Peroxisome Proliferator-activated Receptor-γ Deficiency Exacerbates Fibrotic Response to Mycobacteria Peptide in Murine Sarcoidosis Model.

We established a murine model of multiwall carbon nanotube (MWCNT)-elicited chronic granulomatous disease that bears similarities to human sarcoidosis pathology, including alveolar macrophage deficiency of peroxisome proliferator-activated receptor γ (PPARγ). Because lymphocyte reactivity to mycobacterial antigens has been reported in sarcoidosis, we hypothesized that addition of mycobacterial ESAT-6 (early secreted antigenic target protein 6) to MWCNT might exacerbate pulmonary granulomatous pathology. MWCNTs with or without ESAT-6 peptide 14 were instilled by the oropharyngeal route into macrophage-specific PPARγ-knockout (KO) or wild-type mice. Control animals received PBS or ESAT-6. Lung tissues, BAL cells, and BAL fluid were evaluated 60 days after instillation. PPARγ-KO mice receiving MWCNT + ESAT-6 had increased granulomas and significantly elevated fibrosis (trichrome staining) compared with wild-type mice or PPARγ-KO mice that received only MWCNT. Immunostaining of lung tissues revealed elevated fibronectin and Siglec F expression on CD11c+ infiltrating alveolar macrophages in the presence of MWCNT + ESAT-6 compared with MWCNT alone. Analyses of BAL fluid proteins indicated increased levels of transforming growth factor (TGF)-ß and the TGF-ß pathway mediator IL-13 in PPARγ-KO mice that received MWCNT + ESAT-6 compared with wild-type or PPARγ-KO mice that received MWCNT. Similarly, mRNA levels of matrix metalloproteinase 9, another requisite factor for TGF-ß production, was elevated in PPARγ-KO mice by MWCNT + ESAT-6. Analysis of ESAT-6 in lung tissues by mass spectrometry revealed ESAT-6 retention in lung tissues of PPARγ-KO but not wild-type mice. These data indicate that PPARγ deficiency promotes pulmonary ESAT-6 retention, exacerbates macrophage responses to MWCNT + ESAT-6, and intensifies pulmonary fibrosis. The present findings suggest that the model may facilitate understanding of the effects of environmental factors on sarcoidosis-associated pulmonary fibrosis.

The composition of the pulmonary microbiota in sarcoidosis - an observational study.

BACKGROUND: Sarcoidosis is a systemic disease of unknown etiology. The disease mechanisms are largely speculative and may include the role microbial patterns that initiate and drive an underlying immune process. The aim of this study was to characterize the microbiota of the lung of patients with sarcoidosis and compare its composition and diversity with the results from patients with other interstitial lung disease (ILD) and historic healthy controls. METHODS: Patients (sarcoidosis, n = 31; interstitial lung disease, n = 19) were recruited within the PULMOHOM study, a prospective cohort study to characterize inflammatory processes in pulmonary diseases. Bronchoscopy of the middle lobe or the lingula was performed and the recovered fluid was immediately sent for analysis of the pulmonary microbiota by 16sRNA gene sequencing. Subsequent bioinformatic analysis was performed to compare the groups. RESULTS: There were no significant differences between patients with sarcoidosis or other ILDs with regard to microbiome composition and diversity. In addition, the abundance of the genera Atopobium, Fusobacterium, Mycobacterium or Propionibacterium were not different between the two groups. There were no gross differences to historical healthy controls. CONCLUSION: The analysis of the pulmonary microbiota based on 16sRNA gene sequencing did not show a significant dysbiosis in patients with sarcoidosis as compared to other ILD patients. These data do not exclude a microbiological component in the pathogenesis of sarcoidosis.

T. marneffei infection complications in an HIV-negative patient with pre-existing pulmonary sarcoidosis: a rare case report.

