Yuichiro Tsunemi

Penicillium marneffei infection diagnosed by polymerase chain reaction from the skin specimen

We describe a case of Penicillium marneffei infection in a patient with AIDS who had skin eruptions disseminated over the entire surface of his skin. We identified P marneffei from the skin biopsy specimen by polymerase chain reaction using a set of primers specific for this pathogen.

Interleukin-12 p40 gene (IL12B) 3'-untranslated region polymorphism is associated with susceptibility to atopic dermatitis and psoriasis vulgaris.

Interleukin-12 (IL-12) is believed to play an important role in inducing Th1-type cytokine profiles. Atopic dermatitis (AD) and psoriasis vulgaris (PsV) are considered to be Th2 and Th1 type disease, respectively. The IL-12 p40 subunit gene (IL12B) is located at chromosome 5q31-33 and linkage findings of AD on 5q31 were reported. Recently single nucleotide polymorphism (SNP) (1188A/C) of IL12B has been reported. In function, it has been reported that this SNP is associated with IL12B mRNA expression levels. To learn whether this SNP is associated with susceptibility to AD or PsV, we investigated the genotype and allele frequencies of the SNP in AD patients, in PsV patients and in controls, examining 164 AD patients, 143 PsV patients and 100 healthy individuals in Japanese population. Genotyping was performed using the polymerase chain reaction-restriction fragment length polymorphism method. The A allele was decreased in AD patients (40.9%, p = 0.031) and increased in PsV patients (60.1%, p = 0.035) compared with controls (50.5%). This suggests that IL12B SNP is associated with susceptibility to AD and PsV, presumably by affecting the Th1/Th2 balance.

Significant elevation of serum levels of eotaxin-3/CCL26, but not of eotaxin-2/CCL24, in patients with atopic dermatitis: serum eotaxin-3/CCL26 levels reflect the disease activity of atopic dermatitis

Atopic dermatitis (AD) is a chronic and relapsing inflammatory skin disease characterized by the predominant infiltration of T cells, eosinophils and macrophages in lesional skin. Recently, eotaxin‐2/CCL24 and eotaxin‐3/CCL26 were identified as CC chemokines that signal exclusively via the CCR3 receptor and have eosinophil‐selective chemoattractant activity, as does eotaxin/CCL11. We previously reported that serum levels of thymus and activation‐regulated chemokine (TARC)/CCL17 and macrophage‐derived chemokine (MDC)/CCL22 were correlated with the severity of AD. In this report, we investigated the participation of eotaxin‐2/CCL24 and eotaxin‐3/CCL26 in AD, first measuring the serum levels of eotaxin‐2/CCL24 and eotaxin‐3/CCL26 in 30 patients with AD, 20 patients with psoriasis vulgaris and 20 healthy controls. The serum levels of eotaxin‐3/CCL26 (but not eotaxin‐2/CCL24) were significantly higher in patients with AD than in either healthy controls or patients with psoriasis vulgaris; furthermore, the eotaxin‐3/CCL26 levels in patients with moderate and severe AD were significantly higher than eotaxin‐3/CCL26 levels in patients with mild AD. The serum eotaxin‐3/CCL26 levels tended to decrease after treatment, but there was no significant difference between groups. Moreover, the serum eotaxin‐3/CCL26 levels were significantly correlated with the serum TARC/CCL17 and MDC/CCL22 levels, eosinophil numbers in peripheral blood and the scoring AD (SCORAD) index. Our study strongly suggests that serum levels of eotaxin‐3/CCL26, but not of eotaxin‐2/CCL24, have a notable correlation with disease activity of AD and that eotaxin‐3/CCL26, as well as TARC/CCL17 and MDC/CCL22, may be involved in the pathogenesis of AD.

Interleukin-13 gene polymorphism G4257A is associated with atopic dermatitis in Japanese patients

Interleukin (IL)-13 plays an important role in the induction of immunoglobulin E (IgE) and in the pathogenesis of atopic dermatitis (AD). We investigated the allele and genotype frequencies of three IL-13 single nucleotide polymorphisms (SNPs) (A704C and C1103T in the promoter region and G4257A in exon 4) in Japanese patients with AD. For A704C and C1103T SNPs, there were no significant differences in allele or genotype frequencies between AD patients and controls. For G4257A SNP, A allele was significantly increased in AD patients (39.5%) compared with controls (29.4%) (P = 0.016). The same proportion of each genotype and allele was observed in the patient subgroup with and without asthma. Serum IgE levels and peripheral eosinophil counts were not significantly different among genotypes in G4257A SNP. There was also no significant difference in allele or genotype frequencies between AD patients with mild disease and those with severe disease, between those with family history of AD and those without it, or between those with family history of atopic disorders and those without it. This result suggests that 4257A allele is associated with susceptibility to AD and that it may function in the pathogenesis of AD itself, presumably by other mechanisms than inducing IgE production.

