M. tuberculosis relies on trace oxygen to maintain energy homeostasis and survive in hypoxic environments

The bioenergetic mechanisms by which Mycobacterium tuberculosis survives hypoxia are poorly understood. Current models assume that the bacterium shifts to an alternate electron acceptor or fermentation to maintain membrane potential and ATP synthesis. Counterintuitively, we find here that oxygen itself is the principal terminal electron acceptor during hypoxic dormancy. M. tuberculosis can metabolize oxygen efficiently at least two orders of magnitude below the concentration predicted to occur in hypoxic lung granulomas. Despite a difference in apparent affinity for oxygen, both the cytochrome bcc:aa₃ and cytochrome bd oxidase respiratory branches are required for hypoxic respiration. Simultaneous inhibition of both oxidases blocks oxygen consumption, reduces ATP levels, and kills M. tuberculosis under hypoxia. The capacity of mycobacteria to scavenge trace levels of oxygen, coupled with the absence of complex regulatory mechanisms to achieve hierarchal control of the terminal oxidases, may be a key determinant of long-term M. tuberculosis survival in hypoxic lung granulomas.

Infection Due to Actinobacillus lignieresii in Cattle with Brain and Ocular Involvement: Histological and Microbiological Features

The actinobacillosis is rare and to date the biological profile of the agent is not yet fully understood. The knowledge about the possible hosts of the pathogen is incomplete and is generally only associated with granulomatous lesions in cattle and sheep. The primary organs involved are the mouth, tongue and pharynx. Human infection is extremely rare. Actinobacillus lignieresii is the causative agent of a rare bovine granulomatous disease known as "wooden tongue". In this research, we describe a case of cerebral and ocular metastatic diffusion of granuloma due to infection with Actinobacillus lignieresii in cattle, probably resulting from primary oral localization. Diagnosis was made using histopathological assay which made it possible to highlight the typical lesion of actinobacillosis, and bacteriological assay that allowed to isolate the pathogen.

Mycobacterium tuberculosis-Specific CD4 T Cells Expressing Transcription Factors T-Bet or RORγT Associate with Bacterial Control in Granulomas

Despite the extensive research on CD4 T cells within the context of Mycobacterium tuberculosis (Mtb) infections, few studies have focused on identifying and investigating the profile of Mtb-specific T cells within lung granulomas. To facilitate the identification of Mtb-specific CD4 T cells, we identified immunodominant epitopes for two Mtb proteins, namely, Rv1196 and Rv0125, using a Mauritian cynomolgus macaque model of Mtb infection, thereby providing data for the synthesis of MHC class II tetramers. Using tetramers, we identified Mtb-specific cells within different immune compartments, postinfection. We found that granulomas were enriched sites for Mtb-specific cells and that tetramer⁺ cells had increased frequencies of the activation marker CD69 as well as the transcription factors T-bet and RORγT, compared to tetramer negative cells within the same sample. Our data revealed that while the frequency of Rv1196 tetramer⁺ cells was positively correlated with the granuloma bacterial burden, the frequency of RORγT or T-bet within tetramer⁺ cells was inversely correlated with the granuloma bacterial burden, thereby highlighting the importance of having activated, polarized, Mtb-specific cells for the control of Mtb in lung granulomas. IMPORTANCE Tuberculosis, caused by the bacterial pathogen Mycobacterium tuberculosis, kills 1.5 million people each year, despite the existence of effective drugs and a vaccine that is given to infants in most countries. Clearly, we need better vaccines against this disease. However, our understanding of the immune responses that are necessary to prevent tuberculosis is incomplete. This study seeks to understand the functions of T cells that are specific for M. tuberculosis at the site of the disease in the lungs. For this, we developed specialized tools called MHC class II tetramers to identify those T cells that can recognize M. tuberculosis and applied the tools to the study of this infection in nonhuman primate models that mimic human tuberculosis. We demonstrate that M. tuberculosis-specific T cells in lung lesions are associated with control of the bacteria only when those T cells are expressing certain functions, thereby highlighting the importance of combining the identification of specific T cells with functional analyses. Thus, we surmise that these functions of specific T cells are critical to the control of infection and should be considered as a part of the development of vaccines against tuberculosis.

