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Yehia BR, Mehta JM, Ciuffetelli D, Moore RD, Pham PA, Metlay JP, Gebo KA. Reply to Holtzman and Gallagher. Clin Infect Dis 2012. [DOI: 10.1093/cid/cis724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Downes KJ, Metlay JP, Bell LM, McGowan KL, Elliott MR, Shah SS. Polymicrobial Bloodstream Infections among Children and Adolescents with Central Venous Catheters Evaluated in Ambulatory Care. Clin Infect Dis 2008; 46:387-94. [DOI: 10.1086/525265] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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Metlay JP. Randomized Trial of a Multidimensional Educational Intervention to Improve Antibiotic Use for Adults with Acute Respiratory Infections Managed in the Emergency Department. Acad Emerg Med 2006. [DOI: 10.1197/j.aem.2006.03.136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Finkelstein JA, Davis RL, Dowell SF, Metlay JP, Soumerai SB, Rifas-Shiman SL, Higham M, Miller Z, Miroshnik I, Pedan A, Platt R. Reducing antibiotic use in children: a randomized trial in 12 practices. Pediatrics 2001; 108:1-7. [PMID: 11433046 DOI: 10.1542/peds.108.1.1] [Citation(s) in RCA: 220] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE To test whether an educational outreach intervention for families and physicians, based on the Centers for Disease Control and Prevention (CDC) principles of judicious antibiotic use, decreases antimicrobial drug prescribing for children younger than 6 years old. Setting. Twelve practices affiliated with 2 managed care organizations (MCOs) in eastern Massachusetts and northwest Washington State. Patients. All enrolled children younger than 6 years old. METHODS Practices stratified by MCO and size were randomized to intervention or control groups. The intervention included 2 meetings of the practice with a physician peer leader, using CDC-endorsed summaries of judicious prescribing recommendations; feedback on previous prescribing rates were also provided. Parents were mailed a CDC brochure on antibiotic use, and supporting materials were displayed in waiting rooms. Automated enrollment, ambulatory visit, and pharmacy claims were used to determine rates of antibiotic courses dispensed (antibiotics/person-year) during baseline (1996-1997) and intervention (1997-1998) years. The primary analysis (for children 3 to <36 months and 36 to <72 months) assessed the impact of the intervention among children during the intervention year, controlling for covariates including patient age and baseline prescription rate. Confirmatory analyses at the practice level were also performed. RESULTS The practices cared for 14 468 and 13 460 children in the 2 study years, respectively; 8815 children contributed data in both years. Sixty-two percent of antibiotic courses were dispensed for otitis media, 6.5% for pharyngitis, 6.3% for sinusitis, and 9.2% for colds and bronchitis. Antibiotic dispensing for children 3 to <36 months old decreased 0.41 antibiotics per person-year (18.6%) in intervention compared with 0.33 (11.5%) in control practices. Among children 36 to <72 months old, the rate decreased by 0.21 antibiotics per person-year (15%) in intervention and 0.17 (9.8%) in control practices. Multivariate analysis showed an adjusted intervention effect of 16% in the younger and 12% in the older age groups. The direction and approximate magnitude of effect were confirmed in practice-level analyses. CONCLUSIONS A limited simultaneous educational outreach intervention for parents and providers reduced antibiotic use among children in primary care practices, even in the setting of substantial secular trends toward decreased prescribing. Future efforts to promote judicious prescribing should continue to build on growing public awareness of antibiotic overuse.
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Affiliation(s)
- J A Finkelstein
- Department of Ambulatory Care and Prevention, Harvard Medical School, Boston, Massachusetts, USA.
