New data in causes of autoinflammatory diseases

A mathematical model of Familial Mediterranean Fever predicts mechanisms controlling inflammation

BACKGROUND

Familial Mediterranean Fever (FMF) is a monogenic disease caused by gain-of-function mutations in the MEditerranean FeVer (MEFV) gene. The molecular dysregulations induced by these mutations and the associated causal mechanisms are complex and intricate.

OBJECTIVE

We sought to provide a computational model capturing the mechanistic details of biological pathways involved in FMF physiopathology and enabling the study of the patient's immune cell dynamics.

METHODS

We carried out a literature survey to identify experimental studies published from January 2000 to December 2020, and integrated its results into a molecular map and a mathematical model. Then, we studied the network of molecular interactions and the dynamic of monocytes to identify key players for inflammation phenotype in FMF patients.

RESULTS

We built a molecular map of FMF integrating in a structured manner the current knowledge regarding pathophysiological processes participating in the triggering and perpetuation of the disease flares. The mathematical model derived from the map reproduced patient's monocyte behavior, in particular its proinflammatory role via the Pyrin inflammasome activation. Network analysis and in silico experiments identified NF-κB and JAK1/TYK2 as critical to modulate IL-1β- and IL-18-mediated inflammation.

CONCLUSION

The in silico model of FMF monocyte proved its ability to reproduce in vitro observations. Considering the difficulties related to experimental settings and financial investments to test combinations of stimuli/perturbation in vitro, this model could be used to test complex hypotheses in silico, thus narrowing down the number of in vitro and ex vivo experiments to perform.

TNFAIP3 mutation causing haploinsufficiency of A20 with a hemophagocytic lymphohistiocytosis phenotype: a report of two cases

BACKGROUND

A20 haploinsufficiency (HA20) is a newly introduced autosomal dominant autoinflammatory disorder, also known as Behcet's-like disease. Some of the most common symptoms of the disease are recurrent oral, genital, and/or gastrointestinal (GI) ulcers, episodic fever, musculoskeletal symptoms, cutaneous lesions, and recurrent infections. Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening condition of multi-organ failure due to excessive immune activation. HLH has been reported in a few HA20 patients. Herein, we report two children with the primary presentation of HLH, with a mutation in TNFAIP3, in favor of HA20.

CASE PRESENTATIONS

Our first patient was a 4-month-old boy who presented with fever, irritability, pallor, and hepatosplenomegaly. Pancytopenia, elevated ferritin, and decreased fibrinogen levels were found in laboratory evaluation. He was diagnosed with HLH and was treated with methylprednisolone and cyclosporine. Two years later, whole exome sequencing (WES) indicated a mutation in TNFAIP3 at NM_001270507: exon3: c.C386T, p.T129M, consistent with A20 haploinsufficiency. Etanercept, a TNF inhibitor, was prescribed, but the parents were reluctant to initiate the therapy. The patient passed away with the clinical picture of cerebral hemorrhage. The second patient was a 3-month-old boy who presented with a fever and hepatosplenomegaly. Laboratory evaluation found pancytopenia, hyperferritinemia, hypoalbuminemia, hypertriglyceridemia, and hypofibrinogenemia. With the establishment of the HLH diagnosis, he was treated with etoposide, dexamethasone, and cyclosporine, and recovered. WES results revealed a heterozygous de novo variant of TNFAIP3 (c. T824C in exon 6, 6q23.3) that leads to a proline to leucine amino acid change (p. L275P). He was treated with etanercept and has been symptom-free afterward.

CONCLUSIONS

This report is a hypothesis for developing of the HLH phenotype in the presence of TNFAIP3 mutation. Our results provide a new perspective on the role of TNFAIP3 mutation in HLH phenotypes, but more extensive studies are required to confirm these preliminary results.

Predicting Prognosis and Distinguishing Cold and Hot Tumors in Bladder Urothelial Carcinoma Based on Necroptosis-Associated lncRNAs

Background

In reference to previous studies, necroptosis played an important role in cancer development. Our team decided to explore the potential prognostic values of long non-coding RNAs (lncRNAs) associated with necroptosis in bladder urothelial carcinoma (BLCA) and their relationship with the tumor microenvironment (TME) and the immunotherapeutic response for accurate dose.