Intragranuloma Accumulation and Inflammatory Differentiation of Neutrophils Underlie Mycobacterial ESX-1-Dependent Immunopathology

The conserved ESX-1 type VII secretion system is a major virulence determinant of pathogenic mycobacteria, including Mycobacterium tuberculosis and Mycobacterium marinum. ESX-1 is known to interact with infected macrophages, but its potential roles in regulating other host cells and immunopathology have remained largely unexplored. Using a murine M. marinum infection model, we identify neutrophils and Ly6C⁺MHCII⁺ monocytes as the main cellular reservoirs for the bacteria. We show that ESX-1 promotes intragranuloma accumulation of neutrophils and that neutrophils have a previously unrecognized required role in executing ESX-1-mediated pathology. To explore if ESX-1 also regulates the function of recruited neutrophils, we performed a single-cell RNA-sequencing analysis that indicated that ESX-1 drives newly recruited uninfected neutrophils into an inflammatory phenotype via an extrinsic mechanism. In contrast, monocytes restricted the accumulation of neutrophils and immunopathology, demonstrating a major host-protective function for monocytes specifically by suppressing ESX-1-dependent neutrophilic inflammation. Inducible nitric oxide synthase (iNOS) activity was required for the suppressive mechanism, and we identified Ly6C⁺MHCII⁺ monocytes as the main iNOS-expressing cell type in the infected tissue. These results suggest that ESX-1 mediates immunopathology by promoting neutrophil accumulation and phenotypic differentiation in the infected tissue, and they demonstrate an antagonistic interplay between monocytes and neutrophils by which monocytes suppress host-detrimental neutrophilic inflammation. IMPORTANCE The ESX-1 type VII secretion system is required for virulence of pathogenic mycobacteria, including Mycobacterium tuberculosis. ESX-1 interacts with infected macrophages, but its potential roles in regulating other host cells and immunopathology have remained largely unexplored. We demonstrate that ESX-1 promotes immunopathology by driving intragranuloma accumulation of neutrophils, which upon arrival adopt an inflammatory phenotype in an ESX-1-dependent manner. In contrast, monocytes limited the accumulation of neutrophils and neutrophil-mediated pathology via an iNOS-dependent mechanism, suggesting a major host-protective function for monocytes specifically by restricting ESX-1-dependent neutrophilic inflammation. These findings provide insight into how ESX-1 promotes disease, and they reveal an antagonistic functional relationship between monocytes and neutrophils that might regulate immunopathology not only in mycobacterial infection but also in other infections as well as in inflammatory conditions and cancer.

Nocardia seriolae mediates liver granulomatous chronic inflammation in Micropterus salmoides through pyroptosis

Granulomatous diseases caused by Nocardia seriously endanger the health of cultured fish. These bacteria are widely distributed, but prevention and treatment methods are very limited. Chronic granulomatous inflammation is an important pathological feature of Nocardia infection. However, the molecular mechanisms of granuloma formation and chronic inflammation are still unclear. Constructing a granuloma infection model of Nocardia is the key to exploring the pathogenesis of the disease. In this study, we established a granuloma model in the liver of largemouth bass (Micropterus salmoides) and assessed the infection process of Nocardia seriolae at different concentrations by analysing relevant pathological features. By measuring the expression of pro-inflammatory cytokines, transcription factors and a pyroptosis-related protein, we revealed the close relationship between pyroptosis and chronic inflammation of granulomas. We further analysed the immunofluorescence results and the expression of pyroptosis-related protein of macrophage infected by N. seriolae and found that N. seriolae infection induced macrophage pyroptosis in vitro. These results were proved by flow cytometry analysis of infection experiment in vivo. Our results indicated that the pyroptosis effect may be the key to inducing chronic inflammation in the fish liver and further mediating granuloma formation. In this study, we explored the molecular mechanism underlying chronic inflammation of granulomas and developed research ideas for understanding the occurrence and development of granulomatous diseases in fish.

