HLA-DRB1*1101: a significant risk factor for sarcoidosis in blacks and whites

Insights into the diagnosis and management of sarcoid uveitis: A review

Sarcoidosis is a leading cause of non-infectious uveitis that commonly affects middle-aged individuals and has a female preponderance. The disease demonstrates age, sex and ethnic differences in clinical manifestations. A diagnosis of sarcoidosis is made based on a compatible clinical presentation, supporting investigations and histologic evidence of non-caseating granulomas, although biopsy is not always possible. Multimodal imaging with widefield fundus photography, optical coherence tomography and angiography can help in the diagnosis of sarcoid uveitis and in the monitoring of treatment response. Corticosteroid remains the mainstay of treatment; chronic inflammation requires steroid-sparing immunosuppression. Features on multimodal imaging such as vascular leakage may provide prognostic indicators of outcome. Female gender, prolonged and severe uveitis, and posterior involving uveitis are associated with poorer visual outcomes.

Granulomatous liver diseases

A granuloma is a discrete collection of activated macrophages and other inflammatory cells. Hepatic granulomas can be a manifestation of localized liver disease or be a part of a systemic process, usually infectious or autoimmune. A liver biopsy is required for the detection and evaluation of granulomatous liver diseases. The prevalence of granulomas on liver biopsy varies from 1% to 15%. They may be an incidental finding in an asymptomatic individual, or they may represent granulomatous hepatitis with potential to progress to liver failure, or in chronic disease, to cirrhosis. This review focuses on pathogenesis, histological features of granulomatous liver diseases, and most common etiologies, knowledge that is essential for timely diagnosis and intervention.

HLA Gene Polymorphisms in Romanian Patients with Chronic Lymphocytic Leukemia

Materials and Methods

This study included 66 patients with CLL, diagnosed between 2020 and 2022, and 100 healthy controls. HLA class I and class II genes (HLA-A/B/C, HLA-DQA1/DQB1/DPA1/DPB1, and HLA-DRB1/3/4/5) were investigated using next-generation sequencing technology.

Results

Several HLA alleles were strongly associated with CLL. The most important finding was that HLA-DRB1∗04:02:01 (p=0.001, OR = 1.05) and HLA-DRB3∗02:01:01 (p=0.009, OR = 1.03) have a predisposing role in CLL development. Moreover, we identified that HLA-A∗24:02:01 0.01 (p=0.01, OR = 0.38), HLA-DQA1∗05:05:01 (p=0.01, OR = 0.56), HLA-DQB1∗03:02:01 (p=0.03, OR = 0.40), and HLA-DRB4∗01:03:01 (p=0.03, OR = 0.54 alleles have protective roles. Correlations between HLA expression and gender showed that women had a higher expression of protective HLA alleles when compared to men.

Conclusions

Our data are the first to indicate that in Romanian patients with CLL, the HLA-A∗24:02:01 and HLA-DQA1∗05:05:01 alleles have a protective role against CLL development, whereas HLA-DRB1∗04:02:01 and HLA-DRB3∗02:01:01alleles are positively associated with CLL.

Immune mechanisms of granuloma formation in sarcoidosis and tuberculosis

Sarcoidosis is a complex immune-mediated disease characterized by clusters of immune cells called granulomas. Despite major steps in understanding the cause of this disease, many questions remain. In this Review, we perform a mechanistic interrogation of the immune activities that contribute to granuloma formation in sarcoidosis and compare these processes with its closest mimic, tuberculosis, highlighting shared and divergent immune activities. We examine how Mycobacterium tuberculosis is sensed by the immune system; how the granuloma is initiated, formed, and perpetuated in tuberculosis compared with sarcoidosis; and the role of major innate and adaptive immune cells in shaping these processes. Finally, we draw these findings together around several recent high-resolution studies of the granuloma in situ that utilized the latest advances in single-cell technology combined with spatial methods to analyze plausible disease mechanisms. We conclude with an overall view of granuloma formation in sarcoidosis.

Clinical Manifestations and Management of Fibrotic Pulmonary Sarcoidosis

Fibrotic pulmonary sarcoidosis represents a distinct and relatively uncommon manifestation within the spectrum of sarcoidosis and has substantial morbidity and mortality. Due to the scarcity of research focused on this specific disease subtype, our current understanding of pathogenesis and optimal management remains constrained. This knowledge gap underscores the need for further investigation into areas such as targeted therapies, lung transplantation, and quality of life of patients with fibrotic pulmonary sarcoidosis. The primary aim of this review is to discuss recent developments within the realm of fibrotic pulmonary sarcoidosis to foster a more comprehensive understanding of the underlying mechanisms, prognosis, and potential treatment modalities.

Examination of eQTL Polymorphisms Associated with Increased Risk of Progressive Complicated Sarcoidosis in European and African Descent Subjects

Background

A limited pool of SNPs are linked to the development and severity of sarcoidosis, a systemic granulomatous inflammatory disease. By integrating genome-wide association studies (GWAS) data and expression quantitative trait loci (eQTL) single nuclear polymorphisms (SNPs), we aimed to identify novel sarcoidosis SNPs potentially influencing the development of complicated sarcoidosis.

Methods

A GWAS (Affymetrix 6.0) involving 209 African-American (AA) and 193 European-American (EA, 75 and 51 complicated cases respectively) and publicly-available GWAS controls (GAIN) was utilized. Annotation of multi-tissue eQTL SNPs present on the GWAS created a pool of ~46,000 eQTL SNPs examined for association with sarcoidosis risk and severity (Logistic Model, Plink). The most significant EA/AA eQTL SNPs were genotyped in a sarcoidosis validation cohort (n=1034) and cross-validated in two independent GWAS cohorts.

Results

No single GWAS SNP achieved significance (p<1x10-8), however, analysis of the eQTL/GWAS SNP pool yielded 621 eQTL SNPs (p<10-4) associated with 730 genes that highlighted innate immunity, MHC Class II, and allograft rejection pathways with multiple SNPs validated in an independent sarcoidosis cohort (105 SNPs analyzed) (NOTCH4, IL27RA, BTNL2, ANXA11, HLA-DRB1). These studies confirm significant association of eQTL/GWAS SNPs in EAs and AAs with sarcoidosis risk and severity (complicated sarcoidosis) involving HLA region and innate immunity.

Conclusion

Despite the challenge of deciphering the genetic basis for sarcoidosis risk/severity, these results suggest that integrated eQTL/GWAS approaches may identify novel variants/genes and support the contribution of dysregulated innate immune responses to sarcoidosis severity.

Human leukocyte antigen-DQ risk heterodimeric haplotypes of left ventricular dysfunction in cardiac sarcoidosis: an autoimmune view of its role

Cardiac sarcoidosis (CS) is the scarring of heart muscles by autoimmunity, leading to heart abnormalities and patients with sarcoidosis with cardiac involvements have poor prognoses. Due to the small number of patients, it is difficult to stratify all patients of CS by human leukocyte antigen (HLA) analysis. We focused on the structure of antigen-recognizing pockets in heterodimeric HLA-class II, in addition to DNA sequences, and extracted high-affinity combinations of antigenic epitopes from candidate autoantigen proteins and HLA. Four HLA heterodimer-haplotypes (DQA1*05:03/05:05/05:06/05:08-DQB1*03:01) were identified in 10 of 68 cases. Nine of the 10 patients had low left ventricular ejection fraction (< 50%). Fourteen amino-acid sequences constituting four HLA anchor pockets encoded by the HLA haplotypes were all common, suggesting DQA1*05:0X-DQB1*03:01 exhibit one group of heterodimeric haplotypes. The heterodimeric haplotypes recognized eight epitopes from different proteins. Assuming that autoimmune mechanisms might be activated by molecular mimicry, we searched for bacterial species having peptide sequences homologous to the eight epitopes. Within the peptide epitopes form the SLC25A4 and DSG2, high-homology sequences were found in Cutibacterium acnes and Mycobacterium tuberculosis, respectively. In this study, we detected the risk heterodimeric haplotypes of ventricular dysfunction in CS by searching for high-affinity HLA-class II and antigenic epitopes from candidate cardiac proteins.

