miR103a-3p in extracellular vesicles from FcεRI-aggregated human mast cells enhances IL-5 production by group 2 innate lymphoid cells.

BACKGROUND: Mast cells (MCs) are key regulators of IgE-mediated allergic inflammation. Cell-derived extracellular vesicles (EVs) contain bioactive compounds such as microRNAs. EVs can transfer signals to recipient cells, thus using a novel mechanism of cell-to-cell communication. However, whether MC-derived EVs are involved in FcεRI-mediated allergic inflammation is unclear. OBJECTIVE: We sought to investigate the effect of EVs derived from FcεRI-aggregated human MCs on the function of human group 2 innate lymphoid cells (ILC2s). METHODS: Human cultured MCs were sensitized with and without IgE for 1 hour and then incubated with anti-IgE antibody, IL-33, or medium alone for 24 hours. EVs in the MC supernatant were isolated by using ExoQuick-TC. RESULTS: Coculture of ILC2s with EVs derived from the FcεRI-aggregated MCs significantly enhanced IL-5 production and sustained upregulation of IL-5 mRNA expression in IL-33-stimulated ILC2s, but IL-13 production and IL-13 mRNA expression were unchanged. miR103a-3p expression was upregulated in IL-33-stimulated ILC2s that had been cocultured with EVs derived from anti-IgE antibody-stimulated MCs. Transduction of an miR103a-3p mimic to ILC2s significantly enhanced IL-5 production by IL-33-stimulated ILC2s. miR103a-3p promoted demethylation of an arginine residue of GATA3 by downregulating protein arginine methyltransferase 5 (PRMT5) mRNA. Reduction of protein arginine methyltransferase 5 expression in ILC2s by using a small interfering RNA technique resulted in upregulation of IL-5 production by IL-33-stimulated ILC2s. Furthermore, the level of miR103a-3p expression was significantly higher in EVs from sera of patients with atopic dermatitis than in EVs from nonatopic healthy control subjects. CONCLUSION: Eosinophilic allergic inflammation may be exacerbated owing to ILC2 activation by MC-derived miR103a-3p.

Serum level of hemokinin-1 is significantly lower in patients with chronic spontaneous urticaria than in healthy subjects.

BACKGROUND: We previously reported upregulation of expression of Mas-related G protein-coupled receptor X2 (MRGPRX2) on mast cells (MCs) in the skin of patients with severe chronic spontaneous urticaria (CSU). Serum levels of substance P (SP) were reportedly significantly elevated, in correlation with the severity of CSU. Hemokinin-1 (HK-1) reportedly induced histamine release from LAD2 cells via MRGPRX2. We aimed to investigate HK-1's role in CSU. METHODS: The concentrations of HK-1 and SP were measured using ELISAs. Skin- and synovium-derived cultured MCs were generated by culturing dispersed skin and synovial cells, respectively, with stem cell factor. MRGPRX2 expression in the MCs was reduced using a lentiviral shRNA silencing technique. RESULTS: Anti-SP Ab used in the SP ELISA showed 100% cross-reactivity to HK-1, but anti-HK-1 Ab showed 0% cross-reactivity to SP. The serum level of HK-1 was significantly lower in patients with CSU (n = 151) than in non-atopic healthy control (NC) subjects (n = 114). The EC50 of histamine release from MCs induced by HK-1 (5056 nM) was 12-fold higher than by SP (426 nM). Brief pretreatment of MCs with HK-1 at concentrations of 3.0-10 µM significantly reduced histamine release by 0.1 µM SP. However, brief incubation of MCs with HK-1 did not elicit rapid MRGPRX2 internalization. CONCLUSIONS: In NC subjects, high HK-1 concentrations may desensitize MGRPRX2-mediated MC activation, thereby preventing MC degranulation by SP.

Differentiation between control subjects and patients with chronic spontaneous urticaria based on the ability of anti-IgE autoantibodies (AAbs) to induce FcεRI crosslinking, as compared to anti-FcεRIα AAbs.

