COX-2 inhibition reduces Brucella bacterial burden in draining lymph nodes

International audienceBrucella is a Gram-negative facultative intracellular bacterium responsible for a chronic disease known as brucellosis, the most widespread re-emerging zoonosis worldwide. Establishment of a Th1-mediated immune response characterized by the production of IL-12 and IFN gamma is essential to control the disease. Leukotrienes derived from arachidonic acid (AA) metabolism are known to negatively regulate a protective Th1 immune response against bacterial infections. Here, using genomics approaches we demonstrate that Brucella abortus strongly stimulates the prostaglandin (PG) pathway in dendritic cells (DC). We also show an induction of AA production by infected cells. This correlates with the expression of Ptgs2, a gene encoding the downstream cyclooxygenase-2 (COX-2) enzyme in infected DC. By comparing different infection routes (oral, intradermal, intranasal and conjunctival), we identified the intradermal inoculation route as the more potent in inducing Ptgs2 expression but also in inducing a local inflammatory response in the draining cervical lymph nodes (CLN). NS-398, a specific inhibitor of COX-2 enzymatic activity decreased B. melitensis burden in the CLN after intradermal infection. This effect was accompanied by a decrease of II10 and a concomitant increase of Ifng expression. Altogether, these results suggest that Brucella has evolved to take advantage of the PG pathway in the harsh environment of the CLN in order to persist and subvert immune responses. This work also proposes that novel strategies to control brucellosis may include the use of COX-2 inhibitors

Whipple's Disease: a Macrophage Disease

International audienc

The immune reconstitution inflammatory syndrome in whipple disease: a cohort study.

Whipple disease, which is caused by infection with Tropheryma whipplei, can be treated effectively with antimicrobials. Occasionally, inflammation reappears after initial improvement; this is often interpreted as refractory or recurrent disease. However, polymerase chain reaction for T. whipplei in tissue is sometimes negative during reinflammation, indicating absence of vital bacteria, and this reinflammation does not respond to antimicrobials but does respond to steroids.To demonstrate that the immune reconstitution inflammatory syndrome (IRIS) occurs in patients treated for Whipple disease.Cohort study. (International Standard Randomised Controlled Trial Number Register registration number: ISRCTN45658456)2 academic medical centers in Germany.142 patients treated for Whipple disease out of a cohort of 187 were observed for reappearance of inflammatory signs after effective antibiotic therapy. Definitions of IRIS in HIV infection, tuberculosis, and leprosy were adapted for application to Whipple disease.On the basis of study definitions, IRIS was diagnosed in 15 of 142 patients. Symptoms included fever, arthritis, pleurisy, erythema nodosum, inflammatory orbitopathy, small-bowel perforation, and a hypothalamic syndrome. Two patients died. There was a positive correlation with previous immunosuppressive treatment and a negative correlation with previous diarrhea and weight loss.The study was observational and thus has inherent weaknesses, such as incomplete and potentially selective data recording.The immune reconstitution inflammatory syndrome was diagnosed in about 10\% of patients with Whipple disease in the study cohort; the outcome varied from mild to fatal. Patients who had had previous immunosuppressive therapy were at particular risk. An immune reconstitution syndrome should be considered in patients with Whipple disease in whom inflammatory symptoms recur after effective treatment. Early diagnosis and treatment with steroids may be beneficial; prospective studies are needed.European Commission and Deutsche Forschungsgemeinschaft

Immunregulation, intestinale Barrierestörung und mikrobielle Translokation beim Morbus Whipple