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Finkelstein JA, Metlay JP, Davis RL, Rifas-Shiman SL, Dowell SF, Platt R. Antimicrobial use in defined populations of infants and young children. Arch Pediatr Adolesc Med 2000; 154:395-400. [PMID: 10768680 DOI: 10.1001/archpedi.154.4.395] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND Antimicrobial overprescribing contributes to bacterial resistance, but data on use in infants and young children are limited. OBJECTIVES To assess antimicrobial use in a defined population of infants and young children and to determine diagnosis-specific prescribing rates for common infections. DESIGN AND SETTING Retrospective cohort study of children served by 44 practices affiliated with 2 managed care organizations. PATIENTS Children aged 3 months to 72 months enrolled in either health plan between September 1, 1994, and August 31, 1996. ANALYSIS Rates of antimicrobial use were calculated as the number of pharmacy dispensings divided by the number of person-years of observation contributed to the cohort in 2 age groups (3 to <36 months and 36 to <72 months). Other outcomes included the distribution of diagnoses associated with antimicrobial dispensing and population-based rates of diagnosis of common acute respiratory tract illnesses. RESULTS A total of 46477 children contributed 59710 person-years of observation across the 2 health plans. Rates of antimicrobial dispensing for children aged 3 to 36 months were 3.2 and 2.1 dispensings per person-year in the 2 populations. A substantial fraction of younger children (35% in population A and 23% in population B) received 4 or more antimicrobial prescriptions in a single year. For children aged 36 to 72 months, the dispensing rates for the 2 populations were 2.0 and 1.5 antimicrobials per person-year. We found significant differences in rates between the populations studied and a decrease in use at all sites from 1995 to 1996. The diagnosis of otitis media accounted for 56% of antimicrobial drugs dispensed to children aged 3 to 36 months and 40% of those dispensed to children aged 36 to 72 months. Antimicrobial prescribing for colds and upper respiratory tract infections, bronchitis, and sinusitis was less frequent than previously reported but accounted for 10% to 14% of antimicrobial drugs dispensed. CONCLUSIONS In these populations, otitis media accounted for the largest number of antimicrobial agents dispensed to children younger than 6 years. Clearly inappropriate indications such as cold, upper respiratory tract infection, and bronchitis accounted for smaller fractions of antimicrobial use but may be most amenable to change. However, interventions that encourage use of strict criteria for diagnosis and treatment of otitis media will likely have the greatest impact on overall antimicrobial exposure. Monitoring defined populations longitudinally will allow assessment of the effectiveness of such national and local initiatives.
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Affiliation(s)
- J A Finkelstein
- Department of Ambulatory Care and Prevention, Harvard Medical School and Harvard Pilgrim Health Care, Boston, Mass 02215, USA
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Metlay JP, Hofmann J, Cetron MS, Fine MJ, Farley MM, Whitney C, Breiman RF. Impact of penicillin susceptibility on medical outcomes for adult patients with bacteremic pneumococcal pneumonia. Clin Infect Dis 2000; 30:520-8. [PMID: 10722438 DOI: 10.1086/313716] [Citation(s) in RCA: 180] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
The impact of penicillin susceptibility on medical outcomes for adult patients with bacteremic pneumococcal pneumonia was evaluated in a retrospective cohort study conducted during population-based surveillance for invasive pneumococcal disease in the greater Atlanta region during 1994. Of the 192 study patients, 44 (23%) were infected with pneumococcal strains that demonstrated some degree of penicillin nonsusceptibility. Compared with patients infected with penicillin-susceptible pneumococcal strains, patients whose isolates were nonsusceptible had a significantly greater risk of in-hospital death due to pneumonia (relative risk [RR], 2.1; 95% confidence interval [CI], 1-4.3) and suppurative complications of infection (RR, 4.5; 95% CI, 1-19.3), although only risk of suppurative complications remained statistically significant after adjustment for baseline differences in severity of illness. Among adults with bacteremic pneumococcal pneumonia, infection with penicillin-nonsusceptible pneumococci is associated with an increased risk of adverse outcome.
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Affiliation(s)
- J P Metlay
- Veterans Affairs Medical Center and University of Pennsylvania School of Medicine, Philadelphia, PA, 19104, USA.
