Macrophage migration inhibitory factor gene polymorphisms (SNP -173 G>C and STR-794 CATT5-8) confer risk of plaque psoriasis: A case-control study.

BACKGROUND: Macrophage inhibitory factor (MIF) is a pro-inflammatory cytokine secreted by several cells, including those in the immune system and the skin. The MIF gene contains the SNP -173 G> C and STR -794 CATT5-8 polymorphisms in the promoter region capable of affecting its activity. Our objective was to investigate the MIF polymorphisms as a risk factor for plaque psoriasis (PP) in the Mexican population. METHODS: We genotyped both MIF polymorphism (rs5844572 and rs755622) in 224 PP patients with a clinical and histopathological diagnosis and 232 control subjects (CS) by the PCR-RFLP method. MIF serum levels were determined by an ELISA kit. RESULTS: We found significant differences in the genotypic and allelic frequencies for the MIF -173 G>C polymorphism; carriers of the GC genotype (OR 1.51, 95% CI 1.026-2.228, p = 0.03) and the C allele (OR 1.34, 95% CI 1.005-1.807, p = 0.04) had higher odds to present with PP. Moreover, the 6C haplotype was associated with PP risk (OR 2.10, 95% CI 1.22-3.69, p < 0.01). Also, the -173 CC genotype was associated with high MIF serum levels (p < 0.05). CONCLUSIONS: The -173 GC genotype and the 6C haplotype of the MIF polymorphisms are associated with susceptibility to PP in the Mexican population.

Diversity of KIR/HLA Genotypes and Their Association with Psoriasis Vulgaris in the Western Mexican Population.

NK and some T cell functions are regulated by the interaction between KIR and HLA molecules. Several studies have shown an association between activating KIR genes and the development of autoimmune diseases, including psoriasis vulgaris (PsV). Our objective was to determine the association between KIR/HLA genes and genotypes with PsV in the Western mestizo Mexican population. One hundred subjects diagnosed with PsV (SP) and 108 healthy subjects (HS) were genotyped for 14 KIR genes, HLA-Bw4, HLA-C1, and HLA-C2 by PCR-single specific primer (SSP). Positive associations of the KIR3DS1 gene (odds ratio (OR) 1.959, p = 0.021), G11 genotype (OR 19.940, p = 0.008), and KIR3DS1/HLA-ABw4 (OR 2.265, p = 0.009) were found with susceptibility to PsV. In contrast, the G1 genotype (OR 0.448, p = 0.031) and KIR3DL1/HLA-Bw4Ile80 (OR 0.522, p = 0.022) were negatively associated with susceptibility to this disease. These results suggest an implication of the KIR3DS1/HLA-ABw4 genotype in PsV pathology.

Body Region Involvement and Quality of Life in Psoriasis: Analysis of a Randomized Controlled Trial of Adalimumab.

BACKGROUND: Psoriasis severity and treatment responsiveness vary by body region, which differentially impacts quality of life (QoL). OBJECTIVE: The objective of the study was to examine adalimumab efficacy by body region and regional response and QoL relationship. METHODS: Patients (n = 1212) with moderate-to-severe psoriasis were randomized 2:1 to 80 mg at week 0, followed by adalimumab 40 mg or placebo every other week for 16 weeks in the double-blind REVEAL study. Psoriasis Area and Severity Index (PASI) responses and Dermatology Life Quality Index outcomes were analyzed. RESULTS: Week 16 regional mean PASI improvements were significantly greater with adalimumab (83.1 ± 1.57, 81.3 ± 1.58, 75.7 ± 1.34, and 73.9 ± 1.26% in the trunk, head, upper extremities, and lower extremities, respectively; all p < 0.001 vs. placebo). Likewise, percentages of patients with regional PASI ≥75/≥90/100% reduction from baseline were significantly higher with adalimumab (all p < 0.001); adalimumab responses were greater for the trunk (77.9/65.0/59.1%) and head (74.6/66.1/62.8%; all p ≤ 0.0001 vs. lower) than upper (67.7/45.1/39.6%; p = 0.4, p = 0.04, p = 0.0005, respectively, vs. lower) and lower extremities (65.7/40.0/31.3%). Adalimumab significantly improved Dermatology Life Quality Index scores vs. placebo (8.2- vs 1.7-point decrease from baseline; p < 0.001). LIMITATIONS: The study was a post hoc analysis. CONCLUSIONS: Adalimumab treatment resulted in statistically significant and clinically meaningful improvements in disease severity and QoL. QoL improvements were associated with PASI responses in all body regions. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT00237887.

The 3'UTR 1188A/C polymorphism of IL-12p40 is not associated with susceptibility for developing plaque psoriasis in Mestizo population from western Mexico.

Psoriasis is a chronic autoimmune inflammatory disease that affects the skin and the joints. Psoriasis is characterized by the keratinocyte proliferation, which is induced by cytokines Th1 and Th17. Patients with plaque psoriasis present a chronic inflammatory response with high levels of interleukin (IL)-12 and IL-23. Various single-nucleotide polymorphisms (SNP) have been identified in the IL12B gene, such as SNP 3' UTR 1188 A/C (SNP rs3212227), which has been associated with susceptibility to developing plaque psoriasis and with the production of IL-12 and IL-23 in individuals of different ethnic groups. In this study, we determined whether there is an association of SNP rs3212227 with the susceptibility of developing plaque psoriasis and with serum levels of IL-12 and IL-23 in Mestizo population in western Mexico. We included 112 patients with psoriasis and 112 clinical healthy individuals in the study. The frequencies of genotypes A/A, A/C, and C/C in patients with plaque psoriasis were 41, 53, and 6%, respectively, while in the control group, these were 37, 53, and 10%, respectively, without finding statistically significant differences between both groups (p>0.05). Although IL-12 and IL-23 serum levels were higher in patients than in controls, we found no significant differences. The group of patients with genotype CC presented the highest levels of IL-23 (p<0.05). These data suggest that the SNP rs3212227 phenotype is not associated with the risk of developing plaque psoriasis or with IL-12 and IL-23 levels in Mestizo population in western Mexico.