1
|
Li R, Li J, Zhou X. Lung microbiome: new insights into the pathogenesis of respiratory diseases. Signal Transduct Target Ther 2024; 9:19. [PMID: 38228603 DOI: 10.1038/s41392-023-01722-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 10/25/2023] [Accepted: 11/22/2023] [Indexed: 01/18/2024] Open
Abstract
The lungs were long thought to be sterile until technical advances uncovered the presence of the lung microbial community. The microbiome of healthy lungs is mainly derived from the upper respiratory tract (URT) microbiome but also has its own characteristic flora. The selection mechanisms in the lung, including clearance by coughing, pulmonary macrophages, the oscillation of respiratory cilia, and bacterial inhibition by alveolar surfactant, keep the microbiome transient and mobile, which is different from the microbiome in other organs. The pulmonary bacteriome has been intensively studied recently, but relatively little research has focused on the mycobiome and virome. This up-to-date review retrospectively summarizes the lung microbiome's history, composition, and function. We focus on the interaction of the lung microbiome with the oropharynx and gut microbiome and emphasize the role it plays in the innate and adaptive immune responses. More importantly, we focus on multiple respiratory diseases, including asthma, chronic obstructive pulmonary disease (COPD), fibrosis, bronchiectasis, and pneumonia. The impact of the lung microbiome on coronavirus disease 2019 (COVID-19) and lung cancer has also been comprehensively studied. Furthermore, by summarizing the therapeutic potential of the lung microbiome in lung diseases and examining the shortcomings of the field, we propose an outlook of the direction of lung microbiome research.
Collapse
Affiliation(s)
- Ruomeng Li
- Department of Biotherapy, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, 610041, China
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Chinese Academy of Medical Sciences Research Unit of Oral Carcinogenesis and Management, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, 610041, China
| | - Jing Li
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Chinese Academy of Medical Sciences Research Unit of Oral Carcinogenesis and Management, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, 610041, China.
| | - Xikun Zhou
- Department of Biotherapy, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, 610041, China.
| |
Collapse
|
2
|
Potential Association of Cutibacterium acnes with Sarcoidosis as an Endogenous Hypersensitivity Infection. Microorganisms 2023; 11:microorganisms11020289. [PMID: 36838255 PMCID: PMC9964181 DOI: 10.3390/microorganisms11020289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 01/18/2023] [Accepted: 01/19/2023] [Indexed: 01/26/2023] Open
Abstract
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.
Collapse
|
3
|
Isshiki T, Homma S, Eishi Y, Yabe M, Koyama K, Nishioka Y, Yamaguchi T, Uchida K, Yamamoto K, Ohashi K, Arakawa A, Shibuya K, Sakamoto S, Kishi K. Immunohistochemical Detection of Propionibacterium acnes in Granulomas for Differentiating Sarcoidosis from Other Granulomatous Diseases Utilizing an Automated System with a Commercially Available PAB Antibody. Microorganisms 2021; 9:microorganisms9081668. [PMID: 34442747 PMCID: PMC8401915 DOI: 10.3390/microorganisms9081668] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Revised: 07/26/2021] [Accepted: 07/30/2021] [Indexed: 01/11/2023] Open
Abstract
Propionibacterium acnes is implicated in the pathogenesis of sarcoidosis. We investigated the usefulness of immunohistochemistry (IHC) with a commercially available P. acnes-specific monoclonal antibody (PAB antibody) for differentiating sarcoidosis from other granulomatous diseases. Formalin-fixed paraffin-embedded tissue samples from 94 sarcoidosis patients and 30 control patients with other granulomatous diseases were examined by the original manual IHC method. We also compared the detection frequency of P. acnes in sarcoid granulomas between manual and automated IHC methods. P. acnes was detected in sarcoid granulomas of samples obtained by transbronchial lung biopsy (64%), video-associated thoracic surgery (67%), endobronchial-ultrasound-guided transbronchial-needle aspiration (32%), lymph node biopsy (80%), and skin biopsy (80%) from sarcoidosis patients, but not in any non-sarcoid granulomas of the samples obtained from control patients. P. acnes outside granulomas, however, was frequently detected in both groups. The detection status of P. acnes in granulomas did not correlate with the clinical characteristics of sarcoidosis patients. The automated Leica system exhibited the best detection sensitivity (72%) and almost an identical localization for P. acnes in sarcoid granulomas compared with the manual method. IHC with a PAB antibody is useful for differentiating sarcoidosis from other granulomatous diseases by detecting P. acnes in granulomas. An automated method by the Leica system can be used in pathology laboratories for differential diagnosis of granulomas by IHC with the PAB antibody.