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Halm EA, Atlas SJ, Borowsky LH, Benzer TI, Metlay JP, Chang YC, Singer DE. Understanding physician adherence with a pneumonia practice guideline: effects of patient, system, and physician factors. Arch Intern Med 2000; 160:98-104. [PMID: 10632310 DOI: 10.1001/archinte.160.1.98] [Citation(s) in RCA: 135] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND Adherence with clinical practice guidelines is highly variable. Reasons for their inconsistent performance have not been well studied. OBJECTIVE To determine the patient, system, and physician factors that may explain why physicians may not follow guidelines. METHODS We used chart review and physician surveys to measure adherence with an actively implemented guideline to reduce hospitalizations for patients coming to the emergency department with community-acquired pneumonia. Logistic regression analyses were used to identify factors associated with guideline nonadherence. RESULTS Overall nonadherence with the guideline was 43.6%, with 71 of 163 low-risk patients with pneumonia being hospitalized despite the recommendation for outpatient therapy. In univariate analyses, nonadherence to the guideline was more likely for patients who were aged 65 years or older, were male, were employed, and had multilobar disease or other comorbid conditions (P<.05). Active involvement of a primary care physician in the admission decision also increased nonadherence (odds ratio, 4.9; 95% confidence interval, 2.2-11.0). Physicians with more pneumonia experience were more likely not to follow the guideline (P<.001). In multivariate models, the odds of nonadherence were 2 to 3 times greater when patients were 65 years or older, were male, or had multilobar disease, or the primary care physician was involved in the triage decision (P<.05). Physicians' reasons for admission were the presence of active comorbidities (55%), the primary care physician's wish for hospitalization (41%), the presence of worse pneumonia than the guideline indicated (36%), patient preference (17%), and inadequate home support (16%). CONCLUSIONS Nonadherence to a pneumonia guideline was associated with a variety of patient, system, and physician factors. Guideline implementation strategies should take into account the heterogeneous forces that can influence physician decision making.
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Affiliation(s)
- E A Halm
- Department of Health Policy, Mount Sinai Medical Center, New York, NY 10029, USA.
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Metlay JP, Stafford RS, Singer DE. National trends in the use of antibiotics by primary care physicians for adult patients with cough. Arch Intern Med 1998; 158:1813-8. [PMID: 9738612 DOI: 10.1001/archinte.158.16.1813] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND Increased antibiotic use for outpatient illnesses has been identified as an important determinant of the recent rise in antibiotic resistance among common respiratory pathogens. Efforts to reduce the inappropriate use will need to be evaluated against current trends in the outpatient use of antibiotics. OBJECTIVES To examine national trends in the use of antibiotics by primary care physicians in the care of adult patients with cough and identify patient factors that may influence antibiotic use for these patients. METHODS This study was based on a serial analysis of results from all National Ambulatory Medical Care Surveys beginning in 1980 (when therapeutic drug use was first recorded) to 1994 (the most recent survey year available). These surveys are a random sampling of visits to US office-based physicians in 1980, 1981, 1985, and annually from 1989-1994. Eligible visits included those by adults presenting to general internists, family practitioners, or general practitioners with a chief complaint of cough. A total of 3416 visits for cough were identified over the survey years. Survey results were extrapolated, based on sampling weights in each year, to project national rates of antibiotic use for patients with cough. Additional analyses examined the rates of antibiotic use stratified by patient age, race, and clinical diagnosis. RESULTS Overall, an antibiotic was prescribed 66% of the time during office visits for patients with cough: 59% of patient visits in 1980 rising to 70% of visits in 1994 (P = .002 for trend). In every study year, white, non-Hispanic patients and patients younger than 65 years were more likely to receive antibiotics compared with nonwhite patients and patients 65 years or older, respectively. CONCLUSIONS The rate of antibiotic use by primary care physicians for patients with cough remained high from 1980 to 1994, and was influenced by nonclinical characteristics of patients.
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Affiliation(s)
- J P Metlay
- General Medicine Division, Massachusetts Division, Massachusetts General Hospital and Harvard Medical School, Boston, USA.
