Drug tolerance in replicating mycobacteria mediated by a macrophage-induced efflux mechanism.

Treatment of tuberculosis, a complex granulomatous disease, requires long-term multidrug therapy to overcome tolerance, an epigenetic drug resistance that is widely attributed to nonreplicating bacterial subpopulations. Here, we deploy Mycobacterium marinum-infected zebrafish larvae for in vivo characterization of antitubercular drug activity and tolerance. We describe the existence of multidrug-tolerant organisms that arise within days of infection, are enriched in the replicating intracellular population, and are amplified and disseminated by the tuberculous granuloma. Bacterial efflux pumps that are required for intracellular growth mediate this macrophage-induced tolerance. This tolerant population also develops when Mycobacterium tuberculosis infects cultured macrophages, suggesting that it contributes to the burden of drug tolerance in human tuberculosis. Efflux pump inhibitors like verapamil reduce this tolerance. Thus, the addition of this currently approved drug or more specific efflux pump inhibitors to standard antitubercular therapy should shorten the duration of curative treatment.

Overlap Syndromes in Sarcoidosis: Clinical Features and Outcomes.

Sarcoidosis is a multisystem inflammatory disease characterized by noncaseating granulomatous inflammation. While pulmonary sarcoidosis is most common, extrapulmonary involvement occurs in 50 to 74% of patients and can be the presenting abnormality in some patients. The diagnosis of sarcoidosis is based on a compatible clinical presentation in combination with granulomas on histology and exclusion of other causes. However, the absence of a diagnostic biomarker for sarcoidosis, in addition to the overlap of granulomatous inflammation and nonspecific clinical findings with other diseases, often results in a delayed diagnosis. Sarcoidosis overlap syndromes are typically described when sarcoidosis is diagnosed in the presence of another disease (concurrently or sequentially) with shared clinical and histologic features, or when sarcoidosis presents with clinical features typically observed in, but not diagnostic of, other diseases. Awareness of overlap syndromes is important for clinicians to avoid diagnostic errors and evaluate for concomitant diagnoses that may impact the management and outcome of sarcoidosis. This article is intended to provide an overview of these presentations and the most commonly associated diseases, with attention to their prevalence, clinical features, and reciprocal impacts on disease outcomes.

Decidual Granulomata of Unclear Significance.

Granulomatous inflammation is a histologic finding with a relatively wide variety of causes. In general, considerations include infectious etiologies, autoimmune conditions, or foreign body reactions. Granulomatous inflammation is uncommonly seen in the placenta. We present a unique case of a young woman with preterm labor and rupture of membranes whose placenta demonstrated perivascular decidual granulomata in the membranes and the basal plate.

Revisiting hypoxia therapies for tuberculosis.

The spectre of the coming post-antibiotic age demands novel therapies for infectious diseases. Tuberculosis (TB), caused by Mycobacterium tuberculosis, is the single deadliest infection throughout human history. M. tuberculosis has acquired antibiotic resistance at an alarming rate with some strains reported as being totally drug resistant. Host-directed therapies (HDTs) attempt to overcome the evolution of antibiotic resistance by targeting relatively immutable host processes. Here, I hypothesise the induction of hypoxia via anti-angiogenic therapy will be an efficacious HDT against TB. I argue that anti-angiogenic therapy is a modernisation of industrial revolution era sanatoria treatment for TB, and present a view of the TB granuloma as a 'bacterial tumour' that can be treated with anti-angiogenic therapies to reduce bacterial burden and spare host immunopathology. I suggest two complementary modes of action, induction of bacterial dormancy and activation of host hypoxia-induced factor (HIF)-mediated immunity, and define the experimental tools necessary to test this hypothesis.

Positron Emission Tomography Imaging of Macaques with Tuberculosis Identifies Temporal Changes in Granuloma Glucose Metabolism and Integrin α4ß1-Expressing Immune Cells.