BACKGROUND: Talaromyces marneffei (T. marneffei) is a thermal dimorphic pathogenic fungus that often causes fatal opportunistic infections in human immunodeficiency virus (HIV)-infected patients. Although T. marneffei-infected cases have been increasingly reported among non-HIV-infected patients in recent years, no cases of T. marneffei infection have been reported in pulmonary sarcoidosis patients. In this case, we describe a T. marneffei infection in an HIV-negative patient diagnosed with pulmonary sarcoidosis. CASE PRESENTATION: A 41-year-old Chinese man who had pre-existing pulmonary sarcoidosis presented with daily hyperpyrexia and cough. Following a fungal culture from bronchoalveolar lavage (BAL), the patient was diagnosed with T. marneffei infection. A high-resolution computed tomography (HRCT) chest scan revealed bilateral lung diffuse miliary nodules, multiple patchy exudative shadows in the bilateral superior lobes and right inferior lobes, air bronchogram in the consolidation of the right superior lobe, multiple hilar and mediastinal lymphadenopathies and local pleural thickening. After 3 mos of antifungal therapy, the patient's pulmonary symptoms rapidly disappeared, and the physical condition improved markedly. A subsequent CT re-examination demonstrated that foci were absorbed remarkably after treatment. The patient is receiving follow-up therapy and assessment for a cure. CONCLUSION: This case suggested that clinicians should pay more attention to non-HIV-related lung infections in patients with pulmonary sarcoidosis. Early diagnosis and treatment with antifungal therapy can improve the prognosis of T. marneffei infection.

Induction of Pulmonary Granuloma Formation by Propionibacterium acnes Is Regulated by MyD88 and Nox2.

Sarcoidosis is characterized by noncaseating granulomas with an unknown cause that present primarily in the lung. Propionibacterium acnes, an immunogenic commensal skin bacterium involved in acne vulgaris, has been implicated as a possible causative agent of sarcoidosis. Here, we demonstrate that a viable strain of P. acnes isolated from a patient with sarcoidosis and instilled intratracheally into wild-type mice can generate pulmonary granulomas similar to those observed in patients with sarcoidosis. The formation of these granulomas is dependent on the administration of viable P. acnes. We also found that mice deficient in the innate immunity adapter protein MyD88 had a greater number and a larger area of granuloma lesions compared with wild-type mice administered P. acnes. Early after P. acnes administration, wild-type mice produced proinflammatory mediators and recruited neutrophils into the lung, a response that is dependent on MyD88. In addition, there was an increase in granuloma number and size after instillation with P. acnes in mice deficient in CybB, a critical component of nicotinamide adenine dinucleotide phosphate oxidase required for the production of reactive oxygen species in the phagosome. Myd88-/- or Cybb-/- mice both had increased persistence of P. acnes in the lung, together with enhanced granuloma formation. In conclusion, we have generated a mouse model of early granuloma formation induced by a clinically relevant strain of P. acnes isolated from a patient with sarcoidosis, and, using this model, we have shown that a deficiency in MyD88 or CybB is associated with impaired bacterial clearance and increased granuloma formation in the lung.

Chronic pulmonary aspergillosis complicating sarcoidosis.

Chronic pulmonary aspergillosis (CPA) complicating sarcoidosis (SA) is associated with high mortality, and there is a lack of clarity regarding the relative contributions of SA or CPA.This was a retrospective single-centre study on CPA-SA.In total, 65 patients (44 men), aged 41.4±13.5 and 48.3±11.9 years at the time of SA and CPA diagnoses, respectively, were included between 1980 and 2015. Of these, 64 had fibrocystic SA, most often advanced, with composite physiological index (CPI) >40 (65% of patients) and pulmonary hypertension (PH) (31%), and 41 patients (63%) were treated for SA (corticosteroids or immunosuppressive drugs). Chronic cavitary pulmonary aspergillosis (CCPA) was the most frequent CPA pattern. Regarding treatment, 55 patients required long-term antifungals, 14 interventional radiology, 11 resection surgery and two transplantation. Nearly half of the patients (27; 41.5%) died (mean age 55.8 years); 73% of the patients achieved 5-year survival and 61% 10-year survival. Death most often resulted from advanced SA and rarely from haemoptysis. CPI, fibrosis extent and PH predicted survival. Comparison with paired healthy controls without CPA did not show any difference in survival, but a higher percentage of patients had high-risk mould exposure.CPA occurs in advanced pulmonary SA. CPA-SA is associated with high mortality due to the underlying advanced SA rather than to the CPA. CPI, fibrosis extent and PH best predict outcome.