Genetic predisposition to sarcoidosis

Sarcoidosis is a complex systemic disease with clinical heterogeneity based on varying phenotypes and natural history. The detailed etiology of sarcoidosis remains unknown, but genetic predisposition as well as environmental exposures play a significant role in disease pathogenesis. We performed a comprehensive review of germline genetic (DNA) and transcriptomic (RNA) studies of sarcoidosis, including both previous studies and more recent findings. In this review, we provide an assessment of the following: genetic variants in sarcoidosis susceptibility and phenotypes, ancestry- and sex-specific genetic variants in sarcoidosis, shared genetic architecture between sarcoidosis and other diseases, and gene-environment interactions in sarcoidosis. We also highlight the unmet needs in sarcoidosis genetic studies, including the pressing requirement to include diverse populations and have consistent definitions of phenotypes in the sarcoidosis research community to help advance the application of genetic predisposition to sarcoidosis disease risk and manifestations.

Pulmonary sarcoidosis: A comprehensive review: Past to present

Sarcoidosis is a sterile non-necrotizing granulomatous disease without known causes that can involve multiple organs with a predilection for the lung and thoracic lymph nodes. Worldwide it is estimated to affect 2-160/100,000 people and has a mortality rate over 5 years of approximately 7%. For sarcoidosis patients, the cause of death is due to sarcoid in 60% of the cases, of which up to 80% are from advanced cardiopulmonary failure (pulmonary hypertension and respiratory microbial infections) in all races except in Japan were greater than 70% of the sarcoidosis deaths are due to cardiac sarcoidosis. Scadding stages for pulmonary sarcoidosis associates with clinical outcomes. Stages I and II have radiographic remission in approximately 30%-80% of cases. Stage III only has a 10%-40% chance of resolution, while stage IV has no change of resolution. Up to 40% of pulmonary sarcoidosis patients progress to stage IV disease with lung parenchyma fibroplasia, bronchiectasis with hilar retraction and fibrocystic disease. These patients are at highest risk for the development of precapillary pulmonary hypertension, which may occur in up to 70% of these patients. Sarcoid patients with pre-capillary pulmonary hypertension can respond to targeted pulmonary arterial hypertension medications. Stage IV fibrocytic sarcoidosis with significant pulmonary physiologic impairment, >20% fibrosis on HRCT or pre-capillary pulmonary hypertension have the highest risk of mortality, which can be >40% at 5-years. First line treatment for patients who are symptomatic (cough and dyspnea) with parenchymal infiltrates and abnormal pulmonary function testing (PFT) is oral glucocorticoids, such as prednisone with a typical starting dose of 20-40 mg daily for 2 weeks to 2 months. Prednisone can be tapered over 6-18 months if symptoms, spirometry, PFTs, and radiographs improve. Prolonged prednisone may be required to stabilize disease. Patients requiring prolonged prednisone ≥10 mg/day or those with adverse effects due to glucocorticoids may be prescribed second and third line treatements. Second and third line treatments include immunosuppressive agents (e.g., methotrexate and azathioprine) and anti-tumor necrosis factor (TNF) medication; respectively. Effective treatments for advanced fibrocystic pulmonary disease are being explored. Despite different treatments, relapse rates range from 13% to 75% depending on the stage of sarcoid, number of organs involved, socioeconomic status, and geography. CONCLUSION: The mortality rate for sarcoidosis over a 5 year follow up is approximately 7%. Unfortunately, 10%-40% of patients with sarcoidosis develop progressive pulmonary disease, and >60% of deaths resulting from sarcoidosis are due to advance cardiopulmonary disease. Oral glucocorticoids are the first line treatment, while methotrexate and azathioprine are considered second and anti-TNF agents are third line treatments that are used solely or as glucocorticoid sparing agents for symptomatic extrapulmonary or pulmonary sarcoidosis with infiltrates on chest radiographs and abnormal PFT. Relapse rates have ranged from 13% to 75% depending on the population studied.

Peripheral blood lymphopenia in sarcoidosis associates with HLA-DRB1 alleles but not with lung immune cells and organ involvement

Different human leukocyte antigen (HLA) alleles associate with disease phenotypes in sarcoidosis. Peripheral blood (PB) lymphopenia is reported as more common in sarcoidosis patients with worse prognosis. The mechanisms behind are unrecognized but a PB depletion due to lymphocytes migrating to lung and/or extra pulmonary organs has been suggested. Insights into associations between HLA alleles, lung immune cells, clinical phenotype including extra pulmonary manifestations (EPM), and PB lymphopenia may provide mechanistic clues and enable adequate intervention in this patient group. In this situdy,141 treatment naïve, newly diagnosed patients were retrospectively identified in a Swedish cohort of sarcoidosis patients. Data on HLA-DRB1 alleles, lung immune cells from bronchoalveolar lavage fluid (BALF), PB lymphocytes and clinical parameters including treatment and disease course (chronic vs. resolving) were collected. The patients were followed for 2 years. PB lymphopenia associated with male sex, development of non-resolving disease, a need for first- and second-line systemic immunosuppressant treatment and HLA- DRB1*07. No correlation between BALF and PB lymphocytes, and no difference in EPM was detected between patients with and without PB lymphopenia. In conclusion, PB lymphopenia is associated with a more severe disease phenotype and carriage of the HLA-DRB1*07 allele. The results do not lend support to the hypothesis about sarcoidosis PB lymphopenia being due to a migration of PB lymphocytes to other organs. Rather, they provide a basis for future studies on the connection between HLA-DRB1*07 and PB lymphopenia mechanisms.

Identification of Environmental Exposures Associated with Risk of Sarcoidosis in African Americans

Rationale: Sarcoidosis is a racially disparate granulomatous disease likely caused by environmental exposures, genes, and their interactions. Despite increased risk in African Americans, few environmental risk factor studies in this susceptible population exist. Objectives: To identify environmental exposures associated with the risk of sarcoidosis in African Americans and those that differ in effect by self-identified race and genetic ancestry. Methods: The study sample comprised 2,096 African Americans (1,205 with and 891 without sarcoidosis) compiled from three component studies. Unsupervised clustering and multiple correspondence analyses were used to identify underlying clusters of environmental exposures. Mixed-effects logistic regression was used to evaluate the association of these exposure clusters and the 51 single-component exposures with risk of sarcoidosis. A comparison case-control sample of 762 European Americans (388 with and 374 without sarcoidosis) was used to assess heterogeneity in exposure risk by race. Results: Seven exposure clusters were identified, five of which were associated with risk. The exposure cluster with the strongest risk association was composed of metals (P < 0.001), and within this cluster, exposure to aluminum had the highest risk (odds ratio, 3.30; 95% confidence interval [95% CI], 2.23-4.09; P < 0.001). This effect also differed by race (P < 0.001), with European Americans having no significant association with exposure (odds ratio, 0.86; 95% CI, 0.56-1.33). Within African Americans, the increased risk was dependent on genetic African ancestry (P = 0.047). Conclusions: Our findings support African Americans having sarcoidosis environmental exposure risk profiles that differ from those of European Americans. These differences may underlie racially disparate incidence rates that are partially explained by genetic variation differing by African ancestry.

