It's time to evolve from Scadding: phenotyping sarcoidosis

Circulating Mitochondrial DNA Is Associated With High Levels of Fatigue in Two Independent Sarcoidosis Cohorts

BACKGROUND

Patients with sarcoidosis who develop severe clinical phenotypes of pulmonary fibrosis or multiorgan disease experience debilitating symptoms, with fatigue being a common chief complaint. Studies that have investigated this patient-related outcome measure (PROM) have used the Fatigue Assessment Scale (FAS), a self-reported questionnaire that reflects mental and physical domains. Despite extensive work, its cause is unknown and treatment options remain limited. Previously, we showed that the plasma of patients with sarcoidosis with extrapulmonary disease endorsing fatigue was enriched for mitochondrial DNA (mtDNA), a ligand for the innate immune receptor toll-like receptor 9 (TLR9). Through our cross-disciplinary platform, we investigated a relationship between sarcoidosis-induced fatigue and circulating mtDNA.

RESEARCH QUESTION

Is there a psychobiologic mechanism that connects sarcoidosis-induced fatigue and mtDNA-mediated TLR9 activation?

STUDY DESIGN AND METHODS

Using a local cohort of patients at Yale (discovery cohort) and the National Institutes of Health-sponsored Genomic Research in Alpha-1 Antitrypsin Deficiency and Sarcoidosis study (validation cohort), we scored the FAS and quantified in the plasma, mtDNA concentrations, TLR9 activation, and cytokine levels.

RESULTS

Although FAS scores were independent of corticosteroid use and Scadding stage, we observed a robust association between FAS scores, which included mental and physical domains, and multiorgan sarcoidosis. Subsequently, we identified a significant correlation between plasma mtDNA concentrations and all domains of fatigue. Additionally, we found that TLR9 activation is associated with all aspects of the FAS and partially mediates this PROM through mtDNA. Last, we found that TLR9-associated soluble mediators in the plasma are independent of all facets of fatigue.

INTERPRETATION

Through our cross-disciplinary translational platform, we identified a previously unrecognized psychobiologic connection between sarcoidosis-induced fatigue and circulating mtDNA concentrations. Mechanistic work that investigates the contribution of mtDNA-mediated innate immune activation in this PROM and clinical studies with prospective cohorts has the potential to catalyze novel therapeutic strategies for this patient population and those with similar conditions.

High-Resolution CT Scan Fibrotic Patterns in Stage IV Pulmonary Sarcoidosis: Impact on Pulmonary Function and Survival

BACKGROUND

Different patterns of fibrosis on high-resolution CT scans (HRCT) have been associated with reduced survival in some interstitial lung diseases. Nothing is known about HRCT scan patterns and survival in sarcoidosis.

RESEARCH QUESTION

Will a detailed description of the extent and pattern of HRCT scan fibrosis in patients with stage IV pulmonary sarcoidosis impact pulmonary function and survival?

STUDY DESIGN AND METHODS

Two hundred forty patients with stage IV sarcoidosis at two large tertiary institutions were studied. The earliest HRCT scan with fibrosis was reviewed for extent of fibrosis (< 10%, 10%-20%, and > 20%) and presence of bronchiectasis, upper lobe fibrocystic changes, basal subpleural honeycombing, ground-glass opacities (GGOs), large bullae, and mycetomas. Presence of sarcoidosis-associated pulmonary hypertension (SAPH) and pulmonary function testing performed within 1 year of HRCT were recorded. Patients were followed up until last clinic visit, death, or lung transplantation.

