Unmet need in rheumatology: reports from the Advances in Targeted Therapies meeting, 2023.

The Advances in Targeted Therapies meets annually, convening experts in the field of rheumatology to both provide scientific updates and identify existing scientific gaps within the field. To review the major unmet scientific needs in rheumatology. The 23rd annual Advances in Targeted Therapies meeting convened with more than 100 international basic scientists and clinical researchers in rheumatology, immunology, infectious diseases, epidemiology, molecular biology and other specialties relating to all aspects of immune-mediated inflammatory diseases. We held breakout sessions in five rheumatological disease-specific groups including: rheumatoid arthritis (RA), psoriatic arthritis (PsA), axial spondyloarthritis (axSpa), systemic lupus erythematosus (SLE), systemic sclerosis (SSc) and vasculitis, and osteoarthritis (OA). In each group, experts were asked to identify and prioritise current unmet needs in clinical and translational research. An overarching theme across all disease states is the continued need for clinical trial design innovation with regard to therapeutics, endpoint and disease endotypes. Within RA, unmet needs comprise molecular classification of disease pathogenesis and activity, pre-/early RA strategies, more refined pain profiling and innovative trials designs to deliver on precision medicine. Continued scientific questions within PsA include evaluating the genetic, immunophenotypic, clinical signatures that predict development of PsA in patients with psoriasis, and the evaluation of combination therapies for difficult-to-treat disease. For axSpA, there continues to be the need to understand the role of interleukin-23 (IL-23) in pathogenesis and the genetic relationship of the IL-23-receptor polymorphism with other related systemic inflammatory diseases (eg, inflammatory bowel disease). A major unmet need in the OA field remains the need to develop the ability to reliably phenotype and stratify patients for inclusion in clinical trials. SLE experts identified a number of unmet needs within clinical trial design including the need for allowing endpoints that reflect pharmacodynamic/functional outcomes (eg, inhibition of type I interferon pathway activation; changes in urine biomarkers). Lastly, within SSc and vasculitis, there is a lack of biomarkers that predict response or disease progression, and that allow patients to be stratified for therapies. There remains a strong need to innovate clinical trial design, to identify systemic and tissue-level biomarkers that predict progression or response to therapy, endotype disease, and to continue developing therapies and therapeutic strategies for those with treatment-refractory disease. This document, based on expert consensus, should provide a roadmap for prioritising scientific endeavour in the field of rheumatology.

Type I interferon and neutrophil transcripts in lupus nephritis renal biopsies: clinical and histopathological associations.

OBJECTIVES: To investigate the expression of type I IFN (IFN-I) and neutrophil transcripts in kidney tissue from patients with different classes of LN and their association with distinct clinical and histopathological features. METHODS: Quantitation of IFN-I, defensin-α3 and formyl peptide receptor-like 1 (FPRL-1) transcripts was performed in kidney biopsy tissue from 24 patients with various classes of LN (6 class III, 14 class IV, 4 class V) and 3 control samples. Patient demographics, glomerular filtration rate (eGFR) and histopathological characteristics, including activity and chronicity indices, were analysed. RESULTS: IFNα2 and IFNß transcripts were overexpressed in renal tissues from patients with proliferative forms of LN (III/IV) compared with patients with membranous nephritis and control kidneys. Patients with LN and impaired renal function, attested by eGFR, displayed higher relative expression of IFNα2 transcripts in renal tissues compared with those with normal renal function (23.0 ± 16.2 vs 12.0 ± 14.8, P = 0.04). Defensin-α3, but not FPRL-1, transcripts were overexpressed in LN tissues, particularly those with segmental necrotizing lesions, and were correlated with higher renal pathological activity indices (r = 0.61, P = 0.02), urinary protein levels (r = 0.44, P = 0.048) and IFNα2 expression (r = 0.50, P = 0.01). CONCLUSION: IFN-I transcripts are expressed locally in kidneys from patients with proliferative LN and are associated with impaired renal function. Elevated defensin-α3 transcripts, a neutrophil product associated with neutrophil extracellular traps, may identify a driver of local IFN-I expression. These findings provide insights into the mechanisms of proliferative LN and may inform therapeutic decisions regarding selection of IFN-I pathway inhibitors.

