Determining the minimal clinically important difference for the questionnaire of olfactory disorders in people with cystic fibrosis and factors associated with improvement after highly effective modulator therapy.

INTRODUCTION: Olfactory dysfunction (OD) is common among people with cystic fibrosis (PwCF). The Questionnaire of Olfactory Disorders (QOD) is a validated instrument that evaluates olfactory-specific quality-of-life. The QOD minimal clinically important difference (MCID) and factors associated with olfactory improvement after elexacaftor/tezacaftor/ivacaftor have not been determined for PwCF. METHODS: Prospective observational data were pooled from three studies that enrolled adult PwCF with chronic rhinosinusitis (CRS). QOD scores and disease characteristics were assessed. To evaluate internal consistency and calculate the QOD MCID, Cronbach's alpha and four distribution-based methods were employed. For participants who enrolled prior to elexacaftor/tezacaftor/ivacaftor, QOD scores were obtained at baseline and after elexacaftor/tezacaftor/ivacaftor initiation. Multivariable regression was used to identify factors associated with QOD improvement. RESULTS: Of 129 PwCF included, 65 had QOD scores before and 3-6 months after starting elexacaftor/tezacaftor/ivacaftor. Mean baseline QOD score was 6.5 ± 7.9. Mean Cronbach's alpha was ≥0.85. The MCID estimates were as follows: Cohen's effect size = 1.6, standard error of measurement = 2.5, ½ baseline standard deviation = 4.0, and minimal detectable change = 6.9. Mean MCID was 3.7. Of those with pre/post elexacaftor/tezacaftor/ivacaftor QOD scores, the mean change in QOD was -1.3 ± 5.4. After elexacaftor/tezacaftor/ivacaftor, QOD improvement surpassed the MCID in 22% of participants (14/65). Worse baseline QOD scores and nasal polyps were associated with improved QOD scores after elexacaftor/tezacaftor/ivacaftor (both p < 0.04). CONCLUSION: The QOD MCID in PwCF was estimated to be 3.7. Elexacaftor/tezacaftor/ivacaftor led to qualitative but not clinically meaningful improvements in QOD score for most PwCF; PwCF with worse baseline QOD scores and nasal polyps improved in a clinically significant manner.

The gut microbiome, short chain fatty acids, and related metabolites in cystic fibrosis patients with and without colonic adenomas.

BACKGROUND: Adults with cystic fibrosis (CF) are at increased risk for colon cancer. CF patients have reductions in intestinal bacteria that produce short chain fatty acids (SCFAs), although it is unclear whether this corresponds with intestinal SCFA levels and the presence of colonic neoplasia. The aim of this study was to compare gut microbiome and SCFA composition in patients with and without CF, and to assess associations with colonic adenomas. METHODS: Colonic aspirates were obtained from adults with and without CF undergoing colon cancer screening or surveillance colonoscopy. Microbiome characterization was performed by 16S rRNA V3-V4 sequencing. Targeted profiling of SCFAs and related metabolites was performed by LC-MS. RESULTS: 42 patients (21 CF, 21 control) were enrolled. CF patients had significantly reduced alpha diversity and decreased relative abundance of many SCFA-producing taxa. There were no significant differences in SCFA levels in CF patients, although there were reduced levels of branched chain fatty acids (BCFAs) and related metabolites. CF patients with adenomas, but not controls with adenomas, had significantly increased relative abundance of Bacteroides fragilis. CF microbiome composition was significantly associated with isovalerate concentration and the presence of adenomas. CONCLUSIONS: CF patients have marked disturbances in the gut microbiome, and CF patients with adenomas had notably increased relative abundance of B. fragilis, a pathogen known to promote colon cancer. Reductions in BCFAs but not SCFAs were found in CF. Further studies are warranted to evaluate the role of B. fragilis as well the biological significance of reductions in BCFAs in CF.

Laryngeal Injury Due to Amikacin Inhalation for Refractory Mycobacterium avium Complex Infection.

