Immunoreactive trypsinogen in healthy newborns and infants with cystic fibrosis.

OBJECTIVE: Newborn screening (NBS) for cystic fibrosis (CF) was introduced in Switzerland in 2011 based on an immunoreactive trypsinogen (IRT)-DNA-IRT protocol. CF diagnosis was confirmed by sweat test and/or genetics but remained inconclusive for some newborns (cystic fibrosis transmembrane conductance regulator related metabolic syndrome (CRMS)/CF screen positive, inconclusive diagnosis (CFSPID)). We aimed to (1) Describe IRT levels in healthy newborns in the first year of life and by gestational age (GA), and (2) Compare IRT at two time points between healthy newborns and newborns with CF and CRMS/CFSPID. DESIGN: Retrospective study. SETTING: National NBS database. PATIENTS: All children with an IRT measurement by heel prick test from 2011 to 2019. INTERVENTIONS: None. MAIN OUTCOME MEASURES: IRT values were extracted from the National NBS Laboratory, and clinical characteristics of positively screened children from the CF-NBS database. Second IRT assessment in positively screened children was usually performed after 18-24 days. We calculated internal IRT Z-Scores and multiples of the median to compare our results across different laboratory tools. RESULTS: Among 815 899 children; 232 were diagnosed with CF, of whom 36 had meconium ileus (MI); 27 had CRMS/CFSPID. Among all samples analysed, mean IRT Z-Scores were higher for newborns with GA <33 weeks and ≥43 weeks (all Z-Scores >0.11) compared with term babies (all Z-Scores ≤0.06). Repeated IRT Z-Scores after a median (IQR) of 19 (17-22) days remained high for infants with CF with or without MI but decreased for infants with CRMS/CFSPID. CONCLUSIONS: Measurement of a second IRT value can help distinguish between children with CRMS/CFSPID and CF, early in life.

Prevalence of Pulmonary Embolism in Patients With Syncope.

BACKGROUND: The prevalence of pulmonary embolism (PE) in patients presenting with syncope to the emergency department (ED) is largely unknown. This information, however, is necessary to balance the potential medical benefit or harm of systematic PE screening in patients presenting with syncope to the ED. OBJECTIVES: This study sought to determine the prevalence of PE in patients with syncope. METHODS: Unselected patients presenting with syncope to the ED were prospectively enrolled in a diagnostic multicenter study. Pre-test clinical probability for PE was assessed using the 2-level Wells score and the results of D-dimer testing using age-adapted cutoffs. Presence of PE was evaluated by imaging modalities, when ordered as part of the clinical assessment by the treating ED physician or by long-term follow-up data. RESULTS: Long-term follow-up was complete in 1,380 patients (99%) at 360 days and 1,156 patients (83%) at 720 days. Among 1,397 patients presenting with syncope to the ED, PE was detected at presentation in 19 patients (1.4%; 95% confidence interval [CI]: 0.87% to 2.11%). The incidence of new PEs or cardiovascular death during 2-year follow-up was 0.9% (95% CI: 0.5% to 1.5%). In the subgroup of patients hospitalized (47%), PE was detected at presentation in 15 patients (2.3%; 95% CI: 1.4% to 3.7%). The incidence of new PEs or cardiovascular death during 2-year follow-up was 0.9% (95% CI: 0.4% to 2.0%). CONCLUSIONS: PE seems to be a rather uncommon cause of syncope among patients presenting to the ED. Therefore, systematic PE-screening in all patients with syncope does not seem warranted. (BAsel Syncope EvaLuation Study [BASEL IX]; NCT01548352).