Browsing by Subject "Cystic fibrosis"
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Item Antibiotic Treatment of Pseudomonas aeruginosa Biofilms Stimulates Expression of mgtE, a Virulence Modulator(2012-08-07) Redelman, Carly Virginia; Anderson, Gregory G.; Blazer-Yost, Bonnie.; Bauer, Margaret.Pseudomonas aeruginosa is a gram negative opportunistic pathogen with the capacity to cause serious disease by forming biofilms, most notably in the lungs of cystic fibrosis (CF) patients. Biofilms are communities of microorganisms that adhere to a solid surface, undergo global regulatory changes, secrete exopolysaccharides, and are innately antibiotic resistant. Virulence modulation is an important tool utilized by P. aeruginosa to propagate infection and biofilm formation in the CF airway. Many different virulence modulatory pathways and proteins have been identified including the protein, MgtE. MgtE has recently been discovered and has been implicated in virulence modulation, as an isogeneic mutation of mgtE leads to increased cytotoxicity. To further elucidate the role of MgtE in P. aerugionsa infections, transcriptional and translational regulation of this protein following antibiotic treatment has been explored. I have demonstrated that mgtE is transcriptionally upregulated following antibiotic treatment of most of the twelve antibiotics tested utilizing RT-PCR and QRT-PCR. A novel model system was employed, which utilizes cystic fibrosis bronchial epithelial (CFBE) cells homozygous for the ΔF508 mutation for these studies. This model system allows P. aeruginosa biofilms to form on CFBE cells modeling the P. aeruginosa in the CF airway. Translational effects of antibiotic treatment on MgtE have been attempted via Western blotting and cytotoxicity assays. Furthermore, to explore the possibility that mgtE is interacting with a known regulatory pathway, a transposon-mutant library was utilized and the regulatory proteins, AlgR and NarX, among others have been identified as possibly interacting with MgtE. Lastly, an MgtE homologue from Staphylococcus aureus was utilized to further demonstrate the virulence modulatory effects of MgtE by demonstrating the expression of the homologue results in decreased cytotoxicity, exactly like expression of the native P. aeruginosa MgtE. This research explores a newly discovered protein that impacts cytotoxicity and biofilm formation and provides valuable information about P. aeruginosa virulence.Item Association between early respiratory viral infections and structural lung disease in infants with cystic fibrosis(Elsevier, 2022) Sanders, Don B.; Deschamp, Ashley R.; Hatch, Joseph E.; Slaven, James E.; Gebregziabher, Netsanet; Kemner-van de Corput, Mariette; Tiddens, Harm A. W. M.; Rosenow, Tim; Storch, Gregory A.; Hall, Graham L.; Stick, Stephen M.; Ranganathan, Sarath; Ferkol, Thomas W.; Davis, Stephanie D.; Pediatrics, School of MedicineBackground: Infants with cystic fibrosis (CF) develop structural lung disease early in life, and viral infections are associated with progressive lung disease. We hypothesized that the presence of respiratory viruses would be associated with structural lung disease on computed tomography (CT) of the chest in infants with CF. Methods: Infants with CF were enrolled before 4 months of age. Multiplex PCR assays were performed on nasal swabs to detect respiratory viruses during routine visits and when symptomatic. Participants underwent CT imaging at approximately 12 months of age. Associations between Perth-Rotterdam Annotated Grid Morphometric Analysis for CF (PRAGMA-CF) CT scores and respiratory viruses and symptoms were assessed with Spearman correlation coefficients. Results: Sixty infants were included for analysis. Human rhinovirus was the most common virus detected, on 28% of tested nasal swabs and in 85% of participants. The median (IQR) extent of lung fields that was healthy based on PRAGMA-CF was 98.7 (0.8)%. There were no associations between PRAGMA-CF and age at first virus, or detection of any virus, including rhinovirus, respiratory syncytial virus, or parainfluenza. The extent of airway wall thickening was associated with ever having wheezed (ρ = 0.31, p = 0.02) and number of encounters with cough (ρ = 0.25, p = 0.0495). Conclusions: Infants with CF had minimal structural lung disease. We did not find an association between respiratory viruses and CT abnormalities. Wheezing and frequency of cough were associated with early structural changes.Item Association between early respiratory viral infections and structural lung disease in infants with cystic fibrosis(Elsevier, 2022-11) Sander, Don B.; Deschamp, Ashley R.; Hatch, Joseph E.; Slaven, James E.; Gebregziabher, Netsanet; Kemner-van de Corput, Mariette; Tiddens, Harm A. W. M.; Rosenow, Tim; Storch, Gregory A.; Hall, Graham L.; Stick, Stephen M.; Ranganathan, Sarath; Ferkol, Thomas W.; Davis, Stephanie D.; Biostatistics and Health Data Science, Richard M. Fairbanks School of Public