Human leukocyte antigen-DR alleles influence the clinical course of pulmonary sarcoidosis in Asian Indians

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.

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.

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.

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

Genetic, Immunologic, and Environmental Basis of Sarcoidosis

Sarcoidosis is a multisystem disease with tremendous heterogeneity in disease manifestations, severity, and clinical course that varies among different ethnic and racial groups. To better understand this disease and to improve the outcomes of patients, a National Heart, Lung, and Blood Institute workshop was convened to assess the current state of knowledge, gaps, and research needs across the clinical, genetic, environmental, and immunologic arenas. We also explored to what extent the interplay of the genetic, environmental, and immunologic factors could explain the different phenotypes and outcomes of patients with sarcoidosis, including the chronic phenotypes that have the greatest healthcare burden. The potential use of current genetic, epigenetic, and immunologic tools along with study approaches that integrate environmental exposures and precise clinical phenotyping were also explored. Finally, we made expert panel-based consensus recommendations for research approaches and priorities to improve our understanding of the effect of these factors on the health outcomes in sarcoidosis.

Bioinformatics analysis of gene expression profile data to screen key genes involved in pulmonary sarcoidosis

BACKGROUND

Sarcoidosis is a multisystemic inflammatory and granulomatous disease that occurs in almost all populations and affects multiple organs. Meanwhile, its most common manifestation is pulmonary sarcoidosis. This study aimed to identify effective biomarkers for the diagnosis and therapy of pulmonary sarcoidosis.

METHODS

GSE16538 was downloaded from Gene Expression Omnibus, including 6 pulmonary sarcoidosis samples and 6 normal lung samples. Then, differentially expressed genes (DEGs) were identified by limma package in R. After the expression values of the DEGs were extracted, hierarchical clustering analysis was performed for the DEGs using the pheatmap package in R. Subsequently, protein-protein interaction (PPI) pairs among the DEGs were searched by STRING or REACTOME databases, and then PPI networks were visualized by Cytoscape software. Using DAVID and KOBAS, functional and pathway enrichment analyses separately were performed for the DEGs involved in the PPI network.

RESULTS

Total 208 DEGs were identified in pulmonary sarcoidosis samples, including 179 up-regulated genes and 29 down-regulated genes. Hierarchical clustering showed that the DEGs could clearly distinguish the pulmonary sarcoidosis samples from the normal lung samples. In the PPI network constructed by STRING database, CXCL9, STAT1, CCL5, CXCL11 and GBP1 had higher degrees and betweenness values, and could interact with each other. Functional enrichment showed that CXCL9, CXCL11 and CCL5 were enriched in immune response. Moreover, STAT1 was enriched in pathways of chemokine signaling pathway and JAK-STAT signaling pathway.

CONCLUSION

CXCL9, CXCL11, STAT1, CCL5 and GBP1 might be implicated in pulmonary sarcoidosis through interacting with each other.

Immunogenetics of Disease-Causing Inflammation in Sarcoidosis

Sarcoidosis is a systemic inflammatory disorder characterised by tissue infiltration by mononuclear phagocytes and lymphocytes with associated non-caseating granuloma formation. Originally described as a disorder of the skin, sarcoidosis can involve any organ with wide-ranging clinical manifestations and disease course. Recent studies have provided new insights into the mechanisms involved in disease pathobiology, and we now know that sarcoidosis has a clear genetic basis largely involving human leukocyte antigen (HLA) genes. In contrast to Mendelian-monogenic disorders--which are generally due to specific and relatively rare mutations often leading to a single amino acid change in an encoded protein--sarcoidosis results from genetic variations relatively common in the general population and involving multiple genes, each contributing an effect of varying magnitude. However, an individual may have the necessary genetic profile and yet the disease will not develop unless an environmental or infectious factor is encountered. Genetics appears also to contribute to the huge variability in clinical phenotype and disease behaviour. Moreover, it has been established that sarcoidosis granulomatous inflammation is a highly polarized T helper 1 immune response that starts with an antigenic stimulus followed by T cell activation via a classic HLA class II-mediated pathway. A complex network of lymphocytes, macrophages, and cytokines is pivotal in the orchestration and evolution of the granulomatous process. Despite these advances, the aetiology of sarcoidosis remains elusive and its pathogenesis incompletely understood. As such, there is an urgent need for a better understanding of disease pathogenesis, which hopefully will translate into the development of truly effective therapies.

