immunological techniques included determination of the number of monocytes expressing CD14+CD282+, CD14+CD284+, CD14+CD289+, the number of peripheral blood lymphocytes expressing CD3+CD16+, the levels of immunoglobulin (Ig) E, lactoferrin, interferon (IFN) γ, interleukin (IL)4, and IL-6, and a nitroblue tetrazolium test.

Results. In the course of the study, an increase in the expression of Toll-like receptors TLR2 and TLR4 by monocytes, a decrease in the expression of TLR9 by monocytes, a significant rise in lactoferrin levels, a slight decrease in the number of natural killer (NK) cells, a decrease in microbicidal activity and adaptive reserves, a rise in IgE levels, a decrease in IL-4 levels, and an increase in IFNγ and IL-6 were revealed in children with CIU.

Conclusion. The immunological changes revealed during the study indicate multidirectional expression of Toll-like receptors, disturbances in the work of the cellular components of innate immunity, and a launch of a proinflammatory cytokine cascade in children with CIU, which can serve as a mainstay for the development of new schemes for personalized therapy of CIU in children.

Asian herbal medicine and chronic urticaria: which are the therapeutic perspectives?

Chronic urticaria (CU) is a pathologic condition marked by the emergence of wheals, angioedema, or both for more than six weeks. The improper activation and degranulation of mast cells is the triggering event, which results in the production of various mediators such as histamine, leukotrienes, PAF, chemokines, and cytokines. Antihistamines are currently the most common pharmacological treatment for urticaria, but corticosteroids and monoclonal antibodies can also be employed. Patients who have been taking antihistamines for a long time are often looking for alternatives. Whole plants, portions of plants, or single extracted active compounds are all used in phytomedicine. Plant elements are frequently combined to create formulations that can be utilized to treat a variety of pathological disorders. Anti-inflammatory and/or anti-allergic properties are found in several herbs regularly used in herbal formulations. Antioxidant properties are also present in some of the constituents. Exogenous antioxidants have been shown to improve the progression of autoimmune disorders in numerous studies. The aim of this review is to identify the most common herbs used to treat chronic urticaria, and to characterize their efficacy, mechanisms of action, and risk/benefit ratio in comparison to western treatment, and also to find less often used formulations and assess their therapeutic efficacy, safety profile, and potential for wider use.

The Role of Crosstalk of Immune Cells in Pathogenesis of Chronic Spontaneous Urticaria

Chronic spontaneous urticaria (CSU) is defined as recurrent episodes of spontaneous wheal development and/or angioedema for more than six weeks and at least twice a week. The core link in the pathogenesis of CSU is the activation of mast cells, T cells, eosinophils, and other immune cells infiltrating around the small venules of the lesion. Increased vascular permeability, vasodilatation, and recruitment of inflammatory cells directly depend on mast cell mediators’ release. Complex regulatory systems tightly influence the critical roles of mast cells in the local microenvironment. The bias toward Th2 inflammation and autoantibodies derived from B cells, histamine expressed by basophils, and initiation of the extrinsic coagulation pathway by eosinophils or monocytes exerts powerful modulatory influences on mast cells. Cell-to-cell interactions between mast cells and eosinophils/T cells also are regulators of their function and may involve CSU’s pathomechanism. This review summarizes up-to-date knowledge regarding the crosstalk between mast cells and other immune cells, providing the impetus to develop new research concepts and treatment strategies for CSU.

Precursors to Systemic Sclerosis and Systemic Lupus Erythematosus: From Undifferentiated Connective Tissue Disease to the Development of Identifiable Connective Tissue Diseases

The pathogenesis of connective tissue diseases (CTDs), such as systemic lupus erythematosus (SLE) and systemic sclerosis (SSc), is characterized by derangements of the innate and adaptive immune system, and inflammatory pathways leading to autoimmunity, chronic cytokine production, and chronic inflammation. The diagnosis of these diseases is based on meeting established criteria with symptoms, signs and autoantibodies. However, there are pre-clinical states where criteria are not fulfilled but biochemical and autoimmune derangements are present. Understanding the underlying processes responsible for disease pathogenesis in pre-clinical states, which place patients at increased risk for the development of established connective tissue diseases, represents an opportunity for early identification and potentially enables timely treatment with the goal of limiting disease progression and improved prognosis. This scoping review describes the role of the innate and adaptive immune responses in the pre-clinical states of undifferentiated CTD at risk for SSc and prescleroderma, the evolution of antibodies from nonspecific to specific antinuclear antibodies prior to SLE development, and the signaling pathways and inflammatory markers of fibroblast, endothelial, and T cell activation underlying immune dysregulation in these pre-clinical states.

