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Biomedical subjects

A Catanzaro

Publications and source records attributed to A Catanzaro.

At least 19 recordsLinked to original sources

Immunological characterization of novel secreted antigens of Mycobacterium tuberculosis.

Proteins secreted by Mycobacterium tuberculosis are targets of host immune responses and as such are investigated for vaccine and immunodiagnostics development. Computer-driven searches of the M. tuberculosis H37Rv genome had previously identified 45 novel secreted proteins. Here, we report the characterization of these antigens in terms of specificity for the M. tuberculosis complex and the ability to induce human immune responses. BLAST homology searches and Southern hybridization identified 10 genes that were either specific for the M. tuberculosis complex or found in only two nontuberculous mycobacterial species of minor medical significance. Selected recombinant proteins were purified from Escherichia coli cells and tested for the ability to elicit antibody responses in tuberculosis patients. Reactivity of the serum panel was ' 36% with at least one of five novel proteins (Rv0203, Rv0603, Rv1271c, Rv1804c and Rv2253), 56% with the 38 kDa lipoprotein, a M. tuberculosis antigen known to be highly seroreactive, and 68% with a combination of Rv0203, Rv1271c and the 38 kDa antigen. Thus, at least five novel secreted proteins induce antibody responses during active disease; some of these proteins may increase the sensitivity of serological assays based on the 38 kDa antigen.

Antibodies, Bacterial↗

Integration of microscopy and serodiagnostic tests to screen for active tuberculosis.

SETTING: University of California San Diego Medical Center, USA. OBJECTIVE: To create a simple screening strategy for tuberculosis (TB) that includes antibody detection assays to improve the accuracy of microscopic examination of sputum for acid-fast bacilli (AFB smear). METHODS: Serum samples were obtained from 190 patients suspected of having active TB. TB diagnosis was established by Mycobacterium tuberculosis culture. HIV status was determined by commercial serologic tests. IgG antibody levels were measured by ELISA using purified M. tuberculosis antigens. Data from 130 randomly selected patients were used to develop a screening strategy; data from the remaining 60 patients were used for validation. RESULTS: AFB smear had 70% sensitivity and 88% specificity. In algorithms integrating single or multi-antigen ELISA with AFB smear and HIV results, the sensitivity improved over each test alone. The algorithm that included a four-antigen ELISA (38 kDa antigen, lipoarabinomannan, MPT-64 and glutamine synthase) had a sensitivity of 93% and a specificity of 76%. Compared to AFB smear, the sensitivity of the algorithm was significantly higher, while the specificity was not statistically different. CONCLUSION: This study demonstrates that a screening strategy can be created by integrating multi-antigen ELISA with AFB smear and HIV testing.

Adult↗

Enhancement of innate immunity against Mycobacterium avium infection by immunostimulatory DNA is mediated by indoleamine 2,3-dioxygenase.

Bacterial DNA and its synthetic immunostimulatory oligodeoxynucleotide analogs (ISS-ODN) activate innate immunity and promote Th1 and cytotoxic T-lymphocyte immune responses. Based on these activities, we investigated whether ISS-ODN could modify the course of Mycobacterium avium infection. M. avium growth in vitro was significantly inhibited by ISS-ODN treatment of human and mouse macrophages, and M. avium growth in vivo was similarly inhibited in C57BL/6 mice treated with ISS-ODN. This protective effect of ISS-ODN was largely independent of tumor necrosis factor alpha (TNF-alpha), interleukin 12 (IL-12), nitric oxide, NADPH oxidase, alpha/beta interferon (IFN-alpha/beta), and IFN-gamma. In contrast, we found that the induction of indoleamine 2,3-dioxygenase (IDO) was required for the antimycobacterial effect of ISS-ODN. To evaluate the potential for synergism between ISS-ODN and other antimycobacterial agents, treatment with a combination of ISS-ODN and clarithromycin (CLA) was tested in vitro and in vivo. ISS-ODN significantly enhanced the therapeutic effect of CLA in both human and mouse macrophages and in C57BL/6 mice. This study newly identifies IDO as being involved in the antimicrobial activity of ISS-ODN and suggests the usefulness of ISS-ODN when used in combination with conventional chemotherapy for microbial infections.

Adjuvants, Immunologic↗

Management of tuberculosis in San Diego County: a survey of physicians' knowledge, attitudes and practices.

