Efficacy and Safety of Biologics in Polymyalgia Rheumatica: A Retrospective Study.

INTRODUCTION: The study aimed to determine the efficacy and safety of biological disease-modifying antirheumatic drugs (bDMARDs) in the treatment of polymyalgia rheumatica (PMR) complicated by rheumatoid arthritis (RA). METHODS: Patients with PMR which could be classified as RA and who were treated with bDMARDs were included in the analysis. The primary endpoint was the clinical Polymyalgia Rheumatica Activity Score (Clin-PMR-AS) after 26 weeks of treatment, and the secondary endpoint was adverse events during the observation period. RESULTS: A total of 203 patients with PMR which was resistant or intolerant to glucocorticoids and could be classified as RA were receiving bDMARDs and were enrolled in the study. There were 83, 82, and 38 patients in the tumor necrosis factor inhibitor (TNFi), interleukin-6 receptor inhibitor (IL-6Ri), and cytotoxic T lymphocyte-associated antigen-4-immunoglobulin (CTLA4-Ig) groups, respectively. Twenty-six weeks after bDMARD initiation, Clin-PMR-AS levels were significantly lower in the IL-6Ri group as compared to other groups. Multiple regression analysis was performed with Clin-PMR-AS as the objective variable. Body mass index (BMI), history of bDMARDs, and IL-6Ri use were identified as factors involved in Clin-PMR-AS. After adjustment for group characteristics using inverse probability of treatment weighting with propensity scores, the Clin-PMR-AS score at 26 weeks was significantly lower in the IL-6Ri group (9.0) than in both the TNFi (12.4, p = 0.004) and CTLA4-Ig (15.9, p = 0.003) group. CONCLUSION: IL-6Ri may potentially improve the disease activity of PMR compared to other bDMARDs.

A case of Buerger's disease with vasculopathy and skin fibrosis requiring differential diagnosis from systemic sclerosis.

Buerger's disease is characterized by peripheral ischemia due to occlusion of small- and medium-sized arteries in the extremities. This report describes a case of Buerger's disease in a 51-year-old male who presented with findings resembling systemic sclerosis. The patient exhibited Raynaud's phenomenon in year X-3, which developed to skin hardening, nail avulsion, and ulceration of the right fingers in year X. Diagnostic testing showed positive microvasculopathy on nailfold videocapillaroscopy (NVC) and positive fibrosis on skin biopsy. Although the patient fulfilled the 2013 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) classification criteria for systemic sclerosis, several findings in this case were atypical for systemic sclerosis, including left-right asymmetry in finger involvement, nail loss, and negative autoantibody tests. Contrast-enhanced computed tomography showed poor perfusion of the right ulnar artery, and a heavy smoking history was established in the patient case. Therefore, based on Shionoya's criteria, he was diagnosed with a case of Buerger's disease confined to the upper extremity. Smoking cessation and vasodilator therapy resulted in the prompt resolution of ischemic symptoms, skin hardening, and ulcerations. Furthermore, NVC abnormalities improved, and ulnar artery occlusion showed reperfusion on repeat testing. The present case suggests that hypoxemia-driven microvasculopathy may contribute to vascular occlusion and skin fibrosis observed in this atypical presentation.

Predictors of functional improvement and pain reduction in rheumatoid arthritis patients who achieved low disease activity with disease-modifying antirheumatic drugs: a retrospective study of the FIRST Registry.