Positron emission tomography and computed tomography imaging (PET/CT) is an increasingly valuable tool for diagnosing tuberculosis (TB). The glucose analog [18F]fluoro-2-deoxy-2-d-glucose ([18F]-FDG) is commonly used in PET/CT that is retained by metabolically active inflammatory cells in granulomas, but lacks specificity for particular cell types. A PET probe that could identify recruitment and differentiation of different cell populations in granulomas would be a useful research tool and could improve TB diagnosis and treatment. We used the Mycobacterium-antigen murine inflammation model and macaques with TB to identify [64Cu]-labeled CB-TE1A1P-PEG4-LLP2A ([64Cu]-LLP2A), a high affinity peptidomimetic ligand for very late Ag-4 (VLA-4; also called integrin α4ß1) binding cells in granulomas, and compared [64Cu]-LLP2A with [18F]-FDG over the course of infection. We found that [64Cu]-LLP2A retention was driven by macrophages and T cells, with less contribution from neutrophils and B cells. In macaques, granulomas had higher [64Cu]-LLP2A uptake than uninfected tissues, and immunohistochemical analysis of granulomas with known [64Cu]-LLP2A uptake identified significant correlations between LLP2A signal and macrophage and T cell numbers. The same cells coexpressed integrin α4 and ß1, further supporting that macrophages and T cells drive [64Cu]-LLP2A avidity in granulomas. Over the course of infection, granulomas and thoracic lymph nodes experienced dynamic changes in affinity for both probes, suggesting metabolic changes and cell differentiation or recruitment occurs throughout granuloma development. These results indicate [64Cu]-LLP2A is a PET probe for VLA-4, which when used in conjunction with [18F]-FDG, may be a useful tool for understanding granuloma biology in TB.

Postinjection abscesses and granulomas in children adopted from Russia.

Up to 1.3 million children from the former Soviet Union (fSU) and Eastern Europe have been placed in institutional care worldwide. With the hope of ensuring the child's health in the immediate post-adoption period, these children are known to receive many injections of vaccines, vitamins, and medications, many unnecessary and often administered with unsafe technique. This practice can lead to formation of suppurative granulomas in these children. Though rare, dermatologists should be aware of these conditions in adoptees from Eastern Europe.

Matrix metalloproteinase-2 and matrix metalloproteinase-9 in mice with ocular toxocariasis.

In ocular toxocariasis, Toxocara canis-induced inflammatory reaction can lead to eye destruction and granuloma, which is formed by immune cell infiltration and concurrent extensive remodeling tissue. Herein, the histomorphology of granuloma and proteinase production in the eye of T. canis-infected BALB/c mice were investigated. Pathological effects substantially increased after the infection culminated in a severe leukocyte infiltration and granuloma formation from days 4 to 56 post-inoculation. The matrix metalloproteinase (MMP)-2 and MMP-9 activities remarkably increased, compared with those of uninfected control, by gelatin zymography and Western blot analysis in ocular toxocariasis. Granuloma formation had a remarkably positive correlation with MMP-2 and MMP-9 levels. We suggested that T. canis larvae and leukocytes infiltrated from blood vessel both migrated into corpus adiposum orbitae. Activated leukocytes secreted MMP-2 and MMP-9, leading to fibronectin degradation. The imbalance of MMP-2/TIMP-2 and MMP-9/TIMP-1 may play a role in inflammatory cell infiltration and extracellular matrix degradation, forming granuloma, in ophthalmological pathogenesis of T. canis infection.

Enfermedad granulomatosa hepática.

