Calcium pyrophosphate crystal arthritis associated with immune checkpoint inhibitor successfully treated with intra-articular glucocorticoid: A case report.

Immune checkpoint inhibitors (ICIs) sometimes induce immune-related adverse events (irAEs), and arthritis is one of the irAE symptoms. Recently, crystal-induced arthritis, such as calcium pyrophosphate (CPP) crystal deposition disease and gout, has been reported to occur after ICI administration. However, the distinction between ICI-associated crystal arthritis and ICI-induced non-crystal arthritis is difficult because their symptoms are similar. Besides, optimal treatment for ICI-associated crystal arthritis has not been established. Here, we report a patient who developed CPP crystal arthritis twice after pembrolizumab (ICI) administration and was successfully treated with intra-articular glucocorticoid injection. He suffered arthritis and acute interstitial nephritis simultaneously after ICI administration. Musculoskeletal ultrasound of his affected joint suggests that his arthritis was crystal-induced arthritis, and arthrocentesis detected CPP crystal in synovial fluid. Thus, we diagnosed his arthritis as ICI-associated cystal arthritis. Therefore, our case encourages the use of musculoskeletal ultrasound in patients with arthritis after treatment with ICI because it may distinguish between ICI-associated crystal arthritis and ICI-induced non-crystal arthritis. Besides, ICI-associated crystal arthritis could be treatable by intra-articular glucocorticoid injection.

Short-term and long-term outcomes of patients with anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis.

OBJECTIVES: Anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive dermatomyositis (MDA5-DM) is a subtype of dermatomyositis characterized by frequent interstitial lung disease and reduced muscle involvement. This study aimed to determine the short-term and long-term outcomes of patients with MDA5-DM. METHODS: Information on baseline characteristics, treatments, and short-term and long-term outcomes of patients with MDA5-DM including survival, relapse, and the titer of anti-MDA5 antibody, was retrospectively collected. Descriptive statistics regarding clinical outcomes were calculated, and a comparison of clinical parameters between patients with and without relapse was performed. The short-term survival according to the use of Janus kinase inhibitors (JAKi) was also assessed. RESULTS: A total of 154 patients with MDA5-DM were included in the study. Forty patients (25.9%) died during the remission induction phase, with respiratory failure being the most common cause of mortality. Among the 114 patients who survived the remission induction phase, the 5-year cumulative survival and relapse-free survival rates were 96.8% and 77.4%, respectively, and 7.9% of patients achieved complete drug-free remission. Fifty-four patients achieved normalization of anti-MDA5 antibody titers and only two of them relapsed after normalization. In the severe patients, the 6-month survival rate became significantly higher after the emergence of the JAKi treatment compared with before its existence (p= 0.03). CONCLUSIONS: Although relapse often occurs, the long-term survival of MDA5-DM patients who survived the remission induction phase is generally favorable. The status of the anti-MDA5 antibody is associated with relapse. JAKi may improve the survival of refractory patients with severe MDA5-DM.

New therapies in anti-MDA5 antibody-positive dermatomyositis.

PURPOSE OF REVIEW: This review focuses on treatments for anti-MDA5 antibody-positive dermatomyositis (MDA5-DM), which is a subgroup of dermatomyositis and characterized by frequent rapidly progressive interstitial lung disease and the high mortality rate. Despite conventional immunosuppressive therapies, there are still refractory cases. Newer treatment options are needed. RECENT FINDINGS: The triple combination therapy (high-dose glucocorticoids, calcineurin inhibitor, and intravenous cyclophosphamide) improved patient survival compared to high-dose glucocorticoids and step-wise addition of the immunosuppressants. The triple therapy now has been widely used, but there are still refractory cases. In addition to the conventional-type immunosuppressants, recently the efficacy of Janus kinase inhibitors, biologic agents such as rituximab, plasma exchange, and polymyxin B perfusion for refractory MDA5-DM patients have been reported. However, the majority of those reports regarding new treatments are limited to case series, retrospective studies, and small single-arm studies. Adding antifibrotic drugs to immunosuppressive therapies might have some ancillary benefits. SUMMARY: Several new therapies for MDA5-DM patients have emerged, although the optimal use of those therapies is still unknown. Further research and evidence accumulation will be needed. It is also noted that the intensive immunosuppressive therapies are associated with the higher infection risk.

