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Farley JE, McKenzie-White J, Bollinger R, Hong H, Lowensen K, Chang LW, Stamper P, Berrie L, Olsen F, Isherwood L, Ndjeka N, Stevens W. Evaluation of miLINC to shorten time to treatment for rifampicin-resistant Mycobacterium tuberculosis. Int J Tuberc Lung Dis 2019; 23:980-988. [PMID: 31615604 DOI: 10.5588/ijtld.18.0503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND: Achieving the 90-90-90 targets for tuberculosis (TB) will require interventions that enhance diagnosis, linkage, treatment and adherence to care. As a first step in the process, our team designed a suite of smartphone applications known as miLINC to improve time from diagnosis to treatment initiation in drug-resistant TB patients.SETTING: Three clinical locations in a large, peri-urban district in KwaZulu-Natal, South Africa.OBJECTIVE: To assess the acceptability, feasibility and impact of the miLINC mobile health applications as a solution to reducing the time from presentation to treatment initiation of rifampicin-resistant (RR) TB patients.METHODS: We used a prospective, observational quality improvement evaluation of miLINC's impact among newly diagnosed patients with RR-TB.RESULTS: A convenience sample comprising details of 6341 patients with presumptive TB were entered into miLINC. Of the 631 TB-positive sputum specimens, 41 (6.5%) were found to be RR-TB. The mean time from clinical presentation to RR-TB treatment initiation was 3 days, 21 h, 17 min.CONCLUSION: This is the first study to suggest that the time from presentation to diagnosis and to treatment initiation for patients with RR-TB can be significantly improved using an integrated approach combining technology with appropriate human resources.
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Affiliation(s)
- J E Farley
- REACH Initiative, Johns Hopkins University School of Nursing, Baltimore, MD, Department of Community Public Health, Johns Hopkins University School of Nursing, Baltimore, MD
| | - J McKenzie-White
- Johns Hopkins Center for Clinical Global Health Education, Baltimore, MD, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - R Bollinger
- Johns Hopkins Center for Clinical Global Health Education, Baltimore, MD, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - H Hong
- REACH Initiative, Johns Hopkins University School of Nursing, Baltimore, MD, Department of Community Public Health, Johns Hopkins University School of Nursing, Baltimore, MD
| | - K Lowensen
- REACH Initiative, Johns Hopkins University School of Nursing, Baltimore, MD, Department of Community Public Health, Johns Hopkins University School of Nursing, Baltimore, MD
| | - L W Chang
- Johns Hopkins Center for Clinical Global Health Education, Baltimore, MD, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - P Stamper
- REACH Initiative, Johns Hopkins University School of Nursing, Baltimore, MD, Department of Community Public Health, Johns Hopkins University School of Nursing, Baltimore, MD
| | - L Berrie
- National Health Laboratory Service, National Priority Programs Unit, Johannesburg
| | - F Olsen
- National Health Laboratory Service, National Priority Programs Unit, Johannesburg
| | - L Isherwood
- National Health Laboratory Service, National Priority Programs Unit, Johannesburg
| | - N Ndjeka
- South African National Department of Health, Pretoria
| | - W Stevens
- National Health Laboratory Service, National Priority Programs Unit, Johannesburg, University of the Witwatersrand, School of Clinical Medicine, Johannesburg, South Africa
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MacGlashan D, Lichtenstein LM, McKenzie-White J, Chichester K, Henry AJ, Sutton BJ, Gould HJ. Upregulation of FcepsilonRI on human basophils by IgE antibody is mediated by interaction of IgE with FcepsilonRI. J Allergy Clin Immunol 1999; 104:492-8. [PMID: 10452777 DOI: 10.1016/s0091-6749(99)70399-4] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.6] [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: 10/25/2022]