Granulomas are circumscribed lesions mainly composed of mononuclear cells that arise in response to poorly degradable antigenic stimuli. They are found in 2-15 % of liver biopsies and the meaning of their finding can range from an incidental phenomenon to the manifestation of a systemic disease of infectious, autoimmune or neoplastic origin. Clinical presentation usually points at the underlying pathology; however, the list of associated conditions is extensive, and differs based on patient epidemiological history and baseline characteristics. The most useful element for their study is a thorough medical history, with an emphasis on recent trips, exposures and consumption of drugs or raw or exotic foods. Detailed histopathological analysis may help identify the etiology. For example, the presence of epithelioid granulomas with caseous necrosis indicates tuberculosis and, its absence, sarcoidosis; eosinophil abundance can be associated with drug reactions or parasitic infections; and the presence of foreign bodies can be the cause of granulomatous liver disease (GLD). In this article, we describe the basic clinical-pathological aspects of GLD, and provide a brief summary of the most common etiologies, with an emphasis on the Latin-American region.

Los granulomas son lesiones circunscritas compuestas principalmente por células mononucleares que surgen en respuesta a estímulos antigénicos pobremente degradables. Se encuentran en 2 a 15 % de las biopsias hepáticas; su hallazgo puede significar desde un fenómeno incidental, hasta la manifestación de una enfermedad sistémica de origen infeccioso, autoinmune o neoplásico. El cuadro clínico suele apuntar a la patología subyacente, sin embargo, la lista de condiciones asociadas es amplia y difiere con base en los antecedentes epidemiológicos y a las características basales del paciente. El elemento de mayor utilidad para su estudio es la historia clínica exhaustiva, con énfasis en viajes recientes, exposición de riesgo y consumo de fármacos o alimentos crudos o exóticos. El análisis histopatológico detallado puede auxiliar en la identificación de la etiología, por ejemplo, la presencia de granulomas epitelioides con necrosis caseosa indica tuberculosis y su ausencia, sarcoidosis; la abundancia de eosinófilos es señal de reacciones farmacológicas o infecciones parasitarias; la presencia de cuerpos extraños puede ser la causa de la enfermedad granulomatosa hepática. En este artículo describimos los aspectos clínico-patológicos básicos de esta enfermedad y proveemos un breve resumen de las etiologías más comunes, principalmente en la región de Latinoamérica.

Crohn’s disease and extra intestinal granulomatous lesions.

Crohn’s disease (CD) is an inflammatory bowel disease with a multifactorial etiology. Clinical features include mucosal erosion, diarrhea, weight loss and other complications such as formation of granuloma. In CD, granuloma is a non-neoplastic epithelioid lesion, formed by a compact aggregate of histiocytes with the absence of a central necrosis, however, the correlation among CD and the formation of granulomas is unknown. Many cases of granulomas in the extracellular site, related to CD, have been reported in the literature. These granulomas, at times, represented the only visible manifestation of the pathology. Extra intestinal granulomas have been found on ovaries, lungs, male genitalia, female genitalia, orofacial regions and skin. From the data in the literature it could be hypothesized that there is a cross-reaction of the immune system with similar antigenic epitopes belonging to different sites. This hypothesis, if checked, can place CD not only among inflammatory bowel disease but also among inflammatory diseases with systemic involvement.

Mathematical model of sarcoidosis.

Sarcoidosis is a disease involving abnormal collection of inflammatory cells forming nodules, called granulomas. Such granulomas occur in the lung and the mediastinal lymph nodes, in the heart, and in other vital and nonvital organs. The origin of the disease is unknown, and there are only limited clinical data on lung tissue of patients. No current model of sarcoidosis exists. In this paper we develop a mathematical model on the dynamics of the disease in the lung and use patients' lung tissue data to validate the model. The model is used to explore potential treatments.

Macrophages are required for host survival in experimental urogenital schistosomiasis.