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Abstract
The majority of patients with community-acquired pneumonia are at low risk for short-term mortality or serious morbidity and are increasingly managed in the outpatient setting. Efforts to improve the quality of care for these patients will need to measure patient outcomes such as disease-specific symptom resolution. The aims of this study were to (1) develop a self-administered daily version of a symptom questionnaire for patients with pneumonia, (2) measure the reliability of this instrument, and (3) provide estimates for recovery rates based on symptom resolution in a cohort of low-risk patients with community-acquired pneumonia. This study was conducted as part of a prospective study of a new emergency department protocol for pneumonia at the Massachusetts General Hospital. Eligible study subjects included all adult patients with pneumonia presenting to the emergency department with a predicted low risk of short-term mortality. The main outcome measures were based on a new five item symptom questionnaire which rates the severity of cough, fatigue, dyspnea, myalgia, and fever. The questionnaires were self-administered on days 0-7, 14, 21 and 28 from the time of diagnosis of pneumonia. The symptom questions were also administered during patient interviews on days 0, 7, 14 and 28 in order to assess the questionnaire's reliability. Of the 166 eligible patients, 134 (81%) consented to participate in this study. The mean intra-class reliability coefficient of the symptom questionnaire was 0.75. The median times to resolution of individual symptoms ranged from 3 days for fever to 14 days for cough and fatigue. Thirty-five percent of patients had at least one symptom still present at the end of the 28-day study period. We found that a daily self-report questionnaire is a reliable measure of symptom resolution for patients with pneumonia. Full resolution of symptoms takes more than 28 days for a significant proportion of patients with pneumonia.
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Affiliation(s)
- J P Metlay
- Division of General Internal Medicine, University of Pennsylvania School of Medicine, Philadelphia, USA
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Atlas SJ, Benzer TI, Borowsky LH, Chang Y, Burnham DC, Metlay JP, Halm EA, Singer DE. Safely increasing the proportion of patients with community-acquired pneumonia treated as outpatients: an interventional trial. Arch Intern Med 1998; 158:1350-6. [PMID: 9645830 DOI: 10.1001/archinte.158.12.1350] [Citation(s) in RCA: 167] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND Patients with community-acquired pneumonia who are at low risk for short-term mortality can be identified using a validated prediction rule, the Pneumonia Severity Index. Such patients should be candidates for outpatient treatment, yet many are hospitalized. OBJECTIVE To assess a program to safely increase the proportion of low-risk patients with pneumonia treated at home. METHODS The intervention provided physicians with the Pneumonia Severity Index score and corresponding mortality risk for eligible patients and offered enhanced visiting nurse services and the antibiotic clarithromycin. Prospectively enrolled, consecutive low-risk patients with pneumonia presenting to an emergency department during the intervention period (n = 166) were compared with consecutive retrospective controls (n = 147) identified during the prior year. A second group of 208 patients from the study hospital who participated in the Pneumonia Patient Outcomes Research Team cohort study served as controls for patient-reported measures of recovery. RESULTS There were no significant baseline differences between patients in the intervention and control groups. The percentage initially treated as outpatients increased from 42% in the control period to 57% in the intervention period (36% relative increase; 95% confidence interval, 8%-72%; P = .01). However, more outpatients during the intervention period were subsequently admitted to the study hospital (9% vs 0%). When any admission to the study hospital within 4 weeks of presentation was considered, there was a trend toward more patients receiving all their care as outpatients in the intervention group (42% vs 52%; 25% relative increase; 95% confidence interval -2% to 59%; P = .07). No patient in the intervention group died in the 4-week follow-up period. Symptom resolution and functional status were not diminished. Satisfaction with overall care was similar, but patients treated in the outpatient setting during the intervention were less frequently satisfied with the initial treatment location than comparable control patients (71% vs 90%; P = .04). CONCLUSIONS Use of a risk-based algorithm coupled with enhanced outpatient services effectively identified low-risk patients with community-acquired pneumonia in the emergency department and safely increased the proportion initially treated as outpatients. Outpatients in the intervention group were more likely to be subsequently admitted than were controls, lessening the net impact of the intervention.
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Affiliation(s)
- S J Atlas
- Medical Practices Evaluation Center and the General Medicine Division, Medical Services, Massachusetts General Hospital, Harvard Medical School, Boston 02114, USA.
