Itaconate reduces proliferation and migration of fibroblast-like synoviocytes and ameliorates arthritis models.

Fibroblast-like synoviocytes (FLS) play critical roles in rheumatoid arthritis (RA). Itaconate (ITA), an endogenous metabolite derived from the tricarboxylic acid (TCA) cycle, has attracted attention because of its anti-inflammatory, antiviral, and antimicrobial effects. This study evaluated the effect of ITA on FLS and its potential to treat RA. ITA significantly decreased FLS proliferation and migration in vitro, as well as mitochondrial oxidative phosphorylation and glycolysis measured by an extracellular flux analyzer. ITA accumulates metabolites including succinate and citrate in the TCA cycle. In rats with type II collagen-induced arthritis (CIA), intra-articular injection of ITA reduced arthritis and bone erosion. Irg1-deficient mice lacking the ability to produce ITA had more severe arthritis than control mice in the collagen antibody-induced arthritis. ITA ameliorated CIA by inhibiting FLS proliferation and migration. Thus, ITA may be a novel therapeutic agent for RA.

A case of tick-borne Yezo virus infection: Concurrent detection in the patient and tick.

A 76-year-old woman infected with Yezo virus (YEZV) developed liver dysfunction and thrombocytopenia following a tick bite. Despite the severity of her elevated liver enzymes and reduced platelet counts, the patient's condition improved spontaneously without any specific treatment. To our knowledge, this represents the first documented case where the YEZV genome was detected simultaneously in a patient's serum and the tick (Ixodes persulcatus) that bit the patient. This dual detection not only supports the hypothesis that YEZV is a tick-borne pathogen but also underscores the importance of awareness and diagnostic readiness for emerging tick-borne diseases, particularly in regions where these ticks are prevalent.

Potential therapies targeting metabolic pathways in systemic lupus erythematosus.

The pathophysiology of systemic lupus erythematosus (SLE) is multifactorial and involves alterations in metabolic pathways, including glycolysis, lipid metabolism, amino acid metabolism, and mitochondrial dysfunction. Increased glycolysis in SLE T cells, which is associated with elevated glucose transporter 1 expression, suggests targeting glucose transporters and hexokinase as potential treatments. Abnormalities in lipid metabolism, particularly in lipid rafts and enzymes, present new therapeutic targets. This review discusses how changes in glutaminolysis and tryptophan metabolism affect T-cell function, suggesting new therapeutic interventions, as well as mitochondrial dysfunction in SLE, which increases reactive oxygen species. The review also emphasizes that modulating metabolic pathways in immune cells is a promising approach for SLE treatment, and can facilitate personalized therapies based on individual metabolic profiles of patients with SLE. The review provides novel insights into strategies for managing SLE.

Significantly Delayed Development of Polyarthritis with Active Tenosynovitis after Possible Temporary Neutropenic Immune-Related Adverse Events Caused by Atezolizumab Treatment: A Novel Case Report.

Immune checkpoint inhibitors have drastically improved cancer treatment. However, they may induce immune-related adverse events (irAEs). Here, we report a case of significantly delayed rheumatic irAEs (Rh-irAEs) with prior possible temporary neutropenic irAEs in a patient with atezolizumab-treated non-small-cell lung cancer and its management. A man in his sixties received atezolizumab monotherapy as the sixth-line treatment. He experienced an infusion-related reaction (fever) during the first cycle. On day 22 of cycle 2, grade 4 neutropenia suddenly appeared, but it disappeared on the next day. Cycle 3 was initiated after seven days; the patient did not exhibit any symptoms for approximately 500 days. However, on day 534 (day 1 of cycle 21), the patient complained of pain in the shoulders, back, and wrists. On day 644, the shoulder and back pain worsened with obvious swelling of the fingers. We thus suspended treatment and consulted a rheumatologist. A diagnosis of polyarthritis with active tenosynovitis was made based on joint ultrasound and laboratory tests. Prednisolone 15 mg attenuated the symptoms, allowing suspension of analgesics; however, dose reduction from 15 mg/day was difficult because of symptom flares. Finally, iguratimod 25 mg twice daily was initiated on day 764; prednisolone was reduced to 10 mg without flares, and its dosage was slowly reduced to 5 mg/day. Although irAEs exhibit multisystem features, delayed development of polyarthritis with active tenosynovitis after possible temporary neutropenic irAEs is rare. Thus, irAEs need to be monitored for a long time in patients with suspected irAE development even if it appears transiently.

