Association of SPINK5 gene polymorphisms with atopic dermatitis in the Japanese population

BACKGROUND: Netherton's syndrome (NS) is an autosomal recessive disorder characterized by trichorrhexis invaginata ('bamboo hair'), congenital ichthyosiform erythroderma and an atopic diathesis. NS has recently been shown to be due to a defect in the SPINK5 gene, encoding LEKTI, a 15-domain serine protease inhibitor. SPINK5 maps to chromosome 5q31-q32, and has been suggested to be a locus predisposing to atopy in general. Recently, coding polymorphisms in SPINK5 exons 13 and 14 have been reported to be associated with atopy, asthma and atopic dermatitis (AD). OBJECTIVES: To examine whether these polymorphisms are also associated with AD in Japan. METHODS: We characterized eight polymorphisms in SPINK5 exons 13 and 14 in 124 Japanese patients with AD and 110 healthy controls. The polymorphisms we examined were IVS12-26C-->T, IVS12-10A-->G, 1103A-->G (Asn368Ser, in exon 13), 1156G-->A (Asp386Asn, in exon 13), 1188T-->C (His396His, in exon 13), IVS13-50G-->A, 1258G-->A (Glu420Lys, in exon 14) and IVS14+19G-->A. RESULTS: We found significant associations between seven of these polymorphisms and AD in Japanese patients. CONCLUSIONS: This study confirms the previous suggestion of an association between SPINK5 and AD.     

A heterozygous null mutation combined with the G1258A polymorphism of SPINK5 causes impaired LEKTI function and abnormal expression of skin barrier proteins

Background  Loss-of-function mutations in the Kazal-type serine protease inhibitor, LEKTI, encoded by the SPINK5 gene cause the rare autosomal recessive skin disease Netherton syndrome (NS). G1258A polymorphism in SPINK5 may be associated with atopic dermatitis, which shares several clinical features with NS.
Objectives  To determine if the phenotype of NS can be caused by a single null mutation in SPINK5 combined with the homozygous G1258A polymorphism.
Methods  We screened mutations in the gene SPINK5 by direct DNA sequencing and position cloning and examined the expressions of the SPINK5 -encoded protein LEKTI and other relevant proteins by immunostaining and immunoblot.
Results  We describe here a patient who was clinically diagnosed with NS and carried a single null mutation in SPINK5 combined with the homozygous G1258A polymorphism. SPINK5 mRNA was present at normal levels and LEKTI was expressed in the epidermis. Nonetheless, the putative downstream LEKTI substrates stratum corneum trypsin-like enzyme (SCTE), desmoglein 1 and protein markers of keratinocyte differentiation were expressed abnormally, similar to that seen in NS if two null mutant alleles are present.
Conclusion  This finding indicates that haploinsufficiency of SPINK5 can cause the NS phenotype in the presence of one null mutation with homozygous G1258A polymorphisms in SPINK5 , and this could impair the function of LEKTI and therefore acts as a true mutation.     

Influence of endothelial nitric oxide synthase polymorphisms in psoriasis risk

Nitric oxide (NO) is a potent regulator of keratinocyte growth and differentiation that has been implicated in the pathogenesis of psoriasis (Ps). The NOS3 −786 T/C (SNP id rs2070744; ), intron 4 variable number tandem repeat (VNTR), and Glu298Asp (SNP id rs1799983) polymorphisms, have been associated with differences in NO plasma concentrations and with the risk of hypertension (HT) and ischemic cardiac disease. The aim of this study was to determine whether the above-mentioned NOS3 variants contributed to the risk of Ps, and were associated with the risk for HT and CAD in these patients. A total of 368 patients with chronic plaque Ps and 400 healthy controls were genotyped for the NOS3 −786 T/C, intron 4 VNTR, and Glu298Asp polymorphisms. Carriers of the −786 C allele were significantly more frequent among the patients (p < 0.001). Carriers of the 4-repeats allele (45 + 44 genotypes) were also more frequent a (p < 0.001). No significant difference was found for the Glu298Asp polymorphism. None of the NOS3 variants was associated with Ht and CAD in our population. In conclusion, NOS3 gene polymorphism would be risk factors for developing Ps.     

