Lung T1 MRI assessments in children with mild cystic fibrosis lung disease.

RATIONALE: Lung T1 MRI is a potential method to assess cystic fibrosis (CF) lung disease that is safe, quick, and widely available, but there are no data in children with mild CF lung disease. OBJECTIVE: Assess the ability of lung T1 MRI to detect abnormalities in children with mild CF lung disease. METHODS: We performed T1 MRI, multiple breath washout (MBW), chest computed tomography (CT), and spirometry in a cohort of 45 children with mild CF lung disease (6-11 years of age). MAIN RESULTS: Despite mean normal ppFEV1 values, the majority of children with CF in this study exhibited mild lung disease evident in lung clearance index (LCI) measured by MBW, chest CT Brody scores, and percent normal lung perfusion (%NLP) measured by T1 MRI. The %NLP correlated with chest CT Brody scores, as did LCI, but %NLP and LCI did not correlate with each other. Analysis of the Brody subscores showed that %NLP and LCI largely correlated with different Brody subscores. CONCLUSIONS: T1 MRI can detect mild CF lung disease in children and correlates with chest CT findings. The %NLP from T1 MRI and LCI correlate with different chest CT Brody subscores, suggesting they provide complementary information about CF lung disease.

Cystic Fibrosis Foundation Evidence-Based Guideline for the Management of CRMS/CFSPID.

A multidisciplinary committee developed evidence-based guidelines for the management of cystic fibrosis transmembrane conductance regulator-related metabolic syndrome/cystic fibrosis screen-positive, inconclusive diagnosis (CRMS/CFSPID). A total of 24 patient, intervention, comparison, and outcome questions were generated based on surveys sent to people with CRMS/CFSPID and clinicians caring for these individuals, previous recommendations, and expert committee input. Four a priori working groups (genetic testing, monitoring, treatment, and psychosocial/communication issues) were used to provide structure to the committee. A systematic review of the evidence was conducted, and found numerous case series and cohort studies, but no randomized clinical trials. A total of 30 recommendations were graded using the US Preventive Services Task Force methodology. Recommendations that received ≥80% consensus among the entire committee were approved. The resulting recommendations were of moderate to low certainty for the majority of the statements because of the low quality of the evidence. Highlights of the recommendations include thorough evaluation with genetic sequencing, deletion/duplication analysis if <2 disease-causing variants were noted in newborn screening; repeat sweat testing until at least age 8 but limiting further laboratory testing, including microbiology, radiology, and pulmonary function testing; minimal use of medications, which when suggested, should lead to shared decision-making with families; and providing communication with emphasis on social determinants of health and shared decision-making to minimize barriers which may affect processing and understanding of this complex designation. Future research will be needed regarding medication use, antibiotic therapy, and the use of chest imaging for monitoring the development of lung disease.

Clinical outcomes at 9-10 years of age in children born with cystic fibrosis transmembrane conductance regulator related metabolic syndrome.

BACKGROUND AND OBJECTIVES: There are limited data on cystic fibrosis (CF) transmembrane conductance regulator-related metabolic syndrome (CRMS) outcomes beyond infancy. The goal of this study was to analyze outcomes of infants with CRMS up to the age of 9-10 years using the CF Foundation Patient Registry (CFFPR). METHODS: We analyzed data from the CFFPR for individuals with CF and CRMS born between 2010 and 2020. We classified all patients based on the clinical diagnosis reported by the CF care center and the diagnosis using CFF guideline definitions for CF and CRMS, classifying children into groups based on agreement between clinical report and guideline criteria. Descriptive statistics for the cohort were calculated for demographics, nutritional outcomes, and microbiology for the first year of life and lung function and growth outcomes were summarized for ages 6-10 years. RESULTS: From 2010 to 2020, there were 8765 children with diagnosis of CF or CRMS entered into the CFFPR with sufficient diagnostic data for classification, of which 7591 children had a clinical diagnosis of CF and 1174 had a clinical diagnosis of CRMS. CRMS patients exhibited normal nutritional indices and pulmonary function up to age 9-10 years. The presence of respiratory bacteria associated with CF, such as Pseudomonas aeruginosa from CRMS patients ranged from 2.1% to 9.1% after the first year of life. CONCLUSIONS: Children with CRMS demonstrate normal pulmonary and nutritional outcomes into school age. However, a small percentage of children continue to culture CF-associated respiratory pathogens after infancy.

