The CFTR variant profile of Hispanic patients with cystic fibrosis: Impact on access to effective screening, diagnosis, and personalized medicine.

Hispanic patients comprise an appreciable and increasing proportion of patients with cystic fibrosis (CF) in the United States (US). Hispanic patients with CF are known to have increased morbidity and mortality compared to non-Hispanic white patients with CF, and ongoing investigations are underway to identify contributing factors amenable to intervention in order to address the disparate health outcomes. One contributing factor is the different CF transmembrane conductance regulator (CFTR) variant profile observed in Hispanic patients with CF. The most common CFTR variant, p.Phe508del (legacy name F508del), is proportionally underrepresented in Hispanic patients with CF. This difference has implications for prenatal screening, newborn screening (NBS), and CFTR variant-specific therapeutic options. In particular, the recent approval of a highly effective CFTR modulator for patients carrying at least one copy of F508del, elexacaftor/tezacaftor/ivacaftor triple combination therapy, underscores the potential for unequal access to personalized treatment for Hispanic patients with CF. We report the CFTR variant profiles of Hispanic patients with CF and non-CF Hispanic infants with a false-positive New York State CF NBS at a single center in New York City over a 5-year study period, as an opportunity to address the racial and ethnic disparities that currently exist in CF screening, diagnosis, and treatment. In addition to the previously documented disparate prevalence of the CFTR variant F508del in Hispanic patients, we observed two CFTR variants, p.His609Arg (legacy name H609R) and p.Thr1036Asn (legacy name T1036N), frequently identified in our Hispanic patients of Ecuadorian and Mexican ancestry, respectively, that are not well-described in the US population. The presence of population-specific and individually rare CFTR variants in Hispanic patients with CF further accentuates the disparity in health outcomes, as these CFTR variants are often absent from prenatal and NBS CFTR variant panels, potentially delaying diagnosis, and without an approved CFTR variant-specific therapy.

Clinical Sensitivity of Cystic Fibrosis Mutation Panels in a Diverse Population.

Infants are screened for cystic fibrosis (CF) in New York State (NYS) using an IRT-DNA algorithm. The purpose of this study was to validate and assess clinical validity of the US FDA-cleared Illumina MiSeqDx CF 139-Variant Assay (139-VA) in the diverse NYS CF population. The study included 439 infants with CF identified via newborn screening (NBS) from 2002 to 2012. All had been screened using the Abbott Molecular CF Genotyping Assay or the Hologic InPlex CF Molecular Test. All with CF and zero or one mutation were tested using the 139-VA. DNA extracted from dried blood spots was reliably and accurately genotyped using the 139-VA. Sixty-three additional mutations were identified. Clinical sensitivity of three panels ranged from 76.2% (23 mutations recommended for screening by ACMG/ACOG) to 79.7% (current NYS 39-mutation InPlex panel), up to 86.0% for the 139-VA. For all, sensitivity was highest in Whites and lowest in the Black population. Although the sample size was small, there was a nearly 20% increase in sensitivity for the Black CF population using the 139-VA (68.2%) over the ACMG/ACOG and InPlex panels (both 50.0%). Overall, the 139-VA is more sensitive than other commercially available panels, and could be considered for NBS, clinical, or research laboratories conducting CF screening.

Validation of the Integrated Palliative Care Outcome Scale (IPOS) in adults with cystic fibrosis.

BACKGROUND: A primary palliative care model for cystic fibrosis (CF) recommends using the Integrated Palliative Care Outcome Scale (IPOS) for screening. Validation of the IPOS is needed. METHODS: This secondary analysis utilized baseline data from a multisite trial of the palliative care model, Improving Life with CF. Adults with CF completed the IPOS, the Memorial Symptom Assessment Scale-CF (MSAS-CF), the CF Questionnaire-Revised (CFQ-R), the Patient Health Questionnaire (PHQ-8), the Generalized Anxiety Disorder (GAD-7), and the Perceived Stress Scale (PSS). IPOS structure was assessed using Cronbach α coefficients and a factor analysis. Construct validity was evaluated through bivariate relationships between IPOS scores and other questionnaire scores, and linear regressions assessing the extent to which the IPOS explains variance in quality-of-life domains. RESULTS: The sample comprised 256 adults with complete IPOS data. α coefficients were .86 for the IPOS total score, .81 for the Physical Symptoms subscale, .79 for the Emotional Symptoms subscale, and .63 for the Communication/Practical Issues subscale. A two-component factor structure best aligned with the current subscales. IPOS scores were significantly associated with other measures; associations with MSAS-CF and CFQ-R subscales differentiated the IPOS Physical and Emotional subscales. The IPOS total score provided unique information about the variance in the CFQ-R Physical Functioning and Respiratory Symptoms domain scores. CONCLUSIONS: In adults with CF, the IPOS has acceptable internal consistency and there is evidence of construct validity. These findings support adoption of the IPOS in the primary palliative care model for CF.

Center-level self-study identifies opportunities to advance equity in cystic fibrosis clinical trial participation.

Clinical trials are a necessary tool for evaluating the effectiveness of newly developed treatments and interventions for cystic fibrosis (CF). Prior work demonstrated a proportional underrepresentation of people with CF (pwCF) identifying as part of a minoritized racial or ethnic group in clinical trials. In order to establish a baseline for improvement efforts, we undertook a center-level self-study to evaluate if the racial and ethnic backgrounds of pwCF participating in clinical trials at our CF Center in New York City reflect our overall patient diversity (N = 200; 55 pwCF identifying as part of a minoritized racial or ethnic group and 145 pwCF identifying as non-Hispanic White). A smaller proportion of pwCF identifying as part of a minoritized racial or ethnic group participated in a clinical trial as compared to pwCF identifying as non-Hispanic White (21.8% vs. 35.9%, P = 0.06). A similar trend was present for pharmaceutical clinical trials (9.1% vs. 16.6%, P = 0.3). When limiting the study population to the pwCF most likely to be eligible for a CF pharmaceutical clinical trial, a larger proportion of pwCF identifying as part of a minoritized racial or ethnic group participated in a pharmaceutical clinical trial as compared to pwCF identifying as non-Hispanic White (36.4% vs. 19.6%, P = 0.2). No pwCF identifying as part of a minoritized racial or ethnic group participated in an offsite clinical trial. Efforts to improve the racial and ethnic diversity of pwCF in clinical trials, both onsite and offsite, will require a shift in how recruitment opportunities are identified and communicated to pwCF.