Association between IFNA genotype and the risk of sarcoidosis

Discovering the link between IL12RB1 gene polymorphisms and tuberculosis susceptibility: a comprehensive meta-analysis

Introduction

Numerous studies suggest that the risk of tuberculosis (TB) is linked to gene polymorphisms of the interleukin-12 receptor b subunit 1 (IL12RB1), but the association between IL12RB1 polymorphisms and TB susceptibility has not been thoroughly investigated.

Methods

A meta-analysis was conducted based on eight case-control studies with 10,112 individuals to further explore this topic. A systematic search of PubMed, Web of Science, Excerpt Medica Database, and Google Scholar up until April 6th, 2023 was performed. ORs and 95% CIs were pooled using the random-effect model. The epidemiological credibility of all significant associations was assessed using the Venice criteria and false-positive report probability (FPRP) analyses.

Results

The IL12RB1 rs11575934 and rs401502 showed solid evidence of no significant association with TB susceptibility. However, a weak association was observed between the IL12RB1 rs375947 biomarker and pulmonary tuberculosis (PTB) susceptibility (OR = 1.64, 95% CI: 1.22, 2.21).

Discussion

These findings should be confirmed through larger, better-designed studies to clarify the relationship between biomarkers in IL12RB1 gene and different types of TB susceptibility.

Anti-inflammatory Properties of the Alpha-Melanocyte-Stimulating Hormone in Models of Granulomatous Inflammation

Purpose

Alpha-melanocyte stimulating hormone (α-MSH) is known to have anti-inflammatory effects. However, the anti-inflammatory properties of α-MSH on normal bronchial epithelial cells are largely unknown, especially in the context of in vitro sarcoidosis models.

Methods

We evaluated the anti-inflammatory effects of α-MSH on two different in vitro sarcoidosis models (lung-on-membrane model; LOMM and three-dimensional biochip pulmonary sarcoidosis model; 3D-BSGM) generated from NBECs and an in vivo sarcoidosis mouse model.

Results

Treatment with α-MSH decreased inflammatory cytokine levels and downregulated type I interferon pathway genes and related proteins in LOMM and 3D-BSGM models. Treatment with α-MSH also significantly decreased macrophages and cytotoxic T-cells counts in a sarcoidosis mice model.

Conclusion

Our results confirm the direct role of type I IFNs in the pathogenesis of sarcoid lung granulomas and highlight α-MSH as a potential novel therapeutic agent for treating pulmonary sarcoidosis.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s00408-022-00546-x.

Drug-induced Sarcoid Uveitis with Biologics

Purpose/Objectives: to evaluate new onset uveitis or reactivated uveitis by biologic agents and characterize their features.Materials and Methods: This is a multicenter, retrospective case series. Patients under biologic therapy were included if they developed uveitis for the first time or experienced intraocular inflammation which was different in location or laterality to previous inflammation.Results: Sixteen patients were identified. The underlying disorders included ankylosing spondylitis, juvenile idiopathic arthritis, rheumatoid arthritis, and Behçet's Disease. The biologic agents associated with a first episode of uveitis (n = 11) or with a new recurrence of uveitis (n = 5) were etanercept, adalimumab, abatacept, infliximab, and golimumab. Sarcoidosis based on bihilar lymphadenopathy, other computer tomography-findings, or biopsy was diagnosed in five patients under therapy with etanercep, adalimumab, and abatacept. Additionally, seven patients developed clinical changes in their uveitis pattern, suggesting sarcoid uveitis.Conclusions: Biologic treatment-induced uveitis often presents as granulomatous disease.

Drug-Induced Sarcoidosis-Like Reactions

A drug-induced sarcoidosis-like reaction (DISR) is a systemic granulomatous reaction that is indistinguishable from sarcoidosis and occurs in a temporal relationship with initiation of an offending drug. DISRs typically improve or resolve after withdrawal of the offending drug. Four common categories of drugs that have been associated with the development of a DISR are immune checkpoint inhibitors, highly active antiretroviral therapy, interferons, and tumor necrosis factor-α antagonists. Similar to sarcoidosis, DISRs do not necessarily require treatment because they may cause no significant symptoms, quality of life impairment, or organ dysfunction. When treatment of a DISR is required, standard antisarcoidosis regimens seem to be effective. Because a DISR tends to improve or resolve when the offending drug is discontinued, this is another effective treatment for a DISR. However, the offending drug need not be discontinued if it is useful, and antigranulomatous therapy can be added. In some situations, the development of a DISR may suggest a beneficial effect of the inducing drug. Understanding the mechanisms leading to DISRs may yield important insights into the immunopathogenesis of sarcoidosis.

Familial sarcoidosis: Report of a mother and her son

Sarcoidosis is a chronic, multisystemic inflammatory disease, characterized with noncaseating granulomas. The pathogenesis of the disease is not yet clear, however, the main hypothesis is impaired and inadequate immune response developing against different environmental triggers in genetically predisposed people. The role of genetic factors in the development of sarcoidosis is well known. Over many years, familial sarcoidosis cases have been reported in various studies. In this report, we present familial sarcoidosis cases in a mother and her son.

