Impact of newborn screening on outcomes and social inequalities in cystic fibrosis: a UK CF registry-based study

Current Status of Newborn Bloodspot Screening Worldwide 2024: A Comprehensive Review of Recent Activities (2020-2023)

Newborn bloodspot screening (NBS) began in the early 1960s based on the work of Dr. Robert "Bob" Guthrie in Buffalo, NY, USA. His development of a screening test for phenylketonuria on blood absorbed onto a special filter paper and transported to a remote testing laboratory began it all. Expansion of NBS to large numbers of asymptomatic congenital conditions flourishes in many settings while it has not yet been realized in others. The need for NBS as an efficient and effective public health prevention strategy that contributes to lowered morbidity and mortality wherever it is sustained is well known in the medical field but not necessarily by political policy makers. Acknowledging the value of national NBS reports published in 2007, the authors collaborated to create a worldwide NBS update in 2015. In a continuing attempt to review the progress of NBS globally, and to move towards a more harmonized and equitable screening system, we have updated our 2015 report with information available at the beginning of 2024. Reports on sub-Saharan Africa and the Caribbean, missing in 2015, have been included. Tables popular in the previous report have been updated with an eye towards harmonized comparisons. To emphasize areas needing attention globally, we have used regional tables containing similar listings of conditions screened, numbers of screening laboratories, and time at which specimen collection is recommended. Discussions are limited to bloodspot screening.

Standards for the care of people with cystic fibrosis (CF); Planning for a longer life

This is the final of four papers updating standards for the care of people with CF. That this paper "Planning a longer life" was considered necessary, highlights how much CF care has progressed over the past decade. Several factors underpin this progress, notably increased numbers of people with CF with access to CFTR modulator therapy. As the landscape for CF changes, so do the hopes and aspirations of people with CF and their families. This paper reflects the need to consider people with CF not as a "problem" to be solved, but as a success, a potential and a voice to be heard. People with CF and the wider CF community have driven this approach, reflecting many of the topics in this paper. This exercise involved wide stakeholder engagement. People with CF are keen to contribute to research priorities and be involved in all stages of research. People with CF want healthcare professionals to respect them as individuals and consider the impact of our actions on the world around us. Navigating life presents challenges to all, but for people with CF these challenges are heightened and complex. In this paper we highlight the concerns and life moments that impact people with CF, and events that the CF team should aim to support, including the challenges around having a family. People with CF and their care teams must embrace the updated standards outlined in these four papers to enjoy the full potential for a healthier life.

Outcome data from 15 years of cystic fibrosis newborn screening in a large UK region

BACKGROUND

The West Midlands Newborn Bloodspot Screening Laboratory is one of 16 in the UK and serves two tertiary paediatric cystic fibrosis (CF) centres (Staffordshire Children's Hospital at Royal Stoke and Birmingham Children's Hospital). CF newborn bloodspot screening (NBS) in this region started in November 2006 prior to the UK national roll-out in 2007. It uses an immunoreactive trypsinogen (IRT)/DNA/IRT protocol. We report the outcomes from 15 years of CF screening.

METHODS

The West Midlands CF NBS outcomes from 1 November 2006 to 31 October 2021 were reviewed. Clinical data were also obtained for babies referred to the CF centres as 'CF suspected'.

RESULTS

1 075 161 babies were screened, with 402 referred as 'CF suspected' and 205 identified as CF carriers. Of the 'CF suspected' babies, 268 were diagnosed with CF, 33 with CF screen positive, inconclusive diagnosis (CFSPID) and 17 as a CF carrier. Any CF-related diagnosis was excluded in 67. Outcome data were not available for 17, of whom 14 had died. Eighteen children with a negative CF NBS have subsequently been diagnosed with CF, 10 had meconium ileus and 8 were true 'affected not detected', presenting with respiratory symptoms or failure to thrive. This gives the West Midlands a CF birth prevalence of 1 in 4012 live births and the NBS protocol a sensitivity of 97.1% and a positive predictive value of 66.7%.

CONCLUSIONS

This large regional data set has excellent case ascertainment and demonstrates successful performance of the CF NBS protocol, with low numbers identified as CFSPID or CF carriers.

