Evolution of monoclonal gammopathy of undetermined significance in patients treated with JAK inhibitors for rheumatic diseases: data from the MAJIK-SFR registry.

OBJECTIVE: Monoclonal gammopathy of undetermined significance (MGUS) is common, but there are scarce data regarding the effect of DMARDs on this premalignant condition. We aimed to evaluate the impact of JAK inhibitors (JAKis) on MGUS when initiated for an active rheumatic disease. METHODS: Patients with monoclonal abnormality prior to JAKi initiation for an active rheumatic disease were identified through the MAJIK-SFR Registry, a French multicentre prospective study. Clinical and biological data were collected using a standardized case report form. RESULTS: Twenty patients were identified with a mean age of 65 years and a diagnosis of RA (n = 15), PsA (n = 3), and axial SpA (n = 2). The JAKi prescribed was baricitinib (n = 9), tofacitinib (n = 6) or upadacitinib (n = 5), with a mean duration of 15.5 months. Seventeen patients had individualized serum monoclonal protein (IgG kappa n = 9; IgG lambda n = 4; IgM kappa n = 3; IgA lambda n = 1) ranging from 0.16 to 2.3 g/dl, and three patients did not have an initial measurable spike but they had a positive serum immunofixation. With a follow-up of 4-28 months, the serum monoclonal protein level decreased in 8 of 17 patients (47%), remained stable in 8 patients (47%) and increased in 1 patient (6%). The maximal decrease observed was an initial IgG kappa of 2.3 g/dl, decreasing to 0.2 g/dl at month 14. CONCLUSION: This study provides reassuring and promising data on MGUS evolution in patients treated with JAKis for rheumatic diseases, which may guide the choice of treatment in patients with both conditions.

Towards the Lowest Efficacious Dose: Results From a Multicenter Noninferiority Randomized Open-Label Controlled Trial Assessing Tocilizumab or Abatacept Injection Spacing in Rheumatoid Arthritis in Remission.

OBJECTIVE: We assess the clinical and structural impact at two years of progressively spacing tocilizumab (TCZ) or abatacept (ABA) injections versus maintenance at full dose in patients with rheumatoid arthritis in sustained remission. METHODS: This multicenter open-label noninferiority (NI) randomized clinical trial included patients with established rheumatoid arthritis in sustained remission receiving ABA or TCZ at a stable dose. Patients were randomized to treatment maintenance (M) at full dose (M-arm) or progressive injection spacing (S) driven by the Disease Activity Score in 28 joints every 3 months up to biologics discontinuation (S-arm). The primary end point was the evolution of disease activity according to the Disease Activity Score in 44 joints during the 2-year follow-up analyzed per protocol with a linear mixed-effects model, evaluated by an NI test based on the one-sided 95% confidence interval (95% CI) of the slope difference (NI margin 0.25). Other end points were flare incidence and structural damage progression. RESULTS: Overall, 202 of the 233 patients included were considered for per protocol analysis (90 in S-arm and 112 in M-arm). At the end of follow-up, 16.2% of the patients in the S-arm could discontinue their biologic disease-modifying antirheumatic drug, 46.9% tapered the dose and 36.9% returned to a full dose. NI was not demonstrated for the primary outcome, with a slope difference of 0.10 (95% CI 0.10-0.31) between the two arms. NI was not demonstrated for flare incidence (difference 42.6%, 95% CI 30.0-55.1) or rate of structural damage progression at two years (difference 13.9%, 95% CI -6.7 to 34.4). CONCLUSION: The Towards the Lowest Efficacious Dose trial failed to demonstrate NI for the proposed ABA or TCZ tapering strategy.

Immune checkpoint inhibitor rechallenge in patients who previously experienced immune-related inflammatory arthritis: a multicentre observational study.

