Human gene marker/therapy clinical protocols.
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Biomedical subjects
Publications and source records attributed to R W Wilmott.
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To define the toxicity of cystic fibrosis transmembrane conductance regulator gene (CFTR) gene therapy with a replication-deficient recombinant adenovirus (Av1Cf2) in a nonhuman primate model, 10(10) plaque forming units (pfu) were instilled directly through a bronchoscope into the right lung of 5 macaques, and a lower dose of 4 x 10(6) pfu was administered to the right lung of 1 macaque. One sham-treated control received phosphate-buffered saline (PBS). The macaques were evaluated sequentially by clinical examination, vital signs, weight, hematology, blood chemistry, chest radiography, pulse oximetry, and bronchoalveolar lavage (BAL) at baseline and 3-28 days post-treatment. After the period of observation, macaques were sacrificed for autopsy and histological examination. The macaques tolerated the experimental therapy clinically with no changes in body temperature, oxygen saturation, heart rate, body weight, or blood pressure. However, 1 macaque with visible evidence of aspiration at the time of initial bronchoscopy developed tachypnea with right lower lobe (RLL) pneumonia on chest radiograph and by histology. There were no changes in Hgb, Wbc, BUN, plasma electrolytes, bilirubin, or hepatic transaminases. In the macaques that received 10(10) pfu, there was a progressive increase in the number of CD8+ lymphocytes in BAL that was maximal at 28 days. Histological examination of the treated lungs of the high-dose macaques at 3 days showed marked peribronchial and perivascular cuffing by inflammatory cells and alveolar accumulation of neutrophils and macrophages. The alveolitis appeared to be resolving at 28 days, although the perivascular and peribronchial aggregates of mononuclear cells were still present. In the high-dose macaques, BAL interleukin-8 (IL-8) was increased at all time points (256-388 pg/ml versus 1-84 pg/ml at baseline and in control), whereas IL-1 beta was increased only at days 21 and 28 (341-852 pg/ml versus 30-92 pg/ml at baseline and in control). There were no increases in BAL cell counts, IL-1 beta or IL-8, and histological changes were mild in the macaque that received 4 x 10(6) pfu. Evaluation for Av1Cf2-derived human CFTR expression using RS-PCR demonstrated expression at 3, 10, and 21, but not 28 days in macaques treated with 10(10) pfu of Av1Cf2. In situ hybridization analysis demonstrated human CFTR mRNA in the alveolar regions of the lobes that received the vector at 10 and 21 days. There was no evidence of expression after treatment with 4 x 10(6) pfu. This study showed that high-dose adenoviral vector administration to the lung achieved CFTR gene transfer and expression but was associated with increased concentrations of cytokines in BAL and alveolar inflammation. A low dose, equivalent to the maximum clinical dose currently proposed for phase I trials in human subjects, was not associated with cellular or cytokine evidence of inflammation, and histological abnormalities were mild.
Surfactant replacement therapy may have a role in the treatment of ARDS in children. The current studies suggest that rapid instillation of exogenous surfactant is more effective than slow tracheal instillation or aerosolized delivery. Studies suggest that exogenous surfactant given early in the development of ARDS is more effective than therapy provided late in the course of the disease. Natural surfactants appear to be more effective than artificial surfactants due to the presence of SP-B and SP-C, which prevent inhibition of the exogenous surfactant by the protein leakage into the alveolus that is characteristic of ARDS. Exogenous surfactant replacement therapy appears to be safe and well tolerated. A surfactant that can be delivered by aerosol would be useful since this is more easily tolerated by the patients, requires less surfactant, and would be more cost effective when compared with tracheal instillation. Aerosolized surfactant could be given to patients who have not yet required mechanical ventilation, thus potentially preventing the progression of the acute lung injury to respiratory failure. The recent failure of a large multi-center trial of aerosolized Exosurf for the treatment of sepsis-related ARDS72 may have been due to the failure of the delivery system as opposed to the surfactant used in the trial; therefore, further research into aerosol delivery systems is needed. There may be different responses to exogenous surfactant therapy by patients with ARDS of different etiologies, such as aspiration pneumonia, sepsis, or trauma. Well-planned placebo-controlled trials will be required to determine these differences. The data supporting the role of surfactant replacement for the treatment of ARDS in children is growing. However, before widespread use of surfactant is considered, a multi-center, placebo-controlled trial will be required to establish the safety and efficacy of surfactant replacement in such patients.