Etiologies of Sarcoidosis

Since sarcoidosis was first described more than a century ago, the etiologic determinants causing this disease remain uncertain. Studies suggest that genetic, host immunologic, and environmental factors interact together to cause sarcoidosis. Immunologic characteristics of sarcoidosis include non-caseating granulomas, enhanced local expression of T helper-1 (and often Th17) cytokines and chemokines, dysfunctional regulatory T-cell responses, dysregulated Toll-like receptor signaling, and oligoclonal expansion of CD4+ T cells consistent with chronic antigenic stimulation. Multiple environmental agents have been suggested to cause sarcoidosis. Studies from several groups implicate mycobacterial or propionibacterial organisms in the etiology of sarcoidosis based on tissue analyses and immunologic responses in sarcoidosis patients. Despite these studies, there is no consensus on the nature of a microbial pathogenesis of sarcoidosis. Some groups postulate sarcoidosis is caused by an active viable replicating infection while other groups contend there is no clinical, pathologic, or microbiologic evidence for such a pathogenic mechanism. The authors posit a novel hypothesis that proposes that sarcoidosis is triggered by a hyperimmune Th1 response to pathogenic microbial and tissue antigens associated with the aberrant aggregation of serum amyloid A within granulomas, which promotes progressive chronic granulomatous inflammation in the absence of ongoing infection.

Granuloma genes in sarcoidosis: what is new?

PURPOSE OF REVIEW

Nonnecrotizing granulomas in the affected organ are the hallmark of sarcoidosis. This review summarizes most recent genetic findings in sarcoidosis with a focus on genes that might influence granuloma formation or resolution. Specific results in multiple ethnic groups and certain clinical subphenotypes, such as extra-pulmonary organ involvement, are discussed.

RECENT FINDINGS

Associations of genetic variants in antigen-presenting molecules (HLA-DRB1) were shown to confer risk to sarcoidosis and certain disease phenotypes in populations of different ethnic origins. Specific DRB1 alleles, such as *0301 and *0302, appear to confer protection against chronic disease, but in an ethnic-specific manner illustrating the extensive genetic heterogeneity and complexity at this locus. Mechanistic studies of putative sarcoid antigens lend further credence to a role of HLA-DRB1 in disease pathogenesis. With relevance to granuloma formation, genes involved in apoptotic processes and immune cell activation were further confirmed (ANXA11 and BTNL2) in multiple ethnicities; others were newly identified (XAF1). Linking mechanism to clinical application, a TNF variant was shown to correlate with anti-TNF response in sarcoidosis patients.

SUMMARY

The investigation of known and novel risk variants for sarcoidosis and specific clinical phenotypes in various ethnicities highlights the genetic complexity of the disease. Detailed subanalysis of disease phenotypes revealed the potential for prediction of extra-pulmonary organ involvement and therapy response based on the patient's genotype.

Association of HLA-DRB1 with Sarcoidosis Susceptibility and Progression in African Americans

HLA-DRB1 is a sarcoidosis risk gene, and the *03:01 allele is strongly associated with disease resolution in European sarcoidosis cases. Whereas the HLA-DRB1 variation is associated with sarcoidosis susceptibility in African Americans, DRB1 risk alleles are not as well defined, and associations with disease resolution have not been studied. Associations between genotyped and imputed HLA-DRB1 alleles and disease susceptibility/resolution were evaluated in a sample of 1,277 African-American patients with sarcoidosis and 1,467 control subjects. In silico binding assays were performed to assess the functional significance of the associated alleles. Increased disease susceptibility was associated with the HLA-DRB1 alleles *12:01 (odds ratio [OR], 2.11; 95% confidence interval [CI], 1.65-2.69; P = 3.2 × 10(-9)) and *11:01 (OR, 1.69; 95% CI, 1.42-2.01; P = 3.0 × 10(-9)). The strongest protective association was found with *03:01 (OR, 0.56; 95% CI, 0.44-0.73; P = 1.0 × 10(-5)). The African-derived allele *03:02 was associated with decreased risk of persistent radiographic disease (OR, 0.52; 95% CI, 0.37-0.72; P = 1.3 × 10(-4)), a finding consistent across the three component studies comprising the analytic sample. The DRB1*03:01 association with disease persistence was dependent upon local ancestry, with carriers of at least one European allele at DRB1 at a decreased risk of persistent disease (OR, 0.36; 95% CI, 0.14-0.94; P = 0.037). Results of in silico binding analyses showed that DRB1*03:01 consistently demonstrated the highest binding affinities for six bacterial peptides previously found in sarcoidosis granulomas, whereas *12:01 displayed the lowest binding affinities. This study has identified DRB1*03:01 and *03:02 as novel alleles associated with disease susceptibility and course in African Americans. Further investigation of DRB1*03 alleles may uncover immunologic factors that favor sarcoidosis protection and resolution among African Americans.

