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1.
Ann Acad Med Singap ; 53(3): 170-186, 2024 Mar 27.
Article in English | MEDLINE | ID: mdl-38920244

ABSTRACT

Introduction: Tuberculosis (TB) remains endemic in Singapore. Singapore's clinical practice guidelines for the management of tuberculosis were first published in 2016. Since then, there have been major new advances in the clinical management of TB, ranging from diagnostics to new drugs and treatment regimens. The National TB Programme convened a multidisciplinary panel to update guidelines for the clinical management of drug-susceptible TB infection and disease in Singapore, contextualising current evidence for local practice. Method: Following the ADAPTE framework, the panel systematically reviewed, scored and synthesised English-language national and international TB clinical guidelines published from 2016, adapting recommendations for a prioritised list of clinical decisions. For questions related to more recent advances, an additional primary literature review was conducted via a targeted search approach. A 2-round modified Delphi process was implemented to achieve consensus for each recommendation, with a final round of edits after consultation with external stakeholders. Results: Recommendations for 25 clinical questions spanning screening, diagnosis, selection of drug regimen, monitoring and follow-up of TB infection and disease were formulated. The availability of results from recent clinical trials led to the inclusion of shorter treatment regimens for TB infection and disease, as well as consensus positions on the role of newer technologies, such as computer-aided detection-artificial intelligence products for radiological screening of TB disease, next-generation sequencing for drug-susceptibility testing, and video observation of treatment. Conclusion: The panel updated recommendations on the management of drug-susceptible TB infection and disease in Singapore.


Subject(s)
Antitubercular Agents , Delphi Technique , Tuberculosis, Pulmonary , Tuberculosis , Humans , Singapore , Antitubercular Agents/therapeutic use , Tuberculosis, Pulmonary/drug therapy , Tuberculosis, Pulmonary/diagnosis , Tuberculosis/drug therapy , Tuberculosis/diagnosis , Consensus
2.
Cancers (Basel) ; 15(18)2023 Sep 19.
Article in English | MEDLINE | ID: mdl-37760594

ABSTRACT

INTRODUCTION: Chemotherapy is complex. We hypothesized that a design thinking approach could redesign preparatory processes and reduce wait times. METHODS: A multidisciplinary process mapping exercise was undertaken to understand the current processes, followed by proposing and testing solutions. Proposals were selected based on desirability and feasibility. These focused on starting the morning treatments on time and scheduling pre-made regimens in these slots. The primary outcome measure was the time from the appointment to starting treatment. Treatments in the post-intervention study group were compared against a historical control group. RESULTS: The median time to start morning treatment decreased by 46%, from 83 min (with an interquartile range 50-127) in the control group to 45 min (with an interquartile range of 24-81 min) in the study group (p < 0.001). This translated into an overall improvement for the day, with the median time to start treatment decreasing from 77 min (with an interquartile range of 40-120 min) to 47 min (with an interquartile range of 20-79 min) (p < 0.001). Pre-makes increased by 258%, from 908 (28.5%) to 2340 (71.7%) regimens (p < 0.001). The number of patients starting treatment within an hour of their appointment increased from 1688 (32.8%) to 3355 (62.3%, p < 0.001). CONCLUSION: We have shown that a data-driven, design thinking approach can improve waiting times. This can be adapted to improve other processes in an empathetic, sustainable manner.

3.
Harm Reduct J ; 20(1): 110, 2023 08 16.
Article in English | MEDLINE | ID: mdl-37587466

ABSTRACT

BACKGROUND: The opioid crisis continues in full force, as physicians and caregivers are desperate for resources to help patients with opioid use and chronic pain disorders find safer and more accessible non-opioid tools. MAIN BODY: The purpose of this article is to review the current state of the opioid epidemic; the shifting picture of cannabinoids; and the research, policy, and current events that make opioid risk reduction an urgent public health challenge. The provided table contains an evidence-based clinical framework for the utilization of cannabinoids to treat patients with chronic pain who are dependent on opioids, seeking alternatives to opioids, and tapering opioids. CONCLUSION: Based on a comprehensive review of the literature and epidemiological evidence to date, cannabinoids stand to be one of the most interesting, safe, and accessible tools available to attenuate the devastation resulting from the misuse and abuse of opioid narcotics. Considering the urgency of the opioid epidemic and broadening of cannabinoid accessibility amidst absent prescribing guidelines, the authors recommend use of this clinical framework in the contexts of both clinical research continuity and patient care.


