Safety and biological efficacy of an adeno-associated virus vector-cystic fibrosis transmembrane regulator (AAV-CFTR) in the cystic fibrosis maxillary sinus.

OBJECTIVE: The host immune response and low vector efficiency have been key impediments to effective cystic fibrosis transmembrane regulator (CFTR) gene transfer for cystic fibrosis (CF). An adeno-associated virus vector (AAV-CFTR) was used in a phase I dose-escalation study to transfer CFTR cDNA into respiratory epithelial cells of the maxillary sinus of 10 CF patients. STUDY DESIGN: A prospective, randomized, unblinded, dose-escalation, within-subjects, phase I clinical trial of AAV-CFTR was conducted. PATIENTS: Ten patients with previous bilateral maxillary antrostomies were treated. MAIN OUTCOME MEASURES: Safety, gene transfer as measured by semiquantitative polymerase chain reaction (PCR), and sinus transepithelial potential difference (TEPD) were measured. RESULTS: The highest level of gene transfer was observed in the range of 0.1-1 AAV-CFTR vector copy per cell in biopsy specimens obtained 2 weeks after treatment. When tested, persistence was observed in one patient for 41 days and in another for 10 weeks. Dose-dependent changes in TEPD responses to pharmacologic intervention were observed following treatments. Little or no inflammatory or immune responses were observed. CONCLUSION: AAV-CFTR administration to the maxillary sinus results in successful, dose-dependent gene transfer to the maxillary sinus and alterations in sinus TEPD suggestive of a functional effect, with little or no cytopathic or host immune response. Further study is warranted for AAV vectors as they may prove useful for CFTR gene transfer and other in vivo gene transfer therapies. A prospective, randomized, double-blind, placebo-controlled, within-subjects, phase II clinical trial of the effect AAV-CFTR on clinical recurrence of sinusitis will determine the clinical efficacy of AAV gene therapy for CF.

Time to resolution of morbidity: an endpoint for assessing the clinical cure of community-acquired pneumonia.

Clinical trials of new therapeutics for community-acquired pneumonia (CAP) have typically used a subjective endpoint of clinical response. However, as this endpoint is not quantitative, it is subject to observer bias and renders the conduct of multicenter trials difficult. For the purposes of conducting a clinical trial of filgrastim, as an adjunct to antibiotics for the treatment of CAP, a set of clinical criteria were developed prospectively to determine the time when a clinical cure was achieved, based on respiratory rate, temperature, oxygenation and roentgenographic findings, which was termed the time to resolution of morbidity (TRM). The TRM was evaluated on the first 100 patients entered in this clinical trial. As no clear reference standard exists, the predictive value for the duration of parenteral antibiotics (AB) and the length of hospital stay (LOS) was compared with that provided by a widely used classification system for severity of disease, APACHE II. The TRM was found to correlate significantly better with AB or LOS than APACHE II (P < 0.001). Furthermore, TRM offers the benefit over the endpoints of LOS and AB of being specifically designed to measure the patient's response to therapy, and, in fact, may aid physicians in determining the duration of parenteral antibiotic therapy. Hence, TRM is relevant to the clinician and is a useful tool to ensure uniformity in the assessment of the response to a new therapeutic in a multicenter clinical trial.

Recombinant methionyl human granulocyte colony-stimulating factor for the prevention and treatment of non-neutropenic infectious diseases.

Recombinant methionyl human granulocyte colony-stimulating factor (r-metHuG-CSF, hereafter G-CSF) has been demonstrated in clinical trials to be effective in correcting iatrogenic neutropenia by stimulating the production of neutrophils. Not surprisingly, G-CSF has also been found to induce neutrophilia in non-neutropenic hosts. Experimental data suggest that G-CSF leads to the enhancement of neutrophil function. Endogenous G-CSF levels are elevated over a broad spectrum of serious infectious diseases, suggesting the clinical importance of G-CSF in these settings. These findings have stimulated research on the use of G-CSF alone or as an adjunct to conventional antimicrobial therapy in a number of non-neutropenic animal models of infections. In total these studies suggest that G-CSF may be useful in the prevention or therapy of infections in both non-neutropenic and neutropenic clinical settings.

Pilot study of anti-lipopolysaccharide human monoclonal antibody MAB-T88 in patients with gram-negative sepsis.

MAB-T88 is a human monoclonal IgM antibody directed at the lipopolysaccharide of gram-negative bacteria. A protocol was designed to identify a group of septic patients with a very high likelihood of gram-negative bacteremia. All 6 patients entered in the protocol had a gram-negative source, and 4 of 6 had gram-negative bacteremia. In this patient population, MAB-T88 was shown to be safe with an effective half-life of 19.1 hours.

Phase I study of antilipopolysaccharide human monoclonal antibody MAB-T88.

