[Show abstract][Hide abstract] ABSTRACT: The impact of infection with Burkholderia gladioli in cystic fibrosis, other chronic airway diseases and immunosuppressed patients is unknown.
A six-year retrospective review of all patients with B. gladioli infection was performed in a tertiary referral center with cystic fibrosis and lung transplantation programs. In addition, a targeted survey of all 251 lung transplant recipients was performed. Available B. gladioli isolates were analyzed via pulsed field gel electrophoresis.
Thirty-five patients were culture positive for B. gladioli, including 33 CF patients. No bacteremia was identified. Isolates were available in 18 patients and all were genetically distinct. Two-thirds of these isolates were susceptible to usual anti-pseudomonal antibiotics. After acquisition, only 40% of CF patients were chronically infected (> or =2 positive cultures separated by at least 6 months). Chronic infection was associated with resistance to > or =2 antibiotic groups on initial culture and failure of eradication after antibiotic therapy. The impact of acquisition of B. gladioli infection in chronic infection was variable. Three CF patients with chronic infection underwent lung transplantation. One post-transplant patient developed a B. gladioli mediastinal abscess, which was treated successfully.
The majority of patients' culture positive for B. gladioli at our center have CF. B. gladioli infection is often transient and is compatible with satisfactory post-lung transplantation outcomes.
[Show abstract][Hide abstract] ABSTRACT: Over a 6-year period, Burkholderia cepacia complex species were isolated from cystic fibrosis (CF) patients receiving care at The University of North Carolina Hospitals (clinic CF patients) and from those referred from other treatment centers. Fifty-six isolates collected from 30 referred patients and 26 clinic CF patients were characterized by pulsed-field gel electrophoresis (PFGE) and were assayed by PCR to detect the cable pilin gene, cblA. PFGE results indicated that six separate clusters (clusters A to F) were present among the 56 isolates and that three clusters (clusters A, B, and E) consisted only of isolates from referred patients infected with B. cepacia complex isolates prior to referral. However, one cluster (cluster C) consisted of isolates from four CF patients, and hospital records indicate that this cluster began with an isolate that came from a referred patient and that spread to three clinic CF patients. Cluster D consisted of two isolates from clinic CF patients, and hospitalization records are consistent with nosocomial, patient-to-patient spread. cblA was present in only 4 of the 56 isolates and included isolates in cluster E from the referred patients. Our results indicate a lack of spread of a previously characterized, transmissible clone from referred patients to our clinic CF population. Only two instances of nosocomial, patient-to-patient spread could be documented over the 6-year period. An additional spread of an isolate (cluster F) from a referred patient to a clinic patient could not be documented as nosocomial and may have been the result of spread in a nonhospitalized setting. The majority (36 of 56) of our B. cepacia complex-infected CF patients harbor isolates with unique genotypes, indicating that a diversity of sources account for infection. These data suggest that CF patients infected with B. cepacia complex and referred for lung transplantation evaluation were not a major source of B. cepacia complex strains that infected our resident CF clinic population.
Full-text · Article · May 2002 · Journal of Clinical Microbiology
[Show abstract][Hide abstract] ABSTRACT: Gene transfer is an attractive option to treat the basic defect in cystic fibrosis. In a double-blind, placebo-controlled, rising-dose tolerance study in the nasal epithelium, we tested the safety and efficacy of a cationic liposome [p-ethyl-dimyristoylphosphadityl choline (EDMPC) cholesterol] complexed with an expression plasmid containing hCFTR cDNA. Eleven adult CF patients were studied in a protocol that allowed comparisons within individual subjects: vector and placebo were sprayed into alternate nostrils at intervals over 7 h. After dosing, vector-specific DNA was present in nasal lavage of all subjects for up to 10 days. There were no adverse events. The vector-treated epithelium did not exhibit a significant increase in CFTR-mediated Cl- conductance from baseline and was not different from the placebo-treated nostril: mean deltaCFTR Cl- conductance, mV +/- SEM, -1.6+/-0.4 vs -0.6+/-0.4, respectively. CFTR-mediated Cl- conductance increased toward normal during repetitive nasal potential difference measurements over the 3 days before dosing which influenced the postdosing calculations. No vector-specific mRNA was detected in the nasal epithelial scrape biopsies, although endogenous CFTR mRNA was detected in all subjects. We conclude that the lipid-DNA complex is safe, but did not produce consistent evidence of gene transfer to the nasal epithelium by physiologic or molecular measures.