Methods

To obtain the required data, bladder urothelial carcinoma transcriptome data were searched from Cancer Genome Atlas (TCGA) (https://portal.gdc.cancer.gov/). We used co-expression analysis, differential expression analysis, and univariate Cox regression to screen out prognostic lncRNAs associated with necroptosis in BLCA. Then the least absolute shrinkage and selection operator (LASSO) was conducted to construct the necroptosis-associated lncRNAs model. Based on this model, we also performed the Kaplan–Meier analysis and time-dependent receiver operating characteristics (ROC) to estimate the prognostic power of risk score. Multivariate and univariate Cox regression analysis were performed to build up a nomogram. Calibration curves, and time-dependent ROC were also conducted to evaluate nomogram. Principal component analysis (PCA) revealed a difference between high- and low-risk groups. In addition, we explored immune analysis, gene set enrichment analyses (GSEA), and evaluation of the half-maximal inhibitory concentration (IC50) in constructed model. Finally, the entire samples were divided into three clusters based on model of necroptosis-associated lncRNAs to further compare immunotherapy in cold and hot tumors.

Results

A model was built up based on necroptosis-associated lncRNAs. The model revealed good consistence between calibration plots and prognostic prediction. The area of 1-, 3-, and 5-year OS under the ROC curve (AUC) were 0.707, 0.679, and 0.675. Risk groups could be helpful for systemic therapy due to the markedly diverse IC50 between risk groups. To our delight, clusters could effectively identify cold and hot tumors, which would be beneficial to accurate mediation. Clusters 2 and 3 were considered the hot tumor, which was more sensitive to immunotherapeutic drugs.

Conclusions

The outcomes of our study suggested that necroptosis-associated lncRNAs could effectively predict patients with BLCA prognosis, which may be helpful for distinguishing the cold and hot tumors and improving individual treatment of BLCA.

Progress in the genetics of uveitis

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

Clinical characteristics and genetic analysis of A20 haploinsufficiency

PURPOSE

To evaluate the clinical and genetic characteristics of 3 children with Haploinsufficiency of A20 (HA20).

METHODS

The clinical and genetic testing data of 3 children with HA20 treated at Capital Institute of Pediatrics (CIP) between August 2016 and October 2019 were retrospectively analysed.

RESULT

Patient 1 presented with arthritis and inflammatory bowel disease, patient 2 presented with axial spinal arthritis and lupus-like syndrome, and patient 3 presented with recurrent oral ulcers, gastrointestinal ulcers, and perianal abscesses. Regarding laboratory tests, patients were found to have elevated white blood cell (WBC) count, C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). The CRP and ESR was reported to be high in all the patients. The WBC was reported to be high in patient 1 and 3. Patient 2 was positive for antinuclear antibodies, anti-Sjögren's syndrome antigen A, dsDNA, rheumatoid factor and Coombs test. Genetic testing showed that all three patients had heterozygous mutation in TNFAIP3 gene. As for the treatment, patient 1 was treated with TNFα antagonist, patient 2 was treated with TNF α antagonist and sulfasalazine, and patient 3 was treated with corticosteroids and thalidomide. Patients 1 and 2 were followed for four and 3 months, respectively. There was an improvement in joint and gastrointestinal symptoms; inflammatory indices and rheumatoid factor (RF) were normal, and dsDNA and Coombs test became negative. Patient 3 was treated at another hospital and showed gradual improvement in oral ulcers and perianal abscesses.

CONCLUSION

HA20 is a single-gene auto-inflammatory disease caused by mutation in tumour necrosis factor (TNF)-α-induced protein 3 (TNFAIP3) gene. It may present as Behçet-like syndrome and resemble various other autoimmune diseases as well. Corticosteroids and immunosuppressive agents are effective treatments, and cytokine antagonists can be used in refractory cases. Whole-exome genetic testing should be proactively performed for children with early-age onset or Behçet-like syndrome to achieve early diagnosis and accurate treatment.

French recommendations for the management of Behçet's disease

Behçet's disease (BD) is a systemic variable vessel vasculitis that involves the skin, mucosa, joints, eyes, arteries, veins, nervous system and gastrointestinal system, presenting with remissions and exacerbations. It is a multifactorial disease, and several triggering factors including oral cavity infections and viruses may induce inflammatory attacks in genetically susceptible individuals. BD vasculitis involves different vessel types and sizes of the vascular tree with mixed-cellular perivascular infiltrates and is often complicated by recurrent thrombosis, particularly in the venous compartment. Several new therapeutic modalities with different mechanisms of action have been studied in patients with BD. A substantial amount of new data have been published on the management of BD, especially with biologics, over the last years. These important therapeutic advances in BD have led us to propose French recommendations for the management of Behçet's disease [Protocole National de Diagnostic et de Soins de la maladie de Behçet (PNDS)]. These recommendations are divided into two parts: (1) the diagnostic process and initial assessment; (2) the therapeutic management. Thirty key points summarize the essence of the recommendations. We highlighted the main differential diagnosis of BD according to the type of clinical involvement; the role of genetics is also discussed, and we indicate the clinical presentations that must lead to the search for a genetic cause.

