Sarcoidosis and autoimmunity

[Sequential autoimmunity? The rare case of MDA5 dermatomyositis and sarcoidosis]

BACKGROUND

Anti-MDA5 positive dermatomyositis is a rare subtype of idiopathic inflammatory myopathies often accompanied by rapidly progressive interstitial lung disease and severe cutaneous ulcerations. It is associated with a high mortality. The simultaneous occurrence of sarcoidosis with multisystemic involvement of myositis has only been described very rarely in the literature to date.

CASE REPORT

We report the case of a 39-year-old man with a 3-year history of anti-MDA‑5 positive dermatomyositis who developed a worsening of dyspnea and hypercalcemia with acute kidney injury and a marked deterioration in his general condition after successive reductions in immunosuppressive therapy. A bronchoscopy and lymph node biopsy ultimately confirmed the diagnosis of sarcoidosis.

CONCLUSION

This case report illustrates the importance of continuously re-evaluating the diagnosis when new symptoms occur during the course of a rare disease. In the presence of pronounced lymphadenopathy, new hypercalcemia and lung parenchymal changes atypical for dermatomyositis, the differential diagnosis of sarcoidosis should also be considered.

Sarcoidosis: molecular mechanisms and therapeutic strategies

Sarcoidosis, a multisystemic granulomatous disease with unknown etiology, is characterized by formation of noncaseating granulomas, which can affect all organs. Recent studies have made outstanding achievement in understanding the pathology, etiology, genetics, and immune dysregulation involved in granuloma formation of sarcoidosis. Antigen stimulation in genetically predisposed individuals enhances the phagocytic activity of antigen-presenting cells, including macrophages and dendritic cells. CD4 + T cells initiate dysregulated immune responses and secrete significant quantities of inflammatory cytokines, including interleukin (IL)-2 and interferon-gamma (IFN-γ), which play a crucial role in modulating the aggregation and fusion of macrophages to form granulomas. The current therapeutic strategies focus on blocking the formation and spread of granulomas to protect organ function and alleviate symptoms. The efficacy of traditional treatments, such as glucocorticoids and immunosuppressants, has been confirmed in the management of sarcoidosis. Promising therapeutic agents encompass inhibitors of cytokines, like those targeting tumor necrosis factor (TNF)-α, as well as inhibitors of signaling pathways, such as Janus kinase (JAK) inhibitors, which exhibit favorable prospects for application. Although there has been progress in the identification of biomarkers for the diagnosis, prognosis, activity and severity of sarcoidosis, specific and sensitive biomarkers have yet to be identified. This review outlines recent advancements in the molecular mechanisms and therapeutic strategies for the sarcoidosis.

Diagnostic Value of Imaging and Serological Biomarkers in Pulmonary Sarcoidosis

Sarcoidosis is a multisystem granulomatous disease of an unknown aetiology. It can exist in many organs. Pulmonary and intrathoracic lymph nodes are most commonly involved. Lung sarcoidosis is uncommon in Asia. However, due to the large population of our country and the development of bronchoscopy, percutaneous lung puncture, and other medical technologies, the number of pulmonary sarcoidosis patients is on the rise. Pulmonary sarcoidosis patients have no obvious symptoms in the early stage, and the clinical manifestations in the later stage may vary from person to person. Eventually, the disease progresses to life-threatening pulmonary fibrosis. Therefore, patients with pulmonary sarcoidosis should receive a timely diagnosis. In recent years, the imaging features and serologic biomarkers of pulmonary sarcoidosis have been continuously studied. The diagnostic value of imaging and serologic biomarkers for pulmonary sarcoidosis is summarized below.

The causal relationship between sarcoidosis and autoimmune diseases: a bidirectional Mendelian randomization study in FinnGen

Background

Sarcoidosis has been considered to be associated with many autoimmune diseases (ADs), but the cause-and-effect relationship between these two diseases has not been fully explored. Therefore, the objective of this study is to explore the possible genetic association between sarcoidosis and ADs.

