Increased proportions of circulating PD-1+ CD4+ memory T cells and PD-1+ regulatory T cells associate with good response to prednisone in pulmonary sarcoidosis.

BACKGROUND: The treatment response to corticosteroids in patients with sarcoidosis is highly variable. CD4+ T cells are central in sarcoid pathogenesis and their phenotype in peripheral blood (PB) associates with disease course. We hypothesized that the phenotype of circulating T cells in patients with sarcoidosis may correlate with the response to prednisone treatment. Therefore, we aimed to correlate frequencies and phenotypes of circulating T cells at baseline with the pulmonary function response at 3 and 12 months during prednisone treatment in patients with pulmonary sarcoidosis. METHODS: We used multi-color flow cytometry to quantify activation marker expression on PB T cell populations in 22 treatment-naïve patients and 21 healthy controls (HCs). Pulmonary function tests at baseline, 3 and 12 months were used to measure treatment effect. RESULTS: Patients with sarcoidosis showed an absolute forced vital capacity (FVC) increase of 14.2% predicted (± 10.6, p < 0.0001) between baseline and 3 months. Good response to prednisone (defined as absolute FVC increase of ≥ 10% predicted) was observed in 12 patients. CD4+ memory T cells and regulatory T cells from patients with sarcoidosis displayed an aberrant phenotype at baseline, compared to HCs. Good responders at 3 months had significantly increased baseline proportions of PD-1+CD4+ memory T cells and PD-1+ regulatory T cells, compared to poor responders and HCs. Moreover, decreased fractions of CD25+ cells and increased fractions of PD-1+ cells within the CD4+ memory T cell population correlated with ≥ 10% FVC increase at 12 months. During treatment, the aberrantly activated phenotype of memory and regulatory T cells reversed. CONCLUSIONS: Increased proportions of circulating PD-1+CD4+ memory T cells and PD-1+ regulatory T cells and decreased proportions of CD25+CD4+ memory T cells associate with good FVC response to prednisone in pulmonary sarcoidosis, representing promising new blood biomarkers for prednisone efficacy. TRIAL REGISTRATION: NL44805.078.13.

Follicular Helper-like T Cells in the Lung Highlight a Novel Role of B Cells in Sarcoidosis.

Rationale: Pulmonary sarcoidosis is generally presumed to be a T-helper cell type 1- and macrophage-driven disease. However, mouse models have recently revealed that chronically inflamed lung tissue can also comprise T follicular helper (Tfh)-like cells and represents a site of active T-cell/B-cell cooperation. Objectives: To assess the role of pulmonary Tfh- and germinal center-like lymphocytes in sarcoidosis. Methods: BAL fluid, lung tissue, and peripheral blood samples from patients with sarcoidosis were analyzed by flow cytometry, immunohistology, RNA sequencing, and in vitro T-cell/B-cell cooperation assays for phenotypic and functional characterization of germinal center-like reactions in inflamed tissue. Measurements and Main Results: We identified a novel population of Tfh-like cells characterized by high expression of the B helper molecules CD40L and IL-21 in BAL of patients with sarcoidosis. Transcriptome analysis further confirmed a phenotype that was both Tfh-like and tissue resident. BAL T cells provided potent help for B cells to differentiate into antibody-producing cells. In lung tissue, we observed large peribronchial infiltrates with T and B cells in close contact, and many IgA+ plasmablasts. Most clusters were nonectopic; that is, they did not contain follicular dendritic cells. Patients with sarcoidosis also showed elevated levels of PD-1high CXCR5- CD40Lhigh ICOShigh Tfh-like cells, but not classical CXCR5+ Tfh cells, in the blood. Conclusions: Active T-cell/B-cell cooperation and local production of potentially pathogenic antibodies in the inflamed lung represents a novel pathomechanism in sarcoidosis and should be considered from both diagnostic and therapeutic perspectives.

Association of proangiogenic and profibrotic serum markers with lung function and quality of life in sarcoidosis.