SETTING: A survey conducted in San Diego County. OBJECTIVE: To assess local physicians' knowledge, attitudes and practices regarding tuberculosis (TB). METHODS: The survey consisted of questions covering diagnosis and treatment of active disease, diagnosis and treatment of latent infection, and infection control. The survey was sent to physicians who reported a TB case or suspect to the local health department in the years 1995-1997. RESULTS: Of the 384 physicians in this group, 150 (39%) returned the survey form. The percentage of physicians whose response conformed to health department guidelines varied widely from question to question (51%-94%, median 83%). Pulmonary medicine and infectious diseases specialists, physicians educated completely in the United States (US), and physicians who treated six or more TB patients in the past 2 years were more likely to give answers in agreement with health department policies. CONCLUSIONS: Because the response rate to the survey was low, these findings may not be completely representative of the targeted group of physicians. Nevertheless, they may indicate that health care provider education about TB management standards is needed.

California↗

Comparison of oral fluconazole and itraconazole for progressive, nonmeningeal coccidioidomycosis. A randomized, double-blind trial. Mycoses Study Group.

BACKGROUND: In previous open-label noncomparative clinical trials, both fluconazole and itraconazole were effective therapy for progressive forms of coccidioidomycosis. OBJECTIVE: To determine whether fluconazole or itraconazole is superior for treatment of nonmeningeal progressive coccidioidal infections. DESIGN: Randomized, double-blind, placebo-controlled trial. SETTING: 7 treatment centers in California, Arizona, and Texas. PATIENTS: 198 patients with chronic pulmonary, soft tissue, or skeletal coccidioidal infections. INTERVENTION: Oral fluconazole, 400 mg/d, or itraconazole, 200 mg twice daily. MEASUREMENTS: After 4, 8, and 12 months, a predefined scoring system was used to assess severity of infection. Findings were compared with those at baseline. RESULTS: Overall, 50% of patients (47 of 94) and 63% of patients (61 of 97) responded to 8 months of treatment with fluconazole and itraconazole, respectively (difference, 13 percentage points [95% CI, -2 to 28 percentage points]; P = 0.08). Patients with skeletal infections responded twice as frequently to itraconazole as to fluconazole. By 12 months, 57% of patients had responded to fluconazole and 72% had responded to itraconazole (difference, 15 percentage points [CI, 0.003 to 30 percentage points]; P = 0.05). Soft tissue disease was associated with increased likelihood of response, as in previous studies. Azole drug was detected in serum specimens from all but 3 patients; however, drug concentrations were not helpful in predicting outcome. Relapse rates after discontinuation of therapy did not differ significantly between groups (28% after fluconazole treatment and 18% after itraconazole treatment). Both drugs were well tolerated. CONCLUSIONS: Neither fluconazole nor itraconazole showed statistically superior efficacy in nonmeningeal coccidioidomycosis, although there is a trend toward slightly greater efficacy with itraconazole at the doses studied.

Administration, Oral↗

Practice guideline for the treatment of coccidioidomycosis. Infectious Diseases Society of America.

Management of patients diagnosed with coccidioidomycosis involves defining the extent of infection and assessing host factors that predispose to disease severity. Patients with relatively localized acute pulmonary infections and no risk factors for complications often require only periodic reassessment to demonstrate resolution of their self-limited process. On the other hand, patients with extensive spread of infection or at high risk of complications because of immunosuppression or other preexisting factors require a variety of treatment strategies that may include antifungal therapy, surgical debridement, or both. Amphotericin B is often selected for treatment of patients with respiratory failure due to Coccidioides immitis or rapidly progressive coccidioidal infections. With other more chronic manifestations of coccidioidomycosis, treatment with fluconazole, itraconazole, or ketoconazole is common. Duration of therapy often ranges from many months to years, and, for some patients, chronic suppressive therapy is needed to prevent relapses.

Antifungal Agents↗

A randomized trial of itraconazole in allergic bronchopulmonary aspergillosis.

