Abdominal Surgical Procedures in Adult Patients With Cystic Fibrosis: What Are the Risks?

BACKGROUND: With advances in medical care, patients with cystic fibrosis are more commonly living into adulthood, yet there are limited data describing the need for GI surgery and its outcomes in adult cystic fibrosis patients. OBJECTIVE: We aim to use a national administrative database to evaluate trends in abdominal GI surgery and associated postoperative outcomes among adult cystic fibrosis patients. DESIGN: This was a national retrospective cohort study. SETTING: A national all-payor administrative database from 2000 to 2014 was used. PATIENTS: Patients included adults (age ≥18 years) with cystic fibrosis undergoing abdominal GI surgery. MAIN OUTCOME MEASURES: The primary outcome was trend over time in number of surgical admissions. Secondary outcomes included morbidity and mortality by procedure type. RESULTS: We identified 3075 admissions for abdominal surgery, of which 28% were elective. Major GI surgical procedures increased over the study period ( p < 0.01), whereas appendectomy and cholecystectomy did not demonstrate a clear trend ( p = 0.90). The most common procedure performed was cholecystectomy ( n = 1280; 42%). The most common major surgery was segmental colectomy ( n = 535; 18%). Obstruction was the most common surgical indication ( n = 780; 26%). For major surgery, in-hospital mortality was 6%, morbidity was 37%, and mean length of stay was 15.9 days (SE 1.2). LIMITATIONS: The study is limited by a lack of granular physiological and clinical data within the administrative data source. CONCLUSIONS: Major surgical admissions for adult patients with cystic fibrosis are increasing, with the majority being nonelective. Major surgery is associated with significant morbidity, mortality, and prolonged length of hospital stay. These findings may inform perioperative risk for adult patients with cystic fibrosis in need of GI surgery. See Video Abstract at http://links.lww.com/DCR/B850 . PROCEDIMIENTOS QUIRRGICOS ABDOMINALES EN PACIENTES ADULTOS CON FIBROSIS QUSTICA CULES SON LOS RIESGOS: ANTECEDENTES:Con los avances en la medicina, los pacientes con fibrosis quística viven más comúnmente hasta la edad adulta, pero hay datos escasos que describan la necesidad de cirugía gastrointestinal y sus resultados en pacientes adultos con fibrosis quística.OBJETIVO:Nuestro objetivo es utilizar una base de datos administrativa nacional para evaluar las tendencias en la cirugía gastrointestinal abdominal y los resultados posoperatorios asociados entre los pacientes adultos con fibrosis quística.DISEÑO:Estudio de cohorte retrospectivo nacional.AJUSTE:Base de datos administrativa nacional de todas las instituciones pagadoras desde 2000 a 2014.PACIENTES:Todos los pacientes adultos (edad> 18) con fibrosis quística sometidos a cirugía gastrointestinal abdominal.PRINCIPALES MEDIDAS DE RESULTADO:El resultado primario fue la tendencia a lo largo del tiempo en el número de ingresos quirúrgicos. Los resultados secundarios incluyeron morbilidad y mortalidad por tipo de procedimiento.RESULTADOS:Identificamos 3.075 ingresos por cirugía abdominal de los cuales el 28% fueron electivos. Los procedimientos quirúrgicos gastrointestinales mayores aumentaron durante el período de estudio (p <0,01) mientras que la apendicectomía y la colecistectomía no demostraron una tendencia clara (p = 0,90). El procedimiento realizado con mayor frecuencia fue la colecistectomía (n = 1.280; 42%). La cirugía mayor más común fue la colectomía segmentaria (n = 535; 18%). La obstrucción fue la indicación quirúrgica más común (n = 780; 26%). Para la cirugía mayor, la mortalidad hospitalaria fue del 6%, la morbilidad del 37% y la estadía media de 15,9 días (EE 1,2).LIMITACIONES:El estudio está limitado por la falta de datos clínicos y fisiológicos granulares dentro de la fuente de datos administrativos.CONCLUSIONES:Los ingresos quirúrgicos mayores de pacientes adultos con fibrosis quística están aumentando y la mayoría no son electivos. La cirugía mayor se asocia con una morbilidad y mortalidad significativas y una estancia hospitalaria prolongada. Estos hallazgos pueden informar el riesgo perioperatorio para pacientes adultos con fibrosis quística que necesitan cirugía gastrointestinal. Consulte Video Resumen en http://links.lww.com/DCR/B850 . (Traducción-Dr. Felipe Bellolio ).