Platelet Count and IgE Level in Chronic Idiopathic Urticaria: A Case-control Study

BACKGROUND AND AIM

Chronic Urticaria is an allergic disorder that affects about 0.5 to 5% of the population in different communities. The disease's chronic course and long-term onset impose high economic and psychological costs on communities, adversely affecting individual and social life. Platelets play a role in various pathophysiological processes, including inflammation and immunology. Growing evidence suggests that platelets are actively involved in the pathogenesis of various inflammatory disorders, including inflammatory skin diseases. This study investigated the relationship between platelet and immunoglobulin-E markers and chronic idiopathic urticaria.

MATERIALS AND METHODS

In the present case-control study, for the study population, patients with chronic idiopathic urticaria were referred to the Asthma and Allergy Clinic, and their caregivers were selected as the case and control groups, respectively. In this study, the mean platelet count (PLT), mean platelet volume (MPV), platelet distribution width (PDW), and Total IgE values were simultaneously measured in the case and control groups. After taking 5CCs of venous blood, a blood sample was sent to the laboratory for platelet and IgE marker measurements.

RESULTS

100 patients and 100 healthy persons were evaluated in this study. The mean age in the case group was 34.95, and in the control group was 35.78 years. The results showed that the mean values of PLT, MPV, PDW, and Total IgE in the case group were 12.86, 9.83, 252190, and 147.05, respectively. The mean values of PLT, MPV, PDW, and Total IgE in the control group were 16.93, 7.53, 231410, and 15.29, respectively, which was statistically significant (P = 0.001). Moreover, total IgE in the Autologous Serum Skin Test (ASST) positive group was higher than ASST negative group and was statistically significant (P = 0.001).

CONCLUSION

The study results indicate the possible role of platelets in urticaria and inflammation. MPV in patients with chronic urticaria was higher than in the control group. The present study showed no significant relationship between the severity of urticaria and platelet markers, but there was a significant relationship between the severity of urticaria and ASST. Moreover, the severity of urticaria was higher in the positive skin test group.

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.

Abnormalities in Gut Microbiota and Metabolism in Patients With Chronic Spontaneous Urticaria

Background

Increasing evidence suggests that the gut microbiome plays a role in the pathogenesis of allergy and autoimmunity. The association between abnormalities in the gut microbiota and chronic spontaneous urticaria (CSU) remains largely undefined.

Methods

Fecal samples were obtained from 39 patients with CSU and 40 healthy controls (HCs). 16S ribosomal RNA (rRNA) gene sequencing (39 patients with CSU and 40 HCs) and untargeted metabolomics (12 patients with CSU and 12 HCs) were performed to analyze the compositional and metabolic alterations of the gut microbiome in CSU patients and HCs.

Results

The 16S rRNA gene sequencing results showed a significant difference in the β-diversity of the gut microbiota, presented as the Jaccard distance, between CSU patients and HCs. No significant differences were found in the α-diversity of the gut microbiota between patients and HCs. At the phylum level, the major bacteria in the gut microbiome of patients with CSU were Firmicutes, Bacteroidetes, Proteobacteria, and Actinobacteria. At the genus level, Lactobacillus, Turicibacter, and Lachnobacterium were significantly increased and Phascolarctobacterium was decreased in patients with CSU. PICRUSt and correlation analysis indicated that Lactobacillus, Turicibacter, and Phascolarctobacterium were positively related to G protein-coupled receptors. Metabolomic analysis showed that α-mangostin and glycyrrhizic acid were upregulated and that 3-indolepropionic acid, xanthine, and isobutyric acid were downregulated in patients with CSU. Correlation analysis between the intestinal microbiota and metabolites suggested that there was a positive correlation between Lachnobacterium and α-mangostin.

Conclusions

This study suggests that disturbances in the gut microbiome composition and metabolites and their crosstalk or interaction may participate in the pathogenesis of CSU.

