Platelet activation in patients with psoriasis: increased plasma levels of platelet-derived microparticles and soluble P-selectin.

Background: It has recently been established that platelets have an important role in increasing inflammation, in addition to their main role in hemostasis and thrombosis. An increased incidence of occlusive vascular disease has been reported in patients with psoriasis and the pathomechanism of psoriasis may involve platelet activation.

Objective: The goal of the study was to establish a clearer explanation of the association between platelet activation and psoriasis activity by investigating the levels of markers of platelet activation in patients with psoriasis and examining the relationship between the marker levels and a severity score for psoriasis.

Methods: Plasma levels of platelet-derived microparticles (PDMPs) and soluble P-selectin were measured by enzyme-linked immunosorbent assay as markers of platelet activation in 21 patients with psoriasis and 22 healthy control subjects. The relationships between the platelet activation markers and the Psoriasis Area and Severity Index score were investigated.

Results: Plasma PDMPs and soluble P-selectin levels were markedly higher in patients with psoriasis compared with those in healthy control subjects. There was a significant correlation between the PDMPs levels and the Psoriasis Area and Severity Index score, and the increased plasma PDMPs and soluble P-selectin levels were markedly reduced after clinical improvement occurred.

Limitations: The number of people evaluated was relatively small.

Conclusions: Our results show that blood platelets are activated in patients with psoriasis, especially in those with extensive disease, and suggest a close association between platelet activation and psoriasis activity. Plasma PDMPs level may be a useful indicator of the severity of psoriasis.