Impact of intrinsic and extrinsic risk factors on early-onset lung disease in cystic fibrosis

BACKGROUND

Although respiratory pathology is known to develop in young children with cystic fibrosis (CF), the determinants of early-onset lung disease have not been elucidated.

OBJECTIVE

We aimed to determine the impact of potential intrinsic and extrinsic risk factors during the first 3 years of life, testing the hypothesis that both contribute significantly to early-onset CF lung disease.

DESIGN

We studied 104 infants born during 2012-2017, diagnosed through newborn screening by age 3 months, and evaluated comprehensively to 36 months of age. Lung disease manifestations were quantified with a new scoring system known as CFELD for Cystic Fibrosis Early-onset Lung Disease. The variants in the cystic fibrosis transmembrane conductance regulator (CFTR) gene were determined and categorized. Whole genome sequencing was performed on each subject and the data transformed to polygenic risk scores (PRS) that aggregate variants associated with lung function. Extrinsic factors included socioeconomic status (SES) indicators and environmental experiences such as exposures to smoking, pets, and daycare.

RESULTS

We found by univariate analysis that CFTR genotype and genetic modifiers aggregated by the PRS method were significantly associated with early-onset CF lung disease. Ordinal logistic regression analysis demonstrated that high and stable SES (maternal education ≥community college, stable 2-parent home, and not receiving Medicaid) and better growth (weight-for-age and height-for-age z-scores) reduced risks, while exposure to smoking and daycare ≥20 h/week increased the risk of CFELD severity.

CONCLUSIONS

Extrinsic, modifiable determinants are influential early and potentially as important as the intrinsic risk factors in the onset of CF lung disease.

Cystic Fibrosis screen positive, inconclusive diagnosis (CFSPID) to Cystic Fibrosis: Detecting disease with serial assessments

We present the case of a child given a CFSPID designation in early life who was later reclassified as having CF based on a combination of recurrent respiratory symptoms and CFTR functional testing, despite normal sweat chloride levels. Here we demonstrate the importance of monitoring these children, each time reviewing the diagnosis based on updated understanding of individual CFTR mutation phenotypes or clinical findings inconsistent with the designation. This case identifies situations in which the CFSPID designation should be challenged, and gives an approach for this when CF is suspected.

Child poverty and health inequalities in the UK: a guide for paediatricians

One in three children in the UK lives in relative poverty. There are clear and consistent links between child poverty and paediatric morbidity and mortality. In this review, we discuss drivers for family poverty in the UK, and how this leads to poor child health outcomes. We present a framework for healthcare professionals and institutions to consider interventions and strategies relating to socioeconomic health inequalities. We will focus on approaches to mitigate the effects of child poverty on children using our services at a local level and outline the importance of healthcare workers advocating for structural and high-level policy change to address the deep-rooted societal problems that cause child poverty.

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.

Does newborn screening improve early lung function in cystic fibrosis?

Despite evidence showing an improvement in nutritional outcomes following diagnosis by newborn screening (NBS) for cystic fibrosis (CF), the impact on pulmonary outcomes has been less clear. In this review the approaches to measurement of early lung function and knowledge gained from NBS CF cohorts will be described. Studies which have compared outcomes in those diagnosed by NBS to those diagnosed following symptomatic presentation will be presented. Compiling the evidence base used to evaluate the impact of NBS on pulmonary outcomes has been complicated by improvements in clinical management, infection control practices, as well as public health interventions (such as tobacco smoking bans in public places) that have evolved substantially over recent decades. Forced expiratory volumes have been used as the main outcome but it is important not to draw conclusions for 'early lung function' from tests such as spirometry alone, which lack sensitivity in early lung disease. There is, at present, insufficient evidence to draw firm conclusions about the effect of NBS on early lung function. In an era of highly effective treatments targeting the underlying molecular defect responsible for CF, future opportunities for early initiation of treatment may mean that the impact of NBS on early lung function may yet to be realised.