OBJECTIVE: Another course of immune checkpoint inhibitors (ICIs) is often considered in patients with cancer progression and previous immune-related adverse events, including inflammatory arthritis (ICI-IA), but there are limited data regarding safety of ICI rechallenge in this setting. We aimed to assess the rate and clinical features associated with ICI-IA flare/recurrence on ICI rechallenge. METHODS: We conducted a multicentre observational study including cancer patients with ICI-IA who started a second course of ICI more than 3 months after ICI discontinuation in four French university hospitals. Primary outcome was the frequency of ICI flare/recurrence after ICI rechallenge. RESULTS: Twenty-three patients were included. At the time of ICI rechallenge, 18 patients reported no symptoms of ICI-IA (78%) and 5 had grade 1 (22%), 11 patients (48%) were not receiving any ICI-IA treatment, 11 (48%) were still on prednisone, 2 (9%) were on conventional synthetic disease-modifying antirheumatic drugs and 1 (4%) on anti-IL-6. ICI-IA flare/recurrence occurred in 12 patients (52%) with a median time of 1 month after ICI rechallenge. ICI-IA phenotype, disease activity and ICI-IA treatment at the time of ICI rechallenge did not differ according to ICI-IA flare/recurrence status. CONCLUSION: In this first observational study of ICI-IA patients rechallenged with ICI, about half of the patients experienced ICI-IA flare/recurrence with a similar phenotype but occurring earlier than the initial ICI-IA, warranting close monitoring during the first month of retreatment. Risk of flare did not differ according to baseline immunosuppressive treatment at the time of rechallenge.

Can efficacy and safety data from clinical trials of rituximab in RA be extrapolated? Insights from 1984 patients from the AIR-PR Registry.

OBJECTIVES: To investigate whether the efficacy and safety data from drug-registration trials can be extrapolated to real-life RA patients receiving RTX. METHODS: The AIR-PR registry is a French multicentre, prospective cohort of RA patients treated with RTX in a real-life setting. We compared treatment responses at 12 months and serious AEs between eligible and non-eligible patients, by retrieving the eligibility criteria of the three rituximab-registration trials. We determined critical eligibility criteria and modelled the benefit-risk ratio according to the number of fulfilled critical eligibility criteria. RESULTS: Among 1984 RA patients, only 9-12% fulfilled all eligibility criteria. Non-eligible patients had less EULAR response at 12 months (40.3% vs 46.9%, p= 0.044). Critical inclusion criteria included SJC ≥ 4, TJC ≥ 4, CRP ≥ 15 mg/l, and RF positivity. Critical exclusion criteria were age >80 years, RA-associated systemic diseases, ACR functional class IV, other DMARD than methotrexate, and prednisone > 10 mg/day. Only 20.8% fulfilled those critical eligibility criteria. During the first year, serious AEs occurred for 182 (9.2%) patients, (70.3% serious infections) and patients with ≥1 critical exclusion criterion were at higher risk (HR 3.03; 95%CI 2.25-4.06; for ≥ 3 criteria vs 0). The incremental risk-benefit ratio decreased with the number of unmet critical inclusion criteria and of fulfilled exclusion criteria. CONCLUSION: Few real-life RA patients were eligible for the drug-registration trials. Non-eligible patients had lower chance of response, and higher risk of serious AEs. Efficacy and safety data obtained from those trials may not be generalizable to RA patients receiving RTX in real-world clinical practice.

Effects of Lumacaftor-Ivacaftor on Airway Microbiota-Mycobiota and Inflammation in Patients with Cystic Fibrosis Appear To Be Linked to Pseudomonas aeruginosa Chronic Colonization.