BACKGROUND: Rheumatoid arthritis (RA) patients sometimes exhibit different levels of improvement in health assessment questionnaire-disability index (HAQ-DI) and subjective pain visual analogue score (VAS) even after achieving low disease activities (LDA). This study aimed to identify factors associated with improvement in HAQ-DI and pain VAS among those who achieved LDA. METHODS: Data of the FIRST registry, a multi-institutional cohort of RA patients treated with biological and targeted-synthetic DMARDs (b/tsDMARDs) were analyzed. Patients who were enrolled from August 2013 to February 2023 and who achieved clinical LDA [clinical disease activity index (CDAI) ≤ 10.0] at 6 months after starting treatment were included. Multiple logistic regression analyses were conducted to identify the factors that associated with achieving HAQ-DI normalization (< 0.5), HAQ-DI improvement (by > 0.22), or pain VAS reduction (≤ 40 mm). RESULTS: Among 1424 patients who achieved LDA at 6 months, 732 patients achieved HAQ-DI normalization and 454 achieved pain VAS reduction. The seropositivity and the use of JAK inhibitor compared with TNF inhibitor were associated with both HAQ-DI < 0.5 and pain VAS reduction at 6 months. On the other hand, older age, past failure in ≥ 2 classes of b/tsDMARDs, higher HAQ-DI at baseline, and use of glucocorticoid were associated with the lower likelihood of HAQ-DI normalization and pain VAS reduction. Longer disease duration, being female, and higher disease activity at baseline was negatively associated HAQ-DI normalization alone. Comorbidities were not associated with the outcomes. CONCLUSIONS: These results suggest some preferable treatment may exist for improvement of HAQ-DI and pain VAS reduction in the early stage of the treatment, which is a clue to prevention of a criteria of difficult-to-treat RA.

Modifying T cell phenotypes using TYK2 inhibitor and its implications for the treatment of systemic lupus erythematosus.

OBJECTIVES: The tuning effects of JAK/TYK2 inhibitors on the imbalance between T follicular helper (Tfh) and T regulatory (Treg) cells, related to systemic lupus erythematosus (SLE) pathogenesis, were investigated using human peripheral blood samples. METHODS: Peripheral blood mononuclear cells from untreated patients with SLE and healthy controls were analysed. Tfh1 cells were identified in nephritis tissue, and the effect of Tfh1 cells on B-cell differentiation was examined by coculturing naïve B cells with Tfh1 cells. RESULTS: Tfh1 cell numbers were increased in the peripheral blood of patients, and activated Treg cell counts were decreased relative to Tfh1 cell counts. This imbalance in the Tfh to Treg ratio was remarkably pronounced in cases of lupus nephritis, especially in types III and IV active nephritis. Immunohistochemistry revealed Tfh1 cell infiltration in lupus nephritis tissues. Co-culture of Tfh1 cells (isolated from healthy individuals) with naïve B cells elicited greater induction of T-bet+ B cells than controls. In JAK/TYK2-dependent STAT phosphorylation assays using memory CD4+ T cells, IL-12-induced STAT1/4 phosphorylation and Tfh1 cell differentiation were inhibited by both JAK and TYK2 inhibitors. However, phosphorylation of STAT5 by IL-2 and induction of Treg cell differentiation by IL-2+TGFß were inhibited by JAK inhibitors but not by TYK2 inhibitors, suggesting that TYK2 does not mediate the IL-2 signalling pathway. CONCLUSIONS: Tfh1 cells can induce T-bet+ B cell production and may contribute to SLE pathogenesis-associated processes. TYK2 inhibitor may fine-tune the immune imbalance by suppressing Tfh1 differentiation and maintaining Treg cell differentiation, thereby preserving IL-2 signalling, unlike other JAK inhibitors.

CT informs detection and treatment options in rheumatoid arthritis complicated by pulmonary non-tuberculous mycobacterial disease from the FIRST registry.

OBJECTIVE: To investigate the early detection of pulmonary non-tuberculous mycobacterial (PNTM) disease by CT before the initiation of molecular-targeted therapeutic drugs in patients with rheumatoid arthritis (RA) and the efficacy and safety of combined treatment with antibiotics. METHODS: Patients with RA underwent chest CT before the introduction of molecular-targeted therapies in the Further Improvement of Rheumatoid arthritis Treatment registry. The primary endpoint was the number of patients who were detected by CT as having PNTM disease, complicating RA. RESULTS: Of 4447 patients with RA who underwent chest CT, 107 had suspected PNTM disease, and 33 diagnoses were confirmed by culture. In 14 of the 33 patients, plain radiographs showed no abnormalities; PNTM disease was only observed on CT scans. The prevalence of PNTM disease in patients with RA requiring molecular-targeted treatment was six times higher than that in healthy individuals. 31 patients initiated molecular-targeted therapeutic drugs in combination with anti-NTM treatment, and 28 were followed up for 24 months. No significant difference was observed in the retention rate and RA disease activity at 24 months between the PNTM and non-PNTM groups. Coexisting PNTM disease did not affect treatment discontinuation. None of the 28 patients in the PNTM group experienced exacerbation of PNTM disease. CONCLUSION: CT screening before the initiation of molecular-targeted treatment enabled the detection of asymptomatic PNTM that was undetectable on plain radiographs. This study showed that molecular-targeted therapeutic drugs in combination with anti-NTM treatment could control the disease activity of both PNTM and RA.