'We're kind of like genetic nomads': Parents' experiences of biographical disruption and uncertainty following in/conclusive results from newborn cystic fibrosis screening

As whole genome sequencing is being considered as a tool to deliver expanded newborn screening (NBS) globally, the range of equivocal results it could produce are gaining increased attention. For cystic fibrosis (CF) screening, the use of next generation sequencing within existing UK NBS programmes would increase the number of uncertain designations returned within results, including that of Cystic Fibrosis Screen Positive Inconclusive Diagnosis (CFSPID). However, the experiences of families already living with this designation have been under-explored. This study uses in-depth interviews to explore the perspectives of sixteen parents who received positive results from CF NBS, with varying degrees of prognostic un/certainty; parents with a child diagnosed with CF (n = 6), CF carrier status (n = 3) and those with the CFSPID designation (n = 7). The biographically disruptive nature of positive NBS results-regardless of immediate relevance to the child-dominated early experiences of positive results across all groups. For those with CF, biographical reparation involved becoming 'a CF family', underscoring biological kinship bonds and reinforcing familial identity. For those with uncertain results, biographical re-calibration was more complex. Diagnostic and prognostic uncertainty posed a barrier to entry for both the 'CF world' and the 'healthy kid' world, leading parents to attempt to minimise its role, either through rejection, or re-interpretation of their child's result. Other parents, however, experienced biographical reparation more dynamically. The concept of 'genetic nomadism' captures accounts of oscillation between the two worlds; movements that were responsive to evolving health experiences, as well as social, environmental and temporal factors. Through the concept of genetic nomadism, this paper delineates both the productive, as well as divisive, nature of uncertainty for biographical reparation in the aftermath of NBS, as well as the strategies parents use to harness it, in order to successfully navigate the world with a child with an ambiguous genetic future.

Cystic fibrosis newborn screening: Five-year experience from a tertiary care center

BACKGROUND

Newborn screening (NBS) for cystic fibrosis (CF) was implemented in our country on January 1, 2015, based on immunoreactive trypsinogen tests (IRT/IRT). Here, we aimed to evaluate the diagnoses of patients and follow-up process within the first 5 years of NBS from a tertiary care center.

METHODS

This retrospective cohort study was conducted on patients who were admitted to our pediatric pulmonology department for sweat test (ST) via NBS. Patients with CF with negative NBS results and those with CF with positive NBS and joined our follow-up were also investigated. Clinical outcome measures were compared between patients with CF with positive and negative NBS.

RESULTS

Six hundred sixty infants who were referred for ST via NBS were included. Across the entire study population (n = 683), 11.4% of patients had CF (14.1% of had negative NBS in this CF group). The sensitivity of NBS was found as 84.9% and the positive predictive value (PPV) was 9.4%. The median age at diagnosis was older (p < 0.001), reluctance for feeding and Pseudobartter syndrome (PBS) were significantly higher at presentation in the negative NBS group. There was no statistically significant difference between the groups regarding weight-for-age (p = 0.899) and height-for-age (p = 0.491) in the first 2 years' follow-ups.

CONCLUSIONS

Our findings showed the low sensitivity and PPV of NBS; therefore, further studies based on all patients in our country are necessary for new cut-off values. PBS and reluctance for feeding should be alarm symptoms for CF even if the infants had negative NBS. Additionally, later diagnosis of patients who had negative NBS did not affect the nutritional outcomes; we need large-scale prospective studies to optimize nutritional benefits for all infants diagnosed via NBS.

Health disparity in CF: Perspectives from a lived experience

In this commentary, we discuss health disparities, reflecting on our experience in delayed diagnosis of cystic fibrosis based on race and bias in healthcare practitioners.

Outcomes of infants born during the first 9 years of CF newborn screening in the United States: A retrospective Cystic Fibrosis Foundation Patient Registry cohort study

INTRODUCTION

Newborn screening (NBS) for cystic fibrosis (CF) was implemented in all US states and DC by 2010. This hypothesis-generating study was designed to form the basis of additional analyses and to plan quality improvement initiatives. The aims were to describe the outcomes of infants with CF born during the first 9 years of universal NBS.

METHODS

We included participants in the CF Foundation Patient Registry born 2010-2018 with age of recorded CF diagnosis 0-365 days old. We compared the age of center-reported diagnosis, age at first CF event (defined as earliest sweat test, clinic visit, or hospitalization), demographics, and outcomes between three cohorts born between 2010-2012, 2013-2015, and 2016-2018.