Genome-wide association study identifies multiple HLA loci for sarcoidosis susceptibility

Sarcoidosis is a complex systemic disease. Our study aimed to (1) identify novel alleles associated with sarcoidosis susceptibility; (2) provide an in-depth evaluation of HLA alleles and sarcoidosis susceptibility and (3) integrate genetic and transcription data to identify risk loci that may more directly impact disease pathogenesis. We report a genome-wide association study of 1335 sarcoidosis cases and 1264 controls of European descent (EA) and investigate associated alleles in a study of African Americans (AA: 1487 cases and 1504 controls). The EA and AA cohort was recruited from multiple United States sites. HLA alleles were imputed and tested for association with sarcoidosis susceptibility. Expression quantitative locus and colocalization analysis were performed using a subset of subjects with transcriptome data. Forty-nine SNPs in the HLA region in HLA-DRA, -DRB9, -DRB5, -DQA1 and BRD2 genes were significantly associated with sarcoidosis susceptibility in EA, rs3129888 was also a risk variant for sarcoidosis in AA. Classical HLA alleles DRB1*0101, DQA1*0101 and DQB1*0501, which are highly correlated, were also associated with sarcoidosis. rs3135287 near HLA-DRA was associated with HLA-DRA expression in peripheral blood mononuclear cells and bronchoalveolar lavage from subjects and lung tissue and whole blood from GTEx. We identified six novel SNPs (out of the seven SNPs representing the 49 significant SNPs) and nine HLA alleles associated with sarcoidosis susceptibility in the largest EA population. We also replicated our findings in an AA population. Our study reiterates the potential role of antigen recognition and/or presentation HLA class II genes in sarcoidosis pathogenesis.

An unusual case of oral sarcoidosis: A diagnostic dilemma

Sarcoidosis is a rare type of multi-organ granulomatous disease. It is characterised by non-caseating necrotising granulomatous inflammation. The exact mechanism causing the disease is unknown due to its variation of manifestation in patients. The clinical presentation of this disease is protean, and often, patients remain asymptomatic throughout life. The most commonly affected organ by sarcoidosis is the lung accounting for up to 90% of all cases. Oral manifestation is a relatively rare presentation of sarcoidosis, and there are only a few cases reported till date. In this case report, the authors present a case of oral sarcoidosis of the retromolar trigone region.

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.

Sarcoidosis and Autoimmune Inflammatory Syndrome Induced by Adjuvants

Currently, sarcoidosis remains one of the diseases with unknown etiology, which significantly complicates its diagnosis and treatment. Various causes of sarcoidosis have been studied for many years. Both organic and inorganic trigger factors, provoking the development of granulomatous inflammation are considered. However, the most promising and evidence-based hypothesis is the development of sarcoidosis as an autoimmune disease, provoked by various adjuvants in genetic predisposed individuals. This concept fits into the structure of the autoimmune/inflammatory syndrome, induced by adjuvants (ASIA) that was proposed in 2011 by Professor Shoenfeld Y. In this paper, the authors reveal the presence of major and minor ASIA criteria for sarcoidosis, propose a new concept of the course of sarcoidosis within the framework of ASIA, and point out the difficulties in creating a model of the disease and the selection of therapy. It is obvious that the data obtained not only bring us closer to understanding the nature of sarcoidosis, but also potentiate new studies confirming this hypothesis by obtaining a model of the disease.

Sarcoidosis, Mycobacterium paratuberculosis and Noncaseating Granulomas: Who Moved My Cheese

Clinical and histological similarities between sarcoidosis and tuberculosis have driven repeated investigations looking for a mycobacterial cause of sarcoidosis. Over 50 years ago, "anonymous mycobacteria" were suggested to have a role in the etiology of sarcoidosis. Both tuberculosis and sarcoidosis have a predilection for lung involvement, though each can be found in any area of the body. A key histopathologic feature of both sarcoidosis and tuberculosis is the granuloma-while the tuberculous caseating granuloma has an area of caseous necrosis with a cheesy consistency; the non-caseating granuloma of sarcoidosis does not have this feature. This article reviews and reiterates the complicity of the infectious agent, Mycobacterium avium subsp. paratuberculosis (MAP) as a cause of sarcoidosis. MAP is involved in a parallel story as the putative cause of Crohn's disease, another disease featuring noncaseating granulomas. MAP is a zoonotic agent infecting ruminant animals and is found in dairy products and in environmental contamination of water and air. Despite increasing evidence tying MAP to several human diseases, there is a continued resistance to embracing its pleiotropic roles. "Who Moved My Cheese" is a simple yet powerful book that explores the ways in which individuals react to change. Extending the metaphor, the "non-cheesy" granuloma of sarcoidosis actually contains the difficult-to-detect "cheese", MAP; MAP did not move, it was there all along.

Sarcoidosis

Sarcoidosis is a disease of unknown cause characterized by granulomatous inflammation. Although the lung is almost universally involved, any organ can be affected. Complex pathogenesis and protean clinical manifestations are additional features of the disease. The diagnosis is one of exclusion, although the presence of noncaseating granulomas at disease sites is a prerequisite in most cases. The management of sarcoidosis requires a multidisciplinary approach, particularly when the heart, the brain, or the eyes are involved. The paucity of effective therapies and the lack of reliable predictors of disease behavior greatly contribute to making sarcoidosis a challenging disease to manage.

FDG PET/CT Imaging of Sarcoidosis

Sarcoidosis is a multisystemic granulomatous disease of unknown etiology. The diagnostic can be made by histological identification of non-caseous granuloma or by a combination of clinical criteria. Active inflammatory granuloma can lead to fibrotic damage. Although 50% of cases resolve spontaneously, systemic treatments are often necessary to decrease symptoms and avoid permanent organ dysfunction, notably in cardiac sarcoidosis. The course of the disease can be punctuated by exacerbations and relapses and the prognostic depends mainly on affected sites and patient management. FDG-PET/CT along with newer FDG-PET/MR have emerged as key imaging modalities in sarcoidosis, namely for certain diagnostic purposes, staging and biopsy guiding. By identifying with a high sensitivity inflammatory active granuloma, FDG hybrid imaging is a main prognostic tool and therapeutic ally in sarcoidosis. This review aims to highlight the actual critical roles of hybrid PET imaging in sarcoidosis and display a brief perspective for the future which appears to include other radiotracers and artificial intelligence applications.

Whole Exome Sequencing Identified Two Single Nucleotide Polymorphisms of Human Leukocyte Antigen-DRB5 in Familial Sarcoidosis in China

BACKGROUND

Sarcoidosis is a multisystem granulomatous disorder whose etiology is related to genetic and immunological factors. Familial aggregation and ethnic prevalence suggest a genetic predisposition and inherited susceptibility to sarcoidosis.

OBJECTIVE

This study aimed to identify suspected risk loci for familial sarcoidosis patients.

METHODS

We conducted whole exome sequencing on two sarcoidosis patients and five healthy family members in a Chinese family for a case-control study. The two sarcoidosis patients were siblings who showed chronic disease.

RESULTS

The Gene Ontology results showed single nucleotide polymorphisms in three genes, including human leukocyte antigen (HLA)-DRB1, HLA-DRB5, and KIR2DL4, associated with both 'antigen processing and presentation' and 'regulation of immune response.' Sanger sequencing verified two nonsynonymous mutations in HLA-DRB5 (rs696318 and rs115817940) located on 6p21.3 in the major histocompatibility complex (MHC) class II beta 1 region. The structural model simulated on Prot- Param protein analysis by the Expert Protein Analysis System predicted that the hydropathy index changed at two mutation sites (rs696318: p.F96L, -1.844 to -1.656 and rs115817940: p.T106N, -0.322 to -0.633), which indicated the probability of changes in peptide-binding selectivity.

CONCLUSION

Our results indicated that two nonsynonymous mutations of HLA-DRB5 have been identified in two sarcoidosis siblings, while their healthy family members do not have the mutations. The two HLA-DRB5 alleles may influence genetic susceptibility and chronic disease progression through peptide mutations on the MHC class II molecule among the two affected family members.

Association between sarcoidosis and HLA polymorphisms in a Czech population from Central Europe: focus on a relationship with clinical outcome and treatment

Background

Sarcoidosis is an immune-mediated systemic disease with unknown etiology affecting the lung predominantly. The clinical manifestation of sarcoidosis is rather diverse ranging from Löfgren's syndrome to fibrotic disease. Also, it differs among patients with distinct geographical and ethnic origins, consistent with environmental and genetic factors' role in its pathogenesis. Of those, the polymorphic genes of the HLA system have been previously implicated in sarcoidosis. Therefore, we have performed an association study in a well-defined cohort of Czech patients aiming to define how variation in HLA genes, may contribute to disease origin and development.