Subject(s)
Chronic Pain , Epidemics , Humans , Analgesics, Opioid/therapeutic use , Opioid Epidemic , Chronic Pain/drug therapy , Narcotics
4.
Cells ; 12(8)2023 04 15.
Article in English | MEDLINE | ID: mdl-37190076

ABSTRACT

(1) Background: Cell injection therapy is an emerging treatment for bullous keratopathy (BK). Anterior segment optical coherence tomography (AS-OCT) imaging allows the high-resolution assessment of the anterior chamber. Our study aimed to investigate the predictive value of the visibility of cellular aggregates for corneal deturgescence in an animal model of bullous keratopathy. (2) Methods: Cell injections of corneal endothelial cells were performed in 45 eyes in a rabbit model of BK. AS-OCT imaging and central corneal thickness (CCT) measurement were performed at baseline and on day 1, day 4, day 7 and day 14 following cell injection. A logistic regression was modelled to predict successful corneal deturgescence and its failure with cell aggregate visibility and CCT. Receiver-operating characteristic (ROC) curves were plotted, and areas under the curve (AUC) calculated for each time point in these models. (3) Results: Cellular aggregates were identified on days 1, 4, 7 and 14 in 86.7%, 39.5%, 20.0% and 4.4% of eyes, respectively. The positive predictive value of cellular aggregate visibility for successful corneal deturgescence was 71.8%, 64.7%, 66.7% and 100.0% at each time point, respectively. Using logistic regression modelling, the visibility of cellular aggregates on day 1 appeared to increase the likelihood of successful corneal deturgescence, but this did not reach statistical significance. An increase in pachymetry, however, resulted in a small but statistically significant decreased likelihood of success, with an odds ratio of 0.996 for days 1 (95% CI 0.993-1.000), 2 (95% CI 0.993-0.999) and 14 (95% CI 0.994-0.998) and an odds ratio of 0.994 (95% CI 0.991-0.998) for day 7. The ROC curves were plotted, and the AUC values were 0.72 (95% CI 0.55-0.89), 0.80 (95% CI 0. 62-0.98), 0.86 (95% CI 0.71-1.00) and 0.90 (95% CI 0.80-0.99) for days 1, 4, 7 and 14, respectively. (4) Conclusions: Logistic regression modelling of cell aggregate visibility and CCT was predictive of successful corneal endothelial cell injection therapy.


Subject(s)
Cornea , Endothelial Cells , Animals , Rabbits , Cornea/diagnostic imaging , Corneal Pachymetry/methods
6.
Hematol Oncol Stem Cell Ther ; 11(4): 225-232, 2018 Dec.
Article in English | MEDLINE | ID: mdl-29705566

ABSTRACT

BACKGROUND: High dose Cyclophosphamide (Cy) and Vinorelbine Cyclophosphamide (Vino-Cy) are stem cell (SC) mobilisation options for patients with multiple myeloma (MM). We present a comparison of mobilisation outcomes using these regimens. PATIENTS AND METHODS: Vino-Cy patients received Vinorelbine 25 mg/m2 on day 1, cyclophosphamide 1500 mg/m2 on day 2, and pegylated GCSF on day 4 or GCSF 10 mcg/kg/day from day 4 onwards. Cy patients were given cyclophosphamide 4000 mg/m2 on day 1 and GCSF10 mcg/kg/day from day 5 onwards. The target CD34 + SC collection was 5 × 106 per kg/BW. RESULTS: 149 patients were included. SC collection was lower in the Vino-Cy group (8.20 × 106/Kg BW) compared to the Cy group (11.43 × 106/Kg BW), with adjusted geometric mean ratio of 0.59 (95% CI 0.41 to 0.86, p = 0.006). Time taken to achieve an adequate PB SC count was shorter for Vino-Cy (9 ±â€¯1 day compared to 12 ±â€¯2 days for Cy, adjusted absolute mean difference -3.95, 95% CI -4.85 to -3.06, P < .001). Mobilisation related toxicities (in particular, neutropaenic fever) were greater for Cy. CONCLUSION: Vino-Cy is a potential alternative to Cy given the need for effective mobilisation protocols with acceptable toxicity.