Neurosarcoidosis Presenting as Longitudinally Extensive Transverse Myelitis and Orbital Mass: A Case Report

We describe a case of neurosarcoidosis in a 64-year-old female who presented with proptosis and orbital inflammation together with bilateral lower extremity neuropathy and longitudinally extensive transverse myelitis. These two entities are not commonly associated, and the etiology of the transverse myelitis was facilitated by an orbital biopsy. The transverse myelitis caused numbness in her lower extremities and tightness in her chest and abdomen, which progressed over weeks to difficulty walking and bilateral neuromuscular weakness. Magnetic resonance imaging (MRI) revealed longitudinally extensive transverse myelitis in the cervical and thoracic spine. Computed tomography (CT) imaging of the chest revealed right hilar and mediastinal lymphadenopathy and calcified subcarinal nodes. Positron emission tomography (PET) scan revealed hypermetabolism in the mediastinum and medial left orbit. Orbital biopsy revealed non-necrotizing granulomatous inflammation suggestive of sarcoidosis. The neurologic deficits and orbital inflammation responded well to intravenous corticosteroids. Neurosarcoidosis can present with unusual clinical manifestations, as evidenced by this patient.

Sarcoid-like Uveitis with or without Tubulointerstitial Nephritis during COVID-19

PURPOSE

To report sarcoid-like uveitis with or without tubulointerstitial nephritis (TIN) during coronavirus disease 2019 (COVID-19) and to discuss diagnostic evaluation and treatment.

METHODS

Detailed information on the subject's demographics, medical history, ophthalmic examination findings, and laboratory results were obtained from medical records. Fluorescein angiography (FA) and indocyanine green angiography (ICGA) images were evaluated.

RESULTS

All seven patients aged between 8 and 17 had bilateral granulomatous panuveitis. TIN preceded in four patients. Thorax computed tomography of patient 1 was found to be compatible with COVID-19, patients 2 and 3 were in contact with Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) positive parents, patients 4 and 5 were found to be SARS-CoV-2 PCR positive, and patients 6 and 7 were positive for SARS-CoV-2 IgG antibodies. ICGA revealed hypofluorescent dots in six patients. Intraocular inflammation was controlled with corticosteroid and/or immunomodulatory therapy. Visual acuity was maintained or improved in all.

CONCLUSION

SARS-CoV-2 infection may be related to sarcoid-like uveitis and acute tubulointerstitial nephritis.

Focal Abscess: Description of a clinical case

Purpose The purpose of this article is to present a case report of a periapical lesion found in a 24-year-old female who presented to a university dental hygiene clinic with a chief complaint of vestibular pain around tooth #22. Radiographically, the lesion appeared radiolucent and unilocular with well-defined borders and significant bone resorption. The area of radiolucency increased in size over a period of five weeks indicating an aggressive pathosis. Given the clinical and radiographic presentations, the differential diagnosis included an odontogenic keratocystic tumor (odontogenic keratocyst), central giant cell granuloma, periapical cyst, and squamous cell carcinoma. Biopsy revealed the diagnosis of a focal abscess. The patient's presenting signs and symptoms are reviewed. Management and contributing factors are discussed.

Idiopathic granulomatous mastitis and cystic neutrophilic granulomatous mastitis: two sides of the same coin or distinct entities?

Idiopathic granulomatous mastitis (IGM) is a benign mimic of breast carcinomas. It is defined histologically by the presence of granulomas and inflammation. The closely related cystic neutrophilic granulomatous mastitis (CNGM) shows lipogranulomas, with a reported association with corynebacteria. A large cohort of IGM was reviewed to compare clinical, microbiological and histological features between non-CNGM IGM and CNGM. Cases of IGM were reviewed for histological parameters including the presence of lipogranulomas and composition of inflammatory cells. Clinical data were obtained through hospital records. The cohort included 79 cases, including 51 non-CNGM IGM and 28 CNGM. Comparing non-CNGM IGM and CNGM, there were no differences in clinical or demographical data, other than a younger age of presentation (36.2 vs 41.5 years, p=0.012) for CNGM. Most IGM resolved within the follow-up period (n=57/64, 89.1%), with similar outcomes regardless of treatment (p>0.05). In CNGM, there were more infiltrates of neutrophils (p=0.001), histiocytes (p=0.047), and multinucleated giant cells (p=0.006), but less lymphocytes (p=0.008). Corynebacteria was cultured in two (25%) cases of CNGM, and one non-CNGM IGM (14.3%). Gram-positive bacilli were identified in two cases of CNGM. 'Early' lipogranulomas were observed closely associated to inflamed ducts in three cases of CNGM. Apart from age, there was no distinct clinical or microbiological feature for CNGM. These findings do not support CNGM as a distinct entity. Rather, CNGM-pattern may represent a continuum of IGM, possibly age-related and attributable to ductal inflammation and cystic changes in the breast parenchyma.