The chest CT signs for pulmonary veno-occlusive disease correlate with pulmonary haemodynamics in systemic sclerosis.

OBJECTIVE: Pulmonary arterial hypertension associated with systemic sclerosis (PAH-SSc) sometimes accompanies pulmonary veno-occlusive disease (PVOD). We aimed to reveal the relation between clinical signs of PVOD and severing of pulmonary vasculopathy in SSc. METHODS: This study comprised 52 consecutive SSc patients who had pulmonary haemodynamic abnormalities (mPAP > 20 mmHg, PVR > 2 W.U. or PAWP > 15 mmHg). The chest CT scan was evaluated in all patients. Patients were divided into two groups, the 0-1 group and the 2-3 group, according to the number of chest CT signs for PVOD, including 1) mediastinal lymph node enlargement, 2) thickened interlobular septal wall, and 3) ground glass opacity. Pulmonary haemodynamics, echocardiography and MRI-based cardiac function, pulmonary function, and serum biomarkers were compared between the two groups. RESULTS: Mediastinal lymph node enlargement, thickened interlobular septal wall, and ground glass opacity were observed in 11 (21%), 32 (62%), and 11 (21%) patients, respectively. The 2-3 group (n = 15) had higher mPAP (p= 0.02) while lower DLco/VA (p= 0.02) compared with the 0-1 group (n = 37). Other parameters, including PAWP, cardiac output, left ventricular ejection fraction, left atrial diameter, forced vital capacity, brain natriuretic peptide, and Krebs von den Lunge-6 were not different between the two groups. CONCLUSION: The CT signs for PVOD had positive correlation with mPAP but negative correlation with DLco in SSc patients, indicating that PAH-SSc may reflect a spectrum of pulmonary vascular disease that ranges from the pulmonary artery to the vein.

An Antiphospholipid Antibody Profile as a Biomarker for Thrombophilia in Systemic Lupus Erythematosus.

Despite recent advances in treatment and significant improvements in prognosis, thrombosis remains the major cause of death in systemic lupus erythematosus (SLE). Antiphospholipid antibodies (aPL) are the main triggers of thrombosis in patients with SLE, with a frequency of approximately 30-40%. Lupus anticoagulant, anticardiolipin, and anti-ß2-glycoprotein I antibodies, which are included in the criteria for antiphospholipid syndrome, and 'non-criteria' aPL such as anti-phosphatidylserine/prothrombin complex antibodies, are risk factors for thrombosis in patients with SLE. Multiple positivity for aPL is also associated with an increased risk of thrombosis, and scores calculated from aPL profiles can predict the risk of developing thrombosis. Although there is insufficient evidence for treatment, aPL-positive SLE patients should/may be treated with anticoagulants and/or low-dose aspirin as appropriate. This review summarises the evidence on the clinical significance of the aPL profile as a biomarker of thrombophilia in patients with SLE.

Subcutaneous Panniculitis-like T-cell Lymphoma Lacking Subcutaneous Tumor Mimicking Adult-onset Still's Disease.

We herein report a case of subcutaneous panniculitis-like T-cell lymphoma (SPTCL) resembling adult-onset Still's disease (AOSD). A 40-year-old woman presented with a fever, erythema, and painful subcutaneous nodules on the trunk. Laboratory data and a bone marrow analysis showed hemophagocytic syndrome. Although AOSD was suspected, based on a histopathological evaluation of the erythema, she was diagnosed with SPTCL. She was refractory to combination chemotherapy but achieved durable remission with cyclosporine monotherapy. Genetic testing revealed a homozygous HAVCR2 c.245A>G variant (rs184868814) that had caused NLRP3 inflammasome activation. SPTCL and AOSD share a pathogenesis in terms of NLRP3 inflammasome activation, so the clinical phenotype of SPTCL reasonably mimics AOSD.