Subject(s)
Cyclophosphamide/administration & dosage , Hematopoietic Stem Cell Mobilization/methods , Multiple Myeloma/therapy , Peripheral Blood Stem Cells , Vinorelbine/administration & dosage , Autografts , Cyclophosphamide/adverse effects , Female , Filgrastim , Humans , Male , Middle Aged , Multiple Myeloma/blood , Peripheral Blood Stem Cell Transplantation , Vinorelbine/adverse effects
7.
JAMA Dermatol ; 154(2): 188-190, 2018 02 01.
Article in English | MEDLINE | ID: mdl-29261843

ABSTRACT

Importance: Teledermatology has undergone exponential growth in the past 2 decades. Many technological innovations are becoming available without necessarily undergoing validation studies for specific dermatologic applications. Objective: To determine whether patient-taken photographs of acne using Network Oriented Research Assistant (NORA) result in similar lesion counts and Investigator's Global Assessment (IGA) findings compared with in-person examination findings. Design, Setting, and Participants: This pilot reliability study enrolled consecutive patients with acne vulgaris from a single general dermatology practice in Los Angeles, California, who were able to use NORA on an iPhone 6 to take self-photographs. Patients were enrolled from January 1 through March 31, 2016. Each individual underwent in-person and digital evaluation of his or her acne by the same dermatologist. A period of at least 1 week separated the in-person and digital assessments of acne. Interventions: All participants were trained on how to use NORA on the iPhone 6 and take photographs of their face with the rear-facing camera. Main Outcomes and Measures: Reliability of patient-taken photographs with NORA for acne evaluation compared with in-person examination findings. Acne assessment measures included lesion count (total, inflammatory, noninflammatory, and cystic) and IGA for acne severity. Results: A total of 69 patients (37 male [54%] and 32 female [46%]; mean [SD] age, 22.7 [7.7] years) enrolled in the study. The intraclass correlation coefficients of in-person and photograph-based acne evaluations indicated strong agreement. The intraclass correlation coefficient for total lesion count was 0.81; for the IGA, 0.75. Inflammatory lesion count, noninflammatory lesion count, and cyst count had intraclass correlation coefficients of 0.72, 0.72, and 0.82, respectively. Conclusions and Relevance: This study found agreement between acne evaluations performed in person and from self-photographs with NORA. As a reliable telehealth technology for acne, NORA can be used as a teledermatology platform for dermatology research and can increase access to dermatologic care.


Subject(s)
Acne Vulgaris/diagnosis , Cell Phone/statistics & numerical data , Photography/methods , Telemedicine/methods , Adult , California , Cohort Studies , Dermatology/methods , Female , Humans , Male , Physical Examination/methods , Pilot Projects , Research Design , Sensitivity and Specificity
8.
Dermatol Online J ; 19(9): 19609, 2013 Sep 14.
Article in English | MEDLINE | ID: mdl-24050284