Abstract
BACKGROUND IgE is now known to upregulate the expression of FcepsilonRI on human basophils. It is not known which receptor on basophils mediates this process of upregulation. OBJECTIVE We sought to determine whether galectin-3, FcepsilonRII (CD23), or FcepsilonRI were involved in the upregulation of FcepsilonRI by IgE. METHODS The role of galectin-3 was examined by measuring the influence of alpha-lactose on upregulation. Basophils were examined for expression of FcepsilonRII (CD23) by flow cytometry and messenger (m)RNA expression. Functional discrimination between binding to FcepsilonRII or FcepsilonRI was examined through the use of mutant IgE-Fc fragments or anti-FcepsilonRII antibody. RESULTS Upregulation of FcepsilonRI on basophils in the presence of IgE was not altered by coincubation with alpha-lactose, eliminating a role for galectin-3. Basophils were not found to express FcepsilonRII, as determined by flow cytometry with enriched basophil preparations or RT-PCR with highly purified basophil preparations. A mutant of the Fc fragment of IgE (IgE-Fc), which binds to FcepsilonRI with a greater than 10-fold lower affinity than IgE or wild-type IgE-Fc but exhibits no change in affinity for FcepsilonRII, allowed us to distinguish between the functions of the two Fc receptors. The mutant (R334S; Henry et al 1997) was required at about 30-fold higher concentration than the wild-type IgE-Fc for the same stimulation of FcepsilonRI expression on basophils, thus excluding a role for FcepsilonRII in the response. In addition, treatment of basophils with anti-FcepsilonRII antibody (MHM6), which is known to be competitive with IgE, had no effect on the expression of FcepsilonRI or the ability of IgE to upregulate expression of FcepsilonRI. CONCLUSION Collectively, these data indicate that IgE interacts with FcepsilonRI to upregulate its expression on human basophils.
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Affiliation(s)
- D MacGlashan
- Johns Hopkins Asthma and Allergy Center, Baltimore, MD 21224, USA
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MacGlashan D, McKenzie-White J, Chichester K, Bochner BS, Davis FM, Schroeder JT, Lichtenstein LM. In vitro regulation of FcepsilonRIalpha expression on human basophils by IgE antibody. Blood 1998; 91:1633-43. [PMID: 9473229] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In vivo studies suggested the possibility of an IgE-dependent regulation of high-affinity (FcepsilonRI) IgE receptor expression on basophils. The current studies extend these observations to in vitro cultures of human basophils. Incubation of basophils for 3 to 4 weeks resulted in a slow dissociation of IgE antibody, during which time FcepsilonRI expression decreased, as measured by flow cytometry using the anti-FcepsilonRIalpha monoclonal antibody, 22E7, or by measuring FcRIalpha mass by Western blotting of whole-cell lysates. Culture of basophils with IgE resulted in upregulation of FcepsilonRIalpha expression by both flow cytometry and Western blotting of whole-cell lysates. Upregulation followed a linear time course during 2 weeks of culture. The relative increase in FcepsilonRIalpha density depended on the starting density; with starting densities of FcepsilonRIalpha of 10,000 to 170,000 per basophil, the upregulation varied 20- to 1.1-fold, respectively. Upregulation occurred in high-purity basophils, was not influenced by IgG at concentrations up to 1 mg/mL, and was inhibited by dimeric IgE. Heat-inactivated IgE was less effective and the monoclonal antibody CGP51901 that prevents IgE binding to FcepsilonRIalpha blocked the ability of IgE to induce upregulation. The dose-response curve for IgE-induced upregulation had an effective concentration50 of 230 ng/mL. Although the receptor through which IgE induces this upregulation is not yet known, several characteristics suggest that the upregulation is mediated by IgE interacting through FcepsilonRIalpha itself.