Methods

We conducted a bidirectional Mendelian randomization (MR) study using genetic variants associated with ADs and sarcoidosis (4,041 cases and 371,255 controls) from the FinnGen study. The ADs dataset comprised 96,150 cases and 281,127 controls, encompassing 44 distinct types of autoimmune-related diseases. Subsequently, we identified seven diseases within the ADs dataset with a case size exceeding 3,500 and performed subgroup analyses on these specific diseases.

Results

The MR evidence supported the causal association of genetic predictors of ADs with an increased risk of sarcoidosis (OR = 1.79, 95% CI = 1.59 to 2.02, P IVW-FE = 1.01 × 10-21), and no reverse causation (OR = 1.05, 95% CI 0.99 to 1.12, P IVW-MRE = 9.88 × 10-2). Furthermore, subgroup analyses indicated that genetic predictors of type 1 diabetes mellitus (T1DM), celiac disease, and inflammatory bowel disease (IBD) were causally linked to an elevated risk of sarcoidosis (All P < 6.25 × 10-3). Conversely, genetic predictors of sarcoidosis showed causal associations with a higher risk of type 1 diabetes mellitus (P < 6.25 × 10-3).

Conclusion

The present study established a positive causal relationship between genetic predictors of ADs (e.g. T1DM, celiac disease, and IBD) and the risk of sarcoidosis, with no evidence of reverse causation.

Infliximab in neurosarcoidosis: a systematic review and meta-analysis

OBJECTIVES

To evaluate the clinical outcomes and relapse rates in neurosarcoidosis patients administered infliximab.

METHODS

A systematic review was conducted using the MEDLINE, EMBASE, SCOPUS, and Cochrane Library databases. The search included studies from their inception to March 2023. We included case-series studies with at least 10 neurosarcoidosis patients undergoing any treatment type. Studies were also required to report at least one of the following outcomes: response rate, overall survival rate, or relapse rate. This study adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A random-effects model facilitated the analysis of proportional treatment outcomes. Study quality was evaluated using the modified Newcastle-Ottawa quality assessment scale, while a funnel plot helped detect any publication bias.

RESULTS

Seven studies comprising 237 patients with neurosarcoidosis were included in the analysis. Of these patients, 184 (77.6%) received treatment with infliximab. The pooled proportion of patients showing clinical improvement after infliximab treatment was 0.74 (95% CI 0.64-0.84, I2  = 49.73%). Relapse rates, derived from four studies, stood at 0.38 (95% CI 0.22-0.55, I2  = 56.92%). Most studies reported successful tapering or cessation of corticosteroid dosage in patients receiving infliximab. Adverse effects were reported in 52 (29.4%) patients, of which 39 out of 54 events (72.2%) were linked to infections.

INTERPRETATION

Infliximab demonstrated potential improvement in clinical outcomes for patients with refractory neurosarcoidosis and showed potential for reducing the dosage of concurrent corticosteroids. However, a degree of relapse was observed, with infections being the primary concern for adverse events.

Ocular Sarcoidosis and Autoimmune Polyglandular Syndrome Type 2: A Case Report

PURPOSE

to describe a clinical case of ocular sarcoidosis in a patient with Autoimmune Polyglandular Syndrome Type 2 (APS-2).

METHODS

an 86-year-old female diagnosed with APS-2 was referred to our uveitis department with rapid visual loss in her left eye during a 3-month period. Her best-corrected visual acuity (BCVA) was counting fingers in her left eye (OS) and 20/40 in her right eye (OD). Slit-lamp biomicroscopy was unremarkable OD but revealed granulomatous keratic precipitates OS. Fundoscopy revealed bilateral optic disc oedema and +2 and 4+ vitritis (SUN classification) in her OD and OS, respectively.

RESULTS

the patient underwent chest X-Ray which revealed bilateral hilar lymphadenopathy and fibrosis. On high-resolution computed tomography of the lungs, ground-glass opacities were visible, and a diagnosis of ocular sarcoidosis was presumed. After exclusion of infectious diseases, the patient was treated with methotrexate and oral corticosteroids and there was substantial improvement of the optic nerve oedema and vitritis. At the most recent visit, 2 years later, OS BCVA was 20/50.