Lumacaftor-ivacaftor is a cystic fibrosis transmembrane conductance regulator (CFTR) modulator combination approved for patients with cystic fibrosis (CF) who are homozygous for the F508del allele. This treatment showed significant clinical improvement; however, few studies have addressed the evolution of the airway microbiota-mycobiota and inflammation in patients receiving lumacaftor-ivacaftor treatment. Seventy-five patients with CF aged 12 years or older were enrolled at the initiation of lumacaftor-ivacaftor therapy. Among them, 41 had spontaneously produced sputa collected before and 6 months after treatment initiation. Airway microbiota and mycobiota analyses were performed via high-throughput sequencing. Airway inflammation was assessed by measuring the calprotectin levels in sputum; the microbial biomass was evaluated via quantitative PCR (qPCR). At baseline (n = 75), bacterial alpha-diversity was correlated with pulmonary function. After 6 months of lumacaftor-ivacaftor treatment, a significant improvement in the body mass index and a decreased number of intravenous antibiotic courses were noted. No significant changes in bacterial and fungal alpha- and beta-diversities, pathogen abundances, or calprotectin levels were observed. However, for patients not chronically colonized with Pseudomonas aeruginosa at treatment initiation, calprotectin levels were lower, and a significant increase in bacterial alpha-diversity was observed at 6 months. This study shows that the evolution of the airway microbiota-mycobiota in CF patients depends on the patient's characteristics at lumacaftor-ivacaftor treatment initiation, notably chronic colonization with P. aeruginosa. IMPORTANCE The management of cystic fibrosis has been transformed recently by the advent of CFTR modulators, including lumacaftor-ivacaftor. However, the effects of such therapies on the airway ecosystem, particularly on the microbiota-mycobiota and local inflammation, which are involved in the evolution of pulmonary damage, are unclear. This multicenter study of the evolution of the microbiota under protein therapy supports the notion that CFTR modulators should be started as soon as possible, ideally before the patient is chronically colonized with P. aeruginosa. (This study has been registered at ClinicalTrials.gov under identifier NCT03565692).

Clinical and immunological features of patients with cancer-associated systemic sclerosis: An observational study.

INTRODUCTION: Clinical and immunological features of patients with cancer-associated systemic sclerosis: an observational study. OBJECTIVE: Several studies have reported an increased incidence of cancer in patients with systemic sclerosis (SSc). The presence of RNA polymerase III antibodies (anti-RNA Pol 3) associates with an increased risk of cancer, but other risk factors need yet to be identified. We aimed to assess clinical and immunological predictive factors of cancer-associated SSc to guide clinicians when setting up selective cancer screening. METHODS: We conducted a monocentric, retrospective, observational study of SSc patients with and without associated malignancy. Clinical, laboratory and imaging data were collected, as well as SSc treatment. Subgroup analyses were performed according to the type of cancer and the time of diagnosis. RESULTS: Of 464 SSc patients, 74 (16%) had cancer, with breast (n=26) and lung cancer (n=13) being the most frequent. Diagnosis of cancer was made less than 3 years before or after SSc diagnosis for 23 patients (31%). In a multivariate analysis, anti-RNA Pol 3 and anti-SSA antibodies were significantly associated with an increased overall risk of cancer with an odds ratio (OR) of 4.12 (95% CI [1.6-10.7]; P<0.01) and 2.43 (95% CI [1.1-5.4]; P<0.05), respectively. Age at diagnosis of SSc and delay from the SSc diagnosis were also independent risk factors of cancer. Interstitial lung disease and anti-topoisomerase antibodies were associated with an increased risk of lung cancer and cancer occuring more than three years after SSc diagnosis. CONCLUSION: In addition to anti-RNA Pol 3 antibodies, anti-SSA antibodies associated with an increased risk of cancer in SSc patients. Interstitial lung disease was a risk factor specifically for lung cancer and cancers diagnosed more than 3 years after SSc diagnosis. For these patients, a systematic and regular cancer screening should be considered.

Stricter treat-to-target in RA does not result in less radiographic progression: a longitudinal analysis in RA BIODAM.

OBJECTIVES: To investigate whether meticulously following a treat-to-target (T2T)-strategy in daily clinical practice will lead to less radiographic progression in patients with active RA who start (new) DMARD-therapy. METHODS: Patients with RA from 10 countries starting/changing conventional synthetic or biologic DMARDs because of active RA, and in whom treatment intensification according to the T2T principle was pursued, were assessed for disease activity every 3 months for 2 years (RA-BIODAM cohort). The primary outcome was the change in Sharp-van der Heijde (SvdH) score, assessed every 6 months. Per 3-month interval DAS44-T2T could be followed zero, one or two times (in a total of two visits). The relation between T2T intensity and change in SvdH-score was modelled by generalized estimating equations. RESULTS: In total, 511 patients were included [mean (s.d.) age: 56 (13) years; 76% female]. Mean 2-year SvdH progression was 2.2 (4.1) units (median: 1 unit). A stricter application of T2T in a 3-month interval did not reduce progression in the same 6-month interval [parameter estimates (for yes vs no): +0.15 units (95% CI: -0.04, 0.33) for 2 vs 0 visits; and +0.08 units (-0.06; 0.22) for 1 vs 0 visits] nor did it reduce progression in the subsequent 6-month interval. CONCLUSIONS: In this daily practice cohort, following T2T principles more meticulously did not result in less radiographic progression than a somewhat more lenient attitude towards T2T. One possible interpretation of these results is that the intention to apply T2T already suffices and that a more stringent approach does not further improve outcome.