Collapse
Affiliation(s)
- Takuma Isshiki
- Department of Respiratory Medicine, School of Medicine, Toho University, Tokyo 143-8541, Japan; (T.I.); (S.S.); (K.K.)
| | - Sakae Homma
- Department of Advanced and Integrated Interstitial Lung Diseases Research, School of Medicine, Toho University, Tokyo 143-8540, Japan; (M.Y.); (K.K.)
- Correspondence:
| | - Yoshinobu Eishi
- Department of Human Pathology, Graduate School and Faculty of Medicine, Tokyo Medical and Dental University, Tokyo 113-8519, Japan; (Y.E.); (T.Y.); (K.U.); (K.Y.); (K.O.)
| | - Matsuko Yabe
- Department of Advanced and Integrated Interstitial Lung Diseases Research, School of Medicine, Toho University, Tokyo 143-8540, Japan; (M.Y.); (K.K.)
| | - Kazuya Koyama
- Department of Advanced and Integrated Interstitial Lung Diseases Research, School of Medicine, Toho University, Tokyo 143-8540, Japan; (M.Y.); (K.K.)
- Department of Respiratory Medicine and Rheumatology, Graduate School of Biomedical Sciences, Tokushima University, Tokushima 770-8503, Japan;
| | - Yasuhiko Nishioka
- Department of Respiratory Medicine and Rheumatology, Graduate School of Biomedical Sciences, Tokushima University, Tokushima 770-8503, Japan;
| | - Tetsuo Yamaguchi
- Department of Human Pathology, Graduate School and Faculty of Medicine, Tokyo Medical and Dental University, Tokyo 113-8519, Japan; (Y.E.); (T.Y.); (K.U.); (K.Y.); (K.O.)
- Department of Pulmonology, Shinjuku Tsurukame Clinic, Tokyo 151-0053, Japan
| | - Keisuke Uchida
- Department of Human Pathology, Graduate School and Faculty of Medicine, Tokyo Medical and Dental University, Tokyo 113-8519, Japan; (Y.E.); (T.Y.); (K.U.); (K.Y.); (K.O.)
| | - Kurara Yamamoto
- Department of Human Pathology, Graduate School and Faculty of Medicine, Tokyo Medical and Dental University, Tokyo 113-8519, Japan; (Y.E.); (T.Y.); (K.U.); (K.Y.); (K.O.)
| | - Kenichi Ohashi
- Department of Human Pathology, Graduate School and Faculty of Medicine, Tokyo Medical and Dental University, Tokyo 113-8519, Japan; (Y.E.); (T.Y.); (K.U.); (K.Y.); (K.O.)
| | - Atsushi Arakawa
- Department of Human Pathology, School of Medicine, Juntendo University, Tokyo 113-8421, Japan;
| | - Kazutoshi Shibuya
- Department of Pathology, School of Medicine, Toho University, Tokyo 143-8541, Japan;
| | - Susumu Sakamoto
- Department of Respiratory Medicine, School of Medicine, Toho University, Tokyo 143-8541, Japan; (T.I.); (S.S.); (K.K.)
| | - Kazuma Kishi
- Department of Respiratory Medicine, School of Medicine, Toho University, Tokyo 143-8541, Japan; (T.I.); (S.S.); (K.K.)
| |
Collapse
|
4
|
Yamaguchi T, Costabel U, McDowell A, Guzman J, Uchida K, Ohashi K, Eishi Y. Immunohistochemical Detection of Potential Microbial Antigens in Granulomas in the Diagnosis of Sarcoidosis. J Clin Med 2021; 10:jcm10050983. [PMID: 33801218 PMCID: PMC7957865 DOI: 10.3390/jcm10050983] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 02/17/2021] [Accepted: 02/23/2021] [Indexed: 01/06/2023] Open
Abstract
Sarcoidosis may have more than a single causative agent, including infectious and non-infectious agents. Among the potential infectious causes of sarcoidosis, Mycobacterium tuberculosis and Propionibacterium acnes are the most likely microorganisms. Potential latent infection by both microorganisms complicates the findings of molecular and immunologic studies. Immune responses to potential infectious agents of sarcoidosis should be considered together with the microorganisms detected in sarcoid granulomas, because immunologic reactivities to infectious agents reflect current and past infection, including latent infection unrelated to the cause of the granuloma formation. Histopathologic data more readily support P. acnes as a cause of sarcoidosis compared with M. tuberculosis, suggesting that normally symbiotic P. acnes leads to granuloma formation in some predisposed individuals with Th1 hypersensitivity against intracellular proliferation of latent P. acnes, which may be triggered by certain host or drug-induced conditions. Detection of bacterial nucleic acids in granulomas does not necessarily indicate co-localization of the bacterial proteins in the granulomas. In the histopathologic diagnosis of sarcoidosis, M. tuberculosis-associated and P. acnes-associated sarcoidosis will possibly be differentiated in some patients by immunohistochemistry with appropriate antibodies that specifically react with mycobacterial and propionibacterial antigens, respectively, for each etiology-based diagnosis and potential antimicrobial intervention against sarcoidosis.
