Platelet function studies in myeloproliferative neoplasms patients with or mutation.

BACKGROUND

and mutations are the most frequent molecular causes of -negative myeloproliferative neoplasms (MPN). Patients with mutations are at lower risk of thrombosis than patients with . We hypothesized that -mutated blood platelets would have platelet function defects that might explain why these patients are at lower risk of thrombosis.

OBJECTIVES

Our main objective was to explore and compare platelet function depending on the MPN molecular marker.

METHODS

We analyzed platelet function in 16 patients with MPN with mutations and 17 patients with mutation and compared them with healthy controls. None of these patients was taking antiplatelet therapy. We performed an extensive analysis of platelet function and measured plasmatic soluble P-selectin and CD40L levels.

RESULTS

We observed significant defects in platelet aggregation, surface glycoprotein expression, fibrinogen binding, and granule content in platelets from patients with MPN compared with that in controls. Moreover, soluble CD40L and P-selectin levels were elevated in patients with MPN compared with that in controls, suggesting an platelet preactivation. Comparison of platelet function between patients with and MPN revealed only minor differences in platelets from patients with . However, these results need to be interpreted within the context of absence of an inflammatory environment that could impact platelet function during MPN.

CONCLUSIONS

These results do not support the hypothesis that calreticulin-mutated platelets have platelet function defects that could explain the lower thrombotic risk of patients with .