Association of serum TNF-α, IL-8 and free light chain with HLA-DR B alleles expression in pulmonary and extra-pulmonary sarcoidosis

Background

Sarcoidosis is a systemic disease of unknown etiology characterized histologically by the observation of non-caseating granulomas and several immunological abnormalities. Sarcoidosis is a multi-organ disorder which involves formation of granulomas in many tissues including the lungs (pulmonary) and others such as skin, bone, heart (extra pulmonary). Associations between human leukocyte antigens (HLA), the encoded cell surface receptor (HLA-DR) and sarcoidosis have been reported in several studies. Several HLA-DR alleles have been described as potential risk factors for sarcoidosis in distinct ethnic groups however evidence for a relationship between HLA-DR alleles and pulmonary and extra-pulmonary sarcoidosis (EPS) is still scarce. Although the etiology of the disease remains unclear, infectious and environmental factors have been postulated. Inflammatory cytokines and chemokines may play important roles in the pathogenesis of sarcoidosis and serum free light chain (FLC) numbers have been implicated in several immunologic disorders.

Purpose of the study

The aim of the present study was to investigate HLA associations with serum cytokines and FLC in Iranian patients with pulmonary (n = 86) and EPS (n = 46).

Results

We found that among the 16 HLA DRB alleles only *7 and *12 were different in sarcoidosis patients. The levels of TNF-α and IL-8 in pulmonary sarcoidosis patients were higher than in EPS (P < 0.05) whereas the levels of FLC subunits in EPS were higher than in pulmonary sarcoidosis.

Conclusion

This data may suggests a link between HLA-DRB *12 and sarcoidosis in Iranian population.

HLA in a cohort of Brazilian patients with sarcoidosis

Sarcoidosis is a multisystem granulomatous disorder of unknown etiology. Hereditary etiology has been proposed as a cause of the sarcoidosis, and some Human Leucocyte Antigen (HLA) alleles have been related to the diagnosis or severity of the disease. Löfgren's syndrome has been linked to patients with the DRB1*03 allele, and non-resolving disease has been associated with the DRB1*07, DRB1*14 and DRB1*15 alleles. However, the results observed in Caucasian patients are not reproducible in other populations, such as in Japanese individuals. The aim of this study is to examine the HLA alleles in Brazilian patients with sarcoidosis confirmed by biopsy. Sixty-three patients were included in the study, and the HLA alleles were compared with 126 control individuals. HLA-A, -B, -C, -DRB1 and -DQB1 genes were typed using a Luminex Multi-analyte profiling system (One Lambda, Inc. Canoga Park, CA). Among sarcoidosis patients, the HLA A*23, A*80, B*08, B*41, DQB1*05 and DRB1*14 antigens tended to be more common than in the controls, whereas the B*44, B*45, B*51, B*58, DRB1*15 and DRB1*16 alleles were more frequently found in control subjects than in the sarcoidosis patients. However, after Bonferroni correction, only the HLA-DRB1*14 allele was found to be significantly different between sarcoidosis patients and controls (pC=0.0047, OR=11.69, CI=2.47-55.22). This allele was more frequent in mestizos and black patients. The presence of an HLA-DRB1*14 allele might determine the risk of sarcoidosis in Brazilian individuals, especially in mestizos and black patients.

HLA distribution in COPD patients

BACKGROUND

Auto-immunity may contribute to the pathogenesis of chronic obstructive pulmonary disease (COPD), particularly to the presence of emphysema. Auto-immune diseases are characterized by an abnormal distribution of HLA class II alleles (DR and DQ). The distribution of DRB1 and DQB1 alleles has not been investigated in COPD.

METHODS

To this end, HLA medium-low resolution typing was performed following standardized protocols in 320 clinically stable COPD patients included in the PAC-COPD study. Results were compared with controls of the same geographical and ethnic origin, and potential relationships with the severity of airflow limitation and lung diffusing capacity impairment were explored in patients with COPD.

RESULTS

The distribution of DRB1 and DQB1 alleles in COPD was similar to that of controls except for a significantly higher prevalence of DRB1*14 in patients with severe airflow limitation and low diffusing capacity.

