Leptin levels are higher in patients with psoriasis compared with those in controls. Future studies are warranted to clarify the association between leptin levels and the pathomechanism of psoriasis.

The results from our case control study and the meta-analyses indicate that the IRAK1 rs3027898 C allele is significantly associated with an increased risk of RA, especially in Asians.

Previous studies have suggested that psoriasis is associated with individuals who are overweight or obese. Omentin is a recently discovered adipokine that is involved in chronic inflammatory processes. This study evaluated the relationship between omentin and psoriasis, focusing on omentin-1 serum levels, skin expression of omentin-1, and omentin-1 gene polymorphism (rs2274907; Val109Asp). Levels of omentin-1 in serum samples from 44 patients with psoriasis and 38 healthy controls were analyzed by enzyme-linked immunosorbent assay. The expressions of omentin-1 were measured by immunohistochemistry in 3 psoriasis affected skins and 3 normal skins. The rs2274907 variant was typed using a SNaPshot assay in 354 cases and 214 controls. We found significantly lower serum levels of omentin-1 in psoriasis patients compared with healthy controls (p < 0.001) with an inverse correlation with the Psoriasis Area and Severity Index (p < 0.01). The comparison of genotype and allele distribution revealed no significant difference in genotype frequency between psoriasis patients and controls. Therefore, omentin-1 may have a role in the pathogenesis of psoriasis and might be a potential biological marker for psoriasis severity.

Our recent targeted sequencing study identified a missense single-nucleotide polymorphism rs72474224 (c.324C>T) in GJB2. To investigate the correlation between rs72474224 (c.324C>T) and subphenotypes of psoriasis, genotype data for rs72474224 (c.324C>T, p.Val37Ile) was analyzed in 9946 cases and 9906 controls. The additive model provided the best fit for rs72474224 (P = 7.34 × 10(-9)). The genotypic and allelic frequency distributions were associated with plaque psoriasis in case-only (Pgenotype = 2.67 × 10(-3), Pallele = 6.22 × 10(-4)) and subphenotype-control (Pgenotype = 1.58 × 10(-11), Pallele = 8.16 × 10(-12)) analyses. No other significant difference was found in case-only analyses. Rs72474224 in GJB2 is preferentially associated with plaque psoriasis in Chinese population and might contribute to the complexity of psoriasis clinical features.