CONCLUSION

There may be an association between ocular sarcoidosis and APS or other autoimmune disorders.

The Role of Small Airway Disease in Pulmonary Fibrotic Diseases

Small airway disease (SAD) is a pathological condition that affects the bronchioles and non-cartilaginous airways 2 mm or less in diameter. These airways play a crucial role in respiratory function and are often implicated in various pulmonary disorders. Pulmonary fibrotic diseases are characterized by the thickening and scarring of lung tissue, leading to progressive respiratory failure. We aimed to present the link between SAD and fibrotic lung conditions. The evidence suggests that SAD may act as a precursor or exacerbating factor in the progression of fibrotic diseases. Patients with fibrotic conditions often exhibit signs of small airway dysfunction, which can contribute to worsening respiratory symptoms and decreased lung function. Moreover, individuals with advanced SAD are at a heightened risk of developing fibrotic changes in the lung. The interplay between inflammation, environmental factors, and genetic predisposition further complicates this association. The early detection and management of SAD can potentially mitigate the progression of fibrotic diseases, highlighting the need for comprehensive clinical evaluation and research. This review emphasizes the need to understand the evolving connection between SAD and pulmonary fibrosis, urging further detailed research to clarify the causes and potential treatment between the two entities.

Sex differences in the genetics of sarcoidosis across European and African ancestry populations

Background

Sex differences in the susceptibility of sarcoidosis are unknown. The study aims to identify sex-dependent genetic variations in two clinical sarcoidosis phenotypes: Löfgren's syndrome (LS) and non-Löfgren's syndrome (non-LS).

Methods

A meta-analysis of genome-wide association studies was conducted on Europeans and African Americans, totaling 10,103 individuals from three population-based cohorts, Sweden (n = 3,843), Germany (n = 3,342), and the United States (n = 2,918), followed by an SNP lookup in the UK Biobank (UKB, n = 387,945). A genome-wide association study based on Immunochip data consisting of 141,000 single nucleotide polymorphisms (SNPs) was conducted in the sex groups. The association test was based on logistic regression using the additive model in LS and non-LS sex groups independently. Additionally, gene-based analysis, gene expression, expression quantitative trait loci (eQTL) mapping, and pathway analysis were performed to discover functionally relevant mechanisms related to sarcoidosis and biological sex.

Results

We identified sex-dependent genetic variations in LS and non-LS sex groups. Genetic findings in LS sex groups were explicitly located in the extended Major Histocompatibility Complex (xMHC). In non-LS, genetic differences in the sex groups were primarily located in the MHC class II subregion and ANXA11. Gene-based analysis and eQTL enrichment revealed distinct sex-specific gene expression patterns in various tissues and immune cell types. In LS sex groups, a pathway map related to antigen presentation machinery by IFN-gamma. In non-LS, pathway maps related to immune response lectin-induced complement pathway in males and related to maturation and migration of dendritic cells in skin sensitization in females were identified.

Conclusion

Our findings provide new evidence for a sex bias underlying sarcoidosis genetic architecture, particularly in clinical phenotypes LS and non-LS. Biological sex likely plays a role in disease mechanisms in sarcoidosis.

Autoimmune comorbidities associated with sarcoidosis: a case-control study in the All of Us research program

Objective

The degree to which sarcoidosis patients are affected by autoimmune diseases is poorly understood. Prior studies of autoimmune co-morbidities in sarcoidosis have focused on populations outside the USA or have been impeded by small sample sizes and limited scope. This case-control study evaluated the association between sarcoidosis and autoimmune diseases in a large, diverse cohort based in the USA.

Methods

We used data from the All of Us research programme to conduct a case-control study involving patients ≥18 years old, from 2018 to the present, diagnosed with sarcoidosis. Sarcoidosis cases and age-, sex- and race-matched controls were identified in a 1:4 ratio. Autoimmune co-morbidities were compared between sarcoidosis patients and controls in univariable and multivariable analyses using logistic regression. The degree of association was measured using the odds ratio (OR).

