Etiology of Sarcoidosis

Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, 5501 Hopkins Bayview Circle, Baltimore, MD 21224, USA.
Clinics in Chest Medicine (Impact Factor: 2.07). 10/2008; 29(3):365-77, vii. DOI: 10.1016/j.ccm.2008.03.011
Source: PubMed


Research over the past decade has advanced our understanding of the pathogenesis of sarcoidosis and provided new insights into potential causes of this disease. It is important to remember that any etiologic agent of sarcoidosis must be capable of causing the pathologic hallmark of systemic noncaseating granulomas and the heterogeneous clinical features of sarcoidosis. In addition, etiologic agents must be compatible with immunologic features, including polarized T-helper 1 cytokine profiles and oligoclonal T cell expansions consistent with antigen driven processes. Yet, even with studies conducted in this disease, there remains a lack of consensus on the etiology of sarcoidosis. This challenge is likely to be overcome only with additional research that incorporates clinical, genetic, immunologic, environmental, and microbiologic profiles in groups of patients, supplemented with testing of candidate pathogenic agents in experimental models that recapitulate critical features of this disease.

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    • "Although the exact pathogenesis of sarcoidosis is not known, it is currently accepted that, in genetically susceptible individuals, it is caused through alteration of the cellular immune response after exposure to an environmental, occupational, or infectious agent [2]. Accumulations of Th1 and macrophages with increased production of proinflammatory cytokines induce the inflammatory cascade and consecutive impairment in tissue permeability; increase in cellular influx and local cellular proliferation cause the formation of granulomas [3]. The crucial pathological finding of sarcoidosis is noncalcified epitheloid cellular granulomas [4]. "
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    ABSTRACT: Introduction. Sarcoidosis is a chronic granulomatous disease, which can involve different organs and systems. Coexistence of sarcoidosis and spondyloarthritis has been reported in numerous case reports. Purpose. To determine the prevalence of sacroiliitis and spondyloarthritis in patients previously diagnosed with sarcoidosis and to investigate any possible relation with clinical findings. Materials and Methods. Forty-two patients with sarcoidosis were enrolled in the study. Any signs and symptoms in regard to spondyloarthritis (i.e., existence of inflammatory back pain, gluteal pain, uveitis, enthesitis, dactylitis, inflammatory bowel disease, and psoriasis) were questioned in detail and biochemical tests were evaluated. Sacroiliac joint imaging and lateral heel imaging were performed in all patients. Results. Sacroiliitis was found in 6 of the 42 (14.3%) sarcoidosis patients and all of these patients were female. Common features of the disease in these six patients were inflammatory back pain as the major clinical complaint, stage 2 sacroiliitis as revealed by radiological staging, and the negativity of HLA B-27 test. These six patients with sacroiliitis were diagnosed with spondyloarthritis according to the criteria of ASAS and of ESSG. Conclusion. We found spondyloarthritis in patients with sarcoidosis at a higher percentage rate than in the general population (1-1.9%). Controlled trials involving large series of patients are required for the confirmation of the data.
    Full-text · Article · May 2014 · International Journal of Rheumatology
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    • "Löfgren syndrome is an acute sarcoidosis presentation characterized by arthritis/arthralgia, erythema nodosum (EN), and bilateral hilar lymphadenopathy. Although its pathogenesis in not clear, there appears to be a cellular immune system activation and a nonspecific inflammatory response against some genetic and environmental factors [2]. Th1-lymphocyte and macrophages caused by proinflammatory cytokines induce the inflammatory cascade and the formations of granulomas occur as a result of tissue permeability, cellular influx, and local cell proliferation [3]. "
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    ABSTRACT: A 46-year-old male patient diagnosed with ankylosing spondylitis presented to our polyclinic with complaints of pain, swelling, and limitation in joint mobility in both ankles and erythema nodosum skin lesions in both pretibial sites. The sacroiliac joint graphy and the MRI taken revealed active and chronic sacroiliitis. On the thorax CT, multiple mediastinal and hilar lymphadenopathies were reported. Mediastinoscopic excisional lymph node biopsy was taken and noncalcified granulomatous structures, lymphocytes, and histiocytes were determined on histopathological examination. The patients were diagnosed with ankylosing spondylitis, sarcoidosis, and Löfgren's syndrome. NSAIDs, sulfasalazine, and low dose corticosteroid were started. Significant regression was seen in the patient's subjective and laboratory assessments.
    Full-text · Article · Mar 2014
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    • "and granulomas are formed as a result of tissue permeability, cellular influx and local cell proliferation [Chen and Moller, 2008]. Identification of noncaseating epithelioid cell granulomas is an essential pathological finding in sarcoidosis [Smith et al. 2008]. "
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    ABSTRACT: Sarcoidosis is known as a T helper 1 lymphocyte (Th1-Ly) mediated disease which can imitate or sometimes accompany many primary rheumatic diseases. The purpose of this study is to share the clinical, demographic and laboratory data of patients presenting with rheumatologic manifestations and diagnosed with sarcoidosis. A total of 42 patients (10 men) were included in the study. The patients were admitted to the rheumatology outpatient clinic for the first time with different rheumatic complaints between November 2011 and May 2013 and were diagnosed with sarcoidosis after relevant tests. Clinical, demographic, laboratory, radiological and histological data of these patients were collected during the 18-month follow-up period and then analyzed. Mean patient age was 45.2 years (20-70 years) and mean duration of disease was 3.5 years (1 month-25 years). Evaluation of system and organ involvement revealed that 20 (47.6%) patients had erythema nodosum, 3 (7.1%) had uveitis, 1 (2.3%) had myositis, 1 (2.3%) had neurosarcoidosis, 32 (76.2%) had arthritis and 40 (95.2%) had arthralgia. Of the 32 patients with arthritis, 28 (87.5%) had involvement of the ankle, 3 (9.4%) had involvement of the knee and 1 (3.2%) had involvement of the wrist. No patient had cardiac involvement. Thoracic computed tomography scan showed stage 1, 2, 3 and 4 sarcoidosis in 12 (28.5%), 22 (52.4%), 4 (9.5%) and 4 (9.5%) patients, respectively. Histopathology of sarcoidosis was verified by endobronchial ultrasound, mediastinoscopy and skin and axillary biopsy of lymphadenopathies, which revealed noncaseating granulomas. Laboratory tests showed elevated serum angiotensin-converting enzyme in 15 (35.7%) patients, elevated serum calcium level in 6 (14.2%) patients and elevated serum 1,25-dihydroxyvitamin D concentrations in 2 (4.7%) patients. Serological tests showed antinuclear antibody positivity in 12 (28.5%) patients, rheumatoid factor positivity in 7 (16.6%) patients and anticyclic citrullinated antibody positivity in 2 (4.8%) patients. Sarcoidosis can imitate or accompany many primary rheumatic diseases. Sarcoidosis should be considered not simply as an imitator but as a primary rheumatic pathology mediated by Th1-Ly. New studies are warranted on this subject.
    Full-text · Article · Feb 2014 · Therapeutic advances in musculoskeletal disease
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