Urogenital schistosomiasis, Schistosoma haematobium worm infection, afflicts millions of people with egg-triggered, fibrotic bladder granulomata. Despite the significant global impact of urogenital schistosomiasis, the mechanisms of bladder granulomogenesis and fibrosis are ill defined due to the prior lack of tractable animal models. We combined a mouse model of urogenital schistosomiasis with macrophage-depleting liposomal clodronate (LC) to define how macrophages mediate bladder granulomogenesis and fibrosis. Mice were injected with eggs purified from infected hamsters or vehicle prepared from uninfected hamster tissues (xenoantigen and injection trauma control). Empty liposomes were controls for LC: 1) LC treatment resulted in fewer bladder egg granuloma-infiltrating macrophages, eosinophils, and T and B cells, lower bladder and serum levels of eotaxin, and higher bladder concentrations of IL-1α and chemokines (in a time-dependent fashion), confirming that macrophages orchestrate leukocyte infiltration of the egg-exposed bladder; 2) macrophage-depleted mice exhibited greater weight loss and bladder hemorrhage postegg injection; 3) early LC treatment postegg injection resulted in profound decreases in bladder fibrosis, suggesting differing roles for macrophages in fibrosis over time; and 4) LC treatment also led to egg dose-dependent mortality, indicating that macrophages prevent death from urogenital schistosomiasis. Thus, macrophages are a potential therapeutic target for preventing or treating the bladder sequelae of urogenital schistosomiasis.

From granuloma to fibrosis: sarcoidosis associated pulmonary fibrosis.

PURPOSE OF REVIEW: Up to twenty percent of patients with sarcoidosis develop pulmonary fibrosis, transforming an often benign disease into a highly morbid and potentially fatal one. We highlight the fibrotic pulmonary sarcoidosis phenotype as an area of intense clinical and translational investigation, review recent developments in treatment, and provide a roadmap for future research in sarcoidosis associated pulmonary fibrosis. RECENT FINDINGS: Granulomatous inflammation in a lymphatic distribution is the hallmark finding of pulmonary sarcoidosis and the nidus for fibrosis. Recent research demonstrates that fibrotic sarcoidosis begins in the setting of persistent, uncontrolled inflammation, and is aided by pro-fibrotic genetic features and immune responses. Comparison to other fibrotic lung diseases also reveals key features that inform our understanding of common pathways in fibrosis. SUMMARY: Understanding the mechanisms of fibrotic transformation in sarcoidosis enhances clinical care and facilitates development of novel therapeutic options. The impact of these findings in fibrotic sarcoidosis may be amplified through application to other interstitial lung diseases marked by inflammatory to fibrotic transformation. Important aspects of clinical management of fibrotic sarcoidosis include surveillance for co-morbidities, such as pulmonary hypertension, airway disease, and infection, and assessment for pulmonary disease activity that may benefit from immunosuppression.

Clinical Characteristics of Pediatric Patients with Ocular Toxocariasis in China.

OBJECTIVE: The aim of the study was to analyze the clinical characteristics of pediatric patients with ocular toxocariasis. METHODS: Ocular toxocariasis was diagnosed and treated in 46 children from Shanghai and surrounding provinces. The diagnosis of ocular toxocariasis was confirmed immunologically by performing an enzyme-linked immunosorbent assay on serum and/or intraocular fluid. All pediatric patients and their guardians completed a questionnaire concerning their cases and living habits. RESULTS: The mean age of onset was 6 ± 3 years. Most children (85%) resided in rural areas, and 91% of the children had contact with adult dogs or puppies. At the first visit, visual acuity (VA) was <20/200 in 36 cases, and we detected peripheral granuloma in 36 patients. In our study, the most common signs were vitritis, vitreous strands, and tractional retinal detachment. The Optomap 200Tx device detected granuloma with an 85% sensitivity, which is much higher than that of other techniques. We treated 40 cases (87%) with topical corticosteroids, while 28 patients (61%) were treated with systemic corticosteroids. Only 18 children (39%) required surgical intervention. All patients were examined and treated by the same ophthalmologists. CONCLUSIONS: Preschool children in China are more often affected by toxocariasis compared with other age groups. The most common signs included unilateral granuloma and ocular inflammation. In our study, clinical manifestations were severe and complicated. At the first visit, VA was <20/200 in most patients. Ocular toxocariasis was diagnosed on the basis of clinical signs and symptoms; the diagnosis was confirmed by immunological testing. Techniques using the Optomap 200Tx device can facilitate the early detection and lead to better visual prognosis.