Monoclonal antibody MAB-T88 is a human monoclonal immunoglobulin M antibody directed at the lipopolysaccharide of gram-negative bacteria. In this study, nine patients who were expected to become neutropenic from antineoplastic chemotherapy received an infusion of MAB-T88, three patients at each of three doses: 1, 4, and 8 mg/kg of body weight. MAB-T88 was shown to be safe, with an effective half-life in plasma of 25.4 h, and no patient developed immunoglobulin G antibody to MAB-T88.

Tn1725 transposon mutagenesis of 9-18 delta 7, an EcoRI deletion derivative of Salmonella dublin lane plasmid pSDL2.

A 37.5-kb derivative of the Salmonella dublin virulence plasmid pSDL2 was subjected to mutagenesis with the transposon Tn1725. Fifty-two insertions were mapped, and the mutants were tested for their ability to restore virulence to a plasmid-free strain of S. dublin. Twenty-nine of these inserts could not restore full virulence and thus define nine regions of the plasmid essential for virulence. Deletion of a 4.5-kb region by Bal31 nuclease resulted in a 33-kb derivative that maintained full virulence.

Bacterial adherence to bladder uroepithelial cells in catheter-associated urinary tract infection.

To assess the role of bacterial adherence to uroepithelial cells in the pathogenesis of nosocomial urinary tract infection, we prospectively studied 55 patients with indwelling urinary catheters. We obtained uroepithelial cells from the bladder and urine for culture on the patients' entry into the study and every two to four days during catheterization. In all, 235 collections of uroepithelial cells from these patients were used in an in vitro adherence assay with six gram-negative bacterial strains. With uroepithelial cells from patients who did not have bacterial infections, the adherence of the bacteria used in the assay differed significantly according to species. The least adherence occurred with Escherichia coli GR12; the adherence increased with (in order) Proteus mirabilis, E. coli J96, Klebsiella pneumoniae, Serratia marcescens, and Pseudomonas aeruginosa. With cells collected just before the onset of bacteriuria, adherence of these gram-negative strains was higher in patients in whom gram-negative rod infections developed than in those with gram-positive coccal infections (P = 0.005). Analysis with the Cox proportional-hazards model demonstrated that a significant increase in bacterial adherence to uroepithelial cells in the bladder occurred two to four days before the onset of bacteriuria, but that adherence returned to base-line values with the onset of bacteriuria. These results suggest that a transient increase in the adherence of gram-negative bacteria to bladder epithelial cells may be an important early event in the development of catheter-associated bacteriuria.

Urinary-tract infection in sexually active homosexual men.

14 of 280 young, sexually active men with acute urinary symptoms had pronounced bacteriuria--13 with Escherichia coli and 1 with Staphylococcus saprophyticus. 12 of the 14 bacteriuric men were homosexual or bisexual, compared with 3 of 22 non-bacteriuric control patients. Pyuria and symptoms of cystitis were more common in the bacteriuric men, and these men frequently had a urethral discharge on examination, and non-gonococcal urethritis on gram stain of the discharge. The E coli strains causing cystourethritis in these men showed properties previously associated with acute-urinary-tract infection in women, including O serotype, haemolysin production, mannose-resistant haemagglutination of human erythrocytes, and P-fimbriation. Sexually active homosexual men are a newly identified group at increased risk of acute urinary-tract infection, and E coli may contribute to non-gonococcal urethritis in this population.

Association of rectal and urethral colonization with urinary tract infection in patients with indwelling catheters.

To assess the role of antecedent rectal and urethral colonization in the pathogenesis of catheter-associated urinary tract infections, we prospectively studied 64 patients, obtaining urine, rectal, and urethral cultures on study entry, two days later, and every four days thereafter. Of 55 patients who remained catheterized for at least three days, urethral colonization with the same microorganism present in bladder urine was observed in the sampling period preceding the onset of bacteriuria in 12 of 18 infections in women and five of 17 in men. Rectal colonization with the infecting strain preceded bacteriuria in 14 of 18 infections in women and five of 17 in men. The identity of the urinary, urethral, and rectal isolates was confirmed by speciation, serotyping, antibiograms, and biotyping. We conclude that rectal and periurethral colonization often precedes catheter-associated bacteriuria, especially in women, and that effective preventive measures aimed at transurethral infection should be developed.

Correlates of homosexual behavior and the incidence of anal cancer.

To determine whether characteristics that are correlated with male homosexual behavior are associated with the incidence of cancer, the names of persons with a diagnosis of cancer in western Washington during 1974 to 1979 were linked to those in the state syphlis registry. Eight of 47 men with anal cancer were found to have had a reactive FTA test result; the expected number, based on the proportion of reactive cases among men with other sites of cancer, was only 0.40. Among men with anal cancer identified through ten population-based cancer-reporting systems in the United States, 24.4% had never been married, compared with 7.8% of men with colon and rectal cancer. Neither of these relationships was observed for women with anal cancer. Because in men, but not in women, having had syphilis and being single are associated with the practice of anal intercourse, our data suggest that anal intercourse may be a risk factor for anal cancer.