Comparison of anti-IL-6 receptor and JAK inhibitors in patients with rheumatoid arthritis from the real-world practice FIRST study.

OBJECTIVES: A molecular-targeted drug that is suitable as the second choice for patients with rheumatoid arthritis (RA) who show an inadequate response to the first biological disease-modifying antirheumatic drug (bDMARD) is unknown. This study aimed to analyze the efficacy and safety of interleukin-6 receptor (IL-6Ri) and Janus kinase inhibitors (JAKis), often selected as molecular-targeted drugs for second or subsequent treatments. METHODS: The efficacy and safety of JAKis and IL-6Ri were compared using propensity score-based inverse probability of treatment weighting (PS-IPTW) using propensity scores after 26 weeks of therapy in patients with RA. RESULTS: The remission rate at week 26, determined by the clinical disease activity index (CDAI), and the incidence of infection were higher in the JAKis than in the IL-6Ri group. The CDAI trajectories were divided into four according to the growth mixture modeling. IL-6Ri demonstrated greater efficacy in RA patients with ineffective to single bDMARD therapy compared with those with multiple ineffective bDMARDs. In patients who failed to respond to one bDMARD, there was no significant difference in the CDAI remission rate at week 26 between the JAKis (29.1%) and IL-6Ri (21.8%) groups (p= 0.21). However, for patients who did not respond to at least two bDMARDs, the CDAI remission rate at week 26 was higher in the JAKis than in the IL-6Ri group. CONCLUSIONS: IL-6Ri offers a superior balance of efficacy and safety compared with JAKis for RA patients unresponsive to one bDMARD. However, JAKis may suit patients who do not respond to multiple bDMARDs.

A Machine Learning Approach for Prediction of CDAI Remission with TNF Inhibitors: A Concept of Precision Medicine from the FIRST Registry.

INTRODUCTION: This study aimed to develop low-cost models using machine learning approaches predicting the achievement of Clinical Disease Activity Index (CDAI) remission 6 months after initiation of tumor necrosis factor inhibitors (TNFi) as primary biologic/targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs) for rheumatoid arthritis (RA). METHODS: Data of patients with RA initiating TNFi as first b/tsDMARD after unsuccessful methotrexate treatment were collected from the FIRST registry (August 2003 to October 2022). Baseline characteristics and 6-month CDAI were collected. The analysis used various machine learning approaches including logistic regression with stepwise variable selection, decision tree, support vector machine, and lasso logistic regression (Lasso), with 48 factors accessible in routine clinical practice for the prediction model. Robustness was ensured by k-fold cross validation. RESULTS: Among the approaches tested, Lasso showed the advantages in predicting CDAI remission: with a mean area under the curve 0.704, sensitivity 61.7%, and specificity 69.9%. Predicted TNFi responders achieved CDAI remission at an average rate of 53.2%, while only 26.4% of predicted TNFi non-responders achieved remission. Encouragingly, the models generated relied solely on patient-reported outcomes and quantitative parameters, excluding subjective physician input. CONCLUSIONS: While external cohort validation is warranted for broader applicability, this study highlights the potential for a low-cost predictive model to predict CDAI remission following TNFi treatment. The approach of the study using only baseline data and 6-month CDAI measures, suggests the feasibility of establishing regional cohorts to generate low-cost models tailored to specific regions or institutions. This may facilitate the application of regional/in-house precision medicine strategies in RA management.

