Elevation of ELISA d-dimer levels in patients with primary pulmonary hypertension

Background: Vasoconstriction, vascular wall remodeling and thrombosis are considered as possible etiologies of primary pulmonary hypertension (PPH). D-dimer, a degradation product of fibrin, has been increasingly used as a marker and prognostic factor in various diseases.

Objective: To assess elevated ELISA D-dimer levels as a marker of endogenous fibrinolysis in patients with PPH.

Patients and methods: Comparison of ELISA D-dimer levels of 12 PPH patients (11 female, 1 male) aged 27-73 years (median 51 years) with those of sex- and age-matched healthy controls.

Results: Eleven patients had New York Heart Association (NYHA) class III or IV symptoms, and one patient had NYHA class II symptoms. All patients with PPH were treated with anticoagulants and vasodilators: 5 patients were treated with continuous intravenous prostacyclin, 4 patients with continuous UT-15 and 2 patients with intermittent intravenous iloprost. Mean ELISA D-dimer levels +/- SD were significantly higher in the PPH group than in the matched control group (473 +/- 109 vs. 182 +/- 103 ng/ml; mean difference: 291 +/- 79, 95% CI: 240-341, p < 0.0001).

Conclusion: These results suggest the possible involvement of endogenous fibrinolysis in the pathophysiology of PPH.