33945 DNA copy number variations associated with different clinical phenotypes of psoriasis and paradoxical anti-TNF induced palmoplantar pustulosis

Abstract

Certain DNA regions have copy number variations (CNVs) caused by duplications or deletions that result in higher or lower number of copies. Those CNVs can modify genome structure and transposable elements within a region thus affecting gene expression. They have been reported in healthy individuals, in different pathologies such as cancer or autoimmune diseases and they can also be used as diagnostic biomarkers in several diseases such as psoriasis. The aim of this study is to identify if there are CNVs associated with these different clinical phenotypes, which could justify the differences found in clinical practice. Moreover, we intend to elucidate if anti-TNF induced palmoplantar pustulosis have a similar genetic background than the idiopathic palmoplantar pustulosis. Skin samples were collected from 39 patients with different patterns of psoriasis, and 6 patients with anti-TNF induced palmoplantar pustulosis. CNVs were obtained from methylation array data (Illumina Infinium Human Methylation) using conumee R package. No significant CNVs were found between the different phenotypes and locations compared. Nevertheless, we found 2 significant bins harboring 5 different genes associated with anti-TNF induced palmoplantar pustulosis in patients with a different background than psoriasis. Our results may help to predict which patients could develop an anti-TNF induced palmoplantar pustulosis.