Association of Behçet disease with psoriasis and psoriatic arthritis

Behçet disease (BD) is a debilitating multi-systemic vasculitis with a litany of muco-cutaneous manifestations and potentially lethal complications. Meanwhile, psoriasis (PSO) is a cutaneous and systemic inflammatory disorder marked by hyperplastic epidermis and silvery scales, which may be accompanied by a distinct form of arthropathy called psoriatic arthritis (PsA). While the clinical pictures of these two are quite different, they feature some important similarities, most of which may stem from the autoinflammatory components of BD and PSO. Therefore, the aim of this study was to investigate the prospective link between BD and cutaneous and articular manifestations of psoriasis. BD, PSO, and PsA cohorts were extracted using the National Health Insurance Service of Korea database. Using χ² tests, prevalence of PSO and PsA with respect to BD status was analysed. Relative to non-BD individuals, those with personal history of BD were nearly three times more likely to be diagnosed with PSO. The adjusted odds ratio (aOR) was 2.36 [95% confidence interval (CI), 1.91–2.93, p < 0.001]. Elevated PSO risk was more pronounced in the male BD cohort (aOR = 1.19, 95% CI 1.16–1.23, p < 0.001). In age-group sub-analysis, individuals over 65 years with PSO were one and a half times more likely to be affected with BD, relative to those under 65. The adjusted OR for the older group was 1.51 (95% CI 1.43–1.59, p < 0.001). BD individuals with “healthy” body weight were significantly less likely to be affected by PSO (aOR = 0.59, 95% CI 0.57–0.62, p < 0.001). On the other hand, there was a correlation between BMI and the risk of BD, with the “moderately obese (30–35 kg/m²)” group having an aOR of 1.24 (95% CI 1.12–1.38, p < 0.001). BD patients were also twice more likely to be associated with PsA (aOR = 2.19, 95% CI 1.42–3.38, p < 0.001). However, in contrast to the case of psoriatic disease itself, females were exposed to a greater risk of developing BD compared to the male PsA cohort (aOR = 2.02, 95% CI 1.88–2.16, p < 0.001). As with PSO, older BD patients were exposed to a significantly higher risk of developing PsA (aOR = 3.13, 95% CI 2.90–3.40, p < 0.001). Behçet disease may place an individual at a significantly increased risk of psoriasis, and still greater hazard of being affected with psoriatic arthritis. This added risk was pronounced in the male cohort, and tended to impact senile population, and this phenomenon may be related with the relatively poor prognosis of BD in males and PSO in older patients.

Whole-Exome Sequencing of Patients With Posterior Segment Uveitis

OBJECTIVE

To elucidate molecular risk factors for posterior segment uveitis using a functional genomics approach.

DESIGN

Genetic association cohort study.

METHODS

Setting: Single-center study at an academic referral center.

STUDY POPULATION

164 patients with clinically diagnosed uveitis of the posterior segment.

MAIN OUTCOME MEASURES

Exome sequencing was used to detect variants identified in 164 patients with posterior segment uveitis. A phenotype-driven analysis, protein structural modeling, and in silico calculations were then used to rank and predict the functional consequences of key variants.

RESULTS

A total of 203 single nucleotide variants, in 23 genes across 164 patients, were included in this study. Both known and novel variants were identified in genes previously implicated in specific types of syndromic uveitis-such as NOD2 (Blau syndrome) and CAPN5 NIV (neovascular inflammatory vitreoretinopathy)-as well as variants in genes not previously linked to posterior segment uveitis. Based on a ranked list and protein-protein-interaction network, missense variants in NOD-like receptor family genes (NOD2, NLRC4, NLRP3, and NLRP1), CAPN5, and TYK2 were characterized via structural modeling and in silico calculations to predict how specific variants might alter protein structure and function. The majority of analyzed variants were notably different from wild type.

CONCLUSIONS

This study implicates new pathways and immune signaling proteins that may be associated with posterior segment uveitis susceptibility. A larger cohort and functional studies will help validate the pathogenicity of the mutations identified. In specific cases, whole-exome sequencing can help diagnose nonsyndromic uveitis in patients harboring known variants for syndromic inflammatory diseases.