Full-text · Article · Feb 2000 · Molecular Therapy
[Show abstract][Hide abstract] ABSTRACT: GTAB1001: A Double-Blind, Placebo Controlled, Dose Ranging Study to Evaluate the Safety and Biological Efficacy of the Lipid-DNA Complex GR213487B in the Nasal Epithelium of Adult Patients with Cystic Fibrosis. OBJECTIVES: To evaluate the effectiveness of various dosages of the lipid-DNA complex GR213487B (0.4375mg and either 4.0mg or 0.0625mg) for producing CFTR gene transfer and correcting the chloride ion transport defect in the nasal epithelium of patients with cystic fibrosis. To assess the safety and tolerability of the lipid-DNA complex GR213487B when applied to the nasal epithelium of patients with cystic fibrosis. DESIGN: Single-center, double-blind, placebo controlled, dose ranging study. DURATION: Pre-treatment evaluations will be performed during two outpatient study visits (ie. between Day -7 to -3 and at Day -2). Patients will be admitted to the Clinical Research Unit (CRU) at the University of North Carolina at Chapel Hill on Day -1 for additional pre-treatment evaluations performed the day prior to administration of double-blind treatment (ie. gene transfer) on Treatment Day 0. Patients will remain in the CRU for 7 days (Day -1 to Day 6) and will be discharged on Day 6. Patients will subsequently be followed on an outpatient basis but will return for another assessment between Days 9-11, and may also return to the CRU for two optional study visits on Days 14 and 21. All patients will return to the CRU on an out-patient basis for follow-up evaluations on Day 28 +/- 3. SETTING: Patients will receive in-patient treatment in the CRU at the University of North Carolina at Chapel Hill and will remain in the CRU for 7 days. PATIENTS: A target enrollment of 12 evaluable patients is planned. STUDY TREATMENTS: Patients who meet all entry criteria will complete pre-treatment assessments, which will take place between Day -7 to Day -1, and will serve as a baseline for specific evaluations and to ensure clinical stability. Patients will return on Day -1 for admission to the CRU the day prior to gene transfer. Each nostril of the patients will be randomly assigned in a double blind manner to receive either GR213487B liquid nasal spray or the lipid alone (ie. control administered as liposome), by topical application directed at the inferior turbinate. The first four patients will receive an initial dosage of GR213487B containing 0.4375 mg of DNA. The decision to proceed to administer a higher dose (ie. 4.0mg DNA) or a lower dose (ie. 0.0625mg DNA) in the subsequent eight patients will be determined by the Principal Investigator in association with an FDA officer serving as an independent Clinical Ombudsman, according to the study plan (see Section 5.5 and Appendix 3-Dosing Flow Chart). MEASUREMENTS: Efficacy Evaluations The primary variables to determine the efficacy of transgene expression will be: * Evidence of vector derived CFTR (cystic fibrosis transmembrane conductance regulator) mRNA, as measured by reverse transcriptase polymerase chain reaction (RT-PCR) in nasal epithelial cells obtained from nasal scrapes on Day 3 and, nasal biopsies on Day 5, if sufficient tissue is available. * Correction of chloride ion transport across the nasal epithelium as measured by the transepithelial electrical potential difference (TEPD). The baseline TEPD will initially be measured, and again subsequently following perfusion of: --zero chloride perfusion containing amiloride (to induce chloride secretion) --zero chloride perfusion containing amiloride and isoproterenol (to increase cAMP-mediated chloride secretion) Secondary measures to determine the efficacy of gene transfer will be: * Evidence of delivery of plasmid DNA in the nasal lavage (Day 1-5, Day 9-11 and Day 28) * Evidence of vector derived CFTR mRNA from nasal scrapes performed after the nasal biopsy (ie. Day 9-11 and/or Day 28) * Percentage of cells from nasal biopsies expressing vector derived CFTR mRNA as measured by in situ hybridization * Evidence of vector derived CFTR
No preview · Article · Feb 1998 · Human Gene Therapy
[Show abstract][Hide abstract] ABSTRACT: To compare the pharmacokinetics and systemic exposure of nebulized and oral amiloride in adolescents and adults with mild to moderate cystic fibrosis (CF).