Materials and methods

Total of the 301 Czech unrelated sarcoidosis patients were diagnosed according to international guidelines. In those, HLA typing was performed using next-generation sequencing. The allele frequencies at six HLA loci (HLA-A,-B,-C,-DRB1,-DQA1, and -DQB1) observed in the patients were compared with HLA allele distribution determined in 309 unrelated healthy Czech subjects; sub-analyses of relationships between HLA and distinct sarcoidosis clinical phenotypes were performed. Associations were assessed by two-tailed Fischer's exact test with correction for multiple comparisons.

Results

We report two variants, HLA-DQB1*06:02, and HLA-DQB1*06:04, as risk factors for sarcoidosis, and three variants, HLA-DRB1*01:01, HLA-DQA1*03:01, and HLA-DQB1*03:02 as protective factors. HLA-B*08:01, HLA-C*07:01, HLA-DRB1*03:01, HLA-DQA1*05:01, and HLA-DQB1*02:01 variants associated with Löfgren's syndrome, a more benign phenotype. HLA- DRB1*03:01 and HLA-DQA1*05:01 alleles were connected with better prognosis-chest X-ray (CXR) stage 1, disease remission, and non-requirement of corticosteroid treatment. The alleles HLA-DRB1*11:01 and HLA-DQA1*05:05 are associated with more advanced disease represented by the CXR stages 2-4. HLA-DQB1*05:03 associated with sarcoidosis extrapulmonary manifestation.

Conclusion

In our Czech cohort, we document some associations between sarcoidosis and HLA previously described in other populations. Further, we suggest novel susceptibility factors for sarcoidosis, such as HLA-DQB1*06:04, and characterize associations between HLA and sarcoidosis clinical phenotypes in Czech patients. Our study also extends the role of the 8.1 ancestral haplotype (HLA-A*01:01∼HLA-B*08:01∼HLA-C*07:01∼HLA-DRB1*03:01∼HLA-DQA1*05:01∼HLA-DQB1*02:01), already implicated in autoimmune diseases, as a possible predictor of better prognosis in sarcoidosis. The general translational application of our newly reported findings for personalized patient care should be validated by an independent study from another, international referral center.

Neurosarcoidosis in children: A systematic review and summary of cases, imaging and management

Neurosarcoidosis is a rare disorder in children. We identified 30 pediatric NS cases through a systematic review. Twenty-one (70%) had systemic sarcoidosis with 30% having primary neurosarcoidosis. Eyes (37%), lymph nodes (37%) and lungs (30%) were most commonly involved. Isolated neurosarcoidosis were more likely in children (30%) than in adults (6%, p = 0.0005). Seizures and optic neuritis were also more common in children than adults (33% vs 14%, p = 0.002; and 30% versus 6%, p = 0.008, respectively). Evaluation, imaging, laboratory findings, and treatments are discussed. Additional research, including multi-center studies, is needed.

Renal sarcoidosis

Renal sarcoidosis (RS) is a rare form of sarcoidosis that results in granulomatous inflammation of renal parenchyma. We describe the epidemiology, pathogenesis, clinical features, diagnostic approach, treatment strategies and outcomes of this condition. RS occurs most commonly at the time of initial presentation of sarcoidosis but can at any time along the course of the disease. The most common presenting clinical manifestations of RS are renal insufficiency or signs of general systemic inflammation. End-stage renal disease requiring dialysis is a rare initial presentation of RS. The diagnosis of RS should be considered in patients who present with renal failure and have either a known diagnosis of sarcoidosis or have extra-renal features consistent with sarcoidosis. A renal biopsy helps to establish the diagnosis of RS, with interstitial non-caseating granulomas confined primarily to the renal cortex being the hallmark pathological finding. However, these histologic findings are not specific for sarcoidosis, and alternative causes for granulomatous inflammation of the renal parenchyma should be excluded. Corticosteroids are the drug of choice for RS. Although RS usually responds well to corticosteroids, the disease may have a chronic course and require long-term immunosuppressive therapy. The risk of progression to ESRD is rare.

Prevalence of Positive QuantiFERON-TB Test among Sarcoid Uveitis Patients and its Clinical Implications in a Country Non-endemic for Tuberculosis

AIM

To report on the prevalence and clinical implications of positive QuantiFERON-TB (QFT) test results in the diagnostic evaluation of a cohort of consecutive sarcoid uveitis patients in France.

DESIGN

Retrospective cross-sectional study.

METHODS

This study included consecutive sarcoid uveitis patients who all underwent QFT testing.

RESULTS

A total of 234 patients were included in the study, among them 28 (12%) were QFT-positive. Previously treated tuberculosis (TB) was documented in 2 patients. QFT-positive patients were older (59 ± 16 years vs. 51 ± 18 years, p = .025) and more in proportion to suffer from chronic uveitis and panuveitis compared to QFT-negative patients. Moderate and severe visual impairment were significantly more frequent in the QFT-positive group (35.7% vs. 18.9%, p = .049 and 25.0% vs. 9.2%, p = .022, respectively).

CONCLUSION

The significant proportion of QFT-positive patients (12%) in this large series of sarcoid uveitis patients makes us suggest not to exclude the diagnosis of sarcoidosis in case of positive QFT in a low-endemic country for tuberculosis, and to manage these patients early by initiating without delay systemic steroids associated with latent tuberculosis therapy.

Sarcoid Uveitis: An Intriguing Challenger

The purpose of our work is to describe the actual knowledge concerning etiopathogenesis, clinical manifestations, diagnostic procedures, complications and therapy of ocular sarcoidosis (OS). The study is based on a recent literature review and on the experience of our tertiary referral center. Data were retrospectively analyzed from the electronic medical records of 235 patients (461 eyes) suffering from a biopsy-proven ocular sarcoidosis. Middle-aged females presenting bilateral ocular involvement are mainly affected; eye involvement at onset is present in one-third of subjects. Uveitis subtype presentation ranges widely among different studies: panuveitis and multiple chorioretinal granulomas, retinal segmental vasculitis, intermediate uveitis and vitreitis, anterior uveitis with granulomatous mutton-fat keratic precipitates, iris nodules, and synechiae are the main ocular features. The most important complications are cataract, glaucoma, cystoid macular edema (CME), and epiretinal membrane. Therapy is based on the disease localization and the severity of systemic or ocular involvement. Local, intravitreal, or systemic steroids are the mainstay of treatment; refractory or partially responsive disease has to be treated with conventional and biologic immunosuppressants. In conclusion, we summarize the current knowledge and assessment of ophthalmological inflammatory manifestations (mainly uveitis) of OS, which permit an early diagnostic assay and a prompt treatment.

Novel HLA associations with outcomes of Mycobacterium tuberculosis exposure and sarcoidosis in individuals of African ancestry using nearest-neighbor feature selection

Tuberculosis and sarcoidosis are inflammatory diseases characterized by granulomas that may occur in any organ but are often found in the lung. The panoply of classical human leukocyte antigen (HLA) alleles associated with occurrence and/or severity of both diseases varies considerably across studies. This heterogeneity of results, due to variation in factors like ancestry and disease subphenotype, as well as the use of simple modeling strategies to elucidate likely complex relationships, has made conclusions about underlying commonalities difficult. Here we perform HLA association analyses in individuals of African ancestry, using a greater resolution to include subphenotypes of disease and employing more comprehensive analytical techniques. Using a novel application of nearest-neighbor feature selection to score allelic importance, we investigated HLA allele association with Mycobacterium tuberculosis exposure outcomes in the first analysis of both latent Mycobacterium tuberculosis infection and active disease compared with those who, despite long-term exposure to active index cases, have neither positive diagnostic tests nor display clinical symptoms. We also compared persistent to resolved sarcoidosis. This led to the identification of novel HLA associations and evidence of main effects and interaction effects. We found strikingly similar main effects and interaction effects at HLA-DRB1, -DQB1, and -DPB1 in those resistant to tuberculosis (either latent or active) and persistent sarcoidosis.