Decreased vascular reactivity associated with increased IL-8 in 6-month-old infants of mothers with pre-eclampsia.

BACKGROUND: Offspring born to mothers with pre-eclampsia (Pre-E) suffer higher risks of adult cardiovascular diseases, suggesting that exposure to an antiangiogenic environment in-utero has a lasting impact on the development of endothelial function. The goal of this study is to test the hypothesis that in-utero exposure to Pre-E results in alterations of angiogenic factors/cytokines that negatively impact vascular development during infancy. METHODS: Infants born from mothers with and without Pre-E were recruited and followed up at 6 months. Plasma cytokines, blood pressure, microvessel density, and vascular reactivity were assessed. RESULTS: 6-month-old infants born to mothers with Pre-E had unchanged blood pressure (p = 0.86) and microvessel density (p = 0.57). Vascular reactivity was decreased in infants born to mothers with Pre-E compared to infants born to healthy mothers (p = 0.0345). Interleukin 8 (IL-8) (p = 0.03) and Angiopoeitin-2 (Ang-2) (p = 0.04) were increased in infants born to mothers with Pre-E. We observed that higher IL-8 was associated with lower vascular reactivity (rho = -0.14, p < 0.0001). CONCLUSION: At 6 months of age, infants born to mothers with Pre-E had impaired vascular reactivity and higher IL-8 and Ang-2, but similar blood pressure and microvessel density compared to infants born to non-Pre-E mothers. IMPACT STATEMENT: Changes in cord blood antiangiogenic factors are documented in infants of mothers with pre-eclampsia and may contribute to offspring risks of adult cardiovascular disease. How these factors evolve during early infancy and their correlation with offspring vascular development have not been studied. This study found that 6-month-old infants born to mothers with pre-eclampsia had decreased vascular reactivity, which was correlated with higher IL-8. These findings underscore the lasting impact of maternal pre-eclampsia on offspring vascular development and highlight the need for long-term follow-up in children born to mothers with pre-eclampsia.

Pediatric pulmonology year in review 2023: Physiology.

Application of the principles of pulmonary physiology and lung development to the care and management of respiratory disease in children is a distinguishing feature of pediatric pulmonology. In 2023, this was evident in numerous publications in Pediatric Pulmonology and other journals. This review will highlight some of the papers in this area.

Clinical features associated with pulmonary exacerbation diagnosis in infants and young children with cystic fibrosis.

RATIONALE: Diagnosing cystic fibrosis (CF) pulmonary exacerbations (PEx) in very young people with CF <3 years (VY-PwCF) is challenging because of the frequency of respiratory viral infections in this age group, and there are limited data on the clinical features associated with the diagnosis of PEx in this age group. The goal of this study was to identify clinical features associated with the diagnosis of PEx in VY-PwCF. METHODS: We reviewed the medical records of VY-PwCF followed at the Children's Hospital of Philadelphia born between 2013 and 2019. We collected data from all encounters with respiratory symptoms. PEx was defined by treatment with oral or intravenous antibiotics. Clinical features of PEx and non-PEx encounters were compared using descriptive statistics, and odds ratios of PEx diagnosis were calculated. RESULTS: A total of 78 patients were included in the analysis. The mean (SD) number of PEx per patient was 6.17 (5.88). The presence of a wet or nighttime cough and symptoms >3 days in duration were significantly associated with PEx diagnosis (p < .001). In contrast, symptoms such as sore throat or rhinorrhea were not associated with a higher likelihood of PEx. CONCLUSIONS: The presence of a wet or night-time cough and longer symptom duration are common features of PEx in VY-PwCF, whereas symptoms suggestive of upper respiratory viral infection are not. Our results will be helpful in counseling families of VY-PwCF in the signs and symptoms of PEx and in planning future research in PEx in this age group.