BACKGROUND: Sarcoidosis is a systemic inflammatory granulomatous disease, frequently affecting the lung. If left untreated, it may end in lung fibrosis. Proangiogenic and profibrotic vascular endothelial growth factor (VEGF), transforming growth factor (TGF)-ß1, fibroblast growth factor (FGF)-2 and platelet-derived growth factor (PDGF)-AB are a known therapeutical target in pulmonary fibrosing diseases, e.g. IPF, but there is no targeted therapy option for pulmonary fibrosis in sarcoidosis. OBJECTIVES: The aim of our study was to determine the association of these markers' serum levels on lung function and the patients' quality of life in a long-term follow-up of sarcoidosis patients, to provide further information for finding targeted therapy options for pulmonary sarcoidosis. METHODS: 54 patients with sarcoidosis underwent blood sampling, pulmonary function testing and answered the King's Brief Interstitial Lung Disease (K-BILD) questionnaire at baseline and at three-years follow-up. Serum levels of profibrotic and angiogenic markers were assessed at baseline by enzyme-linked immunosorbent assay. RESULTS: Between 2015 and 2018, 54 patients with biopsy proven sarcoidosis were enrolled. Throughout the observation period, there was a significant decrease in the diffusion capacity for carbon monoxide (DLCO) [%] (-6.5504 ± 13,39, p = 0.001) and forced expiratory volume in one second predicted (FEV1) [%] (-6.07 ± 12.09, p = 0.001). Patients with greater impairment of forced vital capacity (FVC) did have significantly higher serum levels of VEGF (p = 0.03) and PDGF-AB (p<0.001). The K-BILD questionnaire did not change significantly during follow-up. However, patients with worsening K-BILD scores did have significantly higher serum-levels of PDGF-AB (2.67 pg/ml ± 0.93 vs. 1.88 pg/ml ± 0.60, p = 0.004) at baseline, compared to those with unchanged or increasing K-BILD scores. CONCLUSIONS: Among patients with pulmonary sarcoidosis, baseline serum levels of VEGF and PDGF-AB were associated with pulmonary function impairment. Furthermore, PDGF-AB was associated with worsening K-BILD scores. No such association was observed for FGF-2 and TGF-ß1. VEGF and PDGF-AB may be possible prognostic and therapeutic targets in sarcoidosis as a fibrosing ILD beyond IPF.

Soluble interleukin-2 receptor in exhaled breath condensate in pulmonary sarcoidosis: a cross-sectional pilot study.

INTRODUCTION: Sarcoidosis is a chronic granulomatous disease of unknown aetiology with a variable clinical course and prognosis. There is an urgent need to identify new and novel biomarkers to help differentiate between clinical phenotypes and guide clinical decisions with respect to commencing and monitoring treatment. Across the spectrum of respiratory disease there has been a growing interest in the role of breath-based biomarkers given their non-invasive nature and ability to repeat sampling with ease for serial monitoring. Soluble interleukin-2 receptor (sIL2R) in bronchoalveolar lavage and serum correlates with disease activity in sarcoidosis; however, no previous study has evaluated sIL2R in exhaled breath. OBJECTIVES: The main aim of this cross-sectional case-controlled pilot study was to determine the concentration of sIL2R in exhaled breath condensate (EBC) from patients with recently diagnosed sarcoidosis compared to healthy volunteers and to establish, if present, if this correlated with markers of disease activity, pulmonary function tests and serological markers used in current clinical practice. METHODS: Paired serum and EBC samples were collected from twelve treatment naïve patients with histologically proven sarcoidosis diagnosed during the previous six months and compared to twelve healthy volunteers matched for age and gender. RESULTS: Mean concentration of serum sIL2R was significantly elevated in participants with sarcoidosis compared to healthy controls (1584.3 ± 489.1 versus 874.2 ± 235.7 pg mL-1; p = 0.001). Soluble interleukin-2 receptor in EBC was detectable in only five subjects including three participants with sarcoidosis. The range of sIL2R across all five samples was 148.0-288.2 pg mL-1 with the two highest concentrations observed in two participants with sarcoidosis. There was no significant difference observed in EBC sIL2R between sarcoidosis and healthy controls (p = 0.71). No apparent correlations were observed between EBC sIL2R and radiological stage, pulmonary function tests or serological markers. CONCLUSION: Soluble interleukin-2 receptor is detectable in EBC; however, the findings from our study do not support its role as a diagnostic marker in sarcoidosis. Further research is required to evaluate its prognostic utility.

Role of fibrocytes and endothelial progenitor cells among low-differentiated CD34+ cells in the progression of lung sarcoidosis.