Clinical and Hemodynamic Responses to Imatinib in Pulmonary Veno-Occlusive Disease/Pulmonary Capillary Hemangiomatosis: A Retrospective Pilot Study of Five Cases and Review of the Literature.

BACKGROUND: Pulmonary veno-occlusive disease (PVOD) and pulmonary capillary hemangiomatosis (PCH) are rare types of pulmonary arterial hypertension with dismal prognoses; there is no established medical treatment for these conditions. Possible efficacy of imatinib against these conditions has been reported in 15 cases; however, how and in whom imatinib is effective remain unknown. METHODS: We retrospectively evaluated clinical data from consecutive patients with PVOD/PCH treated with imatinib at our institution. The diagnosis of PVOD/PCH was established using the following criteria: pre-capillary pulmonary hypertension; diffusion capacity of the lung for carbon monoxide < 60%; and two or more high-resolution computed tomography findings of interlobular septal thickening, centrilobular opacities, and mediastinal lymphadenopathy. The dose of pulmonary vasodilators remained unchanged during the assessment of imatinib. RESULTS: The medical records of five patients with PVOD/PCH were reviewed. The patients were aged 67 ± 13 years, their diffusion capacity of the lung for carbon monoxide was 29 ± 8%, and their mean pulmonary artery pressure was 40 ± 7 mmHg. Imatinib was administered at 50-100 mg/day; consequently, the World Health Organization functional class improved in one patient. In addition, imatinib improved the arterial oxygen partial pressure in this and another patient (these two also experienced a decreased mean pulmonary artery pressure and pulmonary vascular resistance after imatinib usage). CONCLUSIONS: This study indicated that imatinib improves the clinical condition, including pulmonary hemodynamics, of some patients with PVOD/PCH. In addition, patients with a certain high-resolution computed tomography pattern or PCH-dominant vasculopathy may respond favorably to imatinib.

Itaconate ameliorates autoimmunity by modulating T cell imbalance via metabolic and epigenetic reprogramming.

Dysregulation of Th17 and Treg cells contributes to the pathophysiology of many autoimmune diseases. Herein, we show that itaconate, an immunomodulatory metabolite, inhibits Th17 cell differentiation and promotes Treg cell differentiation by orchestrating metabolic and epigenetic reprogramming. Mechanistically, itaconate suppresses glycolysis and oxidative phosphorylation in Th17- and Treg-polarizing T cells. Following treatment with itaconate, the S-adenosyl-L-methionine/S-adenosylhomocysteine ratio and 2-hydroxyglutarate levels are decreased by inhibiting the synthetic enzyme activities in Th17 and Treg cells, respectively. Consequently, these metabolic changes are associated with altered chromatin accessibility of essential transcription factors and key gene expression in Th17 and Treg cell differentiation, including decreased RORγt binding at the Il17a promoter. The adoptive transfer of itaconate-treated Th17-polarizing T cells ameliorates experimental autoimmune encephalomyelitis. These results indicate that itaconate is a crucial metabolic regulator for Th17/Treg cell balance and could be a potential therapeutic agent for autoimmune diseases.

Beneficial effects of nintedanib on cardiomyopathy in patients with systemic sclerosis: a pilot study.