Late Diagnosis in the Era of Universal Newborn Screening Negatively Affects Short- and Long-Term Growth and Health Outcomes in Infants with Cystic Fibrosis.

Newborn screening for cystic fibrosis was fully implemented in the US by 2010, but delays in timeliness of evaluation for infants with positive newborn screening tests persist. Through evaluation of national patient registry data, we determined that late initiation of cystic fibrosis care is associated with poorer long-term nutritional outcomes.

Antibiotic Regimen Changes during Cystic Fibrosis Pediatric Pulmonary Exacerbation Treatment.

Rationale/Objectives: Antibiotic selection for in-hospital treatment of pulmonary exacerbations (PEx) in people with cystic fibrosis (CF) is typically guided by previous respiratory culture results or past PEx antibiotic treatment. In the absence of clinical improvement during PEx treatment, antibiotics are frequently changed in search of a regimen that better alleviates symptoms and restores lung function. The clinical benefits of changing antibiotics during PEx treatment are largely uncharacterized. Methods: This was a retrospective cohort study using the Cystic Fibrosis Foundation Patient Registry Pediatric Health Information System. PEx were included if they occurred in children with CF from 6 to 21 years old who had been treated with intravenous antibiotics between January 1, 2006, and December 31, 2018. PEx with lengths of stay <5 or >21 days or for which treatment was delivered in an intensive care unit were excluded. An antibiotic change was defined as the addition or subtraction of any intravenous antibiotic between Hospital Day 6 and the day before hospital discharge. Inverse probability of treatment weighting was used to adjust for disease severity and indication bias, which might influence a decision to change antibiotics. Results: In all, 4,099 children with CF contributed 18,745 PEx for analysis, of which 8,169 PEx (43.6%) included a change in intravenous antibiotics on or after Hospital Day 6. The mean change in pre- to post-treatment percent predicted forced expiratory volume in 1 second (ppFEV1) was 11.3 (standard error, 0.21) among events in which an intravenous antibiotic change occurred versus 12.2 (0.18) among PEx without an intravenous antibiotic change (P = 0.001). Similarly, the odds of return to ⩾90% of baseline ppFEV1 were less for PEx with antibiotic changes than for those without changes (odds ratio [OR], 0.89 [95% confidence interval (CI), 0.80-0.98]). The odds of returning to ⩾100% of baseline ppFEV1 did not differ between PEx with versus without antibiotic changes (OR, 0.94 [95% CI, 0.86-1.03]). In addition, PEx treated with intravenous antibiotic changes were associated with higher odds of future PEx (OR, 1.17 [95% CI, 1.12-1.22]). Conclusions: In this retrospective study, changing intravenous antibiotics during PEx treatment in children with CF was common and not associated with improved clinical outcomes.

Pediatric pulmonology year in review 2021 and 2022: Physiology.

Pulmonary physiology is a core element of pediatric pulmonology care and research. This article reviews some of the notable publications in physiology that were published in Pediatric Pulmonology in 2021 and 2022.

Variation in cystic fibrosis newborn screening algorithms in the United States.

RATIONALE: Cystic fibrosis (CF) newborn screening (NBS) algorithms in the United States vary by state. Differences in CF NBS algorithms could potentially affect the detection rate of CF newborns and lead to disparities in CF diagnosis amongst different racial and ethnic groups. OBJECTIVES: Generate a database of CF NBS algorithms in the United States and identify processes that may potentially lead to missed diagnoses or lead to healthcare disparities. METHODS: We sent an online survey to state and regional CF and NBS leaders about the type and threshold of immunoreactive trypsinogen (IRT) cutoff used and methods used for CFTR  gene variant analysis. Follow-up by email and phone was done to ensure a response from every state, clarify responses, and resolve discordances. RESULTS: There is wide variation in the NBS algorithms employed by different states. Approximately half the states use a floating IRT cutoff, and half use a fixed IRT cutoff. CFTR variant analysis also varies widely, with two states analyzing only for the F508del variant and four states incorporating CFTR gene sequencing. The other states use CFTR variant panels ranging from 23 to 365 CFTR variants. CONCLUSIONS: CF NBS algorithms vary widely amongst the different states in the United States, which affects the ability of CF NBS to diagnose newborn infants with CF consistently and uniformly across the country and potentially may miss more infants with CF from minority populations. Our results identify an important area for quality improvement in CF NBS.