CONCLUSIONS

By and large, HLA distribution was similar in COPD patients and controls, but the HLA class II allele DRB1*14 may contribute to the pathogenesis of severe COPD with emphysema.

Human leukocyte antigen-A, -B, and -DRB1 alleles and sarcoidosis in Chinese Han subjects

Human leukocyte antigens (HLA) play a key role in antigen presentation. HLA genes, especially HLA-A, -B, and -DRB1, which are highly polymorphic, have been thought to be candidate loci for the etiology of sarcoidosis. This study aimed to assess the association between the polymorphism of HLA-A, -B, and -DRB1 alleles and sarcoidosis in Chinese Han subjects. Genomic DNA was extracted from 131 patients with sarcoidosis and 122 healthy controls. The polymorphisms of the HLA-A, -B, and -DRB1 alleles were determined using a polymerase chain reaction sequence-specific primer method. The frequency of allele HLA-DRB1*11 in sarcoidosis patients was significantly higher than that in controls (24.43% vs 4.92%, p/p(c) = 0.0001/0.002), whereas the frequencies of allele HLA-B*13 and HLA-DRB1*07 were markedly lower in sarcoidosis patients than in controls (12.21% vs 27.87%, p/p(c) = 0.002/0.045; 7.63% vs 22.95%, p/p(c) =0.001/0.009). HLA-B*51 was overrepresented in patients with erythema nodosum and Löfgren's syndrome (p < 0.001 [p(c) = 0.015], p < 0.0001 [p(c) < 0.001], respectively). These results support the hypothesis that HLA-A, -B, and -DRB1 polymorphisms may play a role in susceptibility and manifestation of sarcoidosis.

Sarcoidosis HLA class II genotyping distinguishes differences of clinical phenotype across ethnic groups

The HLA class II (DRB1 and DQB1) associations with sarcoidosis have been studied by several groups but often without consistent results. In this paper, we consider the hypothesis that observed inconsistencies relate to distinct, genetically encoded disease phenotypes which differ in prevalence between centres. We therefore typed HLA-DRB1 and DQB1 in 340 UK, 139 Dutch and 163 Japanese sarcoidosis patients and, respectively, 354, 218 and 168 healthy controls from these populations. We applied consistent phenotyping and genotyping and investigated associations between HLA class II alleles and distinct disease phenotypes within and between ethnic groups. DRB1*01 and DQB1*0501 are protective against all manifestations of sarcoidosis. Lung-predominant sarcoidosis is associated with DRB1*12 and *14. Löfgren's syndrome is a common sarcoidosis phenotype in the Dutch and is strongly associated with the DRB1*0301 allele. This phenotype is not seen among the Japanese in whom DRB1*0301 is absent. The same allele is protective for UK uveitis. Sarcoid uveitis is common in Japan. The DRB1*04-DQB1*0301 haplotype is a risk factor for this disease manifestation in Japanese and UK subjects but protective for sarcoidosis overall. We show that distinct sarcoidosis phenotypes have similar genetic associations across ethnic groups. The disease case mix differs between centres and may be explained by different ethnic allelic frequencies.

Gene expression profiling identifies MMP-12 and ADAMDEC1 as potential pathogenic mediators of pulmonary sarcoidosis

RATIONALE

Little is known about the genetic regulation of granulomatous inflammation in sarcoidosis.

OBJECTIVES

To determine if tissue gene array analysis would identify novel genes engaged in inflammation and lung remodeling in patients with sarcoidosis.

METHODS

Gene expression analysis was performed on tissues obtained from patients with sarcoidosis at the time of diagnosis (untreated) (n = 6) compared with normal lung tissue (n = 6). Expression of select genes was further confirmed in lung tissue from a second series of patients with sarcoidosis and disease-free control subjects (n = 11 per group) by semi-quantitative RT-PCR. Interactive gene networks were identified in patients with sarcoidosis using Ingenuity Pathway Analysis (Ingenuity Systems, Inc., Redwood, CA) software. The expression of proteins corresponding to selected overexpressed genes was determined using fluorokine multiplex analysis, and immunohistochemistry. Selected genes and proteins were then analyzed in bronchoalveolar lavage fluid in an independent series of patients with sarcoidosis (n = 36) and control subjects (n = 12).