Netherton syndrome: mutation analysis of two Taiwanese families

Netherton syndrome (NS) is a severe autosomal recessive skin disorder characterized by congenital ichthyosiform erythroderma, hair shaft abnormalities, and atopic diathesis. Recently, pathogenic mutations were identified in serine protease inhibitor Kazal-type 5 (SPINK5), the gene that encodes lympho-epithelial Kazal-type related inhibitor (LEKTI), a type of serine protease inhibitor involved in the regulation of skin barrier formation and immunity. In the present report, we describe the mutation analysis of two Taiwanese patients with NS. Patient 1 has heterozygous mutations; the maternal allele has novel T808I (C–T transition in codon 808) and the paternal allele has recurrent R790X (C–T transition in codon 790). Patient 2 is homozygous for a novel polymorphism R267Q (G–A transition in codon 267). The change was not detected in the patient’s father. Haplotype analysis revealed that the patient was homozygous for the 5 single nucleotide polymorphisms in the genomic sequence of SPINK5 as well as the flanking (GT)₁₇ and D5S413, in addition to the discrepancy of R267Q. Nevertheless real-time quantitative PCR analysis revealed no microdeletion in the genomic sequence of SPINK5. Thus uniparental disomy of maternal SPINK5 allele was indicated. Shuan-Pei Lin and Shu-Yi Huang contributed equally to this work.     

Distinct SPINK5 and IL-31 polymorphisms are associated with atopic eczema and non-atopic hand dermatitis in Taiwanese nursing population

Abstract: The term ‘hand dermatitis’ describes inflammatory skin condition localized to the hands. Nurses working at hospital settings are prone to develop hand dermatitis. The current study aimed to evaluate whether certain genetic polymorphisms were associated with the development of atopic eczema or non‐atopic hand dermatitis in Taiwanese population. Nurses of Kaohsiung Medical University Hospital were recruited. Atopic eczema, non‐atopic hand dermatitis and normal control groups were identified. The serine protease inhibitor Kazal type 5 (SPINK5), filaggrin and interleukin‐31 (IL‐31) gene variants were compared between the diseased and control groups. Our results showed that rs2303070 T allele of SPINK5 (assuming recessive model; OR = 3.58, 95% CI 1.63–7.84; P = 0.0014) and rs7977932 G allele of IL‐31 (assuming recessive model; OR = 18.25, 95% CI = 3.27–101.94; P = 0.0009) were associated with increased risks of developing atopic eczema, while rs6892205 G allele of SPINK5 (assuming dominant model; OR = 3.79, 95% CI 1.55–9.28; P = 0.0036) was associated with the development of non‐atopic hand dermatitis. In summary, our results showed that distinct SPINK5 and IL‐31 gene variants were associated with the development of atopic eczema and non‐atopic hand dermatitis. The barrier function, particularly those regulated by SPINK5, may play an important role in the development of both atopic eczema and non‐atopic hand dermatitis.     

Influence of functional variants Asp312Asn and Lys751Gln of Xeroderma Pigmentosum Group D (XPD) and Glutathione S‐transferase Mu 1 (GSTM1) and Theta 1 (GSTT1) genes on cutaneous melanoma susceptibility and prognosis

We aimed to evaluate whether variants in repair (XPD Asp312Asn, XPD Lys751Gln) and detoxification (GSTM1, GSTT1) genes alter risk, clinicopathological aspects and survival of cutaneous melanoma (CM). Genotyping was performed in 229 CM patients and 258 controls. Individuals with XPD 312Asp/Asn or Asn/Asn plus GSTT1 null genotype were under 2.00 (95% CI: 1.06‐3.79), and XPD 312Asn/Gln haplotype was under 1.44‐fold (95% CI: 0.99‐2.08) increased risks to CM than others. Individuals with GSTM1 plus GSTT1 null genotype had 9.61‐fold (95% CI: 2.28‐40.38) increased risk of metastatic CM. At 60 months of follow‐up, patients with XPD 751Gln/Gln plus GSTT1 null and GSTM1 null plus GSTT1 null genotype presented 7.36 and 3.05 more chances of evolving to death in multivariate Cox analysis, respectively. In conclusion, our data indicate, for the first time, that specific variant combinations of XPD, GSTM1 and GSTT1 may increase susceptibility to CM and influence patients’ clinicopathological features and survival.     

Two cases of reactive perforating collagenosis arising at the site of healed herpes zoster.

Case 1 A 67‐year‐old South Korean woman presented with a painful eruption on the left trunk. Several groups of vesicles with an erythematous and edematous base were situated unilaterally within the distribution of the left T9 dermatome; they had been present for 7 days. A diagnosis of herpes zoster was made, and treatment with acyclovir, analgesics, tranquilizers, and wet dressings produced a moderate response. Two weeks after onset, the lesions appeared to have healed with a scar. Four months later, however, the patient noticed another eruption of papules in the postherpetic area ( Fig. 1A,B ).