High throughput 16SrRNA gene sequencing reveals the correlation between Propionibacterium acnes and sarcoidosis.

OBJECTIVE: This study aims to use high throughput 16SrRNA gene sequencing to examine the bacterial profile of lymph node biopsy samples of patients with sarcoidosis and to further verify the association between Propionibacterium acnes (P. acnes) and sarcoidosis. METHODS: A total of 36 mediastinal lymph node biopsy specimens were collected from 17 cases of sarcoidosis, 8 tuberculosis (TB group), and 11 non-infectious lung diseases (control group). The V4 region of the bacterial 16SrRNA gene in the specimens was amplified and sequenced using the high throughput sequencing platform MiSeq, and bacterial profile was established. The data analysis software QIIME and Metastats were used to compare bacterial relative abundance in the three patient groups. RESULTS: Overall, 545 genera were identified; 38 showed significantly lower and 29 had significantly higher relative abundance in the sarcoidosis group than in the TB and control groups (P < 0.01). P. acnes 16SrRNA was exclusively found in all the 17 samples of the sarcoidosis group, whereas was not detected in the TB and control groups. The relative abundance of P. acnes in the sarcoidosis group (0.16% ± 0. 11%) was significantly higher than that in the TB (Metastats analysis: P = 0.0010, q = 0.0044) and control groups (Metastats analysis: P = 0.0010, q = 0.0038). The relative abundance of P. granulosum was only 0.0022% ± 0. 0044% in the sarcoidosis group. P. granulosum 16SrRNA was not detected in the other two groups. CONCLUSION: High throughput 16SrRNA gene sequencing appears to be a useful tool to investigate the bacterial profile of sarcoidosis specimens. The results suggest that P. acnes may be involved in sarcoidosis development.

Bacteria in a water-damaged building: associations of actinomycetes and non-tuberculous mycobacteria with respiratory health in occupants.

We examined microbial correlates of health outcomes in building occupants with a sarcoidosis cluster and excess asthma. We offered employees a questionnaire and pulmonary function testing and collected floor dust and liquid/sludge from drain tubing traps of heat pumps that were analyzed for various microbial agents. Forty-nine percent of participants reported any symptom reflecting possible granulomatous disease (shortness of breath on exertion, flu-like achiness, or fever and chills) weekly in the last 4 weeks. In multivariate regressions, thermophilic actinomycetes (median = 529 CFU/m2 ) in dust were associated with FEV1 /FVC [coefficient = -2.8 per interquartile range change, P = 0.02], percent predicted FEF25-75% (coefficient = -12.9, P = 0.01), and any granulomatous disease-like symptom [odds ratio (OR) = 3.1, 95% confidence interval (CI) = 1.45-6.73]. Mycobacteria (median = 658 CFU/m2 ) were positively associated with asthma symptoms (OR = 1.5, 95% CI = 0.97-2.43). Composite score (median = 11.5) of total bacteria from heat pumps was negatively associated with asthma (0.8, 0.71-1.00) and positively associated with FEV1 /FVC (coefficient = 0.44, P = 0.095). Endotoxin (median score = 12.0) was negatively associated with two or more granulomatous disease-like symptoms (OR = 0.8, 95% CI = 0.67-0.98) and asthma (0.8, 0.67-0.96). Fungi or (1→3)-ß-D-glucan in dust or heat pump traps was not associated with any health outcomes. Thermophilic actinomycetes and non-tuberculous mycobacteria may have played a role in the occupants' respiratory outcomes in this water-damaged building.

Increased antifungal antibodies in bronchoalveolar lavage fluid and serum in pulmonary sarcoidosis.

