Platelet hyperaggregiability in cystic fibrosis

Platelet function was investigated in 15 patients with cycstic fibrosis (CF) and in ten age-matched controls. Marked hyperaggregability of platelets to adrenaline, collagen and arachidonic acid was observed in platelet rich plasma (PRP) prepared from patients with cystic fibrosis. Thromboxane A₂ (TXA₂) release from these platelets was also markedly enhanced. Hyperaggregability and increased TXA₂ release observed in patients with CF was not due to the higher platelet counts in these patients since hyperaggregability was observed even in those patients whise platelet counts were similar to those in controls. Platelet hyperaggregability and increased thromboxane release in these patients were also independent of their body weight and occurred despite supplementation with vitamin E. Hyperaggregability of platelets in CF may be clinically relevant since it may contribute to the pathogensis of bronchoconstriction through the release of TXA₂ and other bronchoconstrictor platelet products such as serotonin.