Consensus statement on blocking interleukin-6 receptor and interleukin-6 in inflammatory conditions: an update.

BACKGROUND: Targeting interleukin (IL)-6 has become a major therapeutic strategy in the treatment of immune-mediated inflammatory disease. Interference with the IL-6 pathway can be directed at the specific receptor using anti-IL-6Rα antibodies or by directly inhibiting the IL-6 cytokine. This paper is an update of a previous consensus document, based on most recent evidence and expert opinion, that aims to inform on the medical use of interfering with the IL-6 pathway. METHODS: A systematic literature research was performed that focused on IL-6-pathway inhibitors in inflammatory diseases. Evidence was put in context by a large group of international experts and patients in a subsequent consensus process. All were involved in formulating the consensus statements, and in the preparation of this document. RESULTS: The consensus process covered relevant aspects of dosing and populations for different indications of IL-6 pathway inhibitors that are approved across the world, including rheumatoid arthritis, polyarticular-course and systemic juvenile idiopathic arthritis, giant cell arteritis, Takayasu arteritis, adult-onset Still's disease, Castleman's disease, chimeric antigen receptor-T-cell-induced cytokine release syndrome, neuromyelitis optica spectrum disorder and severe COVID-19. Also addressed were other clinical aspects of the use of IL-6 pathway inhibitors, including pretreatment screening, safety, contraindications and monitoring. CONCLUSIONS: The document provides a comprehensive consensus on the use of IL-6 inhibition to treat inflammatory disorders to inform healthcare professionals (including researchers), patients, administrators and payers.

When a Diagnosis Has No Name: Uncertainty and Opportunity.

Diagnostic uncertainty, commonly encountered in rheumatology and other fields of medicine, is an opportunity: Stakeholders who understand uncertainty's causes and quantitate its effects can reduce uncertainty and can use uncertainty to improve medical practice, science, and administration. To articulate, bring attention to, and offer recommendations for diagnostic uncertainty, the Barbara Volcker Center at the Hospital for Special Surgery sponsored, in April 2021, a virtual international workshop, "When a Diagnosis Has No Name." This paper summarizes the opinions of 72 stakeholders from the fields of medical research, industry, federal regulatory agencies, insurers, hospital management, medical philosophy, public media, health care law, clinical rheumatology, other specialty areas of medicine, and patients. Speakers addressed the effects of diagnostic uncertainty in their fields. The workshop addressed the following six questions: What is a diagnosis? What are the purposes of diagnoses? How do doctors assign diagnoses? What is uncertainty? What are its causes? How does understanding uncertainty offer opportunities to improve all fields of medicine? The workshop's conveners systematically reviewed video recordings of formal presentations, video recordings of open discussion periods, manuscripts, and slide files submitted by the speakers to develop consensus take-home messages, which were as follows: Diagnostic uncertainty causes harm when patients lack access to laboratory test and treatments, do not participate in research studies, are not counted in administrative and public health documents, and suffer humiliation in their interactions with others. Uncertainty offers opportunities, such as quantifying uncertainty, using statistical technologies and automated intelligence to stratify patient groups by level of uncertainty, using a common vocabulary, and considering the effects of time.

European League Against Rheumatism (EULAR)/American College of Rheumatology (ACR) SLE classification criteria item performance.