This study aims to enhance the management of rheumatoid arthritis by predicting the likelihood of achieving the treatment target­Clinical Disease Activity Index remission within 6 months of initiating tumor necrosis factor inhibitors. In rheumatoid arthritis, the goal is often Clinical Disease Activity Index remission, and the standard approach involves using medications like methotrexate and biologic/targeted synthetic disease-modifying antirheumatic drugs. However, not all patients respond to these treatments, leading to a trial-and-error process of changing medications. Tumor necrosis factor inhibitors are commonly used as the initial biologic/targeted synthetic disease-modifying antirheumatic drugs for patients who do not respond adequately to methotrexate; however, tumor necrosis factor inhibitor treatment may not achieve effective outcomes for all patients. The study, using a cohort of patients with rheumatoid arthritis treated with tumor necrosis factor inhibitor, has developed a model predicting Clinical Disease Activity Index remission with tumor necrosis factor inhibitors. The models use only standard clinical parameters, therefore no special examination or additional cost is required for the predictions. This approach holds the potential to improve rheumatoid arthritis management by reducing the need for trial-and-error approaches and facilitating more personalized and effective treatment strategies. While further validation is necessary, the study also suggests that creating cost-effective models tailored to specific regions or institutions is possible.

Extracting immunological and clinical heterogeneity across autoimmune rheumatic diseases by cohort-wide immunophenotyping.

OBJECTIVE: Extracting immunological and clinical heterogeneity across autoimmune rheumatic diseases (AIRDs) is essential towards personalised medicine. METHODS: We conducted large-scale and cohort-wide immunophenotyping of 46 peripheral immune cells using Human Immunology Protocol of comprehensive 8-colour flow cytometric analysis. Dataset consisted of >1000 Japanese patients of 11 AIRDs with deep clinical information registered at the FLOW study, including rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). In-depth clinical and immunological characterisation was conducted for the identified RA patient clusters, including associations of inborn human genetics represented by Polygenic Risk Score (PRS). RESULTS: Multimodal clustering of immunophenotypes deciphered underlying disease-cell type network in immune cell, disease and patient cluster resolutions. This provided immune cell type specificity shared or distinct across AIRDs, such as close immunological network between mixed connective tissue disease and SLE. Individual patient-level clustering dissected patients with AIRD into several clusters with different immunological features. Of these, RA-like or SLE-like clusters were exclusively dominant, showing immunological differentiation between RA and SLE across AIRDs. In-depth clinical analysis of RA revealed that such patient clusters differentially defined clinical heterogeneity in disease activity and treatment responses, such as treatment resistance in patients with RA with SLE-like immunophenotypes. PRS based on RA case-control and within-case stratified genome-wide association studies were associated with clinical and immunological characteristics. This pointed immune cell type implicated in disease biology such as dendritic cells for RA-interstitial lung disease. CONCLUSION: Cohort-wide and cross-disease immunophenotyping elucidate clinically heterogeneous patient subtypes existing within single disease in immune cell type-specific manner.

Short-term effectiveness and safety of rituximab versus cyclophosphamide for life-threatening ANCA-associated vasculitis: a propensity score analysis of the real-world nationwide database.