HealthBackground: Infants with cystic fibrosis (CF) develop structural lung disease early in life, and viral infections are associated with progressive lung disease. We hypothesized that the presence of respiratory viruses would be associated with structural lung disease on computed tomography (CT) of the chest in infants with CF. Methods: Infants with CF were enrolled before 4 months of age. Multiplex PCR assays were performed on nasal swabs to detect respiratory viruses during routine visits and when symptomatic. Participants underwent CT imaging at approximately 12 months of age. Associations between Perth-Rotterdam Annotated Grid Morphometric Analysis for CF (PRAGMA-CF) CT scores and respiratory viruses and symptoms were assessed with Spearman correlation coefficients. Results: Sixty infants were included for analysis. Human rhinovirus was the most common virus detected, on 28% of tested nasal swabs and in 85% of participants. The median (IQR) extent of lung fields that was healthy based on PRAGMA-CF was 98.7 (0.8)%. There were no associations between PRAGMA-CF and age at first virus, or detection of any virus, including rhinovirus, respiratory syncytial virus, or parainfluenza. The extent of airway wall thickening was associated with ever having wheezed (ρ = 0.31, p = 0.02) and number of encounters with cough (ρ = 0.25, p = 0.0495). Conclusions: Infants with CF had minimal structural lung disease. We did not find an association between respiratory viruses and CT abnormalities. Wheezing and frequency of cough were associated with early structural changes.Item Association Between Transient Elastography and Controlled Attenuated Parameter and Liver Ultrasound in Children With Cystic Fibrosis(Wolters Kluwer, 2021-05-13) Ye, Wen; Leung, Daniel H.; Molleston, Jean P.; Ling, Simon C.; Murray, Karen F.; Nicholas, Jennifer L.; Huang, Suiyuan; Karmazyn, Boaz W.; Harned, Roger K.; Masand, Prakash; Alazraki, Adina L.; Navarro, Oscar M.; Otto, Randolph K.; Palermo, Joseph J.; Towbin, Alexander J.; Alonso, Estella M.; Karnsakul, Wikrom W.; Schwarzenberg, Sarah Jane; Seidel, Glenn F.; Siegel, Marilyn; Magee, John C.; Narkewicz, Michael R.; Freeman, A. Jay; Pediatrics, School of MedicineMethods to identify children with cystic fibrosis (CF) at risk for development of advanced liver disease are lacking. We aim to determine the association between liver stiffness measurement (LSM) by vibration-controlled transient elastography (VCTE) with research ultrasound (US) patterns and conventional hepatic markers as a potential means to follow liver disease progression in children with CF. ELASTIC (Longitudinal Assessment of Transient Elastography in CF) is a nested cohort of 141 patients, ages 7-21, enrolled in the Prediction by US of Risk of Hepatic Cirrhosis in CF (PUSH) Study. We studied the association between LSM with research-grade US patterns (normal [NL], heterogeneous [HTG], homogeneous [HMG], or nodular [NOD]) and conventional hepatic markers. In a subgroup (n = 79), the association between controlled attenuation parameter (CAP) and US pattern was explored. Among 133 subjects undergoing VCTE, NOD participants (n = 26) had a significantly higher median (interquartile range) LSM of 9.1 kPa (6.3, 15.8) versus NL (n = 72, 5.1 kPa [4.2, 7.0]; P < 0.0001), HMG (n = 17, 5.9 kPa [5.2, 7.8]; P = 0.0013), and HTG (n = 18, 6.1 kPa [4.7, 7.0]; P = 0.0008) participants. HMG participants (n = 14) had a significantly higher mean CAP (SD) (270.5 dB/m [61.1]) compared with NL (n = 40, 218.8 dB/m [46.5]; P = 0.0027), HTG (n = 10, 218.1 dB/m [60.7]; P = 0.044), and NOD (n = 15, 222.7 dB/m [56.4]; P = 0.041) participants. LSM had a negative correlation with platelet count (rs = − 0.28, P = 0.0071) and positive correlation with aspartate aminotransferase-to-platelet ratio index (rs = 0.38, P = 0.0002), Fibrosis-4 index (rs = 0.36, P = 0.0007), gamma-glutamyltransferase (GGT; rs = 0.35, P = 0.0017), GGT-to-platelet ratio (rs = 0.35, P = 0.003), and US spleen size z-score (rs = 0.27, P = 0.0073). Conclusion: VCTE is associated with US patterns and conventional markers in patients with liver disease with CF.Item Association of Antibiotics, Airway Microbiome, and Inflammation in Infants with Cystic Fibrosis(American Thoracic Society, 2017-10) Pittman, Jessica E.; Wylie, Kristine M.; Akers, Kathryn; Storch, Gregory A.; Hatch, Joseph; Quante, Jane; Frayman, Katherine B.; Clarke, Nadeene; Davis, Miriam; Stick, Stephen M.; Hall, Graham L.; Montgomery, Gregory; Ranganathan, Sarath; Davis, Stephanie D.; Ferkol, Thomas W.; Pediatrics, School of MedicineRATIONALE: The underlying defect in the cystic fibrosis (CF) airway leads to defective mucociliary clearance and impaired bacterial killing, resulting in endobronchial infection and inflammation that contributes to progressive lung disease. Little is known about the respiratory microbiota in the early CF airway and its relationship to inflammation. OBJECTIVES: To examine the bacterial microbiota and inflammatory