Quantity not sufficient rates and delays in sweat testing in US infants with cystic fibrosis

Background Diagnostic sweat testing is required for infants with positive newborn-screening (NBS) tests for cystic fibrosis (CF). Infants have “quantity not sufficient” (QNS) sweat volumes more often than older children. A comprehensive study of QNS sweat volumes in infants has not previously been reported. Methods We surveyed US CF Centers to obtain QNS rates in all infants who had sweat testing at under 14 days and under 3 months of age. We then calculated QNS rates reported to the Cystic Fibrosis Foundation Patient Registry (CFFPR) 2010-2018 in 10-day increments from 1 to 60 days of life. We compared QNS sweat test rates in preterm (<37-weeks gestational age) vs term infants. We assessed age at sweat test and proportion of infants who did not have a sweat test reported by 60 days of age. Results Thirty-nine of 144 (27%) of CF Centers reported a mean QNS rate of 10.5% (range, 0-100) in infants 14-days-old or younger. CFFPR data showed the highest QNS rates in the youngest infants and in those born before 37 weeks of gestation. The median age at sweat testing decreased over time, but more than 22% of infants did not have a sweat test reported by 60 days. Conclusion Higher QNS rates are seen in the youngest infants with CF, but more than 80% of infants younger than 2 weeks of age have adequate sweat volumes. Sweat testing should not be delayed in infants with a positive CF NBS test

Diagnosis of Cystic Fibrosis: Consensus Guidelines from the Cystic Fibrosis Foundation

Objective Cystic fibrosis (CF), caused by mutations in the CF transmembrane conductance regulator (CFTR) gene, continues to present diagnostic challenges. Newborn screening and an evolving understanding of CF genetics have prompted a reconsideration of the diagnosis criteria. Study design To improve diagnosis and achieve standardized definitions worldwide, the CF Foundation convened a committee of 32 experts in CF diagnosis from 9 countries to develop clear and actionable consensus guidelines on the diagnosis of CF and to clarify diagnostic criteria and terminology for other disorders associated with CFTR mutations. An a priori threshold of ≥80% affirmative votes was required for acceptance of each recommendation statement. Results After reviewing relevant literature, the committee convened to review evidence and cases. Following the conference, consensus statements were developed by an executive subcommittee. The entire consensus committee voted and approved 27 of 28 statements, 7 of which needed revisions and a second round of voting. Conclusions It is recommended that diagnoses associated with CFTR mutations in all individuals, from newborn to adult, be established by evaluation of CFTR function with a sweat chloride test. The latest mutation classifications annotated in the Clinical and Functional Translation of CFTR project (http://www.cftr2.org/index.php) should be used to aid in diagnosis. Newborns with a high immunoreactive trypsinogen level and inconclusive CFTR functional and genetic testing may be designated CFTR-related metabolic syndrome or CF screen positive, inconclusive diagnosis; these terms are now merged and equivalent, and CFTR-related metabolic syndrome/CF screen positive, inconclusive diagnosis may be used. International Statistical Classification of Diseases and Related Health Problems, 10th Revision codes for use in diagnoses associated with CFTR mutations are included

Diagnosis of Cystic Fibrosis in Screened Populations

Objective Cystic fibrosis (CF) can be difficult to diagnose, even when newborn screening (NBS) tests yield positive results. This challenge is exacerbated by the multitude of NBS protocols, misunderstandings about screening vs diagnostic tests, and the lack of guidelines for presumptive diagnoses. There is also confusion regarding the designation of age at diagnosis. Study design To improve diagnosis and achieve standardization in definitions worldwide, the CF Foundation convened a committee of 32 experts with a mission to develop clear and actionable consensus guidelines on diagnosis of CF with an emphasis on screened populations, especially the newborn population. A comprehensive literature review was performed with emphasis on relevant articles published during the past decade. Results After reviewing the common screening protocols and outcome scenarios, 14 of 27 consensus statements were drafted that apply to screened populations. These were approved by 80% or more of the participants. Conclusions It is recommended that all diagnoses be established by demonstrating dysfunction of the CF transmembrane conductance regulator (CFTR) channel, initially with a sweat chloride test and, when needed, potentially with newer methods assessing membrane transport directly, such as intestinal current measurements. Even in babies with 2 CF-causing mutations detected via NBS, diagnosis must be confirmed by demonstrating CFTR dysfunction. The committee also recommends that the latest classifications identified in the Clinical and Functional Translation of CFTR project [http://www.cftr2.org/index.php] should be used to aid with CF diagnosis. Finally, to avoid delays in treatment, we provide guidelines for presumptive diagnoses and recommend how to determine the age of diagnosis

Updated guidance on the management of children with cystic fibrosis transmembrane conductance regulator-related metabolic syndrome/cystic fibrosis screen positive, inconclusive diagnosis (CRMS/CFSPID)