BACKGROUND: Sarcoidosis is a multisystemic granulomatous disease with still unknown etiology. Our previous studies showed a significantly higher percentage of CD34 + cells in the peripheral blood in patients with sarcoidosis (SA) compared to the control group. The objective of the present study was to characterized of the CD34 + cell population in peripheral blood in patients with SA with reference to the control group. Moreover in patients with SA, fibrocytes and endothelial cells were analysed and their relationship to the fibrosis process based on assessment of diffusing capacity for carbon monoxide (DLCO). METHODS: Data from patients diagnosed with SA at Military Institute of Medicine (Warsaw, Poland) between January 2018 and December 2019 were collected and analysed ongoing basis. Peripheral blood was collected from 26 patients with newly diagnosed pulmonary SA and 16 healthy subjects. The immunomagnetic method and flow cytometry were used. Among the CD34+ progenitor cells were assessed: low-differentiated cells, hematopoietic progenitor cells and endothelial progenitor cells. The Statistica 12.0 software was used for a statistical analysis. RESULTS: We observed a significantly higher percentage of low-differentiated cells (13.8 vs. 2.3, P = 0.001) and endothelial cells (0.3 vs. 0.0, P = 0.001) in patients with SA compared to the control group. In the study group the median proportion of fibrocytes was 1.877% (0.983-2.340) in patients with DLCO< 80%, while in patients with DLCO> 80% was 0.795% (0.139-1.951) (P = 0.72). The median proportion of endothelial progenitor cells was higher in patients with DLCO< 80%: 0.889% (0.391-1.741), than in patients with DLCO> 80%: 0.451% (0.177-0.857) (P = 0.44). CONCLUSIONS: In conclusion we demonstrated for the first time the immunophenotype of peripheral CD34 + cells with the degree of their differentiation. The study confirmed the involvement of low differentiated cells and endothelial cells in patients with SA.

The Association of Neutrophil/Lymphocyte and Platelet/Lymphocyte Ratios and Hematological Parameters with Diagnosis, Stages, Extrapulmonary Involvement, Pulmonary Hypertension, Response to Treatment, and Prognosis in Patients with Sarcoidosis.

Sarcoidosis is a rare disease characterized by granulomatous inflammation in affected organs, primarily in lungs. Neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR) are easy and practical methods providing valuable information in diagnosis, severity, and prognosis of various diseases. Here, we aimed to investigate the association between NLR, PLR, and hematological parameters in sarcoidosis. The study was performed with 75 sarcoidosis patients and 92 controls. Patients' NLR, PLR, and hematological parameters were compared with those of controls. Additionally, while differences between NLR and PLR were investigated in sarcoidosis patients, differences of extrapulmonary involvement, pulmonary hypertension (PH), and spontaneous remission between those with and without responses to treatment concerning stages were also assessed. NLR and PLR were significantly higher in sarcoidosis patients than controls. For NLR, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were found as 68, 61, 58, and 70% respectively, while sensitivity, specificity, PPV, and NPV for PLR were found as 72, 67, 63, and 74%, respectively. In sarcoidosis patients, NLR and PLR were significantly higher at stage-2 and -3 than at stage -1 and -4. There was a significant weak positive correlation between C-reactive protein (CRP) and NLR and PLR. Mean platelet volume (MPV), hemoglobin (Hgb), and mean corpuscular volume (MCV) were lower among patients than controls. A positive moderate correlation was detected between NLR and CD4/CD8 in blood, while there was a strong positive correlation between CD4/CD8 in bronchoalveolar lavage (BAL) and positive moderate correlation between PLR and CD4/CD8 in BAL. High NLR and PLR values were not significantly associated with pulmonary PH, spontaneous remission, response to treatment, and prognosis. The increase in PLR and NLR may be a guide for diagnoses of both sarcoidosis and lung parenchymal involvement. To use these entities as markers, our findings should be supported with prospective studies with larger samples.

Serum soluble interleukin-2 receptor level is a predictive marker for EBUS-TBNA-based diagnosis of sarcoidosis.