HLA class II variants defined by next generation sequencing are associated with sarcoidosis in Korean patients

Polymorphic genes with immune functions, namely those of the human leukocyte antigen (HLA) system, have been implicated in sarcoidosis pathogenesis. As HLA polymorphisms in sarcoidosis have not been yet investigated in the Korean population, we used next-generation sequencing (NGS), allowing detailed characterization of HLA alleles to investigate the role of HLA variation in Korean sarcoidosis patients. We enrolled 103 patients diagnosed by the ATS/ERS/WASOG guidelines at Asan Medical Centre, Seoul, Korea. Among those, genotyping of 7 HLA loci (HLA-A, -B, -C, -DQA1, -DQB1, -DRB1, -DPB1) was performed using Omixon Holotype™ kit and HLATwin software™. HLA allele frequencies were compared with frequency data on healthy Koreans from the allelic frequency databases, and 4-digit characteristics of HLA genotyping were used. Associations were assessed by two-tailed Fischer’s exact test with correction for multiple comparisons. Variants previously associated with sarcoidosis risk (HLA-C*03:04, HLA-DRB1*12:01, HLA-DRB1*14:54) and a known protective variant HLA-DPB1*04:01, were associated with sarcoidosis in Koreans. Further, we suggest new HLA variants associated with sarcoidosis risk (e.g., HLA-DQA1*05:08) and novel protective variants HLA-DQB1*03:02 and HLA-DQA1*01:02 in Koreans. This first study of HLA variation in Korean patients with sarcoidosis by precise genotyping methodology reports data that could serve future meta-analyses on HLA variation’s role in sarcoidosis.

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.

Innate and Adaptive Immunity in Noninfectious Granulomatous Lung Disease

Sarcoidosis and chronic beryllium disease are noninfectious lung diseases that are characterized by the presence of noncaseating granulomatous inflammation. Chronic beryllium disease is caused by occupational exposure to beryllium containing particles, whereas the etiology of sarcoidosis is not known. Genetic susceptibility for both diseases is associated with particular MHC class II alleles, and CD4⁺ T cells are implicated in their pathogenesis. The innate immune system plays a critical role in the initiation of pathogenic CD4⁺ T cell responses as well as the transition to active lung disease and disease progression. In this review, we highlight recent insights into Ag recognition in chronic beryllium disease and sarcoidosis. In addition, we discuss the current understanding of the dynamic interactions between the innate and adaptive immune systems and their impact on disease pathogenesis.

Progress in the genetics of uveitis

Uveitis is the most common form of intraocular inflammatory disease and is a significant cause of visual impairment worldwide. Aetiologically, uveitis can also be classified into infectious uveitis and non-infectious uveitis. The common non-infectious forms of uveitis include acute anterior uveitis (AAU), Behçet’s disease (BD), Vogt-Koyanagi-Harada (VKH) disease, birdshot chorioretinopathy (BSCR), sarcoid uveitis. In addition, a few monogenic autoinflammatory disorders can also cause uveitis, such as Blau Syndrome and haploinsufficiency of A20 (HA20). Although the exact pathogenesis of non-infectious uveitis is still unclear, it is well-recognised that it involves both genetic and environmental risk factors. A hallmark of uveitis is its strong associations with human leucocyte antigens (HLA). For examples, AAU, BD and BSCR are strongly associated with HLA-B27, HLA-B51, and HLA-A29, respectively. In uveitis studies, multiple GWAS have successfully been conducted and led to identification of novel susceptibility loci, for example, IL23R has been identified in BD, VKH and AAU. In this review, we summarize the latest progress on the genetic associations of both HLA and non-HLA genes with major forms of uveitis, including AAU, BD, VKH, BSCR, sarcoid uveitis, Blau Syndrome and HA20, and potential future research directions.

Germline HLA landscape does not predict efficacy of pembrolizumab monotherapy across solid tumor types

We evaluated the impact of class I and class II human leukocyte antigen (HLA) genotypes, heterozygosity, and diversity on the efficacy of pembrolizumab. Seventeen pembrolizumab clinical trials across eight tumor types and one basket trial in patients with advanced solid tumors were included (n > 3,500 analyzed). Germline DNA was genotyped using a custom genotyping array. HLA diversity (measured by heterozygosity and evolutionary divergence) across class I loci was not associated with improved response to pembrolizumab, either within each tumor type evaluated or across all patients. Similarly, HLA heterozygosity at each class I and class II gene was not associated with response to pembrolizumab after accounting for the number of tests conducted. No conclusive association between HLA genotype and response to pembrolizumab was identified in this dataset. Germline HLA genotype or diversity alone is not an important independent determinant of response to pembrolizumab and should not be used for clinical decision-making in patients treated with pembrolizumab.

Sarcoidosis Following Hematopoietic Stem Cell Transplantation: Clinical Characteristics and HLA Associations

Purpose

Extrinsic factors and genetic predisposition contribute to the etiology of sarcoidosis, converging in a phenotype of altered immune response associated with multisystemic inflammatory granulomatous tissue infiltration. Immunological reconstitution after hematopoietic stem cell transplantation (HSCT) may represent a unique window for the pathogenesis of the disease. We describe the incidence, clinicopathological features, and HLA associations of sarcoidosis after HSCT in a single-center cohort of patients, together with data from previously published cases.

Methods

We retrospectively analyzed clinical characteristics and HLA haplotypes from allogeneic (allo) or autologous (auto) HSCT patients from January 2001 through May 2021 at the University Medicine Goettingen (UMG), and data from previously published cases.

Results

A total number of 19 patients was identified. These included 4 patients from our center (3 allo HSCT and 1 auto HSCT) and 15 patients from the literature review. Thirteen patients had received an allo HSCT, and six patients had received an auto HSCT. Sarcoidosis occurred after a median interval of 20 (after allo HSCT) and 7 (after auto HSCT) months, respectively. The predominant HLA allele associated with sarcoidosis was HLA DRB1*03:01. Sarcoidosis involved the respiratory tract in 15 patients (three unknown, one without pulmonary involvement), and it was associated with graft-versus-host disease in 7 of 13 patients receiving allo HSCT. None of the donors or patients had a history of sarcoidosis before transplantation. Disease manifestations resolved with standard glucocorticoid treatment without long-term sequelae.

Conclusion

Sarcoidosis may occur at low frequency during reconstitution of the immune system after HSCT. HLA allele associations reflect the associations observed in the general population, particularly with DRB1*03:01. Further insights into the interplay between Tcell reconstitution and the development of sarcoidosis could also provide novel approaches to an improved understanding of the pathogenesis in sarcoidosis.

HLA-DRB1 alleles associate with hypercalcemia in sarcoidosis

BACKGROUND

The mechanisms behind and which patients are at risk of developing sarcoidosis associated hypercalcemia (SAHC) have not been addressed. Different human leukocyte antigen (HLA) alleles associate with disease phenotypes in sarcoidosis. Insights into associations between HLA alleles, clinical phenotype and calcium levels may provide clues to mechanisms behind SAHC and help monitoring patients at risk for SAHC.

AIMS AND OBJECTIVES

To identify any HLA-association with SAHC, and to phenotypically characterize this patient group.

METHODS

66 patients with SAHC (s-Ca²⁺>1.33 mmol/L) and 150 normocalcemic patients as controls were identified in a cohort of sarcoidosis patients. Data on HLA-DRB1 alleles, sex, angiotensin-converting enzyme (ACE), creatinine, extrapulmonary manifestations (EPM), age at sarcoidosis diagnosis, and how long after diagnosis SAHC emerged, were retrieved.