BACKGROUND: The reported prevalences of IgG autoantibodies (AAbs) to FcεRIα and IgE in sera from patients with chronic spontaneous urticaria (CSU) have varied, and these AAbs are also often observed in healthy control subjects. Regarding the histamine release activity of purified IgG from patients with CSU, the number of examined patients has been small. Thus, we sought to determine the prevalence and FcεRI crosslinking ability of these AAbs in a large number of patients with CSU and non-atopic control (NC) subjects. METHODS: We compared the concentrations of anti-IgE and anti-FcεRIα AAbs and the abilities of these AAbs to cause FcεRI aggregation in patients with CSU (n = 134) and NC subjects (n = 55) using ELISA and an in vitro elicitation test, respectively. RESULTS: The concentration of anti-IgE AAbs was significantly different between the NC subjects and the CSU patients (P < 0.0001, cutoff value: 0.558 µg/mL), whereas the concentration of anti-FcεRIα AAbs was not. A significant difference in the duration of illness was noted between patients with lower and those with higher concentrations of anti-IgE AAbs relative to the cutoff value. The abilities of anti-IgE AAbs, but not anti-FcεRIα AAbs, to induce FcεRI crosslinking were significantly higher in CSU patients than in NC subjects (P = 0.0106). CONCLUSIONS: In the Japanese population of CSU patients studied, the ability of the anti-IgE AAbs to induce FcεRI crosslinking differed significantly between NC subjects and CSU patients, suggesting the involvement of anti-IgE AAbs in the pathogenesis of CSU in the Japanese population.

Quantitative Analysis of Formaldehyde-induced Fluorescence in Paraffin-embedded Specimens of Malignant Melanomas and Other Melanocytic Lesions.

Inter-observer agreement is problematic in the histopathological diagnosis of melanoma and melanocytic naevi, even among expert pathologists. Formaldehyde-induced fluorescence (FIF) has been used for histochemical demonstration of catecholamines, 5-hydroxytryptamine and their immediate precursors. FIF can detect melanogenic activity and may be useful in differentiating malignant melanoma from other melanocytic lesions. The fluorescence of various types of melanocytic lesions has been previously studied quantitatively in formalin-fixed and paraffin-embedded sections. This study compared 2 sets of excitation and emission bands: 450-490 nm excitation/510-560 nm absorption filters (filter unit A) and 480 nm excitation/510< nm absorption filters (filter unit B). Higher FIF was observed with filter unit A than with filter unit B. FIF intensity of central regions was found to be higher than that of the peripheral regions. Mean FIF was significantly higher in malignant melanomas than in naevi. Fluorescence imaging with filter unit A gave better diagnostic performance. In conclusion, quantitative measurement of FIF is a useful marker of malignant potential.

Treatment of murine mast cells with IgEκ and protein L enhances apoptotic cell death induced by IL-3 withdrawal.

Engagement of the high-affinity IgE receptor (FcεRI) can be either protective or non-protective against apoptotic cell death (ACD) in bone marrow-derived murine mast cells (BMMCs) after IL-3 withdrawal, depending on the avidity between IgE and its antigen. We recently reported that protein L (PpL), a bacterial Igκ-binding soluble protein, is able to stimulate intracellular signaling to induce activation of BMMCs by interacting with the IgEκ-FcεRI complex. However, it is unclear if cross-linking of FcεRI with IgEκ and PpL prevents or enhances IL-3-dependent ACD in BMMCs. In the present study, we found that IL-3-dependent ACD of BMMCs is accelerated by loading soluble PpL in the presence of IgEκ-occupied FcεRIα. For this purpose, soluble PpL was incorporated into the BMMCs. Unlike soluble PpL, immobilized PpL failed to enhance ACD, although both forms of PpL induced IL-6 production equally in BMMCs. In addition, we observed that DNS5-BSA protected anti-DNS IgE-sensitized BMMCs from IL-3 depletion-mediated ACD by inducing the production of autocrine IL-3. In contrast, DNS5-PpL enhanced IL-3 withdrawal-induced ACD of anti-DNS IgE-sensitized BMMCs and reduced the production of autocrine IL-3. These findings suggest that PpL increases IL-3 withdrawal-induced ACD of IgEκ-sensitized BMMCs by incorporating PpL into the BMMCs and that this internalized PpL may interfere with survival signals via FcεRI.

The oncogenic role of GASC1 in chemically induced mouse skin cancer.