Results

A total of 1408 sarcoidosis cases and 5632 controls were included in this study. Seven of 24 examined autoimmune diseases were significantly associated with sarcoidosis in our multivariable analysis (P < 0.05). The composite variable of any autoimmune disease was also significantly associated with sarcoidosis (OR = 2.29, P < 0.001).

Conclusion

We demonstrate an association between sarcoidosis and multiple autoimmune diseases in a large and diverse cohort based in the USA. These results underscore the need for careful screening of sarcoidosis patients for concomitant autoimmune disease.

Mycobacterial Heat Shock Proteins in Sarcoidosis and Tuberculosis

Pathological similarities between sarcoidosis (SA) and tuberculosis (TB) suggest the role of mycobacterial antigens in the etiopathogenesis of SA. The Dubaniewicz group revealed that not whole mycobacteria, but Mtb-HSP70, Mtb-HSP 65, and Mtb-HSP16 were detected in the lymph nodes, sera, and precipitated immune complexes in patients with SA and TB. In SA, the Mtb-HSP16 concentration was higher than that of Mtb-HSP70 and that of Mtb-HSP65, whereas in TB, the Mtb-HSP16 level was increased vs. Mtb-HSP70. A high Mtb-HSP16 level, induced by low dose-dependent nitrate/nitrite (NOx), may develop a mycobacterial or propionibacterial genetic dormancy program in SA. In contrast to TB, increased peroxynitrite concentration in supernatants of peripheral blood mononuclear cell cultures treated with Mtb-HSP may explain the low level of NOx detected in SA. In contrast to TB, monocytes in SA were resistant to Mtb-HSP-induced apoptosis, and CD4+T cell apoptosis was increased. Mtb-HSP-induced apoptosis of CD8+T cells was reduced in all tested groups. In Mtb-HSP-stimulated T cells, lower CD8+γδ+IL-4+T cell frequency with increased TNF-α,IL-6,IL-10 and decreased INF-γ,IL-2,IL-4 production were present in SA, as opposed to an increased presence of CD4+γδ+TCR cells with increased TNF-α,IL-6 levels in TB, vs. controls. Mtb-HSP modulating the level of co-stimulatory molecules, regulatory cells, apoptosis, clonal deletion, epitope spread, polyclonal activation and molecular mimicry between human and microbial HSPs may also participate in the induction of autoimmunity, considered in SA. In conclusion, in different genetically predisposed hosts, the same antigens, e.g., Mtb-HSP, may induce the development of TB or SA, including an autoimmune response in sarcoidosis.

Adalimumab in the treatment of cardiac sarcoidosis: Single center case series and narrative literature review

Background

Tumor necrosis factor (TNF) inhibitors have been used in the treatment of cardiac sarcoidosis, infliximab being the most commonly used. We have previously reported a case of effective treatment of cardiac sarcoidosis using adalimumab.

Objective

To describe our experience of using adalimumab in the treatment of cardiac sarcoidosis.

Methods

We conducted a retrospective study to evaluate patients with cardiac sarcoidosis who received adalimumab treatment at the University of Illinois Health between 2011 and 2022. The outcome was evaluated by assessing safety, tolerability, and ability to taper systemic corticosteroids therapy following initiation of adalimumab.

Results

Seven patients met the inclusion criteria. Clinical responses to adalimumab were universally positive. Corticosteroid therapy was discontinued in five patients and the dose was reduced in two patients. Furthermore, adalimumab was well tolerated, and no adverse events were reported.

Conclusion

Adalimumab was safe and well-tolerated in seven patients with cardiac sarcoidosis seen at our medical center and exhibited corticosteroid-sparing effects. Our observation further warrants large prospective studies to evaluate the safety and efficacy of adalimumab in the treatment of cardiac sarcoidosis.

