236 The importance of inflammatory markers in generalized pustular psoriasis (GPP): An immunohistochemical analysis

GPP is a rare potentially life-threatening disease characterized by the presence of sterile pustules on erythematous skin. Although clinically different from psoriasis vulgaris (PV) it shares some features PV such as spongiform pustule. The cause unknown; triggers include infections, corticosteroid withdrawal and genetic factors mutation IL-36 RN antagonizing IL36-G -A. Antibody treatment with IL-36R antagonist spesolimab has shown efficacy. role other inflammatory not well understood. To further elucidate pathogenesis we performed an immunohistochemical study in 13 patients PPP corresponding skin 6 healthy control individuals. Skin biopsies were stained antibodies against HLA-DR, IL-8 recruiting neutrophils, IL-17A, IL-17F, IL-23, gamma, chemokine CXCR3 (CD183) IFN-induced inflammation, tyrosine kinase (Tyk) phospho-diesterase (PDE) 4B, transcription factor FOX-P3 T-cells JAK-3. slides photographed 20x enlargement Leica DFC 295 microscopic system digitally analyzed ImageJ Plugin-IHC Profiler scanning 82364 square micrometers. Stained cells ranged 50 to 365 per visual field. two-sided t-test served for statistical analysis. In compared controls, found following significance staining decreasing order: FoxP3 (p<0.00001), IL36 gamma (p<0.001), IL-17F (p<0.004), (p<0.03), (p=0.16), JAK-3 IL17A (p=0.20), Tyk (p=0.33) HLA-DR (0.58), PDE 4B (p=0.76). These results clearly indicate be dominant cytokine GPP. Moreover, FoxP3, cytokines IL-17 F, also exhibited significantly higher controls. Our may provide basis successful new generalized pustular psoriasis.