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Slavik T, Lauwers GY. Navigating the jungles of tropical infectious gastrointestinal pathology: a pattern-based approach to the endoscopic biopsy. Virchows Arch 2018; 472:135-147. [PMID: 28589386 PMCID: PMC7087759 DOI: 10.1007/s00428-017-2166-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 05/17/2017] [Accepted: 05/30/2017] [Indexed: 12/22/2022]
Abstract
International travels and global human migration have had the unforeseen consequence of increasing the exposure of histopathologists in developed countries to the pathology of tropical infectious disease. The gastrointestinal tract (GIT) is often the primary site of infection due to the faecal-oral route of transmission and the high risk of exposure to contaminated water, food or soil when travelling to these regions. Whilst current microbiologic techniques are far more sensitive than histology in detecting infectious pathogens, the histopathologist nonetheless retains a pivotal role in diagnosing tropical GIT disease. This role entails evaluating endoscopic biopsies for any characteristic inflammatory pattern, identifying pathogens which may be present and excluding other look-alike pathologies. Recent advances in commercially available diagnostic modalities, including molecular techniques, have further broadened the scope of the histopathologist's armamentarium. This review outlines a practical pattern-based approach to diagnosing tropical GIT infections in endoscopic material, so as to assist pathologists less familiar with this spectrum of pathology.
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Affiliation(s)
- Tomas Slavik
- Ampath Pathology Laboratories, Pretoria, South Africa.
- Department of Anatomical Pathology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.
- , Private Bag X9, Highveld Park, Centurion, Pretoria, 0067, South Africa.
| | - Gregory Y Lauwers
- Department of Anatomic Pathology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL, USA
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Abstract
The importance of mycobacteria as opportunistic pathogens, particularly members of the M. avium complex (MAC), in patients with progressive HIV infection was recognized early in the AIDS epidemic. It took longer to appreciate the global impact and devastation that would result from the deadly synergy that exists between HIV and M. tuberculosis. This HIV/M. tuberculosis co-pandemic is ongoing and claiming millions of lives every year. In addition to MAC, a number of other non-tuberculous mycobacteria have been recognized as opportunistic pathogens in HIV-infected individuals; some of these are more commonly encountered (e.g., M. kansasii) than others (M. haemophilum and M. genevense). Finally, there are challenges to concomitantly treating the HIV and the infecting Mycobacterium species, because of antimicrobial resistance, therapeutic side-effects and the complex pharmacologic interactions of the antiretroviral and antimycobacterial multidrug therapy.
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Affiliation(s)
- Gary W Procop
- Staff, Pathology and Clinical Microbiology, Cleveland Clinic, 9500 Euclid Avenue/LL2-2, Cleveland, OH 44195, United States.
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Cassol E, Rossouw T, Malfeld S, Mahasha P, Slavik T, Seebregts C, Bond R, du Plessis J, Janssen C, Roskams T, Nevens F, Alfano M, Poli G, van der Merwe SW. CD14(+) macrophages that accumulate in the colon of African AIDS patients express pro-inflammatory cytokines and are responsive to lipopolysaccharide. BMC Infect Dis 2015; 15:430. [PMID: 26475133 PMCID: PMC4609115 DOI: 10.1186/s12879-015-1176-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 10/05/2015] [Indexed: 01/05/2023] Open
Abstract
Background Intestinal macrophages are key regulators of inflammatory responses to the gut microbiome and play a central role in maintaining tissue homeostasis and epithelial integrity. However, little is known about the role of these cells in HIV infection, a disease fuelled by intestinal inflammation, a loss of epithelial barrier function and increased microbial translocation (MT). Methods Phenotypic and functional characterization of intestinal macrophages was performed for 23 African AIDS patients with chronic diarrhea and/or weight loss and 11 HIV-negative Africans with and without inflammatory bowel disease (IBD). AIDS patients were treated with cotrimoxazole for the prevention of opportunistic infections (OIs). Macrophage phenotype was assessed by flow cytometry and immuno-histochemistry (IHC); production of proinflammatory mediators by IHC and Qiagen PCR Arrays; in vitro secretion of cytokines by the Bio-Plex Suspension Array System. Statistical analyses were performed using Spearman’s correlation and Wilcoxon matched-pair tests. Results between groups were analyzed using the Kruskal-Wallis with Dunn’s post-test and the Mann–Whitney U tests. Results None of the study participants had evidence of enteric co-infections as assessed by stool analysis and histology. Compared to healthy HIV-negative controls, the colon of AIDS patients was highly inflamed with increased infiltration of inflammatory cells and increased mRNA expression of proinflammatory cytokine (tumour necrosis factor (TNF)-α, interleukin (IL)-1β, IFN-γ, and IL-18), chemokines (chemokine (C-C motif) ligand (CCL)2 and chemokine (C-X-C) motif ligand (CXCL)10) and transcription factors (TNF receptor-associated factor (TRAF)6 and T-box (TXB)21). IHC revealed significant co-localization of TNF-α and IL-1β with CD68+ cells. As in IBD, HIV was associated with a marked increase in macrophages expressing innate response receptors including CD14, the co-receptor for lipopolysaccharide (LPS). The frequency of CD14+ macrophages correlated positively with plasma LPS, a marker of MT. Total unfractionated mucosal mononuclear cells (MMC) isolated from the colon of AIDS patients, but not MMC depleted of CD14+ cells, secreted increased levels of proinflammatory cytokines ex vivo in response to LPS. Conclusions Intestinal macrophages, in the absence of overt OIs, play an important role in driving persistent inflammation in HIV patients with late-stage disease and diarrhea. These results suggest intensified treatment strategies that target inflammatory processes in intestinal macrophages may be highly beneficial in restoring the epithelial barrier and limiting MT in HIV-infected patients.