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Metlay JP, Schulz R, Li YH, Singer DE, Marrie TJ, Coley CM, Hough LJ, Obrosky DS, Kapoor WN, Fine MJ. Influence of age on symptoms at presentation in patients with community-acquired pneumonia. Arch Intern Med 1997; 157:1453-9. [PMID: 9224224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Advanced age has become a well-recognized risk factor for death in patients with pneumonia. It may also be associated with reduced symptom reporting, raising the possibility that diagnosis and treatment may be delayed in older patients. OBJECTIVE To evaluate the association between age and the presenting symptoms in patients with community-acquired pneumonia. METHODS This study was conducted at inpatient and outpatient facilities at 3 university hospitals, 1 community hospital, and 1 staff-model health maintenance organization. Patients included adults (age > or = 18 years) with clinical and radiographic evidence of pneumonia, who were able to complete a baseline interview. The presence of 5 respiratory symptoms and 13 nonrespiratory symptoms were recorded during a baseline patient interview. A summary symptom score was computed as the total number of symptoms at presentation. RESULTS The 1812 eligible study patients were categorized into 4 age groups: 18 through 44 years (43%), 45 through 64 years (25%), 65 through 74 years (17%), and 75 years or older (15%). For 17 of the 18 symptoms, there were significant decreases in reported prevalence with increasing age (P < .01). In a linear regression analysis, controlling for patient demographics, comorbidity, and severity of illness at presentation, older age remained associated with lower symptom scores (P < .001). CONCLUSIONS Respiratory and nonrespiratory symptoms are less commonly reported by older patients with pneumonia, even after controlling for the increased comorbidity and illness severity in these older patients. Recognition of this phenomenon by clinicians and patients is essential given the increased mortality in elderly patients with pneumonia.
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Affiliation(s)
- J P Metlay
- Department of Medicine, Massachusetts General Hospital, Boston, USA
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Abstract
OBJECTIVE To determine the rates of resolution of symptoms and return to premorbid health status and assess the association of these outcomes with health care utilization in patients with community-acquired pneumonia. DESIGN A prospective, multicenter cohort study. SETTING Inpatient and outpatient facilities at three university hospitals, one community hospital, and one staff-model health maintenance organization. PATIENTS Five hundred seventy-six adults (aged > or = 18 years) with clinical and radiographic evidence of pneumonia, judged by a validated pneumonia severity index to be at low risk of dying. MEASUREMENTS AND MAIN RESULTS The presence and severity of five symptoms (cough, fatigue, dyspnea, sputum, and chest pain) were recorded through questionnaires administered at four time points: 0, 7, 30, and 90 days from the time of radiographic diagnosis of pneumonia. A summary symptom score was tabulated as the sum of the five individual severity scores. Patients also provided responses to the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36) and reported the number of and reason for outpatient physician visits. Symptoms and health status 30 days before pneumonia onset (prepneumonia) were obtained at the initial interview. All symptoms, except pleuritic chest pain, were still commonly reported at 30 days, and the prevalence of each symptom at 90 days was still nearly twice prepneumonia levels. Physical health measures derived from the SF-36 Form declined significantly at presentation but continued to improve over all three follow-up time periods. Patients with elevated symptom scores at day 7 or day 30 were significantly more likely to report pneumonia-related ambulatory care visits at the subsequent day 30 or day 90 interviews, respectively. CONCLUSIONS Disease-specific symptom resolution and recovery of the premorbid physical health status requires more than 30 days for many patients with pneumonia. Delayed resolution of symptoms is associated with increased utilization of outpatient physician visits.
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Affiliation(s)
- J P Metlay
- Department of Medicine, Massachusetts General Hospital, Boston 02114, USA
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Halm EA, Metlay JP, Singer DE, Fine MJ. Community-acquired pneumonia. N Engl J Med 1996; 334:862; author reply 862-3. [PMID: 8596559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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Agger R, Witmer-Pack M, Romani N, Stossel H, Swiggard WJ, Metlay JP, Storozynsky E, Freimuth P, Steinman RM. Two populations of splenic dendritic cells detected with M342, a new monoclonal to an intracellular antigen of interdigitating dendritic cells and some B lymphocytes. J Leukoc Biol 1992; 52:34-42. [PMID: 1379295 DOI: 10.1002/jlb.52.1.34] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
A monoclonal has been isolated that labels an intracellular antigen in dendritic cells and some B cells. The M342 hamster immunoglobulin was selected because it stained cells in the periarterial sheaths of spleen, the deep cortex of lymph node, and the thymic medulla--the same regions in which one finds interdigitating cells, the presumptive in situ counterparts of isolated lymphoid dendritic cells. M342 labeled an antigen within granules of isolated dendritic cells, but only in cells that had been cultured for a day and not in fresh isolates. This extends recent findings that most freshly isolated spleen dendritic cells are located in the periphery of the white pulp nodule and may serve as precursors for the periarterial pool of interdigitating cells, the site for M342 staining in situ. By electron microscopic immunolabeling, the M342 antigen was found exclusively in a type of multivesicular body. M342 staining was not found in mononuclear phagocytes from blood and peritoneal cavity. Peritoneal B cells expressed M342+ granules, and upon appropriate stimulation splenic B cells developed reactive granules as well. We conclude that M342 is a strong marker for interdigitating cells. Its existence reveals intracellular specializations in the vacuolar system of antigen-presenting cells including subsets of dendritic cells.