Cutaneous clues to diagnose autoinflammatory diseases

Systemic autoinflammatory diseases (AIDs) are a group of disorders characterized by recurrent episodes of systemic inflammation. Suspecting the diagnosis can be difficult and many of the clinical manifestations are common to different diseases. Although most of the cutaneous manifestations are non-specific, it is important to know them because sometimes they can lead to the diagnosis. The purpose of this review was to synthesize the main cutaneous lesions of autoinflammatory diseases to aid in their diagnosis.

Phenotype variability of autoinflammatory disorders in the pediatric patient: A pictorial overview

Disruption of innate immunity leading to systemic inflammation and multi-organ dysfunction is the basilar footprint of autoinflammatory disorders (AIDs), ranging from rare hereditary monogenic diseases to a large number of common chronic inflammatory conditions in which there is a simultaneous participation of multiple genetic components and environmental factors, sometimes combined with autoimmune phenomena and immunodeficiency. Whatever their molecular mechanism, hereditary AIDs are caused by mutations in regulatory molecules or sensors proteins leading to dysregulated production of proinflammatory cytokines or cytokine-inducing transcription factors, fever, elevation of acute phase reactants, and a portfolio of manifold inflammatory signs which might occur in a stereotyped manner, mostly with overactivity or misactivation of different inflammasomes. Symptoms might overlap in the pediatric patient, obscuring the final diagnosis of AIDs and delaying the most appropriate treatment. Actually, the fast-paced evolution of scientific knowledge has led to recognize or reclassify an overgrowing number of multifactorial diseases, which share the basic pathogenetic mechanisms with AIDs. The wide framework of classic hereditary periodic fevers, AIDs with prominent skin involvement, disorders of the ubiquitin-proteasome system, defects of actin cytoskeleton dynamics, and also idiopathic nonhereditary febrile syndromes occurring in children is herein presented. Interleukin-1 dependence of these diseases or involvement of other predominating molecules is also discussed.

The Influence of Adalimumab and Cyclosporine A on the Expression Profile of the Genes Related to TGFβ Signaling Pathways in Keratinocyte Cells Treated with Lipopolysaccharide A

BACKGROUND

In the treatment of moderate to severe psoriasis, cyclosporine A (CsA) conventional therapy is used and biological, anti-cytokine treatment using, for example, anti-TNF drug-adalimumab.

AIM

This study aimed at investigating the effect of CsA and adalimumab on the profile of mRNAs and protein expression associated with transforming growth factor β (TGFβ) pathways in human keratinocyte (HaCaT) culture previously exposed to lipopolysaccharide (LPS).

MATERIALS AND METHODS

HaCaT culture was exposed to 1 ng/ml LPS for 8 hours+8 μg/ml adalimumab for 2, 8, and 24 hours or 1 ng/ml LPS for 8 hours+100 ng/ml CsA for 2, 8, and 24 hours and compared to the control culture. Sulphorodamine B cytotoxicity assay was performed. The expression profile of mRNA related to TGFβ paths was indicated by microarray and RTqPCR analyses. The ELISA test was used to analyze changes on the proteome level. Statistical analysis consisted of ANOVA analysis and the post hoc Tukey test (p < 0.05).

RESULTS

The cytotoxicity test showed that LPS, adalimumab, and cyclosporine in the concentration used in this experiment did not have any cytotoxicity effect on HaCaT cells. The largest fold changes (FC) in expression in (∣FC | >4.00) was determined for TGFβ1-3, TGFβRI-III, SKIL, SMURF2, SMAD3, BMP2, BMP6, JAK2, UBE2D1, SKP2, EDN1, and PRKAR2B (p < 0.05). In addition, on the protein level, the direct changes observed at mRNA were the same.

CONCLUSION

Analysis of the microarray expression profile of genes associated with TGFβ signaling pathways has demonstrated the potential of cyclosporin A and adalimumab to induce changes in their transcriptional activity. The anti-TNF drug seems to affect TGFβ cascades to a greater extent than cyclosporin A. The obtained results suggest that the regularity of taking the drug is important for the efficacy of psoriasis therapy.

Juvenile-onset Behçet's syndrome and mimics

Behçet's syndrome (BS) presents in childhood in up to 20% of reported cases. Diagnosis is clinical and multiple classification criteria have been developed. Presentation is heterogenous with recurrent oral ulceration often being the presenting feature. Mucocutaneous disease including genital ulceration and skin involvement is a common phenotype. Vascular and neurological manifestations are rarer, particularly in childhood. Musculoskeletal and gastro-intestinal involvement which do not form part of commonly used classification criteria, appear more frequent in children. Treatment approaches are extrapolated from studies of adult onset disease. The pathogenesis of BS is not well defined although dysregulation in both innate and adaptive immune systems, together with abnormal antigen presentation have been described. The recent discovery of monogenic mimics of BS requires further genetic studies to understand the burden of monogenic autoinflammatory conditions affecting those with a BS phenotype.

