Fifty-eight per cent of DS
children and 13% of non-DS children met criteria for acute lung injury. Similarly, 46% of DS children and 7% of non-DS children were diagnosed with acute respiratory distress syndrome (ARDS). None of the DS children in this cohort with acute lung injury died, whereas others have reported a mortality rate of about 5% of non-DS children with ARDS. These data suggest that children with DS have an increased risk of progressing towards ARDS, although with low mortality, and support the hypothesis of Vincristine abnormal regulatory mechanisms of inflammation, such as an imbalance of anti-oxidants and oxidative stress [19], which might lead to apoptosis in lung tissue. A review of a large cohort of DS children in Sweden and Denmark [20] revealed a 12-times increased risk for mortality due to infections, especially septicaemia. This excess of mortality was consistent with data from a recent study in which DS children showed a 30% higher risk of fatality secondary to sepsis when compared to other children hospitalized for sepsis [21], after controlling for confounding factors including pathogens and co-morbid conditions. The above studies highlight the increased frequency and severity of respiratory tract
infections Saracatinib supplier in DS children. These are predominantly ear infections; however, pneumonias occur frequently in children younger than 5 years of age and are likely to require hospitalization. Lung disease might be of more prolonged duration and might progress to ARDS. In addition to respiratory tract infections, periodontal disease is another condition of infectious aetiology that occurs frequently between
58% and 96% of individuals with DS [22]. Due to the complexity of the pathophysiology of gingivitis, the contributions of potential determinant factors such as abnormal immunity and poor oral hygiene have not yet been defined clearly. Defects in immunological parameters in DS have been described and postulated as explanations for the increased severity of infections Chloroambucil seen in DS children [9,10]. Most of these infections are of the respiratory tract, suggesting abnormalities of the humoral immunity. However, differences in several compartments of the immune response have been reported [23–25] (Table 1). Reduced ranges of the different lymphocyte subsets were found to be of most significance in childhood, with subsequent improvement over age. T and B cell subsets are decreased below the 10th percentile of normal in almost 90% of DS children, and below the 5th percentile of normal in 60% of them. The normal early T cell expansion in infancy was not observed. Their thymus size was reported to be smaller than non-DS children, with decreased T cell percentages bearing the T cell receptor (TCR)-αβ and relatively reduced naive T cell percentages [26–28], resulting in mild to moderate lymphopenia.