RESULTS

HLA-DRB1*04 was more common in patients with SAHC and the proportion of patients with HLA-DRB1*04 increased the more pronounced hypercalcemia. In patients with s-Ca²⁺>1.4 mmol/L, 20 out of 30 carried the HLA-DRB1*04 allele (67%, p < 0.01). Patients with SAHC more often disclosed renal insufficiency, elevated ACE, EPM, and a non-resolving disease than controls. The mean duration between sarcoidosis diagnosis and detection of SAHC was 1.39 years.

CONCLUSIONS

SAHC is associated with a more severe disease phenotype, particularly patients carrying the HLA-DRB1*04 allele are at higher risk for SAHC. HLA-assessment in the clinic can be a way to identify these patients. The results provide a basis for future studies on the connection between HLA-DRB1*04 and SAHC mechanisms.

Epigenetics and sarcoidosis

Epigenetic modifications are emerging as important regulatory mechanisms of gene expression in lung disease, given that they are influenced by environmental exposures and genetic variants, and that they regulate immune and fibrotic processes. In this review, we introduce these concepts with a focus on the study of DNA methylation and histone modifications and discuss how they have been applied to lung disease, and how they can be applied to sarcoidosis. This information has implications for other exposure and immunologically mediated lung diseases, such as chronic beryllium disease, hypersensitivity pneumonitis, and asbestosis.

A Primer on the Clinical Aspects of Sarcoidosis for the Basic and Translational Scientist

The immunopathogenesis of sarcoidosis remains unclear. This failure in understanding has been clinically impactful, as it has impeded the accurate diagnosis, treatment, and prevention of this disease. Unraveling the mechanisms of sarcoidosis will require input from basic and translational scientists. In order to reach this goal, scientists must have a firm grasp of the clinical aspects of the disease, including its diagnostic criteria, the immunologic defects, clinical presentations, response to therapy, risk factors, and clinical course. This manuscript will provide an overview of the clinical aspects of sarcoidosis that are particularly relevant for the basic and translational scientist. The variable phenotypic expression of the disease will be described, which may be integral in identifying immunologic disease mechanisms that may be relevant to subgroups of sarcoidosis patients. Data concerning treatment and risk factors may yield important insights concerning germane immunologic pathways involved in the development of disease. It is hoped that this manuscript will stimulate communication between scientists and clinicians that will eventually lead to improved care of sarcoidosis patients.

Sarcoidosis: An Occupational Disease?

Sarcoidosis is an important member of the family of granulomatous lung diseases. Since its recognition in the late 19th century, sarcoidosis has been thought of as a disease of unknown cause. Over the past 20 years, this paradigm has been shifting, more rapidly in the past 10 years. Epidemiologic studies, bolstered by case reports, have provided evidence of causal associations between occupational exposure to specific agents and sarcoidosis. Pathogenesis has been more clearly defined, including the role of gene-exposure interactions. The use of in vitro lymphocyte proliferation testing to detect sensitization to inorganic antigens is being examined in patients with sarcoidosis. These antigens include silica and certain metals. Results of studies to date show differences in immunoreactivity of occupationally exposed sarcoidosis cases compared with control cases, suggesting that lymphocyte proliferation testing may prove useful in diagnosing work-related disease. This review discusses recently published findings regarding associations between occupational exposure to silica and silicates, World Trade Center dust, and metals and risk for sarcoidosis, as well as advances in the development of diagnostic tools. Not all cases of sarcoidosis have an identified cause, but some do. Where the cause is occupational, its recognition is critical to enable effective treatment through removal of the affected worker from exposure and to inform intervention aimed at primary prevention.

Pathogenesis of Non-Infectious Uveitis Elucidated by Recent Genetic Findings

Uveitis is a generic term for inflammation of the uvea, which includes the iris, ciliary body, and choroid. Prevalence of underlying non-infectious uveitis varies by race and region and is a major cause of legal blindness in developed countries. Although the etiology remains unclear, the involvement of both genetic and environmental factors is considered important for the onset of many forms of non-infectious uveitis. Major histocompatibility complex (MHC) genes, which play a major role in human immune response, have been reported to be strongly associated as genetic risk factors in several forms of non-infectious uveitis. Behçet’s disease, acute anterior uveitis (AAU), and chorioretinopathy are strongly correlated with MHC class I-specific alleles. Moreover, sarcoidosis and Vogt-Koyanagi-Harada (VKH) disease are associated with MHC class II-specific alleles. These correlations can help immunogenetically classify the immune pathway involved in each form of non-infectious uveitis. Genetic studies, including recent genome-wide association studies, have identified several susceptibility genes apart from those in the MHC region. These genetic findings help define the common or specific pathogenesis of ocular inflammatory diseases by comparing the susceptibility genes of each form of non-infectious uveitis. Interestingly, genome-wide association of the interleukin (IL)23R region has been identified in many of the major forms of non-infectious uveitis, such as Behçet’s disease, ocular sarcoidosis, VKH disease, and AAU. The interleukin-23 (IL-23) receptor, encoded by IL23R, is expressed on the cell surface of Th17 cells. IL-23 is involved in the homeostasis of Th17 cells and the production of IL-17, which is an inflammatory cytokine, indicating that a Th17 immune response is a common key in the pathogenesis of non-infectious uveitis. Based on the findings from the immunogenetics of non-infectious uveitis, a personalized treatment approach based on the patient’s genetic make-up is expected.

Genome-Wide Association Study of Ocular Sarcoidosis Confirms HLA Associations and Implicates Barrier Function and Autoimmunity in African Americans

Purpose: Identify genes associated with ocular sarcoidosis (OS).Methods: We genotyped 1.1 million genetic variants to identify significant OS associations, defined as those that achieved p < 5 × 10-8 in a genome-wide comparison of OS cases to healthy controls in our European- or African-American cohorts (EA, AA). Potential functional roles of all associated variants were assessed.Results: Eight significant non-HLA variants were found in AA OS cases compared to healthy controls and confirmed as at least suggestive when comparing OS to non-OS cases. Seven of these were within MAGI1 and include transcription factor binding sites and expression quantitative trait loci. Our EA cohort, while showing similar effect sizes at variants within MAGI1, had no significant variants. Association analysis of HLA-DRB1 alleles confirmed association to OS in EA to *04:01.Conclusion: Our results support organ-specific genetic risk in OS in a compelling candidate, MAGI1, known to be associated with barrier function and autoimmunity.

Novel three-dimensional biochip pulmonary sarcoidosis model

Sarcoidosis is a multi-system disorder of granulomatous inflammation which most commonly affects the lungs. Its etiology and pathogenesis are not well defined in part due to the lack of reliable modeling. Here, we present the development of an in vitro three-dimensional lung-on-chip biochip designed to mimic granuloma formation. A lung on chip fluidic macrodevice was developed and added to our previously developed a lung-on-membrane model (LOMM). Granulomas were cultured from blood samples of patients with sarcoidosis and then inserted in the air-lung-interface of the microchip to create a three-dimensional biochip pulmonary sarcoidosis model (3D BSGM). Cytokines were measured after 48 hours. ELISA testing was performed to measure cytokine response difference between LOMM with 3D BSGM. There were statistically significant differences in IL-1ß (P = 0.001953), IL-6 (P = 0.001953), GM-CSF (P = 0.001953), and INF-γ expressions (P = 0.09375) between two groups. The current model represents the first 3D biochip sarcoidosis model created by adding a microfluidics system to a dual-chambered lung on membrane model and introducing developed sarcoid-granuloma to its air-lung-interface.

DNA sequencing validation by PCR-RFLP for evaluating butyrophilin-like 2 rs2076530 polymorphism in Iranian patients with sarcoidosis

BACKGROUND

Sarcoidosis is a multifactorial immune disorder with an uncertain origin. A single nucleotide polymorphism (G→A, rs2076530) in the butyrophilin-like 2 (BTNL2) gene results in the formation of truncating protein. This study aimed to genotype the predisposition of the BTNL2 rs2076530 polymorphism in Iranian patients with sarcoidosis using the RFLP technique.