BACKGROUND: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a widely available diagnostic tool for suspected stage I/II sarcoidosis. Combination of EBUS-TBNA and transbronchial lung biopsy (TBLB) has been proposed as diagnostic procedure in clinical settings. OBJECTIVES: The aim of this study was to assess the diagnostic yield of combined EBUS-TBNA and TBLB and identify the markers correlated with a high diagnostic rate. METHODS: We retrospectively analyzed the data of 37 patients with suspected stage I/II sarcoidosis with enlarged hilar or mediastinal lymph nodes on computed tomography (CT) images. These patients had been scheduled to undergo EBUS-TBNA and TBLB. Serum levels of sarcoidosis markers (angiotensin-converting enzyme [ACE], soluble interleukin-2 receptor [sIL-2R], and lysozyme), CT findings, and examination techniques were evaluated as predictive markers for diagnosis. RESULTS: Of the 37 patients, 32 had undergone both EBUS-TBNA and TBLB, while the remaining 5 patients had only undergone EBUS-TBNA. The diagnosis was confirmed by TBLB in 16 of the 32 patients (50.0%), EBUS-TBNA in 31 of the 37 patients (83.8%), and combined TBLB and EBUS-TBNA in all patients (100.0%). The serum level of sIL-2R, but not that of ACE or lysozyme, was correlated with successful diagnosis by EBUS-TBNA. CONCLUSION: In patients with stage I/II sarcoidosis, the serum level of sIL-2R is a promising and useful marker for predicting the diagnosis by EBUS-TBNA and reducing the burden of additional TBLB and its possible complications. (Sarcoidosis Vasc Diffuse Lung Dis 2020; 37 (1): 8-16).

Age-associated B Cells Appear in Patients with Granulomatous Lung Diseases.

Rationale: A subpopulation of B cells (age-associated B cells [ABCs]) is increased in mice and humans with infections or autoimmune diseases. Because depletion of these cells might be valuable in patients with certain lung diseases, the goal was to find out if ABC-like cells were at elevated levels in such patients.Objectives: To measure ABC-like cell percentages in patients with lung granulomatous diseases.Methods: Peripheral blood and BAL cells from patients with sarcoidosis, beryllium sensitivity, or hypersensitivity pneumonitis and healthy subjects were analyzed for the percentage of B cells that were ABC-like, defined by expression of CD11c, low levels of CD21, FcRL 1-5 (Fc receptor-like protein 1-5) expression, and, in some cases, T-bet.Measurements and Main Results: ABC-like cells in blood were at low percentages in healthy subjects and higher percentages in patients with sarcoidosis as well as at high percentages among BAL cells of patients with sarcoidosis, beryllium disease, and hypersensitivity pneumonitis. Treatment of patients with sarcoidosis led to reduced percentages of ABC-like cells in blood.Conclusions: Increased levels of ABC-like cells in patients with sarcoidosis may be useful in diagnosis. The increase in percentage of ABC-like cells in patients with lung granulomatous diseases and decrease in treated patients suggests that depletion of these cells may be valuable.

Remarkable Improvement in Clinical Course and Serum KL-6 Levels after Initiation of High-Dose Inhaled Budesonide in Pulmonary Sarcoidosis.

We present a pulmonary sarcoidosis patient with specific elevation of serum Krebs von den lungen-6 (KL-6) levels, who was successfully treated with inhaled corticosteroids. Pulmonary sarcoidosis was initially identified as a chest radiograph abnormality during a routine medical examination, and subsequently confirmed by a high serum level of soluble interleukin 2 receptor. The patient was started on high-dose inhaled budesonide because of high serum levels of angiotensin-converting enzyme (ACE) and KL-6. Following treatment, radiographic findings improved, ACE levels normalized, and serum KL-6 levels markedly decreased. No recurrence was detected at 100 months with a budesonide dosage of 800 µg/day. This case demonstrates the efficacy of highdose inhaled corticosteroids for the initial treatment of pulmonary sarcoidosis.

Diagnosis and Detection of Sarcoidosis. An Official American Thoracic Society Clinical Practice Guideline.