Time-to-positivity of Mycobacterium avium complex in broth culture associates with culture conversion.

BACKGROUND: Mycobacterial time to positivity (TTP) in liquid culture media has predictive value for longer term outcomes in pulmonary tuberculosis, but has not been thoroughly studied in nontuberculous mycobacterial pulmonary disease. This study sought to evaluate for association between TTP and sputum culture conversion to negative in pulmonary disease caused by Mycobacterium avium complex (MAC). METHODS: Data from the CONVERT trial (NCT02344004) that evaluated efficacy of guideline-based-therapy with or without amikacin liposome inhalation suspension in adults with refractory MAC-PD (Mycobacterium avium complex pulmonary disease) were analyzed. We evaluated TTP measures for sputum obtained prior to study treatment initiation and at monthly visits, assessing reproducibility of measures as well as association of TTP with culture conversion on treatment. RESULTS: Data from 71 participants with at least one screening visit TTP value were analyzed. For participants who provided more than one sputum sample at a given visit, there was moderate between-sample reliability, with median intraclass correlation coefficient 0.62 (IQR 0.50, 0.70). Median TTP at screening was longer in those participants who subsequently achieved vs. did not achieve culture conversion (10.5 [IQR 9.4] days vs. 4.2 [IQR 2.8] days, p = 0.0002). Individuals with culture conversion by study treatment month 6 were more likely to have a screening TTP > 5 days compared to those who did not achieve culture conversion (OR 15.4, 95% CI 1.9, 716.7, p = 0.0037) and had increasing TTPs over time. CONCLUSIONS: TTP prior to and on treatment is associated with microbiological treatment response in patients with MAC-PD.

A Randomized Clinical Trial of Antimicrobial Duration for Cystic Fibrosis Pulmonary Exacerbation Treatment.

Rationale: People with cystic fibrosis (CF) experience acute worsening of respiratory symptoms and lung function known as pulmonary exacerbations. Treatment with intravenous antimicrobials is common; however, there is scant evidence to support a standard treatment duration. Objectives: To test differing durations of intravenous antimicrobials for CF exacerbations. Methods: STOP2 (Standardized Treatment of Pulmonary Exacerbations 2) was a multicenter, randomized, controlled clinical trial in exacerbations among adults with CF. After 7-10 days of treatment, participants exhibiting predefined lung function and symptom improvements were randomized to 10 or 14 days' total antimicrobial duration; all others were randomized to 14 or 21 days' duration. Measurements and Main Results: The primary outcome was percent predicted FEV1 (ppFEV1) change from treatment initiation to 2 weeks after cessation. Among early responders, noninferiority of 10 days to 14 days was tested; superiority of 21 days compared with 14 days was compared for the others. Symptoms, weight, and adverse events were secondary. Among 982 randomized people, 277 met improvement criteria and were randomized to 10 or 14 days of treatment; the remaining 705 received 21 or 14 days of treatment. Mean ppFEV1 change was 12.8 and 13.4 for 10 and 14 days, respectively, a ‒0.65 difference (95% CI [‒3.3 to 2.0]), excluding the predefined noninferiority margin. The 21- and 14-day arms experienced 3.3 and 3.4 mean ppFEV1 changes, a difference of ‒0.10 (‒1.3 to 1.1). Secondary endpoints and sensitivity analyses were supportive. Conclusions: Among adults with CF with early treatment improvement during exacerbation, ppFEV1 after 10 days of intravenous antimicrobials is not inferior to 14 days. For those with less improvement after one week, 21 days is not superior to 14 days. Clinical trial registered with www.clinicaltrials.gov (NCT02781610).

Reconciling Antimicrobial Susceptibility Testing and Clinical Response in Antimicrobial Treatment of Chronic Cystic Fibrosis Lung Infections.

Median cystic fibrosis (CF) survival has increased dramatically over time due to several factors, including greater availability and use of antimicrobial therapies. During the progression of CF lung disease, however, the emergence of multidrug antimicrobial resistance can limit treatment effectiveness, threatening patient longevity. Current planktonic-based antimicrobial susceptibility testing lacks the ability to predict clinical response to antimicrobial treatment of chronic CF lung infections. There are numerous reasons for these limitations including bacterial phenotypic and genotypic diversity, polymicrobial interactions, and impaired antibiotic efficacy within the CF lung environment. The parallels to other chronic diseases such as non-CF bronchiectasis are discussed as well as research priorities for moving forward.