BACKGROUND/OBJECTIVES: The European League Against Rheumatism (EULAR)/American College of Rheumatology (ACR) 2019 classification criteria for systemic lupus erythematosus system showed high specificity, while attaining also high sensitivity. We hereby analysed the performance of the individual criteria items and their contribution to the overall performance of the criteria. METHODS: We combined the EULAR/ACR derivation and validation cohorts for a total of 1197 systemic lupus erythematosus (SLE) and n=1074 non-SLE patients with a variety of conditions mimicking SLE, such as other autoimmune diseases, and calculated the sensitivity and specificity for antinuclear antibodies (ANA) and the 23 specific criteria items. We also tested performance omitting the EULAR/ACR criteria attribution rule, which defines that items are only counted if not more likely explained by a cause other than SLE. RESULTS: Positive ANA, the new entry criterion, was 99.5% sensitive, but only 19.4% specific, against a non-SLE population that included other inflammatory rheumatic, infectious, malignant and metabolic diseases. The specific criteria items were highly variable in sensitivity (from 0.42% for delirium and 1.84% for psychosis to 75.6% for antibodies to double-stranded DNA), but their specificity was uniformly high, with low C3 or C4 (83.0%) and leucopenia <4.000/mm³ (83.8%) at the lowest end. Unexplained fever was 95.3% specific in this cohort. Applying the attribution rule improved specificity, particularly for joint involvement. CONCLUSIONS: Changing the position of the highly sensitive, non-specific ANA to an entry criterion and the attribution rule resulted in a specificity of >80% for all items, explaining the higher overall specificity of the criteria set.

Expression of APOBEC family members as regulators of endogenous retroelements and malignant transformation in systemic autoimmunity.

OBJECTIVE: To explore whether APOBEC family members are involved in the response to inappropriate expression of L1 retroelements in primary Sjögren's syndrome (SS) and systemic lupus erythematosus (SLE), as well as in SS related lymphomagenesis. METHODS: Minor salivary glands (MSG) and kidney biopsy (KB) specimens were obtained from 41 SS patients (10 with lymphoma) and 23 patients with SLE, respectively. PBMC and sera were also collected from 73 SLE patients. Full-length L1 transcripts, members of the APOBEC and IFN family were quantitated by real time PCR. Type I IFN activity was assessed in lupus plasma by a cell assay. RESULTS: APOBEC3A was increased in SS MSG, SLE KB and PBMC and correlated with L1. AID and APOBEC3G were particularly overexpressed in MSG tissues derived from SS lymphoma patients. CONCLUSION: These data reveal a previously unappreciated role of APOBEC family proteins in the pathogenesis of systemic autoimmunity and SS related lymphomagenesis.

TREX1 variants in Sjogren's syndrome related lymphomagenesis.

Genetic variants of the three-prime repair exonuclease 1 (TREX1) -an exonuclease involved in DNA repair and degradation- have been previously found to increase susceptibility to Aicardi Goutieres syndrome, familial chilblain lupus and systemic lupus erythematosus. We aimed to explore whether TREX1 common variants could influence the risk of primary Sjogren's syndrome (SS) and SS-related lymphoma. Three single nucleotide polymorphisms (SNPs) of the TREX1 gene (rs11797, rs3135941 and rs3135945) were evaluated in 229 SS, 89 SS-lymphoma (70 SS-MALT and 19 SS non-MALT) and 240 healthy controls by PCR-based assays. In available 52 peripheral blood and 26 minor salivary gland tissues from our SS cohort, mRNA expression of type I interferon (IFN) related genes and TREX1 was determined by real-time PCR. Significantly decreased prevalence of rs11797 A minor allele was detected in SS patients complicated by non-MALT lymphoma compared to controls (ΟR [95% CI]: 0.4 [0.2-0.9], p-value: 0.02). SS patients carrying the rs11797 AA genotype had increased type I IFN related gene mRNA expression in minor salivary gland tissues. These data support genetically related dampened type I IFN production as an additional mechanism for SS-related lymphomagenesis.

Type I interferons in host defence and inflammatory diseases.