Background: The diagnosis of sarcoidosis is not standardized but is based on three major criteria: a compatible clinical presentation, finding nonnecrotizing granulomatous inflammation in one or more tissue samples, and the exclusion of alternative causes of granulomatous disease. There are no universally accepted measures to determine if each diagnostic criterion has been satisfied; therefore, the diagnosis of sarcoidosis is never fully secure.Methods: Systematic reviews and, when appropriate, meta-analyses were performed to summarize the best available evidence. The evidence was appraised using the Grading of Recommendations, Assessment, Development, and Evaluation approach and then discussed by a multidisciplinary panel. Recommendations for or against various diagnostic tests were formulated and graded after the expert panel weighed desirable and undesirable consequences, certainty of estimates, feasibility, and acceptability.Results: The clinical presentation, histopathology, and exclusion of alternative diagnoses were summarized. On the basis of the available evidence, the expert committee made 1 strong recommendation for baseline serum calcium testing, 13 conditional recommendations, and 1 best practice statement. All evidence was very low quality.Conclusions: The panel used systematic reviews of the evidence to inform clinical recommendations in favor of or against various diagnostic tests in patients with suspected or known sarcoidosis. The evidence and recommendations should be revisited as new evidence becomes available.

Imbalance in B cell and T Follicular Helper Cell Subsets in Pulmonary Sarcoidosis.

Sarcoidosis is a systemic granulomatous disease that develops due to the Th1, Th17 and Treg lymphocytes disturbance. There is an assumption, that B cells and follicular T-helper (Tfh) cells may play an important role in this disorder, as well as in several other autoimmune diseases. The aim of this study was to determine CD19+ B cells subset distribution in the peripheral blood and to define disturbance in the circulating Tfh cells subsets in patients with sarcoidosis. The prospective comparative study was performed in 2016-2018, where peripheral blood B cell subsets and circulating Tfh cell subsets were analyzed in 37 patients with primarily diagnosed sarcoidosis and 35 healthy donors using multicolor flow cytometry. In the results of our study we found the altered distribution of peripheral B cell subsets with a predominance of "naïve" (IgD + CD27-) and activated B cell (Bm2 and Bm2') subsets and a decreased frequency of memory cell (IgD+ CD27+ and IgD- CD27+) in peripheral blood of sarcoidosis patients was demonstrated. Moreover, we found that in sarcoidosis patients there are increased levels of B cell subsets, which were previously shown to display regulatory capacities (CD24+++ CD38+++ and CD5 + CD27-). Next, a significantly higher proportion of CXCR5-expressing CD45RA - CCR7+ Th cells in patients with sarcoidosis in comparison to the healthy controls was revealed, that represents the expansion of this memory Th cell subset in the disease. This is the first study to demonstrate the association between the development of sarcoidosis and imbalance of circulating Tfh cells, especially CCR4- and CXCR3-expressing Tfh subsets. Finally, based on our data we can assume that B cells and Tfh2- and Tfh17-like cells - most effective cell type in supporting B-cell activity, particularly in antibody production - may be involved in the occurrence and development of sarcoidosis and in several other autoimmune conditions. Therefore, we can consider these results as a new evidence of the autoimmune mechanisms in the sarcoidosis development.

Pre-operative therapeutic plasma Exchange and intravenous immune globulin for the treatment of heparin induced thrombocytopenia in a lung transplant recipient.

Lung transplantation surgery often relies on the use of intraoperative extracorporeal membrane oxygenation (ECMO) and necessitates the need for high dose anticoagulation. Heparin induced thrombocytopenia complicates intraoperative anticoagulation management during lung transplant surgery requiring ECMO. Though other anticoagulants such as argatroban and bivalrudin are utilized for the treatment of Heparin Induced Thrombocytopenia (HIT), the lack of reversal agents makes it difficult to use these agents intraoperatively in cases with high bleeding risk. This is especially true in patients with end stage fibrotic lung disease with calcified mediastinal lymphadenopathy and pulmonary hypertension undergoing lung transplantation. Here we describe a case of HIT in a patient with Sarcoidosis listed for lung transplant who was treated with Therapeutic Plasma Exchange and Intravenous Immune globulin preoperatively and successfully underwent lung transplantation with the use of intraoperative venoarterial ECMO and heparin anticoagulation.

Plasma mitochondrial DNA is associated with extrapulmonary sarcoidosis.