Detection of disease-causing CFTR variants in state newborn screening programs.

BACKGROUND: Newborn screening (NBS) algorithms for cystic fibrosis (CF) vary in the United State of America and include different cystic fibrosis transmembrane conductance regulator (CFTR) variants. CFTR variant distribution varies among racial and ethnic groups. OBJECTIVE: Our objectives were to identify differences in detection rate by race and ethnicity for CFTR variant panels, identify each US state detection rate for CFTR variant panels, and describe the rate of false-negative NBS and delayed diagnoses by race and ethnicity. METHODS: This is a cross-sectional analysis of the detection rate of at least 1 CFTR variant for seven panels by race and ethnicity in genotyped people with CF (PwCF) or CFTR-related metabolic syndrome (CRMS)/CFTR-related disorders in CF Foundation Patient Registry (CFFPR) in 2020. We estimated the case detection rate of CFTR variant panels by applying the detection rate to Census data. Using data from CFFPR, we compared the rate of delayed diagnosis or false-negative NBS by race and ethnicity. RESULTS: For all panels, detection of at least 1 CFTR variant was highest in non-Hispanic White PwCF (87.5%-97.0%), and lowest in Black, Asian, and Hispanic PwCF (41.9%-93.1%). Detection of at least 1 CFTR variant was lowest in Black and Asian people with CRMS/CFTR-related disorders (48.4%-64.8%). States with increased racial and ethnic diversity have lower detection rates for all panels. Overall, 3.8% PwCF had a false-negative NBS and 11.8% had a delayed diagnosis; Black, Hispanic, and mixed-race PwCF were overrepresented. CONCLUSION: CFTR variant panels have lower detection rates in minoritized racial and ethnic groups leading to false-negative NBS, delayed diagnosis, and likely health disparities.

Disparities in first evaluation of infants with cystic fibrosis since implementation of newborn screening.

OBJECTIVE: We evaluated whether implementation of cystic fibrosis (CF) newborn screening (NBS) leads to equitable timeliness of initial evaluation. We compared age at first event (AFE, age at sweat test, encounter and/or care episode) between infants categorized as Black/African American, American Indian/ Native Alaskan, Asian, and/or Hispanic and/or other (Group 1) to White and not Hispanic infants (Group 2). METHODS: This retrospective cohort study from the Cystic Fibrosis Foundation Patient Registry (CFFPR) included infants born 2010-2018. Race and ethnicity categories followed US Census definitions. The primary outcome was AFE; the secondary outcome was weight for age (WFA) z-score averaged 12 to < 24 months. We compared distributions by Wilcoxon rank-sum test and proportions by Chi-square or Fisher's exact tests. A nested cohort study used a linear mixed effects model of variables that affect WFA, chosen a priori, to evaluate associations with 1-year WFA z-score. RESULTS: Among 6354 infants, 21% were in Group 1. Group 1 median AFE was 31 days (IQR 19, 49) and Group 2 was 22 days (IQR 14,36) (p< .001). Median WFA z-score at 1-2 years was lower in Group 1. In 3017 infants with complete data on variables of interest, AFE, Black race, CFTR variant class I-III, prematurity and public insurance were associated with lower 1-year WFA z-score. CONCLUSIONS: Differences in AFE for infants with CF from historically marginalized groups may exacerbate long standing health disparities. We speculate that inequitable identification of CFTR gene variants and/or bias may influence timeliness of evaluation after an out-of-range NBS.

Real-world Associations of US Cystic Fibrosis Newborn Screening Programs With Nutritional and Pulmonary Outcomes.