Epithelial cell-derived cytokine TSLP activates regulatory T cells by enhancing fatty acid uptake.

Epithelial cells control a variety of immune cells by secreting cytokines to maintain tissue homeostasis on mucosal surfaces. Regulatory T (Treg) cells are essential for immune homeostasis and for preventing tissue inflammation; however, the precise molecular mechanisms by which epithelial cell-derived cytokines function on Treg cells in the epithelial tissues are not well understood. Here, we show that peripheral Treg cells preferentially respond to thymic stromal lymphoprotein (TSLP). Although TSLP does not affect thymic Treg differentiation, TSLP receptor-deficient induced Treg cells derived from naïve CD4+ T cells are less activated in an adoptive transfer model of colitis. Mechanistically, TSLP activates induced Treg cells partially through mTORC1 activation and fatty acid uptake. Thus, TSLP modulates the activation status of induced Treg through the enhanced uptake of fatty acids to maintain homeostasis in the large intestine.

Efficacy and safety of dose escalation of tofacitinib in refractory anti-MDA5 antibody-positive dermatomyositis.

Anti-melanoma differentiation-associated protein 5 (MDA5) antibody-positive dermatomyositis (MDA5-DM) is frequently complicated with rapidly progressive-interstitial lung disease (RP-ILD). The prognosis of MDA5-DM with RP-ILD is mostly poor despite intensive treatment with a combination of high-dose glucocorticoids and single conventional immunosuppressants. It was reported that the triple therapy (high-dose glucocorticoids, cyclophosphamide and tacrolimus) was more effective than a combination of high-dose glucocorticoids and stepwise addition of immunosuppressants. In addition, the efficacy of tofacitinib 10 mg/day for MDA5-DM with RP-ILD refractory to the triple therapy was suggested. However, the effect of those therapies was evaluated only in comparison to the historical control. Moreover, more importantly, there are still refractory patients even if treated with those therapies. In this case series, we report six MDA5-DM cases with RP-ILD in which the dose of tofacitinib was increased from 10 mg to 20 mg/day due to poor response to the triple therapy, followed by tofacitinib 10 mg/day. Four of six patients improved after dose escalation of tofacitinib, while two non-responders died. All six patients developed at least one infection including five cases of cytomegalovirus reactivation, one pulmonary aspergillosis, one herpes zoster and one herpes simplex keratitis. These cases suggest that the dose escalation of tofacitinib can be an option for MDA5-DM patients refractory to 10 mg/day of tofacitinib and other immunosuppressants although the risk of infection is a concern. The risk-benefit balance of the dose escalation of tofacitinib should be carefully assessed in each case.

Update on eosinophilic granulomatosis with polyangiitis.

Eosinophilic granulomatosis with polyangiitis (EGPA) (formerly Churg-Strauss syndrome) is a rare form of anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitis characterized by eosinophil-rich granulomatous inflammation and small to medium-size vessel vasculitis associated with bronchial asthma and eosinophilia. Its rarity and unique features such as eosinophilic inflammation have delayed progress of research regarding EGPA for several years, compared to other forms of ANCA-associated vasculitis. However, recently, attention to EGPA as a research subject has been gradually increasing. To resolve problems in existing criteria for EGPA, new classification criteria for EGPA generated by a large international cohort will be launched and is being expected to accelerate future studies. Pathogenesis and roles of ANCA in EGPA are still largely unknown; however, it has been reported that glomerulonephritis is more frequent in ANCA-positive patients than in ANCA-negative patients, while heart failure is more frequent in ANCA-negative patients than in ANCA-positive patients. In addition, a recent genome-wide association study has suggested the presence of two genetically distinct subgroups of EGPA, which correspond to ANCA-positive and -negative subgroups. Although responses to glucocorticoids in EGPA are generally good, patients with EGPA often experience a relapse. Currently, there is no standard therapy for EGPA based on accumulation of clinical trial results. Recently, clinical benefits of mepolizumab for EGPA were proved by a randomized controlled trial and mepolizumab was approved for EGPA. In addition, various new drugs are under evaluation. To find optimal use of these drugs and to resolve unmet needs, such as relapse prevention, will be needed in future.

