Rationale: Although platelets are considered key inflammatory mediators in respiratory diseases, their role in bronchiectasis has not been fully explored.
Objectives: We hypothesized that thrombocytosis in stable state may be associated with bronchiectasis severity and worse clinical outcomes.
Methods: Bronchiectasis patients have been enrolled from 10 centers in Europe and Israel, with platelet count recorded during stable state. Primary outcome was five-year all-cause mortality. Secondary outcomes included exacerbations, hospitalizations, and mortality at one, two and three-year follow-up. Analyses were conducted using logistic regression after adjustment for confounding variables.
Results: Among the 1,771 patients (median age: 67 years; 63.4% females) included, 136 (7.7%) had thrombocytosis. Patients with thrombocytosis had a significant higher disease severity, worse quality of life, higher number of exacerbations and hospitalizations, and higher mortality rate at both three-year (23 [22.8%] vs. 83 [8.5%], respectively; p-value <0.01) and five-year (26 [35.1%] vs. 116 [15.9%], respectively; p-value <0.01) in comparison with those with normal platelet count. Thrombocytosis was significantly associated with hospitalizations due to severe exacerbations [OR (95% CI): 1.83 (1.20-2.79); p-value: 0.01] after one-year follow-up, as well as increased 3-year [OR (95% CI): 3.06 (1.74-5.39); p-value <0.01] and 5-year [OR (95% CI): 2.46 (1.39-4.37); p<0.01] mortality.
Conclusions: Platelets represent a cheap and easy to evaluate biomarker and the presence of thrombocytosis during stable state is associated with disease severity, hospitalizations due to exacerbations, poor quality of life and mortality in adults with bronchiectasis.