A case of etanercept (anti-TNF agent) induced granulomas on the lids

Sarcoid-like granulomas are a rare adverse effect of TNF-α inhibitors that are becoming increasingly reported in the literature. A retrospective study in France estimated this adverse effect to occur in 0.04% patients. We report an important reversible cause that is more commonly being seen.A 70 year old lady presented with multiple lesions on her lids in the ophthalmology clinic. Histology confirmed that they were sarcoid-like granulomas. The patient had been started on etanercept (anti-TNF agent) a few months prior for rheumatoid arthritis. Investigations were undertaken to rule out differentials such as autoimmune conditions and infective causes like tuberculosis.After ruling out an active inflammatory disease and an autoimmune cause, etanercept induced granulomas were considered. Etanercept was stopped. This resulted in the resolution of granulomas over the course of a few months.Etanercept induced granulomas resolve when the anti-TNF agent is discontinued; however, some patients may require treatment with steroids.As this case demonstrates, ophthalmologists should be aware that anti-TNF agents can cause non-caseating granulomas, which can be cutaneous or pulmonary. This can help to result in more prompt diagnoses and appropriate treatment.

Metastatic pulmonary pleomorphic carcinoma replaced by a granulomatous lesion after spontaneous regression and PD-1 blockade-induced regression: can epithelioid granuloma be a histological hallmark of cancer immunity?

Immune checkpoint inhibitors (ICIs) for various types of malignancy, including non-small-cell lung cancer, have improved prognosis in some cases. Granuloma formation after ICI administration suggests a tumor antigen-specific cytotoxic T cell response with abundant interferon-gamma production, which can be used to estimate the curative effect of ICIs. In this report, we present a case with a resected lung lesion, clinically suspected to be lung cancer, that consisted of a granulomatous lesion. A tumor was also found in the duodenum that was presumed to be derived from the pulmonary pleomorphic carcinoma. Duodenal tumor cells highly expressed PD-L1, suggesting PD-1/PD-L1 axis-mediated immune escape. As expected, pembrolizumab induced a complete response for the duodenal lesion. Interestingly, in histopathological analysis, the duodenal lesion was also replaced by an epithelial granuloma and multinucleated giant cells. We conclude that autoimmunity regressed the untreated primary lung lesion spontaneously, while the metastatic duodenal lesion responded to PD-1 blockade. Tumor-associated epithelioid granulomas, even before ICI administration, may be an important pathological finding indicating an immune response with interferon-gamma production by cytotoxic T cells to the tumor.

Surgical excision of peripheral giant cell granuloma of the maxilla: a case report

Peripheral giant cell granuloma (PGCG) is described as an elevated lesion that is located mostly on the gingival mucosa and alveolar crest, consecutive to irritative factors and trauma. It predominantly occurs more in the mandible than the maxilla, and it is usually seen in the 4^th to the 6^th decades. The clinical appearance of this lesion is red-bluish in color, presenting a similar tissue to the one observed in the liver, usually measuring less than 2 cm. The treatment of the PGCG is the surgical excision. The recurrence of this lesion is rarely described in the literature. The present case highlights the importance of considering the traumatic extractions as one of the main uncommon etiologic factors, leading to the development of peripheral giant cell granuloma. It precisely describes the diagnosis, the treatment of a peripheral giant cell granuloma located in maxillary canine-premolar region, occurred consecutively after ancient traumatic extractions of the 13 and 14 since 1 year. This paper also reports a maxillary location of giant cell granuloma, while the literature reports more commonly the mandibular location. This lesion was excised surgically, and healed uneventually, and in which the follow-up didn´t show any sign of recurrence.