Advances in bronchiectasis: endotyping, genetics, microbiome, and disease heterogeneity.

Bronchiectasis is characterised by pathological dilation of the airways. More specifically, the radiographic demonstration of airway enlargement is the common feature of a heterogeneous set of conditions and clinical presentations. No approved therapies exist for the condition other than for bronchiectasis caused by cystic fibrosis. The heterogeneity of bronchiectasis is a major challenge in clinical practice and the main reason for difficulty in achieving endpoints in clinical trials. Recent observations of the past 2 years have improved the understanding of physicians regarding bronchiectasis, and have indicated that it might be more effective to classify patients in a different way. Patients could be categorised according to a heterogeneous group of endotypes (defined by a distinct functional or pathobiological mechanism) or by clinical phenotypes (defined by relevant and common features of the disease). In doing so, more specific therapies needed to effectively treat patients might finally be developed. Here, we describe some of the recent advances in endotyping, genetics, and disease heterogeneity of bronchiectasis including observations related to the microbiome.

Pulmonary Complications of Cystic Fibrosis.

Cystic fibrosis (CF) lung disease is characterized by the development of progressive bronchiectasis and impaired lung function with severe airflow obstruction. CF patients suffer from shortened life expectancy, primarily driven by respiratory failure. The mechanism by which CF lung disease develops is the result of an interplay of multiple intrinsic and extrinsic factors including genotype, abnormalities in mucus composition and movement, chronic inflammation, and chronic airway infection. Although all CF patients are at increased risk for pulmonary complications including hemoptysis, pneumothorax, pulmonary hypertension, and chronic hypoxic and hypercapnic respiratory failure, the risk of developing these complications increases with progression of lung disease. The focus of this article is to summarize the pathophysiology, epidemiology, and management of these key pulmonary complications.

Amikacin Liposome Inhalation Suspension for Treatment-Refractory Lung Disease Caused by Mycobacterium avium Complex (CONVERT). A Prospective, Open-Label, Randomized Study.

Rationale: Improved therapeutic options are needed for patients with treatment-refractory nontuberculous mycobacterial lung disease caused by Mycobacterium avium complex (MAC). Objectives: To evaluate the efficacy and safety of daily amikacin liposome inhalation suspension (ALIS) added to standard guideline-based therapy (GBT) in patients with refractory MAC lung disease. Methods: Adults with amikacin-susceptible MAC lung disease and MAC-positive sputum cultures despite at least 6 months of stable GBT were randomly assigned (2:1) to receive ALIS with GBT (ALIS + GBT) or GBT alone. Once-daily ALIS was supplied in single-use vials delivering 590 mg amikacin to the nebulizer. The primary endpoint was culture conversion, defined as three consecutive monthly MAC-negative sputum cultures by Month 6. Measurements and Main Results: Enrolled patients (ALIS + GBT, n = 224; GBT-alone, n = 112) were a mean 64.7 years old and 69.3% female. Most had underlying bronchiectasis (62.5%), chronic obstructive pulmonary disease (14.3%), or both (11.9%). Culture conversion was achieved by 65 of 224 patients (29.0%) with ALIS + GBT and 10 of 112 (8.9%) with GBT alone (odds ratio, 4.22; 95% confidence interval, 2.08-8.57; P < 0.001). Patients in the ALIS + GBT arm versus GBT alone were more likely to achieve conversion (hazard ratio, 3.90; 95% confidence interval, 2.00-7.60). Respiratory adverse events (primarily dysphonia, cough, and dyspnea) were reported in 87.4% of patients receiving ALIS + GBT and 50.0% receiving GBT alone; serious treatment-emergent adverse events occurred in 20.2% and 17.9% of patients, respectively. Conclusions: Addition of ALIS to GBT for treatment-refractory MAC lung disease achieved significantly greater culture conversion by Month 6 than GBT alone, with comparable rates of serious adverse events. Clinical trial registered with www.clinicaltrials.gov (NCT02344004).

Lumacaftor-Ivacaftor in Patients with Cystic Fibrosis Homozygous for Phe508del CFTR.

