624 Clinical and immune analysis of mesenchymal stromal cells (MSCs) for multiple biologic-resistant psoriasis

Biologics have transformed the management of moderate-to-severe psoriasis; however, none are curative, and an increasing number patients failed all available classes. MSCs, multipotent stem cells with immunomodulatory properties been used to treat immune-mediated inflammatory diseases including rheumatoid arthritis Crohn disease. We investigated efficacy safety umbilical cord-derived MSCs in 2 adults severe, multiple biologic-resistant psoriasis. were infused intravenously at a dose 2.2–3x106cells/kg on Day (D) 0 D7. Both Patient 1(46yo F, baseline PASI 37.8, DLQI 27) (45yo 13.8, 15) had 4 classes biologics. At time infusion, 1 was unresponsive etanercept failing guselkumab. 1: by D7, itch reduced 50% D16, 23.0 (-39%) 10. D70, maintained 21.8. Co-morbidities included type diabetes psoriatic arthritis(PsA). PsA tender joint count 13; 9 D16. 2: D3, 90%; 8.2 (-41%) 12. D28 1.8 (-87%) 8. MSC infusions well tolerated without adverse events. For 1, immunophenotyping peripheral blood mononuclear baseline, D7 D42 post-infusion revealed changes myeloid lymphoid cell compartments. Frequency dendritic cells(p<0.01 D42) monocytes(p<0.01 significantly decreased over time, latter shifting from classical non-classical phenotype (p<0.05 D42). CD8+CLA+CD103- skin homing T displaying mixed T1/T17 increased (p<0.05), suggesting pathogenic cells. Taken together, appear changed immune profile. In conclusion, these data supportive immunomodulation for severe psoriasis lines