Einführung: Der klassische Morbus Whipple (M. Whipple) ist eine systemische, chronische Infektion verursacht durch das Bakterium Tropheryma whipplei (T. whipplei). Charakteristische Symptommanifestation ist der Gastrointestinaltrakt mit chronischer Diarrhoe und Zeichen der Malabsorption. Eine Makrophagenakkumulation in der Lamina propria, welche große Mengen an Periodic acid-Schiff (PAS)-positiven Partikeln enthalten, ist pathognomonisch für den klassischen M. Whipple. Während die mukosale Immunreaktion durch ein tolerogenes Milieu charakterisiert ist, welche verschiedenen immunologischen Defiziten der Patienten sowie anti-inflammatorischer Effekte von T. whipplei selbst zugeschrieben werden, ist die Rolle regulatorischer T-Zellen (Tregs), die immunologische Grundlage des entzündlichen Immunrekonstitutionssyndroms (IRIS) sowie die Ursache der systemischen Entzündungsreaktion bisher nicht aufgeklärt. Außerdem galt es zu untersuchen inwieweit die mukosale Infektion beim M. Whipple mit den zu beobachtenden gastrointestinalen Symptomen verbunden ist. Methoden: Dünndarmproben wurden mittels Zangenbiopsie im Rahmen der Routineösophagogastroduodenoskopie entnommen. Die Biopsien wurden umgehend für elektrophysiologische Experimente in Ussing-Kammern und Analyse der Zytokinproduktion präpariert, oder nach einer Fixierung und Paraffineinbettung für immunhistochemische und strukturelle Analysen verwandt. Die Detektion der Tight junction-Proteinexpression erfolgte durch Westernblotanalyse. Surrogatmarker einer mikrobiellen Translokation (MT) sowie entzündlichen Reaktion wurden im peripheren Blut gemessen. Die Phänotypisierung und Funktionsanalyse von zirkulierenden Immunzellen geschah mittels Durchflusszytometrie. Resultate: Wir konnten eine erhöhte Anzahl von mukosalen Tregs und assoziierter Zytokine nachweisen. Zirkulierende Tregs wiesen darüber hinaus einen aktivierten Phänotyp auf, der eine T-Zell-Anergie vermitteln kann. Die verminderte gegenregulative Kapazität durch Tregs war außerdem mit einer unspezifischen Aktivierung und Expansion von CD4+ T-Zellen beim IRIS assoziiert. Eine hyperregenerative mukosale Transformation, ging mit einem Verlust des differenzierten Oberflächenepithels und nachfolgend mit einer erhöhten Permeabilität für osmotisch aktive Elektrolyte und Makromoleküle einher. Die duodenale Architektur- und Permeabilitätsstörung zeigte sich unter antibiotischer Therapie rückläufig. Das strukturelle Korrelat für die beobachtete Barrierestörung bildete eine veränderte Expression der transmembranalen Proteine Claudin-1, Claudin-2, Claudin-3 und Tricellulin. Die biologische Signifikanz der mukosalen Barrierestörung wurde durch den Nachweis erhöhter Serummarker einer MT, welche unter antibiotische Therapie wieder rückläufig waren, unterstrichen. Schlussfolgerung: Tregs könnten zur chronischen Infektion und systemischen Ausbreitung von T. whipplei beitragen und sind außerdem an der T-Zell-Rekonstitution beim IRIS beteiligt. Die mukosale Immunantwort ist verantwortlich für die Barrierestörung beim klassischen M. Whipple. Der Verlust von Absorptionskapazität sowie ein Leckflux von Ionen und Wasser stellen die Ursache der Diarrhoe dar. Eine gesteigerte Permeabilität für Makromoleküle und die nachfolgende vermehrte MT sind ein Mediator der systemischen Entzündungsreaktion. Die mukosale Barriere modulierende Therapien könnten eine symptomatische Strategie bei Patienten mit einem klassischen M. Whipple darstellen.Introduction: Classical Whipple’s disease (CWD) is a chronic disseminated infection caused by Tropheryma whipplei (T. whipplei). Most patients suffer from gastrointestinal symptoms such as chronic diarrhea and malabsorption. CWD is characterized by accumulation of small intestinal mucosal macrophages, which are densely packed with periodic acid–Schiff (PAS)-stained granules corresponding to intracellular bacteria. Although the tolerogenic mucosal immune reaction was attributed to a subtle immune defect of the host and to anti-inflammatory effects of T. whipplei, little is known about the role of regulatory T cells (Tregs), the immunological processes underlying immune reconstitution inflammatory syndrome (IRIS) and the causes of systemic inflammation in CWD. Further, the question how the mucosal infection in CWD is linked to the gastrointestinal symptoms of the patients is unresolved. Methods: Duodenal mucosa specimens were obtained by forceps biopsy during routine upper gastroduodenal endoscopy. Biopsies were immediately processed to electrophysiological experiments in Ussing-type chambers or analysis of cytokine production or fixed and embedded in paraffin for immunohistochemical and structural analysis. For detection of tight junction protein expression western blot analysis was performed. Surrogate markers of microbial translocation (MT) and inflammation were measured in peripheral blood samples. Immune cells were characterized and functionally analyzed by flow cytometry. Results: The numbers of mucosal Tregs and related cytokines was found to be increased. Further, peripheral Tregs exhibit a more activated phenotype that facilitates exhaustion of effector CD4+ T cells. A nonspecific activation and expansion CD4+ T cells that are not sufficiently counterbalanced by Tregs mediates IRIS in CWD. Our data indicate a hyperregenerative small intestinal mucosal transformation with loss of differentiated surface epithelium subsequently increasing duodenal permeability to small osmotically active solutes and macromolecules. Duodenal architecture and permeability ameliorated upon antibiotic treatment. Structural correlates for these alterations were concordant changes of membranous claudin-1, claudin-2, claudin-3, and tricellulin expression. Increased serum markers of MT and their decline following treatment corroborated the biological significance of the mucosal barrier defect. Conclusion: Tregs might contribute to the chronic infection and systemic spread of T. whipplei in CWD and during T cell reconstitution in CWD IRIS they reveal insufficient regulative capacity. Furthermore, the mucosal immune responses in CWD elicit barrier dysfunction. Diarrhea is caused by loss of absorptive capacity and leak flux of ions and water. Increased permeability to macromolecules and subsequent MT contributes to systemic inflammation. Thus, therapeutic strategies to reconstitute the mucosal barrier and control inflammation could assist symptomatic control of CWD