RESULTS

The mean age was 58.4 years. Seventy-four percent were Black, 63% were female, and mean follow-up was 7.4 years. Death or LT occurred in 53 patients (22%). Thirty-one percent had > 20% fibrosis, 25% had 10%-20% fibrosis, and 44% had < 10% fibrosis. The most common HRCT abnormalities were bronchiectasis (76%), upper lobe fibrocystic changes (36%), and GGOs (28%). Twelve percent had basal subpleural honeycombing, and 32% had SAPH. Patients with > 20% fibrosis had more severe pulmonary impairment, were more likely to have SAPH (53%), and had worse survival (44% mortality; P < .001). Upper lobe fibrocystic changes, basal subpleural honeycombing, and large bullae were associated with worse pulmonary function and worse survival. Patients with basal subpleural honeycombing had the worst pulmonary function and survival (55% mortality; P < .001). GGOs were associated with worse pulmonary function but not worse survival, and mycetomas were associated with worse survival but not worse pulmonary function. A Cox proportional hazards model indicated that basal subpleural honeycombing (hazard ratio, 7.95), diffusion capacity for carbon monoxide < 40% (HR, 5.67) and White race (hazard ratio, 2.61) were independent predictors of reduced survival.

INTERPRETATION

HRCT scan features of fibrotic pulmonary sarcoidosis had an impact on pulmonary function and survival. Presence of >20% fibrosis and basal subpleural honeycombing are predictive of worse pulmonary function and worse survival in patients with stage IV pulmonary sarcoidosis.

Phenotypes and Serum Biomarkers in Sarcoidosis

Sarcoidosis is a multisystem disease, which is diagnosed on a compatible clinical presentation, non-necrotizing granulomatous inflammation in one or more tissue samples, and exclusion of alternative causes of granulomatous disease. Considering its heterogeneity, numerous aspects of the disease remain to be elucidated. In this context, the identification and integration of biomarkers may hold significance in clinical practice, aiding in appropriate selection of patients for targeted clinical trials. This work aims to discuss and analyze how validated biomarkers are currently integrated in disease category definitions. Future studies are mandatory to unravel the diverse contributions of genetics, socioeconomic status, environmental exposures, and other sociodemographic variables to disease severity and phenotypic presentation. Furthermore, the implementation of transcriptomics, multidisciplinary approaches, and consideration of patients' perspectives, reporting innovative insights, could be pivotal for a better understanding of disease pathogenesis and the optimization of clinical assistance.

High-Definition Videobronchoscopy for the Diagnosis of Airway Involvement in Sarcoidosis: The Enhance Sarcoidosis Multicenter Study

BACKGROUND

The ability of high-definition (HD) videobronchoscopy to detect airway involvement in sarcoidosis has not been evaluated previously.

RESEARCH QUESTION

What is the role of HD videobronchoscopy in the identification of sarcoidosis-associated airway abnormalities (AAs)? What are the patterns of AAs more commonly observed and more frequently associated with the detection of granulomas in endobronchial biopsy (EBB)?

STUDY DESIGN AND METHODS

In this prospective international multicenter cohort study, consecutive patients with suspected sarcoidosis underwent airway inspection with an HD videobronchoscope and EBB using a standardized workflow. AAs were classified according to six patterns defined a priori: nodularity, cobblestoning, thickening, plaque, increased vascularity, and miscellaneous. We assessed diagnostic yield of EBB, prevalence of AAs, and interobserver agreement for different patterns of AAs.

RESULTS

AAs were identified in 64 of 134 patients with sarcoidosis (47.8%), with nodularity (n = 23 [17.2%]), plaque (n = 19 [14.2%]), and increased vascularity (n = 19 [14.2%]) being the most prevalent. The diagnostic yield of EBB was 36.6%. AAs were significantly more prevalent in patients with than in those without nonnecrotizing granulomas on EBB (67.4% vs 36.5%; P = .001). Likewise, parenchymal disease on CT scan imaging was significantly more common in patients with than in those without nonnecrotizing granulomas on EBB (79.6% vs 54.1%; P = .003). On a per-lesion analysis, nonnecrotizing granulomas were seen especially in EBB samples obtained from areas of cobblestoning (9/10 [90%]) and nodularity (17/29 [58.6%]). The overall diagnostic yield of random EBB was low (31/134 [23.1%]). The interobserver agreement for the different patterns of AA was fair (Fleiss κ = 0.34).