Primary nasal tuberculosis: A rare case report

Nasal primary tuberculosis (TB) of the upper respiratory tract is rare and barely reported in literature. Herein, we report a complicated case of nasal primary TB with otitis media. The patient visited the ENT clinic due to left-side nasal obstruction accompanied by rhinorrhea, and intermittent headaches. The diagnosis of nasal TB was confirmed with an acid-fast bacterial test and histopathological examination. After 3 months of treatment with anti-TB drugs, patient's symptoms of nasal obstruction, rhinorrhea, and other symptoms were remarkably relieved. The left ear purulence substantially reduced. The patient recovered well and had no recurrence post half a year of follow-up. Our case emphasizes the importance of accurate diagnosis and initiation of timely treatment. Additionally, when a patient has nasal TB complicated with otitis media, it is important to consider a diagnosis of middle ear TB.

Sarcoid-Like Reaction in the Kidney Following Rituximab for Mantle Lymphoma in a 60-Year-Old Man

The sarcoid-like reaction is a rare autoinflammatory disease that can affect lymph nodes or organs but does not meet the diagnostic criteria for systemic sarcoidosis. Several drug classes have been associated with the development of a systemic sarcoid-like reaction, which defines drug-induced sarcoidosis-like reactions and can affect a single organ. Anti-CD20 antibodies (rituximab) have rarely been reported as responsible for this reaction and this adverse effect has mainly been described during the treatment of Hodgkin's lymphoma. We report a unique case of a sarcoid-like reaction complicating rituximab following the treatment of a mantle cell lymphoma and interesting only the kidney. The 60-year-old patient presented with severe acute renal failure 6 months after the end of his r-CHOP protocol and the urgent renal biopsy revealed acute interstitial nephritis rich in granulomas without caseous necrosis. After ruling out other causes of granulomatous nephritis, a sarcoid-like reaction was retained since infiltration was limited to the kidney. The temporal relationship between rituximab administration and the sarcoid-like reaction onset in our patient supported the diagnosis of a rituximab-induced sarcoidosis-like reaction. Oral corticosteroid treatment led to rapid and lasting improvement in renal function. Clinicians should be warned of this adverse effect and regular and prolonged monitoring of renal function should be recommended during the follow-up of patients after the end of treatment with rituximab.

Macrophage Biology in Human Granulomatous Skin Inflammation

Cutaneous granulomatoses represent a heterogeneous group of diseases, which are defined by macrophage infiltration in the skin. Skin granuloma can be formed in the context of infectious and non-infectious conditions. Recent technological advances have deepened our understanding of the pathophysiology of granulomatous skin inflammation, and they provide novel insights into human tissue macrophage biology at the site of ongoing disease. Here, we discuss findings on macrophage immune function and metabolism derived from three prototypic cutaneous granulomatoses: granuloma annulare, sarcoidosis, and leprosy.

Single-cell and spatial transcriptomics reveal aberrant lymphoid developmental programs driving granuloma formation

Granulomas are lumps of immune cells that can form in various organs. Most granulomas appear unstructured, yet they have some resemblance to lymphoid organs. To better understand granuloma formation, we performed single-cell sequencing and spatial transcriptomics on granulomas from patients with sarcoidosis and bioinformatically reconstructed the underlying gene regulatory networks. We discovered an immune stimulatory environment in granulomas that repurposes transcriptional programs associated with lymphoid organ development. Granuloma formation followed characteristic spatial patterns and involved genes linked to immunometabolism, cytokine and chemokine signaling, and extracellular matrix remodeling. Three cell types emerged as key players in granuloma formation: metabolically reprogrammed macrophages, cytokine-producing Th17.1 cells, and fibroblasts with inflammatory and tissue-remodeling phenotypes. Pharmacological inhibition of one of the identified processes attenuated granuloma formation in a sarcoidosis mouse model. We show that human granulomas adopt characteristic aspects of normal lymphoid organ development in aberrant combinations, indicating that granulomas constitute aberrant lymphoid organs.