BACKGROUND: Allergic bronchopulmonary aspergillosis is a hypersensitivity disorder that can progress from an acute phase to chronic disease. The main treatment is systemic corticosteroids, but data from uncontrolled studies suggest that itraconazole, an orally administered antifungal agent, may be an effective adjunctive therapy. METHODS: We conducted a randomized, double-blind trial of treatment with either 200 mg of itraconazole twice daily or placebo for 16 weeks in patients who met immunologic and pulmonary-function criteria for corticosteroid-dependent allergic bronchopulmonary aspergillosis. A response was defined as a reduction of at least 50 percent in the corticosteroid dose, a decrease of at least 25 percent in the serum IgE concentration, and one of the following: an improvement of at least 25 percent in exercise tolerance or pulmonary-function tests or resolution or absence of pulmonary infiltrates. In a second, open-label part of the trial, all the patients received 200 mg of itraconazole per day for 16 weeks. RESULTS: There were responses in 13 of 28 patients in the itraconazole group (46 percent), as compared with 5 of 27 patients in the placebo group (19 percent, P=0.04). The rate of adverse events was similar in the two groups. In the subsequent open-label phase, 12 of the 33 patients who had not had a response during the double-blind phase (36 percent) had responses, and none of the patients who had a response in the double-blind phase of the trial had a relapse. CONCLUSIONS: For patients with corticosteroid-dependent allergic bronchopulmonary aspergillosis, the addition of itraconazole can lead to improvement in the condition without added toxicity.

Adrenal Cortex Hormones↗

The role of clinical suspicion in evaluating a new diagnostic test for active tuberculosis: results of a multicenter prospective trial.

CONTEXT: In laboratory trials, nucleic acid amplification tests for the diagnosis of tuberculosis (TB) are more accurate than acid-fast bacilli (AFB) smear microscopy and are faster than culture. The impact of these tests on clinical diagnosis is not known. OBJECTIVE: To assess the performance of a nucleic acid amplification test, the enhanced Mycobacterium tuberculosis Direct (E-MTD) test, against a uniform clinical standard stratified by level of clinical suspicion. DESIGN: Prospective multicenter trial conducted between February and December 1996, documenting the clinical suspicion of TB at enrollment and using final comprehensive diagnosis as the criterion standard. SETTING: Six urban medical centers and 1 public health TB clinic. PATIENTS: A total of 338 patients with symptoms and signs consistent with active pulmonary TB and complete clinical diagnosis were stratified by the clinical investigators to be at low (< or =25%), intermediate (26%-75%), or high (>75%) relative risk of having TB. MAIN OUTCOME MEASURES: Sensitivity, specificity, and positive and negative predictive values of the E-MTD test in clinical suspicion of groups with low (n = 224); intermediate (n = 68); and high (n = 46) clinical suspicion of TB. RESULTS: Based on comprehensive clinical diagnosis, sensitivity of the E-MTD test was 83%, 75%, and 87% for low, intermediate, and high clinical suspicion of TB, respectively, and corresponding specificity was 97%, 100%, and 100% (P = .25). Positive predictive value of the E-MTD test was 59% (low), 100% (intermediate), and 100% (high) compared with 36% (low), 30% (intermediate), and 94% (high) for AFB smear. Corresponding negative predictive values were 99%, 91%, and 55% [corrected] (E-MTD test) vs 96%, 71%, and 37% (AFB smear). CONCLUSIONS: For complex diagnostic problems like TB, clinical risk assessments can provide important information regarding predictive values more likely to be experienced in clinical practice. For this series, a clinical suspicion of TB was helpful in targeting areas of the clinical spectrum in which nucleic acid amplification tests can make an important contribution.

Adult↗

Release of monocyte chemoattractant protein (MCP)-1 by a human alveolar epithelial cell line in response to mycobacterium avium.

Clinical strains of Mycobacterium avium isolated from patients with acquired immunodeficiency syndrome, but not a non-clinical laboratory strain (ATCC 25291), were found to stimulate the human alveolar epithelial cell line A549, to produce monocyte chemoattractant protein (MCP)-1. A549 cells were also found to produce elevated levels of MCP-1 in response to sonicates of the clinical strains of M. avium, and surprisingly, the non-clinical strain as well. However, sonic extracts of the clinical strains were found to induce significantly higher levels of MCP-1 production compared to extracts of the non-clinical strain (P < 0.001). These data suggest the existence of strain-related differences in antigen expression by M. avium. The clinical and non-clinical strains of M. avium were found to attach and invade, but not replicate in A549 cells indicating that MCP-1 production by A549 cells does require the presence of viable, replicating organisms. Activation of alveolar epithelial cells by exposure to M. avium resulting in the production of chemokines which recruit inflammatory cells to the site of infection may be an important regulatory pathway for the activation of pulmonary host defense.

Chemokine CCL2↗

Comparison testing of current (PPD-S1) and proposed (PPD-S2) reference tuberculin standards.