Type I interferons (IFN) can have dual and opposing roles in immunity, with effects that are beneficial or detrimental to the individual depending on whether IFN pathway activation is transient or sustained. Determinants of IFN production and its functional consequences include the nature of the microbial or nucleic acid stimulus, the type of nucleic acid sensor involved in inducing IFN, the predominant subtype of type I IFN produced and the immune ecology of the tissue at the time of IFN expression. When dysregulated, the type I IFN system drives many autoimmune and non-autoimmune inflammatory diseases, including SLE and the tissue inflammation associated with chronic infection. The type I IFN system may also contribute to outcomes for patients affected by solid cancers or myocardial infarction. Significantly more research is needed to discern the mechanisms of induction and response to type I IFNs across these diseases, and patient endophenotyping may help determine whether the cytokine is acting as 'friend' or 'foe', within a particular patient, and at the time of treatment. This review summarises key concepts and discussions from the second International Summit on Interferons in Inflammatory Diseases, during which expert clinicians and scientists evaluated the evidence for the role of type I IFNs in autoimmune and other inflammatory diseases.

Defective regulation of L1 endogenous retroelements in primary Sjogren's syndrome and systemic lupus erythematosus: Role of methylating enzymes.

OBJECTIVE: To investigate whether altered DNA methylation contributes to the inappropriate expression of LINE-1 (L1) retroelements in primary Sjogren's syndrome (SS) and systemic lupus erythematosus (SLE). METHODS: Minor salivary glands (MSG) were obtained from 42 patients with primary SS [23 without adverse predictors for lymphoma development (SS-low risk), 7 SS-high risk and 12 complicated by B-cell lymphoma (SS-lymphoma)] and 17 sicca controls (SC). Additionally, kidney biopsy specimens and PBMCs were obtained from 23 and 73 lupus patients, respectively. Relative mRNA expression was quantified for full-length L1 transcripts, along with mediators of methylation. In an independent set of 44 MSG samples (11 SS-low risk, 10 SS-high risk, 15 SS-lymphoma and 8 SC), methylation levels of the L1 promoter were determined by bisulphite pyrosequencing. RESULTS: A strong positive correlation was demonstrated between L1 transcripts and gene products that mediate de novo and constitutive DNA methylation, DNA methyltransferase (DNMT)3B, DNMT1, and methyl CpG binding protein 2 (MeCP2), in both SS MSG and lupus renal tissues. A significant negative correlation was observed between expression of L1 and lymphoid-specific helicase (LSH, encoded by HELLS) in both SS MSG and SLE kidney tissues, as well as between DNMT3A transcripts and L1 expression in SLE kidney tissues and PBMCs. Reduced levels of L1 promoter methylation along with increased DNMT3B, DNMT1, and MeCP2, but reduced LSH levels were detected in SS-low risk patients compared to both SS-lymphoma and SC. The SS-lymphoma group was also characterized by a profound decrease of MeCP2 and DNMT3B compared to SC. CONCLUSION: Our data support a contributory role of altered methylation mechanisms in the pathogenesis of systemic autoimmune disorders and related lymphoproliferative processes and suggest that LSH and DNMT3A should be investigated as candidate upstream mediators of decreased L1 promoter methylation and increased L1 expression.

MTHFR gene variants and non-MALT lymphoma development in primary Sjogren's syndrome.

Primary Sjogren's syndrome (pSS) confers increased risk for non-Hodgkin lymphoma (NHL) development. Two common polymorphisms, the c. 677C > T and c. 1298A > C, of the methylene-tetrahydrofolate reductase (MTHFR) gene, an enzyme essential in DNA synthesis and methylation, have been associated with susceptibility to NHL. Herein, we tested the hypothesis that MTHFR variants contribute to pSS-related lymphomagenesis. 356 pSS patients, of whom 75 had MALT and 19 non-MALT NHL and 600 healthy controls were genotyped for the detection of MTHFR polymorphisms. DNA methylation levels were assessed by pyrosequencing of the LINE-1 retroelement promoter in DNA from 55 salivary gland tissues from pSS patients. DNA double-strand breaks were determined in peripheral blood mononuclear cells from 13 pSS patients, using comet assay. Αnalysis according to lymphoma subtype revealed increased frequency of c. 677C > T TT genotype and T allele, as well as reduced prevalence of the c. 1298A > C C allele in the pSS non-MALT group compared to controls and patients without NHL. MTHFR c. 677C > T TT genotype was associated with reduced DNA methylation levels, while MTHFR c. 1298A > C AC genotype with reduced DNA double-strand breaks levels. MTHFR variants may be involved in SS non-MALT NHL development, through contribution to defective DNA methylation and genomic instability.