BACKGROUND: Cystic fibrosis is a life-limiting disease that is caused by defective or deficient cystic fibrosis transmembrane conductance regulator (CFTR) protein activity. Phe508del is the most common CFTR mutation. METHODS: We conducted two phase 3, randomized, double-blind, placebo-controlled studies that were designed to assess the effects of lumacaftor (VX-809), a CFTR corrector, in combination with ivacaftor (VX-770), a CFTR potentiator, in patients 12 years of age or older who had cystic fibrosis and were homozygous for the Phe508del CFTR mutation. In both studies, patients were randomly assigned to receive either lumacaftor (600 mg once daily or 400 mg every 12 hours) in combination with ivacaftor (250 mg every 12 hours) or matched placebo for 24 weeks. The primary end point was the absolute change from baseline in the percentage of predicted forced expiratory volume in 1 second (FEV1) at week 24. RESULTS: A total of 1108 patients underwent randomization and received study drug. The mean baseline FEV1 was 61% of the predicted value. In both studies, there were significant improvements in the primary end point in both lumacaftor-ivacaftor dose groups; the difference between active treatment and placebo with respect to the mean absolute improvement in the percentage of predicted FEV1 ranged from 2.6 to 4.0 percentage points (P<0.001), which corresponded to a mean relative treatment difference of 4.3 to 6.7% (P<0.001). Pooled analyses showed that the rate of pulmonary exacerbations was 30 to 39% lower in the lumacaftor-ivacaftor groups than in the placebo group; the rate of events leading to hospitalization or the use of intravenous antibiotics was lower in the lumacaftor-ivacaftor groups as well. The incidence of adverse events was generally similar in the lumacaftor-ivacaftor and placebo groups. The rate of discontinuation due to an adverse event was 4.2% among patients who received lumacaftor-ivacaftor versus 1.6% among those who received placebo. CONCLUSIONS: These data show that lumacaftor in combination with ivacaftor provided a benefit for patients with cystic fibrosis homozygous for the Phe508del CFTR mutation. (Funded by Vertex Pharmaceuticals and others; TRAFFIC and TRANSPORT ClinicalTrials.gov numbers, NCT01807923 and NCT01807949.).

"Pathogen Eradication" and "Emerging Pathogens": Difficult Definitions in Cystic Fibrosis.

Infection is a common complication of cystic fibrosis (CF) airway disease. Current treatment approaches include early intervention with the intent to eradicate pathogens in the hope of delaying the development of chronic infection and the chronic use of aerosolized antibiotics to suppress infection. The use of molecules that help restore CFTR (cystic fibrosis transmembrane conductance regulator) function, modulate pulmonary inflammation, or improve pulmonary clearance may also influence the microbial communities in the airways. As the pipeline of these new entities continues to expand, it is important to define when key pathogens are eradicated from the lungs of CF patients and, equally important, when new pathogens might emerge as a result of these novel therapies.

Optimizing outcomes of pulmonary exacerbations in cystic fibrosis.

PURPOSE OF REVIEW: Pulmonary exacerbations are described as worsening of the daily symptoms of cystic fibrosis airways disease, typically with increased cough and sputum production. There are often associated signs such as weight loss and reduced lung function. These events occur frequently and are associated with considerable cost and morbidity. Although approved maintenance therapies are shown to reduce exacerbations, they still occur and are associated with poor outcomes despite treatment. Guidelines to define best practices found a paucity of evidence upon which to base recommendations. RECENT FINDINGS: There are ongoing studies that are trying to build the evidence upon which to improve our practice. Antibiotics remain a core aspect of treatment, but there is high variance in practice patterns including selection of antibiotics and duration of therapy. In addition, there is a discordance between antibiotic susceptibility test results and clinical outcomes, suggesting we need better approaches to guide antibiotic selection. SUMMARY: Treatment durations are highly variable but recent evidence has demonstrated worse outcomes with shorter durations; longer durations may be associated with complications of treatment, suggesting an optimal duration could be identified. New studies aim to define best practices to improve outcomes with treatment of pulmonary exacerbations.

Nontuberculous Mycobacteria in Cystic Fibrosis.

Nontuberculous mycobacteria (NTM) can cause chronic pulmonary infection in susceptible hosts. Individuals with cystic fibrosis (CF), a multisystem disease predominated by progressive structural lung disease, are particularly vulnerable. Only recently have NTM been recognized for their potential to cause lung deterioration in CF patients. The reported prevalence varies widely from 4 to 40%, significantly more common than in the general population, but this varies because of multiple factors including inconsistent screening practices. Mycobacterium abscessus complex and Mycobacterium avium complex are the two most common species recovered. Defining NTM pulmonary disease in a CF patient can present challenges as it can be difficult to distinguish from the other potentially pathogenic organisms in the lung microbiome. In general, treatment regimens do not differ from the non-CF population but the clinician should be aware of potential interactions with other CF therapies. Recent population-level genomics has raised serious concern for indirect person-to-person transmission of several dominating NTM clones worldwide, raising awareness for increase prevention strategies when CF patients potentially congregate, such as clinic visits. Lung transplantation is controversial in those with NTM present in sputum culture but the available evidence suggests that this is not an absolute contraindication.