OBJECTIVES: Nintedanib is an inhibitor of tyrosine kinases that has been shown to slow the progression of interstitial lung disease (ILD), including ILD associated with SSc. The aim of this study was to explore the effect of nintedanib on cardiomyopathy associated with systemic sclerosis (SSc). METHODS: Twenty consecutively hospitalized patients with SSc-ILD were enrolled and prospectively followed. The rate of change at 6 months in cardiac magnetic resonance (CMR) parametric mapping, including myocardial extracellular volume, was primarily evaluated. Other endpoints included changes in CMR functional parameters, echocardiographic parameters, modified Rodnan skin score, serum biomarkers and pulmonary function test. RESULTS: Nintedanib was administered in 10 patients, whereas the other 10 were treated without nintedanib or watched, according to ILD severity and progression. Baseline values of CMR parametric mapping were not different between the two groups. The rate of change at 6 months in myocardial extracellular volume was highly different, almost divergent, between the nintedanib group and the control group (-1.62% vs +2.00%, P = 0.0001). Among other endpoints, the change in right ventricular ejection fraction was significantly different between the two groups (P = 0.02), with a preferential change in the nintedanib group. CONCLUSION: Our data indicate beneficial signals of nintedanib on cardiomyopathy associated with SSc. The anti-fibrotic effect of nintedanib might not be limited to the lung.

Efficacy and safety of oral pulmonary vasodilators in pulmonary veno-occlusive disease.

Pulmonary veno-occlusive disease (PVOD) or pulmonary capillary hemangiomatosis (PCH) is a rare subtype of pulmonary hypertension with dismal prognosis. Limited data are available on the efficacy and safety of orally administered pulmonary vasodilators for PVOD/PCH. Whether and how systemic sclerosis (SSc) affects the clinical outcomes of PVOD/PCH is also unknown. This study aimed to determine the clinical and hemodynamic efficacy and safety of oral pulmonary vasodilators for PVOD/PCH and clarify the possible effects of SSc on the clinical presentation of PVOD/PCH. We retrospectively analyzed the clinical data of 15 patients with PVOD/PCH treated with oral pulmonary vasodilators in our department since 2001. Six of them had SSc. Oral pulmonary vasodilators were administered either as single agents (n = 10) or in combination (n = 5). Treatment improved the functional class of five patients, and pulmonary arterial pressure and pulmonary vascular resistance decreased by 10 ± 12 mmHg and 36 ± 19%, respectively (p < 0.05 for both, n = 13), whereas pulmonary edema developed in three patients. The mean survival was 3.9 years, and the 1- and 3-year survival rates were 93% and 65%, respectively. The clinical presentation, including survival, was similar between patients with and without SSc. In our PVOD/PCH cohort, oral pulmonary vasodilators caused pulmonary edema in 20% of patients, but more than 80% of patients experienced significant pulmonary vasodilatory effects, and the overall prognosis was better than that previously reported. SSc does not adversely affect the clinical outcomes of PVOD/PCH.

Phosphofructokinase P fine-tunes T regulatory cell metabolism, function, and stability in systemic autoimmunity.

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by defective regulatory T (Treg) cells. Here, we demonstrate that a T cell-specific deletion of calcium/calmodulin-dependent protein kinase 4 (CaMK4) improves disease in B6.lpr lupus-prone mice and expands Treg cells. Mechanistically, CaMK4 phosphorylates the glycolysis rate-limiting enzyme 6-phosphofructokinase, platelet type (PFKP) and promotes aerobic glycolysis, while its end product fructose-1,6-biphosphate suppresses oxidative metabolism. In Treg cells, a CRISPR-Cas9-enabled Pfkp deletion recapitulated the metabolism of Camk4-/- Treg cells and improved their function and stability in vitro and in vivo. In SLE CD4+ T cells, PFKP enzymatic activity correlated with SLE disease activity and pharmacologic inhibition of CaMK4-normalized PFKP activity, leading to enhanced Treg cell function. In conclusion, we provide molecular insights in the defective metabolism and function of Treg cells in SLE and identify PFKP as a target to fine-tune Treg cell metabolism and thereby restore their function.

The deacetylase SIRT2 contributes to autoimmune disease pathogenesis by modulating IL-17A and IL-2 transcription.