Plasmacytoid dendritic cells in cutaneous sarcoidosis

While absent from normal skin, plasmacytoid dendritic cells (pDCs) infiltrate the skin in several infectious, inflammatory, and neoplastic entities. In addition to providing anti-viral resistance, pDCs link the innate and adaptive immune responses. Sarcoidosis is an idiopathic multi-system granulomatous disease characterized by epitheliod granulomas. Its underlying immunopathogenesis involves hyperactivity of cell-mediated immune system with involvement of CD4+ T-helper cells of the Th1 subtype. Recently, pDCs have been shown to contribute to other cutaneous granulomatous disorders such as granuloma annulare (GA). Here, we intend to investigate pDC occurrence and activity in cutaneous sarcoidosis. Twenty cutaneous sarcoidosis cases and a comparable group of 20 cases of GA were retrieved from our database and were immunohistochemically tested for pDC occurrence and activity using anti-BDCA-2 and anti-MxA antibodies, respectively. Fifteen cases of cutaneous lupus erythrematosus (LE) were used as a comparison group. A semi-quantitative scoring system was used. pDCs were present in all cutaneous sarcoidosis in peri-vascular and/or peri-adnexal location admixed with lymphocytes. pDC numbers in sarcoidosis were comparable to those in GA, while pDCs were significantly more abundant in LE. MxA expression was mostly patchy in cutaneous sarcoidosis and GA cases, while LE cases showed diffuse and strong MxA expression. In conclusion, we have shown that pDCs are recruited into the skin lesions of sarcoidosis and GA. Despite the diminished type I IFN production demonstrated in our study, the consistent presence of pDCs in all cutaneous sarcoidosis cases speaks in favor of some role of these cells in the pathogenesis of granulomatous disorders. (Sarcoidosis Vasc Diffuse Lung Dis 2018; 35: 55-61).

The association between osteopontin gene polymorphisms, osteopontin expression and sarcoidosis

Background

Sarcoidosis is a systemic inflammatory disease of unknown etiology. Osteopontin (SPP1, OPN) is an extra cellular matrix glycoprotein and cytokine with a known role in granuloma formation and in autoimmune and inflammatory diseases.

Objective

To determine whether plasma OPN levels are elevated in patients with sarcoidosis and compare the frequency of four single nucleotide polymorphism (SNPs) variants in the OPN gene in sarcoidosis patients compared to healthy controls.

Methods

Demographic and clinical information, radiological studies and pulmonary function tests were evaluated in 113 patients with sarcoidosis and in 79 healthy controls. Blood samples were analyzed for SNPs of the OPN gene and for plasma OPN and CRP levels. Association between clinical features of disease and OPN levels as well as SNP frequencies was determined.

Results

Plasma OPN levels were higher in sarcoidosis patients than in healthy subjects, (median: 217 vs 122ng/ml, p<0.001). Area under the curve for receiver operator curves (ROC) was 0.798 (0.686–0.909 95% CI.) No differences were observed between sarcoidosis patients and controls in the frequency of any of the SNPs evaluated. Presence of lung parenchymal involvement was associated with SNP distribution at rs1126772 (p = 0.02). We found no correlation between SNPs distribution and plasma OPN levels.

Conclusions

Osteopontin protein levels are elevated in sarcoidosis. We found no evidence for an association between SNPs on the osteopontin gene and plasma OPN levels or the presence of sarcoidosis, however, an association between genotype and several phenotypic clinical parameters of disease was observed.

Relationship between IFNA1, IFNA5, IFNA10, and IFNA17 gene polymorphisms and Crimean-Congo hemorrhagic fever prognosis in a Turkish population range

Crimean-Congo hemorrhagic fever (CCHF) is a fatal emerging acute viral infection. Not much is known regarding the pathogenic mechanisms and the reasons behind severe or mild disease courses in CCHF. IFN-alpha (IFNA) is one of the essential cytokines in the immune system. Existence of single nucleotide gene polymorphisms (SNPs) in cytokines can cause susceptibility or resistance to viral agents and different clinical courses. Hence, the relationship between SNPs in genes encoding cytokines (IFNA1 -1823G/A (rs1332190), IFNA5 -2529T/A (rs758236), IFNA10 Cys20stop (rs10119910), and IFNA17 Ile184Arg (rs9298814) SNPs and disease susceptibility were investigated. The associations between SNPs and CCHF prognosis were also studied. Total 150 patients with CCHF and 170 healthy individuals were enrolled. Genotyping was performed by PCR-RFLP methods. The frequency of IFNA1 -1823 (rs1332190) GG genotype was significantly higher in control subjects than CCHF patients (20% vs. 8%; P = 0.01). For IFNA17 Ile184Arg (rs9298814) polymorphism, CCHF patients having TG genotype had a higher frequency than the control subjects (38% vs. 32.4%; P = 0.039). The distribution of TT + TG genotype frequencies was also significantly higher in CCHF group than the controls (97.3% vs. 91.8%; P = 0.049). Genotype and allele frequencies for IFNA subtypes between fatal and survivors were the same (P > 0.05). Genotype and allele frequencies between severe and mild/moderate CCHF patients were also the same (P > 0.05). The results show that IFNA1 rs1332190 and IFNA17 rs9298814 SNPs may play an important role in CCHF susceptibility. Determining the existence of other connections for IFNA SNPs and CCHF severity and fatality requires further investigations.

Identifying Novel Biomarkers in Sarcoidosis Using Genome-Based Approaches

This article briefly reviews conventional biomarkers used clinically to (1) support a diagnosis and (2) monitor disease progression in patients with sarcoidosis. Potential new biomarkers identified by genome-wide screening and the approaches to discover these biomarkers are described.

Endogenously produced TNF-α contributes to the expression of CXCL10/IP-10 in IFN-λ3-activated plasmacytoid dendritic cells