JAK inhibitors and risk of major cardiovascular events or venous thromboembolism: a self-controlled case series study.

PURPOSE: JAK-inhibitors (JAK-i) might be associated with venous (VTE) and arterial thromboembolic events (ATE). To evaluate the association between JAK-i and the risk of VTE and ATE. METHODS: A self-controlled case series was performed using data from the nationwide French healthcare insurance system database SNDS. We included all patients treated with JAK-i (baricitinib or tofacitinib), and having presented at least one VTE or ATE between November 1, 2017 and June 30, 2019. Associations were estimated using the incident rate ratio (IRR). Two post-exposure periods (until day 30 and until day 60) were individualized. RESULTS: Among 5870 patients with JAK-i dispensing, 92 had an incident VTE or ATE within the study period. Their median age at JAK-i initiation was 65.7 years [IQR: 56.1-75.8] and 65.2% were female (n = 60). Before event incidence, 65.2% (n = 60) received baricitinib, 32.6% (n = 30) tofacitinib and 2.2% (n = 2) had both medications. Moreover, 41.3% (n = 38) presented a VTE and 58.7% (n = 54) an ATE. The median time-to-onset after JAK-i initiation was 4.6 months [IQR: 2.5-9.2] for VTE and 6.1 months [IQR: 3.0-8.5] for ATE. An IRR of 8.27 (95% CI 3.41-20.04) for VTE was detected during JAK-i treatment and remained increased over the 30-day period of post-exposure (6.52 [2.02-21.11]). An IRR of 9.27 (3.68-23.34) was also found for ATE, which remained increased over the 30-day period of post-exposure (10.12 [3.27-31.37]). No increased risk was detected during long-term post-exposure for either VTE or ATE. CONCLUSIONS: This study shows evidence of an increased risk of VTE and ATE associated with the use of baricitinib and tofacitinib.

Use of a bDMARD or tsDMARD for the management of inflammatory arthritis under checkpoint inhibitors: an observational study.

OBJECTIVE: There is limited experience regarding the use of biological disease-modifying antirheumatic drug (bDMARD) and JAK inhibitor (JAKi) for the management of immune checkpoint inhibitors (ICI)-induced inflammatory arthritis. We aimed to assess their efficacy and safety in this setting. METHODS: Using the Club Rhumatismes and Inflammation French network, we conducted a multicentre, retrospective, observational study of patients with cancer diagnosed with inflammatory arthritis under ICI(s) and treated with bDMARD or JAKi. Clinical data were collected using a standardised case report form. RESULTS: Twenty patients (60% men, median age 69.5 years) were included, with rheumatoid arthritis (RA)-like (n=16), polymyalgia rheumatica-like (n=2) or psoriatic arthritis-like (n=2) clinical presentation. Two patients had pre-existing RA. 90% were treated with glucocorticoids as first-line therapy and 60% received methotrexate prior to bDMARD or JAKi. Anti-interleukin-6 receptor (IL-6R) therapy was used in 13/20 patients (65%), leading to clinical improvement in 11/13 patients (85%), but one patient experienced intestinal perforation and cancer progression was noticed in 6/13 patients (46%). Tumour necrosis factor inhibitors were used in 5/20 patients (25%), with improvement in 4/5 patients (80%) and cancer progression was observed in 3/5 patients (60%). Two infections (diverticulitis and pneumonitis) were reported. Anakinra, baricitinib and ustekinumab were each used in one patient. Median duration of the bDMARD or JAKi was 17 weeks. CONCLUSION: Anti-IL-6R therapy is currently the most common strategy in patients with ICI-induced inflammatory arthritis and insufficient response to glucocorticoids and methotrexate, leading to improvement in >80%. Overall, cancer progression occurred in about half of patients and whether the bDMARD/JAKi impacted the tumour response remains to be determined.