Reactive oxygen species induce virus-independent MAVS oligomerization in systemic lupus erythematosus.

The increased expression of genes induced by type I interferon (IFN) is characteristic of viral infections and systemic lupus erythematosus (SLE). We showed that mitochondrial antiviral signaling (MAVS) protein, which normally forms a complex with retinoic acid gene I (RIG-I)-like helicases during viral infection, was activated by oxidative stress independently of RIG-I helicases. We found that chemically generated oxidative stress stimulated the formation of MAVS oligomers, which led to mitochondrial hyperpolarization and decreased adenosine triphosphate production and spare respiratory capacity, responses that were not observed in similarly treated cells lacking MAVS. Peripheral blood lymphocytes of SLE patients also showed spontaneous MAVS oligomerization that correlated with the increased secretion of type I IFN and mitochondrial oxidative stress. Furthermore, inhibition of mitochondrial reactive oxygen species (ROS) by the mitochondria-targeted antioxidant MitoQ prevented MAVS oligomerization and type I IFN production. ROS-dependent MAVS oligomerization and type I IFN production were reduced in cells expressing the MAVS-C79F variant, which occurs in 30% of sub-Saharan Africans and is linked with reduced type I IFN secretion and milder disease in SLE patients. Patients expressing the MAVS-C79F variant also had reduced amounts of oligomerized MAVS in their plasma compared to healthy controls. Together, our findings suggest that oxidative stress-induced MAVS oligomerization in SLE patients may contribute to the type I IFN signature that is characteristic of this syndrome.

Systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is an autoimmune disease that can affect many organs, including the skin, joints, the central nervous system and the kidneys. Women of childbearing age and certain racial groups are typically predisposed to developing the condition. Rare, inherited, single-gene complement deficiencies are strongly associated with SLE, but the disease is inherited in a polygenic manner in most patients. Genetic interactions with environmental factors, particularly UV light exposure, Epstein-Barr virus infection and hormonal factors, might initiate the disease, resulting in immune dysregulation at the level of cytokines, T cells, B cells and macrophages. Diagnosis is primarily clinical and remains challenging because of the heterogeneity of SLE. Classification criteria have aided clinical trials, but, despite this, only one drug (that is, belimumab) has been approved for use in SLE in the past 60 years. The 10-year mortality has improved and toxic adverse effects of older medications such as cyclophosphamide and glucocorticoids have been partially offset by newer drugs such as mycophenolate mofetil and glucocorticoid-sparing regimes. However, further improvements have been hampered by the adverse effects of renal and neuropsychiatric involvement and late diagnosis. Adding to this burden is the increased risk of premature cardiovascular disease in SLE together with the risk of infection made worse by immunosuppressive therapy. Challenges remain with treatment-resistant disease and symptoms such as fatigue. Newer therapies may bring hope of better outcomes, and the refinement to stem cell and genetic techniques might offer a cure in the future.

Type I and II interferon signatures in Sjogren's syndrome pathogenesis: Contributions in distinct clinical phenotypes and Sjogren's related lymphomagenesis.