The interplay between IFN-λs and dendritic cells is becoming increasingly relevant, particularly in light of their key role in inducing the antiviral state, including in hepatitis C virus infection. In this work, we have analyzed extensively how human plasmacytoid dendritic cells respond to IFN-λ3. We report that plasmacytoid dendritic cells incubated with IFN-λ3 prolong their survival; alter their expression pattern of surface HLA-DRα, CD123, CD86, and CD303; and time dependently produce IFN-α, CXCL10/IFN-γ-induced protein 10, and even modest quantities of TNF-α. Nevertheless, endogenously produced TNF-α, but not IFN-α, was found to be essential for driving the expression of CXCL10/IFN-γ-induced protein 10 in IFN-λ3-treated plasmacytoid dendritic cells, as revealed by neutralizing experiments by use of adalimumab, etanercept, and infliximab. We also observed that based on the kinetics and levels of IFN-α and CXCL10/IFN-γ-induced protein 10 produced by their IFN-λ3-treated plasmacytoid dendritic cells, healthy donors could be categorized into 2 and 3 groups, respectively. In particular, we identified a group of donors whose plasmacytoid dendritic cells produced modest quantities of CXCL10/IFN-γ-induced protein 10; another one whose plasmacytoid dendritic cells produced elevated CXCL10/IFN-γ-induced protein 10 levels, already after 18 h, declining thereafter; and a 3rd group characterized by plasmacytoid dendritic cells releasing very high CXCL10/IFN-γ-induced protein 10 levels after 42 h only. Finally, we report that in plasmacytoid dendritic cells, equivalent concentrations of IFN-λ3 and IFN-λ1 promote survival, antigen modulation, and cytokine production in a comparable manner and without acting additively/synergistically. Altogether, data not only extend the knowledge on the biologic effects that IFN-λs exert on plasmacytoid dendritic cells but also add novel light to the networking between IFN-λs and plasmacytoid dendritic cells in fighting viral diseases.

Interferon-γ (IFNG) microsatellite repeat and single nucleotide polymorphism haplotypes of IFN-α receptor (IFNAR1) associated with enhanced malaria susceptibility in Indian populations

Pro-inflammatory cytokines IFNγ and IFNα function through their cellular receptors IFNγR1 and IFNαR1, respectively to mediate immune processes during malaria infection. A total of 21 SNPs, 2 ins/del polymorphisms and a microsatellite repeat, selected on the basis of their reported association with infectious diseases including malaria in world populations, were analysed for association with Plasmodium falciparum malaria susceptibility in a case-control study with adult patients and ethnically-matched controls drawn from a disease meso- to hyperendemic and a nonendemic region of India. Among the five IFNG SNPs tested, an intron 3 and a 3'UTR SNP associated with disease in the endemic region. In addition, large (CA)n repeats of IFNG intron 1 associated with protection from severe malaria in the endemic region (severe vs. control, odds ratio=0.21, 95% CI=0.08-0.52, P=1.3 × 10(-4)). The TA11CAG haplotype (rs2069705 T/C, rs2430561 A/T, rs3138557 (CA)n, rs2069718 T/C, rs2069727 A/G, rs2069728 G/A) carrying a short CA11 repeat also exhibited very strong association with severe malaria, particularly in the endemic region (severe vs. control, OR=14.56, 95% CI=3.39-85.81, P=3 × 10(-5)). One SNP each from the IFNA8 and IFNA17 of IFNA gene cluster had a protective effect in the non-endemic region but not in the endemic region. A promoter and an intron 2 SNP of IFNAR1 were risk factors for disease and the IFNAR1 haplotype GCCAGG (rs2843710 C/G, rs2850015 C/T, +6993 C/T, rs2243594 A/G, rs1012335 G/C, rs2257167 G/C) carrying both the risk alleles strikingly associated with disease manifestation in the endemic region (severe vs. control, OR=27.14, 95% CI=3.12-1254, P=2 × 10(-5); non-severe vs. control, OR=61.87, 95% CI=10.08-2521, P=1 × 10(-8)). The data indicates dissimilar contribution of cytokine and cytokine receptor variants to disease in populations residing in areas of differential malaria endemicity.

Interferon regulatory factor 5 polymorphisms in sarcoidosis

OBJECTIVE

Interferon regulatory factor 5 (IRF5) gene polymorphisms are associated with susceptibility to autoimmune diseases. The aim of this study is to determine the roles of IRF5 single-nucleotide polymorphisms (SNPs) in sarcoidosis.

METHODS

A total of 175 Japanese patients with biopsy-proven sarcoidosis and 150 sex-matched controls were genotyped for four IRF5 SNPs: rs729302A/C, rs2004640G/T, rs10954213A/G, and rs2280714G/A. The associations of these SNPs with susceptibility to sarcoidosis were examined.

RESULTS

Carriage of rs10954213A and rs2280714A conferred significant risks for sarcoidosis [carriage of rs10954213A: odds ratio (OR) = 1.96, 95% confidence interval (CI) = 1.15-3.33, P = 0.01, corrected P = 0.04; carriage of rs2280714A: OR = 1.97, 95% CI = 1.22-3.16, P = 0.005, corrected P = 0.02]. The haplotype carrying rs10954213A and rs2280714A (haplotype 2) was significantly associated with susceptibility to sarcoidosis (OR = 2.00, 95% CI = 1.24-3.24, P = 0.004, corrected P = 0.01). rs729302 and rs2004640 were not associated with susceptibility to sarcoidosis, whereas carriage of rs2004640G was protective against pulmonary hypertension (OR = 0.017, 95% CI = 0.002-0.15, P < 0.001, corrected P < 0.001).

CONCLUSION

A haplotype carrying two functional SNPs of IRF5, rs10954213A and rs2280714A, was associated with the risk of sarcoidosis in the Japanese population.

Influence of genetic variants in type I interferon genes on melanoma survival and therapy

Melanoma is an immunogenic tumor; however, the efficacy of immune-therapy shows large inter-individual variation with possible influence of background genetic variation. In this study we report the influence of genetic polymorphisms in the type I interferon gene cluster on chromosome 9p22 on melanoma survival. We genotyped 625 melanoma patients recruited in an oncology center in Germany for 44 polymorphisms located on chromosome 9p22 that were informative for 299 polymorphisms and spanned 15 type I interferon genes. Our results showed associations between time to metastasis/survival and two linked (r² = 0.76) polymorphisms, rs10964859 (C>G) and rs10964862 (C>A). The rs10964859 polymorphism was located at 3′UTR and rs10964862 was 9.40 Kb towards 5′UTR of IFNW1 gene. The carriers of the variant alleles of the rs10964859 and rs10964862 polymorphisms were associated with a reduced disease-free survival. The validation of data in an independent group of 710 patients from Spain showed that the direction of the effect was similar. Stratification based on therapy showed that the adverse effect on metastasis development was statistically significant in the patients from Spain who did not receive any treatment and were homozygous for variant allele of rs10964862 (HR = 2.52, 95% CI 1.07–5.90; P = 0.03). Patients homozygous for rs10964859 (HR = 2.01, 95% CI 1.17–3.44; P = 0.01) and rs10964862 (HR 1.84, 95%CI 1.03–3.27, P = 0.04) were associated to increased risk of death following metastasis. GTCGACAA haplotype, found in 8.8% of the patients, was associated with an increased risk of death (HR 1.94, 95%CI 1.16–3.26, P = 0.01). In conclusion, our results identified genetic variants in interferon genes that influence melanoma progression and survival with modulation of effect due to treatment status.