Gene amplified in squamous cell carcinoma (SCC) 1 (GASC1), also known as KDM4C/JMJD2C, encodes a histone demethylase that specifically demethylates lysine residues (H3K9, H3K36, and H1.4K26) and plays a crucial role in the regulation of gene expression as well as in heterochromatin formation. GASC1 is located at human chromosome 9p23-24, where frequent genomic amplification is observed in human esophageal cancer, and its aberrant expression is detected in a variety of human cancers, such as breast, colon, and prostate. Therefore, it is highly likely that GASC1 contributes to the genesis and/or development of cancer. However, there is a lack of direct evidence of GASC1 having an oncogenic function. In this study, we aimed to clarify the role of GASC1 in the skin SCC carcinogenesis. For this purpose, we generated Gasc1-heterozygous mice (Gasc1+/-) with reduced expression of Gasc1. On the basis of our results, Gasc1+/- mice displayed a significantly lower incidence and multiplicity of both benign and malignant tumors induced by the two-stage skin carcinogenesis protocol than wild-type mice. In addition, the volume of carcinoma was significantly lower in Gasc1+/- mice. Consistent with these observations, knocking down of Gasc1 resulted in reduced cell viability of SCC cells in vitro. Our findings clearly demonstrated that GASC1 has an oncogenic role in skin carcinogenesis.

FcRγ promotes contact hypersensitivity to oxazolone without affecting the contact sensitisation process in B6 mice.

The process of sensitisation by specific contact allergens is indispensable for the induction of allergic contact dermatitis. Oxazolone is a well-characterised contact allergen. Previous studies suggested that immune cells bearing the FcRγ subunit are essential for oxazolone-induced contact hypersensitivity, but the biological functions of the FcRγ subunit in the process of sensitisation to oxazolone remain unknown. In this study, we show that FcRγ deficiency decreases ear-swelling responses to oxazolone in mice. However, we found that oxazolone-sensitised FcRγ(-/-) mice and oxazolone-sensitised wild-type (WT) mice have comparable numbers of CD11c(+) MHCII(hi) dendritic cells (DCs) in their draining lymph nodes (LNs). In addition, oxazolone-sensitised LN cells from both FcRγ(-/-) and WT mice showed considerable production of interferon-gamma (IFNγ), interleukin-4 (IL-4) and IL-17A upon oxazolone-keyhole limpet haemocyanin loading. Consistent with these data, oxazolone-sensitised FcRγ(-/-) and FcRγ(+/+) LN cells conferred contact hypersensitivity to WT naïve mice challenged with the hapten. Our findings clearly indicate that, in an experimental mouse model, the FcRγ subunit positively regulates contact hypersensitivity to oxazolone without affecting the contact sensitisation process.

Effectiveness of a heparinoid-containing moisturiser to treat senile xerosis.

BACKGROUND AND OBJECTIVES: With the increasing elderly population in Japan, skin problems have become a greater concern. A heparinoid-containing moisturiser is frequently used in Japan, but there is a lack of evidence for its efficacy in treating senile xerosis. To determine whether there is a correlation between age and the hydration state of the stratum corneum (SC) assessed by skin capacitance, and to evaluate the efficiency of a heparinoid-containing moisturiser and a bed bath to treat senile xerosis. METHODS: We recruited 73 individuals to assess the hydration state of the SC on their flexor forearm by measuring their skin capacitance. To evaluate the efficacy of a heparinoid-containing moisturiser on senile xerosis, we recruited seven inpatients with an inactive daily life (IDL) who had senile xerosis. They were treated with the moisturiser in addition to a bed bath in two different protocols, and we measured the skin capacitance on their flexor forearms on days 0, 7 and 14. RESULTS: There was a weak negative correlation (-0.3854, P < 0.01) between skin capacitance and age. Following the moisturiser treatments, the seven inpatients had increased hydration of both arms on days 7 and 14. The skin capacitance of the right forearm slightly decreased on day 14, even though it was significantly different from day 0 (P < 0.05). CONCLUSIONS: These findings indicate that treatment with a heparinoid-containing moisturiser together with a bed bath is an effective method for treating patients who have senile xerosis and IDL.

Expression of Mas-related gene X2 on mast cells is upregulated in the skin of patients with severe chronic urticaria.