INTERPRETATION

In a population with a large prevalence of White Europeans, HD videobronchoscopy detected AAs in approximately one-half of patients with sarcoidosis. The diagnostic yield of EBB was higher in patients with parenchymal involvement on CT scan imaging and in those with AAs, especially if manifesting as cobblestoning and nodularity.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT4743596; URL: www.

CLINICALTRIALS

gov.

Current Applications of Artificial Intelligence in Sarcoidosis

PURPOSE

Sarcoidosis is a complex disease which can affect nearly every organ system with manifestations ranging from asymptomatic imaging findings to sudden cardiac death. As such, diagnosis and prognostication are topics of continued investigation. Recent technological advancements have introduced multiple modalities of artificial intelligence (AI) to the study of sarcoidosis. Machine learning, deep learning, and radiomics have predominantly been used to study sarcoidosis.

METHODS

Articles were collected by searching online databases using keywords such as sarcoid, machine learning, artificial intelligence, radiomics, and deep learning. Article titles and abstracts were reviewed for relevance by a single reviewer. Articles written in languages other than English were excluded.

CONCLUSIONS

Machine learning may be used to help diagnose pulmonary sarcoidosis and prognosticate in cardiac sarcoidosis. Deep learning is most comprehensively studied for diagnosis of pulmonary sarcoidosis and has less frequently been applied to prognostication in cardiac sarcoidosis. Radiomics has primarily been used to differentiate sarcoidosis from malignancy. To date, the use of AI in sarcoidosis is limited by the rarity of this disease, leading to small, suboptimal training sets. Nevertheless, there are applications of AI that have been used to study other systemic diseases, which may be adapted for use in sarcoidosis. These applications include discovery of new disease phenotypes, discovery of biomarkers of disease onset and activity, and treatment optimization.

Pulmonary Sarcoidosis and Immune Dysregulation: A Pilot Study on Possible Correlation

BACKGROUND

Sarcoidosis is a systemic inflammatory disease characterized by an altered inflammatory response.

OBJECTIVE

The aim of this study was to evaluate whether immune system alterations detected by lymphocyte typing in peripheral blood correlate with the severity of sarcoidosis, calculated according to two separate severity scores proposed by Wasfi in 2006 and Hamzeh in 2010.

MATERIALS AND METHODS

Eighty-one patients were recruited, and clinical data and laboratory tests at the time of diagnosis were obtained in order to assess the severity index score and investigate any statistically significant correlation with the cytofluorimetry data.

RESULTS

Our data demonstrated that none of the two scores show an association with the level of total lymphocytes or lymphocyte subclasses.

LIMITATIONS

First of all, the sample taken into consideration is small. The assessment was performed only at disease onset and not during the disease. Furthermore, the severity scores do not take into account disease activity (measured by PET/CT or gallium scintigraphy).

CONCLUSIONS

Lymphocyte subpopulation values at the time of diagnosis do not appear to correlate with disease severity at onset.

Correlation of the High-Resolution Computed Tomography Patterns of Intrathoracic Sarcoidosis with Serum Levels of SAA, CA 15.3, SP-D, and Other Biomarkers of Interstitial Lung Disease

Studies on the serum biomarkers of granulomatous inflammation and pulmonary interstitial disease in intrathoracic sarcoidosis have shown conflicting results. We postulated that differences in the concentrations of serum biomarkers can be explained by the heterogenous patterns of sarcoidosis seen on thoracic HRCT. Serum biomarker levels in 79 consecutive patients, newly diagnosed with intrathoracic sarcoidosis, were compared to our control group of 56 healthy blood donors. An analysis was performed with respect to HRCT characteristics (the presence of lymph node enlargement, perilymphatic or peribronchovascular infiltrates, ground-glass lesions, or fibrosis), CXR, and disease extent. Serum levels of CXCL9, CXCL10, CTO, and CCL18 were statistically significantly increased in all patients compared to controls. Serum levels of CA15.3 were statistically significantly increased in all patients with parenchymal involvement. SAA was increased in patients with ground-glass lesions while SP-D levels were statistically significantly increased in patients with lung fibrosis. Only SP-D and CA15.3 showed a significant correlation to interstitial disease extent. In conclusion, we found that sarcoidosis patients with different HRCT patterns of intrathoracic sarcoidosis have underlying biochemical differences in their serum biomarkers transcending Scadding stages. The stratification of patients based on both radiologic and biochemical characteristics could enable more homogenous patient selection for further prognostic studies.