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Affiliation(s)
- D MacGlashan
- Johns Hopkins Asthma and Allergy Center, Baltimore, MD 21224, USA
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4
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MacGlashan DW, Bochner BS, Adelman DC, Jardieu PM, Togias A, McKenzie-White J, Sterbinsky SA, Hamilton RG, Lichtenstein LM. Down-regulation of Fc(epsilon)RI expression on human basophils during in vivo treatment of atopic patients with anti-IgE antibody. The Journal of Immunology 1997. [DOI: 10.4049/jimmunol.158.3.1438] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Treatment of allergic disease by decreasing circulating IgE with anti-IgE Abs is currently under clinical study. Based on previous unrelated studies, it appeared likely that Fc(epsilon)RI expression on basophils and mast cells might also be regulated by levels of circulating IgE Ab. Therefore, the expression of IgE and Fc(epsilon)RI on human basophils was examined in 15 subjects receiving humanized anti-IgE mAb intravenously. Treatment with the anti-IgE mAb decreased free IgE levels to 1% of pretreatment levels and also resulted in a marked down-regulation of Fc(epsilon)RI on basophils. Median pretreatment densities of Fc(epsilon)RI were approximately 220,000 receptors per basophil and after 3 mo of treatment, the densities had decreased to a median of 8,300 receptors per basophil. Flow cytometric studies, conducted in parallel, showed similar results and also showed in a subset of 3 donors that receptors decreased with a t1/2 of approximately 3 days. The responsiveness of the cells to IgE-mediated stimulation using anti-IgE Ab was marginally decreased (approximately 40%) while the response of the same cells to stimulation with dust mite Ag, Dermatophagoides farinae, was reduced by approximately 90%. One possible explanation for these results is that Fc(epsilon)RI density is directly or indirectly regulated by plasma-free IgE levels.
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Affiliation(s)
- D W MacGlashan
- Johns Hopkins Asthma and Allergy Center, Baltimore, MD 21224, USA.
| | - B S Bochner
- Johns Hopkins Asthma and Allergy Center, Baltimore, MD 21224, USA.
| | - D C Adelman
- Johns Hopkins Asthma and Allergy Center, Baltimore, MD 21224, USA.
| | - P M Jardieu
- Johns Hopkins Asthma and Allergy Center, Baltimore, MD 21224, USA.
| | - A Togias
- Johns Hopkins Asthma and Allergy Center, Baltimore, MD 21224, USA.
| | - J McKenzie-White
- Johns Hopkins Asthma and Allergy Center, Baltimore, MD 21224, USA.
| | - S A Sterbinsky
- Johns Hopkins Asthma and Allergy Center, Baltimore, MD 21224, USA.
| | - R G Hamilton
- Johns Hopkins Asthma and Allergy Center, Baltimore, MD 21224, USA.
| | - L M Lichtenstein
- Johns Hopkins Asthma and Allergy Center, Baltimore, MD 21224, USA.
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MacGlashan DW, Bochner BS, Adelman DC, Jardieu PM, Togias A, McKenzie-White J, Sterbinsky SA, Hamilton RG, Lichtenstein LM. Down-regulation of Fc(epsilon)RI expression on human basophils during in vivo treatment of atopic patients with anti-IgE antibody. J Immunol 1997; 158:1438-45. [PMID: 9013989] [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: 02/03/2023]
Abstract
Treatment of allergic disease by decreasing circulating IgE with anti-IgE Abs is currently under clinical study. Based on previous unrelated studies, it appeared likely that Fc(epsilon)RI expression on basophils and mast cells might also be regulated by levels of circulating IgE Ab. Therefore, the expression of IgE and Fc(epsilon)RI on human basophils was examined in 15 subjects receiving humanized anti-IgE mAb intravenously. Treatment with the anti-IgE mAb decreased free IgE levels to 1% of pretreatment levels and also resulted in a marked down-regulation of Fc(epsilon)RI on basophils. Median pretreatment densities of Fc(epsilon)RI were approximately 220,000 receptors per basophil and after 3 mo of treatment, the densities had decreased to a median of 8,300 receptors per basophil. Flow cytometric studies, conducted in parallel, showed similar results and also showed in a subset of 3 donors that receptors decreased with a t1/2 of approximately 3 days. The responsiveness of the cells to IgE-mediated stimulation using anti-IgE Ab was marginally decreased (approximately 40%) while the response of the same cells to stimulation with dust mite Ag, Dermatophagoides farinae, was reduced by approximately 90%. One possible explanation for these results is that Fc(epsilon)RI density is directly or indirectly regulated by plasma-free IgE levels.
