Identification of plaque psoriasis subgroups based on peripheral blood immune cells subtypes and their relationship with biologic therapy efficacy: a single-center longitudinal cohort study in China

Background Psoriasis is an immune-mediated inflammatory skin disease with variable biologic therapy response. Current treatment selection lacks reliable predictive biomarkers for personalized decisions.Objectives To identify distinct immunological patient subgroups based on peripheral blood immune cells and evaluate their association with biologic therapy efficacy.Methods This retrospective cohort study included 329 plaque psoriasis patients initiating first-time biologic therapy and 169 healthy controls. Peripheral blood flow cytometry data were analyzed using hierarchical clustering. Kaplan-Meier analysis assessed time to PASI90 achievement among subgroups.Results Psoriasis patients showed significantly elevated lymphocyte populations. Three distinct immunological clusters were identified: Cluster 1 (57.8%) with moderate T cells and low NK cells; Cluster 2 (27.7%) with decreased T cells and increased NK cells; and Cluster 3 (14.6%) with increased total lymphocytes. Cluster 1 patients achieved PASI90 significantly faster with both IL-17 and IL-23 inhibitors (p < 0.001).Conclusion Peripheral blood flow cytometry identified distinct psoriasis immunophenotypes with significant differences in biologic therapy response, offering potential biomarkers for treatment selection and personalized medicine approaches.