Both type I and II interferons (IFNs) have been implicated in the pathogenesis of Sjogren's syndrome (SS). We aimed to explore the contribution of type I and II IFN signatures in the generation of distinct SS clinical phenotypes including lymphoma development. Peripheral blood (PB) from SS patients (n = 31), SS patients complicated by lymphoma (n = 13) and healthy controls (HC, n = 30) were subjected to real-time PCR for 3 interferon inducible genes (IFIGs) preferentially induced by type I IFN, 2 IFIGs preferentially induced by IFNγ as well as for IFNα and IFNγ genes. The same analysis was performed in minor salivary gland tissues (MSG) derived from 31 SS patients, 10 SS-lymphoma patients and 17 sicca controls (SC). In PB and MSG tissues, overexpression of both type I and type II IFIGs was observed in SS patients versus HC and SC, respectively, with a predominance of type I IFN signature in PB and a type II IFN signature in MSG tissues. In SS-lymphoma MSG tissues, lower IFNα, but higher IFNγ and type II IFIG transcripts compared to both SS and SC were observed. In receiver operating characteristic curve analysis, IFNγ/IFNα mRNA ratio in MSG tissues showed the best discrimination for lymphoma development. Discrete expression patterns of type I and II IFN signatures might be related to distinct SS clinical phenotypes. Additionally, IFNγ/IFNα mRNA ratio in diagnostic salivary gland biopsies is proposed as a novel histopathological biomarker for the prediction of in situ lymphoma development in the setting of SS.

Interferon-α and angiogenic dysregulation in pregnant lupus patients who develop preeclampsia.

OBJECTIVE: To investigate whether an elevated interferon-α (IFNα) level early in pregnancy is associated with poor pregnancy outcomes and to examine the relationship of an elevated IFNα level to angiogenic imbalance. METHODS: Women were enrolled in a longitudinal case-control study of pregnant patients with lupus. Serum samples obtained monthly throughout pregnancy were assayed for IFNα and for the antiangiogenic factor soluble Flt-1 and the proangiogenic factor placenta growth factor (PlGF). Each of 28 patients with systemic lupus erythematosus (SLE) with a poor pregnancy outcome was matched to an SLE patient with an uncomplicated pregnancy and to a pregnant healthy control. The effects of IFNα and/or soluble Flt-1 on human endothelial cells and endothelial cell-trophoblast interactions were assessed. RESULTS: Compared to SLE patients with uncomplicated pregnancies, patients with preeclampsia had increased IFNα levels before clinical symptoms. Patients without autoimmune disease who developed preeclampsia did not have increased IFNα levels. In SLE patients with low IFNα levels, marked angiogenic imbalance (higher soluble Flt-1, lower PlGF, and higher soluble Flt-1:PlGF ratios) preceded maternal manifestations of preeclampsia, whereas in SLE patients with high IFNα levels, preeclampsia occurred without evidence of systemic angiogenic imbalance. Treatment of human endothelial cells with soluble Flt-1 induced expression of sFLT1 messenger RNA, and IFNα dramatically amplified responses to soluble Flt-1. In a model of spiral artery transformation, only the combination of IFNα and soluble Flt-1 disrupted the ability of trophoblast cells to remodel endothelial tube structures. CONCLUSION: Our findings identify a new mechanism by which IFNα induces an antiangiogenic milieu and increases the sensitivity of endothelial cells to soluble Flt-1, and suggest that elevated IFNα levels may contribute to the pathogenesis of preeclampsia in some pregnant patients with SLE.

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.

Synovial fluid from patients with early osteoarthritis modulates fibroblast-like synoviocyte responses to toll-like receptor 4 and toll-like receptor 2 ligands via soluble CD14.

