Platelet mass index is increased in psoriasis. A possible link between psoriasis and atherosclerosis

INTRODUCTION: Psoriasis, whose relation with atherosclerosis etc. has long been known, is a chronic inflammatory disease. Besides providing hemostasis, platelets play important roles in inflammatory reactions and immune responses and contribute to endothelial damage, thus leading to atherosclerotic plaque formation. Mean platelet volume (MPV) has been previously reported as a platelet activation marker. Platelet mass index (PMI) is also related to platelet functionality and is thought to be a useful parameter for plaque formation capacity of platelets. MATERIAL AND METHODS: Sex, age, age of onset, disease duration, family history, psoriasis area severity index, nail and joint involvement, platelet count, mean platelet volume, platelet mass index, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) of 320 patients with psoriasis and 200 healthy persons were evaluated. RESULTS: Mean platelet counts were 277.7 ±73.374 and 265.06 ±59.682 (p = 0.032); MPV values were 8.248 ±1.150 and 7.442 ±1.626 (p < 0.001); and PMI values were 2259 ±545.617 and 1964 ±622.762 (p < 0.001) respectively in the psoriasis and control group. The MPV showed a significant but inverse correlation with hs-CRP (p = 0.047, r = –0.149), and no correlation with ESR (p > 0.05). Platelet count and PMI had a significant and positive correlation with ESR (p < 0.001, r = 0.404 and p < 0.001, r = 0.371), but had no correlation with hs-CRP (p > 0.05). CONCLUSIONS: Higher PMI and MPV values, which mean higher plaque formation capacity and more active platelets, in psoriasis may make psoriasis patients more sensitive to atherosclerotic plaque formation and complications. On the other hand, because of the positive PMI correlation with ESR (MPV had no correlation with ESR and had a negative correlation with CRP), PMI may be a better predictor of inflammation than MPV in psoriasis.