Collapse
Affiliation(s)
- Tetsuo Yamaguchi
- Department of Human Pathology, Graduate School and Faculty of Medicine, Tokyo Medical and Dental University, Tokyo 113-8519, Japan; (T.Y.); (K.U.); (K.O.)
- Department of Pulmonology, Shinjuku Tsurukame Clinic, Tokyo 151-0053, Japan
| | - Ulrich Costabel
- Department of Pneumology, Ruhrlandklinik, Medical Faculty, University of Duisburg-Essen, 45239 Essen, Germany;
| | - Andrew McDowell
- Nutrition Innovation Centre for Food and Health (NICHE), School of Biomedical Sciences, Ulster University, Coleraine BT52 1SA, UK;
| | - Josune Guzman
- Department of General and Experimental Pathology, Ruhr University, 44801 Bochum, Germany;
| | - Keisuke Uchida
- Department of Human Pathology, Graduate School and Faculty of Medicine, Tokyo Medical and Dental University, Tokyo 113-8519, Japan; (T.Y.); (K.U.); (K.O.)
| | - Kenichi Ohashi
- Department of Human Pathology, Graduate School and Faculty of Medicine, Tokyo Medical and Dental University, Tokyo 113-8519, Japan; (T.Y.); (K.U.); (K.O.)
| | - Yoshinobu Eishi
- Department of Human Pathology, Graduate School and Faculty of Medicine, Tokyo Medical and Dental University, Tokyo 113-8519, Japan; (T.Y.); (K.U.); (K.O.)
- Correspondence: ; Tel.: +81-90-3332-0948
| |
Collapse
|
5
|
Obi ON, Lower EE, Baughman RP. Biologic and advanced immunomodulating therapeutic options for sarcoidosis: a clinical update. Expert Rev Clin Pharmacol 2021; 14:179-210. [PMID: 33487042 DOI: 10.1080/17512433.2021.1878024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Introduction: Sarcoidosis is a multi-organ disease with a wide range of clinical manifestations and outcomes. A quarter of sarcoidosis patients require long-term treatment for chronic disease. In this group, corticosteroids and cytotoxic agents be insufficient to control diseaseAreas covered: Several biologic agents have been studied for treatment of chronic pulmonary and extra-pulmonary disease. A review of the available literature was performed searching PubMed and an expert opinion regarding specific therapy was developed.Expert opinion: These agents have the potential of treating patients who have progressive disease. Many of these agents have different mechanisms of action, response rates, and toxicity profiles.
Collapse
Affiliation(s)
- Ogugua Ndili Obi
- Division of Pulmonary Critical Care and Sleep Medicine, Brody School of Medicine, East Carolina University, Greenville, NC, USA
| | - Elyse E Lower
- Department of Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | - Robert P Baughman
- Department of Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| |
Collapse
|
6
|
Sawahata M, Sakamoto N, Yamasawa H, Iijima Y, Kawata H, Yamaguchi T, Uchida K, Eishi Y, Bando M, Hagiwara K. Propionibacterium acnes-associated sarcoidosis complicated by acute bird-related hypersensitivity pneumonitis. BMC Pulm Med 2020; 20:288. [PMID: 33160347 PMCID: PMC7649005 DOI: 10.1186/s12890-020-01327-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 10/28/2020] [Indexed: 01/24/2023] Open
Abstract
Background The number of reports on sarcoidosis complicated by hypersensitivity pneumonitis (HP) is limited, and most describe cases complicated by chronic bird-related HP. Here, we present for the first time a case with Propionibacterium acnes-associated sarcoidosis complicated by acute bird-related HP. Case presentation A 62-year-old man with a past medical history of sarcoidosis was admitted to our department, and chest computed tomography showed diffuse ground-glass opacities, which appeared as he rapidly increased the number of pigeons he kept for a competition. Random transbronchial lung biopsy revealed well-formed non-caseating epithelioid granulomas, which contained positively stained substances on immunohistochemistry using the PAB antibody, a specific monoclonal antibody against P. acnes lipoteichoic acid. Poorly formed non-caseating granulomas without positively stained substances were also detected. Conclusion We describe the successful identification of this exceptionally rare case of sarcoidosis complicated by acute bird-related HP in which two morphologically and immunohistologically different types of granulomas were present in the same lung.