Differential role of lipoteichoic acids isolated from Staphylococcus aureus and Lactobacillus plantarum on the aggravation and alleviation of atopic dermatitis

Lipoteichoic acid (LTA), a cell wall component of gram-positive bacteria, up-regulates inflammatory cytokine production through the toll-like receptor 2 (TLR2) signaling pathway, and also contributes to anti-inflammatory responses against immune cells stimulated by lipopolysaccharides. In the current study, we examined the effects of LTAs isolated from Staphylococcus aureus (aLTA) and Lactobacillus plantarum (pLTA) on the aggravation and alleviation of atopic dermatitis (AD). aLTA strongly induced CCL2 production in THP-1 cells. CCL2 was regulated by the TLR2 pathway including the activation of IRAK2, NF-κB and JNK. CCL2 induced Th2 polarization of CD4+T cells through induction of interleukin (IL)-2, -4, and -5 and inhibition of interferon-gamma (IFN-γ). CCL2 levels and immunoglobulin E (IgE) production were increased in aLTA-injected mice. On the other hand, pLTA moderately affected CCL2 production and it inhibited aLTA-mediated CCL2 production. The serum levels of CCL2 and IgE were inhibited by pLTA pre-injection followed by aLTA reinjection, which resulted in the alleviation of irritant contact dermatitis (ICD) symptoms. Our results suggest that S. aureus infection causes an increase in CCL2 production, and may exacerbate atopic dermatitis (AD)-like symptoms through the excessive IgE production. Alternatively, pLTA alleviated AD-like symptoms by inhibiting aLTA-induced CCL2 and IgE production.

Stress, pseudoallergens, autoimmunity, infection and inflammation in chronic spontaneous urticaria

Chronic spontaneous urticaria (CSU) is often associated with organ specific autoimmunity but is rarely caused by food allergy. Colourings and preservatives in pre-packaged foods, so called pseudoallergens, have also been implicated. Factors that promote inflammation or reduce anti-inflammatory mechanisms may however, predispose susceptible individuals to CSU. Chronic underlying infection and mental and emotional stress can sometimes precede the onset of CSU and once established can exacerbate the symptoms. There is early evidence of dysbiosis within the gastrointestinal tract in people with CSU and reduced levels of vitamin D are also evident. The latter may be related to the importance of vitamin D3 in increasing T regulatory function which can control a tendency to autoimmunity. It is quite possible that a state of on-going chronic inflammation with reduced anti-oxidant mechanisms may underlie the not infrequent association between CSU and metabolic syndrome. Effective treatment of CSU should involve the use of anti-histamines, intermittent steroids and anti-IgE therapy. For recalcitrant disease immune modulatory therapy has a place. However, talking therapies that reduce stress and anxiety, vitamin D3 supplementation, correction of intestinal dysbiosis and treatment of any chronic infection should also be considered.

Omalizumab normalizes the gene expression signature of lesional skin in patients with chronic spontaneous urticaria: A randomized, double-blind, placebo-controlled study

BACKGROUND

Omalizumab, a humanized recombinant monoclonal anti-IgE antibody, proved to be effective in patients with chronic spontaneous urticaria (CSU), including severe and treatment-refractory CSU. Here, we report omalizumab's effect on gene expression in skin biopsies from CSU patients enrolled in a double-blind, placebo-controlled study.

METHODS

Chronic spontaneous urticaria patients (18-75 years) were randomized to either 300 mg omalizumab (n = 20) or placebo (n = 10) administered s.c. every 4 weeks for 12 weeks (NCT01599637). Lesional and nonlesional skin biopsies were collected from the same area of consenting patients and assessed at baseline and on Day 85 compared with skin biopsies from the same area of 10 untreated healthy volunteers (HVs). Gene expression data were generated using Affymetrix HG-U133Plus2.0 microarrays. Statistical analyses were performed using R packages.

RESULTS

At baseline, 63 transcripts were differentially expressed between lesional and nonlesional skin. Two-thirds of these lesional signatures were also differentially expressed between lesional and HV skin. Upon treatment with omalizumab, >75% of lesional signatures changed to reflect nonlesional skin expression levels (different vs placebo, P < 0.01). Transcripts upregulated in lesional skin (vs nonlesional and/or HV skin) suggested increased mast cell/leukocyte infiltration (FCER1G, C3AR1, CD93, S100A8, and S100A9), increased oxidative stress, vascularization (CYR61), and skin repair events (KRT6A, KRT16). Lesional signatures were not modulated by treatment in nonresponders (defined based on UAS7 longitudinal changes ≥16).