OBJECTIVES: Life-threatening antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) with rapidly progressive glomerulonephritis (RPGN) and/or alveolar haemorrhage (AH) has a poor prognosis. Rituximab (RTX) is as effective as cyclophosphamide (CY) in remission induction therapy; however, the effectiveness and safety of RTX have not been established in life-threatening AAV. This study aimed to investigate the short-term effectiveness and safety of RTX in life-threatening AAV with RPGN and/or AH. METHODS: Between April 2018 and March 2020, cases treated with systemic glucocorticoids and RTX or intravenous CY (IVCY) was extracted from a Japanese nationwide inpatient database. Effectiveness was evaluated by in-hospital mortality and severe renal dysfunction requiring haemodialysis (HD) at discharge. Safety was evaluated by the in-hospital incidence of infections. The propensity score (PS) for RTX was estimated. Multivariable Cox and logistic regression with adjustment for PS were conducted to estimate the association of RTX with outcomes. RESULTS: From 16 001 612 hospitalised records, 687 life-threatening AAV cases were extracted. No significant difference in in-hospital mortality (adjusted HR 1.06; 95% CI 0.62 to 1.80) was found between the groups. Although the RTX group had a lower risk of fungal infections (adjusted OR (aOR) 0.45; 95% CI 0.23 to 0.84) and pneumocystis pneumonia (aOR 0.58; 95% CI 0.32 to 1.00), they might have an increased risk of severe renal dysfunction requiring HD at discharge (aOR 2.58; 95% CI 1.02 to 6.91). CONCLUSIONS: In life-threatening AAV, RTX has similar short-term effectiveness on mortality to IVCY. Although RTX might have a lower risk of fungal infections and pneumocystis pneumonia, the short-term renal prognosis might be inferior to IVCY.

Anti-survival motor neuron complex antibodies as a novel biomarker for pulmonary arterial hypertension and interstitial lung disease in mixed connective tissue disease.

OBJECTIVE: The presence of anti-U1 RNP antibodies (Abs) is critical for diagnosing MCTD. The aim of this study is to evaluate the clinical relevance of anti-survival motor neuron (SMN) complex Abs, which often coexist with anti-U1 RNP Abs. METHODS: A total of 158 newly diagnosed consecutive cases of SLE, SSc or MCTD with anti-U1 RNP Abs were enrolled in this multicentre observational study between April 2014 and August 2022. Serum anti-SMN complex Abs were screened by immunoprecipitation of 35S-methionine-labelled cell extracts, and associations between anti-SMN complex Abs positivity and clinical characteristics were analysed. RESULTS: Anti-SMN complex Abs were detected in 36% of MCTD patients, which was significantly higher than that in SLE (8%) or SSc (12%). Among MCTD patients classified based on the combination of the clinical features of SLE, SSc and idiopathic inflammatory myopathies, anti-SMN complex Abs showed the highest prevalence in a subset with clinical features of all three components. Anti-SMN complex Abs-positive MCTD had a higher prevalence of pulmonary arterial hypertension (PAH) and interstitial lung disease (ILD), which are related to poor prognosis, than negative patients. Moreover, all three cases of death within 1 year of the treatment were positive for anti-SMN complex Abs. CONCLUSIONS: Anti-SMN complex Abs is the first biomarker of a typical subset of MCTD which bears organ damages such as PAH and ILD.

A delayed diagnosis of fascioliasis: The importance of appropriate fecal diagnostic method.

Fascioliasis, a zoonotic helminthiasis, occurs sporadically in Japan. In this report, we describe a case of fascioliasis that was initially difficult to diagnose because the fecal examination method was negative for the Fasciola sp. eggs. A 64-year-old man living in Shimonoseki City, Japan, presented with fatigue and anorexia. Laboratory tests showed hepatic dysfunction and eosinophilia. Abdominal dynamic contrast-enhanced computed tomography and magnetic resonance cholangiopancreatography suggested intrahepatic biliary cysts. Thereafter, fever and night sweats persisted, and positron emission tomography and biopsy of the porta hepatis lymph node were performed on suspicion of malignancy. However, histopathological diagnosis found non-specific inflammation. As fascioliasis was suspected due to eosinophilia and the multiple hepatic masses, fecal egg examination was performed by an external private laboratory, which adopted the flotation method and reported the absence of parasite eggs. However, fecal examination was retried in our laboratory using the formalin-ether concentration method, and we detected Fasciola sp. eggs. This case suggests that misdiagnosis may occur depending on the fecal examination method; thus, it is necessary to choose a suitable method for certain parasite species.

Biological/targeted synthetic DMARDs do not arrest bone loss in patients with rheumatoid arthritis: a multicenter prospective observational study.

