Abstract
Introduction: Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal disease of hematopoietic cells that occurs with complement-mediated hemolytic anemia. Hemolysis determines a significant increase of free hemoglobin in the circulation which results in a reduced concentration of nitric oxide (NO). The depletion of NO induces an increase in systemic and pulmonary vascular resistance, which could lead to the establishment of pulmonary hypertension.
Aim: to demonstrate, in PNH patients, high systemic oxidative stress, measurable through Nox2 on serum, 8-iso-PGF2α on urine and Flow Mediated Dilation (FMD) on brachial artery, compared with a healthy population.
Methods: Evaluation of high systemic oxidative stress in 25 PNH patients was measured through: NOX2 and H2O2 on serum, 8-iso-PGF2α on urine, spirometry, oximetry (during rest, exercise and sleep). Altered systemic vascular compliance was measured through FMD and echocardiograpy.
Results: dyspnea and reduced exercise tolerance were observed in all 25 PNH patients. Respiratory function tests, 6'WT and night pulse oximetry monitoring were within normal limits. Alveolus-capillary diffusion was within normal limits, although, in a second measurement of DLCO after 20 minutes of supine decubitus, the physiological increase that has been documented in normal subjects did not occur. Here we show how a reduction in post-ischemic vasodilation is correlated with increased oxidative stress indices, measured on serum and urine.
Conclusions: it could be speculated that a reduced compliance of the pulmonary circulation, in PNH patients, could be counted among the possible causes of exertional dyspnea independent of anemia.
Footnotes
Cite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 932.
This abstract was presented at the 2020 ERS International Congress, in session “Respiratory viruses in the "pre COVID-19" era”.
This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
- Copyright ©the authors 2020