CONCLUSION

Omalizumab, in treatment responders, reverted transcriptional signatures associated with CSU lesion phenotype to reflect nonlesional/HV expression levels; this is consistent with observed omalizumab-mediated clinical improvement observed in patients with CSU.

Senescent cell clearance by the immune system: Emerging therapeutic opportunities

Senescent cells (SCs) arise from normal cells in multiple organs due to inflammatory, metabolic, DNA damage, or tissue damage signals. SCs are non-proliferating but metabolically active cells that can secrete a range of pro-inflammatory and proteolytic factors as part of the senescence-associated secretory phenotype (SASP). Senescent cell anti-apoptotic pathways (SCAPs) protect SCs from their own pro-apoptotic SASP. SCs can chemo-attract immune cells and are usually cleared by these immune cells. During aging and in multiple chronic diseases, SCs can accumulate in dysfunctional tissues. SCs can impede innate and adaptive immune responses. Whether immune system loss of capacity to clear SCs promotes immune system dysfunction, or conversely whether immune dysfunction permits SC accumulation, are important issues that are not yet fully resolved. SCs may be able to assume distinct states that interact differentially with immune cells, thereby promoting or inhibiting SC clearance, establishing a chronically pro-senescent and pro-inflammatory environment, leading to modulation of the SASP by the immune cells recruited and activated by the SASP. Therapies that enhance immune cell-mediated clearance of SCs could provide a lever for reducing SC burden. Such therapies could include vaccines, small molecule immunomodulators, or other approaches. Senolytics, drugs that selectively eliminate SCs by transiently disabling their SCAPs, may prove to alleviate immune dysfunction in older individuals and thereby accelerate immune-mediated clearance of SCs. The more that can be understood about the interplay between SCs and the immune system, the faster new interventions may be developed to delay, prevent, or treat age-related dysfunction and the multiple senescence-associated chronic diseases and disorders.

Early intervention with mesenchymal stem cells prevents nephropathy in diabetic rats by ameliorating the inflammatory microenvironment

Diabetic nephropathy (DN) is a major complication of diabetes and represents the leading cause of end-stage renal disease. Mesenchymal stem cell (MSC) treatment has been demonstrated to be effective in DN models by reducing albuminuria and attenuating glomerular injury; however, limited in-depth understanding of the underlying mechanism and a lack of clinical trials hinders its clinical use. Additionally, most of these experimental studies were conducted on the advanced stage of nephropathy, which is difficult to reverse and consequently showed limited therapeutic efficacy. We sought to evaluate whether early intervention by MSCs has the potential to prevent DN onset and progression as well as protect kidney function when intravenously administered to rats with diabetes. Diabetes was induced in adult male SD rats by streptozotocin (STZ) injection (55 mg/kg, i.p.). The diabetic rats were injected with or without bone marrow-derived MSCs (5×10⁶ per rat), via tail vein at 2, 4, 5 and 7 weeks after diabetes onset. Fasting blood glucose (FBG), blood urea nitrogen (BUN) and serum creatinine (Scr) levels in serum samples and glycosuria (GLU), microalbumin (MAU), and albumin to creatinine ratio (ACR) in urine samples were determined. Renal pathology and immunohistochemistry (IHC) for CD68, MCP-1, fibronectin (FN), transforming growth factor-β (TGF-β) and pro-inflammatory cytokines were also performed. Expression levels of the above factors as well as interleukin-10 (IL-10), and epidermal growth factor (EGF) were assessed by qPCR and multiplex bead-based suspension array system, respectively. Additionally, MSC tracing in vivo was performed. Ex vivo, peritoneal macrophages were co-cultured with MSCs, and expression of inflammatory cytokines was detected as well. MSC treatment profoundly suppressed renal macrophage infiltration and inflammatory cytokine secretion in diabetic rats, resulting in prominently improved kidney histology, systemic homeostasis, and animal survival, although no significant effect on hyperglycemia was observed. Engrafted MSCs were primarily localized in deteriorated areas of the kidney and immune organs 48 h after infusion. MSC treatment upregulated serum anti-inflammatory cytokines IL-10 and EGF. Ex vivo, MSCs inhibited lipopolysaccharide (LPS)-stimulated rat peritoneal macrophage activation via the downregulation of inflammatory-related cytokines such as IL-6, MCP-1, tumor necrosis factor-α (TNF-α) and IL-1β. Our results demonstrated that early intervention with MSCs prevented renal injury via immune regulation in diabetic rats, which restored the homeostasis of the immune microenvironment, contributing to the prevention of kidney dysfunction and glomerulosclerosis.