Molecular Mechanism in the Development of Pulmonary Fibrosis in Patients with Sarcoidosis

Sarcoidosis is a multisystemic disease of unknown etiology characterized by the formation of granulomas in various organs, especially lung and mediastinal hilar lymph nodes. The clinical course and manifestations are unpredictable: spontaneous remission can occur in approximately two thirds of patients; up to 20% of patients have chronic course of the lung disease (called advanced pulmonary sarcoidosis, APS) resulting in progressive loss of lung function, sometimes life-threatening that can lead to respiratory failure and death. The immunopathology mechanism leading from granuloma formation to the fibrosis in APS still remains elusive. Recent studies have provided new insights into the genetic factors and immune components involved in the clinical manifestation of the disease. In this review we aim to summarize the clinical-prognostic characteristics and molecular pathways which are believed to be associated with the development of APS.

From Karl Wurm and Guy Scadding's staging to 18F-FDG PET/CT scan phenotyping and far beyond: perspective in the evading history of phenotyping in sarcoidosis

Sarcoidosis is an inflammatory granulomatous disease of unknown etiology involving any organ or tissue along with any combination of active sites, even the most silent ones clinically. The unpredictable nature of the sites involved in sarcoidosis dictates the highly variable natural history of the disease and the necessity to cluster cases at diagnosis based on clinical and/or imaging common characteristics in an attempt to classify patients based on their more homogeneous phenotypes, possibly with similar clinical behavior, prognosis, outcome, and therefore with therapeutic requirements. In the course of the disease's history, this attempt relates to the availability of a means of detection of the sites involved, from the Karl Wurm and Guy Scadding's chest x-ray staging through the ACCESS, the WASOG Sarcoidosis Organ Assessment Instruments, and the GenPhenReSa study to the 18F-FDG PET/CT scan phenotyping and far beyond to new technologies and/or the current "omics." The hybrid molecular imaging of the 18F-FDG PET/CT scan, by unveiling the glucose metabolism of inflammatory cells, can identify high sensitivity inflammatory active granulomas, the hallmark of sarcoidosis-even in clinically and physiologically silent sites-and, as recently shown, is successful in identifying an unexpected ordered stratification into four phenotypes: (I) hilar-mediastinal nodal, (II) lungs and hilar-mediastinal nodal, (III) an extended nodal supraclavicular, thoracic, abdominal, inguinal, and (IV) all the above in addition to systemic organs and tissues, which is therefore the ideal phenotyping instrument. During the "omics era," studies could provide significant, distinct, and exclusive insights into sarcoidosis phenotypes linking clinical, laboratory, imaging, and histologic characteristics with molecular signatures. In this context, the personalization of treatment for sarcoidosis patients might have reached its goal.

Treat to target and tight control: Could be a new approach in the treatment of sarcoidosis?