Over the past two decades there has been considerable progress with the evaluation and management of infants with an inconclusive diagnosis following Newborn Screening (NBS) for cystic Fibrosis (CF). In addition, we have an increasing amount of evidence on which to base guidance on the management of these infants and, importantly, we have a consistent designation being used across the globe of CRMS/CFSPID. There is still work to be undertaken and research questions to answer, but these infants now receive more consistent and appropriate care pathways than previously. It is clear that the majority of these infants remain healthy, do not convert to a diagnosis of CF in childhood, and advice on management should reflect this. However, it is also clear that some will convert to a CF diagnosis and monitoring of these infants should facilitate their early recognition. Those infants that do not convert to a CF diagnosis have some potential of developing a CFTR-RD later in life. At present, it is not possible to quantify this risk, but families need to be provided with clear information of what to look out for. This paper contains a number of changes from previous guidance in light of developing evidence, but the major change is the recommendation of a detailed assessment of the child with CRMS/CFSPID in the sixth year of age, including respiratory function assessment and imaging. With these data, the CF team can discuss future care arrangements with the family and come to a shared decision on the best way forward, which may include discharge to primary care with appropriate information. Information is key for these families, and we recommend consideration of a further appointment when the individual is a young adult to directly communicate the implications of the CRMS/CFSPID designation

Minorities Are Underrepresented in Clinical Trials of Pharmaceutical Agents for Cystic Fibrosis.

RationaleMembers of racial or ethnic minorities make up an appreciable proportion of patients with cystic fibrosis (CF) and have worse outcomes than non-Latino white individuals. Between 1,999 and 2014, the CF Foundation Patient Registry reported an increase in minorities from 5 to 8.2% for Latinos, from 3 to 4.6% for black individuals and from 1.4 to 3.1% for "Other."ObjectivesTo evaluate the representation of racial and ethnic minorities in pharmacology clinical trials for CF.MethodsWe analyzed pharmacology clinical trials in CF published between 1999 and 2015 by searching PubMed and published study reference lists for qualifying study reports. We examined whether the race and ethnicity of study subjects were reported and, if so, what percentage of subjects represented major minority groups.Measurements and main resultsAmong 147 pharmacology clinical trials, only 19.7% reported the race or ethnicity of study subjects. Latinos were verified as included in 7.5% of clinical trials, black individuals in 6.8%, and Asians in 2.0%. Inclusion of subjects described as "Other race" was reported in 7.5% of trials. In 29 clinical trials that reported race and ethnicity, the percentage of minorities included as subjects was 2.0% for Latinos, 1.0% for black individuals, and 0.1% for Asians.ConclusionsAlthough CF disproportionately affects non-Latino white individuals, members of other racial or ethnic groups are proportionally underrepresented in CF pharmacology clinical trials. Inadequate inclusion of minorities and failure to report the racial or ethnic background of study subjects limits information about factors influencing drug response and may contribute to health disparities for minorities with CF

Minorities are Underrepresented in Clinical Trials of Pharmaceutical Agents for Cystic Fibrosis

Rationale: Members of racial or ethnic minorities make up an appreciable proportion of patients with cystic fibrosis (CF) and have worse outcomes than non-Latino white individuals. Between 1,999 and 2014, the CF Foundation Patient Registry reported an increase in minorities from 5 to 8.2% for Latinos, from 3 to 4.6% for black individuals and from 1.4 to 3.1% for “Other.” Objectives: To evaluate the representation of racial and ethnic minorities in pharmacology clinical trials for CF. Methods: We analyzed pharmacology clinical trials in CF published between 1999 and 2015 by searching PubMed and published study reference lists for qualifying study reports. We examined whether the race and ethnicity of study subjects were reported and, if so, what percentage of subjects represented major minority groups. Measurements and Main Results: Among 147 pharmacology clinical trials, only 19.7% reported the race or ethnicity of study subjects. Latinos were verified as included in 7.5% of clinical trials, black individuals in 6.8%, and Asians in 2.0%. Inclusion of subjects described as “Other race” was reported in 7.5% of trials. In 29 clinical trials that reported race and ethnicity, the percentage of minorities included as subjects was 2.0% for Latinos, 1.0% for black individuals, and 0.1% for Asians. Conclusions: Although CF disproportionately affects non-Latino white individuals, members of other racial or ethnic groups are proportionally underrepresented in CF pharmacology clinical trials. Inadequate inclusion of minorities and failure to report the racial or ethnic background of study subjects limits information about factors influencing drug response and may contribute to health disparities for minorities with CF

Transcriptome Profiling and Molecular Therapeutic Advances in Cystic Fibrosis: Recent Insights

In cystic fibrosis (CF), mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene disrupt the capacity of the encoded protein to function as a channel to transport chloride ions and water across cell membranes. The consequences are deleterious, system-wide, and immensely variable, even among patients with the same CFTR genotype. This underscores the need to characterize the mechanisms contributing to CF pathophysiology. Gene replacement and gene editing therapies have been pursued intensively and are expected to provide a one-time treatment for CF. However, gene replacement therapy is limited by the lack of efficient vectors to deliver functional copies of CFTR to cells without immunological complications, while gene editing technologies such as CRISPR/Cas9 are still in their infancy, mainly useful in somatic cells and limited by off-target insertions. Small molecule treatments targeted at potentiating or correcting CFTR have shown clinical benefits, but they are limited to a few CFTR mutations and insufficient to overcome challenges related to clinical heterogeneity. Transcriptome profiling approaches have emerged as robust tools capable of characterizing phenotypic variability and revealing novel molecular targets with therapeutic potential for CF. We summarize current insights gained through transcriptome profiling approaches in CF studies and recent advances in molecular therapeutics