Mechanisms Underlying HIV Associated Non-infectious Lung Disease

Pulmonary disease remains a primary source of morbidity and mortality in persons living with HIV (PLWH), although the advent of potent combination antiretroviral therapy has resulted in a shift from predominantly infectious to noninfectious pulmonary complications. PLWH are at high risk for COPD, pulmonary hypertension, and lung cancer even in the era of combination antiretroviral therapy. The underlying mechanisms of this are incompletely understood, but recent research in both human and animal models suggests that oxidative stress, expression of matrix metalloproteinases, and genetic instability may result in lung damage, which predisposes PLWH to these conditions. Some of the factors that drive these processes include tobacco and other substance use, direct HIV infection and expression of specific HIV proteins, inflammation, and shifts in the microbiome toward pathogenic and opportunistic organisms. Further studies are needed to understand the relative importance of these factors to the development of lung disease in PLWH

Rapidly progressive dementia and intractable diarrhea: a teaching case report and a systematic review of cognitive impairment in Whipple's disease

Objective Whipple's disease (WD) is a systemic, chronic, relapsing disease caused by Tropheryma whipplei, which can mimic signs and symptoms of various clinical entities. Typical manifestations are represented by gastrointestinal and systemic symptoms, among which neurological ones are frequent. We present the case of a patient with WD and rapidly progressive cognitive impairment and a review of literature aimed to report epidemiological, clinical, neuroimaging, and laboratory findings of cognitive impairment associated with WD.Methods A systematic review of medical literature published until November 22, 2020, was performed. Full-text, peer-reviewed case reports and series in English language presenting patients with WD and cognitive impairment were included. Data concerning demographic, clinical, neuroimaging, and laboratory characteristics were collected and synthesized qualitatively.Results The patient was a 54-year-old male who developed rapidly progressive dementia, fluctuating arousal disturbances, and supranuclear ophthalmoparesis associated with chronic diarrhea and fever spikes. T. whipplei was detected in the cerebrospinal fluid, and appropriate antimicrobial therapy was given with progressive clinical benefit. The systematic review of 114 case reports/series identified 147 patients with WD and cognitive impairment; this latter was rarely isolated. Neurological symptoms associated with cognitive decline were psychiatric disturbances, supranuclear ophthalmoplegia, hypothalamic involvement, and consciousness disorders. Brain imaging and cerebrospinal fluid findings were heterogeneous and nonspecific.Conclusions Cognitive impairment represents one of the most common neurological features associated with WD. The clinical suspicion of this disease in patients with rapidly progressive dementia is crucial to guide diagnostic strategies and proper antimicrobial therapy, which may revert the clinical deterioration

The correlation between HTLV-1 and Whipple's disease in a Japanese population: A case series