Sarcoidosis is a chronic granulomatous disease with multisystemic involvement. Although it is accepted as a benign disease, it can sometimes cause life-threatening organ (heart, brain) involvement that determines the prognosis of the disease. There are conflicting opinions about the treatment of the disease. In the generally accepted treatment approach the "step-by-step" model has gained weight. According to this approach, corticosteroids (CS) drugs alone are preferred in the first step in patients who require treatment. In the second step, immunosuppressive drugs (IS) are used in patients who do not respond to CS and/or have contraindications to CS use, and biologics (TNF-alpha inhibitors) are used in the third step. This treatment approach may be valid in cases with mild sarcoidosis. However, although sarcoidosis is considered a benign and self-limiting disease in some major organ involvement, the "step-by-step" approach may be a treatment option that puts the patient's life in danger. In such selected patients, much more rigorous, early and combined treatment approaches that definitely include CS, IS or biologic drugs may be required. In selected sarcoidosis patients with high risk, early diagnosis, "treat-to-target" (T2T) and "tight control" follow-up of patients seems to be a rational approach. This article reviews the "step-down" treatment regimens in light of recent literature data and hypothesizes that the T2T model may be a probable new treatment approach in patients with sarcoidosis.

Clinical Utility of 18F-FDG PET/CT in the Work-up of Children with Uveitis

PURPOSE

To evaluate ¹⁸F-fluorodeoxyglucose Positron Emission Tomography/ultra low dose Computed Tomography (¹⁸F-FDG PET/ ULD CT) in the work-up of pediatric uveitis.

METHODS

Retrospective study of 12 children followed for uveitis who underwent whole body ¹⁸F-FDG PET/ULD CT between 2011 and 2019.

RESULTS

The average age of the patients was 11 years. A total of 100% of patients presented with bilateral uveitis, 50% had panuveitis and 92% had various choroidal involvement. Relevant information for diagnosis was provided in four patients. 5/12 had an abnormal 18F-FDG uptake. Of these, three patients had pathognomonic images of active granulomatous diseases. Three patients underwent PET CT-guided biopsies of which two were positive for sarcoidosis.

CONCLUSION

¹⁸F-FDG PET/CT provided important information for final diagnosis in approximately 30% (4/12) of pediatric patients with bilateral uveitis. Whole body FDG PET/ULD CT can contribute to the final diagnosis thanks to pathognomonic image of active granulomatous disease and/or by indicating metabolically active site of biopsy that would not be visualized in thorax CT.

Sarcoidosis: Updates on therapeutic drug trials and novel treatment approaches

Sarcoidosis is a systemic granulomatous inflammatory disease of unknown etiology. It affects the lungs in over 90% of patients yet extra-pulmonary and multi-organ involvement is common. Spontaneous remission of disease occurs commonly, nonetheless, over 50% of patients will require treatment and up to 30% of patients will develop a chronic progressive non-remitting disease with marked pulmonary fibrosis leading to significant morbidity and death. Guidelines outlining an immunosuppressive treatment approach to sarcoidosis were recently published, however, the strength of evidence behind many of the guideline recommended drugs is weak. None of the drugs currently used for the treatment of sarcoidosis have been rigorously studied and prescription of these drugs is often based on off-label” indications informed by experience with other diseases. Indeed, only two medications [prednisone and repository corticotropin (RCI) injection] currently used in the treatment of sarcoidosis are approved by the United States Food and Drug Administration. This situation results in significant reimbursement challenges especially for the more advanced (and often more effective) drugs that are favored for severe and refractory forms of disease causing an over-reliance on corticosteroids known to be associated with significant dose and duration dependent toxicities. This past decade has seen a renewed interest in developing new drugs and exploring novel therapeutic pathways for the treatment of sarcoidosis. Several of these trials are active randomized controlled trials (RCTs) designed to recruit relatively large numbers of patients with a goal to determine the safety, efficacy, and tolerability of these new molecules and therapeutic approaches. While it is an exciting time, it is also necessary to exercise caution. Resources including research dollars and most importantly, patient populations available for trials are limited and thus necessitate that several of the challenges facing drug trials and drug development in sarcoidosis are addressed. This will ensure that currently available resources are judiciously utilized. Our paper reviews the ongoing and anticipated drug trials in sarcoidosis and addresses the challenges facing these and future trials. We also review several recently completed trials and draw lessons that should be applied in future.

Clinical, imaging and functional determinants of sarcoidosis phenotypes in a Greek population

Background

The aim of the present study was the application of the latest phenotype recommendations in Greek patients, in order to identify specific clinical, imaging and spirometric characteristics, at initial diagnosis of sarcoidosis, related to disease phenotypes.