Peripheral blood gene expression as a novel genomic biomarker in complicated sarcoidosis

Sarcoidosis, a systemic granulomatous syndrome invariably affecting the lung, typically spontaneously remits but in ~20% of cases progresses with severe lung dysfunction or cardiac and neurologic involvement (complicated sarcoidosis). Unfortunately, current biomarkers fail to distinguish patients with remitting (uncomplicated) sarcoidosis from other fibrotic lung disorders, and fail to identify individuals at risk for complicated sarcoidosis. We utilized genome-wide peripheral blood gene expression analysis to identify a 20-gene sarcoidosis biomarker signature distinguishing sarcoidosis (n = 39) from healthy controls (n = 35, 86% classification accuracy) and which served as a molecular signature for complicated sarcoidosis (n = 17). As aberrancies in T cell receptor (TCR) signaling, JAK-STAT (JS) signaling, and cytokine-cytokine receptor (CCR) signaling are implicated in sarcoidosis pathogenesis, a 31-gene signature comprised of T cell signaling pathway genes associated with sarcoidosis (TCR/JS/CCR) was compared to the unbiased 20-gene biomarker signature but proved inferior in prediction accuracy in distinguishing complicated from uncomplicated sarcoidosis. Additional validation strategies included significant association of single nucleotide polymorphisms (SNPs) in signature genes with sarcoidosis susceptibility and severity (unbiased signature genes - CX3CR1, FKBP1A, NOG, RBM12B, SENS3, TSHZ2; T cell/JAK-STAT pathway genes such as AKT3, CBLB, DLG1, IFNG, IL2RA, IL7R, ITK, JUN, MALT1, NFATC2, PLCG1, SPRED1). In summary, this validated peripheral blood molecular gene signature appears to be a valuable biomarker in identifying cases with sarcoidoisis and predicting risk for complicated sarcoidosis.

Sarcoidosis triggered by interferon-Beta treatment of multiple sclerosis: a case report and focused literature review

OBJECTIVES

To report a rare case of sarcoidosis induced by chronic interferon-beta (a type I interferon) therapy of multiple sclerosis and to review previously reported cases.

METHODS

We describe a patient with a prior diagnosis of multiple sclerosis, who developed noncaseating granulomas in her skin and pulmonary lymph nodes, consistent with sarcoidosis, while being treated with recombinant interferon-beta. A retrospective review of the literature was performed using the PubMed database.

RESULTS

In our patient, sarcoidosis developed after 3 years of continuous recombinant interferon-beta therapy, dosed 3 times a week. The patient presented with progressive dyspnea on exertion, diffuse arthralgias, low-grade fevers, with an acute onset of rash. The diagnosis of sarcoidosis was secured by finding typical, well-formed, noncaseating granulomas on skin and endobronchial biopsies, with other possible etiologies for granulomatous conditions excluded beforehand. Following the withdrawal of recombinant interferon-beta and a course of corticosteroids combined with disease-modifying anti-rheumatic drug therapy, the patient's clinical presentation resolved. Excluding ours, only 4 additional cases of sarcoidosis developing after interferon-beta therapy have been reported, with 2 of those cases in the context of underlying multiple sclerosis.

CONCLUSIONS

Developing sarcoidosis during treatment of multiple sclerosis with recombinant interferon-beta represents an exceedingly rare and paradoxical adverse event. The occurrence of sarcoidosis with the use of this agent is perhaps due to a dysregulation in the modulatory role played by interferon-beta (and more generally type I interferon) expression in chronic inflammation.

Revealing mammalian evolutionary relationships by comparative analysis of gene clusters

Many software tools for comparative analysis of genomic sequence data have been released in recent decades. Despite this, it remains challenging to determine evolutionary relationships in gene clusters due to their complex histories involving duplications, deletions, inversions, and conversions. One concept describing these relationships is orthology. Orthologs derive from a common ancestor by speciation, in contrast to paralogs, which derive from duplication. Discriminating orthologs from paralogs is a necessary step in most multispecies sequence analyses, but doing so accurately is impeded by the occurrence of gene conversion events. We propose a refined method of orthology assignment based on two paradigms for interpreting its definition: by genomic context or by sequence content. X-orthology (based on context) traces orthology resulting from speciation and duplication only, while N-orthology (based on content) includes the influence of conversion events. We developed a computational method for automatically mapping both types of orthology on a per-nucleotide basis in gene cluster regions studied by comparative sequencing, and we make this mapping accessible by visualizing the output. All of these steps are incorporated into our newly extended CHAP 2 package. We evaluate our method using both simulated data and real gene clusters (including the well-characterized α-globin and β-globin clusters). We also illustrate use of CHAP 2 by analyzing four more loci: CCL (chemokine ligand), IFN (interferon), CYP2abf (part of cytochrome P450 family 2), and KIR (killer cell immunoglobulin-like receptors). These new methods facilitate and extend our understanding of evolution at these and other loci by adding automated accurate evolutionary inference to the biologist's toolkit. The CHAP 2 package is freely available from http://www.bx.psu.edu/miller_lab.

