Decreased nitrite reductase activity of deoxyhemoglobin correlates with platelet activation in hemoglobin E/ß-thalassemia subjects.

Nitric oxide (NO) can be generated from nitrite by reductase activity of deoxygenated hemoglobin (deoxyHb) apparently to facilitate tissue perfusion under hypoxic condition. Although hemoglobin E (HbE) solutions have been shown to exhibit decreased rate of nitrite reduction to NO, this observation has never been reported in erythrocytes from subjects with hemoglobin E/ß-thalassemia (HbE/ß-thal). In this study, we investigated the nitrite reductase activity of deoxyHb dialysates from 58 non-splenectomized and 23 splenectomized HbE/ß-thal subjects compared to 47 age- and sex-matched normal subjects, and examined its correlation with platelet activity.

Inhaled nebulized sodium nitrite decreases pulmonary artery pressure in β-thalassemia patients with pulmonary hypertension.

Pulmonary hypertension is a life-threatening complication in β-thalassemia. Inhaled sodium nitrite has vasodilatory effect on pulmonary vasculature. However, its effect on pulmonary artery pressure (PAP) in β-thalassemia subjects with pulmonary hypertension has never been reported.