OBJECTIVE: To elucidate the differential effects of biological/target synthesized DMARDs (b/tsDMARDs) on bone metabolism in patients with rheumatoid arthritis (RA) in a real-world cohort. METHODS: This was a multicentre prospective observational study of RA patients enrolled at the time of 1st b/tsDMARDs administration. Bone mineral density (BMD) and bone turnover markers (BTMs) were measured during the 52-week observation. The study was designed to enrol all eligible RA patients. The end-points were differences in changes in BMD according to b/tsDMARD type, and the correlation between BMD and BTMs. RESULTS: A total of 1,164 patients were enrolled in this study. b/tsDMARDs improved RA disease activity from mean CDAI 25.5 at baseline to 4.5 at week 26. Patients not receiving anti-osteoporotic agents (anti-OP) at baseline with no history of fracture experienced a significant decrease in both femoral neck (F: mean 0.666-0.655 g/cm3) and radial (R: 0.518-0.514) BMD at week 26. Despite maintaining low CDAI levels during weeks 26-52 (5.3-4.4), there was a continued decline in BMD (F: 0.653, R: 0.509. Weeks 52). None of b/tsDMARDs type preserved BMD. Conversely, patients receiving anti-OP at baseline maintained stable BMD throughout the study (Weeks 0/26/52. F: 0.551/0.551/0.555, R: 0.415/0.416/0.415). Although BTMs were changed by b/tsDMARDs, the changes were unrelated to those in BMD. CONCLUSION: Our study suggested the progression of osteoporosis in RA patients during b/tsDMARDs treatment without anti-OP. BTMs may not reflect BMD change. Regular monitoring of BMD in RA should be considered for early management of osteoporosis.

Safety and efficacy of anifrolumab therapy in systemic lupus erythematosus in real-world clinical practice: LOOPS registry.

OBJECTIVES: To determine the safety and efficacy of anifrolumab in patients with systemic lupus erythematosus (SLE) classified based on the Lupus Low Disease Activity State (LLDAS) in real-world clinical practice. METHODS: This retrospective observational study involved SLE patients who started anifrolumab therapy. The primary end point was the retention rate over 26 weeks after initiating anifrolumab therapy; 45 patients followed up for 12 weeks or longer were analyzed in the following groups to determine the safety and efficacy up to week 12 after treatment initiation: 1) non-LLDAS achievement group and 2) minor flare group. Safety and efficacy were compared between the minor flare group and the standard of care (SoC) group (treated by adding glucocorticoids (GCs) or immunosuppressants) after adjustment with inverse probability of treatment weighting using propensity score (PS-IPTW). RESULTS: The retention rate of anifrolumab was 89.7% at week 26.The LLDAS achievement rates at week 12 were 42.9% and 66.7% in the non-LLDAS achievement and minor flare groups, respectively. In both groups, GC doses and SELENA-SLEDAI score significantly decreased. When the anifrolumab group with minor flare was compared with the SoC group or the GC dose increase group, the GC dose and SLEDAI score were significantly lower in the anifrolumab group than in both groups; there was no significant difference in LLDAS achievement. CONCLUSIONS: At week 26 after initiating anifrolumab therapy, ∼90% patients remained on therapy. Anifrolumab might lower disease activity without initiating GCs and reduce GC doses, especially in patients who experience minor flares after LLDAS achievement.

Generation-Dependent Retention Rates and Reasons for Discontinuation of Molecular Targeted Therapies in Patients with Rheumatoid Arthritis: From FIRST Registry.