Conversion events in gene clusters

BACKGROUND

Gene clusters containing multiple similar genomic regions in close proximity are of great interest for biomedical studies because of their associations with inherited diseases. However, such regions are difficult to analyze due to their structural complexity and their complicated evolutionary histories, reflecting a variety of large-scale mutational events. In particular, conversion events can mislead inferences about the relationships among these regions, as traced by traditional methods such as construction of phylogenetic trees or multi-species alignments.

RESULTS

To correct the distorted information generated by such methods, we have developed an automated pipeline called CHAP (Cluster History Analysis Package) for detecting conversion events. We used this pipeline to analyze the conversion events that affected two well-studied gene clusters (α-globin and β-globin) and three gene clusters for which comparative sequence data were generated from seven primate species: CCL (chemokine ligand), IFN (interferon), and CYP2abf (part of cytochrome P450 family 2). CHAP is freely available at http://www.bx.psu.edu/miller_lab.

CONCLUSIONS

These studies reveal the value of characterizing conversion events in the context of studying gene clusters in complex genomes.

Interferon-alpha Induced Sarcoidosis with Cutaneous Involvement along the Lines of Venous Drainage

Sarcoidosis is a systemic inflammatory disease of an unknown origin and it is characterized by the presence of noncaseating epitheloid cell granulomas in multiple organs. Herein we report on a case of cutaneous and pulmonary sarcoidosis that was associated with interferon alpha treatment for hepatitis C. A 39-year-old man, a former intravenous drug user, presented with several erythematous papules on both antecubital areas. The histopathologic finding of a skin biopsy showed noncaseating granuloma. The mediastinal and axillary lymph nodes were enlarged on chest X-ray and computed tomography. To the best of our knowledge, this is the first report of cutaneous and pulmonary sarcoidosis that was associated with interferon treatment in the Korean dermatologic literature.

Sarcoidosis induced by interferon-α in melanoma patients: incidence, clinical manifestations, and management strategies

Treatment with interferon-α has been recommended for patients with melanoma in case of micrometastases, or high risk melanoma, for example, ulcerated melanoma. Furthermore, regular dermatologic examination and regular imaging to detect recurrence or progression of disease is part of the management of melanoma patients. Sarcoidosis has been described as an adverse effect of treatment with interferon-α. Especially in hepatitis C patients, there is a series of case reports on sarcoidosis induced by interferon treatment whereas in melanoma this has rarely been reported. In a retrospective study, all melanoma patients treated with interferon-α at our hospital between 2007 and 2009 were screened for occurrence of sarcoidosis. Three of 16 melanoma patients treated with interferon-α (19%) presented with sarcoidosis. All 3 patients showed lesions with higher uptake in the positron emission tomography-computed tomography scan leading to the differential diagnosis of melanoma metastases or inflammation. Skin lesions were present in 1 patient. Diagnosis was confirmed by histologic assessment of lesions showing epithelioid granuloma-negative on Ziehl Neelson. Additional work-up included blood and urinalysis, electrocardiography, and ophthalmologic examination. Cessation of interferon-α led to regression of granulomas. Sarcoidosis induced by interferon-α in melanoma patients could be more common than previously thought. This is an important complication to be aware of as it can be mistaken for metastatic spread of melanoma and thus lead to incorrect therapy.

[Sarcoidosis and genetics]

Familial features of sarcoidosis and observations in monozygotic twins affected by the condition suggest the presence of a genetic predisposition. Various genetic associations have been described with genes coding for proteins involved in immune regulation in particular at the level of interaction between T-lymphocyte and antigen presenting cell. We review the various genetic targets described with techniques ranging from classic human lymphocyte antigen genotype to genome wide linkage scans. The 6p21 region has been highlighted, which includes relevant genes such as MHC class II, BTNL2 and TNFα. These studies show that the genetics of sarcoidosis are complex, that patient sub-groups exist, which may explain some of the heterogeneity in the results of genetic studies and that the interactions between genetic and environmental factors remains to be elucidated.

Genetic epidemiology of tuberculosis susceptibility: impact of study design

Several candidate gene studies have provided evidence for a role of host genetics in susceptibility to tuberculosis (TB). However, the results of these studies have been very inconsistent, even within a study population. Here, we review the design of these studies from a genetic epidemiological perspective, illustrating important differences in phenotype definition in both cases and controls, consideration of latent M. tuberculosis infection versus active TB disease, population genetic factors such as population substructure and linkage disequilibrium, polymorphism selection, and potential global differences in M. tuberculosis strain. These considerable differences between studies should be accounted for when examining the current literature. Recommendations are made for future studies to further clarify the host genetics of TB.

Cystic fibrosis conductance regulator, tumor necrosis factor, interferon alpha-10, interferon alpha-17, and interferon gamma genotyping as potential risk markers in pulmonary sarcoidosis pathogenesis in Greek patients

Sarcoidosis is a complex disease with autoimmune basis and still unknown etiology. We have screened for mutations in the cystic fibrosis conductance regulator (CFTR) gene and genotyped single-nucleotide polymorphisms in the tumor necrosis factor (TNF), interferon alpha-10 (IFNA10), IFNA17, and interferon gamma (IFNG) genes in 89 Greek patients with sarcoidosis and 212 control subjects to detect possible association between them and the risk for developing sarcoidosis. We have found a statistically significant increase (p = 6.1 x 10(-8)) of CFTR mutation carriers in the population of patients with sarcoidosis versus the control population. A difference was also noted within the group of patients with sarcoidosis where the ones with CFTR mutations suffered more frequently from dyspnea than those without (p = 5 x 10(-6)). Our study did not reproduce the associations previously noted with the TNF, IFNA10, IFNA17, and IFNG genes, which highlights the genetic complexity of the disorder and is in agreement with previous studies showing that CFTR might be an important factor in the clinical course of the disease.