Autoimmune pulmonary alveolar proteinosis and sarcoidosis in the same patient: Case report and systematic review

Pulmonary alveolar proteinosis (PAP) is a rare pulmonary disorder characterized by surfactant accumulation in the alveolar spaces while sarcoidosis is a multisystem granulomatous disease of unknown etiology. The occurrence of PAP and sarcoidosis in the same patient is rare. A 37-year-old woman presented with cough and breathlessness and was diagnosed to have autoimmune PAP. She responded well to subcutaneous injections of recombinant granulocyte macrophage colony stimulating factor. Three years later, she developed fever, chest pain, cough, and facial palsy. The evaluation revealed a diagnosis of sarcoidosis that responded to immunosuppressive treatment. We discuss the link between PAP and sarcoidosis and review the literature on this association.

Atypical and uncommon presentation of sarcoidosis with long segment involvement of the pharynx and larynx: Case report and review of literature

Pharynx/Larynx is an uncommon site of involvement of sarcoidosis. Isolated pharyngo-laryngeal sarcoidosis is extremely rare as most of the cases are part from multiorgan and systemic sarcoidosis. Pharyngo-laryngeal sarcoidosis is usually asymptomatic which could be attributed to its rare incidence as many cases pass unnoticed. Symptomatic cases usually present with hoarseness of voice. As the disease progress, the patient can present with progressive dysphagia to solid and liquid with globus sensation. We described an atypical involvement of almost the whole length of the pharynx with extension into the larynx in a 51-year-old woman who presented with progressive dysphagia. To the best of our knowledge, this is the first report to describe the imaging features of sarcoidosis involvement of the pharynx and larynx.

Autoimmune Disease Classification Based on PubMed Text Mining

Autoimmune diseases (AIDs) are often co-associated, and about 25% of patients with one AID tend to develop other comorbid AIDs. Here, we employ the power of datamining to predict the comorbidity of AIDs based on their normalized co-citation in PubMed. First, we validate our technique in a test dataset using earlier-reported comorbidities of seven knowns AIDs. Notably, the prediction correlates well with comorbidity (R = 0.91) and validates our methodology. Then, we predict the association of 100 AIDs and classify them using principal component analysis. Our results are helpful in classifying AIDs into one of the following systems: (1) gastrointestinal, (2) neuronal, (3) eye, (4) cutaneous, (5) musculoskeletal, (6) kidneys and lungs, (7) cardiovascular, (8) hematopoietic, (9) endocrine, and (10) multiple. Our classification agrees with experimentally based taxonomy and ranks AID according to affected systems and gender. Some AIDs are unclassified and do not associate well with other AIDs. Interestingly, Alzheimer's disease correlates well with other AIDs such as multiple sclerosis. Finally, our results generate a network classification of autoimmune diseases based on PubMed text mining and help map this medical universe. Our results are expected to assist healthcare workers in diagnosing comorbidity in patients with an autoimmune disease, and to help researchers in identifying common genetic, environmental, and autoimmune mechanisms.

The Evolving Landscape of Cutaneous Sarcoidosis: Pathogenic Insight, Clinical Challenges, and New Frontiers in Therapy

Sarcoidosis is a multisystem disorder of unknown etiology characterized by accumulation of granulomas in affected tissue. Cutaneous manifestations are among the most common extrapulmonary manifestations in sarcoidosis and can lead to disfiguring disease requiring chronic therapy. In many patients, skin disease may be the first recognized manifestation of sarcoidosis, necessitating a thorough evaluation for systemic involvement. Although the precise etiology of sarcoidosis and the pathogenic mechanisms leading to granuloma formation, persistence, or resolution remain unclear, recent research has led to significant advances in our understanding of this disease. This article reviews recent advances in epidemiology, sarcoidosis clinical assessment with a focus on the dermatologist's role, disease pathogenesis, and new therapies in use and under investigation for cutaneous and systemic sarcoidosis.

Sjögren’s Syndrome Complicated With Sarcoidosis With a Repetitive, Prolonged, Non-productive Cough

Sjögren's syndrome and sarcoidosis are systemic immune-mediated diseases of unresolved pathogenesis, with dry cough being a symptom of both diseases. Due to the low pre-test probability of the diseases, they are not considered in the first differential diagnosis of prolonged non-productive cough. We report the case of a 33-year-old woman presenting with an intermittent, non-productive cough, diagnosed with Sjögren’s syndrome coexisting with sarcoidosis.