Figure 1 Open in figure viewer PowerPoint Case 1. (A) Multiple erythematous papules on the left trunk along the T9 dermatome. (B) Multiple erythematous papules with a keratotic central plug     

ASSESSMENT OF MC1R AND α-MSH GENE SEQUENCES IN IRANIAN VITILIGO PATIENTS

Background:

Vitiligo is an acquired pigmentary disorder of the skin that is caused by unknown factors and is characterized by white and depigmented patches that enlarge and become more numerous with time. Genetic factors, oxidative stress, autoimmunity, and neurochemical agents, such as catecholamines might also contribute to vitiligo. Cutaneous pigmentation is determined by the amounts of eumelanin and pheomelanin synthesized by the epidermal melanocytes and interference of melanocortin-1 receptor (MC1R), a G-protein coupled receptor, its normal agonist, alpha-melanocyte stimulating hormone (α-MSH), and key enzymes, such as tyrosinase, to protect against sun-induced DNA damage. The MC1R, a 7 pass trans-membrane G-protein coupled receptor, is a key control point in melanogenesis. Loss-of-function mutations at the MC1R are associated with a switch from eumelanin to pheomelanin production, resulting in a red or yellow coat color.

Aim:

In this research, we aim to examine the genetic variety of MC1R and α-MSH gene in 20 Iranian vitiligo patients and 20 healthy controls.

Materials and Methods:

Analysis of the MC1R coding gene was performed with direct sequencing.

Results:

We found the following 9 MC1R coding region variants: Arg163Gl (G488A), Arg227Leu (G680A), Val 97Phe (G289T), Asp184Asn (G550A), Arg227Lys (G680A), Arg142His (G425A), Val60Leu (G178T), Val247Met (C739A), and Val174Ile (G520A). We also found 2 frameshift changes: one of them was the Insertion of C (frameshift in Pro136, stop at Trp148) and the other, Insertion of G (frameshift in Pro256, stop at Trp 333). Of all the changes, the most common was Val60Leu at 5% in patients vs 20% in controls, Val247Met at 15% in patients vs 0% in controls and Val174Ile at 15% in controls and 0% in patients. The other variants showed a frequency <5% in both patients and controls. Also in this study, we have examined the frequency of single nucleotide polymorphisms within the α-MSH genes with direct sequencing in 20 patients and 20 healthy subjects but found no changes along this gene.

Conclusion:

We could not find any relationship between MC1R and α-MSH genes and their effect on the disease in Iranian vitiligo patients.     

Combined occurrence of filaggrin mutations and IL-10 or IL-13 polymorphisms predisposes to atopic dermatitis

Background: Although filaggrin mutations are presently believed to play a key role in the development of atopic dermatitis (AD), obviously also immunological factors involved in acquired immune response are important for the development of allergic inflammation. Objective: To assess the frequency of FLG mutations and the polymorphisms 590 C/T in the IL‐4 gene, ‐1082A/G in the IL‐10 gene and ‐1055C/T in the IL‐13 gene in patients with AD and their correlations between severity of AD and asthma. Methods: R501X and 2282del4 FLG mutations and IL‐4, IL‐10 and IL‐13 polymorphisms were assayed in 163 patients with AD of Polish origin. Results: In the Polish patients with AD, the prevalence of FLG mutations was higher in patients with AD than in the controls and 2282del4 FLG mutation was more frequent than R501X, and it was associated with a 6‐fold higher risk for AD development (P < 0.001; OR: 5.76), moderate or severe disease course, early onset of asthma and palmar hyperlinearity. Significant interactions between the 2282del4 FLG mutation and the CT genotype for IL‐13 or GG genotype for IL‐10 and a higher risk for developing AD were demonstrated. Conclusion: FLG mutation, alone and in combination with certain IL‐10 or IL‐13 polymorphisms, enhances the risk for the development of AD in the Polish population.     