Collapse
Affiliation(s)
- Michiru Sawahata
- Division of Pulmonary Medicine, Department of Medicine, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, 329-0498, Japan.
| | - Noritaka Sakamoto
- Division of Pulmonary Medicine, Department of Medicine, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, 329-0498, Japan
| | - Hideaki Yamasawa
- Department of Pulmonary Medicine, International University of Health and Welfare, Nasushiobara, Japan
| | - Yuki Iijima
- Department of Pulmonary Medicine, Tokyo Medical and Dental University Hospital, Tokyo, Japan
| | - Hirotoshi Kawata
- Department of Pathology, Jichi Medical University, Shimotsuke, Japan
| | | | - Keisuke Uchida
- Division of Surgical Pathology, Tokyo Medical and Dental University Hospital, Tokyo, Japan
| | - Yoshinobu Eishi
- Department of Human Pathology, Tokyo Medical and Dental University, Tokyo, Japan
| | - Masashi Bando
- Division of Pulmonary Medicine, Department of Medicine, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, 329-0498, Japan
| | - Koichi Hagiwara
- Division of Pulmonary Medicine, Department of Medicine, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, 329-0498, Japan
| |
Collapse
|
7
|
Amano E, Uchida K, Ishihara T, Otsu S, Machida A, Eishi Y. Propionibacterium acnes-associated chronic hypertrophic pachymeningitis followed by refractory otitis media: a case report. BMC Neurol 2020; 20:11. [PMID: 31918670 PMCID: PMC6953232 DOI: 10.1186/s12883-020-1600-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 01/06/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Hypertrophic pachymeningitis (HP) is a rare disorder that involves localized or diffuse thickening of the dura mater. HP is associated with various inflammatory, infectious, and malignant diseases, such as rheumatic arthritis, sarcoidosis, anti-neutrophil cytoplasmic antibody-associated vasculitis, IgG4-related disorders, syphilis, tuberculosis, bacterial and fungal infections, cancer, and idiopathic diseases, when evaluation fails to reveal a cause. Among them, chronic infection with Propionibacterium acnes is a rare etiology of HP, and its pathology remains unclear. CASE PRESENTATION An 80-year-old man having refractory otitis media with effusion of the right ear presented with progressive right-sided headache and nausea. Post-contrast brain magnetic resonance imaging revealed right mastoiditis and remarkable thickening of the dura mater and enhancement of pia mater extending from the right middle cranial fossa to the temporal lobe. HP secondary to middle ear infection was suspected, and a biopsy of the right mastoid was performed. An anaerobic culture of the biopsied right mastoid showed the growth of P. acnes, and histopathological examination using P. acnes-specific monoclonal antibody (PAB antibody) revealed the infiltration of inflammatory cells with P. acnes. Moreover, using PAB antibody, P. acnes was detected in the biopsy specimen of the thickening dura mater. No granulomas were identified in either specimen. HP was resolved with long-term administration of antibiotics and steroids. CONCLUSION This is the first documentation of pathologically demonstrated chronic HP associated with P. acnes infection followed by refractory otitis media. This report showed that chronic latent P. acnes infection induces chronic inflammation.
Collapse
Affiliation(s)
- Eiichiro Amano
- Department of Neurology, Tsuchiura Kyodo General Hospital, 4-1-1 Otsuno, Tsuchiura-shi, Ibaraki, 300-0028, Japan.