BACKGROUND: Wheal reactions to intradermally injected neuropeptides, such as substance P (SP) and vasoactive intestinal peptide, are significantly larger and longer lasting in patients with chronic urticaria (CU) than in nonatopic control (NC) subjects. Mas-related gene X2 (MrgX2) has been identified as a receptor for basic neuropeptides, such as SP and vasoactive intestinal peptide. Mast cell (MC) responsiveness to eosinophil mediators contributes to the late-phase reaction of allergy. OBJECTIVE: We sought to compare the frequency of MrgX2 expression in skin MCs from patients with CU and NC subjects and to identify the receptor for basic eosinophil granule proteins on human skin MCs. METHODS: MrgX2 expression was investigated by using immunofluorescence in skin tissues from NC subjects and patients with severe CU and on skin-derived cultured MCs. MrgX2 expression in human MCs was reduced by using a lentiviral small hairpin RNA silencing technique. Ca(2+) influx was measured in CHO cells transfected with MrgX2 in response to eosinophil granule proteins. Histamine and prostaglandin D2 levels were measured by using enzyme immunoassays. RESULTS: The number of MrgX2(+) skin MCs and the percentage of MrgX2(+) MCs in all MCs in patients with CU were significantly greater than those in NC subjects. Eosinophil infiltration in urticarial lesions was observed in 7 of 9 patients with CU. SP, major basic protein, and eosinophil peroxidase, but not eosinophil-derived neurotoxin, induced histamine release from human skin MCs through MrgX2. CONCLUSION: MrgX2 might be a new target molecule for the treatment of wheal reactions in patients with severe CU.

Activation of LXRs using the synthetic agonist GW3965 represses the production of pro-inflammatory cytokines by murine mast cells.

BACKGROUND: The activation of liver X receptor (LXR) α or LXRß negatively regulates the expression of pro-inflammatory genes in mammalian cells. We recently reported that 25-hydroxycholesterol, a representative LXR-activating oxysterol, suppresses IL-6 production in mouse mast cells (MCs) following its engagement of the high-affinity IgE receptor (FcεRI). This finding suggests that murine MCs express functional LXRs; however, the mechanisms underlying the LXR-dependent repression of the MC-mediated production of pro-inflammatory cytokines, including IL-6, are poorly understood. Therefore, we employed the synthetic LXR ligand GW3965 to examine the functions of LXRα and LXRß in the production of pro-inflammatory cytokines by murine bone marrow-derived MCs (BMMCs). METHODS: We prepared BMMCs from wild-type (WT), LXRα(-/-), and LXRα/ß(-/-) mice. Each group of BMMCs was pretreated with GW3965 and then stimulated with IgE+antigen (Ag) or lipopolysaccharide (LPS). Cytokine production was then analyzed using specific ELISA kits. RESULTS: The activation of LXRs by GW3965 significantly attenuated the production of IL-1α and IL-1ß, but not of IL-6, in the WT and LXRα(-/-) BMMCs stimulated with IgE+Ag. However, GW3965 treatment decreased the production of IL-1α, IL-1ß, and IL-6 in WT and LXRα(-/-) BMMCs upon stimulation with LPS, while the GW3965-mediated suppression of cytokine production was nearly absent from the LXRα/ß(-/-) BMMCs. CONCLUSIONS: These findings demonstrate, for the first time, that the activation of LXRs by GW3965 attenuates the antigen- or LPS-induced production of pro-inflammatory cytokines, such as IL-1α and IL-1ß, in murine MCs and that LXRß plays an important role in the LXR-mediated repression of cytokine production.

Efficacy and Safety of Brodalumab, an Anti-interleukin-17 Receptor A Monoclonal Antibody, for Palmoplantar Pustulosis: 16-Week Results of a Randomized Clinical Trial.

