Differences in clinical characteristics and lesion proteomics between inflammatory linear verrucous epidermal nevus...

Verrucous epidermal nevus (VEN) are keratinocytic epidermal nevus that appear at birth or in early childhood. They exhibit a range of manifestations, depending on the patient's age. VEN are rarely encountered in clinical practice, and the systemic and comprehensive clinical characteristics of VEN have not been well investigated. Furthermore, the association between tandem mass tag (TMT)-based quantitative proteomics and the VEN phenotype is still unclear.

This study investigated the differences in the clinical characteristics and lesion proteomics between inflammatory linear VEN (ILVEN) and local VEN.

This retrospective study enrolled 125 patients with histopathologically diagnosed VEN who presented to our hospital between 2019 and 2021. We collected the clinical data of all patients with VEN using a self-designed questionnaire. The expression of proteins in VEN lesions was analyzed using TMT proteomics technology.

In total, there were 125 patients with VEN that were evaluated, including 67 (53.60%) patients with local VEN and 58 (46.40%) with ILVEN. No significant differences were found in sex, onset age, and lesion location between patients with local VEN and those with ILVEN (all P > 0.05). Significant differences were found in the onset site and pruritus scores between patients with ILVEN and those with local VEN (all P < 0.05). According to the TMT proteomics results, 89 proteins were up or downregulated with at least 1.3-fold (upregulated: 38, downregulated: 51; P < 0.05) in ILVEN lesions relative to VEN lesions. The top 10 differentially expressed proteins between ILVEN and local VEN lesions were OGN, NT5C3A, ADD1, OLFML1, DHRS1, CALML5, SAMHD1, SFRP2, SPRR1B, and SERPINB13. The upregulated proteins are mainly involved in neutrophil activation, neutrophil-mediated immunity, and p53 signaling pathway (hsa04115). The downregulated proteins are mainly involved in cellular response to cytokine stimulus, cell adhesion, Th1 and Th2 cell differentiation. In total, based on the differentially expressed proteins between ILVEN and local VEN, five pathways that may be associated with the pathogenesis of inflammation, including CAMs (P = 0.006), Th1 and Th2 cell differentiation (P = 0.017), PPAR signaling pathway (P = 0.023), Th17 cell differentiation (P = 0.024), and p53 signaling pathway (P = 0.041).

Clinical data of the patients revealed that ILVEN lesions presented with intense pruritus and inflammatory change. Differentially expressed proteins between ILVEN and local VEN are mainly involved in multiple inflammation related pathways associated with the pathogenesis mechanisms of pruritus.

The small sample size in clinical characteristic and proteomics study is one of the most significant limitations in our study. The inflammation associated proteins and signal pathways in the pathogenesis of pruritus in ILVEN is not explored.

In this study, we found the lesions of ILVEN patients presented with intense pruritus and inflammational change. A total of 89 proteins were up or downregulated with at least 1.3-fold (upregulated: 38, downregulated: 51; P < 0.05) in ILVEN lesions relative to VEN lesions. On the other hand, the etiology of itch in ILVEN mainly associated with inflammation, but the exact mechanisms was still unclear. We found the differentially expressed proteins between ILVEN and local VEN enriched five pathways that may be associated with the pathogenesis of inflammation and pruritus.