OBJECTIVE: Synovial inflammation, a feature of both osteoarthritis (OA) and meniscal injury, is hypothesized to be triggered in part via stimulation of Toll-like receptors (TLRs). We undertook this study to test whether a TLR-2- or TLR-4-stimulating factor in synovial fluid (SF) from patients with early knee OA with meniscal injury could lead to inflammatory activation of synoviocytes. METHODS: SF was obtained from patients with early OA cartilage damage undergoing arthroscopic meniscal procedures. SF was used to stimulate primary cultures of fibroblast-like synoviocytes (FLS) and cell lines transfected with TLR-2 or TLR-4. SF was used either alone or in combination with a TLR-2 stimulus (palmitoyl-3-cysteine-serine-lysine-4 [Pam3CSK4]) or a TLR-4 stimulus (lipopolysaccharide [LPS]). In blocking experiments, SF was preincubated with anti-CD14 antibody. RESULTS: SF from these patients did not stimulate interleukin-8 (IL-8) release from TLR transfectants. Compared with SF on its own, SF (at concentrations of 0.09-25%) in combination with TLR-2 or TLR-4 ligands resulted in significant augmentation of IL-8 release from both transfectants and primary FLS. Soluble CD14 (sCD14), a coreceptor for TLRs, was measured in SF from patients with early OA at levels comparable to those in patients with advanced OA and patients with rheumatoid arthritis. Blockade with anti-CD14 antibody abolished the ability of SF to augment IL-8 production in response to LPS, and diminished Pam3CSK4 responses. CONCLUSION: SF augments FLS responses to TLR-2 and TLR-4 ligands. This effect was largely due to sCD14. Our results demonstrate that sCD14 in the setting of OA and meniscal injury sensitizes FLS to respond to inflammatory stimuli such as TLR ligands.

Autoimmune disease risk variant of IFIH1 is associated with increased sensitivity to IFN-α and serologic autoimmunity in lupus patients.

Increased IFN-α signaling is a heritable risk factor for systemic lupus erythematosus (SLE). IFN induced with helicase C domain 1 (IFIH1) is a cytoplasmic dsRNA sensor that activates IFN-α pathway signaling. We studied the impact of the autoimmune-disease-associated IFIH1 rs1990760 (A946T) single nucleotide polymorphism upon IFN-α signaling in SLE patients in vivo. We studied 563 SLE patients (278 African-American, 179 European-American, and 106 Hispanic-American). Logistic regression models were used to detect genetic associations with autoantibody traits, and multiple linear regression was used to analyze IFN-α-induced gene expression in PBMCs in the context of serum IFN-α in the same blood sample. We found that the rs1990760 T allele was associated with anti-dsDNA Abs across all of the studied ancestral backgrounds (meta-analysis odds ratio = 1.34, p = 0.026). This allele also was associated with lower serum IFN-α levels in subjects who had anti-dsDNA Abs (p = 0.0026). When we studied simultaneous serum and PBMC samples from SLE patients, we found that the IFIH1 rs1990760 T allele was associated with increased IFN-induced gene expression in PBMCs in response to a given amount of serum IFN-α in anti-dsDNA-positive patients. This effect was independent of the STAT4 genotype, which modulates sensitivity to IFN-α in a similar way. Thus, the IFIH1 rs1990760 T allele was associated with dsDNA Abs, and in patients with anti-dsDNA Abs this risk allele increased sensitivity to IFN-α signaling. These studies suggest a role for the IFIH1 risk allele in SLE in vivo.

Imatinib mesylate (Gleevec) in the treatment of diffuse cutaneous systemic sclerosis: results of a 1-year, phase IIa, single-arm, open-label clinical trial.

OBJECTIVE: To assess the safety and effectiveness of imatinib mesylate in the treatment of diffuse cutaneous systemic sclerosis (dcSSc). METHODS: In this phase IIa, open-label, single-arm clinical trial, 30 patients with dcSSc were treated with imatinib 400 mg daily. Patients were monitored monthly for safety assessments. Modified Rodnan skin scores (MRSS) were assessed every 3 months. Pulmonary function testing, chest radiography, echocardiography and skin biopsies were performed at baseline and after 12 months of treatment. RESULTS: Twenty-four patients completed 12 months of therapy. 171 adverse events (AE) with possible relation to imatinib were identified; 97.6% were grade 1 or 2. Twenty-four serious AE were identified, two of which were attributed to study medication. MRSS decreased by 6.6 points or 22.4% at 12 months (p=0.001). This change was evident starting at the 6-month time point (Δ=-4.5; p<0.001) and was seen in patients with both early and late-stage disease. Forced vital capacity (FVC) improved by 6.4% predicted (p=0.008), and the diffusion capacity remained stable. The improvement in FVC was significantly greater in patients without interstitial lung disease. Health-related quality of life measures improved or remained stable. Blinded dermatopathological analysis confirmed a significant decrease in skin thickness and improvement in skin morphology. CONCLUSIONS: Treatment with imatinib was tolerated by most patients in this cohort. Although AE were common, most were mild to moderate. In this open-label experience, improvements in skin thickening and FVC were observed. Further investigation of tyrosine kinase inhibition for dcSSc in a double-blind randomised placebo controlled trial is warranted. ClinicalTrials.gov, NCT00555581.