Elevated Plasma Level of Interferon-λ1 in Chronic Spontaneous Urticaria: Upregulated Expression in CD8(+) and Epithelial Cells and Induction of Inflammatory Cell Accumulation

Interferon- (IFN-) λ1 is regarded as a potent bio-active molecule in innate immunity. However, little is known about its role in chronic spontaneous urticaria (CSU). We therefore investigated expression of IFN-λ1 in CSU, its cellular location, and its influence on inflammatory cell accumulation by using flow cytometry analysis, skin tissue dispersion, immunohistochemical stain, and a mouse peritoneal inflammation model. The results showed that level of IFN-λ1 was 2.0-fold higher in plasma of the patients with CSU than the level in healthy control (HC) subjects. Among leukocytes examined, only CD8(+) T cells expressed more IFN-λ1 in CSU blood. Double labeling immunohistochemical staining revealed that IFN-λ1(+) inflammatory cells such as mast cells, eosinophils, B cells, neutrophils, and macrophages were mainly located in dermis, whereas epidermis tissue highly expressed IFN-λ1. IFN-λ1 induced a dose-dependent increase in number of eosinophils, lymphocytes, mast cells, macrophages, and neutrophils in the peritoneum of mice at 6 h following injection, which was inhibited by pretreatment of the animals with anti-intercellular adhesion molecule- (ICAM-) 1 and/or anti-L-selectin antibodies. In conclusion, IFN-λ1 is likely to play a role in the pathogenesis of CSU. Blocking IFN-λ1 production may help to reduce the accumulation of inflammatory cells in the involved CSU skin.

Gene expression profiles in chronic idiopathic (spontaneous) urticaria

BACKGROUND

The pathophysiology of chronic idiopathic (spontaneous) urticaria (CIU) is poorly understood.

OBJECTIVE

We hypothesized that a study of gene expression in active lesions from patients with CIU would uncover unexpected associations.

METHODS

We enrolled eight patients with CIU and six healthy controls, and obtained 4 mm punch biopsy specimens of active lesions and unaffected skin of patients with CIU and of skin from normal controls. Routine histologic evaluation was performed, RNA was isolated, and gene expression data were assessed. Due to technical reasons, the final evaluation included six samples of lesional skin, six samples of nonlesional skin, and five samples of normal skin.

RESULTS

As expected, lesional skin had more inflammatory cells per high-powered field (mean ± SE, 96 ± 6) than did samples from nonlesional skin of the subjects with CIU (17 ± 2) (p < 0.01). Lesions of CIU showed significant upregulation of 506 genes and reduced expression of 51 genes. Those most upregulated were predominantly involved in cell adhesion (e.g., selectin E [SELE]), cell activation (e.g., CD69), and chemotaxis (e.g., CCL2). Twelve independent canonical pathways with p ≤ 0.001 were identified (including intracellular kinase pathways (RAs-related nuclear protein [RAN] and Janus activated kinase/interferon), cytokine signaling pathways (IL-9, IL10, and IFN), a strong inflammatory response (interferon, IL-9, IL-10, inducible nitric oxide synthase and glucocorticoid pathways) and increased cell proliferation (RAN signaling, cell cycle control, and tRNA charging).

CONCLUSIONS

This preliminary study describes a method to study gene activation in urticarial lesions and demonstrated a strong inflammatory response with a large variety of activated genes that are distinct from those reported with other dermatologic conditions.

Vitamin D as a Marker for Disease Severity in Chronic Urticaria and Its Possible Role in Pathogenesis

BACKGROUND

Chronic urticaria is defined as repeated episodes of wheals lasting for 6 weeks or longer. Nowadays, the role of vitamin D in various chronic diseases is a matter of great interest, but limited data is available on the vitamin D status in patients with chronic urticaria.

OBJECTIVE

The goal of this study was to investigate the relationship between vitamin D status and clinical characteristics of chronic urticaria.

METHODS

The clinical records of 72 patients with chronic urticaria, 26 with acute urticaria and 26 with atopic dermatitis, along with 72 healthy controls, were retrospectively reviewed.