To further investigate the early course of cystic fibrosis (CF), specifically to examine factors contributing to energy imbalance, we examined resting energy expenditure (REE) (by indirect calorimetry) per unit body weight and metabolically active body cell mass (by total body potassium), in relation to CF genotype (by genomic DNA analysis), CF pancreatic phenotype, and markers of pulmonary inflammation (from bronchoalveolar lavage fluid). Eighteen subjects with presymptomatic CF who were less than 2 years of age (n = 11, delta F508/ delta F508 genotype; n = 15, pancreatic insufficiency phenotype), identified by newborn screening, were compared with age-, sex-, and length-matched control subjects (n = 13). Those with the delta F508/ delta F508 genotype had significantly higher mean REE expressed per unit body weight (125%) and body cell mass (115%; p < 0.03). Those with other genotypes (n = 7) did not, as a group, have significantly different mean REEs, but individuals with known "severe" genotypes had REEs in the high range and those with a pancreatic-sufficient phenotype had significantly lower REE than those with a pancreatic-insufficient phenotype (p < 0.05), and REEs were in the normal range. Examination of bronchoalveolar lavage fluid revealed positive culture results (7/10) but variable colony counts, neutrophil percentages, and concentrations of interleukin-8 and interleukin-1 beta equally in both CF genotype groups. These markers of pulmonary inflammation were not correlated, individually or collectively, with REE or genotype. We conclude that genotypic variations in energy balance are detectable early in CF unrelated to lung inflammation. Subclinical defects in body composition and pulmonary integrity occur early in CF and, in combination with increased cellular metabolic activity, have important clinical implications with respect to early diagnosis and management.
The goal of this study was to evaluate the safety and efficacy of recombinant human DNase (rhDNase) in hospitalized patients with cystic fibrosis (CF) experiencing acute pulmonary exacerbations. Eighty patients with documented CF were enrolled at 11 CF centers when admitted for antibiotic therapy. Patients were at least 5 yr old with a forced vital capacity (FVC) > or = 35% of predicted and an oxygen saturation > or = 90% on a fraction of inspired oxygen (FIO2) < 0.5. Patients were randomized to receive rhDNase 2.5 mg in 2.5 ml excipient twice a day (n = 43) or 2.5 ml excipient alone twice daily (n = 37) along with conventional treatment for exacerbations. Administration of rhDNase was not associated with acute adverse events or deaths, and no patients experienced allergic or anaphylactic reactions. Although forced expiratory volume in one second (FEV1) and FVC improved in both treatment groups during the double-blind period, there were no statistically significant differences in the mean change from baseline in FEV1 or FVC between the two groups. rhDNase therapy is safe and well tolerated in CF patients with acute exacerbations requiring hospitalization, but the study did not demonstrate a statistically significant therapeutic effect of rhDNase when added to a regimen of antibiotics and chest physical therapy.
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Earlier studies have reported the presence of interleukin-1 (IL-1) and tumor necrosis factor (TNF) in the plasma of patients with cystic fibrosis (CF), but the results have been inconsistent. To investigate the relationships among plasma IL-1 alpha, IL-1 beta, TNF, lipopolysaccharide (LPS), and clinical status, measurements were made before and after 14 days of intravenous antibiotic therapy in 13 patients with CF. In addition, whole blood cytokine production rates were measured in 18 hr cultures stimulated with 10 micrograms/mL LPS or sterile saline (control). On admission, patients with CF had significantly greater plasma levels of LPS and IL-1 alpha compared with 20 healthy adult controls. In response to antibiotic therapy, the patients had statistically significant increases in weight, oxygen saturation, chest radiograph score, and forced expiratory volume in 1 second. They had significant decreases in pulse rate, residual volume/total lung capacity ratio, white blood count, neutrophil count, LPS concentration, and resting energy expenditure per kg body weight. There were no significant changes in the plasma concentrations of IL-1 alpha, IL-1 beta, or TNF and no significant changes in the basal or stimulated whole blood production rates of IL-1 alpha, IL-1 beta, or TNF. The immunological variables did not correlate significantly with clinical measurements of severity or the presence of fever. It is likely that in CF local pulmonary effects of cytokines are of more pathophysiologic significance than systemic effects.