ABSTRACT

Psoriasis is a chronic, auto-inflammatory disease affecting millions of individuals worldwide. In addition to classic cutaneous manifestations, the condition is linked to significant co-morbidities including cardiovascular disease, metabolic syndrome, melanoma and non-melanoma skin cancer, and psychiatric disease. Therefore, more aggressive treatment and multi-disciplinary care is critical. Measures of disease burden (quantified by anatomic location, body surface area (BSA) of involvement, and impact on daily life) assist in determining the severity of disease and have been integral in objective assessment of treatment regimens and new drug therapies. Biologic agents have entered the clinical armamentarium as treatment options for patients with moderate-to-severe psoriasis who have failed traditional systemic therapies. Three of the four FDA-approved biologic agents for psoriasis suppress TNF-α mediated pathways, which are essential for granuloma formation and maintenance, key components of host defenses against intracellular pathogens. Subsequently, the increased use of these agents is accompanied by increased reporting of granulomatous infectious diseases such as tuberculosis, histoplasmosis, nocardia, and nontuberculous mycobacteria. Report of any unusual infection is therefore vitally important in the care of this immune suppressed patient population.


Subject(s)
Immunoglobulin G/adverse effects , Immunosuppressive Agents/adverse effects , Leg Ulcer/microbiology , Mycobacterium Infections, Nontuberculous/etiology , Nontuberculous Mycobacteria/isolation & purification , Psoriasis/drug therapy , Tumor Necrosis Factor-alpha/antagonists & inhibitors , Adult , Animals , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/therapeutic use , Antibodies, Monoclonal, Humanized/therapeutic use , Bacterial Typing Techniques , Cyclosporine/administration & dosage , Cyclosporine/therapeutic use , Drug Therapy, Combination , Etanercept , Female , Fishes/microbiology , Humans , Immunocompromised Host , Immunoglobulin G/administration & dosage , Immunoglobulin G/therapeutic use , Immunosuppressive Agents/administration & dosage , Immunosuppressive Agents/therapeutic use , Interferon-gamma Release Tests , Leg Ulcer/etiology , Mycobacterium Infections, Nontuberculous/diagnosis , Mycobacterium Infections, Nontuberculous/drug therapy , Mycobacterium Infections, Nontuberculous/microbiology , Nontuberculous Mycobacteria/genetics , Porifera/microbiology , Psoriasis/complications , Receptors, Tumor Necrosis Factor/administration & dosage , Receptors, Tumor Necrosis Factor/therapeutic use , Species Specificity , Triamcinolone/administration & dosage , Triamcinolone/therapeutic use , Tuberculin Test , Ustekinumab
10.
J Cutan Pathol ; 39(6): 626-30, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22524588

ABSTRACT

Primary cutaneous neuroendocrine carcinoma, also known as Merkel cell carcinoma (MCC), usually presents as a dermal and/or subcutaneous tumor. Rarely, it is confined to the epidermis or adnexal epithelium [MCC in situ (MCCIS)]. Little is known about the spectrum of features and biology of MCCIS. Herein, we report a case of MCCIS arising on the cheek of a 77-year-old Caucasian male, which was associated with squamous cell carcinoma in situ. The tumor cells of both the neuroendocrine and squamous components prominently involved adnexal structures but did not invade the dermis. The tumor cells with neuroendocrine features were immunoreactive for cytokeratin-20, chromogranin and synaptophysin. They also expressed p53 but were non-reactive with the monoclonal antibody CM2B4. Lack of labeling for CM2B4 is in keeping with prior observations of combined squamous and MCC. Our findings support the concept of a distinct subtype of virus-independent cutaneous neuroendocrine carcinoma that differs from conventional MCC. The observed overexpression of p53 suggests that the development of this tumor type may be related to chronic ultraviolet damage.


Subject(s)
Carcinoma, Merkel Cell , Carcinoma, Squamous Cell , Gene Expression Regulation, Neoplastic , Neoplasms, Second Primary , Skin Neoplasms , Tumor Suppressor Protein p53/biosynthesis , Aged , Antibodies, Monoclonal/chemistry , Antibodies, Neoplasm/chemistry , Carcinoma, Merkel Cell/metabolism , Carcinoma, Merkel Cell/pathology , Carcinoma, Squamous Cell/metabolism , Carcinoma, Squamous Cell/pathology , Humans , Immunohistochemistry , Male , Neoplasms, Second Primary/metabolism , Neoplasms, Second Primary/pathology , Skin Neoplasms/metabolism , Skin Neoplasms/pathology
11.
Cancer ; 118(20): 5078-83, 2012 Oct 15.
Article in English | MEDLINE | ID: mdl-22437824