Beta defensin‐1 gene (DEFB1) polymorphisms are not associated with atopic dermatitis in children and adolescents from northeast Brazil (Recife,Pernambuco)

Background Atopic dermatitis (AD) is a common inflammatory skin disease resulting from the interplay between environmental, immunological and genetic factors. In our study, we investigated the role of three single nucleotide polymorphisms (SNPs) at 5′‐UTR of DEFB1 gene, encoding for the human beta defensin‐1, on the susceptibility to develop AD in a group of Brazilian children and adolescents. Methods Three SNPs, ?20 G/A (rs11362), ?44 C/G (rs1800972), and ?52 G/A (rs1799946) at 5′‐UTR of DEFB1 gene were genotyped in two groups of children and adolescents, one affected by AD (96 subjects), the other healthy (191 individuals), from northeast Brazil. Results ?44 C/G frequencies were comparable between the two groups. The ?20 GG genotype was more frequent in AD subjects than in healthy controls; the ?52 GG, conversely, was more frequent in healthy controls than in AD. However, both these differences did not reach statistical significance. Also, association between SNPs and AD severity has been shown. The analysis of DEFB1 haplotypes did not highlight any association of the three SNPs with AD development or disease severity. Conclusions Our results seem to exclude a role for the ?44 C/G DEFB1 SNPs on the pathogenesis and severity of AD, while for the ?20 C/G and ?52 G/A, even if not statistically significant, we evidenced a slight trend for susceptibility (?20 GG) and protection (?52 GG) for the development of AD. However, as controversial findings have been reported in the literature, the role of DEFB1 in the development of AD and in the severity of the phenotype deserves further investigation.     

Monilethrix: a novel mutation (Glu402Lys) in the helix termination motif and the first causative mutation (Asn114Asp) in the helix initiation motif of the type II hair keratin hHb6.

Monilethrix, a rare human hair disorder with autosomal dominant transmission, can be caused by mutations in hair keratins. Up to now, causative mutations have only been found in two type II cortex keratins, hHb6 and hHb1. In these hair keratins, the helix termination motif, HTM, was the only site in which mutations were located. The most frequent mutation, which has been found in 22 cases, was a Glu413Lys substitution in hHb6, whereas other mutations, i.e., hHb6 Glu413Asp, hHb1 Glu413Lys, and hHb1 Glu402Lys, have been reported in a distinctly lower number of cases. In this study, we describe the equivalent of the hHb1 Glu402Lys mutation in the HTM of cortex keratin hHb6. The mutation occurred in an American family in which it could only be detected in one clinically affected individual. Thus the underlying G-->A transition represents a spontaneous germ-line mutation in the hHb6 gene. This new mutation indicates that both the hHb6/hHb1 Glu413Lys substitution and the hHb6/hHb1 Glu402Lys substitution, represent mutational hotspots in the HTM of type II cortex keratins. However, we also describe a monilethrix-causing mutation in the helix initiation motif, HIM, of the cortex keratin hHb6. The critical Asn114Asp substitution was only found in affected members of a large Swedish three-generation family. Considering that since childhood, half of the affected individuals suffer from complete baldness and follicular keratosis, the new HIM mutation seems to be associated with a rather severe disease phenotype. In conclusion, our data strongly suggest that monilethrix is a disease of the hair cortex, whose etiology is interesting in that causative mutations seem to be restricted to type II hair keratins.     

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.     

Clinical Characteristics and Genetic Variations in Early-Onset Atopic Dermatitis Patients

BackgroundHereditary factors contribute to atopic dermatitis (AD) development. We developed the reverse blot hybridization assay (REBA) kit to simultaneously detect variations in skin barrier- and immune response-related genes prevalent in Korean AD patients.ObjectiveTo identify genetic variations and clinical characteristics that could predict early AD development.MethodsWe compared AD-related genetic variations between early-onset AD subjects and non-AD controls, and clinical characteristics and genetic variations between early- and late-onset AD subjects. We compared 28 early-onset AD subjects and 57 non-AD controls from a birth cohort and 108 early- (age ≤3 years) and 90 late-onset AD subjects and 189 non-AD controls from a university hospital. Genetic variations were detected via REBA.ResultsThere were no differences in AD-related genetic variation between early-onset AD subjects and non-AD controls in the birth cohort. When the birth cohort and hospital populations were combined, early-onset AD subjects and non-AD controls showed different frequencies of genetic variations of KLK7, SPINK5 1156, DEFB1, IL5RA, IL12RB1a, and IL12RB1b. No differences in the frequency of genetic variations were observed between early- and late-onset AD subjects. Immunoglobulin E positivity for house dust mites was prevalent in late-onset AD subjects. A family history of atopic diseases was associated with early-onset AD.ConclusionNo AD-related genetic variations could predict early AD development in Koreans, even though neonates with a family history of atopic diseases are likely to develop AD at ≤3 years of age. Environmental exposure may be more important than genetic variation in determining the onset age of AD.     