Cystic fibrosis is a serious, common genetic condition that causes recurrent pulmonary infections, malabsorption, and increased sweat electrolytes. Despite significant improvements in clinical treatment, individuals continue to die from progressive, obstructive pulmonary disease as children and young adults. This article reviews the current status of our understanding of cystic fibrosis: the basic defect, animal models, current therapy, and new approaches to the pulmonary disease.
Pulmonary embolism is an uncommon diagnosis in the pediatric patient, often discovered on autopsy. The mortality rate of untreated pulmonary embolism approaches 30%, and the best way to prevent death is by swift diagnosis and initiation of therapy. This article reviews the risk factors, clinical presentation, pathophysiology, diagnostic modalities, and treatment of pulmonary embolism in children.
Cystic fibrosis (CF) is a common, fatal hereditary disease resulting from mutations of the human cystic fibrosis transmembrane conductance regulator (CFTR) gene in which epithelial cells throughout the body manifest altered regulation of apical membrane chloride secretion. Although the disease affects multiple organs throughout the body, over 90% of patients die of complications of the lung involvement. The feasibility of adenovirus-derived vectors for in vivo delivery of the human CFTR cDNA to treat the pulmonary component of CF is currently being evaluated using in vitro and in vivo approaches. Defining the therapeutic window between biological efficacy and toxicity is an important part of this work. Here we present data regarding the preclinical evaluation of the safety of in vivo delivery of the human CFTR cDNA to the cotton rat airway epithelium using the replication-deficient adenoviral vector Av1Cf2 or a similar vector, Av1LacZ4, expressing the Escherichia coli LacZ gene as a histologic marker. Gene transfer to the respiratory epithelium was efficient, as demonstrated by in situ hybridization and histochemical staining. Administration of these vectors resulted in a mild, transient, dose-dependent cellular inflammatory response similar in character to that seen with adenovirus 5 (Ad5), but far less in intensity, which was not associated with structural lung damage or mortality. Av1Cf2 DNA sequences were easily detected in the lung after pulmonary administration, but could not be demonstrated in organs other than the lung. These preclinical observations suggest that adenovirus-mediated gene transfer to the airway epithelium can be achieved efficiently, but is accompanied by a dose- and time-dependent inflammation.(ABSTRACT TRUNCATED AT 250 WORDS)
As most of the morbidity seen in cystic fibrosis (CF) is related to pulmonary complications, new therapies are being developed that seek to ameliorate these debilitating sequelae. Recently, there has been intense effort into the development of new aerosol-based therapies for CF. This review summarizes much of this recent investigation, with particular emphasis on therapies described in the literature within the past year. Agents that act on the airway epithelium to alter ionic fluxes, namely amiloride and uridine 5'-triphosphate, are outlined. The effects of tobramycin delivered via nebulizer in a cohort of stable CF patients is reported. Recombinant human DNase and distearoyl phosphatidylglycerol liposomes, agents that alter the adhesiveness of CF mucus, are outlined as possible strategies for CF treatment. Finally, antiprotease therapy is considered as a possible addition to the CF armamentarium.
This study was undertaken to evaluate in a primarily pediatric population whether the late effects of bone marrow transplantation (BMT) on pulmonary function in patients having undergone the procedure for treatment of acute leukemia or lymphoma are worse than that of patients having undergone transplant for treatment of aplastic anemia. Forty-six patients were studied. We did not demonstrate statistically significant differences in group mean forced expiratory flow in one second/forced vital capacity (FEV1/FVC) and percentage predicted forced expiratory volume in one second (FEV1), forced vital capacity (FVC), forced expiratory flow at 25-75% of the forced vital capacity (FEF25-75) and total lung capacity (TLC) values between the two groups of patients before BMT and to 7 years post-transplant. Individual patients with pulmonary function abnormalities were identified. Furthermore, there were no significant differences between the two study groups or within the group of patients with aplastic anemia from pre-transplant to 9-12 months and from pre-transplant to 18-24 months after BMT. However, within the group of patients treated for acute leukemia or lymphoma, there was a significant decline in the group mean percentage predicted FVC (p = 0.0001), FEV1 (p = 0.0006) and FEF25-75 (p = 0.0063) from pre-transplant to 9-12 months and in the FVC (p = 0.004) and FEV1 (p = 0.0006) from pre-transplant to 18-24 months after BMT. The greater decline in the FVC relative to the FEV1 suggests the development of a restrictive process in this group of patients.