MEASUREMENTS AND MAIN RESULTS

A gene network engaged in Th1-type responses was most significantly overexpressed in the sarcoidosis lung tissues, including genes not previously reported in the context of sarcoidosis (e.g., IL-7). MMP-12 and ADAMDEC1 transcripts were most highly expressed (> 25-fold) in sarcoidosis lung tissues, corresponding with increased protein expression by immunohistochemistry. MMP-12 and ADAMDEC1 gene and protein expression were increased in bronchoalveolar lavage samples from patients with sarcoidosis, correlating with disease severity.

CONCLUSIONS

Tissue gene expression analyses provide novel insights into the pathogenesis of pulmonary sarcoidosis. MMP-12 and ADAMDEC1 emerge as likely mediators of lung damage and/or remodeling and may serve as markers of disease activity.

Association between human leukocyte antigen class II alleles and human papillomavirus-mediated cervical cancer in Indian women

We investigated the association of human leukocyte antigen (HLA) II (DRB1 and DQB1) alleles with susceptibility to human papillomavirus (HPV)-associated cervical precancer and cancer cases in a hospital-based case-control study in a northern Indian population. A total of 202 subjects, including 100 patients comprising 31 cervical precancer (cervical intraepithelial neoplasia [CIN] 2/3) and 69 invasive cervical cancer cases, and 102 healthy controls participated in the study. Both patients and controls were screened for HPV infection using a polymerase chain reaction (PCR-based approach. Low-resolution PCR-sequence specific priming (PCR-SSP) was used to genotype HLA II (DRB1 and DQB1). Our results demonstrate that the DRB1*15 allele/DRB1*15-DQB1*06 haplotype may have a predisposition for HPV infection (p(c) < 0.05) or cervical cancer/precancer (p(c) < 0.05) development, whereas the DRB1*04 allele/DRB1*04-DQB1*03 haplotype might exhibit susceptibility to cervical precancerous lesions (p(c) < 0.05). The DRB1*13 allele/DRB1*13-DQB1*06 haplotype was strongly protective against risk to HPV infection (p(c) < 0.002) as well as cervical cancer (p(c) 0.01). Therefore, we have demonstrated that HLA DR-DQ polymorphisms are involved in genetic susceptibility to cervical cancer or HPV infection in a northern Indian population.

Association of TNF polymorphisms with sarcoidosis, its prognosis and tumour necrosis factor (TNF)-alpha levels in Asian Indians

Tumour necrosis factor (TNF)-alpha, an important proinflammatory cytokine, has been implicated in the pathogenesis of sarcoidosis, a multi-systemic granulomatous disorder of unknown aetiology. Here, we report for the first time the association of TNF haplotypes and genotypes with sarcoidosis and its prognosis in the Indian population. Five potentially functional promoter polymorphisms in the TNFA gene and a LTA_NcoI polymorphism (+252 position) of the LTA gene were genotyped in a clinically well-defined cohort of North-Indian patients with sarcoidosis (n = 96) and their regional controls (n = 155). Serum TNF-alpha (sTNF-alpha) and serum angiotensin converting enzyme (SACE) levels were measured and correlated with genotypes and haplotypes. The TNFA_-1031 and TNFA_-863 polymorphisms were identified as markers for disease onset (FET P = 0.006 and 0.042 for TNFA_-1031 and TNFA_-863, respectively). Additionally, the allele A of LTA_NcoI polymorphism was shown to be prevalent in the 'no treatment' group (FET P = 0.005), while the G allele was associated with frequent relapses on drug withdrawal (P = 0.057). Furthermore, the TNFA-308G>A and the TNFA-238G>A polymorphisms were found to influence sTNF-alpha (P = 0.054 and 0.0005, respectively) and SACE levels (P = 0.0017 and 0.056, respectively). The haplotype frequencies were significantly different in the patients and the controls (P = 0.0067). The haplotype GTCCGG was identified as the major risk/susceptibility haplotype (P = 0.003) and was associated with increased SACE levels in the patient population. In conclusion, our study suggests an association of TNF polymorphisms with sarcoidosis.