Purpose: Whippleʼs disease (WD) is a rare systemic disease caused by Tropheryma whipplei. It is predominantly diagnosed in middle-aged Caucasian men, and its association with immunosuppression and human leukocyte antigen (HLA)-B27 has been discussed; however, these studies are limited to western countries. Herein, we analyzed five WD cases and eight previously described WD cases in the Japanese population. Results: None of the patients were under immunosuppressive treatment or HLA-B27-positive. In 10/13 cases checking anti-HTLV-1 antibody, 6/10 (60%) cases were carriers of human T-cell leukemia virus type 1 (HTLV-1). All patients were treated with antibiotics, and their symptoms diminished promptly. The prognosis for these cases was excellent, and one patient developed the smoldering type adult T-cell leukemia/lymphoma, but no progression to aggressive type adult T-cell leukemia/lymphoma was observed. Conclusion: These findings probably support the findings that the immunosuppressive effect of HTLV-1 triggers WD in Japanese patients. It is recommended to evaluate the presence of HTLV-1 antibody in the blood of WD patients in HTLV-1 endemic areas for the clarification of the accurate pathogenesis and appropriate clinical follow-up. Ryukyu Med. J., 42 (1～4) 21～28, 2023http://purl.org/coar/resource_type/c_650

Whipple`s disease - clinical spectrum and diagnostic approach (with a contribution of eight cases)

PURPOSE: Whipple`s disease (WD) is a rare systemic infection caused by the bacterium Tropheryma whipplei. Since the clinical features of the disease are non-specific, diagnosis still remains a challenge. The aim of the study is to analyse the clinical presentation and diagnostic approach in patients with WD.MATERIAL AND METHODS: Eight patients, six females and two males at an average age of 59 years (range, 46-79 years) were diagnosed with WD from January, 2012 to May, 2013 in the Clinic of Hepatogastroenterology, St. Marina University Hospital of Varna. Laboratory tests, endoscopic, radiologic, ultrasound and histomorphological examinations were performed.RESULTS: The main symptoms are abdominal pain, chronic diarrhoea and meteorism. Only one female patient presents with clinical signs of malabsorbtion, such as weight loss, anasarca, ascites, pleural effusions and anaemia. There are no extraintestinal manifestations. Tests for Chlamydia trachomatis, tuberculosis and Clostridium difficile are negative. Stool examination does not show any parasitic or bacterial infection. Coeliac disease (CD) serological tests are negative, except in one female with co-existing gluten enteropathy since childhood onwards, where Crohn colitis is diagnosed, too. Endoscopy demonstrates mild to moderate atrophy of the intestinal mucosa. Histological examination establishes mild villous atrophy, lymphoplasmatic infiltration and lymph vessel dilation. All the biopsies show PAS-positive inclusions in the macrophages. Doxycycline therapy exerts a favourable effect on the clinical symptoms in all the patients.CONCLUSION: Whipple`s disease (WD) is a rare systemic disease that is commonly late or falsely diagnosed. The prognosis of non-treated patients is poor. The disease should be considered in any patients with prolonged gastrointestinal symptoms such as unexplained abdominal pain, diarrhoea and features of malabsorption syndrome. The appropriate antibiotic treatment achieves remission and improves the patient's quality of life.Keywords: Whipple disease, diagnosis, histology, malabsorption, treatmen

Tropheryma whipplei

Purpose. To report a case of Tropheryma whipplei infection with crystalline keratopathy and review the recent literature on the presentation, diagnosis, and management of Whipple's disease. Methods. Detailed case presentation and extensive literature search of Pubmed for all years through February 2012 using the following search terms: Whipple's disease, Tropheryma whipplei, corneal deposits, crystalline keratopathy, and uveitis. Relevant articles were retrieved and analyzed. English abstracts were used for non-English articles. Cross-referencing was employed and reference lists from selected articles were used to identify additional pertinent articles. Results. Diagnosis of Whipple's disease remains challenging and untreated infection can result in mortality. Ocular signs and symptoms are usually nonspecific, but several independent cases have reported the presence of intraocular crystals or crystalline-like deposits. Conclusions. The presence of intraocular crystals or crystalline-like deposits may be an identifying feature of ocular Whipple's disease