Objective: To evaluate the relationship between ciliary ultrastructure/genotype and prevalence of neonatal respiratory distress in primary ciliary dyskinesia (PCD). Study Design: This was a retrospective analysis from a multicenter, prospective study of children and adults with PCD. Participants were classified by ultrastructural defect associated with their diagnostic genetic variants: 1) outer dynein arm defect alone (ODA), 2) outer plus inner dynein arm defect (ODA/IDA), 3) inner dynein arm defect with microtubular disorganization (IDA/MTD), 4) DNAH11 (encodes ODA protein but has normal ultrastructure), and 5) normal/near normal/other. The likelihood of neonatal respiratory distress between ultrastructure groups or genotypes was evaluated by multivariate analysis using logistic regression, controlled for age, gender, race, and variant type. Similar analysis was performed within individual genotypes to assess association of neonatal respiratory distress with the presence of 2 loss-of-function variants. Results: Of the 455 participants analyzed, 305 (67.0%) reported neonatal respiratory distress. The odds ratio for neonatal respiratory distress in the DNAH11 group was significantly lower (OR 0.35, 95% CI 0.16-0.76) compared to neonatal respiratory distress in the ODA group. Within the DNAH5 group, those with 2 loss-of-function variants were more likely to have neonatal respiratory distress compared to those with possible residual function variants (OR 3.06, 95% CI 1.33-7). Conclusion: Neonatal respiratory distress is less common in those with DNAH11 variants, thus a high index of suspicion should remain for PCD in the absence of neonatal respiratory distress.

ABSTRACT Background: The goal of this study was to identify clinical features associated with abnormal infant pulmonary function tests (iPFTs), specifically functional residual capacity (FRC), in infants with cystic fibrosis (CF) diagnosed via newborn screen (NBS). We hypothesized that poor nutritional status in the first 6-12 months would be associated with increased FRC at 12-24 months. Methods: This study utilized a combination of retrospectively and prospectively collected data from ongoing research studies and iPFTs performed for clinical indications. Demographic and clinical features were obtained from the electronic medical record. Forced expiratory flows and volumes were obtained using the raised volume rapid thoracoabdominal technique (RVRTC) and FRC was measured via plethysmography. Results: A total of 45 CF NBS infants had iPFTs performed between 12-24 months. Mean forced vital capacity, forced expiratory volume in 0.5 second, and forced expiratory flows were all within normal limits. In contrast, the mean FRC z-score was 2.18 (95%CI=1.48, 2.88) and the mean respiratory rate (RR) z-score was 1.42 (95%CI=0.95, 1.89). There was no significant association between poor nutritional status and abnormal lung function. However, there was a significant association between higher RR and increased FRC, and a RR cutoff of 36 breaths/min resulted in 92% sensitivity to detect hyperinflation with 32% specificity. Conclusions: These results suggest that FRC is a more sensitive measure of early CF lung disease than RVRTC measurements and that RR may be a simple, non-invasive clinical marker to identify CF NBS infants with hyperinflation.

Introduction: The Lung Clearance Index (LCI) derived from the multiple-breath washout test (MBW), is both feasible and sensitive to early lung disease detection in young children with cystic fibrosis and asthma. The utility of LCI has not been studied in children with sickle cell disease (SCD). We hypothesized that children with SCD, with or without asthma or airway hyper reactivity (AHR), would have an elevated LCI compared to healthy controls. Methods: Children with SCD from a single center between the ages of 6-18 years were studied at baseline health and completed MBW, spirometry, plethysmography and blood draws for serum markers. Results were compared to healthy controls of similar race, age and gender. Results: Control subjects (n=35) had a significantly higher daytime oxygen saturation level, weight and body mass index (BMI) but not height compared to subjects with SCD (n=34). Total Lung Capacity(TLC) z-scores were significantly higher in the healthy controls compared to those with SCD (0.87 (1.13), 0.02 (1.27), p=0.005) while differences in Forced Expiratory Volume in 1 second (FEV1) z-scores approached significance (0.26 (0.97), -0.22 (1.09), p=0.055). There was no significant difference in LCI among the comparison groups (7.29 (0.72), 7.40 (0.69), p=0.514). Conclusion: LCI did not differentiate SCD from healthy controls in children between the ages of 6 and 18 years at baseline health. TLC may be an important pulmonary function measure to follow longitudinally in the pediatric SCD population.