Cystic fibrosis newborn screening: the importance of bloodspot sample quality.

OBJECTIVE: Wales has an immunoreactive trypsin (IRT)-DNA cystic fibrosis (CF) newborn screening (NBS) programme. Most CF NBS false negative cases are due to an IRT concentration below the screening threshold. The accuracy of IRT results is dependent on the quality of the dried bloodspot (DBS) sample. The aim of this study was to determine the cause of false negative cases in CF NBS and their relationship to DBS quality. DESIGN: Longitudinal birth cohort. SETTING: Wales 1996-2016. PATIENTS: Children with CF. INTERVENTIONS: Identification of all CF patients with triangulation of multiple data sources to detect false negative cases. MAIN OUTCOME MEASURES: False negative cases. RESULTS: Over 20 years, 673 952 infants were screened and 239 were diagnosed with CF (incidence 1:2819). The sensitivity of the programme was 0.958, and positive predictive value was 0.476. Eighteen potential false negatives were identified, of whom eight were excluded: four screened outside Wales, two had complex comorbidities, no identified cystic fibrosis transmembrane conductance regulator (CFTR) variants on extended analysis and thus not considered to have CF and two were diagnosed after their 16th birthday. Of the 10 false negatives, 9 had a low DBS IRT and at least one common CFTR variant and thus should have received a sweat test under the programme. DBS cards were available for inspection for five of the nine false negative cases-all were classified as small/insufficient or poor quality. CONCLUSIONS: The majority of false negatives had a low bloodspot IRT, and this was associated with poor quality DBS. The optimal means to improve the sensitivity of our CF NBS programme would be to improve DBS sample quality.

Risk factors for adverse outcome in infancy in meconium ileus cystic fibrosis infants: A multicentre Italian study.

BACKGROUND: Meconium ileus (MI) is a risk factor for poor outcomes in cystic fibrosis (CF) patients. The aim of this study was to identify the risk factors for poor 12-month clinical outcomes in MI-CF newborns. METHODS: This retrospective, multicentre, observational study of MI-CF infants born 2009-2015 recorded their pre- and neonatal histories, intestinal occlusion treatments, post-surgical history, nutrition, CF diagnosis, and compared the patients with 12-month faltering growth or chronic Pseudomonas aeruginosa respiratory infection (cases) with the others (controls). RESULTS: About 25% of the 85 patients enrolled by 13 Italian CF centres (24% premature, 18% of low birth weight) had prenatally diagnosed bowel obstruction, and 39% had complex MI. Seventy-one required surgery (the 33 with complex MI and 38 with simple MI), of whom 58 (82%) required post-surgical intensive care, including 25 (35%) needing ventilatory support. Forty-six (54%) were breastfed; exclusively parenteral nutrition was started in 52 (61%). Cholestasis was diagnosed in 21%. Thirty-one (37%) experienced negative outcomes: the only risk factors were prenatally diagnosed intestinal obstruction and a need for intensive care and oxygen therapy. The cases had significantly higher first blood immunoreactive trypsinogen (b-IRT) levels (P = .008). Logistic regression showed that the probability of having negative outcome is decreased in the absence of cholestasis (Odds Ratio = 0.125) and a need for intensive therapy (OR = 0.141), and increased by not having been breastfed (OR = 2.921). CONCLUSIONS: High b-IRT levels, prenatally diagnosed intestinal obstruction, a severe post-surgical clinical picture and early liver disease are risk factors for negative outcomes. Breastfeeding may be protective.

A safe and efficacious preventive strategy in the high-risk surgical neonate: cycled total parenteral nutrition.

INTRODUCTION: Hepatic dysfunction in patients reliant on total parenteral nutrition (TPN) may benefit from cycled TPN. A concern for neonatal hypoglycemia has limited the use of cycled TPN in neonates less than 1 week of age. We sought to determine both the safety and efficacy of cycled TPN in surgical neonates less than 1 week of age. METHODS: A retrospective chart review was conducted on surgical neonates placed on prophylactic and therapeutic cycled TPN from January 2013 to March 2016. Specific emphasis was placed on identifying incidence of direct hyperbilirubinemia and hypoglycemic episodes. RESULTS: Fourteen neonates were placed on cycled TPN; 8 were prophylactically cycled and 6 were therapeutically cycled. Median gestational age was 36 weeks (34, 37). Sixty-four percent (n = 9) had gastroschisis. There was no difference between the prophylactic and therapeutic groups in incidence of hyperbilirubinemia > 2 mg/dL (3 (37%) vs 5 (83%), p = 0.08) or the length of time to development of hyperbilirubinemia [24 days (4, 26) vs 27 days (25, 67), p = 0.17]. Time on cycling was similar though patients who were prophylactically cycled had a shorter overall time on TPN. Three (21%) infants had documented hypoglycemia, but only one infant became clinically symptomatic. CONCLUSION: Prophylactic TPN cycling is a safe and efficacious nutritional management strategy in surgical neonates less than 1 week of age with low rates of hypoglycemia and a shorter total course of TPN; however, hepatic dysfunction did not appear to be improved compared to therapeutic cycling.