Since 1951, the tuberculin PPD-S1 has been used to standardize commercial PPD reagents and perform special tuberculin surveys. PPD-S1 is now in short supply and a new standard (PPD-S2) has been manufactured. To determine if PPD-S2 is equivalent and can replace PPD-S1, we conducted a double-blind clinical trial. Between May 14 and October 28, 1997, 69 subjects with a history of culture-proven tuberculosis (TB patients) and 1,189 subjects with a very low risk for TB infection were enrolled, received four skin tests (with PPD-S1, PPD-S2, and one each of the commercially available PPDs), and had reactions measured by two trained observers. Among the TB patients, we found statistically indistinguishable immunogenicity (mean reaction size +/- standard deviation): 15.6 +/- 6.6 mm for PPD-S1 and 14.8 +/- 5.6 mm for PPD-S2. Among low-risk subjects, the tests had equally high specificities (PPD-S1, 98.7% and PPD-S2, 98. 5%), using a 10-mm cutoff. The number of discordant (negative versus positive) interpretations for PPD-S2, assuming that low-risk subjects who had a >/= 10 mm reaction to PPD-S1 were truly infected, was low (0.5%) and indistinguishable from the rate of discordant interpretations of the same test when read by two different observers (0.8%). The study results indicate that PPD-S2 is qualified to be used as the new U.S. reference standard for PPD tuberculin.

Adult↗

Comparable specificity of 2 commercial tuberculin reagents in persons at low risk for tuberculous infection.

CONTEXT: One or both commercial tuberculin skin test reagents (Aplisol and Tubersol) may have a high rate of false-positive reactions. OBJECTIVE: To compare the reaction size and specificity of skin testing with Aplisol, Tubersol, and the standard purified protein derivative (PPD-S1). DESIGN: Double-blind trial, conducted between May 14, 1997, and October28, 1997, in which each individual received 4 tuberculin skin reagents at sites assigned at random. SETTING: Health departments and universities in 6 US cities. PARTICIPANTS: A total of 1555 persons at low risk of latent tuberculosis infection. INTERVENTION: Simultaneous skin tests with Aplisol, Tubersol, PPD-S1, and either a second PPD-S1 or PPD-S2 (a proposed new standard). MAIN OUTCOME MEASURE: Reaction size at each injection site measured by 2 investigators blinded to type of reagent. RESULTS: Aplisol produced slightly larger reactions than Tubersol, but this difference did not significantly change skin test interpretation. The mean +/- SD reaction sizes were 3.4+/-4.2 mm with Aplisol, 2.1+/-3.2 mm with Tubersol, and 2.5+/-3.6 mm with PPD-S1. Assuming that all participants were uninfected and using a 10-mm cutoff, the specificities of the tests were high: Aplisol, 98.2%; Tubersol, 99.2%; and PPD-S1, 98.9%. Significant variability was not detected in interobserver, host, and lot-to-lot reagent comparisons. CONCLUSION: Using a cutoff of at least 10 mm, testing with 3 different PPD reagents resulted in similar numbers of uninfected persons being correctly classified.

Adult↗

Healthcare worker compliance with nosocomial tuberculosis control policies.

To determine compliance with nosocomial tuberculosis control measures, 541 healthcare worker observations were made for 52 patients placed in respiratory isolation. Sixty-four total violations were noted, of which 45% occurred in physicians in training. Overall compliance with tuberculosis control measures appeared to be good, but additional educational efforts are warranted.

California↗

Airway coccidioidomycosis--report of cases and review.

Infection due to Coccidioides immitis usually begins in the lungs. Despite the initial pulmonary portal of entry, endotracheal and endobronchial coccidioidomycosis has rarely been described. Since the introduction of fiberoptic bronchoscopy and the AIDS epidemic, more C. immitis lesions of the large airways have been noted. We present data on 38 cases of coccidioidomycosis of the airways, including 6 cases detailed from our own experience and 32 from the literature. Direct infection of the airways (28 cases) is a more common mechanism of airways disease than is erosion into the airways from a lymph node (5 cases). Bronchoscopic findings vary and may show mucosal involvement or intrinsic obstruction. Endotracheal and endobronchial disease is not a self-limited disease and requires antifungal therapy. Disseminated disease in these patients is common. Coccidioidomycosis must be considered in the differential diagnosis of airway pathology.

Adult↗

Costs associated with tuberculosis control programs at hospitals caring for children.