Sarcoidosis is an unpredictable granulomatous disease in which African Americans disproportionately experience aggressive phenotypes. Mitochondrial DNA (mtDNA) released by cells in response to various stressors contributes to tissue remodelling and inflammation. While extracellular mtDNA has emerged as a biomarker in multiple diseases, its relevance to sarcoidosis remains unknown. We aimed to define an association between extracellular mtDNA and clinical features of sarcoidosis.Extracellular mtDNA concentrations were measured using quantitative PCR for the human MT-ATP6 gene in bronchoalveolar (BAL) and plasma samples from healthy controls and patients with sarcoidosis from The Yale Lung Repository; associations between MT-ATP6 concentrations and Scadding stage, extrapulmonary disease and demographics were sought. Results were validated in the Genomic Research in Alpha-1 Antitrypsin Deficiency and Sarcoidosis cohort.Relative to controls, MT-ATP6 concentrations in sarcoidosis subjects were robustly elevated in the BAL fluid and plasma, particularly in the plasma of patients with extrapulmonary disease. Relative to Caucasians, African Americans displayed excessive MT-ATP6 concentrations in the BAL fluid and plasma, for which the latter compartment correlated with significantly higher odds of extrapulmonary disease.Enrichments in extracellular mtDNA in sarcoidosis are associated with extrapulmonary disease and African American descent. Further study into the mechanistic basis of these clinical findings may lead to novel pathophysiologic and therapeutic insights.

Clinical Features and Outcomes of Patients with Sarcoidosis-associated Pulmonary Hypertension.

The presence of pulmonary hypertension (PH) significantly worsens outcomes in patients with advanced sarcoidosis, but its optimal management is unknown. We aimed to characterize a large sarcoidosis-associated pulmonary hypertension (SAPH) cohort to better understand patient characteristics, clinical outcomes, and management strategies including treatment with PH therapies. Patients at Duke University Medical Center with biopsy-proven sarcoidosis and SAPH confirmed by right heart catheterization (RHC) were identified from 1990-2010. Subjects were followed for up to 11 years and assessed for differences by treatment strategy for their SAPH, including those who were not treated with PH-specific therapies. Our primary outcomes of interest were change in 6-minute walk distance (6MWD) and change in N-terminal pro-brain natriuretic peptide (NT-proBNP) by after therapy. We included 95 patients (76% women, 86% African American) with SAPH. Overall, 70% of patients had stage IV pulmonary sarcoidosis, and 77% had functional class III/IV symptoms. Median NT-proBNP value was elevated (910 pg/mL), and right ventricular dysfunction was moderate/severe in 55% of patients. Median values for mean pulmonary artery pressure (49 mmHg) and pulmonary vascular resistance (8.5 Woods units) were consistent with severe pulmonary hypertension. The mortality rate over median 3-year follow-up was 32%. Those who experienced a clinical event and those who did not had similar overall echocardiographic findings, hemodynamics, 6MWD and NT-proBNP at baseline, and unadjusted analysis showed that only follow-up NT-proBNP was associated with all-cause hospitalization or mortality. A sign test to evaluate the difference between NT-Pro-BNP before and after PH therapy produced evidence that a significant difference existed between the median pre- and post-NT-Pro-BNP (-387.0 (IQR: -1373.0-109), p = 0.0495). Use of PH-specific therapy may be helpful in selected patients with SAPH and pre-capillary pulmonary vascular disease. Prospective trials are needed to characterize responses to PH-specific therapy in this subset of patients with SAPH.

Cathepsin S, a new serum biomarker of sarcoidosis discovered by transcriptome analysis of alveolar macrophages.

BACKGROUND: Development of reliable new biomarkers remains crucial to improve diagnosis and assessing disease activity in sarcoidosis. The objective of this study was to seek such markers from the gene expression signature of alveolar macrophages by transcriptome analysis. METHODS: Pooled RNA extracted from alveolar macrophages from patients with active sarcoidosis and control patients was subjected to transcriptome analysis using microarrays. Expressed gene intensity in sarcoidosis relative to that in control was calculated. We measured serum cathepsin S (CTSS) concentrations in 89 healthy volunteers, 107 patients with sarcoidosis, 26 with interstitial pneumonia, 150 with pneumoconiosis, and 76 with pulmonary mycobacteriosis by the enzyme-linked immunosorbent assay. RESULTS: Among 12 genes with ratios higher than that of a housekeeping gene, we selected CTSS for scrutinizing protein expression in serum because of the feasibility of the protein assay. CTSS concentrations were significantly increased in sarcoidosis compared with not only controls but also all the other lung diseases. Receiver operating characteristics curve for sarcoidosis and parenchymal lung diseases revealed an area under the curve of 0.800 (95% confidence interval, 0.751-0.850; p=1.4 x 10-18) with 70% sensitivity and 78% specificity at a CTSS concentration of 15.5 ng/ml. A significant trend was identified between CTSS concentrations and the number of affected organs. Serum CTSS concentrations varied in parallel with clinical courses both spontaneously and in response to corticosteroid therapy. Epithelioid cells in granulomas were positive for immunohistochemical staining with CTSS. CONCLUSIONS: CTSS has the potential to be a useful biomarker in sarcoidosis.