Haploinsufficiency caused by a nonsense mutation in NCSTN underlying hidradenitis suppurativa in a Chinese family

Hidradenitis suppurativa (HS) is a chronic disease of follicular occlusion. It involves the axilla, groin, perianal and perineal regions, and is characterized by recurrent draining sinuses, skin abscesses and disfiguring scars. Loss‐of‐function mutations in the genes encoding γ‐secretase have been identified as a cause of HS. We collected skin samples from three patients with HS from a Chinese family carrying a NCSTN mutation (c.1258C>T (p.Q420X)) and three unrelated healthy controls (HCs). Expression level of nicastrin in skin tissue and cultured keratinocytes and fibroblasts of patients and HCs was determined by real‐time quantitative PCR and western blotting. We found that the mRNA and protein levels of nicastrin were significantly reduced in the whole skin, epidermis, dermis, and cultured keratinocytes and fibroblasts compared with HCs. Therefore, we conclude that haploinsufficiency of the NCSTN gene caused by the nonsense mutation c.1258C>T (p.Q420X) contributes to the occurrence of HS in this family.     

One novel and two recurrent mutations in the keratin 5 gene identified in Chinese patients with epidermolysis bullosa simplex

Epidermolysis bullosa simplex (EBS) is a group of inherited skin diseases, characterized by the formation of intraepidermal blisters. We performed genetic analysis of the keratin 5 (KRT5) gene in two Chinese pedigrees. One novel missense mutation was identified in a patient with sporadic EBS (general, non‐Dowling–Meara). Sequence analysis showed a heterozygous T > A transition at nucleotide 1730 of KRT5, changing phenylalanine (Phe) to tyrosine (Tyr) at position 577 of the keratin 5 (K5). In addition, two recurrent mutations c.1649delG (p.Gly550AlafsX77) and c.508G > (p.Glu170Lys) in KRT5 were identified in Chinese patients with mottled pigmentation EBS and localized EBS, respectively. None of the mutations were found in any unaffected family members or in an additional 100 unrelated control samples. These results suggest that these mutations are pathogenic and might be one of the potential causes of EBS in these Chinese patients.     

Analysis of SPINK 5, KLK 7 and FLG genotypes in a French atopic dermatitis cohort

The role of a genetically impaired epidermal barrier as a major predisposing factor in the pathogenesis of atopic disorders is currently under closer investigation. Variants on three candidate genes (SPINK5, KLK7 and FLG) have been associated with atopic dermatitis. A functional relevance has already been established for filaggrin variants, but not for SPINK5 and KLK7 polymorphisms. The objectives of this study were to confirm the association between SPINK5, KLK7, FLG variants and atopic dermatitis and to assess how variants influence selected phenotypic traits. This cross-sectional study was carried out over 20 months in 99 children and adults with atopic dermatitis (median age 7 years). The following items were analysed: SCORAD, TEWL, ichthyosis vulgaris, presence of asthma, total IgE serum levels. The SPINK5 E420K SNP, the KLK7 4bp insertion polymorphism and the filaggrin mutants (R510X and 2282del4) were analysed as described previously. The control group for genetic analysis was recruited in an ethnically matched, phenotypically anonymous cohort (n=102). The allelic frequencies were 0.525 for SPINK5, 0.26 for KLK7 polymorphisms, 0.101 and 0.075 for 2282del4 and R501X FLG mutants, respectively. The association of atopic dermatitis with filaggrin variants was confirmed, but not that of SPINK5 or KLK7 polymorphisms. SCORAD and TEWL measurements were not influenced by any of the variants. The SPINK5 polymorphism was associated with high IgE serum levels (p=0.011). Abnormal barrier genes do not influence the severity of atopic dermatitis. The SPINK5 gene polymorphism may modulate systemic immune effects favouring the IgE response to atopens. TEWL does not allow the characterization of subsets of patients with or without abnormal barrier genes.     