The recent studies suggest a role of fungi in development of sarcoidosis. Moreover, the immune response in sarcoidosis and fungal infection shows a striking similarity. We formulated a hypothesis of the possible increase in antifungal antibodies in bronchoalveolar lavage fluid (BALF) and serum in pulmonary sarcoidosis. BALF and serum levels of IgG-, IgM- and IgA-specific antibodies against the cell wall ß-D-glucan and mannan of Candida albicans and Saccharomyces cerevisiae were tested in 47 patients (29 pulmonary sarcoidosis patients and 18 patients with other interstitial lung diseases (ILD - control group)) and 170 healthy controls. Our results proved: (1) an increase in IgG-, IgM- and IgA-specific antifungal antibodies in BALF in pulmonary sarcoidosis compared with the control group (C. albicans: IgG: P = 0.0329, IgM: P = 0.0076, IgA: P = 0.0156; S. cerevisiae: IgG: P = 0.0062, IgM: P = 0.0367, IgA: P = 0.0095) and (2) elevated levels of serum antifungal antibodies in pulmonary sarcoidosis compared with healthy controls (C. albicans: IgG: P = 0.0329, IgM: P = 0.0076, IgA: P = 0.0156; S. cerevisiae: IgG: P > 0.05, IgM: P < 0.05, IgA: P < 0.001). The study showed increased serum and BALF levels of antifungal antibodies in pulmonary sarcoidosis. The hypothesis that fungal infection is one of the possible aetiologic agents of sarcoidosis is interesting and deserves further attention.

Immune response to Propionibacterium acnes in patients with sarcoidosis--in vivo and in vitro.

BACKGROUND: Propionibacterium acnes was found in lungs and lymph nodes of patients with sarcoidosis and may induce hypersensitivity type granuloma formation. Data regarding the immune response to P. acnes of European sarcoid patients are scarce. METHODS: We assessed the total IgG and IgA amount and specific antibodies to P. acnes and to Staphylococcus aureus, serving as a control, in BAL fluid of 64 patients with sarcoidosis and of 21 healthy volunteers. In a subcohort of sarcoid patients and controls, TNF-α and GM-CSF production of BAL cells stimulated with heat-killed P. acnes were measured. RESULTS: In sarcoid patients, the total IgG and IgA levels in BAL fluid were significantly elevated compared to healthy volunteers. IgG and IgA titres against P. acnes and S. aureus were increased in sarcoid patients, yet based on the total amount of antibodies, only antibodies directed against P. acnes were relatively and significantly increased. Furthermore, BAL cells of sarcoid patients produced significantly more TNF-α and GM-CSF upon stimulation with heat-killed P. acnes compared to controls. CONCLUSIONS: Patients with sarcoidosis had elevated levels of specific antibodies against P. acnes which suggest contact with this bacterium in the past. Furthermore, BAL cells of sarcoid patients produced inflammatory cytokines (TNF-α and GM-CSF) upon stimulation with P. acnes indicating potential involvement of this pathogen in the pathogenesis of sarcoidosis in some patients.

Interferon gamma release assays based on M. tuberculosis-specific antigens in sarcoidosis patients.

INTRODUCTION: This study is a part of the project on interferon gamma release assays performed in the group of untreated sarcoidosis patients formerly BCG vaccinated. The aim of the study was to assess the rate of positive commercial interferon g release assays in sarcoidosis patients. We discussed the results in the context of hypothesis that M. tuberculosis antigens may play a role in the pathogenesis of sarcoidosis. MATERIAL AND METHODS: 151 patients, mean age 38 ± 10.3, treatment naive, with newly diagnosed pulmonary sarcoidosis were enrolled into the study. All participants underwent QFT-GIT assay. A subgroup of 81 patients underwent also T-SPOT.TB assay. RESULTS: QFT-GIT was positive in 7/151. T-SPOT.TB was positive in 3/81. There were no indeterminate results in both IGRAs. There was no statistically significant relationship between IGRAs results and sarcoidosis parameters such as the radiologic stage, disease duration and the presence of Löfgren's syndrome. CONCLUSIONS: In sarcoidosis patients formerly BCG vaccinated, positive rate of IGRAs was 4.6% for QFT-GIT and 3.7% for T-SPOT. TB. We did not find the influence of the selected parameters of sarcoidosis on IGRAs results.

Helicobacter pylori infection and respiratory diseases: actual data and directions for future studies.