OBJECTIVE: No data are available on the costs of implementing infection control measures for the control of Mycobacterium tuberculosis (MTB) in pediatric settings. In this study we determined the cost of MTB control measures at three hospitals caring for children. DESIGN: Infection control and tuberculosis (TB) coordinators obtained cost data retrospectively for the years 1994 to 1995 for tuberculin skin test programs, respiratory protection programs and the retrofit or new construction of environmental controls in pediatric settings. SETTING: Two pediatric hospitals and one pediatric ward in a large tertiary care hospital. RESULTS: Total expenditures for TB controls ranged from $15270 to $28158 for the 2-year study period. Engineering controls involved the largest capital outlay at two of three facilities. Average yearly tuberculin skin test costs ranged from $949 to $12504/hospital. Respiratory protection programs cost from $480 to $1680 during the 2-year study period. CONCLUSIONS: Costs associated with implementing control measures varied slightly by hospital but were less than those incurred by hospitals caring for adults. These costs represent improvements made to upgrade selected aspects of hospital TB control programs, not the cost of an optimal TB control program. Optimal TB control programs in pediatric settings have yet to be described.

Adolescent↗

Role of CD40 ligand in Mycobacterium avium infection.

Mycobacterium avium is a common opportunistic pathogen in immunocompromised patients such as those infected with human immunodeficiency virus. Although M. avium is an intracellular organism replicating predominantly in macrophages, disseminated M. avium infection is seen in AIDS patients with CD4(+) cell counts of <50 cells/microliters, suggesting a possible involvement of a T cell-macrophage interaction for the elimination of M. avium. To determine whether CD40-CD40 ligand (CD40L) interactions play a role in M. avium infection, we studied the ability of CD40L to restrict M. avium replication in human monocyte-derived macrophages (MDM) in vitro. MDM were infected with M. avium and cocultured with CD40L-transfected 293 cells for 7 days. Intracellular growth of M. avium in these MDM was assessed by colony counting. CD40L-expressing cells inhibited growth of M. avium in MDM by 86.5% +/- 4.2% compared to MDM cultured with control cells. These findings were verified by assays using purified, soluble recombinant human CD40L (CD40LT). CD40LT (5 micrograms/ml) inhibited intracellular growth of M. avium by 76.9% +/- 18.0% compared to cells treated with medium alone. Inhibition by CD40LT was reduced by monoclonal antibodies (MAbs) against CD40 and CD40L. The inhibitory effect of CD40LT was not accompanied by enhancement of interleukin-12 (IL-12) production by M. avium-infected MDM, while CD40L-expressing cells stimulated IL-12 production by these cells. Treatment of M. avium-infected mice with MAb against murine CD40L resulted in recovery of larger numbers of organisms (0.8 to 1.0 log) from the spleens, livers, and lungs of these animals compared to infected mice which received normal immunoglobulin G. These results indicate that CD40-CD40L signaling may be an important step in host immune response against M. avium infection.

Animals↗

Development of housing programs to aid in the treatment of tuberculosis in homeless individuals: a pilot study.

STUDY OBJECTIVES: To describe our experience with novel supervised housing programs developed to aid in the treatment of tuberculosis (TB) in homeless individuals, including a preliminary analysis of their effectiveness and estimate of potential cost savings. DESIGN: Retrospective chart review. SETTING: A county TB control program. METHODS: The San Diego County TB Control Program's computer database was used to identify homeless individuals placed in one of two supervised housing programs for treatment of TB [Young Men's Christian Association (YMCA), for noninfectious patients, or Bissell House, for infectious patients]. Charts for all these patients were reviewed and information regarding their demographics, underlying medical conditions, therapy, microbiologic markers of response to therapy, hospitalizations, and participation in supervised housing programs was recorded. MEASUREMENTS AND RESULTS: The sputum culture conversion and treatment completion rates for those housed in the YMCA were 100 and 84.6%, respectively. Of the patients in the Bissell House program, 100% had converted their smear and culture. In addition, all patients in this program completed an adequate course of supervised therapy. These rates of microbiologic conversion and treatment completion compare favorably with historical data from San Diego County and other locations. Estimated cost savings for placing medically stable infectious patients in the Bissell House for respiratory isolation and supervised treatment were estimated to be $27,034 per patient. CONCLUSIONS: Use of supervised housing to aid in treatment of TB in the homeless appears to be effective and results in substantial cost savings. A larger multicenter study should be considered to confirm these findings and better quantify the cost-effectiveness of such programs.

AIDS-Related Opportunistic Infections↗