MATERIALS AND METHODS

In this study, 80 patients with sarcoidosis and 80 healthy individuals were included. The rs2076530 polymorphism of the BTNL2 gene was genotyped using the PCR-RFLP method by AvrII restriction enzyme and confirmed by DNA sequencing (Capillary electrophoresis 3130, ABI).

RESULTS

There was a statistically significant difference between proportions of patients with AA (47,5%) and controls (27.5%) (OR=2.38, 95%CI:1.23-4.61, P=0.009). In addition, a significant difference was observed in the frequency of the A allele (62.5%) in sarcoidosis (OR=2.14, 95%CI:1.37-3.35, P=0.001). A Bonferroni correction with P<0.0038 indicates a statistical difference for genotype AA (P=0.009). In an effective model, binary logistic regression analysis indicates a statistical association between AA genotype and sarcoidosis (P=0.018 with 60% prediction). Based on the gene analysis study using DNA sequencing, all of the mentioned mutations were seen via RFLP.

CONCLUSION

According to our findings, the BTNL2 rs2076530 A allele in the Iranian population is associated with susceptibility to sarcoidosis. This designed PCR-RFLP method for detecting SNPs is effective as DNA sequencing.

Treatment of Sarcoidosis: A Multidisciplinary Approach

Sarcoidosis is a systemic disease of unknown etiology defined by the presence of noncaseating granulomatous inflammation that can cause organ damage and diminished quality of life. Treatment is indicated to protect organ function and decrease symptomatic burden. Current treatment options focus on interruption of granuloma formation and propagation. Clinical trials guiding evidence for treatment are lacking due to the rarity of disease, heterogeneous clinical course, and lack of prognostic biomarkers, all of which contribute to difficulty in clinical trial design and implementation. In this review, a multidisciplinary treatment approach is summarized, addressing immunuosuppressive drugs, managing complications of chronic granulomatous inflammation, and assessing treatment toxicity. Discovery of new therapies will depend on research into pathogenesis of antigen presentation and granulomatous inflammation. Future treatment approaches may also include personalized decisions based on pharmacogenomics and sarcoidosis phenotype, as well as patient-centered approaches to manage immunosuppression, symptom control, and treatment of comorbid conditions.

Current Insights in Genetics of Sarcoidosis: Functional and Clinical Impacts

Sarcoidosis is a complex disease that belongs to the vast group of autoinflammatory disorders, but the etiological mechanisms of which are not known. At the crosstalk of environmental, infectious, and genetic factors, sarcoidosis is a multifactorial disease that requires a multidisciplinary approach for which genetic research, in particular, next generation sequencing (NGS) tools, has made it possible to identify new pathways and propose mechanistic hypotheses. Codified treatments for the disease cannot always respond to the most progressive forms and the identification of new genetic and metabolic tracks is a challenge for the future management of the most severe patients. Here, we review the current knowledge regarding the genes identified by both genome wide association studies (GWAS) and whole exome sequencing (WES), as well the connection of these pathways with the current research on sarcoidosis immune-related disorders.

The opposite effect of human leukocyte antigen genotypes in sarcoidosis and tuberculosis: a narrative review of the literature

Sarcoidosis and tuberculosis share several similar clinical and pathogenic characteristics that make some researchers consider a common pathogenesis for these diseases. Human leukocyte antigen (HLA) genotypes are studied both in sarcoidosis and tuberculosis patients, but to our knowledge, there are no comparative studies of genetic predisposition for sarcoidosis and tuberculosis development.

The aim of this review was to analyse the relationship between HLA genotypes and the development of sarcoidosis and tuberculosis. Original and review articles published in various online databases from 1960 to 2019 were studied.

The search results showed opposite effects of the HLA genotypes on predisposition to sarcoidosis or tuberculosis. It was revealed that the genotypes predisposing to the development of sarcoidosis (HLA-DRB1*03/07/15) have protective properties against the development of tuberculosis. Moreover, genotypes causing the development of tuberculosis (HLA-DRB1*04) have a protective effect on the development of sarcoidosis.

The results of this narrative review of the literature may allude to the existence of genetic predispositions that lead to the development of an antibacterial or autoimmune response to mycobacteria.

The HLA-DRB1*03/07/15 genotypes predispose to the development of sarcoidosis and have protective properties against the development of tuberculosis, while the HLA-DRB1*04 genotype has an opposite effect on the development of these diseaseshttps://bit.ly/2Tl2rj1

Ocular Sarcoidosis

Sarcoidosis is one of the leading causes of inflammatory eye disease. Any part of the eye and its adnexal tissues can be involved. Uveitis and optic neuropathy are the main manifestations, which may require systemic treatment. Two groups of patients with sarcoid uveitis can be distinguished: one of either sex and any ethnicity in which ophthalmological findings are various and another group of elderly Caucasian women with mostly chronic posterior uveitis. Clinically isolated uveitis revealing sarcoidosis remains a strictly ocular condition in a large majority of cases. Although it can be a serious condition involving functional prognosis, early recognition in addition to a growing therapeutic arsenal (including intravitreal implant) has improved the visual prognosis of the disease in recent years. Systemic corticosteroids are indicated when uveitis does not respond to topical corticosteroids or when there is bilateral posterior involvement, especially macular edema. In up to 30% of the cases that require an unacceptable dosage of corticosteroids to maintain remission, additional immunosuppression is used, especially methotrexate. As with other forms of severe noninfectious uveitis, monoclonal antibodies against tumor necrosis factor-α have been used. However, only very rarely does sarcoid uveitis fail to respond to combined corticosteroids and methotrexate therapy, a situation that should suggest either poor adherence or another granulomatous disease. Optic neuropathy often affects women of African and Caribbean origins. Some authors recommend that patients should be treated with high-dose of corticosteroids and concurrent immunosuppression from the onset of this manifestation, which is associated with a poorer outcome.

Large-scale genome-wide association study identifies HLA class II variants associated with chronic HBV infection: a study from Taiwan Biobank

BACKGROUND

Chronic hepatitis B virus (HBV) infection is a great health burden with geographical variations.

AIMS

To explore genetic variants associated with chronic HBV infection.

METHODS

The study included 15 352 participants seropositive for HBV core antibodies in Taiwan Biobank. Among them, 2591 (16.9%) seropositive for HBV surface antigen (HBsAg) were defined as having chronic HBV infection. All participants were examined for whole-genome genotyping by Axiom-Taiwan Biobank Array. The human leucocyte antigen (HLA) imputation was performed after identification of the variants within the region. Logistic regressions were used to estimate odds ratios (ORs) with 95% confidence intervals. Correlations of different HLA allele frequencies with HBsAg seroprevalence were evaluated across worldwide populations by Pearson correlation coefficients. Epitope prediction was performed for HLA alleles using NetMHCIIpan method.

RESULTS

Located within a cluster of 450 single nucleotide polymorphisms in HLA class II, rs7770370 (P = 2.73 × 10^-35 ) was significantly associated with HBV chronicity (P_corrected  < 8.6 × 10^-8 ). Imputation analyses showed that HLA-DPA1*02:02 and HLA-DPB1*05:01 were associated with chronic HBV, with adjusted ORs of 1.43 (1.09-1.89) and 1.61 (1.29-2.01). These allele frequencies were positively correlated with global HBsAg seroprevalence, with R of 0.75 and 0.62 respectively (P < 0.05). HLA-DRB1*13:02, HLA-DQA1* 01:02 and HLA-DQB1*06:09 associated with HBV chronicity negatively, with adjusted ORs of 0.31 (0.17-0.58), 0.70 (0.56-0.87) and 0.33 (0.18-0.63). These HLA alleles had various binding affinities to the predicted epitopes derived from HBV nucleocapsid protein.

CONCLUSIONS

HLA class II variants are relevant for chronicity after HBV acquisition.