Proangiogenic and Profibrotic Markers in Pulmonary Sarcoidosis.

The aim of our study was to determine the blood levels of vascular endothelial growth factor (VEGF), transforming growth factor (TGF)-ß1, fibroblast growth factor (FGF)-2, and platelet-derived growth factor (PDGF)-AB in different stages of pulmonary sarcoidosis. There were 92 patients in sarcoidosis stages I + II, III, and IV enrolled into the study. All the patients underwent lung diffusing capacity and blood sampling. We found that VEGF levels differed significantly between the stage groups with the peak VEGF concentrations in stage III. TGF-ß1 levels were similar in stages I + II and III, and tended to be lower in stage IV. The analysis of the subgroups showed increased VEGF and FGF-2, and reduced TGF-ß1 concentration in stages I + II patients with relevantly reduced lung diffusing capacity or increased sarcoidosis activity compared to patients with normal lung diffusing capacity or inactive sarcoidosis. A tendency towards increased VEGF, PDGF-AB and TGF-ß1 levels was observed in the analogical subgroup analysis within the stage III. We conclude that proangiogenic VEGF, and profibrotic FGF-2 and PDGF-AB may contribute to the progression of sarcoidosis, whereas TGF-ß1, with its dual anti-inflammatory and profibrotic actions, may play a dichotomous protective or deleterious role. Reduced diffusing capacity and active sarcoidosis are associated with an unfavorable constellation of the markers studied, which predicts a progressive disease course.

Efficacy and safety of infliximab biosimilar Inflectra® in severe sarcoidosis.

BACKGROUND: Infliximab, a monoclonal antibody against tumor necrosis factor alpha (TNF-α) is effective third-line therapy in severe sarcoidosis. The originator product of Infliximab, Remicade®, is expensive, limiting universal access. Recently, a less expensive biosimilar of infliximab, Inflectra®, has become available, but the efficacy and tolerability has not been studied in sarcoidosis. METHODS: In this retrospective cohort study, 29 patients treated with the infliximab biosimilar Inflectra®, were analysed. Patients received Inflectra® intravenously monthly at a dose of 5 mg/kg. We measured trough levels before every infusion. Before and after 6 months of induction therapy pulmonary function and disease activity were evaluated using Standardised Uptake Value (SUV) of the 18F-fluorodeoxyglucose by positron emission tomography (18F-FDG PET), soluble interleukin-2 receptor (sIL-2R), angiotensin converting enzyme (ACE) and health-related quality of life (HRQOL). RESULTS: In patients with pulmonary sarcoidosis as main treatment indication (n = 15) the predicted FVC improved with 8.1%, p < 0.05. Furthermore, in the whole group HRQoL improved significantly (p < 0.001), whereas SUVmax and sIL-2R significantly reduced (p < 0.001 and p = 0.001 respectively). Hospitalisation due to infections occurred in four patients. None of the patients discontinued Inflectra® due to side-effects. Furthermore, all patients had detectable trough levels indicating development of neutralizing antibodies. CONCLUSION: Infliximab biosimilar Inflectra® seems effective in the treatment of refractory sarcoidosis with a comparable safety profile to the reference product Remicade®. Inflectra® can be considered as an alternative and less expensive option for patients with refractory sarcoidosis.

Clinical significance of the determination of surfactant proteins A and D in assessing the activity of lung sarcoidosis.