ABSTRACT

BACKGROUND: Dermatologic adverse events stemming from anticancer therapies have become an increasingly frequent clinical problem. Inhibitors of mammalian target of rapamycin (mTOR), such as temsirolimus and everolimus, have been associated with a high rate of skin eruptions, but their clinical and histopathologic characteristics have not been explored. METHODS: A retrospective analysis of patients who were referred to the Dermatology Service for diagnosis and management of rash in the setting of therapy with the mTOR inhibitors everolimus and temsirolimus was performed. The parameters that were studied included the time to onset, clinical presentation at the time of dermatologic evaluation, associated symptoms, evolution, results of microbiologic studies, concomitant medications, the need for dose reduction and/or treatment interruption because of rash, and routine histopathology. RESULTS: In total, 13 patients were analyzed. Most rashes were mild (grade 1; 31%) and moderate (grade 2; 54%) in severity, and grade 3 rashes were observed only in 2 patients (15%). The trunk was the most frequently affected region (77%), with the scalp (23%), face (38%), neck (54%), and extremities (69%) also commonly involved. Erythematous papules and pustules constituted the predominant primary lesion morphology (62%). No unique or uniform histopathologic reaction pattern was observed. The most common reaction pattern was that of a mixed, spongiotic interface and perivascular dermatitis, which was observed in 7 of 11 patients (63%). CONCLUSIONS: Although mTOR inhibitors may commonly induce erythematous papules and pustules, they are associated with a spectrum of lesion morphologies and a variety of histopathologic findings. Further clinicohistologic correlation studies are needed.


Subject(s)
Antineoplastic Agents/adverse effects , Exanthema/chemically induced , Sirolimus/analogs & derivatives , TOR Serine-Threonine Kinases/antagonists & inhibitors , Adult , Aged , Everolimus , Exanthema/pathology , Female , Humans , Male , Middle Aged , Sirolimus/adverse effects
12.
Adv Anat Pathol ; 18(6): 450-3, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21993271

ABSTRACT

This review discusses the evolution of an emerging dermatologic entity, virus-associated trichodysplasia spinulosa (TS), and its association with the novel human TS polyomavirus. We will describe how this distinct dermatologic diagnosis has arisen from the convergence of strikingly similar histopathologic findings observed across several case reports. The case of virus-associated TS exemplifies how a combination of astute clinicopathologic observation and a well-designed molecular genetic approach can provide insights into the pathogenesis of cutaneous disease.


Subject(s)
Hair Diseases/pathology , Polyomavirus Infections/pathology , Polyomavirus , Skin Diseases/pathology , Tumor Virus Infections/pathology , Hair Follicle/virology , Humans , Immunocompromised Host , Keratosis/virology , Transplants/adverse effects
13.
J Am Acad Dermatol ; 65(4): 722-725.e2, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21658797

ABSTRACT

BACKGROUND: Dermatologists at the University of California, San Francisco recently reported two patients in the online Journal of the American Academy of Dermatology with purpura presumably induced by levamisole in contaminated cocaine. Levamisole-induced vasculitis and neutropenia has been reported elsewhere in the United States and Canada. Up to 70% of cocaine in the United States could be contaminated. OBJECTIVE: We sought to describe similar cases of vasculitis associated with cocaine use. METHODS: This is a retrospective case series. RESULTS: We report 6 remarkably similar patients seen over just the past few months with retiform purpura on the body and tender purpuric eruptions, necrosis, and eschars of the ears after cocaine use in New York and California. All of these patients had positive perinuclear antineutrophil cytoplasmic antibody values and 3 of the 6 also had an associated neutropenia. Direct immunofluorescence studies suggested an immune complex-mediated vasculitis. LIMITATIONS: This case series is descriptive in nature and, because testing is not easily performed, we did not test for levamisole in the serum or blood to prove this is the causative agent. CONCLUSION: It appears the use of cocaine is associated with the peculiar clinical findings of ear purpura, retiform purpura of the trunk, and neutropenia. We believe this case series may represent the tip of the iceberg as a looming public health problem caused by levamisole. Although the direct causal relationship may be difficult to establish, the astute dermatologist or primary care physician should be able to recognize the characteristic skin lesions and should be wary of the potential development of agranulocytosis.