Randomized Trial of Liposomal Amikacin for Inhalation in Nontuberculous Mycobacterial Lung Disease.

RATIONALE: Lengthy, multidrug, toxic, and low-efficacy regimens limit management of pulmonary nontuberculous mycobacterial disease. OBJECTIVES: In this phase II study, we investigated the efficacy and safety of liposomal amikacin for inhalation (LAI) in treatment-refractory pulmonary nontuberculous mycobacterial (Mycobacterium avium complex [MAC] or Mycobacterium abscessus) disease. METHODS: During the double-blind phase, patients were randomly assigned to LAI (590 mg) or placebo once daily added to their multidrug regimen for 84 days. Both groups could receive open-label LAI for 84 additional days. The primary endpoint was change from baseline to Day 84 on a semiquantitative mycobacterial growth scale. Other endpoints included sputum conversion, 6-minute-walk distance, and adverse events. MEASUREMENTS AND MAIN RESULTS: The modified intention-to-treat population included 89 (LAI = 44; placebo = 45) patients. The average age of the sample was 59 years; 88% were female; 92% were white; and 80 and 59 patients completed study drug dosing during the double-blind and open-label phases, respectively. The primary endpoint was not achieved (P = 0.072); however, a greater proportion of the LAI group demonstrated at least one negative sputum culture (14 [32%] of 44 vs. 4 [9%] of 45; P = 0.006) and improvement in 6-minute-walk test (+20.6 m vs. -25.0 m; P = 0.017) at Day 84. A treatment effect was seen predominantly in patients without cystic fibrosis with MAC and was sustained 1 year after LAI. Most adverse events were respiratory, and in some patients it led to drug discontinuation. CONCLUSIONS: Although the primary endpoint was not reached, LAI added to a multidrug regimen produced improvements in sputum conversion and 6-minute-walk distance versus placebo with limited systemic toxicity in patients with refractory MAC lung disease. Further research in this area is needed. Clinical trial registered with www.clinicaltrials.gov (NCT01315236).

Pediatric and Adult Recommendations Vary for Sibling Testing in Cystic Fibrosis.

Four to 5 % of cystic fibrosis (CF) patients are diagnosed as adults and often have subtler symptoms. Their siblings are at genetic risk to also have a subtler disease state. Diagnostic testing is recommended for siblings of newly diagnosed infants, but recommendations are less clear for later diagnoses. This study explored sibling testing recommendations in pediatric and adult practice using a survey that was emailed to CF clinicians. There were 58 respondents. Results revealed that 82.5% of pediatric and 36.4% of adult care respondents reported always recommending diagnostic testing for siblings of a newly diagnosed patient. In adult care, another 33.3% reported recommending diagnostic testing if the sibling has symptoms. In pediatric care, whether the sibling had newborn screening was most influential. Most pediatric respondents prefer the sweat chloride test, while 40% in adult practice prefer familial mutation analysis. Perceived barriers included cost, insurance coverage and logistical concerns in both settings, parental emotional state in pediatrics, and concern making recommendations for someone who is not the patient in adult care. Genetic counselors may be able to meet familial needs in CF care, including sibling testing. Many newly diagnosed patients/families do not see a genetic counselor, especially in adult care. These data reveal opportunities for practice guidelines and standardization.

Short-term and long-term response to pulmonary exacerbation treatment in cystic fibrosis.