Sarcoidosis.

Sarcoidosis is a systemic disease of unknown cause that is characterised by the formation of immune granulomas in various organs, mainly the lungs and the lymphatic system. Studies show that sarcoidosis might be the result of an exaggerated granulomatous reaction after exposure to unidentified antigens in individuals who are genetically susceptible. Several new insights have been made, particularly with regards to the diagnosis and care of some important manifestations of sarcoidosis. The indications for endobronchial ultrasound in diagnosis and for PET in the assessment of inflammatory activity are now better specified. Recognition of unexplained persistent disabling symptoms, fatigue, small-fibre neurological impairment, cognitive failure, and changes to health state and quality of life, has improved. Mortality in patients with sarcoidosis is higher than that of the general population, mainly due to pulmonary fibrosis. Predicted advances for the future are finding the cause of sarcoidosis, and the elucidation of relevant biomarkers, reliable endpoints, and new efficient treatments, particularly in patients with refractory sarcoidosis, lung fibrosis, and those with persistent disabling symptoms.

Granulomatous pigmented purpuric dermatosis: report of a case with atypical clinical presentation including dermoscopic findings.

Granulomatous pigmented purpuric dermatosis (PPD) is a rare and poorly recognized histological variant of PPD, which commonly affects the distal extremities of mainly Far East Asian patients. Many of the reported cases are associated with hyperlipidemia or other associated systemic derangements. The authors hereby describe an additional case of granulomatous PPD affecting a 56-year-old Caucasian woman presenting unusually as a solitary lesion confined to the lower back. The report also describes dermoscopic findings, summarizes clinicopathological features of all the cases published till date, and discusses the histopathological differential diagnosis.

Indirect effects of oral tolerance inhibit pulmonary granulomas to Schistosoma mansoni eggs.

Parenteral injection of tolerated proteins into orally tolerant mice inhibits the initiation of immunological responses to unrelated proteins and blocks severe chronic inflammatory reactions of immunological origin, such as autoimmune reactions. This inhibitory effect which we have called "indirect effects of oral tolerance" is also known as "bystander suppression." Herein, we show that i.p. injection of OVA + Al(OH)(3) minutes before i.v. injection of Schistosoma mansoni eggs into OVA tolerant mice blocked the increase of pulmonary granulomas. In addition, the expression of ICAM-1 in lung parenchyma in areas outside the granulomas of OVA-orally tolerant mice was significantly reduced. However, at day 18 after granuloma induction there was no difference in immunofluorescency intensity to CD3, CD4, F4/80, andα-SMA per granuloma area of tolerant and control groups. Reduction of granulomas by reexposure to orally tolerated proteins was not correlated with a shift in Th-1/Th-2 cytokines in serum or lung tissue extract.

An in vivo canine study to assess granulomatous responses in the MedStream Programmable Infusion System (TM) and the SynchroMed II Infusion System®.