BACKGROUND: Direct aerosol delivery of aminoglycosides such as tobramycin to the lower airways of patients with cystic fibrosis may control infection with Pseudomonas aeruginosa and improve pulmonary function, with low systemic toxicity. We conducted a randomized crossover study to evaluate the safety and efficacy of aerosolized tobramycin in patients with cystic fibrosis and P. aeruginosa infections. METHODS: Seventy-one patients with stable pulmonary status were recruited from seven U.S. centers for the treatment of cystic fibrosis and randomly assigned to one of two crossover regimens. Group 1 received 600 mg of aerosolized tobramycin for 28 days, followed by half-strength physiologic saline (placebo) for two 28-day period. Group 2 received placebo for 28 days, followed by tobramycin for two 28-day periods. Pulmonary function, the density of P. aeruginosa in sputum, ototoxicity, nephrotoxicity, and the emergence of tobramycin-resistant P. aeruginosa were monitored. RESULTS: In the first 28-day period, treatment with tobramycin was associated with an increase in the percentage of the value predicted for forced expiratory volume in one second (9.7 percentage points higher than the value for placebo; P < 0.001), forced vital capacity (6.2 percentage points higher than the value for placebo; P = 0.014), and forced expiratory flow at the midportion of the vital capacity (13.0 percentage points higher than the value for placebo; P < 0.001). A decrease in the density of P. aeruginosa in sputum by a factor of 100 (P < 0.001) was found during all periods of tobramycin administration. Neither ototoxicity nor nephrotoxicity was detected. The frequency of the emergence of tobramycin-resistant bacteria was similar during both tobramycin and placebo administration. CONCLUSIONS: The short-term aerosol administration of a high dose of tobramycin in patients with clinically stable cystic fibrosis is an efficacious and safe treatment for endobronchial infection with P. aeruginosa.
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Pulmonary complications are a major cause of morbidity and mortality in bone marrow transplant recipients. Earlier series, consisting mainly of adults, have shown evidence of obstructive changes of pulmonary functions in association with chronic graft-versus-host disease (CGVHD). We longitudinally evaluated spirometry in 46 patients who received bone marrow transplants as children or as young adults to determine whether they had similar abnormalities. Group mean FEV1/FVC, and percent predicted FVC, FEV1, and FEF25-75 values did not demonstrate obstructive changes in association with CGVHD in this patient population. Our findings suggest that younger patients with CGVHD, as a group, may fare better than older bone marrow transplant recipients with CGVHD. However, due to small sample sizes, it cannot be conclusively stated that the pulmonary function parameters analyzed do not differ in the two patient groups.
Lung diffusing capacity was measured in 92 healthy Caucasian children (52 boys and 40 girls), ranging in age from 6 to 17 years, using the single breath carbon monoxide technique (DLCO). Multiple regression equations were developed to predict the DLCO value. Standing height, gender, weight, and age were significant factors in the prediction of DLCO. Sitting height was not a significant covariate when standing height was in the model, but it could replace standing height in the equation. Equations are presented for the calculation of predicted DLCO in children based on standing or sitting height, age, sex, and weight.
To investigate its role in pulmonary infections, concentrations of interleukin-1 were measured in 22 bronchoalveolar lavage fluid (BALF) samples from 19 children with cystic fibrosis (CF), and in 13 disease controls by enzyme-linked immunosorbent assay (ELISA) for IL-1 beta and the D10.G4.1 proliferation assay for IL-1 activity. Significantly higher levels of IL-1 beta and IL-1 activity were found in BALF from patients with bacterial pulmonary infections than in those without such infection. There was no significant difference between the levels in patients with CF and pulmonary infections and those in children with bacterial infections complicating other diseases. High performance liquid chromatography showed that most of the IL-1 beta was associated with a molecular weight peak of 17 to 18 kD. Pulmonary inflammation reflected by the number of polymorphonuclear leukocytes (PMN) in the sample correlated significantly with the IL-1 concentration.