Interleukin-4 and interleukin-13 enhance CCL26 production in a human keratinocyte cell line, HaCaT cells

Eotaxin‐2/CCL24 and eotaxin‐3/CCL26 are CC chemokines and their receptor, CC chemokine receptor 3 is preferentially expressed on eosinophils. It was reported that vascular endothelial cells and dermal fibroblasts produced CCL26. However, the regulation of CCL24 and CCL26 production in keratinocytes has not been well documented. We investigated the expression and production of CCL24 and CCL26 in the human keratinocyte cell line, HaCaT cells. Reverse transcription and polymerase chain reaction was performed using these cells and Enzyme‐linked immunosorbent assay was carried out using supernatant of these cells. The production of CCL24 in HaCaT cells was slightly enhanced by IL‐4 and that of CCL26 was strongly enhanced by IL‐4 and IL‐13. Furthermore, TNF‐α generated a synergistic effect on IL‐4 enhanced CCL26 production. Dexamethasone, IFN‐γ and the p38 mitogen‐activated protein kinase inhibitor SB202190 inhibited IL‐4 enhanced CCL26 production. IL‐4 enhanced production of CCL26 was inhibited by leflunomide and JAK inhibitor 1, but not by JAK3 inhibitor, which indicates that it is mediated by JAK1‐STAT6‐dependent pathway. This result also strongly suggests the involvement of the type 2 IL‐4 receptor in IL‐4 enhanced production of CCL26. These results suggest that keratinocytes are involved in the migration of CC chemokine receptor 3 positive cells such as eosinophils in a Th2‐dominant situation like atopic dermatitis.

Prevalence of atopic dermatitis in Japanese elementary schoolchildren

Background  Although there have been several reports on the prevalence of atopic dermatitis (AD) in Japanese schoolchildren based on questionnaires, there has been no nation‐wide study of the frequency of this condition diagnosed by dermatologists in regular health check‐ups of schoolchildren.

Prevalence of atopic dermatitis determined by clinical examination in Japanese adults

Dear Editor, Atopic dermatitis (AD) is an inflammatory skin disease that is characterized by pruritic and eczematous lesions persisting chronically. Studies on the prevalence of AD have produced widely varying figures which may be due to several factors such as subjects’ age, their community and the investigative methodology. There have been numerous studies on the prevalence of AD in children and adolescents, however, there have been few studies on AD in adults. Furthermore, most of these studies were based on hospital patient records or questionnaires. To the best of our knowledge, there has been no study of the prevalence of AD conducted by clinical examination in the general adult Japanese population. The objective of this study was to evaluate the prevalence of AD based on regular health check-ups by dermatologists in Japanese adults. The target population was government officials visiting the Health Service Center of Tokyo University for annual health check-ups in September 2004. Permission was obtained from the Board of the Health Service Center of Tokyo University. The government officials were told the purpose of the study, and those who granted consent participated in this study. AD was diagnosed by experienced dermatologists based on the Japanese Dermatological Association criteria for the disease. The severity of AD was graded as mild, moderate, severe or very severe according to the following criteria: (i) mild, skin involvement of mild eruption only; (ii) moderate, <10% surface area involvement of eruption with severe inflammation (severe eruption); (iii) severe, 710% but <30% skin involvement of severe eruption; and (iv) very severe, >70% of body involvement of severe eruption. The χ test was used to analyze the results, and P < 0.05 was considered statistically significant. A total of 2123 (1220 men and 903 women) officials were examined in this study. The average age was 38.8 ± 10.4 years (men: 39.6 ± 10.5; women: 37.7 ± 10.4) ranging 20–69 years. The prevalence of AD was 6.9% overall, and 9.8%, 8.7%, 4.4% and 2.6%, respectively, for those in their 20s, 30s, 40s and 50s/60s (Table 1). The prevalence of 30s was significantly higher than that of 40s (P < 0.0001). The prevalence of women was higher than that of men overall (9.3% vs 5.1%, P < 0.001), especially in 20s (13.1% vs 5.7%, P < 0.05) and 30s (11.5% 6.9%, P < 0.05). Table 2 depicts the severity of AD. Overall, 76.7%, 18.5%, 3.4% and 1.4% of those afflicted were in the mild, moderate, severe and very severe groups, respectively. There was no severe or very severe AD in those beyond their 40s, nor was there any very severe AD in men. This is the first study of the prevalence of AD determined by clinical examination in the general adult Japanese population. In 1999, Plunkett et al. reported the prevalence of AD based on clinical examination by dermatologists in adults in central Victoria, Australia. A total of 1457 people (670 men and 787 women) whose ages ranged 20–94 years were examined in their study. The prevalence of AD was 6.9% overall, and 5.7% and 8.1%, respectively, for men and women. There was a clear age-related variation: the prevalence was approximately 10%, 8%, 7%, 3%, 2%, respectively, for men in their 20s, 30s, 40s, 50s and 60s, and 22%, 13%, 7%, 7%, 2%, respectively, for women in their 20s, 30s, 40s, 50s and 60s. They classified AD into three categories: mild, moderate and severe. Of those with the disease, 82.8% were classified as being mild, 14.6% moderate, and 2.6% severe. Interestingly, their results and ours suggested the same tendency: (i) the overall prevalence of adult AD was approximately 7%; (ii) the prevalence of women was higher than that of men; (iii) the prevalence decreased with age; and (iv) approximately 80% of AD cases were in the mild group.