RESULTS

In 6354 infants, the median age at first CF event decreased from the first to the third cohort. Weight-for-age (WFA) was < 10th percentile in about 40% of infants at the first CF Center visit. Median WFA z-score at 1-2 years was more than 0 but height-for-age (HFA) z-score was less than 0 through age 5-6 years. The second cohort had a higher HFA z-score than the first cohort at age 5-6 years. Pseudomonas aeruginosa infection was less common in later cohorts. About 1/3 of infants were hospitalized in the first year of life with no changes over time.

CONCLUSION

Over 9 years of CF NBS, median age at first CF event decreased. CF NBS had positive health impacts, but early life nutritional deficits and a high rate of infant hospitalizations persist.

Geographical barriers to timely diagnosis of cystic fibrosis and anxiety level of parents during newborn screening in Turkey

BACKGROUND

Despite the availability of cystic fibrosis (CF) screening countrywide, diagnostic delay is still a crucial issue. The objectives of this study were to explore the stages of the NBS process, determine the risk factors associated with diagnostic delay and evaluate parent anxiety and experience throughout the process.

METHODS

This is a multicenter cross-sectional study. A questionnaire was completed by parents of newborns diagnosed with CF via NBS in 17 centers. Socio-demographic characteristics, parent knowledge and experiences related to NBS, sweat test availability in the region of residence, and time to the definitive CF diagnosis were assessed through this questionnaire. Parents' anxiety levels were evaluated through the State-Trait Anxiety Inventory scales 1 and 2. Delayed diagnosis (DD) was defined as a definite CF diagnosis beyond the 8th week of life. Predictors of delayed CF diagnosis were evaluated by univariate and multivariate analysis.

RESULTS

A total of 220 CF patients diagnosed via NBS were enrolled; 82 (37.3%) babies had DD. Multivariable analysis indicated that residence in the Southeast Anatolia region of Turkey (OR = 10.79, 95% CI = 2.37-49.2) was associated with a higher incidence of DD compared with other regions in Turkey. Of the total, 216 (98.1%) of the caregivers regarded the NBS program as useful and 180 (82%) reported high anxiety levels.

CONCLUSION

The organization of newborn screening should take into account regional and socio-cultural characteristics to improve the early diagnosis of CF and also reduce the anxiety level of parents.

Year in Review 2020: Multisystemic impact of cystic fibrosis

Clinical care in cystic fibrosis (CF) has continued to advance over the last several years, particularly with the widespread eligibility and use of highly effective modulator therapy. Improved outcomes and longevity of persons with CF (PwCF) have increased recognition of the multisystem impact of the disease on the daily lives of PwCF. This review will cover a broad array of topics, from diagnosis to multisystem effects related to mental health, endocrine, palliative care, reproductive health, otolaryngology, and cardiac issues. Additionally, worldwide care delivery will be reviewed, demonstrating variation in outcomes based on resources and populations served. This review is part of the CF Year in Review 2020 series, focusing on the multi-system effects of CF. This review focuses on articles from Pediatric Pulmonology but also includes articles published in 2020 from other journals that are of particular interest to clinicians.

Two Years of Newborn Screening for Cystic Fibrosis in North Macedonia: First Experience

There is a widely accepted consensus on the benefits of newborn screening (NBS) for cystic fibrosis (CF) in terms of reduced disease severity, improved quality of life, lower treatment burden, and reduced costs. More and more countries in the world are introducing NBS for CF as a national preventive health program. Newborn screening for CF was introduced in the Republic of North Macedonia (RNM) in April, 2019, after a pilot study of 6 months in 2018. A two-step immunoreactive trysinogen (IRT-IRT) algorithm is performed, and then a sweat test for confirmation/exclusion of the CF diagnosis when the IRT values were both over the cutoff (70.0 and 45.0 ng/mL, respectively). In cases with confirmed diagnosis of CF (a sweat chloride concentration >60.0 mmol/L) or with intermediate sweat test results (a sweat chloride concentration of between 30.0 and 59.0 mmol/L), CF transmembrane conductance regulator (CFTR) mutation analysis is performed. By the end of 2020, over a period of 27 months, including the pilot study period, a total number of 43,139 newborns were screened for CF. Seventeen (0.039%) newborns were diagnosed with CF. In all newly discovered CF cases by screening, the diagnosis was confirmed by determination of the CFTR mutations. The most common CFTR mutation, F508del, was found with an overall incidence of 70.6%. Other more frequent mutations were G542X (11.8%) and N1303K (5.9%). Four mutations were found in one CFTR allele each: G1349D, G126D, 457TAT>G and CFTRdupexon22, with the last one being newly discovered with unknown consequences. An incredibly large difference was found in the incidence of the disease between the Macedonian and Albanian neonatal population, with almost four time higher prevalence among Albanians (1:4530 vs. 1:1284).