profiles in bronchoalveolar lavage fluid and oropharyngeal secretions in infants with CF. METHODS: Infants with CF from U.S. and Australian centers were enrolled in a prospective, observational study examining the bacterial microbiota and inflammatory profiles of the respiratory tract. Bacterial diversity and density (load) were measured. Lavage samples were analyzed for inflammatory markers (interleukin 8, unbound neutrophil elastase, and absolute neutrophil count) in the epithelial lining fluid. RESULTS: Thirty-two infants (mean age, 4.7 months) underwent bronchoalveolar lavage and oropharyngeal sampling. Shannon diversity strongly correlated between upper and lower airway samples from a given subject, although community compositions differed. Microbial diversity was lower in younger subjects and in those receiving daily antistaphylococcal antibiotic prophylaxis. In lavage samples, reduced diversity correlated with lower interleukin 8 concentration and absolute neutrophil count. CONCLUSIONS: In infants with CF, reduced bacterial diversity in the upper and lower airways was strongly associated with the use of prophylactic antibiotics and younger age at the time of sampling; less diversity in the lower airway correlated with lower inflammation on bronchoalveolar lavage. Our findings suggest modification of the respiratory microbiome in infants with CF may influence airway inflammation.Item Association of site of treatment with clinical outcomes following intravenous antimicrobial treatment of a pulmonary exacerbation(Elsevier, 2022) Sanders, D. B.; Khan, U.; Heltshe, S. L.; Skalland, M.; West, N. E.; VanDevanter, D. R.; Goss, C. H.; Flume, P. A.; Pediatrics, School of MedicineBackground: In the STOP2 (Standardized Treatment of Pulmonary Exacerbations-2) study, intravenous (IV) antimicrobial treatment duration for adults with cystic fibrosis (CF) experiencing pulmonary exacerbations (PEx) was determined based on initial treatment response. The impact of home vs hospital care remains an important clinical question in CF. Our hypothesis was that STOP2 participants treated at home would have less improvement in lung function compared to those treated in the hospital. Methods: Treating clinicians determined PEx treatment location, which was a stratification factor for STOP2 randomization. Lung function, weight, and symptom recovery were evaluated by treatment location. Propensity scores and inverse probability treatment weighting were used to test for differences in clinical response by treatment location. Results: In all, 33% of STOP2 participants received IV antimicrobials in the hospital only, 46% both in the hospital and at home, and 21% at home only. Mean (95% CI) ppFEV1 improvement was significantly (p < 0.05) lower for those treated at home only, 5.0 (3.5, 6.5), compared with at home and in the hospital, 7.0 (5.9, 8.1), and in the hospital only, 8.0 (6.7, 9.4). Mean weight (p < 0.001) and symptom (p < 0.05) changes were significantly smaller for those treated at home only compared to those treated in the hospital only. Conclusions: Compared to PEx treatment at home only, treatment in the hospital was associated with greater mean lung function, respiratory symptom, and weight improvements. The limitations of home IV therapy should be addressed in order to optimize outcomes for adults with CF treated at home.Item Changes in symptom scores as a potential clinical endpoint for studies of cystic fibrosis pulmonary exacerbation treatment(Elsevier, 2021) VanDevanter, D.R.; Heltshe, S.L.; Sanders, D.B.; West, N.E.; Skalland, M.; Flume, P.A.; Goss, C.H.; Pediatrics, School of MedicineIntroduction: Symptom improvement was assessed as changes in the Chronic Respiratory Infection Symptom Score (CRISS) during intravenous antimicrobial exacerbation treatments among subjects from study NCT02109822. Methods: Median daily CRISS reduction (i.e., improvement) and covariates associated with CRISS reduction by Day 14 were assessed by logistic regression. Results: Among 173 subjects, median baseline CRISS was 49 [IQR 41, 56]; 93.6% had a CRISS reduction of ≥11 (minimal clinically important difference); median time to -11 reduction was 2 days [95% CI 2, 3]. The greatest median CRISS difference from baseline, on Day 17, was -26 [-29, -23]. Odds of -26 CRISS change by Day 14 were greater in subjects with higher baseline CRISS (P=.006) and younger ages (P=.041). Conclusions: CRISS response has good dynamic range and may be a useful efficacy endpoint for PEx interventional trials. The optimal use of CRISS change as an endpoint remains uncharacterized.Item The clinical utility of lung clearance index in early cystic fibrosis lung disease is not impacted by the number of multiple-breath washout trials(European Respiratory Society, 2018-02-16) Foong, Rachel E.; Harper, Alana J.; Skoric, Billy; King, Louise; Turkovic, Lidija; Davis, Miriam; Clem, Charles C.; Rosenow, Tim; Davis, Stephanie D.; Ranganathan, Sarath; Hall, Graham