Interleukin-1ß-Activated Microvascular Endothelial Cells Promote DC-SIGN-Positive Alternatively Activated Macrophages as a Mechanism of Skin Fibrosis in Systemic Sclerosis.

OBJECTIVE: To characterize the role of interleukin-1ß (IL-1ß) and microvascular endothelial cells (MVECs) in the generation of alternatively activated macrophages in the skin, and to explore their role in the development of skin fibrosis in patients with systemic sclerosis (SSc; scleroderma). METHODS: Conditioned medium prepared with MVECs purified from the skin of healthy donors and the skin of SSc patients was used to generate monocyte-derived macrophages. Flow cytometry, multiplex protein assessment, real-time quantitative polymerase chain reaction, and tissue immunofluorescence were used to characterize MVEC-induced polarization of alternatively activated macrophages. Coculture experiments were conducted to assess the role of MVEC-induced alternatively activated macrophages in fibroblast activation. Alternatively activated macrophages were characterized in the skin of healthy donors and SSc patients using multiparametric immunofluorescence and multiplex immunostaining for gene expression. Based on our in vitro data, we defined a supervised macrophage gene signature score to assess correlation between the macrophage score and clinical features in patients with SSc, using the Spearman's test. RESULTS: IL-1ß-activated MVECs from SSc patients induced monocytes to differentiate into DC-SIGN+ alternatively activated macrophages producing high levels of CCL18, CCL2, and CXCL8 but low levels of IL-10. DC-SIGN+ alternatively activated macrophages showed significant enhancing effects in promoting the production of proinflammatory fibroblasts and were found to be enriched in perivascular regions of the skin of SSc patients who had a high fibrosis severity score. A novel skin transcriptomic macrophage signature, defined from our in vitro findings, correlated with the extent of skin fibrosis (Spearman's r = 0.6, P = 0.0018) and was associated with early disease manifestations and lung involvement in patients with SSc. CONCLUSION: Our findings shed new light on the vicious circle implicating unabated IL-1ß secretion, MVEC activation, and the generation of DC-SIGN+ alternatively activated macrophages in the development of skin fibrosis in patients with SSc.

Risk of diverticulitis and gastrointestinal perforation in rheumatoid arthritis treated with tocilizumab compared to rituximab or abatacept.

OBJECTIVE: To compare the risk of diverticulitis and gastrointestinal perforation (GIP) in RA treated with tocilizumab (TCZ) compared with rituximab (RTX) and abatacept (ABA). METHODS: We conducted a population-based study using three observational French registries on TCZ, RTX and ABA in RA. Using a propensity score approach, we compared the risk of diverticulitis or GIP in these patients. RESULTS: With inverse probability weighting, there was an increased risk of diverticulitis in TCZ-treated patients compared with RTX- or ABA-treated patients [hazard ratio (HR)=3.1 (95% CI: 1.5, 6.3), P =0.002]. Moreover, patients treated with TCZ had also an increased risk of GIP due to diverticulitis compared with those treated with RTX or ABA [HR=3.8 (1.1-13.6), P =0.04], resulting in an overall increased risk of GIP [HR=2.9 (1.1-7.8), P =0.03], while no significant increased risk of GIP due to any other aetiology was found in TCZ treated patients. Diverticulitis and GIP occurred earlier with TCZ than other drugs after the last perfusion (P =0.01), with atypical clinical presentation (slow transit in 30%, P =0.04) and lower acute-phase reactants at the time of the event (P =0.005). CONCLUSION: TCZ for RA was associated with increased odds of diverticulitis as well as GIP due to diverticulitis as compared with RTX and ABA. Our study confirms the increased odds of GIP in patients receiving TCZ, which might be explained by an increased risk of diverticulitis with misleading clinical presentation.