Helicobacter pylori (H. pylori) has been conclusively related to several gastroduodenal diseases. The possible role of the bacterium in the development of extragastric manifestations has been investigated in the past few years. To identify all publications on the association between H. pylori and respiratory diseases, a MEDLINE search of all studies published in English from 1965 to 2013 was conducted. All data are based on case-control studies. Controversial findings of H. pylori seroprevalence have been obtained in patients with bronchial asthma, lung cancer, pulmonary tuberculosis, sarcoidosis, cystic fibrosis, chronic bronchitis and bronchiectasis. At present, on epidemiological bases, there is no definite evidence of a causal relationship between H. pylori infection and respiratory diseases. There is a low consideration of confounding factors as poorer socioeconomic status and tobacco use. The activation of pro-inflammatory cytokines by H. pylori might be a possible pathogenetic mechanism. However, there are no convincing data about the influence of H. pylori on the inflammatory changes of the bronchoepithelium so far. Further studies are needed on the impact of H. pylori eradication, on the prevention, development and natural history of these disorders.

Microbial communities in the respiratory tract of patients with interstitial lung disease.

BACKGROUND: Molecular methods based on phylogenetic differences in the 16S rRNA gene are able to characterise the microbiota of the respiratory tract in health and disease. OBJECTIVES: Our goals were (1) to characterise bacterial communities in lower and upper airways of patients with interstitial lung disease (ILD) and (2) to compare the results with the microbiota of patients with Pneumocystis pneumonia (PCP) and normal controls. METHODS: We examined the upper and lower respiratory tract of 18 patients with ILD of whom 5, 6, and 7 had idiopathic interstitial pneumonia (IIP), non-IIP and sarcoidosis, respectively. In addition, six immune-compromised patients with PCP and nine healthy subjects were included as controls. Exclusion criteria were recent bacterial/viral respiratory tract infection, HIV-positivity and subjects receiving antibiotic therapy. Bronchoalveolar lavage fluid and oropharyngeal swabs were simultaneously collected, and microbiota was characterised by ultra-deep 16S rRNA gene sequencing. RESULTS: The microbiota in lower airways of the majority of patients (30; 90%) primarily consisted of Prevotellaceae, Streptococcaceae and Acidaminococcaceae. α and ß diversity measurements revealed no significant differences in airway microbiota composition between the five different groups of patients. Comparison of bacterial populations in upper and lower respiratory tract showed significant topographical discontinuities for 7 (23%) individuals. CONCLUSIONS: IIP, non-IIP and sarcoidosis are not associated with disordered airway microbiota and a pathogenic role of commensals in the disease process is therefore unlikely. Nevertheless, molecular analysis of the topographical microbiota continuity along the respiratory tract may provide additional information to assist management of individual patients.

Localization of propionibacterium acnes in granulomas supports a possible etiologic link between sarcoidosis and the bacterium.

Sarcoidosis likely results from the exposure of a genetically susceptible subject to an environmental agent, possibly an infectious one. Mycobacterial and propionibacterial organisms are the most commonly implicated potential etiologic agents. Propionibacterium acnes is the only microorganism, however, found in sarcoid lesions by bacterial culture. To evaluate the pathogenic role of this indigenous bacterium, we screened for the bacterium in sarcoid and non-sarcoid tissues using immunohistochemical methods with novel P. acnes-specific monoclonal antibodies that react with cell-membrane-bound lipoteichoic acid (PAB antibody) and ribosome-bound trigger-factor protein (TIG antibody). We examined formalin-fixed and paraffin-embedded samples of lungs and lymph nodes from 196 patients with sarcoidosis, and corresponding control samples from 275 patients with non-sarcoidosis diseases. The samples were mostly from Japanese patients, with 64 lymph node samples from German patients. Immunohistochemistry with PAB antibody revealed small round bodies within sarcoid granulomas in 20/27 (74%) video-assisted thoracic surgery lung samples, 24/50 (48%) transbronchial lung biopsy samples, 71/81 (88%) Japanese lymph node samples, and 34/38 (89%) German lymph node samples. PAB antibody did not react with non-sarcoid granulomas in any of the 45 tuberculosis samples or the 34 samples with sarcoid reaction. In nongranulomatous areas, small round bodies detected by PAB antibody were found in alveolar macrophages of lungs and paracortical macrophages of lymph nodes from many sarcoid and some non-sarcoid patients. Large-spheroidal acid-fast bodies, Hamazaki-Wesenberg bodies, which were found in 50% of sarcoid and 15% of non-sarcoid lymph node samples, reacted with both PAB and TIG antibodies. Electron microscopy revealed that these Hamazaki-Wesenberg bodies had a single bacterial structure and lacked a cell wall with occasional protrusions from the body. The high frequency and specificity of P. acnes, detected by PAB antibody within sarcoid granulomas, indicates that this indigenous bacterium might be the cause of granuloma formation in many sarcoid patients.