L.; Ramsey, Kathryn A.; Pediatrics, School of MedicineThe lung clearance index (LCI) from the multiple-breath washout (MBW) test is a promising surveillance tool for pre-school children with cystic fibrosis (CF). Current guidelines for MBW testing recommend that three acceptable trials are required. However, success rates to achieve these criteria are low in children aged <7 years and feasibility may improve with modified pre-school criteria that accepts tests with two acceptable trials. This study aimed to determine if relationships between LCI and clinical outcomes of CF lung disease differ when only two acceptable MBW trials are assessed. Healthy children and children with CF aged 3-6 years were recruited for MBW testing. Children with CF also underwent bronchoalveolar lavage fluid collection and a chest computed tomography scan. MBW feasibility increased from 46% to 75% when tests with two trials were deemed acceptable compared with tests where three acceptable trials were required. Relationships between MBW outcomes and markers of pulmonary inflammation, infection and structural lung disease were not different between tests with three acceptable trials compared with tests with two acceptable trials. This study indicates that pre-school MBW data from two acceptable trials may provide sufficient information on ventilation distribution if three acceptable trials are not possible.Item Comparison of Vancomycin Pharmacokinetics in Cystic Fibrosis Patients Pre and Post-lung Transplant:(Sage, 2020-06-15) White, Shannon; Sakon, Colleen; Fitzgerald, Linda; Kam, Charissa; McDade, Erin; Wong, Alanna; School of EducationBackground: Vancomycin is commonly used to treat acute cystic fibrosis (CF) exacerbations associated with methicillin-resistant Staphylococcus aureus (MRSA). Multiple studies have demonstrated pharmacokinetic differences of antimicrobials in the CF population. Very little data exist regarding pharmacokinetics postlung transplant, but 2 studies have noted changes in tobramycin pharmacokinetics. No such studies exist evaluating vancomycin in CF patients postlung transplant. Methods: A retrospective cohort review of CF patients who underwent lung transplantation and received vancomycin pre- and posttransplant was conducted. CF patients who underwent transplant between 2007 and 2016 at 4 medical centers throughout the United States were included. The primary endpoint was the change in elimination rate constant. The secondary endpoints were subgroup analyses of patients grouped by age, time posttransplant, and number of nephrotoxic medications. Results: A total of 25 patients were included, of which just under half were pediatric. Patients were significantly older and heavier posttransplant and had higher serum creatinine and number of nephrotoxic medications. The change in elimination rate constant from pre- to posttransplant was −0.50 hr−1 which was statistically significant (P < .001). This significant decrease was consistent among all subgroups of patients evaluated with the exception of pediatric patients. Conclusion: Vancomycin pharmacokinetics are significantly altered in CF patients in the posttransplant setting as evidenced by a decrease in elimination rate constant. This decrease may be related to a decrease in renal clearance and higher numbers of nephrotoxic medications posttransplant. Regardless, pretransplant vancomycin regimens may not predict appropriate posttransplant regimens.Item Cystic fibrosis related diabetes (CFRD) prognosis(Elsevier, 2021-11-19) Sandouk, Zahrae; Khan, Farah; Khare, Swapnil; Moran, Antoinette; Medicine, School of MedicineCystic fibrosis related diabetes (CFRD) occurs in at least 40-50% of adults with CF. With other forms of diabetes, microvascular and macrovascular disease are the major causes of morbidity and mortality. Macrovascular disease is rare in CF. While microvascular disease does occur in this population, there are CF-specific diabetes complications that have a more important impact on prognosis. The additional diagnosis of diabetes in CF is associated with decreased lung function, poor nutritional status, and an overall increase in mortality from lung disease. These negative findings start even before the clinical diagnosis of CFRD, during the period when patients experience abnormal glucose tolerance related to insulin insufficiency. The main mechanisms by which CFRD negatively affects prognosis are thought to be a combination of 1) protein catabolism, decreased lean body mass and undernutrition resulting from insulin insufficiency, and 2) an increased pro-inflammatory and pro-infectious state related to intermittent hyperglycemia. With the introduction of CFTR modulators, the care of CF patients has been revolutionized and many aspects of CF health such as BMI and lung function are improving. The impact of these drugs on the adverse prognosis related to the diagnosis of diabetes in CF, as well as the potential to delay or prevent onset of CFRD remain to be determined.