Polymorphisms of vitamin D receptor gene in Japanese patients with psoriasis vulgaris

We examined polymorphisms of vitamin D receptor (VDR) gene in Japanese patients with psoriasis vulgaris (PsV). We also studied the association between VDR gene polymorphisms and the response to vitamin D (VD) topical treatment in psoriatic patients. FokI, BsmI, ApaI and TaqI genotypes were determined by restriction fragment patterns in patients (n = 115) and controls (n = 69). In addition, 54 psoriatic patients were divided into two groups in terms of their response to VD (tacalcitol) topical treatment: non-responsive (n = 30) and responsive (n = 24) patients. The frequencies of B allele and t allele were lower in patients than in controls (9 vs. 19%: p < 0.01, 7 vs. 14%: p < 0.05, respectively). In regard to response to VD treatment, F allele was lower in non-responsive patients than in controls (47 vs. 64%, p < 0.05). We show that polymorphisms of VDR gene are associated with Japanese patients with PsV. Allelic variance in the VDR gene or other genes in linkage disequilibrium with this gene might predispose to the development of PsV.

Prevalent LIPH founder mutations lead to loss of P2Y5 activation ability of PA-PLA1α in autosomal recessive hypotrichosis†

Autosomal recessive hypotrichosis (ARH) is characterized by sparse hair on the scalp without other abnormalities. Three genes, DSG4, LIPH, and LPAR6 (P2RY5), have been reported to underlie ARH. We performed a mutation search for the three candidate genes in five independent Japanese ARH families and identified two LIPH mutations: c.736T>A (p.Cys246Ser) in all five families, and c.742C>A (p.His248Asn) in four of the five families. Out of 200 unrelated control alleles, we detected c.736T>A in three alleles and c.742C>A in one allele. Haplotype analysis revealed each of the two mutant alleles is derived from a respective founder. These results suggest the LIPH mutations are prevalent founder mutations for ARH in the Japanese population. LIPH encodes PA‐PLA1α (LIPH), a membrane‐associated phosphatidic acid‐preferring phospholipase A1α. Two residues, altered by these mutations, are conserved among PA‐PLA1α of diverse species. Cys246 forms intramolecular disulfide bonds on the lid domain, a crucial structure for substrate recognition, and His248 is one amino acid of the catalytic triad. Both p.Cys246Ser‐ and p.His248Asn‐PA‐PLA1α mutants showed complete abolition of hydrolytic activity and had no P2Y5 activation ability. These results suggest defective activation of P2Y5 due to reduced 2‐acyl lysophosphatidic acid production by the mutant PA‐PLA1α is involved in the pathogenesis of ARH. Hum Mutat 31:1–9, 2010.

CCL17 transgenic mice show an enhanced Th2-type response to both allergic and non-allergic stimuli.

CC chemokine ligand (CCL)17 is implicated in the pathogenesis of atopic dermatitis (AD). To study the effect of CCL17 produced by keratinocytes (KC) during inflammation, we created transgenic (Tg) mice in which CCL17 is overexpressed in KC. Th2‐type contact hypersensitivity (CHS) was enhanced and Th1‐type CHS was suppressed in these mice. Increased numbers of CC chemokine receptor (CCR)4+ cells and mast cells infiltrated in Tg mice. Levels of IL‐4 mRNA were higher and those of IFN‐γ mRNA were lower in both acute and chronic CHS. Higher levels of serum IgE were observed after CHS. Numbers of CCR4+ cells among PBMC were increased in Tg mice challenged acutely on the trunk. Chronic irritation with croton oil induced dermatitis and an elevation of serum IgE levels. Tg mice showed enhanced ear swelling after tape stripping. CCL17 was thought to modify the inflammation caused by sensitizing reagents as well as irritant reagents by attracting CCR4+ cells into the lesional skin and creating a Th2‐dominant condition. AD‐like conditions such as increased number of mast cells and elevated levels of serum IgE were observed. Thus, CCL17 may participate in the pathogenesis of skin diseases such as AD by regulating both allergic and irritant inflammation.