Inhaled antibiotics have long been used for chronic lung infections, especially in patients with cystic fibrosis and increasingly for non-cystic fibrosis bronchiectasis. Amikacin liposome inhalation suspension (ALIS) has emerged as a promising treatment for Mycobacterium avium complex infection refractory to oral antibiotics. However, despite its efficacy, nearly one-half of patients in phase II and III trials experienced dysphonia as a treatment-associated adverse effect. Here, we describe a patient who experienced severe, acute-onset laryngitis while receiving ALIS for refractory M avium complex infection, prompting discontinuation of ALIS therapy. This is the first report directly describing vocal fold injury due to such therapy. Given the high frequency of dysphonia reported with ALIS, this case highlights the potential severity of laryngeal toxicity, the importance of coordination of care for patients receiving inhaled antibiotics for chronic pulmonary disease, and the need for better insight into mechanisms of toxicity.

Telerehabilitation Using Fitness Application in Patients with Severe Cystic Fibrosis Awaiting Lung Transplant: A Pilot Study.

PURPOSE: The purpose of this study was to pilot a home-based pulmonary rehabilitation (PR) program administered via a telemedicine approach using a combination of fitness application and self-selected activity in lung transplant candidates with cystic fibrosis (CF). METHODS: We recruited adult patients with CF. The main outcome was adherence, measured by number of sessions completed in 12 weeks. Secondary outcomes were adverse events, six-minute walk distance (6MWD), and dyspnea. Participants were provided a personalized exercise program and equipment including a fitness application that provided exercise videos, recorded exercise time, and corresponding heart rate. We reviewed data daily and provided text messages with feedback. We compared our study outcomes to a retrospective data set of CF patients who participated in a 24-session outpatient hospital-based PR program. Data presented as mean ± standard deviation. RESULTS: Eleven patients participated in the home PR program, 45% female, age 33 ± 7 years, FEV1 27 ± 5% predicted. Sessions completed were 19 ± 12 home-based PR vs. 9 ± 4 hospital-based PR, p = .03. Fifty percent of the home-based group completed ≥24 sessions in 12 weeks versus 0% of the hospital-based patients (p = .03). There were no adverse events during exercise. Completers of the home-based program demonstrated a clinically meaningful lower decline in 6 MWD than noncompleters (6MWD -7 ± 15 vs. -86 ± 108 meters). Only one participant performed a post 6 MWD in the hospital-based PR. CONCLUSION: Patients with severe CF demonstrated adherence to home PR delivered using fitness application and self-selected activity with no adverse events. This program style may be a viable solution for telerehabilitation in severe CF and is particularly relevant in the COVID era.

Pseudomonas aeruginosa Susceptibility Patterns and Associated Clinical Outcomes in People with Cystic Fibrosis following Approval of Aztreonam Lysine for Inhalation.

The approval of aztreonam lysine for inhalation solution (AZLI) raised concerns that additional antibiotic exposure would potentially affect the susceptibility profiles of Pseudomonas aeruginosa isolates from cystic fibrosis (CF) patients. This 5-year, prospective, observational study tracked susceptibility changes and clinical outcomes in CF patients in the United States with chronic P. aeruginosa infection. Sputum cultures were collected annually (2011 to 2016). The primary study endpoint was the proportion of subjects whose least susceptible P. aeruginosa isolate had an aztreonam MIC that was >8 µg/ml (parenteral breakpoint) and increased ≥4-fold compared with the least susceptible isolate from the previous year. Annualized data for pulmonary exacerbations, hospitalizations, and percent of predicted forced expiratory volume in 1 s (FEV1% predicted) were obtained from the CF Foundation Patient Registry and compared between subjects meeting and those not meeting the primary endpoint. A total of 510 subjects were enrolled; 334 (65%) completed the study. A consistent proportion of evaluable subjects (13 to 22%) met the primary endpoint each year, and AZLI use during the previous 12 months was not associated with meeting the primary endpoint. While the annual declines in lung function were comparable for subjects meeting and those not meeting the primary endpoint, more pulmonary exacerbations and hospitalizations were experienced by those who met it. The aztreonam susceptibility of P. aeruginosa remained consistent during the 5-year study. The relationship between P. aeruginosa isolate susceptibilities and clinical outcomes is complex; reduced susceptibility was not associated with an accelerated decline in lung function but was associated with more exacerbations and hospitalizations, likely reflecting increased overall antibiotic exposure. (This study has been registered at ClinicalTrials.gov under identifier NCT01375036.).

