Lymphocyte-Platelet and Neutrophil-Platelet Aggregates are Associated with Dysregulated Platelet Inflammatory Pathways in Psoriasis.

Abstract

Background: Psoriasis is a chronic immune-mediated inflammatory disease associated with heightened cardiovascular risk. Platelets are increasingly implicated in this link through their capacity to amplify vascular inflammation and interact with leukocytes. Circulating leukocyte-platelet aggregates are elevated in psoriasis, although the biological significance of these aggregates remains incompletely understood. We investigated whether increased leukocyte-platelet aggregates is associated with alterations in the platelet transcriptomic profile in psoriasis.

Methods: Leukocyte-platelet aggregate levels were compared between psoriasis patients (n = 42) and healthy controls (n = 29). Psoriasis patients were stratified by the cohort median lymphocyte-platelet aggregate (LyPA) or neutrophil-platelet aggregate (NPA) levels into high vs low aggregate groups. Platelet RNA sequencing was then performed to define transcriptomic differences in high-vs low-aggregate psoriasis.

Results: Psoriasis patients (mean age 46; 60% male; 81% Caucasian) had higher LyPA (P = 0.001) and NPA (P = 0.04) compared with healthy controls (mean age 42; 55% male; 69% Caucasian). Platelet RNA sequencing revealed that psoriasis patients with high LyPA or high NPA had downregulation of platelet inflammatory pathways, including interferon, tumor necrosis factor (TNF), IL-8, and IL-6 signaling.

Conclusion: These findings identify inflammatory platelet transcriptomic alterations associated with elevated lymphocyte-platelet and neutrophil-platelet aggregates in psoriasis and motivate further work to define the functional consequences of leukocyte-platelet aggregates in psoriasis.