HLA class I and class II frequencies in patients with sarcoidosis from Croatia: role of HLA-B8, ?DRB1*0301, and ?DQB1*0201 haplotype in clinical variations of the disease

Sarcoidosis is an immune-mediated, multiorgan, granulomatous disease triggered by a combination of environmental and genetic factors. Numerous studies have reported about an association of human leukocyte antigen (HLA) alleles with sarcoidosis, with variation of alleles in different ethnic groups. Therefore, we investigated 142 Croatian sarcoidosis patients treated at the University Hospital for Lung Diseases Jordanovac, Zagreb, Croatia. Diagnosis was based on the presence of typical clinical features, chest X-ray findings and biopsy evidence of granuloma. Patients and control subjects (n = 190) were typed for HLA class I antigens by serology, while for HLA class II, they were tested by the polymerase chain reaction-sequence specific primers (PCR-SSP) method. Results indicated that HLA-B8, -DRB1*0301, and -DQB1*0201 positive patients have a significantly higher risk of acute onset of the disease (AOD), radiological stage I erythema nodosum (EN), Löfgren's syndrome, no-medicament therapy, and pulmonary sarcoidosis. On the other hand, the group of non-treated patients (corticosteroids and/or immunosuppressive) showed a significantly lower presence of HLA-B15 antigen in comparison to controls and treated patients (P = 0.0490 and P = 0.0379, respectively) and for DRB1*04 specificity (P = 0.0078 and P = 0.0065, respectively). In the group of patients with AOD, those who were positive for DRB1*16 specificity have a statistically significant chance to develop EN, as opposed to those who are positive for DRB1*15 specificity.

Sarcoidosis in Singapore: epidemiology, clinical presentation and ethnic differences

BACKGROUND AND OBJECTIVES

The aim of this study is to better understand the epidemiological and clinical features of patients with sarcoidosis in Singapore and to ascertain if ethnic differences exist.

METHODS

A review of hospital medical records from June 1998 to May 2004 to identify patients with sarcoidosis.

RESULTS

There were 59 patients with sarcoidosis identified (19 Chinese, 29 Asian Indian and 11 Malay). The estimated annual incidence of sarcoidosis in Singapore was 0.56 per 100,000. There was a significant difference between the observed and expected disease frequency in Chinese (32.2% vs 78.7%) and Indians (49.2% vs 6.0%, P < 0.005). A bimodal distribution of age at diagnosis was seen with peaks in the 30-39 years and 50-59 years age groups; 38.9% of cases were over the age of 50. Chinese patients were more likely to be asymptomatic (57.9%, P = 0.015) and less likely to have impaired spirometry (P = 0.013). Pulmonary sarcoid presented largely as stage 0 or stage 1 disease (74.4%). Overall mean spirometry was unimpaired and prognosis was good with 79.2% showing no radiological deterioration. There were no significant differences in organ involvement or treatment between ethnic groups.

CONCLUSION

Sarcoidosis in Singapore is rare and the incidence differs between ethnic groups. Chinese appear to have a lower incidence and a less symptomatic presentation; Indians have a higher incidence and poorer clinical course.

DQA1*03011 allele: protective or an adverse effect on the development of sarcoidosis; preliminary study

BACKGROUND

Sarcoidosis (SA) is a multisystem granulomatous disorder of unknown etiology. It seems likely that in genetically different predisposed hosts, the same antigen(s) may cause the development of sarcoid Th1 response. The interaction of the T-cell receptor with the human leukocyte antigen-DQA1*03011 peptide-complex can affect T lymphocytes activation in a dose-response manner.

OBJECTIVES/METHODS

To test occurrence of DQA1*03011 allele in SA, we compared the distribution of DQA1 alleles in 32 SA patients, 37 TB patients and in 58 healthy volunteers, using a PCR-SSP "high-resolution" method.

RESULTS

Our results revealed that after Bonferroni correction DQA1*03011 were less common in SA patients than in the controls (OR 0.16, 95%CI 0.03-0.75). In TB, DQA1*0303 were significantly more frequent and DQA1*0505 less present as compared to the controls (OR 11.03, 95% CI 1.20-95.80, OR 0.29, 95% CI 0.01-0.88). Comparing DQA1 alleles in both patient groups, DQA1*0501, DQA1*0505 alleles were more common and DQA1*03011, DQA1*0302, DQA1*0303 were less common after Bonferroni correction in SA than in TB.

CONCLUSION

We revealed that DQA1*03011 allele was less common in SA than in the controls and TB. It seems possible that a low frequency of DQA1*03011 occurrence may be also involved in the etiopathogenesis of SA.