Methods

Our cohort included 147 patients coming from Northern Greece, recruited from the Outpatient Sarcoidosis Clinic, of Aristotle University of Thessaloniki. The observation period was 5 years. The Scadding staging system and the World Association of Sarcoidosis and other Granulomatous Disorders (WASOG) Clinical Outcome Status instrument were used. Phenotypes were defined by the latest DELPHI consensus recommendations.

Results

The following clinical phenotypes were identified: asymptomatic 59%, acute 14.3%, chronic 12.9% and advanced 33.3%. The observed phenotypes were not related to Scadding stages. Lung function decline was in line with phenotype severity. The presence of fibrosis to any extent upon diagnosis differed among phenotypes (asymptomatic 13.8%, acute 38.1%, chronic 57.9%, advanced 61.2%, P<0.001) and was common for relapsing patients (P<0.001). In spontaneously remitting patients, fibrosis upon diagnosis was found less often than in non-remitting patients (P<0.001). Renal involvement was more frequently found in the advanced phenotype (P=0.032). Skin involvement was more common for patients with acute onset (P<0.001) and spontaneous remission (P=0.012). Ocular involvement was mainly found in relapsing patients (P<0.001).

Conclusions

In our cohort, sarcoidosis clinical phenotypes have certain clinical, imaging and functional characteristics, at initial diagnosis of the disease, which could be assessed in everyday practice.

Emerging insights in sarcoidosis: moving forward through reverse translational research

Sarcoidosis is a chronic granulomatous disease of unknown etiology that primarily affects the lungs. The development of stage IV or fibrotic lung disease accounts for a significant proportion of the morbidity and mortality attributable to sarcoidosis. Further investigation into the active mechanisms of disease pathogenesis and fibrogenesis might illuminate fundamental mediators of injury and repair while providing new opportunities for clinical intervention. However, progress in sarcoidosis research has been hampered by the heterogeneity of clinical phenotypes and the lack of a consensus modeling system. Recently, reverse translational research, wherein observations made at the patient level catalyze hypothesis-driven research at the laboratory bench, has generated new discoveries regarding the immunopathogenic mechanisms of pulmonary granuloma formation, fibrogenesis, and disease model development. The purpose of this review is to highlight the promise and possibility of these novel investigative efforts.

Clinical characteristics of sarcoidosis patients in Belgium

BACKGROUND

Sarcoidosis is a non-caseating granulomatous disease, mostly affecting previously healthy persons in their fourth and fifth decade. In Belgium, there is a paucity of epidemiological data concerning sarcoidosis and it is unknown to what respect national data on sarcoidosis relates to the global epidemiology of the disease.

OBJECTIVES

In this cohort study we describe the patient population in an academic center of reference, serving both as a regional care center and a center for a tertiary referral.

METHODS

We collected epidemiological data among 234 consecutive patients consulting the outpatient sarcoidosis clinic during a two-year time period. We manually explored the electronic patient file for data retrieval.

RESULTS

Out of the 234 patients, 140 are male (60%) and 94 are female (40%) patients. Forced vital capacity showed a median decline of 2% during follow-up, whereas median diffusion capacity increased with 4% over the same period of time. Within our study cohort, we observed a preponderance in employment as construction workers (14%), the chemical industry (6%) and in the metal processing industry (6%).

CONCLUSION

The current study reports on epidemiological findings among the largest cohort of sarcoidosis patients in Belgium published to date.

Graphical abstract [Figure: see text].

Transcriptomics of bronchoalveolar lavage cells identifies new molecular endotypes of sarcoidosis

BACKGROUND

Sarcoidosis is a multisystem granulomatous disease of unknown origin with a variable and often unpredictable course and pattern of organ involvement. In this study we sought to identify specific bronchoalveolar lavage (BAL) cell gene expression patterns indicative of distinct disease phenotypic traits.