Subject(s)
Cocaine/adverse effects , Ear, External/drug effects , Levamisole/adverse effects , Neutropenia/chemically induced , Purpura/chemically induced , Vasculitis/chemically induced , Adult , Agranulocytosis/chemically induced , Cocaine-Related Disorders/complications , Drug Contamination , Female , Humans , Male , Middle Aged , Public Health
14.
J Cutan Pathol ; 38(1): 43-8, 2011 Jan.
Article in English | MEDLINE | ID: mdl-20726933

ABSTRACT

Multicentric reticulohistiocytosis (MR) is a rare non-Langerhans histiocytosis that is characterized by cutaneous nodules and severe destructive arthritis. Although 25-30% of reported cases have been associated with internal malignancies, the pathophysiology of MR is unknown. Herein, we report two cases of MR that were associated with urologic neoplasms. Because the tumor suppressor gene p53 may play a role in the biology of other histiocytoses, we investigated its p53 immunoexpression in these two cases. Both cases were positive immunohistochemically, but it remains to be seen whether this finding is truly important in the pathogenesis of MR associated with underlying visceral neoplasms.


Subject(s)
Histiocytosis, Non-Langerhans-Cell/pathology , Paraneoplastic Syndromes/pathology , Urologic Neoplasms/complications , Carcinoma, Neuroendocrine/complications , Carcinoma, Renal Cell/pathology , Carcinoma, Small Cell/complications , Female , Histiocytosis, Non-Langerhans-Cell/etiology , Histiocytosis, Non-Langerhans-Cell/genetics , Humans , Immunohistochemistry , Kidney Neoplasms/complications , Male , Middle Aged , Paraneoplastic Syndromes/etiology , Paraneoplastic Syndromes/genetics , Tumor Suppressor Protein p53/biosynthesis , Tumor Suppressor Protein p53/genetics , Urinary Bladder Neoplasms/complications
17.
Biol Blood Marrow Transplant ; 13(7): 790-805, 2007 Jul.
Article in English | MEDLINE | ID: mdl-17580257

ABSTRACT

The development of nonmyeloablative (NM) hematopoietic cell transplantation (HCT) has extended the potential curative treatment option of allografting to patients in whom it was previously contraindicated because of advanced age or comorbidity. Acute and chronic graft versus host disease (GVHD) and its consequent nonrelapse mortality (NRM), remains the major limitation of NM HCT. In this report, we analyzed the outcome of 67 patients (median age, 45 years) with hematologic diseases receiving NM conditioning with fludarabine 90 mg/m(2) and total body irradiation (TBI) 200-cGy, followed by filgrastim-mobilized peripheral blood stem cell transplant from HLA identical (n = 61), 5/6 antigen-matched related (n = 1), 6/6 antigen-matched unrelated (n = 3), and 5/6 antigen-matched unrelated (n = 2) donors. The first cohort of 21 patients were given cyclosporine (CSP) and mycophenolate mofetil (MMF) as postgrafting immunosuppression, whereas the subsequent cohort was given additional methotrexate (MTX) and extended duration of CSP/MMF prophylaxis in an attempt to reduce graft-versus-host disease (GVHD). Sixty-four (95%) patients engrafted and 3 (5%) had secondary graft failure. Myelosuppression was moderate with neutrophil counts not declining below 500/microL in approximately 25% of patients, and with more than half of the patients not requiring any blood or platelet transfusion. The 2-year cumulative interval (CI) of grade II-IV, grade III-IV acute GVHD and chronic GVHD were 49%, 30%, and 34%, respectively. The 2-year probability of NRM, overall (OS), and progression-free (PFS) survival were 27%, 43%, and 28%, respectively. GVHD-related death accounted for 85% of NRM. Compared with patients receiving CSP/MMF, patients receiving extended duration of CSP/MMF with additional MTX in postgrafting immunosuppression had a significantly lower risk of grade III-IV acute GVHD (CI 20% versus 52%; P = .009) and NRM (CI at 2 years: 11% versus 62%; P < .001), without any significant adverse impact on the risk of relapse (CI at 2 years: 59% versus 33%; P = .174) Subgroup analysis of a cohort of patients given MTX/CSP/MMF showed that patients with "standard risk" diseases (n = 21) had a 3-year OS and PFS of 85% and 65%, respectively. This compares favorably to the 41% (P = .02) and 23% (P = .03) OS and PFS, respectively, in patients with "high-risk" diseases (n = 25). In conclusion, the addition of MTX onto the current postgrafting immunosuppression regimen with extended CSP/MMF prophylaxis duration provides more effective protection against severe GVHD, and is associated with more favorable outcome in patients receiving NM fludarabine/TBI conditioning than in patients receiving fludarabine/TBI conditioning with CSP and MMF without MTX.