Degos disease: a C5b-9/interferon-α-mediated endotheliopathy syndrome.

Degos disease is a lethal small vessel angiopathy targeting the skin, gastrointestinal tract, and central nervous system, potentially developing in the setting of known autoimmune disease, although forme fruste primary variants exist. Its pathogenetic basis is unknown. Four cases of Degos disease were encountered in archival material, representing 2 men, ages 38 and 43 years, and 2 females, ages 48 and 2 years; 3 patients died of disease. All had characteristic skin lesions with gastrointestinal involvement; other affected organs included brain in one and pericardium and pleura in another. Skin biopsies showed pauci-inflammatory thrombogenic microangiopathy with endothelial cell injury. Extracutaneous organs demonstrated fibromucinous occlusive arteriopathy. Prominent vascular C5b-9 was seen in the skin, gastrointestinal tract, and brain. All cases had evidence of high expression of interferon-α (based on tissue expression of MXA, a type I interferon-inducible protein), endothelial tubuloreticular inclusions, and an interferon gene signature in peripheral blood mononuclear cells. The MXA expression paralleled the pattern of C5b-9 deposition. Degos disease is a distinct vascular injury syndrome whereby a dysregulated interferon-α response in concert with membranolytic attack complex deposition may contribute to the unique vascular changes. Understanding the pathophysiology of the disease process could lead to more directed therapies, including terminal complement inhibition with agents such as eculizumab.

Synovial inflammation in patients undergoing arthroscopic meniscectomy: molecular characterization and relationship to symptoms.

OBJECTIVE: Traumatic and degenerative meniscal tears have different anatomic features and different proposed etiologies, yet both are associated with the development or progression of osteoarthritis (OA). In established OA, synovitis is associated with pain and progression, but a relationship between synovitis and symptoms in isolated meniscal disease has not been reported. Accordingly, we sought to characterize synovial pathology in patients with traumatic meniscal injuries and determine the relationships between inflammation, meniscal and cartilage pathology, and symptoms. METHODS: Thirty-three patients without evidence of OA who were undergoing arthroscopic meniscectomy for meniscal injuries were recruited. Pain and function were assessed preoperatively; meniscal and cartilage abnormalities were documented at the time of surgery. Inflammation in synovial biopsy specimens was scored, and associations between inflammation and clinical outcomes were determined. Microarray analysis of synovial tissue was performed, and gene expression patterns in patients with and those without inflammation were compared. RESULTS: Synovial inflammation was present in 43% of the patients and was associated with worse preoperative pain and function scores, independent of age, sex, or cartilage pathology. Microarray analysis and real-time polymerase chain reaction revealed a chemokine signature in synovial biopsy specimens with increased inflammation scores. CONCLUSION: Our findings indicate that in patients with traumatic meniscal injury undergoing arthroscopic meniscectomy without radiographic evidence of OA, synovial inflammation occurs frequently and is associated with increased pain and dysfunction. Synovia with increased inflammation scores exhibit a unique chemokine signature. Chemokines may contribute to the development of synovial inflammation in patients with meniscal pathology; they also represent potential therapeutic targets for reducing inflammatory symptoms.