METHODS

RNA sequencing by Ion Torrent Proton was performed on BAL cells obtained from 215 well-characterised patients with pulmonary sarcoidosis enrolled in the multicentre Genomic Research in Alpha-1 Antitrypsin Deficiency and Sarcoidosis (GRADS) study. Weighted gene co-expression network analysis and nonparametric statistics were used to analyse genome-wide BAL transcriptome. Validation of results was performed using a microarray expression dataset of an independent sarcoidosis cohort (Freiburg, Germany; n=50).

RESULTS

Our supervised analysis found associations between distinct transcriptional programmes and major pulmonary phenotypic manifestations of sarcoidosis including T-helper type 1 (Th1) and Th17 pathways associated with hilar lymphadenopathy, transforming growth factor-β1 (TGFB1) and mechanistic target of rapamycin (MTOR) signalling with parenchymal involvement, and interleukin (IL)-7 and IL-2 with airway involvement. Our unsupervised analysis revealed gene modules that uncovered four potential sarcoidosis endotypes including hilar lymphadenopathy with increased acute T-cell immune response; extraocular organ involvement with PI3K activation pathways; chronic and multiorgan disease with increased immune response pathways; and multiorgan involvement, with increased IL-1 and IL-18 immune and inflammatory responses. We validated the occurrence of these endotypes using gene expression, pulmonary function tests and cell differentials from Freiburg.

CONCLUSION

Taken together, our results identify BAL gene expression programmes that characterise major pulmonary sarcoidosis phenotypes and suggest the presence of distinct disease molecular endotypes.

Genomic biomarkers in chronic beryllium disease and sarcoidosis

Background Previous gene expression studies have identified genes IFNγ, TNFα, RNase 3, CXCL9, and CD55 as potential biomarkers for sarcoidosis and/or chronic beryllium disease (CBD). We hypothesized that differential expression of these genes could function as diagnostic biomarkers for sarcoidosis and CBD, and prognostic biomarkers for sarcoidosis. Study Design/Methods We performed RT-qPCR on whole blood samples from CBD (n = 132), beryllium sensitized (BeS) (n = 109), and sarcoidosis (n = 99) cases and non-diseased controls (n = 97) to determine differential expression of target genes. We then performed logistic regression modeling and generated ROC curves to determine which genes could most accurately differentiate: 1) CBD versus sarcoidosis 2) CBD versus BeS 3) sarcoidosis versus controls 4) non-progressive versus progressive sarcoidosis. Results CD55 and TNFα were significantly upregulated, while CXCL9 was significantly downregulated in CBD compared to sarcoidosis (p < 0.05). The ROC curve from the logistic regression model demonstrated high discriminatory ability of the combination of CD55, TNFα, and CXCL9 to distinguish between CBD and sarcoidosis with an AUC of 0.98. CD55 and TNFα were significantly downregulated in sarcoidosis compared to controls (p < 0.05). The ROC curve from the model showed a reasonable discriminatory ability of CD55 and TNFα to distinguish between sarcoidosis and controls with an AUC of 0.86. There was no combination of genes that could accurately differentiate between CBD and BeS or sarcoidosis phenotypes. Interpretation CD55, TNFα and CXCL9 expression levels can accurately differentiate between CBD and sarcoidosis, while CD55 and TNFα expression levels can accurately differentiate sarcoidosis and controls.

Key Players and Biomarkers of the Adaptive Immune System in the Pathogenesis of Sarcoidosis

Sarcoidosis is a systemic inflammatory disease characterized by development of granulomas in the affected organs. Sarcoidosis is often a diagnosis of exclusion, and traditionally used tests for sarcoidosis demonstrate low sensitivity and specificity. We propose that accuracy of diagnosis can be improved if biomarkers of altered lymphocyte populations and levels of signaling molecules involved in disease pathogenesis are measured for patterns suggestive of sarcoidosis. These distinctive biomarkers can also be used to determine disease progression, predict prognosis, and make treatment decisions. Many subsets of T lymphocytes, including CD8⁺ T-cells and regulatory T-cells, have been shown to be dysfunctional in sarcoidosis, and the predominant CD4⁺ T helper cell subset in granulomas appears to be a strong indicator of disease phenotype and outcome. Studies of altered B cell populations, B cell signaling molecules, and immune complexes in sarcoidosis patients reveal promising biomarkers as well as possible explanations of disease etiology. Furthermore, examined biomarkers raise questions about new treatment methods and sarcoidosis antigens.

