Platelet activation in patients with systemic scleroderma--pattern and significance.

UNLABELLED

The vasooclusive features of scleroderma are attributed to the vessel wall anomalies, while platelet's intervention is less studied.

AIM

platelet activation markers (PAM) pattern and significance in systemic sclerosis.

DESIGN

20 scleroderma patients with severe Raynaud phenomenon, under aspirin treatment, were evaluated by quantitative flow-cytometry for PAM (P-selectin, GPIIbIIIa, CD40L) in correlation with scleroderma activity and severity, systemic endothelial dysfunction (flow-mediated vasodilatation), systemic inflammation (serum CRP and IL-6) and cold-provocation test. Associated autoantibodies (ANCA, antiTPO, anticardiolipin, antiplatelet, antimitochondrial antibodies) were evaluated in relation to IL-6.

RESULTS

PAM were expressed in 11 (55%) cases: P-selectin in 5 (45.45%), GPIIbIIIa in 1 (9.1%), combined P-selectin and GPIIbIIIa in 5 (45.45%), CD40L in 0 cases. Scleroderma patients expressing PAM had increased incidence of disease activity and severity. There was no correlation between PAM and systemic endothelial dysfunction. CRP increased in 14(70%) cases was correlated with P-selectin and GPIIbIIIa expression (r = 0.28). Normal IL6 present in 19 (90.9%) cases was correlated with lack of CD40L expression (r = 0.69) and with low autoantibodies incidence (r = 0.69 for ANCA, 0.55 for anti TPO and antiplatelet, 0.39 for anti cardiolipin, 0.45 for antimitochondrial). After cold provocation test PAM were significantly lost and were not expressed de novo.

CONCLUSIONS

In systemic scleroderma platelet activation markers are correlated with disease activity and severity and increased CRP and are not correlated with systemic endothelial dysfunction or exposure to cold. Normal IL-6 was correlated with lack of CD40L expression and with low incidence of associated autoantibodies.