Polymorphism of the E-cadherin gene CDH1 is associated with susceptibility to vitiligo.

Vitiligo is a depigmenting disorder characterized by loss of functional melanocytes from the epidermis. Experimental data suggest that defective melanocyte adhesion may underlie the pathogenesis of the disease. In particular, association between vitiligo and genetic variants of the DDR1 gene involved in melanocyte adhesion has been recently published. A subsequent, independent study revealed lower expression of DDR1 in vitiligo lesions. Here, we expand this investigation by testing for association between vitiligo and polymorphisms of CDH1, IL1B and NOV (formerly CCN3), genes belonging to the DDR1 adhesion pathway, in two population samples of distinct design. Our results reveal that alleles of marker rs10431924 of the CDH1 gene are associated with vitiligo, especially in the presence of autoimmune comorbidities.

A pattern of association between clinical form of vitiligo and disease-related variables in a Brazilian population.

BACKGROUND: Vitiligo classification systems are often based exclusively on the number and distribution of the white patches. To what extend these classification protocols reflect possible different pathophysiological basis for vitiligo or carry any prognostic value is currently unknown. OBJECTIVE: To investigate patterns of association between type of vitiligo and common disease-related variables, in order to advance on the understanding of the exact nature of different clinical forms of disease, as well as to identify features with prognostic value for clinical progression of early diagnosed vitiligo. MATERIALS AND METHODS: This is a cross-sectional study of a population sample from south of Brazil composed of 586 independent vitiligo-affected individuals. Different strategies of case-control analysis were employed to test for association between the three most common vitiligo clinical types and age of onset, family history of vitiligo, occurrence of Köebner phenomenon (KP) and presence of autoimmune co-morbidity. RESULTS: Individuals affected by segmental vitiligo showed lower average age of onset (16 years) when compared with vulgaris (23.9 years) and acrofacial cases (29 years) (p<0.001). The distribution of occurrence of KP, family history of vitiligo and co-occurrence of autoimmune disease followed a gradient pattern, with high, intermediate and low chance of occurrence of all three variables observed for vulgaris, acrofacial and segmental vitiligo, respectively (p<0.001 for overall distribution). CONCLUSION: Results indicate a uniform pattern of association between vitiligo clinical forms and KP, positive vitiligo family history and occurrence of co-morbidity autoimmune. The impact of the observed pattern of association over disease prognosis and classification is discussed.

EpHLA software: a timesaving and accurate tool for improving identification of acceptable mismatches for clinical purposes.

UNLABELLED: The HLAMatchmaker algorithm, which allows the identification of "safe" acceptable mismatches (AMMs) for recipients of solid organ and cell allografts, is rarely used in part due to the difficulty in using it in the current Excel format. The automation of this algorithm may universalize its use to benefit the allocation of allografts. Recently, we have developed a new software called EpHLA, which is the first computer program automating the use of the HLAMatchmaker algorithm. Herein, we present the experimental validation of the EpHLA program by showing the time efficiency and the quality of operation. The same results, obtained by a single antigen bead assay with sera from 10 sensitized patients waiting for kidney transplants, were analyzed either by conventional HLAMatchmaker or by automated EpHLA method. Users testing these two methods were asked to record: (i) time required for completion of the analysis (in minutes); (ii) number of eplets obtained for class I and class II HLA molecules; (iii) categorization of eplets as reactive or non-reactive based on the MFI cutoff value; and (iv) determination of AMMs based on eplets' reactivities. We showed that although both methods had similar accuracy, the automated EpHLA method was over 8 times faster in comparison to the conventional HLAMatchmaker method. In particular the EpHLA software was faster and more reliable but equally accurate as the conventional method to define AMMs for allografts. CONCLUSION: The EpHLA software is an accurate and quick method for the identification of AMMs and thus it may be a very useful tool in the decision-making process of organ allocation for highly sensitized patients as well as in many other applications.

Genetic variants of the DDR1 gene are associated with vitiligo in two independent Brazilian population samples.

Vitiligo is a chronic disease characterized by macules devoid of melanin and identifiable melanocytes. Adhesion of melanocytes to the basement membrane by integrin CCN3 is mediated through collagen IV receptor DDR1. We hypothesize that genetic variants of the DDR1 gene are associated with the occurrence of vitiligo. To test this hypothesis, we genotyped 10 DDR1 tag single-nucleotide polymorphisms (SNPs) in 212 trios composed of an affected child and both parents. Associated markers were then genotyped in 134 independent, unrelated individuals with vitiligo and 134 unrelated controls. Allele T of tag SNP rs4618569 was associated with an increased risk for vitiligo in the family trios (P=0.002, odds ratio (OR)=5.27; 95% confidence interval (CI)=1.59-17.40), whereas allele C of tag SNP rs2267641 was associated with an increased risk for vitiligo in both family-based and case-control populations (P=0.01, OR=3.47; 95% CI=1.22-9.17; P=0.04, OR=6.00; 95% CI=1.73-52.33, respectively). The best evidence for association in the trios was obtained for a haplotype composed of risk alleles of markers rs4618569 and rs2267641 (P=0.0006). There was an age-dependent enrichment of rs4618569 T allele and rs2267641 C allele in early-onset affected individuals. In conclusion, we propose DDR1 as a susceptibility gene for vitiligo, possibly implicating a defective cell adhesion in vitiligo pathogenesis.