Nonlife-Threatening Sarcoidosis

Sarcoidosis is a systemic granulomatous disease of unknown etiology. The outcome is quite variable and is mainly related to persistent inflammatory processes and the development of fibrosis. Many prognostic factors have been described, but the disease evolution is not yet entirely known. The nonthreatening course is characterized by spontaneous involution or stability after treatment withdrawal. Löfgren's syndrome is a subset within the spectrum of sarcoidosis phenotypes, composed of acute onset of fever, bilateral hilar lymphadenopathy, erythema nodosum and/or bilateral ankle periarticular inflammation/arthritis, specifically characterized by a self-limiting disease course. In contrast, advanced fibrotic sarcoidosis with pulmonary hypertension phenotype is correlated with a poor prognosis. Further studies are necessary to detail phenotypes to better understand the mechanisms of the disease and plan future clinical therapeutic studies.

Systemic phenotype of sarcoidosis associated with radiological stages. Analysis of 1230 patients

BACKGROUND

To analyze the association between Scadding radiological stages of sarcoidosis at diagnosis and the disease phenotype (epidemiology, clinical presentation and extrathoracic involvement) in one of the largest cohorts of patients with sarcoidosis reported from southern Europe.

METHODS

The SARCOGEAS-Study Group includes a multicenter database of consecutive patients diagnosed with sarcoidosis according to the WASOG 1999 criteria. Extrathoracic disease at diagnosis was defined according to the 2014 instrument and the clusters proposed by Schupp et al. RESULTS: We analyzed 1230 patients (712 female, mean age 47 yrs.) who showed the following Scadding radiologic stages at diagnosis: stage 0 (n = 98), stage I (n = 395), stage II (n = 500), stage III (n = 195) and stage IV (n = 42). Women were overrepresented in patients presenting with extrathoracic/extrapulmonary disease, while the diagnosis was made at younger ages in patients presenting with BHL, and at older ages in those presenting with pulmonary fibrosis (q values <0.05). Multivariable adjusted analysis showed that patients presenting with pulmonary involvement (especially those with stages II and III) had a lower frequency of concomitant systemic involvement in some specific extrathoracic clusters (cutaneous-adenopathic/musculoskeletal, ENT and neuro-ocular/OCCC) but a higher frequency for others (hepatosplenic), in comparison with patients with extrapulmonary involvement (stages 0 and I). The presence of either BHL or fibrotic lesions did not influence the systemic phenotype of patients with pulmonary involvement.

CONCLUSIONS

The key determinant associated with a differentiated systemic phenotype of sarcoidosis at diagnosis was interstitial pulmonary involvement rather than the individual Scadding radiological stage.

Lung transplantation for pulmonary sarcoidosis

Although relatively few patients with pulmonary sarcoidosis develop advanced disease that progresses to respiratory insufficiency despite receiving best practice pharmacologic interventions, lung transplantation may be the only therapeutic option for such patients to both prolong survival and provide improved quality of life. Lung transplant can be successfully performed for patients with end-stage pulmonary sarcoidosis, and post-transplant survival is similar to that for other transplant indications such as idiopathic pulmonary fibrosis. However, appropriate timing of referral, comprehensive assessment of potential candidates for lung transplant, placement of patients on the lung transplant waiting list when within the transplant window as appropriate, choosing the best procedure (bilateral versus single lung transplant), and optimal peri-operative and post-transplant management are key to successful lung transplant outcomes for patients with sarcoidosis.