BACKGROUND: Treatment of pulmonary exacerbations (PEx) in cystic fibrosis (CF) varies widely with no consensus on management practices or best indicators of therapeutic success. To design trials evaluating PEx treatment factors, we characterise the heterogeneity of PEx care in adults and paediatrics, and correlate it with measures of clinical response including short-term and long-term lung function changes, change in symptom severity score and time to next intravenous antibiotic therapy. METHODS: Data were used from a prospective observational study of patients with CF ≥10 years of age enrolled at six sites between 2007 and 2010. All were started on intravenous antibiotics for a clinically diagnosed PEx. Analysis of variance, logistic and Cox regression were used to examine the association of treatment factors with short-term and long-term clinical response. RESULTS: Of 123 patients with CF (60% women, aged 23.1±10.2 years), 33% experienced <10% relative improvement in FEV1 during treatment, which was associated with failing to recover baseline lung function 3 months after treatment (OR=7.8, 95% CI 1.9 to 31.6, p=0.004) and a longer time to next intravenous antibiotic (HR=0.48, 95% CI 0.27 to 0.85, p=0.011). Symptom improvement was observed but was not associated with subsequent lung function or time to next antibiotic therapy, which had a median recurrence time of 143 days. CONCLUSIONS: Immediate symptomatic or respiratory response to PEx treatment did not have a clear relationship with subsequent outcomes such as lung function or intravenous antibiotic-free interval. These results can inform future research of treatment regimens for PEx in terms of interventions and outcome measures. TRIAL REGISTRATION: NCT00788359 (www.clinicaltrials.gov).

Early Life Growth Trajectories in Cystic Fibrosis are Associated with Pulmonary Function at Age 6 Years.

OBJECTIVE: To determine whether severity of lung disease at age 6 years is associated with changes in nutritional status before age 6 within individual children with cystic fibrosis (CF). STUDY DESIGN: Children with CF born between 1994 and 2005 and followed in the CF Foundation Patient Registry from age ≤2 through 7 years were assessed according to changes in annualized weight-for-length (WFL) percentiles between ages 0 and 2 years and body mass index (BMI) percentiles between ages 2 and 6 years. The association between growth trajectories before age 6 and forced expiratory volume in 1 second (FEV1)% predicted at age 6-7 years was evaluated using multivariable linear regression. RESULTS: A total of 6805 subjects met inclusion criteria. Children with annualized WFL-BMI always >50th percentile (N = 1323 [19%]) had the highest adjusted mean (95% CI) FEV1 at 6-7 years (101.8 [100.1, 103.5]). FEV1 at 6-7 years for children whose WFL-BMI increased >10 percentile points by age 6 years was 98.3 (96.6, 100.0). This was statistically significantly higher than FEV1 for children whose WFL-BMI was stable (94.4 [92.6, 96.2]) or decreased >10 percentile points (92.9 [91.1, 94.8]). Among children whose WFL-BMI increased >10 percentile points, achieving and maintaining WFL-BMI >50th percentile at younger ages was associated with significantly higher FEV1 at 6-7 years. CONCLUSIONS: Within-patient changes in nutritional status in the first 6 years of life are significantly associated with FEV1 at age 6-7 years. The establishment of a clear relationship between early childhood growth measurements and later lung function suggests that early nutritional interventions may impact on eventual lung health.

The impact of switching to race-neutral reference equations on FEV1 percent predicted among people with cystic fibrosis.

RATIONALE: The American Thoracic Society recommended switching to race-neutral spirometry reference equations, as race is a social construct and to avoid normalizing disparities in lung function due to structural racism. Understanding the impact of the race-neutral equations on percent predicted forced expiratory volume in one second (ppFEV1) in people with cystic fibrosis (PwCF) will help prepare patients and providers to interpret pulmonary function test results. OBJECTIVE(S): To quantify the impact of switching from Global Lung Initiative (GLI) 2012 race-specific to GLI 2022 Global race-neutral reference equations on the distribution of ppFEV1 among PwCF of different races. METHODS: Cross-sectional analysis of FEV1 among PwCF ages ≥6 years in the 2021 U.S. Cystic Fibrosis Foundation Patient Registry. We describe the absolute difference in ppFEV1 between the two reference equations by reported race and the effect of age and height on this difference. RESULTS: With the switch to GLI Global, ppFEV1 will increase for White (median increase 4.7, (IQR: 3.1; 6.4)) and Asian (2.6 (IQR: 1.6; 3.7)) individuals and decrease for Black individuals (-7.7, (IQR: -10.9; -5.2)). Other race categories will see minimal changes in median ppFEV1. Individuals with higher baseline ppFEV1 and younger age will see a greater change in ppFEV1 (i.e., a greater improvement among White and Asian individuals and a greater decline among Black individuals). CONCLUSIONS: Switching from GLI 2012 race-specific reference equations to GLI 2022 Global race-neutral equations will result in larger reductions in ppFEV1 among Black individuals with CF than increases among White and Asian people with CF.