The response to TNF blockers depending on their comparator in rheumatoid arthritis clinical trials: the lessebo effect, a meta-analysis.

OBJECTIVE: To compare the effect of the biological reference agents (infliximab, etanercept, adalimumab) in RA in pivotal superiority placebo-controlled trials (reference agent vs placebo) vs their effect in equivalence active comparator-controlled trials (reference agent vs biosimilar). METHODS: The PubMed, EMBASE and Cochrane databases were searched for randomized, double-blind, controlled trials up to March 2020 comparing a biological reference agent vs placebo or biosimilar. The study assessed the ACR 20/50/70 responses of the reference agent in these groups (Reference-pbo and Reference-bs, respectively). The effect of the reference agent in both groups was estimated with 95% CI, pooled using random-effects models and then compared using a meta-regression model. RESULTS: We included 31 trials. The main characteristics of the population (disease duration and activity, % seropositivity and methotrexate dose) of the population in both groups were similar. The meta-analysis found a better ACR20 response to the biological originator in the Reference-bs group with a global rate of 70% (95% CI, 66, 74) compared with 59% (95% CI, 55, 62) in the reference-pbo group (P =0.001). A significant difference was also found for ACR 50 [44% (95% CI, 39, 50) vs 35% (95% CI, 31, 39), respectively, P <0.01]. CONCLUSION: The effect of the reference biologic agent was better when compared with an active drug to a placebo. This could be linked to an increased placebo effect in active comparator-controlled studies or a nocebo effect in placebo-controlled studies. This effect can be called the lessebo effect.

Baseline co-medications may alter the anti-tumoural effect of checkpoint inhibitors as well as the risk of immune-related adverse events.

PURPOSE: As gut microbiota composition is an important determinant of response to immune checkpoint inhibitors (ICIs), we examined the effect of various co-medications known for their interaction with microbiota, when given at ICI initiation. PATIENTS AND METHODS: We identified patients with advanced cancer treated with ICI between May 2015 and September 2017 in our institution. Co-medications given within 1 month before or 1 month after the first administration of ICI were reviewed from medical records. Survival data were analysed with univariable Cox regression, and the combined effect of multiple factors was assessed with factor analysis of mixed data (FAMD). The impact of co-medications on immune-related adverse events (irAEs) occurrence was also assessed. RESULTS: A total of 635 patients were included. Psychotropic drugs (41%), proton pump inhibitors (PPIs; 38%), angiotensin-converting enzyme (ACE) inhibitors and/or angiotensin II receptor blockers (ARBs; 32%), glucocorticoids (26%), antibiotics (24%), statins (21%) and morphine (20%) were the most prescribed co-medications. Baseline use of antibiotics, glucocorticoids >10 mg/day, PPIs, psychotropic drugs, morphine and insulin was associated with significantly shortened overall survival and decreased tumour response, whereas coadministration of statins, ACEs and/or ARBs, non-steroidal anti-inflammatory drugs, aspirin and oral antidiabetic drugs did not impact patient outcomes. Treatments that altered the response to ICI were also associated with a decreased incidence of irAEs. FAMD revealed the respective weight of each factor or co-medication on the oncological outcomes. CONCLUSION: Co-medications must be carefully assessed at the time of ICI initiation and clinicians aware of their possible deleterious effect, notably for PPIs, glucocorticoids, antibiotics and psychotropic drugs.

MUC5B promoter variant rs35705950 and rheumatoid arthritis associated interstitial lung disease survival and progression.