INTRODUCTION: The study aimed to optimize medical care for elderly patients with rheumatoid arthritis (RA) by examining the 3-year continuation rate of different molecular targeted therapies across age groups in Japan, which has a significant elderly population. METHODS: The study included patients with RA who started molecular targeted therapies between 2013 and 2019 and divided them into three age groups. The primary outcome was to assess the 3-year continuation rate of each drug and analyze reasons for treatment discontinuation using inverse probability of treatment weighting. RESULTS: Among 2292 patients analyzed, tumor necrosis factor (TNF) inhibitors were most commonly used in those younger than 65 years of age (43.5%), while Janus kinase (JAK) inhibitors were also utilized (17.1%). In contrast, JAK inhibitors were less frequently used in patients aged 75 years and older (7.8%), with cytotoxic T lymphocyte antigen 4 immunoglobulin fusion proteins (CTLA4-Ig) being the most common (39.2%). JAK inhibitors and anti-interleukin-6 receptor (IL-6R) antibodies had higher continuation rates than other drugs in patients under 65 years (p < 0.001). For those aged 65-74 years, JAK inhibitors and CTLA4-Ig had higher continuation rates (p < 0.001), while among those aged 75 years and older, CTLA4-Ig and IL-6R antibodies had higher continuation rates (p < 0.001). Inadequate efficacy was the main reason for discontinuation in all age groups, while infection leading to discontinuation increased with age. CONCLUSIONS: The study highlights the need to consider different age groups separately in elderly RA care. Among patients aged 75 years and older, abatacept and anti-IL-6R antibodies showed the highest continuation rates, suggesting their potential suitability and efficacy for this specific age cohort.

Novel JAK inhibitors under investigation for systemic lupus erythematosus: - where are we now?

INTRODUCTION: Glucocorticoids and immunosuppressants are used to treat systemic lupus erythematosus (SLE). However, patients with SLE have poor long-term prognoses. This can be attributed to organ damage caused by flare-ups and drug toxicity due to the administration of nonspecific treatment. Therefore, SLE should be treated using therapeutic agents specific to its pathology. Janus kinase (JAK) inhibitors exert multitargeted effects by blocking the signaling of multiple cytokines. The use of JAK inhibitors has been approved to treat several inflammatory autoimmune diseases. Several clinical trials of JAK inhibitors for SLE treatment are ongoing. AREA COVERED: This review summarizes the basic and clinical significance of JAK inhibitors for treating SLE and the current status of the development of JAK inhibitors based on recent reports. EXPERT OPINION: SLE is a clinically and immunologically heterogeneous disease. Therefore, drugs targeting a single molecule require precision medicine to exert maximal therapeutic efficacy. JAK inhibitors can probably fine-tune the immune network via various mechanisms and broadly regulate complex immune-mediated pathologies in SLE. However, evidence is required to address some safety concerns associated with the use of JAK inhibitors in patients with SLE, including infections (particularly herpes zoster) and thromboembolism (particularly in the presence of concomitant antiphospholipid syndrome).

Differential expression of IFN-α, IL-12 and BAFF on renal immune cells and its relevance to disease activity and treatment responsiveness in patients with proliferative lupus nephritis.

OBJECTIVE: Since molecularly targeted therapies are emerging for treating lupus nephritis (LN), this study aimed to assess the immunohistochemical findings of the cytokines in renal tissue and their pathological and clinical relevance in LN. METHODS: Fifty patients with proliferative LN formed the case group; 5 with LN class II, IgA nephropathy and 10 with idiopathic haematuria were enrolled as controls. Immunohistochemical analysis for CD3, CD20, interferon (IFN)-α, interleukin (IL)-12/p40 and B-cell activating factor (BAFF) was performed by scoring the number of positive cells/area of the cortex. All immunohistochemical investigations were performed on formalin-fixed paraffin-embedded renal tissue. Proliferative LN cases were grouped by the dominant expression of IFN-α, IL-12/p40 and BAFF, and subsequently, clinicopathological features were compared. RESULTS: Clinical data of patients with proliferative LN included urine protein creatinine ratio, 2.2 g/gCre; anti-double-stranded DNA antibody, 200.9 IU/mL; total complement activity (CH50), 21.9 U/mL and SLE Disease Activity Index, 19.8 points. Proliferative LN cases, including class III (n=18) and IV (n=32), were classified into three subgroups according to the immunohistochemical score based on the dominancy of IFN-α (n=17), IL-12 (n=16) and BAFF group (n=17) proteins. Hypocomplementaemia and glomerular endocapillary hypercellularity were significantly increased in the IFN-α group, whereas chronic lesions were significantly higher in the IL-12 group (p<0.05). The IFN-α group had a poorer renal prognosis in treatment response after 52 weeks. CONCLUSIONS: The immunohistochemistry (IHC) of IFN-α, IL-12 and BAFF for proliferative LN enabled grouping. Especially, the IFN-α and IL-12 groups showed different clinicopathological features and renal prognoses. The results indicated the possibility of stratifying cases according to the IHC of target molecules, which might lead to precision medicine.