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Affiliation(s)
- R Agger
- Laboratory of Cellular Physiology and Immunology, Rockefeller University, New York, NY 10021
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Abstract
The metabolism of IgG immunoglobulins in the body is tightly regulated in order to maintain their intravascular concentration. Different subclasses may have different intravascular half-lives, and in the mouse, passively administered IgG2b disappears from the circulation more rapidly than IgG2a. We have attempted to localize the sequences in the constant region which are responsible for this difference by examining the intravascular metabolism of mutant immunoglobulins that were generated in tissue culture and have undergone deletions of individual constant region domains or contain different combinations of gamma 2b and gamma 2a CH2 and CH3 domains. Our results suggest that the regulation of intravascular metabolism is complex but indicate that sequences in the CH3 domain are important in determining the different intravascular half-lives of IgG2b and IgG2a antibodies in the mouse.
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Affiliation(s)
- R R Pollock
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461
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Inaba K, Metlay JP, Crowley MT, Steinman RM. Dendritic cells pulsed with protein antigens in vitro can prime antigen-specific, MHC-restricted T cells in situ. J Exp Med 1990; 172:631-40. [PMID: 2373994 PMCID: PMC2188342 DOI: 10.1084/jem.172.2.631] [Citation(s) in RCA: 490] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
T cells recognize peptides that are bound to MHC molecules on the surface of different types of antigen-presenting cells (APC). Antigen presentation most often is studied using T cells that have undergone priming in situ, or cell lines that have been chronically stimulated in vitro. The use of primed cells provides sufficient numbers of antigen-reactive lymphocytes for experimental study. A more complete understanding of immunogenicity, however, requires that one develop systems for studying the onset of a T cell response from unprimed lymphocytes, especially in situ. Here it is shown that mouse T cells can be reliably primed in situ using dendritic cells as APC. The dendritic cells were isolated from spleen, pulsed with protein antigens, and then administered to naive mice. Antigen-responsive T cells developed in the draining lymphoid tissue, and these T cells only recognized protein when presented on cells bearing the same MHC products as the original priming dendritic cells. In contrast, little or no priming was seen if antigen-pulsed spleen cells or peritoneal cells were injected. Since very small amounts of the foreign protein were visualized within endocytic vacuoles of antigen-pulsed dendritic cells, it is suggested that dendritic cells have a small but relevant vacuolar system for presenting antigens over a several day period in situ.
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Affiliation(s)
- K Inaba
- Rockefeller University, Irvington Institute, New York, New York 10021
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Metlay JP, Witmer-Pack MD, Agger R, Crowley MT, Lawless D, Steinman RM. The distinct leukocyte integrins of mouse spleen dendritic cells as identified with new hamster monoclonal antibodies. J Exp Med 1990; 171:1753-71. [PMID: 2185332 PMCID: PMC2187889 DOI: 10.1084/jem.171.5.1753] [Citation(s) in RCA: 435] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Hybridoma fusions with hamster hosts were undertaken to generate mAbs to mouse spleen dendritic cells. Two mAb were obtained and used to uncover the distinct integrins of these APC. One, 2E6, bound a determinant common to all members of the CD11/CD18 family, most likely the shared 90 kD CD18 beta chain. 2E6 immunoprecipitated the characteristic beta 2 integrin heterodimers from lymphocytes (p180, 90; CD11a) and macrophages (p170,90; CD11b), but from dendritic cells, a p150,90 (presumably CD11c) integrin was the predominant species. 2E6 inhibited the binding function of the CD11a and CD11b integrins on B cells and macrophages in appropriate assays, but 2E6 exerted little or no inhibition on the clustering of dendritic cells to T cells early in primary MLR, suggesting a CD11/CD18-independent mechanism for this binding. The second mAb, N418, precipitated a 150, 90 kD heterodimer that shared the 2E6 CD18 epitope. This N418 epitope may be the murine homologue of the previously characterized human CD11c molecule, but the epitope was only detected on dendritic cells. N418 did not react with peritoneal macrophages, anti-Ig-induced spleen B blasts, or bulk lymph node cells. When used to stain sections of spleen, N418 stained dendritic cells in the T-dependent areas, much like anti-class II mAbs that were also generated in these fusions. In addition, N418 revealed nests of dendritic cells that punctuated the rim of marginal zone macrophages between red and white pulp. This localization positioned most dendritic cells at regions where arterial vessels and T cells enter the white pulp. We conclude that the p150, 90 heterodimer is the major beta 2 integrin of spleen dendritic cells, and we speculate that it may function to localize these APC at sites that permit access to the recirculating pool of resting T cells.
