Although the screened group had a higher proportion of patients with pancreatic insufficiency, their growth indices were significantly better than those of the control group during the 13-year follow-up evaluation and, therefore, this randomized clinical trial of early CF diagnosis must be interpreted as unequivocally positive. Our conclusions did not change when the height and weight data before 4 years of age for the controls detected by unblinding were included in the analysis. Also, comparison of growth outcomes after 4 years of age in all subjects showed persistence of the significant differences. Therefore, selection bias has been eliminated as a potential explanation. In addition, the results show that severe malnutrition persists after delayed diagnosis of CF and that catch-up may not be possible. We conclude that early diagnosis of CF through neonatal screening combined with aggressive nutritional therapy can result

As part of the ongoing Wisconsin Cystic Fibrosis (CF) Neonatal Screening Project, we had the unique opportunity to study the longitudinal relationship between Pseudomonas aeruginosa (Pa) acquisition and infection and developing lung disease in children with CF. The primary objective was to determine whether acquisition of Pa was associated with a measurable change in the progression of lung disease. Two outcome measures were used to study 56 patients who were diagnosed through newborn screening: 1) Wisconsin additive chest radiograph score (WCXR), based on the average of scores from a pulmonologist and a radiologist, and 2) the highest forced expired volume in 1 sec (FEV(1))/forced vital capacity (FVC) ratio. We used two measures of Pa acquisition: 1) time of first positive protocol-determined oropharyngeal (with cough) culture, and 2) the magnitude of antibody titer detected by ELISA assays, using as antigen a crude cell lysate, purified exotoxin A, or an elastase toxoid prepared from three Pa strains. Other predictor variables included age, pancreatic status, height-for age, and weight-for-age-percentiles. The best regression model for predicting changes in the WCXR included time to first positive culture and antibody titer for Pa elastase. Prior to Pa acquisition, WCXR worsened by 0.45 points/year (P > 0.25); after Pa acquisition, the rate of worsening increased significantly (P < 0.001) to 1.40 points/year. Each antibody titer level (log base 2) increased the score by 0.48 points (P < 0.001). The best regression model for predicting change in the FEV(1)/FVC included only time to first positive culture. Prior to Pa acquisition, the FEV(1)/FVC ratio declined by 1.29%/year; after Pa infection, the rate of decrease significantly accelerated to 1.81%/year (P = 0.001). Our data show that Pa acquisition is associated with declining pulmonary status in children with CF, and that this effect is probably gradual rather than precipitous. Because these patients were diagnosed and treated aggressively, our estimates of the effects of Pa acquisition may be conservative. We also conclude that the WCXR appears to be more sensitive than FEV(1)/FVC in detecting early changes in lung disease associated with CF.

Neonatal screening provides the opportunity to prevent malnutrition in infants with cystic fibrosis.

In CF patients diagnosed through neonatal screening, P aeruginosa pulmonary infections occurred 6 to 12 months before the organism was isolated from respiratory secretions. The longitudinal monitoring of P aeruginosa antibody titers, in concert with WCXR score, should facilitate diagnosis and treatment of P aeruginosa pulmonary infections in young children with CF.

Children with cystic fibrosis (CF) develop bronchopulmonary disease at variable ages. Determining the epidemiology of chronic lung disease and quantifying its severity, however, have been difficult in infants and young children. As part of the Wisconsin CF Neonatal Screening Project, we were presented with an ideal opportunity to assess longitudinally the evolution of symptoms, signs, and quantitative measures of CF respiratory disease. After newborn screening test results led to early recognition, 64 patients diagnosed at a median age of 6.71 weeks were enrolled and studied systematically at a median age of 11.3 years to obtain clinical information, chest radiographs, and pulmonary function tests. Our observations revealed that a frequent cough by history is evident by 10.5 months of age in half the patients. Quantitative chest radiology (CXR scoring) demonstrated that potentially irreversible abnormalities are present in half the children by 2 years. The severity of Wisconsin and Brasfield CXR scores increased in association with respiratory infections. Longitudinal progression of Wisconsin CXR scores was related to age (P < 0.001), pancreatic insufficiency (P = 0.005), and respiratory secretion cultures positive for Staphylococus aureas (P = 0.039). In contrast, serial spirometry showed limited sensitivity, as did lung volume determinations; neither was satisfactory as repeated measures with acceptable quality control until after 7 years of age. Time to event analyses revealed that half the patients had % predicted FEF(25-75) and FEV(1)/FVC values greater than 80% until 10.7 and 9.9 years, respectively. We conclude that of the methods evaluated, quantitative chest radiology is currently the best procedure for frequent assessment of bronchopulmonary disease in CF, and that radiographic progression is evident in approximately 85% of patients by 5 years of age. Our results also suggest that bronchiectasis and other radiographic evidence of chronic infection are apparent prior to airways obstruction in young CF patients.