Tuberculosis as a complex trait: impact of genetic epidemiological study design

Several studies have suggested a role for human genetic risk factors in the susceptibility to developing tuberculosis (TB). However, results of these studies have been inconsistent, and one potential reason for these inconsistencies is variation in aspects of study design. Specifically, phenotype definitions and population genetic factors have varied dramatically. Since TB is a complex trait, there are many challenges in designing studies to assess appropriately human genetic risk factors for the development of TB as opposed to the acquisition of latent M. tuberculosis infection. In this review we summarize these important study design differences, with illustrations from the TB genetics literature. We cite specific examples of studies of the NRAMP1 (SLC11A1) gene and present Fisher's combined p values for different stratifications of these studies to further illustrate the impact of study design differences. Finally, we provide suggestions for the design of future genetic epidemiological studies of TB.

Sarcoidosis and hepatitis C: clinical description of 11 cases

BASIC: To describe the main characteristics and treatment of sarcoidosis in patients with chronic hepatitis C virus (HCV) infection.

METHODS

Retrospective cohort study of patients with chronic HCV infection and sarcoidosis at our tertiary institution.

RESULTS

Eleven cases (eight women, three men) fulfilled the criteria for sarcoidosis. Four cases belong to our population of 3194 (0.12%) HCV patients seen in our department between 2001 and 2008. In five cases, sarcoidosis was triggered by antiviral therapy (consisted of interferon-alpha monotherapy in one case and combined therapy with interferon-alpha and ribavirin in four cases) and developed from 23 to 82 months after completion of therapy in three cases. For these patients, pulmonary adenopathies were found in three patients while two presented cutaneous involvement, one had uveitis and one presented both arthritis and extrapulmonary lymphadenopathies. Two patients received systemic corticosteroids with a favourable outcome. Four treatment-naive patients developed sarcoidosis. Two had pulmonary disease, one had medullar involvement, one had superficial lymphadenopathy and one had arthralgia. Three patients received systemic corticosteroids with chronic outcome in all cases. One of the two patients with an earlier history of sarcoidosis experienced a benign relapse that resolved spontaneously.

CONCLUSION

Clinical manifestations of sarcoidosis may occur in HCV patients, especially during or after treatment with immunotherapy. In our experience, sarcoidosis triggered by antiviral therapy was more frequent after completion of therapy, but concording with literature, presented a benign outcome. In sarcoidosis, seen in treatment-naive HCV patients, systemic corticosteroids had to be used more often and outcome was less favourable.

Analysis of eight genes modulating interferon gamma and human genetic susceptibility to tuberculosis: a case-control association study

Background

Interferon gamma is a major macrophage-activating cytokine during infection with Mycobacterium tuberculosis, the causative pathogen of tuberculosis, and its role has been well established in animal models and in humans. This cytokine is produced by activated T helper 1 cells, which can best deal with intracellular pathogens such as M. tuberculosis. Based on the hypothesis that genes which regulate interferon gamma may influence tuberculosis susceptibility, we investigated polymorphisms in eight candidate genes.

Methods

Fifty-four polymorphisms in eight candidate genes were genotyped in over 800 tuberculosis cases and healthy controls in a population-based case-control association study in a South African population. Genotyping methods used included the SNPlex Genotyping System™, capillary electrophoresis of fluorescently labelled PCR products, TaqMan^® SNP genotyping assays or the amplification mutation refraction system. Single polymorphisms as well as haplotypes of the variants were tested for association with TB using statistical analyses.

Results

A haplotype in interleukin 12B was nominally associated with tuberculosis (p = 0.02), but after permutation testing, done to assess the significance for the entire analysis, this was not globally significant. In addition a novel allele was found for the interleukin 12B D5S2941 microsatellite.

Conclusions

This study highlights the importance of using larger sample sizes when attempting validation of previously reported genetic associations. Initial studies may be false positives or may propose a stronger genetic effect than subsequently found to be the case.

Past, present and future directions in human genetic susceptibility to tuberculosis

The historical impression that tuberculosis was an inherited disorder has come full circle and substantial evidence now exists of the human genetic contribution to susceptibility to tuberculosis. This evidence has come from several whole-genome linkage scans, and numerous case-control association studies where the candidate genes were derived from the genome screens, animal models and hypotheses pertaining to the disease pathways. Although many of the associated genes have not been validated in all studies, the list of those that have been is growing, and includes NRAMP1, IFNG, NOS2A, MBL, VDR and some TLR. Certain of these genes have consistently been associated with tuberculosis in diverse populations. The future investigation of susceptibility to tuberculosis is almost certain to include genome-wide association studies, admixture mapping and the search for rare variants and epigenetic mechanisms. The genetic identification of more vulnerable individuals is expected to inform personalized treatment and perhaps vaccination strategies.

Dendritic cells in the pathogenesis of sarcoidosis

Sarcoidosis is a noncaseating granulomatous disease, likely of autoimmune etiology, that causes inflammation and tissue damage in multiple organs, most commonly the lung, but also skin, and lymph nodes. Reduced dendritic cell (DC) function in sarcoidosis peripheral blood compared with peripheral blood from control subjects suggests that blunted end organ cellular immunity may contribute to sarcoidosis pathogenesis. Successful treatment of sarcoidosis with tumor necrosis factor (TNF) inhibitors, which modulate DC maturation and migration, has also been reported. Together, these observations suggest that DCs may be important mediators of sarcoidosis immunology. This review focuses on the phenotype and function of DCs in the lung, skin, blood, and lymph node of patients with sarcoidosis. We conclude that DCs in end organs are phenotypically and functionally immature (anergic), while DCs in the lymph node are mature and polarize pathogenic Th1 T cells. The success of TNF inhibitors is thus likely secondary to inhibition of DC-mediated Th1 polarization in the lymph node.

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.