Aberrant IL-17A expression together with reduced IL-2 production by effector CD4+ T cells contributes to the pathogenesis of systemic lupus erythematosus (SLE). Here, we report that Sirtuin 2 (SIRT2), a member of the family of NAD+-dependent histone deacetylases, suppresses IL-2 production by CD4+ T cells while promoting their differentiation into Th17 cells. Mechanistically, we show that SIRT2 is responsible for the deacetylation of p70S6K, activation of the mTORC1/HIF-1α/RORγt pathway and induction of Th17-cell differentiation. Additionally, SIRT2 was shown to be responsible for the deacetylation of c-Jun and histones at the Il-2 gene, resulting in decreased IL-2 production. We found that the transcription factor inducible cAMP early repressor (ICER), which is overexpressed in T cells from people with SLE and lupus-prone mice, bound directly to the Sirt2 promoter and promoted its transcription. AK-7, a SIRT2 inhibitor, limited the ability of adoptively transferred antigen-specific CD4+ T cells to cause autoimmune encephalomyelitis in mice and limited disease in lupus-prone MRL/lpr mice. Finally, CD4+ T cells from SLE patients exhibited increased expression of SIRT2, and pharmacological inhibition of SIRT2 in primary CD4+ T cells from patients with SLE attenuated the ability of these cells to differentiate into Th17 cells and promoted the generation of IL-2-producing T cells. Collectively, these results suggest that SIRT2-mediated deacetylation is essential in the aberrant expression of IL-17A and IL-2 and that SIRT2 may be a promising molecular target for new SLE therapies.

Role of Glutaminase 2 in Promoting CD4+ T Cell Production of Interleukin-2 by Supporting Antioxidant Defense in Systemic Lupus Erythematosus.

OBJECTIVE: Glutaminase (GLS) isoenzymes GLS1 and GLS2 catalyze the first step of glutaminolysis. GLS1 is requisite for Th17 cell differentiation, and its inhibition suppresses autoimmune disease in animals, but the function of GLS2 is not known. The aim of this study was to investigate the role of GLS2 in CD4+ T cell function and systemic lupus erythematosus (SLE) pathogenesis. METHODS: We measured reactive oxygen species (ROS) levels, lipid peroxidation, and mitochondrial mass and polarization by flow cytometry, interleukin-2 (IL-2) production by a dual luciferase assay, and CpG DNA methylation of Il2 by a real-time polymerase chain reaction system. The impact of the overexpression of wild-type GLS1, wild-type GLS2, or mutated GLS2 at the PDZ domain-binding motif in CD4+ T cells was examined. Furthermore, GLS2 expression in CD4+ T cells from lupus-prone mice and patients with SLE was analyzed by Western blotting. RESULTS: GLS2, but not GLS1, reduced ROS levels and lipid peroxidation and restored mitochondrial function in T cells. GLS2 promoted IL-2 production through the demethylation of the Il2 promoter. Mutation of the PDZ domain-binding motif abated the ability of GLS2 to regulate IL-2 and ROS levels. In lupus-prone mice and patients with SLE, the expression of GLS2 was decreased in CD4+ T cells. Finally, GLS2 overexpression corrected ROS levels and restored IL-2 production by CD4+ T cells from lupus-prone mice and SLE patients. CONCLUSION: Our findings suggest that GLS2 has a crucial role in IL-2 production by CD4+ T cells by supporting antioxidant defense, and they offer a new approach to correcting IL-2 production by T cells in SLE.

Intertwined pathways of complement activation command the pathogenesis of lupus nephritis.

The complement system is involved in the origin of autoimmunity and systemic lupus erythematosus. Both genetic deficiency of complement components and excessive activation are involved in primary and secondary renal diseases, including lupus nephritis. Among the pathways, the classical pathway has long been accepted as the main pathway of complement activation in systemic lupus erythematosus. However, more recent studies have shown the contribution of factors B and D which implies the involvement of the alternative pathway. While there is evidence on the role of the lectin pathway in systemic lupus erythematosus, it is yet to be demonstrated whether this pathway is protective or harmful in lupus nephritis. Complement is being explored for the development of disease biomarkers and therapeutic targeting. In the current review we discuss the involvement of complement in lupus nephritis.