AIM: To study the clinical significance of SP-A, SP-D in assessing the activity of idiopathic pulmonary fibrosis and sarcoidosis. We examined 81 patients with morphologically confirmed diagnoses of idiopathic pulmonary fibrosis (ILF) and sarcoidosis, a control group of 20 healthy individuals. The MSCT of the thoracic organs of the chest was performed, the diffusivity of the lungs was examined, oxygen saturation was determined. In the serum, the surfactant proteins SP-A and SP-D were determined by the enzyme-linked immunosorbent assay. RESULTS: A significant increase in SP-A and SP-D (p<0.05) was observed in patients compared with patients in the control group, a direct correlation was found with signs of activity: SP-A with alveolitis (p<0.05), SP- D with progressive fibrosis (p<0.05), inverse correlation of surfactant proteins with respiratory function indices (p<0.05). CONCLUSION: Serological parameters of SP-A and SP-D reflect the activity of alveolitis and the progression of pulmonary fibrosis in patients with ILF and sarcoidosis.

Vitamin D, Cathelicidin, Prolactin, Autoantibodies, and Cytokines in Different Forms of Pulmonary Tuberculosis versus Sarcoidosis.

BACKGROUND: Vitamin D insufficiency is associated with autoimmune and chronic inflammatory diseases such as tuberculosis and sarcoidosis. OBJECTIVES: To evaluate the vitamin D-dependent mechanisms of immunity and autoimmunity in different forms of pulmonary tuberculosis and sarcoidosis. METHODS: We measured the serum levels of 25(OH)D and 1,25(OH)2D, individual autoimmune profiles, plasma concentrations of cathelicidin, several hormones, and production of nine cytokines in patients with short- and long-duration tuberculosis and sarcoidosis. RESULTS: The level of 25(OH)D was significantly decreased in all patients. Concentration of 1,25(OH)2D was elevated only in sarcoidosis, prolactin content was augmented only in tuberculosis. We saw no expected increase of cathelicidin levels in tuberculosis and sarcoidosis. The individual mean immune reactivity levels of autoantibodies to 24 antigens were significantly lower in tuberculosis and sarcoidosis patients compared to healthy controls. Pronounced deviations from individual mean immune reactivity levels were found for several autoantigens in all patients. The induced production of interferon gamma-γ, interleukin (IL) 2, 17, and 8 by peripheral blood mononuclear cells was significantly increased in patients of both tuberculosis groups, but spontaneous production of tumor necrosis factor-α, IL-2, and IL-6 was lower in the tuberculosis patients than in healthy controls. We registered marked differences in the groups of tuberculosis patients. CONCLUSIONS: We demonstrated the role of vitamin D deficiency in poor cathelicidin response in  tuberculosis and sarcoidosis. Both diseases are accompanied by significant changes in the autoimmune profile, probably related to the status of vitamin D and cytokine regulation.

Immunotherapy-induced sarcoidosis in patients with melanoma treated with PD-1 checkpoint inhibitors: Case series and immunophenotypic analysis.

AIM: Sarcoidosis is a multisystem granulomatous disease. This condition has a documented association with the diagnosis of melanoma and can be induced in melanoma patients receiving anti-neoplastic therapy. We evaluated a case series of melanoma patients who developed immunotherapy-induced sarcoidosis. METHODS: Three patients with melanoma (n = 1 resected Stage III, n = 2 metastatic) treated with anti-programmed cell death (PD)-1 antibody therapy at two institutions developed biopsy-proven sarcoidosis. We used mass cytometry to determine expression of the relevant chemokine receptors (CR) by peripheral blood mononuclear cells for two of the three patients who developed sarcoidosis and 13 melanoma patients who did not. Blood samples were collected before receiving PD-1 checkpoint inhibitor therapy. RESULTS: Immunophenotypic analysis demonstrated abnormally high numbers of circulating Th17.1 (CCR6+ CCR4- CXCR3+ CCR10- ) cells prior to commencing PD-1 checkpoint inhibitor therapy in five of 15 melanoma patients, including both the patients who developed sarcoidosis during the course of therapy. CONCLUSION: Our findings support prior literature implicating Th17.1 cells in the pathogenesis of sarcoidosis. However, we demonstrate these findings in patients with melanoma prior to administration of checkpoint therapy and before the onset of clinically symptomatic sarcoidosis. The identification of elevated Th17.1 cells in melanoma patients who have not developed sarcoidosis may reflect the established association between melanoma and sarcoidosis. With some patients receiving these agents over a prolonged period, the clinical course of immunotherapy-induced sarcoidosis is uncertain.