Genetic association of interferon-alpha subtypes 1, 2 and 5 in systemic lupus erythematosus

In this study, the association between the systemic lupus erythematosus (SLE) susceptibility and the new candidate genes, IFNA1, IFNA2 and IFNA5 genes, major interferon-alpha subtypes, in responses to viral infection was investigated. Allele and genotype frequencies of each marker were compared between 150 SLE patients and 150 healthy control subjects. This study indicated that the A/A genotype of IFNA5 (-2529) and the G/G genotype of IFNA1 (-1823) were associated with the protection of SLE disease in a recessive model [P(c) = 0.03, P = 0.01, odds ratio (OR) = 0.4, 95% confidence interval (CI) = 0.2-0.8 and P(c) = 0.09, P = 0.03, OR = 0.5, 95% CI = 0.2-0.9, respectively). Multifactor dimensionality reduction analysis showed a marginal interaction between IFNA5 (-2529) and IFNA1 (-1823) gene, with a cross-validation consistency of 10 of 10 and a prediction error of 46% (permutation P-value = 0.05). This is the first report of positive association of IFNA gene in SLE, especially the role of specific subtypes IFNA1 and IFNA5.

Promoter polymorphisms in the IRF3 gene confer protection against systemic lupus erythematosus

In order to identify a novel candidate gene in systemic lupus erythematosus (SLE), we analysed a panel of six genes encoding molecules involved in the type I interferon (IFN) system. We first identified variants in the five genes related to type I IFN pathway by sequencing. Genotyping of a panel of eight selected single-nucleotide polymorphisms (SNPs) in six candidate genes ( TLR9, MYD88, IRF3, IRF7, IFNB1, IFNA17) was performed in 137 patients with SLE and matched with 152 healthy controls using polymerase chain reaction-restriction fragment length polymorphism analysis. In functional assay, quantitative real-time polymerase chain reaction was performed to assess constitutive IRF3 mRNA expression in peripheral blood mononuclear cells from healthy subjects with different IRF3 promoter haplotypes. Among eight SNPs genotyped, an IRF3 SNP at –925 was found to be associated with SLE after correction for multiple tests (corrected P = 0.016). Of total five IRF3 SNPs genotyped, the promoter IRF3 SNPs –925A/G and –776C/T showed the most significant association with SLE. With regard to –925A/G, the frequency of GG genotype was significantly decreased among SLE patients compared with the control group (1.5% vs. 9.9%; χ2 = 10.0, P = 0.0015, odds ratio 0.12, 95% confidence interval 0.027–0.554). Our experimental data indicated that constitutive IRF3 mRNA expression was significantly lower in cells carrying the minor G-T/G-T haplotype pair compared with those carrying the major A-C haplotype. In conclusion, we showed that the promoter SNPs of the IRF3 gene were significantly associated with resistance against SLE.

Mutation screening of the CARD15 gene in sarcoidosis

CARD15 was first identified as a susceptibility gene for Crohn's disease. More recently, CARD15 mutations were shown to be associated with the pediatric granulomatous inflammatory diseases, Blau syndrome and early-onset sarcoidosis (EOS). The aim of the present study was to evaluate whether CARD15 variants also play a role in patients with ordinary sarcoidosis other than EOS. We enrolled 135 Japanese sarcoidosis patients with uveitis as well as 95 healthy individuals and performed mutation analysis by direct sequencing of CARD15 exon 4. Direct DNA sequencing in the sarcoidosis patients showed eight CARD15 variants, including five novel mutations (13402C>T, 13543C>T, 13775C>A, 13937G>A, and 14079C>T). Compared with healthy individuals, CARD15 mutations are not common in the Japanese patients with sarcoidosis. Based on the results, we examined the clinical manifestations in patients with sarcoidosis according to their CARD15 mutations. Sarcoidosis patients with these mutations have no specific clinical features with regard to course of the disease or disease severity. Our results indicate that in general, CARD15 mutations may not contribute to the risk of sarcoidosis.

Genetic predisposition to respiratory diseases: infiltrative lung diseases

The availability of high-throughput genotyping and large collaborative clinical networks creating well-characterized patient populations with DNA repositories has facilitated genome-wide scans and candidate gene studies to identify susceptibility alleles for the development of interstitial lung disease. The association of pulmonary fibrosis with rare inherited disorders, and the variable susceptibility of inbred mouse strains to this disease indicate that pulmonary fibrosis is determined by genetic factors. Sarcoidosis represents a complex disease with racial and ethnic differences in disease prevalence, and evidence of familial clustering. Familial aggregation of sarcoidosis from 'A Case-Control Etiologic Study of Sarcoidosis' (ACCESS) reveals a familial odds ratio (OR) of sarcoidosis of 5.8 (95% CI 2.1-15.9) for sibs and 3.8 (95% CI 1.2-11.3) for parents. Several HLA class II alleles have been associated with either increased or decreased risk of sarcoidosis, and results vary depending on study populations of different ethnicity. Genome-wide screening has conclusively identified linkage to chromosome 5q11and the development of sarcoidosis, and HLA genes and BTNL2 are susceptibility genes located in this region. Familial aggregation of idiopathic interstitial pneumonia (IIP) has been established by several groups, and a large US-based study suggests autosomal dominant inheritance with reduced penetrance; furthermore, cigarette smoking was associated with affection status among siblings (OR = 3.6, 95% CI 1.3-9.8, p = 0.01). Families demonstrate more than one type of IIP, suggesting various subtypes of IIP may share a common pathogenesis. Genome-wide linkage scans in familial interstitial pneumonia demonstrate linkage to chromosomes 4, 5 and 11. Candidate gene studies indicate that surfactant protein C and telomerase are susceptibility genes for the development of pulmonary fibrosis. Future challenges include determining how multiple susceptibility alleles interact with each other and environmental factors resulting in disease risk and multiple phenotypes, and determining the mechanism of action and cellular pathways involving susceptibility alleles. Further insight into these areas may lead to new therapeutic interventions.

Expression patterns and action analysis of genes associated with inflammatory responses during rat liver regeneration

AIM: To study the relationship between inflammatory response and liver regeneration (LR) at transcriptional level.