RESULTS

The serum 25-(OH)D3 level was found to be significantly reduced in patients with chronic urticaria compared to those in the other groups. In particular, the proportion of patients with critically low vitamin D levels (<10 ng/ml) was significantly higher in the chronic urticaria group than in the other groups. The serum vitamin D levels showed significant negative associations with urticaria activity score and disease duration. In addition, serum vitamin D levels were significantly lower in subjects with a positive autologous serum skin test than in subjects with a negative result.

CONCLUSION

In conclusion, the serum vitamin D level was more likely to be critically low in patients with chronic urticaria, and an inverse relationship with disease severity and disease duration was observed. These findings may open up the possibility of the clinical use of vitamin D as a contributing factor in the pathogenesis of chronic urticaria and a predictive marker for disease activity in chronic urticaria.

Phloretin ameliorates chemokines and ICAM-1 expression via blocking of the NF-κB pathway in the TNF-α-induced HaCaT human keratinocytes

Previous studies found that phloretin had anti-oxidant, anti-inflammatory, and anti-tumor properties. In this study, we investigated whether phloretin could suppress the production of the intercellular adhesion molecule (ICAM)-1 and chemokines through downregulation of the nuclear transcription factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways in TNF-α-stimulated HaCaT human keratinocytes. HaCaT cells were treated with phloretin and then the cells were stimulated by TNF-α. Phloretin treatment decreased the production of IL-6, IL-8, CCL5, MDC, and TARC. Phloretin decreased ICAM-1 protein and mRNA expression, and also suppressed the adhesion of monocyte THP-1 cells to inflammatory HaCaT cells. Phloretin inhibited NF-κB translocation into the nucleus and also suppressed the phosphorylation of Akt and MAPK signal. In addition, phloretin increased heme oxygenase-1 production in a concentration-dependent manner. These results demonstrated that phloretin has anti-inflammatory effects to inhibit chemokines and ICAM-1 expressions through suppression of the NF-κB and MAPK pathways in human keratinocytes.

Pathogenesis of chronic urticaria: an overview

The pathogenesis of chronic urticaria is not well delineated and the treatment is palliative as it is not tied to the pathomechanism. The centrality of mast cells and their inappropriate activation and degranulation as the key pathophysiological event are well established. The triggering stimuli and the complexity of effector mechanisms remain speculative. Autoimmune origin of chronic urticaria, albeit controversial, is well documented. Numerical and behavioral alterations in basophils accompanied by changes in signaling molecule expression and function as well as aberrant activation of extrinsic pathway of coagulation are other alternative hypotheses. It is also probable that mast cells are involved in the pathogenesis through mechanisms that extend beyond high affinity IgE receptor stimulation. An increasing recognition of chronic urticaria as an immune mediated inflammatory disorder related to altered cytokine-chemokine network consequent to immune dysregulation resulting from disturbed innate immunity is emerging as yet another pathogenic explanation. It is likely that these different pathomechanisms are interlinked rather than independent cascades, acting either synergistically or sequentially to produce clinical expression of chronic urticaria. Insights into the complexities of pathogenesis may provide an impetus to develop safer, efficacious, and targeted immunomodulators and biological treatment for severe, refractory chronic urticaria.

Assessment of Interleukins IL-4, IL-6, IL-8, IL-10 in Acute Urticaria

Background

Urticaria is a skin disease that affects approximately 5% of the general population and manifests itself, not only as an acute but also as a chronic disease. The etiology of the disease varies as well as its clinical manifestations which extend from the presence of urticarial hives to the potentially mortal angioedema. There is a great interest to the disease not only due to its special clinical manifestation but also due to its pathogenetic mechanism. New data in the medical bibliography support the participation of interleukins (ILs) in the pathophysiology of urticaria. The aim of the study is to contribute in the comprehension of possible participation of certain ILs in the pathogenesis of acute urticaria.

Methods

Our study concerns four ILs, IL-4, IL-6, IL-8 and IL-10, simultaneously and their quantitative changes during the acute phase of urticaria as well as 2 weeks after drug administration. Moreover, ILs levels of patients were compared with those of matched healthy controls. All measurements have been done by the ELISA method. The statistical analysis was done by SPSS.