[Complex morphological diagnostics of tuberculosis and sarcoidosis of the lungs].

Differential diagnosis of disseminated lung diseases, particularly tuberculosis and sarcoidosis, presents certain difficulties for clinicians. In the verification of the diagnosis a decisive role belongs to the morphological study, for which the most commonly used material is transbronchial biopsy. Diagnostic signs of active disseminated pulmonary tuberculosis are presence of different-sized granulomas with signs merger, necrosis, infiltration of polymorphonuclear leukocytes, weakly expressed fibrillogenesis. Cytological markers of a specific process are young biosinteziruyuschie macrophages and acid-fast bacilli. The diagnostic features of pulmonary sarcoidosis are monomorphic granulomas with no tendency to merge and necrotisation expressed fibrosis and hyalinization processes. Cytological marker for the disease is the high content of epithelioid cells with signs of secretion.

Phase II Investigation of the Efficacy of Antimycobacterial Therapy in Chronic Pulmonary Sarcoidosis.

BACKGROUND: A Phase I, single-center investigation found that 8 weeks of antimycobacterial therapy improved sarcoidosis FVC. Safety and efficacy assessments have not been performed in a multicenter cohort. RESEARCH QUESTION: The objective of this study was to determine the safety and efficacy of antimycobacterial therapy on the physiological and immunologic end points of sarcoidosis. STUDY DESIGN AND METHODS: In a double-blind, placebo-controlled, multicenter investigation, patients with pulmonary sarcoidosis were randomly assigned to receive 16 weeks of concomitant levofloxacin, ethambutol, azithromycin, and rifabutin (CLEAR) or matching placebo to investigate the effect on FVC. The primary outcome was a comparison of change in percentage of predicted FVC among patients randomized to receive CLEAR or placebo in addition to their baseline immunosuppressive regimen. Secondary outcomes included 6-min walk distance (6MWD), St. George's Respiratory Questionnaire (SGRQ) score, adverse events, and decrease in mycobacterial early secreted antigenic target of 6 kDa (ESAT-6) immune responses. RESULTS: The intention-to-treat analysis revealed no significant differences in change in FVC among the 49 patients randomized to receive CLEAR (1.1% decrease) compared with the 48 randomized to receive placebo (0.02% increase) (P = .64). Physiological parameters such as the change in 6MWD were likewise similar (P = .91); change in SGRQ favored placebo (-8.0 for placebo vs -1.5 for CLEAR; P = .028). The per-protocol analysis revealed no significant change in FVC at 16 weeks between CLEAR and placebo. There was no significant change in 6MWD (36.4 m vs 6.3 m; P = .24) or SGRQ (-2.3 vs -7.0; P = .14). A decline in ESAT-6 immune responses at 16 weeks was noted among CLEAR-treated patients (P = .0003) but not patients receiving placebo (P = .24). INTERPRETATION: Despite a significant decline in ESAT-6 immune responses, a 16-week CLEAR regimen provided no physiological benefit in FVC or 6MWD among patients with sarcoidosis.

IL-17A Can Promote Propionibacterium acnes-Induced Sarcoidosis-Like Granulomatosis in Mice.