Generic human leukocyte antigen class II (DRB1 and DQB1) alleles in patients with paracoccidioidomycosis

Human leukocyte antigen (HLA) class II alleles are involved in antigen processing and in the presentation of antigens to T lymphocytes. Few studies have investigated HLA genes in paracoccidioidomycosis. In the present investigation, we analyzed the distribution of the HLA class II alleles DRB1 and DQB1 in 45 healthy volunteers and in 80 patients with paracoccidioidomycosis. The patients presented with various clinical forms of the disease, and allele distribution was evaluated individually in each presentation type. In patients with the unifocal chronic form of the disease, a mild clinical presentation in which lesions are restricted or localized, the HLA allele most commonly seen was DRB1*11 (p<0.039). This suggests that the participation of HLA antigens may influence the outcome of the host-parasite interaction in paracoccidioidomycosis, regulating the immune response to Paracoccidioides brasiliensis antigens.

A New Tool To Assess Sarcoidosis Severity

STUDY OBJECTIVES

Sarcoidosis is a granulomatous disorder primarily affecting the lung, but with frequent extrapulmonary organ involvement. There are no comprehensive scoring systems for sarcoidosis disease severity. Our goal was to develop and validate an objective and comprehensive sarcoidosis disease severity scoring system.

DESIGN

Three sarcoidosis experts reviewed clinical data on 104 patients with biopsy-confirmed sarcoidosis. Each expert independently scored disease severity using a visual analog scale. Interrater agreement was assessed. Univariate analysis was performed, and those variables with p values < or = 0.25 were used in backward regression multivariable analysis. A model was obtained including variables with a p value of < or = 0.15 to predict severity scores. This model was subsequently validated using an independent panel of three additional international experts.

SETTING

Granuloma clinic at National Jewish Medical and Research Center.

PATIENTS

A total of 104 patients with biopsy-confirmed sarcoidosis.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

Pairwise assessment of interrater agreement yielded high degrees of correlation with Spearman correlation coefficients of 0.86 to 0.89 and an intraclass correlation coefficient of 0.87. Univariate analysis showed that smoking status, immunosuppressive therapy, percent predicted for diffusing capacity of the lung for carbon monoxide (Dlco), FEV1, FVC, and total lung capacity, FEV1/FVC ratio, disease duration, sites of organ involvement, and African-American race were associated with mean severity score. The multivariable model included cardiac and neurologic involvement, current therapy with noncorticosteroid immunosuppressive agents, Dlco percent predicted, FEV1/FVC ratio, African-American race, FVC percent predicted, and skin involvement. This model was validated using additional reviewer scores yielding Spearman correlation coefficients of 0.66 to 0.76 and an intraclass correlation coefficient of 0.74.

CONCLUSIONS

We derived an objective disease severity scoring system that incorporates data on demographics, pulmonary function, and organ involvement to produce a whole-body sarcoidosis assessment. This preliminary tool has potential applicability in the assessment of disease severity in sarcoidosis research.

The impact of variation at the KIR gene cluster on human disease

Leukocyte behavior is controlled by a balance of inhibitory and stimulatory signals generated on ligand binding to a complex set of receptors located on the cell surface. The killer cell immunoglobulin-like receptor (KIR) genes encode one such, family of receptors expressed by natural killer (NK) cells, key components of the innate immune system that participate in early responses against infected or transformed cells through production of cytokines and direct cytotoxicity. KIRs are also expressed on a subset of T cells, where they contribute to the intensity of acquired immune responses. Recognition of self HLA class I ligands by inhibitory KIR allows NK cells to identify normal cells, preventing an NK cell-mediated response against healthy autologous cells. Activation of NK cells through stimulatory receptors is directed toward cells with altered expression of class I, a situation characteristic of some virally infected cells and tumor cells. The "missing self" model for NK cell activation was proposed to explain killing of cells that express little or no class I, while cells expressing normal levels of class I are spared. Studies performed over the last several years have revealed extensive diversity at the KIR gene locus, which stems from both its polygenic (variable numbers of genes depending on KIR haplotype) and multiallelic polymorphism. Given the role of KIR in both arms of the immune response, their specificity for HLA class I allotypes, and their extensive genomic diversity, it is reasonable to imagine that KIR gene variation affects resistance and susceptibility to the pathogenesis of numerous diseases. Consequently, the evolution of KIR locus diversity within and across populations may be a function of disease morbidity and mortality. Here we review a growing body of evidence purporting the influence of KIR polymorphism in human disease.