Novel susceptibility loci for steroid-associated osteonecrosis of the femoral head in systemic lupus erythematosus.

Osteonecrosis of the femoral head (ONFH) involves necrosis of bone and bone marrow of the femoral head caused by ischemia with unknown etiology. Previous genetic studies on ONFH failed to produce consistent results, presumably because ONFH has various causes with different genetic backgrounds and the underlying diseases confounded the associations. Steroid-associated ONFH (S-ONFH) accounts for one-half of all ONFH, and systemic lupus erythematosus (SLE) is a representative disease underlying S-ONFH. We performed a genome-wide association study (GWAS) to identify genetic risk factors for S-ONFH in patients with SLE. We conducted a two-staged GWAS on 636 SLE patients with S-ONFH and 95 588 non-SLE controls. Among the novel loci identified, we determined S-ONFH-specific loci by comparing allele frequencies between SLE patients without S-ONFH and non-SLE controls. We also used Korean datasets comprising 148 S-ONFH cases and 37 015 controls to assess overall significance. We evaluated the functional annotations of significant variants by in silico analyses. The Japanese GWAS identified 4 significant loci together with 12 known SLE susceptibility loci. The four significant variants showed comparable effect sizes on S-ONFH compared with SLE controls and non-SLE controls. Three of the four loci, MIR4293/MIR1265 [odds ratio (OR) = 1.99, P-value = 1.1 × 10-9)], TRIM49/NAALAD2 (OR = 1.65, P-value = 4.8 × 10-8) and MYO16 (OR = 3.91, P-value = 4.9 × 10-10), showed significant associations in the meta-analysis with Korean datasets. Bioinformatics analyses identified MIR4293, NAALAD2 and MYO16 as candidate causal genes. MIR4293 regulates a PPARG-related adipogenesis pathway relevant to S-ONFH. We identified three novel susceptibility loci for S-ONFH in SLE.

ADAM9 enhances Th17 cell differentiation and autoimmunity by activating TGF-ß1.

The a disintegrin and metalloproteinase (ADAM) family of proteinases alter the extracellular environment and are involved in the development of T cells and autoimmunity. The role of ADAM family members in Th17 cell differentiation is unknown. We identified ADAM9 to be specifically expressed and to promote Th17 differentiation. Mechanistically, we found that ADAM9 cleaved the latency-associated peptide to produce bioactive transforming growth factor ß1, which promoted SMAD2/3 phosphorylation and activation. A transcription factor inducible cAMP early repressor was found to bind directly to the ADAM9 promoter and to promote its transcription. Adam9-deficient mice displayed mitigated experimental autoimmune encephalomyelitis, and transfer of Adam9-deficient myelin oligodendrocyte globulin-specific T cells into Rag1-/- mice failed to induce disease. At the translational level, an increased abundance of ADAM9 levels was observed in CD4+ T cells from patients with systemic lupus erythematosus, and ADAM9 gene deletion in lupus primary CD4+ T cells clearly attenuated their ability to differentiate into Th17 cells. These findings revealed that ADAM9 as a proteinase provides Th17 cells with an ability to activate transforming growth factor ß1 and accelerates its differentiation, resulting in aberrant autoimmunity.

Calcineurin inhibitors for adult-onset Still's disease: a multicentre retrospective cohort study.