The etiology of sarcoidosis is unknown. In this study, Propionibacterium acnes (PA) was used to induce sarcoidosis-like granulomatous inflammation in a mouse model. Wild-Type (WT) C57BL/6 mice were divided into three groups: (1) WT-PA group; (2) WT-PA + Incomplete Freund's Adjuvant (IFA) group; and (3) WT-PBS group. Loose granuloma formation was observed in the lungs on day 56 in the WT-PA and WT-PA + IFA groups. The proportions of peripheral Th17 cells in the WT-PA (p = 0.0004) and WT-PA + IFA groups (p = 0.0005) were significantly higher than that in the WT-PBS group. The proportions of peripheral Treg cells in the WT-PA (p < 0.0001) and WT-PA + IFA groups (p < 0.0001) were lower than that in the WT-PBS group. Then, to explore the mechanism of IL-17, Wild-Type (WT) C57BL/6 mice were divided into three groups: (1) WT-PBS group (2) WT-PA group; (3) WT-PA + mouse IL-17A neutralizing antibody (IL-17Ab) group. IL-17A gene knockout mice (KO) were divided into two groups: (1) KO -PA group; (2) KO-PBS group. The KO-PA and WT-PA + IL-17Ab groups showed reduced inflammation and no loose granuloma formation on day 56. As compared to the WT-PA group, the ratio of peripheral Th17 in the KO-PA (p < 0.0001) and WT-PA + IL-17Ab groups (p < 0.0001) decreased, while the ratio of peripheral Treg in the KO-PA (p < 0.0001) and WT-PA + IL-17Ab (p = 0.0069) groups increased on day 56. Hence, PA can be used to establish a mouse model of sarcoidosis-like granuloma. IL-17A plays an important role in experimental sarcoidosis-like granuloma formation.

Quantitative analysis of propionibacterial DNA in bronchoalveolar lavage cells from patients with sarcoidosis.

BACKGROUND AND AIM OF THE WORK: The causes of sarcoidosis are still unknown. Propionibacterial subspieces are thought to be one of the most likely sources of antigens. Here we attempted to measure the amount of propionibacterial DNA in bronchoalveolar lavage (BAL) cell samples from patients with sarcoidosis and other pulmonary diseases. METHODS: We examined BAL cells from 42 patients with sarcoidosis and 30 controls. Using quantitative polymerase chain reaction (PCR) for 16S rRNA of Propionibacterium acnes (P. acnes) and Propionibacterium granulosum (P. granulosum), we measured the amount of propionibacterial DNA in 500 ng of total DNA extracted from BAL cells from patients with sarcoidosis or other lung diseases. The correlation between clinical findings and the results of quantitative PCR were analyzed. RESULTS: The mean level of P. acnes DNA from patients with sarcoidosis was 59.9 genomes per 500 ng of total DNA, which was significantly higher than that in controls (20.7 genomes, p<0.000l). The mean level of P. granulosum DNA from patients with sarcoidosis was 1.2 genomes, which was similar to that in controls (1.0 +/-1.6 genomes, p=0.52). The number of genomes of P. acnes in BAL cells was correlated with the serum angiotensin-converting enzyme (ACE) level and the percentage of macrophages in BAL fluid from patients with sarcoidosis. CONCLUSIONS: The amount of P. acnes DNA in BAL cells from patients with sarcoidosis was significantly higher than that in BAL cells from patients with other pulmonary diseases. P. acnes may be involved in the pathogenesis of sarcoidosis.

Use of the QuantiFERON-TB Gold test in Japanese patients with sarcoidosis.

BACKGROUND AND OBJECTIVE: Mycobacterium tuberculosis has been proposed as a candidate agent for the cause of sarcoidosis. The QuantiFERON-TB Gold test has a higher specificity for detecting M. tuberculosis infection than the conventional tuberculin skin test. This study aimed to investigate the rate of positive QuantiFERON-TB Gold results in Japanese sarcoidosis patients. PATIENTS AND METHODS: The QuantiFERON-TB Gold test, an enzyme-linked immunosorbent assay, was used to assess the levels of interferon-gamma resulting from immune responses to M. tuberculosis-specific antigens, namely early secretory antigen target 6 and culture filtrate protein 10, in 90 Japanese sarcoidosis patients. RESULTS: The QuantiFERON-TB Gold result was positive in 3 of the 90 patients tested. CONCLUSION: The positivity rate of QuantiFERON-TB Gold was 3.3% in Japanese sarcoidosis patients.