| | - Keisuke Uchida
- Division of Surgical Pathology, Tokyo Medical and Dental University Hospital, 1-5-45 Yushima, Bunkyo, Tokyo, 113-8519, Japan
| | - Tasuku Ishihara
- Department of Neurology, Tsuchiura Kyodo General Hospital, 4-1-1 Otsuno, Tsuchiura-shi, Ibaraki, 300-0028, Japan
| | - Shinichi Otsu
- Department of Neurology, Tsuchiura Kyodo General Hospital, 4-1-1 Otsuno, Tsuchiura-shi, Ibaraki, 300-0028, Japan
| | - Akira Machida
- Department of Neurology, Tsuchiura Kyodo General Hospital, 4-1-1 Otsuno, Tsuchiura-shi, Ibaraki, 300-0028, Japan
| | - Yoshinobu Eishi
- Department of Human Pathology, Graduate School and Faculty of Medicine, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo, 113-8519, Japan
| |
Collapse
|
8
|
Kaiser Y, Eklund A, Grunewald J. Moving target: shifting the focus to pulmonary sarcoidosis as an autoimmune spectrum disorder. Eur Respir J 2019; 54:13993003.021532018. [PMID: 31000677 DOI: 10.1183/13993003.021532018] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Accepted: 04/01/2019] [Indexed: 12/27/2022]
Abstract
Despite more than a century of research, the causative agent(s) in sarcoidosis, a heterogeneous granulomatous disorder mainly affecting the lungs, remain(s) elusive. Following identification of genetic factors underlying different clinical phenotypes, increased understanding of CD4+ T-cell immunology, which is believed to be central to sarcoid pathogenesis, as well as the role of B-cells and other cells bridging innate and adaptive immunity, contributes to novel insights into the mechanistic pathways influencing disease resolution or chronicity. Hopefully, new perspectives and state-of-the-art technology will help to shed light on the still-elusive enigma of sarcoid aetiology. This perspective article highlights a number of recent advances in the search for antigenic targets in sarcoidosis, as well as the main arguments for sarcoidosis as a spectrum of autoimmune conditions, either as a result of an external (microbial) trigger and/or due to defective control mechanisms regulating the balance between T-cell activation and inhibition.
Collapse
Affiliation(s)
- Ylva Kaiser
- Respiratory Medicine Unit, Dept of Medicine, Solna and Center for Molecular Medicine, Karolinska Institutet and Karolinska University Hospital Solna, Stockholm, Sweden
| | - Anders Eklund
- Respiratory Medicine Unit, Dept of Medicine, Solna and Center for Molecular Medicine, Karolinska Institutet and Karolinska University Hospital Solna, Stockholm, Sweden
| | - Johan Grunewald
- Respiratory Medicine Unit, Dept of Medicine, Solna and Center for Molecular Medicine, Karolinska Institutet and Karolinska University Hospital Solna, Stockholm, Sweden
| |
Collapse
|
9
|
Inaoka PT, Shono M, Kamada M, Espinoza JL. Host-microbe interactions in the pathogenesis and clinical course of sarcoidosis. J Biomed Sci 2019; 26:45. [PMID: 31182092 PMCID: PMC6558716 DOI: 10.1186/s12929-019-0537-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 05/22/2019] [Indexed: 12/27/2022] Open
Abstract
Sarcoidosis is a rare inflammatory disease characterized by the development of granulomas in various organs, especially in the lungs and lymph nodes. Clinics of the disease largely depends on the organ involved and may range from mild symptoms to life threatening manifestations. Over the last two decades, significant advances in the diagnosis, clinical assessment and treatment of sarcoidosis have been achieved, however, the precise etiology of this disease remains unknown. Current evidence suggests that, in genetically predisposed individuals, an excessive immune response to unknown antigen/s is crucial for the development of sarcoidosis. Epidemiological and microbiological studies suggest that, at least in a fraction of patients, microbes or their products may trigger the immune response leading to sarcoid granuloma formation. In this article, we discuss the scientific evidence on the interaction of microbes with immune cells that may be implicated in the immunopathogenesis of sarcoidosis, and highlight recent studies exploring potential implications of human microbiota in the pathogenesis and the clinical course of sarcoidosis.
Collapse
Affiliation(s)
- Pleiades T Inaoka
- Department of Physical Therapy, School of Health Sciences, Kanazawa University, Kodatsuno, Kanazawa, 577-8502, Japan
| | - Masato Shono
- Faculty of Medicine, Kindai University, 377-2, Ohno-Higashi, Osaka-Sayama, Osaka, 577-8502, Japan
| | - Mishio Kamada
- Faculty of Medicine, Kindai University, 377-2, Ohno-Higashi, Osaka-Sayama, Osaka, 577-8502, Japan
| | - J Luis Espinoza
- Department of Hematology and Rheumatology, Kindai University Faculty of Medicine, 377-2, Ohno-Higashi, Osaka-Sayama, Osaka, 577-8502, Japan.
| |
Collapse
|