Subject(s)
Antineoplastic Agents/administration & dosage , Hematologic Neoplasms/mortality , Hematopoietic Stem Cell Transplantation , Peripheral Blood Stem Cell Transplantation , Transplantation Conditioning , Vidarabine/analogs & derivatives , Adolescent , Adult , Disease-Free Survival , Female , Hematologic Neoplasms/therapy , Humans , Immunosuppression Therapy/mortality , Immunosuppressive Agents/administration & dosage , Immunosuppressive Agents/adverse effects , Male , Middle Aged , Retrospective Studies , Survival Rate , Transplantation, Homologous , Vidarabine/administration & dosage , Whole-Body Irradiation
18.
J Immunol ; 177(3): 1864-71, 2006 Aug 01.
Article in English | MEDLINE | ID: mdl-16849498

ABSTRACT

A key target of many intracellular pathogens is the macrophage. Although macrophages can generate antimicrobial activity, neutrophils have been shown to have a key role in host defense, presumably by their preformed granules containing antimicrobial agents. Yet the mechanism by which neutrophils can mediate antimicrobial activity against intracellular pathogens such as Mycobacterium tuberculosis has been a long-standing enigma. We demonstrate that apoptotic neutrophils and purified granules inhibit the growth of extracellular mycobacteria. Phagocytosis of apoptotic neutrophils by macrophages results in decreased viability of intracellular M. tuberculosis. Concomitant with uptake of apoptotic neutrophils, granule contents traffic to early endosomes, and colocalize with mycobacteria. Uptake of purified granules alone decreased growth of intracellular mycobacteria. Therefore, the transfer of antimicrobial peptides from neutrophils to macrophages provides a cooperative defense strategy between innate immune cells against intracellular pathogens and may complement other pathways that involve delivery of antimicrobial peptides to macrophages.


Subject(s)
Blood Bactericidal Activity/immunology , Cytoplasmic Granules/immunology , Cytoplasmic Granules/microbiology , Intracellular Fluid/immunology , Macrophages, Alveolar/immunology , Mycobacterium tuberculosis/immunology , Neutrophils/immunology , Phagocytosis/immunology , Apoptosis/immunology , Biomarkers/analysis , Cytoplasmic Granules/chemistry , Endosomes/immunology , Endosomes/microbiology , Extracellular Space/immunology , Extracellular Space/microbiology , Growth Inhibitors/chemistry , Growth Inhibitors/isolation & purification , Growth Inhibitors/physiology , Humans , Intracellular Fluid/microbiology , Macrophages, Alveolar/cytology , Macrophages, Alveolar/microbiology , Mycobacterium tuberculosis/growth & development , Mycobacterium tuberculosis/pathogenicity , Neutrophils/chemistry , Neutrophils/microbiology , Phagosomes/immunology , Phagosomes/microbiology , alpha-Defensins/analysis
19.
Science ; 311(5768): 1770-3, 2006 Mar 24.
Article in English | MEDLINE | ID: mdl-16497887