Hint for association of single nucleotide polymorphisms and haplotype in SPINK5 gene with atopic dermatitis in Koreans

Clinical studies, including twin studies, support the concept that the risk of atopic dermatitis (AD) may be mediated through skin-specific genes, rather than simply through systemic immune or atopy risk genes. The SPINK5 gene is expressed on epithelial surfaces and may provide protection against other allergenic serine proteases. Mutations in the SPINK5 gene result in Netherton syndrome, a disorder characterised by AD, ichthyosis, and elevated serum IgE levels. We genotyped 21 single nucleotide polymorphisms (SNPs) from the SPINK5 gene for 1090 case-control samples (631 patients with AD and 459 normal controls) and analysed the SNPs and haplotypes in this gene and also searched for gene-gene interactions between SPINK5 and the DEFB1 gene that we previously reported. Six SNPs [rs17718511 (P = 0.026), rs17860502 (P = 0.024), KN0001820 (P = 0.045), rs60978485 (P = 0.007), rs17718737 (P = 0.02), and rs1422985 (P = 0.038)] and the haplotype TAA (rs60978485, rs6892205, rs2303064; P = 0.023) in the SPINK5 gene showed significant different allelic or genotypic distributions between the AD group and the control group. We also found that four SNPs [rs17718511 (P = 0.033), rs17860502 (P = 0.031), rs60978485 (P = 0.005), rs17718737 (P = 0.023)] and the haplotype TAA (P = 0.02) in the SPINK5 gene showed associations with the susceptibility of the allergic type of AD (ADe). In addition to this finding, we speculate that the SNPs from DEFB1 and SPINK5 affect the individual susceptibility to development of ADe in an additive manner. This study provides evidence for a significant interaction between allergens and the SPINK5 gene that may contribute to ADe susceptibility.     

Brain-derived neurotrophic factor gene polymorphisms and serum levels in Chinese atopic dermatitis patients

Background  Brain-derived neurotrophic factor (BDNF) plays an important role in the pathogenesis of atopic dermatitis (AD). Whether BDNF gene polymorphisms are associated with Chinese AD remains totally unknown.
Objective  The aim is to determine if BDNF gene C270T and G196A polymorphisms are associated with Chinese AD, and analyse the clinical relevance of BDNF gene polymorphisms and BDNF serum levels.
Methods  We conducted a case-control association analysis (160 patients and 169 controls) in Northern Chinese subjects. Genotyping was performed by restriction fragment length polymorphism, and serum levels of BDNF were measured using enzyme-linked immunosorbent assay.
Results  For C270T, there were significant differences in C/T genotype distribution ( P  = 0.003) and T allele frequencies ( P  = 0.004) between AD patients and controls in the whole dataset. Higher C/T genotype frequencies were found in male AD (10.6% vs. 1.1%, P  = 0.018) and in intrinsic AD (IAD; 15.79% vs. 2.91%, P  = 0.008). No association between G196A polymorphism and AD was observed in the whole cohort, while A allele was much more frequent in AD patients with atopy in first-degree relatives (65.8% vs. 34.2%, P  = 0.038). Serum BDNF levels were correlated with IAD severity as measured by Scoring Atopic Dermatitis index ( r  = 0.576, P  < 0.001).
Conclusion  T allele in C270T may be a risk factor for AD, especially in IAD and male AD. A allele in G196A may be a risk factor in AD patients with atopy in first-degree relatives. Serum BDNF levels were correlated with the severity of IAD.     

Cytokine gene polymorphisms in atopic dermatitis

BACKGROUND: Atopic dermatitis (AD) and psoriasis are genetically determined inflammatory skin disorders characterized by abnormal cytokine production. From association studies there is evidence that functionally relevant cytokine gene polymorphisms contribute to the genetic basis of psoriasis. Association studies in AD have mostly been limited to polymorphisms of T-helper 2-type cytokines, which dominate in acute AD lesions. Unexpectedly, the results of recent genome scans indicate linkage of AD to psoriasis susceptibility loci. Therefore, AD may also be influenced by genes that modulate cutaneous inflammation independently from atopic mechanisms. OBJECTIVES: To investigate further the role of cytokine gene polymorphisms in AD. METHODS: Polymorphisms in the genes encoding tumour necrosis factor-alpha (TNFA-238 G/A, -308 G/A), interleukin (IL)-1beta (IL1B-511 T/C, +3953 T/C), IL-6 (IL6-174 C/G), IL-10 (IL10-1082 A/G) and the IL-1 receptor antagonist (IL1RN intron 2) were investigated in German patients with AD (n = 94) and in healthy nonatopic individuals (n = 214) by polymerase chain reaction-based methods and direct cycle sequencing. RESULTS: No association was found between AD and any of the polymorphisms analysed. This is in contrast to the recently described association between psoriasis and the TNFA-238 and IL1B-511 polymorphisms. CONCLUSIONS: Our data indicate that cytokine gene polymorphisms may act as specific markers of inflammatory skin diseases rather than contribute to a general disposition towards cutaneous inflammation.