Involvement of discoidin domain receptor 1 in the deterioration of pulmonary sarcoidosis

The prognosis of sarcoidosis with pulmonary infiltrates differs in each case, and several cytokines are reported to contribute to its deterioration. However, the detailed mechanism has not been fully elucidated. Discoidin domain receptor 1 (DDR1) is a receptor tyrosine kinase activated by collagen and associated with cytokine production from inflammatory cells. We previously reported the functional expression of DDR1 on CD14-positive bronchoalveolar lavage fluid (BALF) cells in vivo. In this study, we hypothesized that DDR1 might be associated with the deterioration of pulmonary sarcoidosis (PS), and investigated 33 patients with sarcoidosis with pulmonary infiltrates, prospectively. We found that patients with deteriorated PS showed significantly higher DDR1 expression in CD14-positive BALF cells predominant with DDR1b isoforms. Activation of DDR1 induced monocyte chemoattractant protein-1 (MCP-1) and matrix metalloproteinase-9 (MMP-9) production in a p38 mitogen-activated protein kinase-dependent manner from CD14-positive BALF cells of patients with deteriorated sarcoidosis. DDR1 activation also induced NF-kappaB nuclear translocation in CD14-positive BALF cells of patients with deteriorated PS. The inhibitor of NF-kappaB inhibited the production of MCP-1 and MMP-9. We propose that DDR1 is associated with the deterioration of pulmonary sarcoidosis.

Severe Pulmonary Sarcoidosis Is Strongly Associated With the Haplotype HLA-DQB1*0602–DRB1*150101

Sarcoidosis is a multiorgan granulomatous disease of unknown etiology. Several lines of evidence suggest a genetic predisposition and associations have been demonstrated with HLA antigens. HLA-DQB1 has been proposed as one of the candidate genes. To investigate the relationship between DQB1 and sarcoidosis at the allele level, we typed 149 Dutch Caucasian sarcoidosis patients for DQB1 by sequence-based typing as the ultimate technique to identify all DQB1 alleles. Phenotype frequencies were compared with controls. Both groups were also typed for HLA-A, -B, and -DRB1 at the low-resolution level. To decide on the possible linkage with DR, all DRB1*15-positive patients were subsequently sequence-based typed. Results showed a statistically significant increase of DQB1*0602 in sarcoidosis patients. The increase was also proven for DRB1*150101. Because of the high linkage disequilibrium between DRB1*1501 and DQB1*0602 in Caucasians, it could not be decided which one was the primary association. The increase was most pronounced in patients with severe pulmonary sarcoidosis indicated by radiographic stages II-IV. Although not statistically significant, DRB1*03 and DQB1*0201 were increased in radiographic stage I compared with II-IV. This study provides evidence that the combination DQB1*0602/DRB1*150101 is a strong positive marker for severe pulmonary sarcoidosis.

[Update on sarcoidosis]

Since the first description more than a century ago, intensive research continues to focus on sarcoidosis. Based on our current knowledge, sarcoidosis can be considered as an immune syndrome resulting from a variable combination of predisposing genetic, ethnic, and environmental factors. Over the last few years, several teams have proposed a link between certain genetic polymorphisms, particularly of the HLA system, and the risk of development or progression of sarcoidosis. Other pathogenic mechanisms involved in the formation of the sarcoid granuloma are becoming more clear and have led to the development of new therapeutic approaches such as anti-TNF currently being evaluated in multicentric trials.

[Human leukocyte antigens A and B in Turkish patients with sarcoidosis]

OBJECTIVE

Associations between human leukocyte antigens (HLA) and sarcoidosis have been reported in several studies. We aimed to investigate these associations in Turkish patients.

PATIENTS AND METHOD

We performed HLA-A, HLA-B, HLA-C, and HLA-D typing in 83 patients with sarcoidosis and in 250 healthy controls using a microlymphocytotoxicity method to investigate genetic susceptibility to the disease.

RESULTS

Because of significant violation of Hardy-Weinberg equilibrium at HLA-C and HLA-DQB1 loci, only results obtained at other HLA loci were used. Although HLA-A9, HLA-B5, and HLA-B8 allele frequencies were significantly higher in the patient group compared to the controls (odds ratio [OR]= 21.8, P= .015; OR= 9.34, P= .049; OR= 2.26, P= .031, respectively), none of the differences remained significant after applying the Bonferroni correction. HLA-A24, HLA-A26, and HLA-B62 alleles were significantly less frequent in the patient group compared to the controls (OR= 0.48, P= .018; OR= 0.19, P= .003; OR= 0.11, P= .044, respectively). However, the differences also failed to remain significant after Bonferroni correction.

CONCLUSIONS

These results suggest that both HLA may play significant roles (either increasing or reducing risk) in the pathogenesis of sarcoidosis and in its distinct clinical forms and laboratory findings.