ABSTRACT

In innate immune responses, activation of Toll-like receptors (TLRs) triggers direct antimicrobial activity against intracellular bacteria, which in murine, but not human, monocytes and macrophages is mediated principally by nitric oxide. We report here that TLR activation of human macrophages up-regulated expression of the vitamin D receptor and the vitamin D-1-hydroxylase genes, leading to induction of the antimicrobial peptide cathelicidin and killing of intracellular Mycobacterium tuberculosis. We also observed that sera from African-American individuals, known to have increased susceptibility to tuberculosis, had low 25-hydroxyvitamin D and were inefficient in supporting cathelicidin messenger RNA induction. These data support a link between TLRs and vitamin D-mediated innate immunity and suggest that differences in ability of human populations to produce vitamin D may contribute to susceptibility to microbial infection.


Subject(s)
Antimicrobial Cationic Peptides/genetics , Calcitriol/metabolism , Immunity, Innate , Macrophages/physiology , Monocytes/physiology , Mycobacterium tuberculosis/growth & development , Toll-Like Receptors/physiology , 25-Hydroxyvitamin D3 1-alpha-Hydroxylase/genetics , Black or African American , Antimicrobial Cationic Peptides/biosynthesis , Antimicrobial Cationic Peptides/metabolism , Calcitriol/blood , Cathelicidins , Colony Count, Microbial , Dendritic Cells/microbiology , Dendritic Cells/physiology , Disease Susceptibility , Humans , Macrophages/immunology , Macrophages/microbiology , Monocytes/microbiology , Oligonucleotide Array Sequence Analysis , RNA, Messenger/genetics , RNA, Messenger/metabolism , Receptors, Calcitriol/genetics , Steroid Hydroxylases/genetics , Tuberculosis/etiology , Tuberculosis/immunology , Up-Regulation , Vitamin D3 24-Hydroxylase
20.
Nat Med ; 11(6): 653-60, 2005 Jun.
Article in English | MEDLINE | ID: mdl-15880118

ABSTRACT

Leprosy enables investigation of mechanisms by which the innate immune system contributes to host defense against infection, because in one form, the disease progresses, and in the other, the infection is limited. We report that Toll-like receptor (TLR) activation of human monocytes induces rapid differentiation into two distinct subsets: DC-SIGN+ CD16+ macrophages and CD1b+ DC-SIGN- dendritic cells. DC-SIGN+ phagocytic macrophages were expanded by TLR-mediated upregulation of interleukin (IL)-15 and IL-15 receptor. CD1b+ dendritic cells were expanded by TLR-mediated upregulation of granulocyte-macrophage colony-stimulating factor (GM-CSF) and its receptor, promoted T cell activation and secreted proinflammatory cytokines. Whereas DC-SIGN+ macrophages were detected in lesions and after TLR activation in all leprosy patients, CD1b+ dendritic cells were not detected in lesions or after TLR activation of peripheral monocytes in individuals with the progressive lepromatous form, except during reversal reactions in which bacilli were cleared by T helper type 1 (TH1) responses. In tuberculoid lepromatous lesions, DC-SIGN+ cells were positive for macrophage markers, but negative for dendritic cell markers. Thus, TLR-induced differentiation of monocytes into either macrophages or dendritic cells seems to crucially influence effective host defenses in human infectious disease.


Subject(s)
Cell Differentiation/physiology , Dendritic Cells/physiology , Macrophages/physiology , Membrane Glycoproteins/physiology , Monocytes/physiology , Receptors, Cell Surface/physiology , Antigens, CD1/metabolism , Cell Adhesion Molecules/metabolism , Gene Expression , Humans , Immunity, Innate/physiology , Lectins, C-Type/metabolism , Leprosy/immunology , Lymphocyte Activation , Receptors, Cell Surface/metabolism , T-Lymphocytes/physiology , Toll-Like Receptors
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