BACKGROUND: The major risk factor for idiopathic pulmonary fibrosis (IPF), MUC5B rs35705950, was found to be associated with rheumatoid arthritis-associated interstitial lung disease (RA-ILD). Whilst the MUC5B rs35705950 T risk allele has been associated with better survival in IPF, its impact on RA-ILD prognosis remains to be determined. Our objective was to explore the influence of MUC5B rs35705950 on survival and progression in RA-ILD. METHODS: Through an international retrospective observational study, patients with RA-ILD were genotyped for the MUC5B rs35705950 variant and consecutive pulmonary function tests (PFTs) findings were collected. Longitudinal data up to a 10-year follow-up were considered and analyzed using mixed regression models. Proportional hazards and joint proportional hazards models were used to analyze the association of baseline and longitudinal variables with lung transplant-free survival. Significant progression of RA-ILD was defined as at least an absolute or relative 10% decline of forced vital capacity at 2 years from baseline. RESULTS: Out of 321 registered patients, 261 were included in the study: 139 women (53.3%), median age at RA-ILD diagnosis 65 years (interquartile range [IQR] 57 to 71), 151 ever smokers (59.2%). Median follow-up was 3.5 years (IQR 1.3 to 6.6). Mortality rate was 32% (95%CI 19 to 42) at 10 years. The MUC5B rs35705950 variant did not impact lung transplant-free survival (HR for the T risk allele carriers=1.26; 95%CI 0.61 to 2.62; P=0.53). Decline in pulmonary function at 2 years was not influenced by MUC5B rs35705950 (OR=0.95; 95%CI 0.44 to 2.05; P=0.89), irrespective of the HRCT pattern. CONCLUSION: In this study, the MUC5B rs35705950 promoter variant did not influence transplant- free survival or decline in pulmonary function in patients with RA-ILD.

TGFß promotes low IL10-producing ILC2 with profibrotic ability involved in skin fibrosis in systemic sclerosis.

OBJECTIVE: Innate lymphoid cells-2 (ILC2) were shown to be involved in the development of lung or hepatic fibrosis. We sought to explore the functional and phenotypic heterogeneity of ILC2 in skin fibrosis within systemic sclerosis (SSc). METHODS: Blood samples and skin biopsies from healthy donor or patients with SSc were analysed by immunostaining techniques. The fibrotic role of sorted ILC2 was studied in vitro on dermal fibroblast and further explored by transcriptomic approach. Finally, the efficacy of a new treatment against fibrosis was assessed with a mouse model of SSc. RESULTS: We found that ILC2 numbers were increased in the skin of patients with SSc and correlated with the extent of skin fibrosis. In SSc skin, KLRG1- ILC2 (natural ILC2) were dominating over KLRG1+ ILC2 (inflammatory ILC2). The cytokine transforming growth factor-ß (TGFß), whose activity is increased in SSc, favoured the expansion of KLRG1- ILC2 simultaneously decreasing their production of interleukin 10 (IL10), which regulates negatively collagen production by dermal fibroblasts. TGFß-stimulated ILC2 also increased myofibroblast differentiation. Thus, human KLRG1- ILC2 had an enhanced profibrotic activity. In a mouse model of SSc, therapeutic intervention-combining pirfenidone with the administration of IL10 was required to reduce the numbers of skin infiltrating ILC2, enhancing their expression of KLRG1 and strongly alleviating skin fibrosis. CONCLUSION: Our results demonstrate a novel role for natural ILC2 and highlight their inter-relationships with TGFß and IL10 in the development of skin fibrosis, thereby opening up new therapeutic approaches in SSc.

Selectins impair regulatory T cell function and contribute to systemic lupus erythematosus pathogenesis.

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by a loss of tolerance toward self-nucleic acids, autoantibody production, interferon expression and signaling, and a defect in the regulatory T (Treg) cell compartment. In this work, we identified that platelets from patients with active SLE preferentially interacted with Treg cells via the P-selectin/P-selectin glycoprotein ligand-1 (PSGL-1) axis. Selectin interaction with PSGL-1 blocked the regulatory and suppressive properties of Treg cells and particularly follicular Treg cells by triggering Syk phosphorylation and an increase in intracytosolic calcium. Mechanistically, P-selectin engagement on Treg cells induced a down-regulation of the transforming growth factor-ß axis, altering the phenotype of Treg cells and limiting their immunosuppressive responses. In patients with SLE, we found an up-regulation of P- and E-selectin both on microparticles and in their soluble forms that correlated with disease activity. Last, blocking P-selectin in a mouse model of SLE improved cardinal features of the disease, such as anti-dsDNA antibody concentrations and kidney pathology. Overall, our results identify a P-selectin-dependent pathway that is active in patients with SLE and validate it as a potential therapeutic avenue.