OBJECTIVES: To clarify the efficacy and safety of calcineurin inhibitors (CNI) for treating adult-onset Still's disease (AOSD). METHODS: This multicentre historical cohort study enrolled the consecutive patients with AOSD according to Yamaguchi classification criteria. The endpoints were set as the time from the initiation of treatment to events, the persistency rate of CNI and safety. Based on the recurrent event data analysis, these endpoints were evaluated for each event. We divided the events into two groups according to the treatment that included CNI or conventional therapy without CNI. RESULTS: One hundred seventy-eight patients with 247 events were analysed. CNI were predominantly used in 72 events with a recurrent history, typical skin rash, high ferritin levels, and/or severe complications such as macrophage activation syndrome, disseminated intravascular coagulation, serositis, meningitis. CNI led to a significantly longer event-free survival (hazard ratio: 0.57, 95% confidential interval: 0.32-0.99) after adjustment of concomitant medications. Subgroup analysis showed that CNI were effective for AOSD patients with high ALT level (hazard ratio: 0.11, 95% confidential interval: 0.02-0.59) and severe complications (hazard ratio: 0.11, 95% confidential interval: 0.01-0.94). The persistency rate of CNI was 71% at 5th year. Adverse events occurred more frequently in the CNI group (18% versus 8%, p=0.02); however, CNI did not involve in increased risk of adverse events, including nephrotoxicity, after adjustment (p=0.23). CONCLUSIONS: Our retrospective analysis suggested that CNI could be an effective and safe option for treating AOSD.

Incidence and risk of antiresorptive agent-related osteonecrosis of the jaw (ARONJ) after tooth extraction in patients with autoimmune disease.

INTRODUCTION: Antiresorptive agent-related osteonecrosis of the jaw (ARONJ) is a rare but serious complication in patients receiving antiresorprtive agents (AR). However, the incidence of ARONJ after tooth extraction in patients with autoimmune disease (AID) remains unclear. The present study aimed to clarify the high-risk population of ARONJ in patients with AID. MATERIALS AND METHODS: The study population comprised 232 patients treated with AR, AID or non-AID, who had undergone dental extraction from January 2011 to September 2017. The incidence and risk factors of ARONJ were analysed retrospectively. Additionally, the relationship between ARONJ and osteoporotic fracture (OF) and AR discontinuation during dental procedures was investigated. RESULTS: Of 232 patients, 10 developed ARONJ within 1 year of dental extraction. The incidence of ARONJ in patients with AID was higher than that in non-AID patients (2.0/100 person-year vs 0.5/100 person-year; p = 0.03). Among the AID patients, RA patients had strikingly high incidence of ARONJ (3.6/100 person-year). The incidence of neither ARONJ nor OF significantly differed between patients who continued and discontinued AR in the perioperative period. CONCLUSION: Patients with AID who undergo dental extraction are at high risk of ARONJ. Discontinuation of AR would not significantly contribute to reduce the incidence of ARONJ in those patients.

Anti-cyclic citrullinated peptide antibody titers decrease in rheumatoid arthritis patients treated with tocilizumab: A pilot study.

Objectives: To analyze the effects of tocilizumab on peripheral B-cell subpopulation and its ability to produce anti-cyclic citrullinated peptide (CCP) antibody in patients with rheumatoid arthritis (RA).Methods: Thirteen consecutive RA patients initiated with tocilizumab were enrolled in our prospective study. Anti-CCP antibody titers and clinical parameters were evaluated during treatment. Peripheral blood B-cell subsets were analyzed using flow cytometry according to the Human Immunology Project.Results: Disease activity was significantly improved and anti-CCP antibody titers significantly decreased at week 24 compared to baseline. The percentages of post-switch memory B cells in CD19+ cells transiently increased at week 12, but there was no significant difference in any of the investigated B-cell subpopulations at week 24 compared to baseline. The ratios of post-switch memory to naïve B cells (post-switch/naïve) correlated negatively with anti-CCP antibody titers regardless of the time-points.Conclusion: Our study indicated that tocilizumab has a potential to reduce anti-CCP antibody production presumably by affecting post-switch/naïve ratio, and that anti-CCP antibody titers reflect B-cell distribution/subpopulation. As anti-CCP antibodies are produced in lymph nodes or ectopic lymphoid structures in synovial tissues, not in circulation, transient increment of post-switch memory B cells after tocilizumab treatment may reflect the altered balance of B-cell distribution between circulation and arthritic joints, resulting in suppressed production of anti-CCP antibody in situ.