Tenuifolin Attenuates Amyloid-β42-Induced Neuroinflammation in Microglia Through the NF-κB Signaling Pathway

BACKGROUND

Inflammation and oxidative stress are believed to play an important role in the pathogenesis of Alzheimer's disease (AD). Tenuifolin (TEN) is a natural neuroprotective compound extracted from Polygala tenuifolia Willd, which may improve cognitive symptoms.

OBJECTIVE

This study was designed to evaluate the protective effect of TEN on inflammatory and oxidative stress induced by amyloid-β (Aβ)42 oligomers in BV2 cells, and to explore the underlying mechanisms.

METHODS

We conducted cell viability assays to estimate drug toxicity and drug effects on cells. Quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assays were performed to detect the release of inflammatory factors. Nitric oxide (NO) assays were used to measure the degree of oxidative stress. Western blot and immunofluorescence analysis were used to explore the influence of TEN on the nuclear factor-κB (NF-κB) pathway.

RESULTS

Pretreatment of BV2 microglial cells with TEN inhibited the release of tumor necrosis factor-α, interleukin-6, and interleukin-1β, alleviated NO-induced oxidative stress by inhibiting the expression of inducible nitric oxide synthase and cyclo-oxygenase-2, and protected SH-SY5Y cells from the toxicity induced by the medium conditioned by BV2 cells previously exposed to Aβ42 oligomers. Moreover, TEN suppressed upstream activators of NF-κB, as well as NF-κB translocation to the nucleus in BV2 microglial cells.

CONCLUSION

This study demonstrates that TEN can protect SH-SY5Y cells from Aβ42 oligomer-induced microglia-mediated inflammation, and oxidative stress by downregulating the NF-κB signaling pathway.

Lipodystrophic syndromes: From diagnosis to treatment

Lipodystrophic syndromes are acquired or genetic rare diseases, characterised by a generalised or partial lack of adipose tissue leading to metabolic alterations linked to strong insulin resistance. They encompass a variety of clinical entities due to primary defects in adipose differentiation, in the structure and/or regulation of the adipocyte lipid droplet, or due to immune-inflammatory aggressions, chromatin deregulations and/or mitochondrial dysfunctions affecting adipose tissue. Diagnosis is based on clinical examination, pathological context and comorbidities, and on results of metabolic investigations and genetic analyses, which together determine management and genetic counselling. Early lifestyle and dietary measures focusing on regular physical activity and avoiding excess energy intake are crucial. They are accompanied by multidisciplinary follow-up adapted to each clinical form. In case of hyperglycemia, antidiabetic medications, with metformin as a first-line therapy in adults, are used in addition to lifestyle and dietary modifications. When standard treatments have failed to control metabolic disorders, the orphan drug metreleptin, an analog of leptin, can be effective in certain forms of lipodystrophy syndrome. Metreleptin therapy indications, prescription and monitoring were recently defined in France, representing a major improvement in patient care.

Early administration of adalimumab for paediatric uveitis due to Behçet's disease

BACKGROUND

Behçet's disease is a chronic inflammatory multisystem disorder that is characterised by oral and/or genital ulcerations as well as intraocular inflammation. Recurrent retinal vasoocclusive episodes and macular involvement may lead to severe loss of visual acuity. Patients may eventually become resistant to systemic corticosteroid and develop side effects; therefore, other immunosuppressive therapies are needed. Biologic agents are promising for the treatment of Behçet's disease-associated uveitis. Here, we report two cases of paediatric uveitis due to Behçet's disease that were successfully treated by early administration of adalimumab.

CASE PRESENTATION

Patient 1 was an 11-year-old girl who presented with right conjunctival injection and photophobia. Patient 2 was a 14-year-old girl who presented with blurry vision in the left eye. Both patients were treated with topical treatment and prednisolone for uveitis; however, relapses occurred during the tapering of prednisolone. The patients were diagnosed with Behçet's disease, and adalimumab therapy was initiated. In both cases, the inflammation was well-controlled by adalimumab administration without local or systemic corticosteroid.

CONCLUSIONS

Adalimumab is effective for treating children with Behçet's disease-associated uveitis. Control of ocular inflammation was achieved without local and systemic corticosteroid, thus preventing further complications.