Helios Enhances Treg Cell Function in Cooperation With FoxP3.

OBJECTIVE: Helios+FoxP3+CD4+ (Helios+) Treg cells are believed to be involved in the regulation of various autoimmune diseases; however, the regulatory mechanisms underlying the development of Helios+ Treg cells remain uncertain. This study was undertaken to elucidate the regulatory mechanisms of Helios expression in CD4+ T cells and its roles in transforming growth factor ß (TGFß)-induced Treg cell function. METHODS: We examined the expression of Helios in CD4+ T cells in patients with rheumatoid arthritis by DNA microarray analysis before and after treatment with biologic agents. We also examined the effect of interleukin-6 (IL-6) and TGFß on Helios expression in CD4+ T cells in humans and mice. The effect of forced expression of Helios on murine induced Treg cell function was also examined. The role of FoxP3 in the induction and function of Helios was assessed by using CD4+ T cells from FoxP3-deficient scurfy mice. RESULTS: Tocilizumab, but not tumor necrosis factor (TNF) inhibitors or abatacept, increased Helios expression in CD4+ T cells in patients with a good response. IL-6 inhibited the TGFß-induced development of Helios+ induced Treg cells in both humans and mice. Both cell-intrinsic FoxP3 expression and TGFß signaling were required for Helios induction in murine induced Treg cells. The forced expression of Helios enhanced the expression of various Treg cell-related molecules and the suppressive function in murine induced Treg cells. Helios-mediated enhancement of the suppressive function of induced Treg cells was obvious in FoxP3-sufficient CD4+ T cells but not in FoxP3-deficient CD4+ T cells. CONCLUSION: Our findings indicate that Helios enhances induced Treg cell function in cooperation with FoxP3.

Sox5 and c-Maf cooperatively induce Th17 cell differentiation via RORγt induction as downstream targets of Stat3.

Stat3 signaling is essential for the induction of RORγt and subsequent Th17 cell differentiation. However, the downstream targets of Stat3 for RORγt expression remain largely unknown. We show here that a novel isoform of Sox5, named Sox5t, is induced in Th17 cells in a Stat3-dependent manner. In vivo, T cell-specific Sox5-deficient mice exhibit impaired Th17 cell differentiation and are resistant to experimental autoimmune encephalomyelitis and delayed-type hypersensitivity. Retrovirus-mediated induction of Sox5 together with c-Maf induces Th17 cell differentiation even in Stat3-deficient CD4(+) T cells but not in RORγt-deficient CD4(+) T cells, indicating that Sox5 and c-Maf induce Th17 cell differentiation as downstream effectors of Stat3 and as upstream inducers of RORγt. Moreover, Sox5 physically associates with c-Maf via the HMG domain of Sox5 and DNA-binding domain of c-Maf, and Sox5 together with c-Maf directly activates the promoter of RORγt in CD4(+) T cells. Collectively, our results suggest that Sox5 and c-Maf cooperatively induce Th17 cell differentiation via the induction of RORγt as downstream targets of Stat3.

Interleukin-21-producing c-Maf-expressing CD4+ T cells induce effector CD8+ T cells and enhance autoimmune inflammation in scurfy mice.