Environmental Risk Factors for Sarcoidosis

Sarcoidosis is a multisystem granulomatous disease that may affect any body organ. Sarcoidosis is associated with many environmental and occupational exposures. Because the exact immunopathogenesis of sarcoidosis is unknown, it is not known whether these exposures are truly causing sarcoidosis, rendering the immune system more susceptible to the development of sarcoidosis, exacerbating subclinical cases of sarcoidosis, or causing a granulomatous condition distinct from sarcoidosis. This manuscript outlines what is known about the immunopathogenesis of sarcoidosis and postulates mechanisms whereby these exposures could cause or exacerbate the disease. We also describe the varied environmental and occupational exposures that have been associated with sarcoidosis. This includes potential infectious exposures such as mycobacteria and Propionibacterium acnes, a skin commensal bacterium, as well as non-infectious environmental exposures including inhaled bioaerosols, metal dusts and products of combustion. Further insights concerning the relationship of environmental exposures to the development of sarcoidosis may have a major impact on the prevention and treatment of this enigmatic disease.

Activation of the interleukin-23/interleukin-17 signalling pathway in autoinflammatory and autoimmune uveitis

Uveitis is a group of diseases characterized by intraocular inflammation, of which some are driven by autoinflammatory or autoimmune responses, such as Vogt-Koyanagi-Harada disease, Behçet's disease, uveitis associated with spondyloarthritis, ocular sarcoidosis, sympathetic ophthalmia and birdshot chorioretinopathy. These entities have various clinical forms, but genetic and biomarker data suggest that they share a common molecular basis, activation of the Interleukin (IL)-23/IL-17 pathway. Multiple factors including genetic predisposition, various cytokine imbalances, infectious agents and gut alterations are found to trigger an aberrant response of this pathway. The enhanced activity of the IL-23/IL-17 pathway is committed to the expansion and pathogenicity of Th17 cells. Evidence from animal models demonstrates that the development of pathogenic Th17 cells is responsible for the induction of experimental autoimmune uveitis. Further findings indicate that retinal pigment epithelium (RPE) cells may be a target of IL-17. IL-17 triggers downstream inflammatory cascades and causes dysfunction of RPE cells, which may affect retinal barrier function and thereby promote intraocular inflammation. Currently, several emerging drugs blocking the IL-23/IL-17 pathway have been assessed for the treatment of uveitis in pilot studies. The purpose of this is to summarize updated biological knowledge and preliminary clinical data, providing the rationale for further development and evaluation of novel drugs targeting the IL-23/IL-17 pathway in autoinflammatory and autoimmune uveitis. Future studies may focus on translational medicine targeting the IL-23/IL-17 pathway for the improvement of diagnosis and treatment of uveitis. In conclusion, activation of the IL-23/IL-17 pathway is a critical biological event and can be an important target for the treatment of autoinflammatory and autoimmune uveitis.

Genetic contributions to the etiology of anorexia nervosa: New perspectives in molecular diagnosis and treatment

Background

Anorexia nervosa is a multifactorial eating disorder that manifests with self‐starvation, extreme anxiety, hyperactivity, and amenorrhea. Long‐term effects include organ failure, disability, and in extreme cases, even death.

Methods

Through a literature search, here we summarize what is known about the molecular etiology of anorexia nervosa and propose genetic testing for this condition.

Results

Anorexia nervosa often has a familial background and shows strong heritability. Various genetic studies along with genome‐wide association studies have identified several genetic loci involved in molecular pathways that might lead to anorexia.

Conclusion

Anorexia nervosa is an eating disorder with a strong genetic component that contributes to its etiology. Various genetic approaches might help in the molecular diagnosis of this disease and in devising novel therapeutic options.

Anorexia nervosa is a multifactorial eating disorder with a strong genetic component that manifests with self‐starvation, extreme anxiety, hyperactivity, and amenorrhea. Through a literature search, here we summarize what is known about the molecular etiology of anorexia nervosa and propose genetic testing for this condition.

Adaptive Immunity in Pulmonary Sarcoidosis and Chronic Beryllium Disease

Pulmonary sarcoidosis and chronic beryllium disease (CBD) are inflammatory granulomatous lung diseases defined by the presence of non-caseating granulomas in the lung. CBD results from beryllium exposure in the workplace, while the cause of sarcoidosis remains unknown. CBD and sarcoidosis are both immune-mediated diseases that involve Th1-polarized inflammation in the lung. Beryllium exposure induces trafficking of dendritic cells to the lung in a mechanism dependent on MyD88 and IL-1α. B cells are also recruited to the lung in a MyD88 dependent manner after beryllium exposure in order to protect the lung from beryllium-induced injury. Similar to most immune-mediated diseases, disease susceptibility in CBD and sarcoidosis is driven by the expression of certain MHCII molecules, primarily HLA-DPB1 in CBD and several HLA-DRB1 alleles in sarcoidosis. One of the defining features of both CBD and sarcoidosis is an infiltration of activated CD4+ T cells in the lung. CD4+ T cells in the bronchoalveolar lavage (BAL) of CBD and sarcoidosis patients are highly Th1 polarized, and there is a significant increase in inflammatory Th1 cytokines present in the BAL fluid. In sarcoidosis, there is also a significant population of Th17 cells in the lungs that is not present in CBD. Due to persistent antigen exposure and chronic inflammation in the lung, these activated CD4+ T cells often display either an exhausted or anergic phenotype. Evidence suggests that these T cells are responding to common antigens in the lung. In CBD there is an expansion of beryllium-responsive TRBV5.1+ TCRs expressed on pathogenic CD4+ T cells derived from the BAL of CBD patients that react with endogenous human peptides derived from the plexin A protein. In an acute form of sarcoidosis, there are expansions of specific TRAV12-1/TRBV2 T cell receptors expressed on BAL CD4+ T cells, indicating that these T cells are trafficking to and expanding in the lung in response to common antigens. The specificity of these pathogenic CD4+T cells in sarcoidosis are currently unknown.

Proceedings of the 2015 AASOG conference: Reducing disparities in sarcoidosis through personalized care and increased detection

The 2015 annual meeting of the Americas Association of Sarcoidosis and Other Granulomatous Disorders (AASOG) was held on September 25th and 26th at the University of Colorado Anschutz Medical Campus in Aurora, CO, U.S.A. The meeting was hosted by National Jewish Health and the theme of the meeting was "Reducing Disparities in Sarcoidosis through Personalized Care and Increased Detection". The meeting was endorsed by the American Thoracic Society (ATS) and the Foundation for Sarcoidosis Research (FSR), and was conducted through support provided by the National Institutes of Health (NIH), particularly the National Heart Lung and Blood Institute (NHLBI), and an unrestricted educational grant from Mallinckrodt, Inc. The meeting participants were predominantly from North America, and included preeminent experts and emerging clinical scientists engaged in sarcoidosis research. The AASOG meeting was held in parallel with a sarcoidosis patient conference that was organized and funded by the Foundation of Sarcoidosis Research (FSR). The AASOG talks covered various state-of-the-arts topics related to sarcoidosis research and care; most notable were talks focusing on preliminary and emerging data from the Genomic Research in Alpha-1 antitrypsin Deficiency and Sarcoidosis (GRADS) study, recent novel immunological and genomic discoveries that further our understanding of sarcoidosis disease pathogenesis, results from clinical trials in sarcoidosis and proposals of novel therapeutic targets for the treatment of sarcoidosis, the introduction of the FSR sponsored clinical studies network, insights from other granulomatous diseases, and a focus on extra-pulmonary sarcoidosis, particularly cardiac disease, small fiber neuropathy, and fatigue. A session dedicated to scientific abstracts from predominantly junior investigators and five oral abstract presentations brought the conference to a conclusion. A brief overview and selected excerpts of the 2015 AASOG meeting proceedings are provided herein. (Sarcoidosis Vasc Diffuse Lung Dis 2017; 34: 264-268).