Immune Phenotype as a Biomarker for Systemic Lupus Erythematosus.

The treatment of rheumatoid arthritis was revolutionized with the use of molecular-targeted drugs that target immunoregulatory molecules. The success of treatment with these drugs prompted the development of molecular-targeted drugs for systemic lupus erythematosus. However, systemic lupus erythematosus is a disease with high heterogeneous immune abnormalities, and diverse cells or molecules can be treatment targets. Thus, the identification of subpopulations based on immune abnormalities is essential for the development of effective treatment. One analytical method used to identify subpopulations is the immunophenotyping of peripheral blood samples of patients. This analysis evaluates the validity of target molecules for peripheral blood immune cell subsets, which are expected to be developed as biomarkers for precision medicine in which appropriate treatment targets are set for each subpopulation.

Sustained remission following the discontinuation of tofacitinib in patients with rheumatoid arthritis (XANADU study): an open-label randomised study.

OBJECTIVE: To investigate sustained remission following the discontinuation of tofacitinib in patients with rheumatoid arthritis. METHODS: Patients who had an inadequate response to methotrexate (MTX) with or without biological disease-modifying antirheumatic drugs were randomly divided into two groups at baseline, and tofacitinib treatment in combination with MTX was administered to both groups. Either MTX or tofacitinib was then withdrawn if patients achieved Clinical Disease Activity Index remission at week 52. The primary outcome was the proportion of patients who sustained clinical remission at week 104. RESULTS: A total of 113 patients participated in this study. Among them, a total of 48 patients achieved remission at week 52. After discontinuation of tofacitinib, only 29.2% (7/24) of patients remained remission, while 50.0% (10/20) of patients, which was numerically higher but not statistically significant, sustained remission after MTX discontinuation. A greater proportion of bio-naïve patients achieved remission at week 52 and sustained low disease activity with tofacitinib discontinuation at week 104. Additionally, the patients who were able to discontinue tofacitinib without flares had lower rheumatoid factor (p=0.04) and lower anti-cyclic citrullinated peptide antibody (p=0.051) before discontinuation of tofacitinib. No severe adverse events were recorded after discontinuation of tofacitinib or MTX. In patients who relapsed after tofacitinib discontinuation, 71.4% achieved remission with resumption of tofacitinib. CONCLUSIONS: This study implies that a blanket cessation of tofacitinib may not be suitable for all patients, given that 58% of the participants experienced relapse. However, the withdrawal of tofacitinib is unlikely to result in the acquisition of treatment-resistance.

JAK inhibitors for rheumatoid arthritis.

INTRODUCTION: JAK (Janus kinase) is a type of non-receptor tyrosine kinase that includes JAK1, JAK2, JAK3, and Tyk2. Currently, there are five JAK inhibitors approved for treating rheumatoid arthritis. These inhibitors vary in their selectivity for different JAK isoforms. AREA COVERED: This review outlines the mode of actions and the results of Phase III trials of the JAK inhibitors which have been approved for the treatment of rheumatoid arthritis. EXPERT COMMENTARY: JAK inhibitors have the potential to finely tune immunity and inflammation in patients with rheumatoid arthritis. The in vitro data indicates that IL-6 signaling is suppressed by all JAK inhibitors, while tofacitinib exhibits the most extensive suppression of cytokines via the JAK pathway. Peficitinib suppresses common gamma cytokines, and filgotinib suppresses interferon. Furthermore, baricitinib and upadacitinib appear to be inclined toward suppressing interferon and the IL-12 family. Despite their specific target profiles, any of these drugs can inhibit other JAKs if their blood levels surpass a certain threshold. As a result, predicting in vivo selectivity remains a challenging task. JAK inhibitor seems to be a vital treatment option for difficult-to-treat rheumatoid arthritis patients, and it is expected that precision medicine approaches will enhance its effectiveness in the future.