Nitric oxide metabolism is altered during the acute chest syndrome of sickle cell disease. In the presence of oxygen and oxygen-related molecules, nitric oxide can preferentially form the powerful oxidants nitrite, nitrate, and peroxynitrite. We hypothesized that increased oxidative stress may contribute to the pathogenesis of acute chest syndrome and measured F2 isoprostanes, a nonenzymatically generated molecule resulting from free radical catalyzed lipid peroxidation in patients with sickle cell disease in various stages of disease. Plasma samples were obtained from nineteen patients with sickle cell disease during acute chest syndrome (pre- and postexchange transfusion), vasoocclusive crisis, and/or at baseline; 12 normal volunteers served as controls. F2 isoprostanes were measured by gas chromatography/mass spectrophotometry. There was a 9-fold increase in F2 isoprostanes in patients with acute chest syndrome as compared with normal volunteers. There was approximately a 50–60% decline in isoprostanes postexchange transfusion to a level similar to that of patients with sickle cell disease at baseline. There was no difference in isoprostanes between vasoocclusive crisis and patients with sickle cell disease at baseline. Increased oxidative stress, measured by generation of F2 isoprostanes, occurs during acute chest syndrome and may have an important role in the pathogenesis of this disease process.
Sensorineural hearing loss (SNHL) has been associated with sickle cell disease (SCD) in older children and adults. Few studies have investigated this association in younger children.In a cohort of pediatric patients followed at our sickle cell clinic, with a mean age of 7.8 years, 154 audiograms were completed on 84 patients.This produced 22 subjects with abnormal audiograms. Middle ear effusion was the etiology of 19 subjects' audiometric findings. Three children were found to have mild SNHL. None of the subjects had hearing loss of severity which would warrant amplification. The prevalence rate for SNHL in our cohort of pediatric patients was 3.5%.This differs from past reports, and may reflect an age dependent prevalence of SNHL in this disease.