OBJECTIVE: FoxP3 induces Treg cells and prevents autoimmune diseases. However, the precise mechanisms of FoxP3 in the prevention of autoimmune diseases remain unknown. We undertook this study to determine the regulatory roles of FoxP3 in autoimmune inflammation by using FoxP3-mutant sf mice. METHODS: We characterized interleukin-21 (IL-21)- producing cells in sf mice. We examined the underlying mechanisms of enhanced IL-21 production in sf mouse CD4+ T cells. We examined the roles of IL-21 and CD8+ T cells in autoimmune inflammation in sf mice using IL-21 receptor (IL-21R)-deficient sf mice. RESULTS: IL-21-producing c-Maf+CD4+ T cells, which were distinct from Th17 cells, were increased in sf mice. Increased c-Maf expression was involved in enhanced IL-21 production in sf mouse CD4+ T cells. Experiments using bone marrow chimeric mice showed that lack of cell-extrinsic suppression by FoxP3+ Treg cells, but not cell-intrinsic defects in FoxP3 in sf mouse CD4+ T cells, was mainly involved in the development of IL-21-producing c-Maf+CD4+ T cells in sf mice. IL-21R deficiency prolonged survival and reduced multiorgan autoimmune inflammation in sf mice. Moreover, IL-21R deficiency decreased short-lived effector CD8+ T cells in the lung in sf mice. Furthermore, depletion of CD8+ T cells inhibited lung inflammation in sf mice, suggesting that CD8+ T cells are critical for inducing lung inflammation in sf mice. CONCLUSION: Unique IL-21-producing c-Maf+ CD4+ T cells develop in the absence of FoxP3+ Treg cells, induce short-lived effector CD8+ T cells, and enhance multiorgan autoimmune inflammation in sf mice.

Prediction of relapse after discontinuation of biologic agents by ultrasonographic assessment in patients with rheumatoid arthritis in clinical remission: high predictive values of total gray-scale and power Doppler scores that represent residual synovial inflammation before discontinuation.

OBJECTIVE: This prospective study aimed to determine whether the comprehensive ultrasonographic assessment of synovial inflammation predicts relapse after discontinuation of treatment with a biologic agent in patients with rheumatoid arthritis (RA) in clinical remission. METHODS: RA patients in clinical remission (Disease Activity Score in 28 joints [DAS28] <2.6) receiving treatment with a biologic agent who agreed to discontinue the treatment were recruited. Patients underwent a comprehensive ultrasound scan on 134 synovial sites in 40 joints and were prospectively followed up for 6 months. Physicians who evaluated the patients during the study period were blinded to the baseline ultrasound findings. RESULTS: Forty-two patients receiving either a tumor necrosis factor antagonist or tocilizumab were enrolled. Using the optimal cutoff values determined by receiver operating characteristic curve analysis, relapse rates were significantly higher in patients whose total ultrasound scores at discontinuation were high than in those whose total ultrasound scores were low (P < 0.001 for both total gray-scale and power Doppler scores), whereas the difference between high and low DAS28 was not statistically significant (P = 0.158 by log rank test). Positive and negative predictive values were 80.0% and 73.3% for the total gray-scale score and 88.9% and 74.2% for the total power Doppler score, respectively. CONCLUSION: In RA patients in clinical remission receiving treatment with a biologic agent, residual synovial inflammation determined by comprehensive ultrasound assessment predicted relapse within a short term after discontinuation of the treatment. Our data provide a rationale and groundwork to conduct a large-scale study for establishment of ultrasound-based strategies to optimize the period of treatment with a biologic agent.

Correlation of radiographic progression with the cumulative activity of synovitis estimated by power Doppler ultrasound in rheumatoid arthritis: difference between patients treated with methotrexate and those treated with biological agents.

OBJECTIVE: Our prospective study aimed to demonstrate that the cumulative synovial power Doppler (PD) ultrasound scores correlate with radiographic progression better than conventional measures in patients with rheumatoid arthritis (RA). We also investigated the difference between antirheumatic agents. METHODS: Sixty-nine patients with RA who had recently received either methotrexate (MTX; n = 23), tumor necrosis factor (TNF) antagonists (n = 28), or tocilizumab (TCZ; n = 18) were enrolled. Patients underwent clinical, laboratory, and ultrasonographic assessment at baseline, 12 weeks, and 24 weeks. Radiographic damage was evaluated using van der Heijde modified total Sharp score (TSS) at baseline and 24 weeks. RESULTS: Fifty-seven patients continued the same treatment regimen for 24 weeks and completed the study, and 21 patients (36.8%) showed radiographic progression during the study period. In all patients, ΔTSS significantly correlated both with cumulative 28-joint Disease Activity Score-C-reactive protein (DAS28-CRP; ρ = 0.342, p = 0.009) and cumulative total PD scores (ρ = 0.357, p = 0.006). In MTX-treated patients, cumulative total PD scores significantly correlated with ΔTSS (ρ = 0.679, p = 0.004), whereas cumulative DAS28-CRP did not (ρ = 0.487, p = 0.056). However, cumulative total PD scores did not correlate with ΔTSS in TNF antagonist-treated or TCZ-treated patients. CONCLUSION: Our data confirm the evidence that synovial PD activity more accurately reflects active synovial inflammation (which actually causes joint destruction) than do conventional measures in patients treated with MTX. Our data also indicate that TNF antagonists can inhibit short-term radiographic progression in the presence of active synovitis.