Actualities in neonatal endocrine and metabolic screening

Neonatal metabolic screening has proven to be an important tool for the early detection of innate metabolic errors. Despite the fact that simple and effective methods of testing for metabolic diseases have been identified since the middle of the twentieth century, no consensus has been reached so far on the content of neonatal metabolic screening panels. There are large differences between countries in the number of metabolic diseases identified through national metabolic screening programs, ranging from zero to several tens, the most common testing being for phenylketonuria and congenital hypothyroidism (including in Romania). Given the fact that rare but treatable diseases have been identified in recent decades, reducing the financial burden on the health system, it would be useful to include them in the national neonatal metabolic screening program.

Newborn screening alone insufficient to improve pulmonary outcomes for cystic fibrosis

BACKGROUND

The Wisconsin Cystic Fibrosis Neonatal Screening Project was a randomized clinical trial (RCT) revealing that children receiving an early diagnosis of CF via newborn screening (NBS) had improved nutritional outcomes but similar lung disease severity compared to those who presented clinically. Because the evaluations of these subjects by protocol ended in 2012, our objective was to assess long-term pulmonary and mortality outcomes.

METHODS

Retrospective analysis of the RCT cohort utilized longitudinal outcome measures obtained from the Cystic Fibrosis Foundation Patient Registry (CFFPR). Data included screening assignment, clinical characteristics, percent predicted forced expiratory volume in 1 s (ppFEV1) and mortality. A random intercept model was used to compare the ppFEV1 decline of subjects between the two groups up to age 26 years. Mortality was analyzed using the Kaplan-Meier method.

RESULTS

Of the 145 subjects who consented to the original study, 104 subjects met inclusion criteria and had adequate data in the CFFPR. Of 57 subjects in the screened group and 47 in the control group, the rates of ppFEV1 decline were 1.76%/year (95% CI 1.62 to 1.91%) and 1.43%/year (95% CI 1.26 to 1.60%), respectively (p<0.0002). Pseudomonas aeruginosa acquired before 2 years was partially responsible. There was no difference in mortality between the two groups.

CONCLUSIONS

NBS alone does not improve pulmonary outcomes in CF, particularly when other risk factors supervene. In an era prior to strict infection control and current therapies, NBS for CF may be associated with worse pulmonary outcomes.

The Role of Extended CFTR Gene Sequencing in Newborn Screening for Cystic Fibrosis

There has been considerable progress in the implementation of newborn screening (NBS) programs for cystic fibrosis (CF), with DNA analysis being part of an increasing number of strategies. Thanks to advances in genomic sequencing technologies, CFTR-extended genetic analysis (EGA) by sequencing its coding regions has become affordable and has already been included as part of a limited number of core NBS programs, to the benefit of admixed populations. Based on results analysis of existing programs, the values and challenges of EGA are reviewed in the perspective of its implementation on a larger scale. Sensitivity would be increased at best by using EGA as a second tier, but this could be at the expense of positive predictive value, which improves, however, if EGA is applied after testing a variant panel. The increased detection of babies with an inconclusive diagnosis has proved to be a major drawback in programs using EGA. The lack of knowledge on pathogenicity and penetrance associated with numerous variants hinders the introduction of EGA as a second tier, but EGA with filtering for all known CF variants with full penetrance could be a solution. The issue of incomplete knowledge is a real challenge in terms of the implemention of NBS extended to many genetic diseases.