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Affiliation(s)
- D W MacGlashan
- Johns Hopkins Asthma and Allergy Center, Baltimore, MD 21224, USA.
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Columbo M, Horowitz EM, McKenzie-White J, Kagey-Sobotka A, Lichtenstein LM. Pharmacologic control of histamine release from human basophils induced by platelet-activating factor. Int Arch Allergy Immunol 1993; 102:383-90. [PMID: 7694703 DOI: 10.1159/000236587] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [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: 01/26/2023] Open
Abstract
We studied the effect of several compounds that influence different cell activation steps on platelet-activating factor (PAF)-induced basophil histamine secretion. Isobutylmethylxanthine (1-100 microM), dimaprit (1-100 microM) and dibutyryl adenosine 3',5'-cyclic phosphate (cAMP; 0.01-1 mM), that increase intracellular cAMP levels, concentration-dependently inhibited PAF-elicited histamine release. Rolipram (phosphodiesterase, PDE, isotype IV inhibitor; 0.1 nM-10 microM) potently inhibited histamine secretion activated by PAF, whereas SKF95654 (PDE III inhibitor; 0.01-10 microM) was ineffective. The kinase inhibitor, staurosporine (0.1-100 nM), enhanced PAF-induced basophil histamine release, whereas the G-protein inhibitor, pertussis toxin (1 microgram/ml), had an inhibitory effect. The specific lipoxygenase inhibitor, AA-861 (0.1-10 microM), inhibited PAF-activated histamine release, while the leukotriene A4 hydrolase inhibitor, bestatin (100 microM), had only a marginal effect. Finally, the Ca2+ channel entry blockers, verapamil (3-30 microM) and zinc (1.5-50 microM), inhibited PAF-induced histamine release. These results suggest that PAF is a unique secretagogue for human basophils unlike antigen, anti-IgE or univalent stimuli.
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Affiliation(s)
- M Columbo
- Division of Clinical Immunology, Johns Hopkins University School of Medicine, Johns Hopkins Asthma and Allergy Center, Baltimore, Md
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Cohan V, McKenzie-White J, Triggiani M, Massey W, Kagey-Sobotka A, Lichtenstein LM. Heterogeneity of human mast cells and basophils. Effects of a putative 5-lipoxygenase inhibitor. Biochem Pharmacol 1989; 38:4455-9. [PMID: 2481451 DOI: 10.1016/0006-2952(89)90656-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [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: 01/01/2023]
Abstract
The effects of a putatively specific 5-lipoxygenase inhibitor, 2(12-hydroxydodeca-5,10-dinyl)-3,5,6-trimethyl-1,4-benzoquin one (AA-861), and its major metabolite, M-I, were assessed using anti-IgE activated human basophils, lung mast cells and skin mast cells. In basophils and lung mast cells, no effects on histamine release were observed, whereas leukotriene C4 (LTC4) production was inhibited (IC50 values less than 1 microM). In addition, prostaglandin D2 (PGD2) production was inhibited in lung mast cells (IC50 congruent to 5 microM). In contrast, in skin mast cells both histamine release and PGD2 production were reduced by AA-861 and M-I, with IC50 values of congruent to 5 and 0.4 microM for histamine and PGD2, respectively. These data reveal biochemical heterogeneity among human histamine-containing cells and underscore the necessity of assessing a pharmacologic agonist in relevant cell systems.
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Affiliation(s)
- V Cohan
- Division of Clinical Immunology, Johns Hopkins University School of Medicine, Good Samaritan Hospital, Baltimore, MD 21239
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