[18F]FDG uptake in proximal muscles assessed by PET/CT reflects both global and local muscular inflammation and provides useful information in the management of patients with polymyositis/dermatomyositis.

OBJECTIVE: This study aimed to determine whether [(18)F]fluorodeoxyglucose-PET/CT ([(18)F]FDG-PET/CT) discriminates PM/DM from non-muscular diseases and also whether FDG uptake in proximal muscles reflects the activity and severity of muscular inflammation in PM/DM. METHODS: Twenty treatment-naïve PM/DM patients who underwent [(18)F]FDG-PET/CT were retrospectively identified by reviewing medical records. The same number of age- and sex-matched control patients with non-muscular diseases were also identified. Standardized uptake value (SUV) was calculated for each of the seven proximal muscles. For patient-based assessment, mean proximal muscle SUV was calculated by averaging the SUVs for these proximal muscles bilaterally. RESULTS: Mean proximal muscle SUVs were significantly greater in PM/DM patients than in control patients (median 1.05 vs 0.69, P < 0.001). Mean proximal muscle SUVs significantly correlated with mean proximal manual muscle test scores (ρ = 0.49, P = 0.028) and serum levels of creatine kinase (ρ = 0.54, P = 0.015) and aldolase (ρ = 0.64, P = 0.002). Furthermore, SUVs in proximal muscles from which biopsy specimens were obtained significantly correlated with histological grade for inflammatory cell infiltration (ρ = 0.66, P = 0.002). CONCLUSION: Our results suggest that [(18)F]FDG-PET/CT is useful in the diagnosis of PM/DM when inflammation in proximal muscles is globally assessed with quantitative measurements. Our results also indicate that local FDG uptake in a proximal muscle reflects the activity of inflammation in the same muscle and provides useful information in determining the region for muscle biopsy.

Assessment of acute injuries and chronic intimal thickening of the radial artery after transradial coronary intervention by optical coherence tomography.

AIMS: Transradial coronary intervention (TRI) introduces a trauma to the radial artery (RA), possibly influencing quality as a bypass conduit if subsequently used. We sought to determine the acute and chronic effects of TRI on the RA by optical coherence tomography (OCT). METHODS AND RESULTS: Immediately after TRI completion, 73 RAs in 69 patients were examined. The sheath was pulled back 2 cm distal to the puncture site, and OCT imaging was performed. The acute injuries and intimal thickening were compared between first-TRI RAs and repeat-TRI RAs. Intimal tears were observed in 49 RAs (67.1%) and were more frequent in the distal than in the proximal RA (P = 0.001). Medial dissections were not uncommon (26 RAs, 35.6%). The frequency of acute injury was significantly higher in repeat-TRI RAs (P < 0.001). Intima/medial area, the maximum intimal thickness/medial thickness ratio, and per cent narrowing were all significantly greater in repeat-TRI RAs in the distal and proximal RA. Multivariate analysis revealed that a repeated TRI procedure was the only independent predictor of intimal thickening. CONCLUSION: Optical coherence tomography clearly demonstrated significant acute injuries and chronic intimal thickening of RA after TRI. Further study should evaluate the impact of these effects when TRI RAs are subsequently used as conduits, on long-term graft patency and on clinical outcomes after bypass surgery.