Cutaneous sarcoidosis mimicking pigmented purpuric dermatosis

Sarcoidosis is a systemic inflammatory disorder characterized by the formation of non-caseating granulomas. Cutaneous involvement of sarcoidosis is common and has a wide variety of clinical presentations. Herein, we present a case of cutaneous sarcoidosis mimicking pigmented purpuric dermatosis (PPD) in a 26-year-old female treated with topical tofacitinib cream and a literature review of all other reported cases of cutaneous sarcoidosis with PPD-like features.

Rare forms of inflammatory myopathies - part I, generalized forms

INTRODUCTION

The idiopathic inflammatory myopathies traditionally comprise dermatomyositis, polymyositis, immune-mediated necrotizing myopathy, anti-synthetase syndrome, and inclusion body myositis. In this review, we aimed to cover the less common forms of generalized myositis.

AREAS COVERED

We identified rare forms of widespread myositis on the basis of list provided by the homepage of the Neuromuscular disease center of Washington University, USA and on the basis of the authors' knowledge. We searched PubMed® and EMBASE® for relevant articles on these forms with the aim of providing as much as possible information on their clinical manifestations as well as guidance on their work-up and treatment.

EXPERT OPINION

There is substantial heterogeneity among the various rare forms of generalized myositis in terms of their frequency and characterization. Some forms are reasonably well defined, while others may not represent truly well-defined diseases, but rather variants of other myopathies. The landscape of rare forms appears to have evolved over time, with some forms now being better characterized, while others, such as SARS-Cov-2- and immune checkpoint inhibitor-related myositis have come to the fore only in recent years. Knowledge about rare forms of myositis can aid in their recognition and treatment.

The magnetic resonance imaging characteristics of radicular cysts and granulomas

OBJECTIVES

Limited studies have differentiated radicular cysts and granulomas with MRI. Therefore, we investigated the MRI characteristics of the two lesions and clarified features for distinguishing between them.

METHODS

We collected data of 27 radicular cysts and 9 granulomas definitively diagnosed by histopathology and reviewed the fat-saturated T2 weighted, T1 weighted, and contrast-enhanced fat-saturated T1 weighted images. We measured the maximum diameter and apparent diffusion coefficient values of the lesions. We employed Fisher's exact test, the Mann-Whitney U test, and independent t-tests to compare the two lesions and created a decision tree for discriminating between them.

RESULTS

There were significant differences between radicular cysts and granulomas with respect to five imaging characteristics-signal intensity of the lesion centre on fat-saturated T2 weighted images; signal intensity, texture, and contrast enhancement of the lesion centre on contrast-enhanced fat-saturated T1 weighted images; and maximum diameter of the lesion. The cut-off diameter for radicular cysts was 15.9 mm. The area under the receiver operating characteristic curve, sensitivity, and specificity were 0.971, 85.2%, and 100%, respectively.

CONCLUSIONS

From the decision tree analysis, maximum diameter, lesion centre contrast enhancement on contrast-enhanced fat-saturated T1 weighted images, and lesion centre signal intensity on fat-saturated T2 weighted images were important for discriminating between radicular cysts and granulomas.

Choroidal Lymphoma: Diagnostic Value of Combined Indocyanine Green Angiography and Optical Coherence Tomography

OBJECTIVE

To compare multimodal imaging findings in patients with choroidal lymphoma (CL).

METHODS

Multicenter retrospective observational case series. Multimodal imaging features of patients with CL were reviewed with particular attention to the patterns of choroidal infiltration on indocyanine green angiography (ICGA) and optical coherence tomography (OCT).

RESULTS

Eighteen eyes of 15 patients were included in this study. Average tumor thickness on ultrasonography was 2.6 mm (range, 1.2-5.7 mm). Choroidal infiltration on ICGA was characterized by multifocal, round areas (300-500 microns diameter) of hypocyanescence in all cases, whereas OCT at the same region disclosed diffuse choroidal infiltration. By OCT, the tumor surface contour was primarily placid (22%), dome-shaped (11%), or undulating (67%).