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Affiliation(s)
- Edana Cassol
- MRC Unit for Inflammation and Immunity, Department of Immunology and the Tshwane Academic Division of the National Health Laboratory Service, University of Pretoria, Pretoria, South Africa. .,Department of Health Sciences, Carleton University, 5433 Herzberg Laboratories, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada.
| | - Theresa Rossouw
- MRC Unit for Inflammation and Immunity, Department of Immunology and the Tshwane Academic Division of the National Health Laboratory Service, University of Pretoria, Pretoria, South Africa. .,Department of Family Medicine, University of Pretoria, Pretoria, South Africa.
| | - Susan Malfeld
- MRC Unit for Inflammation and Immunity, Department of Immunology and the Tshwane Academic Division of the National Health Laboratory Service, University of Pretoria, Pretoria, South Africa.
| | - Phetole Mahasha
- MRC Unit for Inflammation and Immunity, Department of Immunology and the Tshwane Academic Division of the National Health Laboratory Service, University of Pretoria, Pretoria, South Africa.
| | - Tomas Slavik
- Department of Anatomical Pathology, University of Pretoria and Ampath Pathology Laboratories, Pretoria, South Africa.
| | - Chris Seebregts
- Jembi Health Systems NPC, Durban, South Africa. .,School of Mathematics, Statistics and Computer Science, University of KwaZulu-Natal, Durban, South Africa.
| | - Robert Bond
- Hepatology and GI-Research Laboratory, University of Pretoria, Pretoria, South Africa.
| | - Johannie du Plessis
- Hepatology and GI-Research Laboratory, University of Pretoria, Pretoria, South Africa.
| | - Carl Janssen
- Hepatology and GI-Research Laboratory, University of Pretoria, Pretoria, South Africa.
| | - Tania Roskams
- Translational Cell and Tissue Research, Department of Imaging and Pathology, University of Leuven, Leuven, Belgium.
| | - Frederik Nevens
- Department of Hepatology, University of Leuven, Leuven, Belgium.
| | - Massimo Alfano
- San Raffaele Scientific Institute, School of Medicine, Milan, Italy. .,Present Address: Division of Experimental Oncology/Unit of Urology, URI, IRCCS Ospedale San Raffaele, Milan, Italy.
| | - Guido Poli
- San Raffaele Scientific Institute, School of Medicine, Milan, Italy. .,Vita-Salute San Raffaele University, School of Medicine, Milan, Italy. .,Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, USA.
| | - Schalk W van der Merwe
- MRC Unit for Inflammation and Immunity, Department of Immunology and the Tshwane Academic Division of the National Health Laboratory Service, University of Pretoria, Pretoria, South Africa. .,Department of Internal Medicine, Division of Liver and Biliopancreatic Disorders, University of Leuven, Leuven, Belgium.
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Humanized HLA-DR4 mice fed with the protozoan pathogen of oysters Perkinsus marinus (Dermo) do not develop noticeable pathology but elicit systemic immunity. PLoS One 2014; 9:e87435. [PMID: 24498105 PMCID: PMC3909113 DOI: 10.1371/journal.pone.0087435] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Accepted: 12/23/2013] [Indexed: 12/02/2022] Open
Abstract
Perkinsus marinus (Phylum Perkinsozoa) is a marine protozoan parasite responsible for “Dermo” disease in oysters, which has caused extensive damage to the shellfish industry and estuarine environment. The infection prevalence has been estimated in some areas to be as high as 100%, often causing death of infected oysters within 1–2 years post-infection. Human consumption of the parasites via infected oysters is thus likely to occur, but to our knowledge the effect of oral consumption of P. marinus has not been investigated in humans or other mammals. To address the question we used humanized mice expressing HLA-DR4 molecules and lacking expression of mouse MHC-class II molecules (DR4.EA0) in such a way that CD4 T cell responses are solely restricted by the human HLA-DR4 molecule. The DR4.EA0 mice did not develop diarrhea or any detectable pathology in the gastrointestinal tract or lungs following single or repeated feedings with live P. marinus parasites. Furthermore, lymphocyte populations in the gut associated lymphoid tissue and spleen were unaltered in the parasite-fed mice ruling out local or systemic inflammation. Notably, naïve DR4.EA0 mice had antibodies (IgM and IgG) reacting against P. marinus parasites whereas parasite specific T cell responses were undetectable. Feeding with P. marinus boosted the antibody responses and stimulated specific cellular (IFNγ) immunity to the oyster parasite. Our data indicate the ability of P. marinus parasites to induce systemic immunity in DR4.EA0 mice without causing noticeable pathology, and support rationale grounds for using genetically engineered P. marinus as a new oral vaccine platform to induce systemic immunity against infectious agents.
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