METHODS: After partial hepatectomy (PH) of rats, the genes associated with inflammatory response were obtained according to the databases, and the gene expression changes during LR were checked by the Rat Genome 230 2.0 array.

RESULTS: Two hundred and thirty-nine genes were associated with liver regeneration. The initial and total expressing gene numbers found in initiation phase (0.5-4 h after PH), G₀/G₁ transition (4-6 h after PH), cell proliferation (6-66 h after PH), cell differentiation and structure-function reconstruction (66-168 h after PH) of liver regeneration were 107, 34, 126, 6 and 107, 92, 233, 145 respectively, showing that the associated genes were mainly triggered at the beginning of liver regeneration, and worked at different phases. According to their expression similarity, these genes were classified into 5 groups: only up-regulated, predominantly up-, only down-, predominantly down-, up- and down-, involving 92, 25, 77, 14 and 31 genes, respectively. The total times of their up- and down-regulated expression were 975 and 494, respectively, demonstrating that the expressions of the majority of genes were increased, and that of a few genes were decreased. Their time relevance was classified into 13 groups, showing that the cellular physiological and biochemical activities were staggered during liver regeneration. According to gene expression patterns, they were classified into 33 types, suggesting that the activities were diverse and complex during liver regeneration.

CONCLUSION: Inflammatory response is closely associated with liver regeneration, in which 239 LR-associated genes play an important role.

Genetics of sarcoidosis: candidate genes and genome scans

Human leukocyte antigen class II allele associations and T-cell receptor beta chain bias in sarcoidosis suggest a specific disease-triggering antigen exposure in a genetically susceptible host. The cause of sarcoidosis has been elusive, but genetics provides one of the few promising avenues to further our understanding. We review the association studies and genome scans used to identify the genes involved in sarcoidosis.

Interferon therapy for ocular disease

PURPOSE OF REVIEW

Interferons were first known for their antiviral action. Immunomodulatory therapy with interferons has been studied in various diseases. This paper summarizes the role and presumed mechanisms of action of type 1 interferons in the treatment of ocular disease.

RECENT FINDINGS

Preliminary data show beneficial effects of interferons in ocular disease such as Behçet disease and multiple sclerosis-associated uveitis in terms of visual acuity, intraocular inflammation activity, and chronic macular edema. Another mode of application is topical as an adjuvant treatment in viral keratitis or ocular surface malignancies.

SUMMARY

Interferons are gaining a place in the treatment of ocular disease. Evidence is growing of their potential in ocular Behçet disease and multiple sclerosis-associated uveitis. Randomized, controlled clinical trials are needed to confirm this observation. Further insights into the complex mechanisms of action of interferons in health and disease will increase understanding of their mechanisms of action as a therapeutic substance.

Interferon-Induced Sarcoidosis

Rheumatologists are increasingly asked to see patients with hepatitis C who exhibit a variety of clinical and serologic features that mimic systemic rheumatic disease. Treatment with interferons, now the standard of care, can precipitate a variety of inflammatory conditions, including sarcoidosis. We present a case of a 59-year-old former intravenous drug user who developed systemic sarcoidosis while receiving interferon alpha and ribavirin for the treatment of chronic hepatitis C. Because interferons are increasingly prescribed by specialists in a variety of disciplines, rheumatologists should be aware of their potential to induce sarcoidosis as well as various autoimmune diseases.

Integrating systems biology and medical imaging: understanding disease distribution in the lung model

OBJECTIVE

Many chronic diseases exhibit characteristic pulmonary distribution patterns, but the underlying biologic explanations remain elusive. On the basis of emerging evidence from systems biology, we propose that gradients of T helper immune function exist as an epiphenomenon of the hypoxic pulmonary vasoconstriction response. Regional variation of immune function may contribute to preferential distribution patterning of lung diseases.

CONCLUSION

The lungs represent but one example in which the distribution of immune function throughout the body may explain disease location. This hypothetic framework can apply to diseases outside the realm of pulmonary biology and illustrates the potential benefit of integrating advances in systems biology and medical imaging.

Sarcoidosis after treatment with interferon-alpha: a case series and review of the literature

Recombinant interferon-alpha (rINF-alpha) is an immunomodulator used in the treatment of various conditions, including viral infections and malignancies. The use of rINF-alpha has been associated with the development of sarcoidosis in recent case reports. In this series, we report the incidence of sarcoidosis in recipients of rINF-alpha for hepatitis C viral (HCV) infection at our institution. We also review the 57 additional cases of sarcoidosis associated with rINF-alpha described in the literature, including clinical presentation, radiographic findings, management, and outcomes, and discuss the potential mechanisms by which rINF-alpha may lead to the development of sarcoidosis.

Variation in the type I interferon gene cluster on 9p21 influences susceptibility to asthma and atopy

A genome-wide screen for asthma and atopy susceptibility alleles conducted in the Hutterites, a founder population of European descent, reported evidence of linkage with a short tandem repeat polymorphism (STRP) within the type I interferon (IFN) gene cluster on chromosome 9p21. The goal of this study was to identify variation within the IFN gene cluster that influences susceptibility to asthma and atopic phenotypes. We screened approximately 25 kb of sequence, including the flanking sequence of all 15 functional genes and the single coding exon in 12, in Hutterites representing different IFNA-STRP genotypes. We identified 78 polymorphisms, and genotyped 40 of these (in 14 genes) in a large Hutterite pedigree. Modest associations (0.003<P<0.05) with asthma, bronchial hyper-responsiveness (BHR), and atopy were observed with individual variants or genes, spanning the entire 400 kb region. However, pairwise combinations of haplotypes between genes showed highly significant associations with different phenotypes (P<10(-5)) that were localized to specific pairs of genes or regions of this cluster. These results suggest that variation in multiple genes in the type I IFN cluster on 9p22 contribute to asthma and atopy susceptibility, and that not all genes contribute equally to all phenotypes.