Importance: Newborn screening (NBS) for cystic fibrosis (CF) has been universal in the US since 2010, but its association with clinical outcomes is unclear. Objective: To describe the real-world effectiveness of NBS programs for CF in the US on outcomes up to age 10 years. Design, Setting, and Participants: This was a retrospective cohort study using CF Foundation Patient Registry data from January 1, 2000, to December 31, 2018. The staggered implementation of NBS programs by state was used to compare longitudinal outcomes among children in the same birth cohort born before vs after the implementation of NBS for CF in their state of birth. Participants included children with an established diagnosis of CF born between January 1, 2000, to December 31, 2018, in any of the 44 states that implemented NBS for CF between 2003 and 2010. Data were analyzed from October 5, 2020, to April 22, 2022. Exposures: Birth before vs after the implementation of NBS for CF in the state of birth. Main Outcomes and Measures: Longitudinal trajectory of height and weight percentiles from diagnosis, lung function (forced expiratory volume in 1 second, [FEV1] percent predicted) from age 6 years, and age at initial and chronic infection with Pseudomonas aeruginosa using linear mixed-effects and time-to-event models adjusting for birth cohort and potential confounders. Results: A total of 9571 participants (4713 female participants [49.2%]) were eligible for inclusion, with 4510 (47.1%) in the pre-NBS cohort. NBS was associated with higher weight and height percentiles in the first year of life (weight, 6.0; 95% CI, 3.1-8.4; height, 6.6; 95% CI, 3.8-9.3), but these differences decreased with age. There was no association between NBS and FEV1 at age 6 years, but the percent-predicted FEV1 did increase more rapidly with age in the post-NBS cohort. NBS was associated with older age at chronic P aeruginosa infection (hazard ratio, 0.69; 95% CI, 0.54-0.89) but not initial P aeruginosa infection (hazard ratio, 0.88; 95% CI, 0.77-1.01). Conclusions and Relevance: NBS for CF in the US was associated with improved nutritional status up to age 10 years, a more rapid increase in lung function, and delayed chronic P aeruginosa infection. In the future, as highly effective modulator therapies become available for infants with CF, NBS will allow for presymptomatic initiation of these disease-modifying therapies before irreversible organ damage.

Newborn Screening for Cystic Fibrosis: A Qualitative Study of Successes and Challenges from Universal Screening in the United States.

Cystic fibrosis (CF) newborn screening (NBS) was universally adopted in 2009 in the United States. Variations in NBS practices between states may impact the timing of diagnosis and intervention. Quantitative metrics can provide insight into NBS programs (NBSP), but the nuances cannot be elucidated without additional feedback from programs. This study was designed to determine facilitators and barriers to timely diagnosis and intervention following NBS for CF. The median age at the first CF event for infants with CF within each state was used to define early and late states (n = 15 per group); multiple CF centers were invited in states with more than two CF centers. Thirty states were eligible, and 61 NBSP and CF centers were invited to participate in structured interviews to determine facilitators and barriers. Once saturation of themes was reached, no other interviews were conducted. Forty-five interviews were conducted (n = 16 early CF center, n = 12 late CF center, n = 11 early NBSP, and n = 6 late NBSP). Most interviewees reported good communication between CF centers and NBSP. Communication between primary care providers (PCPs) and families was identified as a challenge, leading to delays in referral and subsequent diagnosis. The misperception of low clinical risk in infants from racial and ethnic minority groups was a barrier to early diagnostic evaluation for all groups. NBSP and CF centers have strong relationships. Early diagnosis may be facilitated through more engagement with PCPs. Quality improvement initiatives should focus on continuing strong partnerships between CF centers and NBS programs, improving education, communication strategies, and partnerships with PCPs, and improving CF NBS timeliness and accuracy.

Forced expiratory flows and diffusion capacity in infants born from mothers with pre-eclampsia.