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Affiliation(s)
- J P Metlay
- Rockefeller University, New York, New York 10021
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Abstract
The biology of antigen presenting cells (APC) traditionally is studied in tissue culture systems using T cells that have been expanded beforehand by stimulation with antigen. Here we consider the distinctive roles of dendritic cells for sensitizing or priming T cells both in vitro and in vivo. Several functions of dendritic cells have been identified in tissue culture that are pertinent to T cell sensitization. These include the ability to a) capture and retain foreign antigens in an immunogenic form, b) bind antigen-specific resting lymphocytes, and c) activate T cells to produce lymphokines and undergo long term clonal growth. Dendritic cells have several properties in vivo that also would contribute to APC function. These are a) their widespread tissue distribution permitting access to antigens in most organs, b) the capacity to home via the blood stream and afferent lymph to the T-dependent areas of spleen and lymph node, and c) the ability to capture antigen in antigen-pulsed animals. Dendritic cells bearing antigen have been administered in situ to initiate responses like contact sensitivity, graft rejection, and antibody formation. A most striking recent example is that, when dendritic cells are pulsed with protein antigens in vitro and administered to immunologically naive mice, there is direct priming of antigen-specific T cells that are restricted to the MHC of the injected APC.
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Affiliation(s)
- K Inaba
- Department of Zoology, Faculty of Science, Kyoto University, Japan
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Metlay JP, Puré E, Steinman RM. Control of the immune response at the level of antigen-presenting cells: a comparison of the function of dendritic cells and B lymphocytes. Adv Immunol 1989; 47:45-116. [PMID: 2554698 DOI: 10.1016/s0065-2776(08)60662-8] [Citation(s) in RCA: 119] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- J P Metlay
- Rockefeller University, New York, New York 10021
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Abstract
Highly enriched populations of B lymphoblasts have been isolated after culture with anti-Ig-Sepharose and compared with dendritic cells as stimulators of CD4+ T cells in the murine MLR. The two populations clearly differed in phenotype; anti-Ig blasts were FcR+, B220+, 33D1-, while dendritic cells were FcR-, B220-, 33D1+. However, as MLR stimulators, they shared many common features. Both cells (a) expressed comparable levels of class II MHC products; (b) independently stimulated the primary MLR and the production of several T derived lymphokines including IL-2 and IL-4; and (c) were comparable in stimulating freshly sensitized T cells. However, the relative potencies of dendritic cells and anti-Ig blasts as primary MLR stimulators varied in a strain-dependent fashion. Only anti-Ig blasts could stimulate across an Mls barrier, being at least 100 times more active in stimulating Mls-mismatched, MHC-matched T cells, relative to syngeneic T cells. In contrast, dendritic cells were 10-30 times more potent than anti-Ig blasts when stimulating across an MHC barrier and were likewise more effective in binding MHC-disparate T cells to form the clusters in which the MLR was generated. Dendritic cell-T cell clustering was resistant to anti-LFA-1 mAb, while B blast-T cell clustering was totally blocked. Thus, anti-Ig B lymphoblasts and dendritic cells, two cell types which differ markedly in phenotype, also differ in efficiency and mechanism for initiating responses in allogeneic T cells.
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Affiliation(s)
- J P Metlay
- Rockefeller University, New York, New York
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