Adults with cystic fibrosis have deficits in bone structure and strength at the distal tibia despite similar size and measuring standard and relative sites.

Individuals with cystic fibrosis (CF) have lower bone mineral density (BMD) by DXA and are at higher risk of fracture than healthy controls. However, the 2-dimensional measurement of areal BMD (aBMD) provided by DXA is influenced by bone size and the true extent of the bone deficit is unclear. Our objective was to use high-resolution peripheral quantitative computed tomography (HR-pQCT) and individual trabecula segmentation (ITS) analysis to compare volumetric BMD (vBMD), microarchitecture and estimated strength at the distal radius and tibia in 26 young adults with CF and 26 controls matched for age, gender, and race. To assess the effect of limb length and minimize the confounding effects of size on HR-pQCT outcomes, we scanned participants at both the standard fixed HR-pQCT measurement sites and at a subject-specific relative site that varied according to limb length. CF participants did not differ significantly in age, height, weight, or BMI from controls. Ulnar and tibial lengths were 9mm shorter in CF patients, though differences were not significant. CF patients had significantly lower BMI-adjusted aBMD by DXA at the lumbar spine (8.9%, p<0.01), total hip (11.5%, p<0.01) and femoral neck (14.5%, p<0.01), but not at the forearm. At the fixed radius site, thickness of trabecular plates and torsional stiffness were significantly lower in CF participants than controls. At the relative radius site, only torsional stiffness was significantly lower in CF participants. At the tibia, total, trabecular and cortical vBMD were significantly lower at both fixed and relative sites in CF participants, with fewer, more widely-spaced trabecular plates, lower trabecular connectivity, and lower axial and torsional stiffness. Our results confirm that aBMD is lower at the spine and hip in young adults with CF, independent of BMI and body size. We also conclude that vBMD and stiffness are lower at the weight-bearing tibia. The pathogenesis of these differences in bone density and strength at the tibia appear to be related to trabecular drop-out and reduced trabecular connectivity and to be independent of differences in limb length, as assessed by scanning participants at both standard and relative sites. We concluded that significant deficits in bone structure and strength persist in young adults with CF, despite advances in care that permit them to attain relatively normal height and weight.

Classic respiratory disease but atypical diagnostic testing distinguishes adult presentation of cystic fibrosis.

BACKGROUND: The majority of new cases of cystic fibrosis (CF) are diagnosed before age 2 years. Diagnoses in older individuals have increased because of improved genetic testing and increased awareness of the disease. A comprehensive description of clinical, genetic, and microbiologic characteristics of adult-age presentation of CF does not exist. We compare newly diagnosed CF in adults with newly diagnosed CF in children and adolescents in the United States. METHODS: This is a cross-sectional study of new CF diagnoses from the Cystic Fibrosis Foundation Patient Registry between 1995 and 2005. Diagnostic, microbiologic, and clinical features during year of diagnosis were analyzed for subjects by age group. Descriptive statistics were calculated for variables on characteristics by age group. RESULTS: A total of 9,766 new diagnoses of CF were reported to the Registry between 1995 and 2005. The proportion of adult diagnoses increased significantly in the years 2001 to 2005 as compared with 1995 to 2000 (9.0% vs 7.7%, P = .012). FEV(1)% predicted decreased with increasing age at diagnosis (P < .001). Infection with Pseudomonas aeruginosa was most common in adults (P < .001). Both the number of positive sweat chloride tests and prevalence of DeltaF508 mutation, the most common mutation in the United States, decreased significantly with older age at diagnosis (P < .001). CONCLUSIONS: Between 1995 and 2005, the proportion of new diagnoses of CF in adults in the United States increased significantly. Adults present with commonly described CF respiratory disease (Pseudomonas aeruginosa infection and reduced lung function), but have lower sweat chloride values and lower frequency of DeltaF508 mutation. Knowledge of clinical characteristics and diagnostic limitations of adult patients presenting with CF will hopefully lead to earlier recognition and intervention.