Results

The results present increased levels (in 51 patients vs. 22 matched healthy controls) of all four ILs during the acute phase. Especially for IL-4 this increase was statistically very significant (P < 0.001). Statistically marginally significant decrease was also observed for IL-10 concentrations (P < 0.059), for the two blood samples (acute phase and 2 weeks later).

Conclusion

It is suggested by the present study that certain ILs might play an important role in the pathogenetic mechanism of urticaria. IL-4 and IL-10 participation seems to be relatively more significant. Possibly, ILs, liberated by mast cells, induce an influx of leukocytes in the dermis, therefore participating in the development of acute urticaria inflammation.

CCL5/RANTES, sVCAM-1, and sICAM-1 in chronic spontaneous urticaria

BACKGROUND

Chronic urticaria (CU) is a common disease characterized by recurrent itchy wheals and/or angioedema for more than 6 weeks. We aimed to investigate the potential involvement of chemotactic mediators and soluble adhesion molecules as markers of endothelial dysfunction in the pathogenesis of chronic spontaneous urticaria (CSU). The potential relevance of these soluble mediators in the evaluation of disease activity was also investigated.

METHODS

We measured the levels of CCL5/RANTES, CXCL8/IL-8, sVCAM-1, and sICAM-1 in the sera of 87 patients with CSU and 61 normal healthy subjects (NHS) using ELISA assays. According to the results of autologous serum skin tests (ASST), CSU patients were classified into ASST-positive and ASST-negative subgroups. Furthermore, we investigated in 4 patients whether H₁-antihistamine therapy decreases sVCAM-1 and sICAM-1 levels.

RESULTS

We detected a significantly higher concentration of CCL5/RANTES (p < 0.0001) but not of CXCL8/IL-8 in CSU patients compared to NHS. The serum levels of sICAM-1 and sVCAM-1 were significantly increased in CSU patients compared to NHS (p = 0.0121 and p = 0.0043, respectively). No difference in chemokine or soluble adhesion molecule levels was detected between the ASST-positive and ASST-negative subgroups. A positive correlation was found between sICAM-1 and sVCAM-1 (p = 0.0022) but not between these and CCL5/RANTES. After H₁-antihistamine therapy, sVCAM-1 and sICAM-1 levels did not decrease in the 4 CSU patients tested.

CONCLUSIONS

Our study suggests that CCL5/RANTES, sICAM-1, and sVCAM-1 play a potential role in the pathogenesis of CSU but they do not parallel disease activity and are not predictive of the response to H₁-antihistamine therapy.

Chronic urticaria: Indian context-challenges and treatment options

Urticaria is a common condition that occurs in both children and adults. Most cases have no specific allergic trigger and the aetiology of urticaria remains idiopathic and occasionally spontaneous in nature. Inappropriate advice such as avoidance of foods (milk, egg, prawn, and brinjal) is common place in certain sections of India mostly by nonspecialists that should not be routinely recommended. It is important to look for physical urticarias such as pressure urticaria in chronic cases, which may be present either alone or in combination with other causes. Autoimmune causes for chronic urticaria have been found to play an important role in a significant proportion of patients. Long-acting nonsedating antihistamines at higher than the standard doses is safe and effective. Quality of life is affected adversely in patients with chronic symptomatic urticaria and some may require multidisciplinary management.

Trypanosoma cruzi SSP4 Amastigote Protein Induces Expression of Immunoregulatory and Immunosuppressive Molecules in Peripheral Blood Mononuclear Cells

The acute phase of Chagas' disease in mice and human is marked by states of immunosuppression, in which Trypanosoma cruzi replicates extensively and releases immunomodulatory molecules that delay parasite-specific responses mediated by effector T cells. This mechanism of evasion allows the parasite to spread in the host. Parasite molecules that regulate the host immune response during Chagas' disease have not been fully identified, particularly proteins of the amastigote stage. In this work, we evaluated the role of the GPI anchored SSP4 protein of T. cruzi as an immunomodulatory molecule in peripheral blood mononuclear cells (PBMCs). rMBP::SSP4 protein was able to stimulate nitric oxide (NO) production. Likewise, rMBP::SSP4 induced the expression of genes and production of molecules involved in the inflammatory process, such as, cytokines, chemokines, and adhesion molecules (CAMs) as determined by RT-PCR and ELISA. These results suggest that the amastigote SSP4 molecule could play a key role in the immunoregulatory and/or immunosuppressive process observed in the acute phase of infection with T. cruzi.