BACKGROUND: Palmoplantar pustulosis (PPP), a refractory skin disease characterized by repeated eruptions of sterile pustules and vesicles on palms and/or soles, involves interleukin-17 pathway activation. Brodalumab, a fully human anti-interleukin-17 receptor A monoclonal antibody, is being investigated for use in PPP treatment. OBJECTIVE: The aim was to assess the efficacy and safety of brodalumab in Japanese PPP patients with moderate or severe pustules/vesicles. METHODS: A phase 3, randomized, double-blind, placebo-controlled trial was conducted between July 2019 and August 2022, at 41 centers in Japan. Patients aged 18-70 years with a diagnosis of PPP for ≥ 24 weeks, a PPP Area Severity Index (PPPASI) score of ≥ 12, a PPPASI subscore of pustules/vesicles of ≥ 2, and inadequate response to therapy were included. Participants were randomized 1:1 to receive brodalumab 210 mg or placebo, subcutaneously (SC) at baseline, weeks 1 and 2, and every 2 weeks (Q2W) thereafter until week 16. Changes from baseline to week 16 in the PPPASI total score (primary endpoint) and other secondary skin-related endpoints and safety endpoints were assessed. RESULTS: Of the 126 randomized patients, 50 of 63 in the brodalumab group and 62 of 63 in the placebo group completed the 16-week period. Reasons for discontinuation were adverse event (n = 6), withdrawal by patient/parent/guardian (n = 3), progressive disease (n = 3), and lost to follow-up (n = 1) in the brodalumab group and Good Clinical Practice deviation (n = 1) in the placebo group. Change from baseline in the PPPASI total score at week 16 was significantly higher (p = 0.0049) with brodalumab (least-squares mean [95% confidence interval {CI}] 13.73 [10.91-16.56]) versus placebo (8.45 [5.76-11.13]; difference [95% CI] 5.29 [1.64-8.94]). At week 16, brodalumab showed a trend of rapid improvement versus placebo for PPPASI-50/75/90 response (≥ 50%/75%/90% improvement from baseline) and Physician's Global Assessment 0/1 score: 54% versus 24.2%, 36.0% versus 8.1%, 16.0% versus 0.0%, and 32.0% versus 9.7%, respectively. Infection was the dominant treatment-emergent adverse event (TEAE); the commonly reported TEAEs were otitis externa (25.4%/1.6%), folliculitis (15.9%/3.2%), nasopharyngitis (14.3%/4.8%), and eczema (14.3%/12.9%) in the brodalumab/placebo groups, respectively. The severity of most TEAEs reported was Grade 1 or 2 and less frequently Grade ≥ 3. CONCLUSIONS: Brodalumab SC 210 mg Q2W demonstrated efficacy in Japanese PPP patients. The most common TEAEs were mild infectious events. TRIAL REGISTRATION: NCT04061252 (Date of Trial Registration: August 19, 2019).

Exploratory Efficacy Evaluation of Apremilast for the Treatment of Japanese Patients with Palmoplantar Pustulosis: 32-Week Results from a Phase 2, Randomized, Placebo-Controlled Study.

INTRODUCTION: Palmoplantar pustulosis (PPP) is a pruritic, painful, chronic dermatitis that greatly impacts functioning and quality of life and can be difficult to treat. Approved treatment options for PPP are limited, and many patients do not fully respond to current treatments. METHODS: This was a randomized, double-blind, placebo-controlled, phase 2 study in Japanese patients with moderate to severe PPP and inadequate response to topical treatment. Patients were randomized 1:1 to receive apremilast 30 mg twice daily or placebo for 16 weeks followed by an extension phase where all patients received apremilast through week 32. PPP Area and Severity Index (PPPASI), modified PPPASI (which evaluates pustules and vesicles separately), and Palmoplantar Severity Index (PPSI) total scores and subscores (erythema, pustules/vesicles, and desquamation/scales) were evaluated over 32 weeks of apremilast treatment. Achievement of ≥ 50% improvement in PPPASI (PPPASI-50) was evaluated at week 16 among baseline demographic and clinical characteristic subgroups. RESULTS: At week 16, improvements in total score and subscores for PPPASI, modified PPASI, and PPSI, as well as rates of PPPASI-50 were at least moderately greater with apremilast than placebo. Mean PPPASI total score decreased by - 68.3% from baseline to week 32 with continued apremilast treatment. At week 32, mean change from baseline in PPPASI/modified PPPASI subscores ranged from - 58.5% to - 77.0% with apremilast. At week 32, PPSI total score for physician and patient assessments decreased by - 51.3% and - 40.0%, respectively, with continued apremilast treatment. PPPASI-50 response at week 16 was greater with apremilast versus placebo in most demographic and baseline characteristic subgroups. CONCLUSIONS: Improvements in all PPPASI and PPSI total scores and subscores observed with apremilast over 16 weeks were maintained through 32 weeks in patients with moderate to severe PPP and inadequate response to topical treatment. Rates of PPPASI-50 response at week 16 were mostly consistent across patient subgroups. CLINICALTRIALS: GOV: NCT04057937.

International Consensus Definition and Diagnostic Criteria for Generalized Pustular Psoriasis From the International Psoriasis Council.