OBJECTIVE: A rare, but consistently reported complication of intrathecal (IT) delivery of opioids via programmable implantable infusion pumps is aseptic granuloma formation around the tip of the IT catheter. In the current study, the incidence and severity of IT granuloma formation was assessed for the MedStream Programmable Infusion and SynchroMed II Infusion pumps when delivering saline, baclofen, or morphine at varying concentrations and daily doses. DESIGN: Randomized study with six groups: 1) MedStream with 0.9% saline; 2) SynchroMed II with 0.9% saline; 3) MedStream with morphine sulfate; 4) SynchroMed II with morphine sulfate; 5) MedStream with baclofen; or 6) SynchroMed II with baclofen. The groups receiving morphine received either low or high concentrations (6 or 12.5 mg/mL) delivered in rates resulting in low to high (1.25-12 mg/day) daily doses. Animals receiving baclofen began at low dose/low concentration and underwent stepwise increases in concentration and dose to a maximum of 2 mg/mL/day. Animals receiving saline received a constant flow rate through either a silicone or a polyurethane IT catheter. SETTING: The study was set as in vivo laboratory experiment. SUBJECTS: 52 (21-32 kg) canines. INTERVENTIONS: Delivering IT saline, baclofen, or morphine through SynchroMed II and MedStream Programmable Infusion pumps. OUTCOME MEASURES: The incidence and severity of IT catheter tip granuloma formation was assessed with paraffin-embedded spinal cord sections by a pathologist without knowledge of treatment and compared between drug type, drug concentration, daily dose, and pump type. RESULTS: Granuloma formation occurred only in animals receiving morphine, with zero incidence in baclofen or saline infusion, regardless of catheter type. Granuloma incidence increased with increasing morphine concentration or daily dose (one [12.5%] low dose/low concentration, 3 [37.5%] low dose/high concentrations, 4 [50%] high dose/low concentration, and 7 [100%] high dose/high concentration). A granulomatous response to morphine was observed in 10 (63%) animals with SynchroMed II pumps and 5 (33%) animals with MedStream pumps, P = 0.156. CONCLUSIONS: In this in vivo canine model of IT drug delivery, catheter tip granuloma formation was associated with higher concentrations and daily doses of morphine infusion while none were seen with baclofen or saline, and was not associated with catheter type. For both pumps, granulomas were only produced in the presence of morphine infusion. These results suggest that the MedStream Programmable Infusion System has a granuloma safety profile at least equivalent to that of the SynchroMed II pump.

Serum amyloid A regulates granulomatous inflammation in sarcoidosis through Toll-like receptor-2.

RATIONALE: The critical innate immune mechanisms that regulate granulomatous inflammation in sarcoidosis are unknown. Because the granuloma-inducing component of sarcoidosis tissues has physicochemical properties similar to those of amyloid fibrils, we hypothesized that host proteins capable of forming poorly soluble aggregates or amyloid regulate inflammation in sarcoidosis. OBJECTIVES: To determine the role of the amyloid precursor protein, serum amyloid A, as an innate regulator of granulomatous inflammation in sarcoidosis. METHODS: Serum amyloid A expression was determined by immunohistochemistry in sarcoidosis and control tissues and by ELISA. The effect of serum amyloid A on nuclear factor (NF)-kappaB induction, cytokine expression, and Toll-like receptor-2 stimulation was determined with transformed human cell lines and bronchoalveolar lavage cells from patients with sarcoidosis. The effects of serum amyloid A on regulating helper T cell type 1 (Th1) granulomatous inflammation were determined in experimental models of sarcoidosis, using Mycobacterium tuberculosis catalase-peroxidase. MEASUREMENTS AND MAIN RESULTS: We found that the intensity of expression and distribution of serum amyloid A within sarcoidosis granulomas was unlike that in many other granulomatous diseases. Serum amyloid A localized to macrophages and giant cells within sarcoidosis granulomas but correlated with CD3(+) lymphocytes, linking expression to local Th1 responses. Serum amyloid A activated NF-kappaB in Toll-like receptor-2-expressing human cell lines; regulated experimental Th1-mediated granulomatous inflammation through IFN-gamma, tumor necrosis factor, IL-10, and Toll-like receptor-2; and stimulated production of tumor necrosis factor, IL-10, and IL-18 in lung cells from patients with sarcoidosis, effects inhibited by blocking Toll-like receptor-2. CONCLUSIONS: Serum amyloid A is a constituent and innate regulator of granulomatous inflammation in sarcoidosis through Toll-like receptor-2, providing a mechanism for chronic disease and new therapeutic targets.