Open-label, randomized, two-way crossover, single-dose pharmacokinetic study.
University hospital clinical research unit.
Nine adolescents and 10 adults with mild to moderate CF (forced expiratory volume in 1 sec > or = 50% predicted, Brasfield score > or = 15).
Patients received amiloride solution orally (10 mg of amiloride 1-mg/ml solution) and by inhalation [4.5 ml amiloride of 1-mg/ml solution in 12% saline (approximately 3.8 mmol/L) by DeVilbiss 646 nebulizer] during two study phases separated by a 7- to 28-day washout period. Serial blood and urine samples were collected for 48 and 72 hours, respectively.
After oral dosing, the mean +/- SD maximum peak concentration (Cmax) was 20.6 +/- 10.0 ng/ml at 3.2 +/- 1.2 hours in adults and 21.7 +/- 4.88 at 2.9 +/- 0.6 hours in the adolescents. Mean area under the concentration-time curve (AUC) from time zero to infinity hours was 275 +/- 115 and 254 +/- 60 ng.hr/ml in the adult and adolescent groups; half-life was 16.0 +/- 0.7 and 13.4 +/- 1.4 hours, respectively. After nebulization, 14 of 19 subjects exhibited two concentration peaks (Cmax1 and Cmax2) with mean values of 1.57 +/- 1.67 ng/ml at 0.5 +/- 0.2 hours and 1.37 +/- 1.21 ng/ml at 4.0 +/- 1.0 hours for adults, and 1.49 +/- 0.99 ng/ml at 0.5 +/- 0.1 hours and 1.52 +/- 0.81 ng/ml at 3.3 +/- 0.5 hours for adolescents. Estimated mean +/- SD dose nebulized was 1.91 +/- 0.66 and 2.28 +/- 0.30 mg in the adult and adolescent groups, respectively. Mean +/- SD AUC from time zero to the last measurable plasma amiloride concentration after inhalation was 14.4 +/- 17.6 and 15.4 +/- 10.1 ng.hr/ml in the adults and adolescents. No significant adverse events occurred during the study. Pharmacokinetic parameters were not statistically different between the adolescent and adult groups by route of administration. However significant differences in peak amiloride concentration, AUC, and urinary amiloride excretion were evident when comparing oral versus inhalation administration within each group.
Mean amiloride plasma concentration peaks and AUC after inhalation were significantly lower than after oral dosing. In addition, the second amiloride plasma concentration peak may be due to oral ingestion of the nebulized amiloride, whereas the earlier Cmax1 after inhalation may be due to pulmonary absorption of amiloride. These results suggest that single-dose amiloride inhalation in patients with mild to moderate CF results in minimal systemic exposure compared with oral dosing, and that drug disposition is similar in adolescents and adults with CF.
[Show abstract][Hide abstract] ABSTRACT: Impaired mucociliary clearance contributes to the pathophysiology of several airways diseases including cystic fibrosis, asthma, and chronic bronchitis. Extracellular triphosphate nucleotides (adenosine 5'-triphosphate [ATP], uridine 5'-triphosphate [UTP]) activate several components of the mucociliary escalator, suggesting they may have potential as therapeutic agents for airways diseases. We conducted initial (Phase I) studies of acute safety and efficacy of aerosolized UTP alone and in combination with aerosolized amiloride, the sodium channel blocker, in normal human volunteers. Safety was assessed by measurement of pulmonary function. Neither UTP alone nor in combination with amiloride caused any clinically significant adverse effects on airway mechanics, (subdivisions of) lung volumes, or gas exchange. Acute efficacy of UTP and amiloride alone and in combination, was assessed by measuring changes in the clearance of inhaled radiolabeled particles. A 2.5-fold increase in mucociliary clearance was seen in response to UTP alone and in combination with amiloride. We conclude that aerosolized UTP +/- amiloride clearly enhances mucociliary clearance without acute adverse effects in normal adults, and may have therapeutic potential to enhance airways clearance in diseases characterized by retained airways secretions.
