RESUMO
BACKGROUND: Psoriasis vulgaris is a common chronic inflammatory skin disease. Development of early onset psoriasis is, to some extent, genetically determined and a strong association with the major histocompatibility complex HLA-Cw6 has been demonstrated. The use of genome-wide association studies has highlighted novel genes associated with the development of psoriasis as IL12B, IL23R, TNFAIP3 and IL13 for instance. The majority of these studies were performed on cohorts of European descent. OBJECTIVE: To determine whether inter-ethnic differences exist in the genetic susceptibility to psoriasis, we genotyped single-nucleotide polymorphism variations in the vicinity of candidate genes in 132 Egyptian patients and 175 healthy controls. METHODS: Blood samples of patients and controls were screened for nucleotide polymorphisms in four candidate genes by TaqMan single-nucleotide polymorphisms Genotyping Assays. RESULTS: We found a significant association between psoriasis and the single-nucleotide polymorphism rs610604, within the TNFAIP3 gene. The TNFAIP3 gene is involved in the TNF-α signalling cascade (P-value: 0.004952), a key step in the pathogenesis of psoriasis. Although there was no significant association found between rs610604 (IL12B) and rs11209026 (IL23R) in this population, the interaction of these two genes showed a significant association with psoriasis (P-value: 0.025). Moreover, when selecting the patients with early disease onset (less than 30 years), we also found that the association of IL12B and psoriasis was highly significant (P-value 1.14 × 10(-12)). No association between rs20541 (IL13) and psoriasis was observed in our Egyptian cohort. CONCLUSION: Replicating the association of single-nucleotide polymorphisms in the TNFAIP3, IL12B and IL23R genes with psoriasis vulgaris, in subjects from different ethnic backgrounds, underlines their importance in the pathogenesis of the disease. In contrast, the lack of any association between rs20541 (IL13) and psoriasis in our Egyptian cohort suggests the existence of important inter-ethnic genetic differences in psoriasis susceptibility.
Assuntos
Proteínas de Ligação a DNA/genética , DNA/genética , Regulação da Expressão Gênica , Subunidade p40 da Interleucina-12/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteínas Nucleares/genética , Psoríase/genética , Adulto , Proteínas de Ligação a DNA/biossíntese , Egito/epidemiologia , Feminino , Frequência do Gene , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Subunidade p40 da Interleucina-12/biossíntese , Peptídeos e Proteínas de Sinalização Intracelular/biossíntese , Masculino , Proteínas Nucleares/biossíntese , Psoríase/epidemiologia , Psoríase/metabolismo , Proteína 3 Induzida por Fator de Necrose Tumoral alfa , Fator de Necrose Tumoral alfaRESUMO
BACKGROUND AND OBJECTIVE: In the last few years, outbreaks of an apparently specific dermatosis occurred during the months of late summer and early autumn in our locality. Our aim in this study was to reveal the underlying etiology of this dermatosis. SUBJECTS AND METHODS: Sixty patients with the disease were studied clinically, epidemiologically, histopathologically, and ultrastructurally. RESULTS: The results of all methods suggest that the dermatosis is most probably a human cowpox infection. Electron microscopy showed unenveloped cowpox virons. CONCLUSIONS: This apparently specific dermatosis is due to human cowpox infection. Future investigations will be needed to better define this important zoonosis frequently passed by cats to humans and carried by rodents.