RATIONALE: Animal models suggest pre-eclampsia (Pre-E) affects alveolar development, but data from humans are lacking. OBJECTIVE: Assess the impact of Pre-E on airway function, diffusion capacity, and respiratory morbidity in preterm and term infants born from mothers with Pre-E. METHODS: Infants born from mothers with and without Pre-E were recruited for this study; term and preterm infants were included in both cohorts. Respiratory morbidity in the first 12 months of life was assessed through monthly phone surveys. Raised volume rapid thoracoabdominal compression and measurement of diffusion capacity of the lung to carbon monoxide (DLCO) were performed at 6 months corrected age. MEASUREMENTS AND MAIN RESULTS: There were 146 infants in the Pre-E cohort and 143 in the control cohort. The Pre-E cohort was further divided into nonsevere (N = 41) and severe (N = 105) groups. There was no significant difference in DLCO and DLCO/alveolar volume among the three groups. Forced vital capacity was similar among the three groups, but the nonsevere Pre-E group had significantly higher forced expiratory flows than the other two groups. After adjusting for multiple covariates including prematurity, the severe Pre-E group had a lower risk for wheezing in the first year of life compared to the other two groups. CONCLUSIONS: Pre-E is not associated with reduced DLCO, lower forced expiratory flows, or increased wheezing in the first year of life. These results differ from animal models and highlight the complex relationships between Pre-E and lung function and respiratory morbidity in human infants.

Evaluating FEV1 decline in diagnosis and management of pulmonary exacerbations in children with cystic fibrosis.

RATIONALE: Forced expiratory volume in 1 s (FEV1) decline (ΔFEV1) is associated with pulmonary exacerbation (PEx) diagnosis in cystic fibrosis (CF). Spirometry may not be available during telehealth visits and could impair clinician ability to diagnose PEx. This study aims to (1) identify the associations between degrees of ΔFEV1 (decrease of <5% predicted vs. 5%-9% predicted vs. ≥10% predicted from baseline), clinical symptoms, and clinician-diagnosed PEx and (2) evaluate the correlation between respiratory symptoms, ΔFEV1, and antibiotic treatment. METHODS: Retrospective, descriptive study of PEx diagnosis and management in 628 outpatient clinical encounters with spirometry in 178 patients with CF ages 6-17 years at Riley Hospital for Children during 2019. Odds ratios (OR) of symptoms associated with clinician-defined PEx diagnosis and antibiotic management stratified by ΔFEV1 decline were determined. RESULTS: Clinician-diagnosed PEx occurred at 199 (31.7%) visits; increased cough (77.4%) and sputum/wet cough (57.8%) were the most frequently reported symptoms. Compared to no ΔFEV1, the odds of a clinician-diagnosed PEx were increased when ΔFEV15%-9% and ΔFEV1≥10% was present with increased cough (OR 1.56, 95% confidence interval [CI] 1.25-1.94 and OR 1.82, 95% CI 1.52-2.19, respectively), increased sputum (OR 1.59, 95% CI 1.20-2.12 and OR 1.78, 95% CI 1.37-2.32, respectively), and increased cough and sputum together (OR 1.51, 95% CI 1.08-2.13 and OR 1.68, 95% CI 1.22-2.31, respectively). CONCLUSIONS: ΔFEV1 is associated with increased likelihood that cough and sputum are diagnosed as a PEx. Spirometry is essential for PEx diagnosis and treatment and is a necessary component of all clinical encounters.

Changes in Care during the COVID-19 Pandemic for People with Cystic Fibrosis.