CONCLUSIONS

In this analysis of eyes with CL, ICGA demonstrated multifocal sub-millimeter regions of choroidal hypocyanescence whereas OCT documented diffuse choroidal infiltration. This incongruence could be a distinctive diagnostic feature of choroidal lymphoma, assisting with differentiation from other pathological entities.

Atorvastatin Potentially Reduces Mycobacterial Severity through Its Action on Lipoarabinomannan and Drug Permeability in Granulomas

The majority of preclinical research has shown that Mycobacterium tuberculosis can modify host lipids in various ways. To boost its intramacrophage survival, M. tuberculosis causes host lipids to build up, resulting in the development of lipid-laden foam cells. M. tuberculosis binds to and enters the macrophage via the cell membrane cholesterol. Aggregation of cholesterol in the cell wall of M. tuberculosis and an increase in vascularity at the granuloma site reduce the permeability of rifampicin and isoniazid concentrations. However, very few studies have assessed the effect of statins on drug penetration. Here, we used atorvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, to observe its effect on the bacterial burden by increasing the drug concentration at the infection site. We looked into how atorvastatin could be used in conjunction with first-line drugs to promote drug permeation. In this study, we detected an accumulation of drugs at the peripheral sites of the lungs and impaired drug distribution to the diseased sites. The efficacy of antituberculosis drugs, with atorvastatin as an adjunct, on the viability of M. tuberculosis cells was demonstrated. A nontoxic statin dosage established phenotypic and normal granuloma vasculature and showed an additive effect with rifampicin and isoniazid. Our data show that statins help to reduce the tuberculosis bacterial burden. Our findings reveal that the bacterial load is connected with impaired drug permeability resulting from lipid accumulation in the bacterial cell wall. Statin therapy combined with antituberculosis medications have the potential to improve treatment in tuberculosis patients. IMPORTANCE Mycobacterium tuberculosis binds to and enters the macrophage via the cell membrane cholesterol. M. tuberculosis limits phagosomal maturation and activation without engaging in phagocytosis. Aggregation of cholesterol in the cell wall of M. tuberculosis and an increase in the vascularity at the granuloma site reduce the permeability of rifampicin and isoniazid concentrations. However, very few studies have assessed the effect of statins on drug penetration, which can be increased through a reduction in cholesterol and vascularity. Herein, we used atorvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, to observe its effect on bacterial burden through increasing the drug concentration at the infection site. Our main research goal is to diminish mycobacterial dissemination and attenuate bacterial growth by increasing drug permeability.

Potential Association of Cutibacterium acnes with Sarcoidosis as an Endogenous Hypersensitivity Infection

The immunohistochemical detection of Cutibacterium acnes in sarcoid granulomas suggests its potential role in granuloma formation. C. acnes is the sole microorganism ever isolated from sarcoid lesions. Histopathologic analysis of some sarcoid lymph nodes reveals latent infection and intracellular proliferation of cell-wall-deficient C. acnes followed by insoluble immune-complex formation. Activation of T helper type 1 (Th1) immune responses by C. acnes is generally higher in sarcoidosis patients than in healthy individuals. Pulmonary granulomatosis caused by an experimental adjuvant-induced allergic immune response to C. acnes is preventable by antimicrobials, suggesting that the allergic reaction targets C. acnes commensal in the lungs. C. acnes is the most common bacterium detected intracellularly in human peripheral lungs and mediastinal lymph nodes. Some sarcoidosis patients have increased amounts of C. acnes-derived circulating immune complexes, which suggests the proliferation of C. acnes in affected organs. In predisposed individuals with hypersensitive Th1 immune responses to C. acnes, granulomas may form to confine the intracellular proliferation of latent C. acnes triggered by certain host-related or drug-induced conditions. Current clinical trials in patients with cardiac sarcoidosis are evaluating combined treatment with steroids and antimicrobials during active disease with continued antimicrobial therapy while tapering off steroids after the disease subsides.