Importance: Generalized pustular psoriasis (GPP) lacks internationally accepted definitions and diagnostic criteria, impeding timely diagnosis and treatment and hindering cross-regional clinical and epidemiological study comparisons. Objective: To develop an international consensus definition and diagnostic criteria for GPP using the modified Delphi method. Evidence Review: The rarity of GPP presents a challenge in acquiring comprehensive published clinical data necessary for developing standardized definition and criteria. Instead of relying on a literature search, 43 statements that comprehensively addressed the fundamental aspects of the definitions and diagnostic criteria for GPP were formulated based on expert reviews of 64 challenging GPP cases. These statements were presented to a panel of 33 global GPP experts for voting, discussion, and refinements in 2 virtual consensus meetings. Consensus during voting was defined as at least 80% agreement; the definition and diagnostic criteria were accepted by all panelists after voting and in-depth discussion. Findings: In the first and second modified Delphi round, 30 (91%) and 25 (76%) experts participated. In the initial Delphi round, consensus was achieved for 53% of the statements, leading to the approval of 23 statements that were utilized to develop the proposed definitions and diagnostic criteria for GPP. During the second Delphi round, the final definition established was, "Generalized Pustular Psoriasis is a systemic inflammatory disease characterized by cutaneous erythema and macroscopically visible sterile pustules." It can occur with or without systemic symptoms, other psoriasis types, and laboratory abnormalities. GPP may manifest as an acute form with widespread pustules or a subacute variant with an annular phenotype. The identified essential criterion was, "Macroscopically visible sterile pustules on erythematous base and not restricted to the acral region or within psoriatic plaques." Conclusions and Relevance: The achievement of international consensus on the definition and diagnostic criteria for GPP underscores the importance of collaboration, innovative methodology, and expert engagement to address rare diseases. Although further validation is needed, these criteria can serve as a reference point for clinicians, researchers, and patients, which may contribute to more accurate diagnosis and improved management of GPP.

IL12B and IL23R gene SNPs in Japanese psoriasis.

Psoriasis is a common human skin disease whereby abnormal production of inflammatory mediators is believed to play an important role in its pathogenesis. The IL12B gene, which encodes the shared IL-12p40 subunit in two cytokines, IL-12 and IL-23, and the IL23R gene, which encodes a subunit of the receptor for IL-23, were identified as psoriasis-susceptibility genetic factors in recent candidate gene and genome-wide association studies of Chinese and Europeans. Since there are significant differences in the incidence of psoriasis between Europeans and Japanese suggesting a genetic ethnic effect, we examined the association of IL12B and IL23R gene polymorphisms with psoriasis in a cohort of Japanese. In this study, we genotyped two SNPs (rs3212227 and rs6887695) in the IL12B gene and one SNP (rs11209026) in the IL23R gene using 560 Japanese psoriasis cases and 560 controls and compared our results with those previously published for Europeans and Asians. Our study showed significant associations between psoriasis and both IL12B gene SNPs, rs3212227 (odds ratio (OR) = 1.35, P = 4.94E-04) and rs6887695 (OR = 1.32, P = 2.00E-03), but no significant association between psoriasis and the IL23R SNP, rs11209026. Furthermore, a significant haplotype association was found for the IL12B gene protective haplotype C-C (OR = 0.71, P = 1.84E-04) in Japanese, as previously elucidated in the studies of European ancestry.

Significantly high levels of anti-dsDNA immunoglobulin E in sera and the ability of dsDNA to induce the degranulation of basophils from chronic urticaria patients.

BACKGROUND: Chronic urticaria (CU) appears to be of autoimmune origin in about half of all patients, since several autoreactive immunoglobulin Gs (IgGs), such as anti-FcεRIα and anti-IgE, are detected in the sera of such patients. However, whether autoreactive IgE is associated with CU remains unclear. In this study, we attempted to identify autoreactive IgE antibodies in sera from patients with CU. METHODS: Sera were collected from 67 normal subjects, 85 patients with CU and 28 patients with atopic dermatitis (AD). An autologous serum skin test (ASST) was performed on 27 of the CU patients. Autoreactive IgE and IgG levels against self-antigens were measured using enzyme-linked immunosorbent assays. The basophils were activated with dsDNA, and the CD63 expression level was examined using a fluorescence-activated cell sorter. RESULTS: The anti-dsDNA IgE levels were significantly higher in patients with CU and AD than in normal subjects, but no differences in the anti-dsDNA IgG levels were seen. The levels of thioredoxin-, peroxiredoxin- and thyroglobulin-reactive IgE and IgG were not significantly higher in the CU patients than in the other 2 groups. There was no significant difference in the levels of anti-dsDNA IgE between ASST-positive and ASST-negative patients. The basophils from 2 out of 9 CU patients exhibited degranulation in response to dsDNA. CONCLUSIONS: Our data suggest that anti-dsDNA IgE is involved in the pathogenesis of some cases of CU.