Rationale: Cystic fibrosis (CF) centers transitioned to telemedicine during the spring 2020 peak of the coronavirus disease (COVID-19) pandemic. Objectives: We hypothesized that people with CF (pwCF) with more severe disease would be more likely to be seen in-person. Methods: We used paired t tests to compare within-subject changes in body mass index (BMI) and percentage predicted forced expiratory volume in one second (FEV1) and calculated relative risk (RR) to compare pulmonary exacerbations (PEx) between pwCF enrolled in the CF Foundation Patient Registry with at least one in-person clinic visit after March 15 in both 2019 and 2020. Results: Overall, the proportion of clinical encounters that were in-person clinic visits decreased from 91% in 2019 to a low of 9% in April 2020. Among pwCF seen after March 15 in both 2019 and 2020, the mean (95% confidence interval [CI]) FEV1 percentage predicted was 1.3% (0.1-2.4) predicted higher in 2020 for children 6 to <12 years of age, and 7.5% (7.1-7.9) predicted higher in 2020 among pwCF ⩾12 years of age eligible for the highly effective CF transmembrane conductance regulator modulator, elexacaftor-tezacaftor-ivacaftor (ETI). There was no difference in FEV1 percentage predicted for pwCF ⩾12 years of age who were not eligible for ETI. Similarly, the mean (95% CI) BMI was 2.4 (2.0-2.8) percentile higher in 2020 for children 6 to <12 years of age and 5.2 (4.8-5.7) percentile higher in 2020 among children 12 to <18 years of age eligible for ETI. Mean (95% CI) BMI was 1.2 (1.2-1.3) (kg/m2) higher for pwCF ⩾18 years of age eligible for ETI, and 0.2 (0.1-0.3) (kg/m2) higher for pwCF ⩾18 years of age not eligible for ETI. The proportion of in-person clinic visits where any PEx was present was lower in 2020 compared with 2019, 25% compared with 38%, RR 0.82 (0.79-0.86). Conclusions: The care of pwCF was substantially changed during the spring 2020 peak of the COVID-19 pandemic. Among pwCF seen in-person in both 2019 and 2020 after the spring peak of the COVID-19 pandemic, lung function and BMI were higher in 2020 for children 6 to <12 years of age and pwCF eligible for ETI.

Nutritional status and lung function in children with pancreatic-sufficient cystic fibrosis.

BACKGROUND: There is a strong association between nutrition and long-term FEV1 in cystic fibrosis (CF), but studies have been driven by data from subjects with pancreatic insufficiency (PI-CF). We thus evaluated the association between body mass index (BMI) and FEV1 percent-predicted (FEV1pp) in children with pancreatic sufficiency (PS-CF) and contrasted it with the association in PI-CF. METHODS: We utilized data from the CF Foundation Patient Registry. The cohort included children born 1995-2010, diagnosed <2 years of age, and who had annualized data on BMI percentile and FEV1pp at ages 6-16 years. Pancreatic status was defined based on pancreatic enzyme replacement therapy. The association between BMI and FEV1 was evaluated using linear and mixed-effects longitudinal regression. RESULTS: There were 424 children with PS-CF and 7,849 with PI-CF. The association between BMI and FEV1 differed significantly by pancreatic status: each 10-pct higher BMI was associated with 2% [95%CI = 1.9-2.1] higher FEV1pp in PI-CF, compared to just 0.9% [0.5-1.3] in PS-CF (PINTERACTION < 0.001). Within the at-risk nutritional category (BMI <25pct), each 10-pct higher BMI was associated with 5% higher FEV1pp in PI-CF, but no significant increase in PS-CF. Moreover, in PS-CF, overweight/obesity (BMI ≥85pct) was associated with decreasing FEV1pp. In addition, FEV1pp decline through age 20 years in youth with PS-CF was modest (-0.6% per year) and independent of BMI (BMI*age PINTERACTION = 0.37). CONCLUSIONS: In children with PS-CF, BMI remains an important determinant of lung function. However, it may be less critical to attain a BMI >50th percentile; and BMI ≥85th percentile may be detrimental.

International Approaches to Management of CFTR-Related Metabolic Syndrome/Cystic Fibrosis Screen Positive, Inconclusive Diagnosis.

The main aim of the present study was to explore health professionals' reported experiences and approaches to managing children who receive a designation of cystic fibrosis transmembrane conductance regulator-related metabolic syndrome/cystic fibrosis screen positive inconclusive diagnosis following a positive NBS result for cystic fibrosis. An online questionnaire was distributed via Qualtrics Survey Software and circulated to a purposive, international sample of health professionals involved in managing children with this designation. In total, 101 clinicians completed the online survey: 39 from the US, six from Canada, and 56 from Europe (including the UK). Results indicated that while respondents reported minor deviations in practice, they were cognizant of recommendations in the updated guidance and for the most part, attempted to implement these into practice consistently internationally. Where variation was reported, the purpose of this appeared to be to enable clinicians to respond to either clinical assessments or parental anxiety in order to improve outcomes for the child and family. Further research is needed to determine if these findings are reflective of both a wider audience of clinicians and actual (rather than reported) practice.