No preview · Article · Aug 1996 · American Journal of Respiratory and Critical Care Medicine
[Show abstract][Hide abstract] ABSTRACT: Cystic fibrosis (CF) is characterized by abnormal airway epithelial electrolyte transport leading to viscous airway secretions that are difficult to clear. By enhancing Cl- secretion onto and blocking Na+ absorption from the airway surface, treatment with aerosolized uridine 5'-triphosphate (UTP) plus amiloride may improve the rheology of airway secretions and enhance mucociliary clearance in patients with CF. After performing safety studies of aerosolized UTP/amiloride in adult patients with CF, we investigated the effects of inhaled vehicle and UTP/amiloride on mucociliary clearance of [99mTc] iron oxide particles from the airways of adult patients with CF (n = 14). We found no clinically significant adverse effects from inhalation of therapeutic doses of UTP/amiloride. Mean baseline peripheral clearance rates during the first 40 min of clearance measurements were significantly less in patients with CF than in normal subjects (mean +/- SE: 0.30 +/- 0.05 versus 0.54 +/- 0.07%/min, respectively; p = 0.01). Aerosolized UTP and amiloride in combination improved mucociliary clearance from the peripheral airways of the CF lungs to near normal values (0.51 +/- 0.09%/min; p = 0.04) during this period. These data support the concept for the use of UTP in combination with amiloride as therapy to improve clearance of secretions from the lungs of patients with CF.
No preview · Article · Jul 1996 · American Journal of Respiratory and Critical Care Medicine
[Show abstract][Hide abstract] ABSTRACT: Cystic fibrosis is a monogenic disease that deranges multiple systems of ion transport in the airways, culminating in chronic infection and destruction of the lung. The introduction of a normal copy of the cystic fibrosis transmembrane conductance regulator (CFTR) gene into the airway epithelium through gene transfer is an attractive approach to correcting the underlying defects in patients with cystic fibrosis. We tested the feasibility of gene therapy using adenoviral vectors in the nasal epithelium of such patients.
An adenoviral vector containing the normal CFTR complementary DNA in four logarithmically increasing doses (estimated multiplicity of infection, 1, 10, 100, and 1000), or vehicle alone, was administered in a randomized, blinded fashion to the nasal epithelium of 12 patients with cystic fibrosis. Gene transfer was quantitated by molecular techniques that detected the expression of CFTR messenger RNA and by functional measurements of transepithelial potential differences (PDs) to assess abnormalities of ion transport specific to cystic fibrosis. The safety of this treatment was monitored by nasal lavage and biopsy to assess inflammation and vector replication.
The adenoviral vector was detected in nasal-lavage fluid by culture, the polymerase chain reaction (PCR), or both in a dose-dependent fashion for up to eight days after vector administration. There was molecular evidence of gene transfer by reverse-transcriptase PCR assays or in situ hybridization in five of six patients treated at the two highest doses. However, the percentage of epithelial cells transfected by the vector was very low (< 1 percent), and measurement of PD across the epithelium revealed no significant restoration of chloride transport or normalization of sodium transport. At the lower doses of vector, there were no toxic effects. However, at the highest dose there was mucosal inflammation in two of three patients.
In patients with cystic fibrosis, adenoviral-vector-mediated transfer of the CFTR gene did not correct functional defects in nasal epithelium, and local inflammatory responses limited the dose of adenovirus that could be administered to overcome the inefficiency of gene transfer.
Preview · Article · Oct 1995 · New England Journal of Medicine
[Show abstract][Hide abstract] ABSTRACT: Cystic fibrosis (CF) is a recessive genetic disease reflecting mutations in the gene coding for the CF transmembrane regulator (CFTR) protein, which normally functions as a cyclic adenosine monophosphate (cAMP)-regulated chloride (Cl-) channel. Functional abnormalities include thick airway secretions resulting from defective cAMP-mediated Cl- (liquid) secretion and a related defect, excessive sodium (Na+) (liquid) absorption. Novel pharmacologic agents are being tested as therapy for these ion transport defects. Aerosolized amiloride inhibits excessive Na+ absorption, and pilot studies in adult patients with CF show slowing of the disease-associated decline in lung function. Clinical trials of amiloride are currently underway in adults and adolescents, and short-term safety studies have been initiated in children. Aerosolized uridine triphosphate (UTP) induces Cl- (and liquid) secretion in CF airway epithelia via non-CFTR Cl- channels. Short-term aerosolized UTP is well tolerated by normal subjects and patients with CF, and pilot studies in normal subjects show that aerosolized UTP is an effective stimulator of mucociliary clearance. Pharmacotherapy that modifies airway epithelial ion transport may provide new opportunities for treatment of CF lung disease.