Efficacy of dupilumab and risk factors for dupilumab-induced hypereosinophilia in severe asthma: a preliminary study from China.

OBJECTIVE: Dupilumab has been approved for the treatment of severe asthma with type 2 inflammation by inhibiting interleukin (IL)-4 and IL-13 signaling. However, dupilumab-induced hypereosinophilia (HE) has been reported and should not be ignored. The aim of this study was to investigate the efficacy of dupilumab in Chinese patients with severe asthma, whether HE affects its efficacy, and the possible risk factors for HE. METHODS: 20 patients with severe asthma who received dupilumab treatment for at least 12 months in the First Affiliated Hospital of Guangzhou Medical University from 2019 to 2022 were included. We compared clinical data and laboratory tests results before dupilumab treatment and at 4 and 12 months after treatment. Based on whether dupilumab treatment triggers HE defined as blood eosinophil count (BEC) ≥ 1.5 × 109 cells/L, the patients were allocated into non-HE and HE groups. RESULTS: The patients showed a significant increase in asthma control test (ACT) scores, a decrease in the number of exacerbations, a decrease in the proportion of patients taking an oral corticosteroid (OCS) and in the dose, and a significant improvement in the pulmonary function parameters FEV1/FVC (%) and FEV1 (% predicted) after 4 and 12 months of treatment with dupilumab. For type 2 inflammatory biomarkers, the levels of fractional concentration of exhaled nitric oxide (FeNO), sputum eosinophil count percentage (SEC%) and total immunoglobulin E (TIgE) decreased significantly, whereas BEC were higher after 4 months of treatment, but returned to baseline levels after 12 months. 8 patients (40%) developed asymptomatic HE after dupilumab, and the efficacy was not significantly different between the HE and non-HE groups. The earliest BEC elevation appeared at 1 month after treatment, but most of them declined after 6 months, and basically returned to the baseline level around 12 months of treatment. In addition, we further found that when patients had FeNO ≥ 60 ppb, food allergens positive and combined eosinophilic otitis media (EOM), their BEC increased significantly more than that of the control group after 4 months as well as 12 months of treatment. CONCLUSIONS: This study demonstrated that dupilumab was efficacious in Chinese patients with severe asthma, and some patients developed asymptomatic, self-limited HE, which did not affect its efficacy. Additionally, FeNO ≥60 ppb, food allergens positive, and co-morbidities with EOM may be the risk factors for developing HE.

Lonicerin attenuates house dust mite-induced eosinophilic asthma through targeting Src/EGFR signaling.

Eosinophilic asthma is the predominant phenotype of asthma, and although these patients are sensitive to glucocorticoid therapy, they also experience many side effects. Lonicerin is a kind of bioflavonoid isolated from the Chinese herb Lonicera japonica Thunb, which has anti-inflammatory and immunomodulatory effects. The aim of this study was to elucidate the effects of lonicerin on eosinophilic asthma and its potential mechanisms. Here, we established a house dust mite (house dust mite)-induced eosinophilic asthma model in BALB/c mouse, and evaluated the effects of lonicerin on it. Our results showed that lonicerin significantly reduced airway hyperresponsiveness the number of inflammatory cells (especially eosinophils) and the elevation of interleukin (IL)-4, IL-5, IL-13 and eotaxin in bronchoalveolar lavage fluid (BALF) supernatants of mice. Additionally, lonicerin also eminently blunted inflammatory infiltration and mucus secretion, as well as mRNA levels of Mucin 5AC (MUC5AC) in lung tissue. Furthermore, results of network pharmacology and molecular docking revealed that Src kinase and epidermal growth factor receptor may be the potential targets responsible for the effects of lonicerin. Finally, in vivo experiments confirmed that lonicerin inhibited activation of the Src/EGFR pathway by decreasing their phosphorylation. Taken together, the present study demonstrated that lonicerin could suppress HDM-induced eosinophilic asthma in mice through inhibiting the activation of Src/EGFR pathway, which also provides a basis for further research as a new potentially therapeutic agent for eosinophilic asthma and its underlying mechanisms in the future.

[Diagnosis and Treatment of 43 Patients with IgG4-related Disease].

OBJECTIVE: To summarize the clinicopathological characteristics, diagnosis and treatment of IgG4-related disease (IgG4-RD). METHODS: The clinical data of 43 cases with IgG4-RD diagnosed from January 2013 to December 2017 were retrospectively analyzed. The clinical data of the patients including clinical characteristics, accessory examinations, diagnosis, and treatment were collected. RESULTS: Among the 43 patients with IgG4-RD, the ratio of male to female was 3∶1, the mean age was (51.3±15.9) years. Eleven patients had gastrointestinal symptoms, including 5 cases of IgG4-related cholangitis with the feature of dilation of the biliary system and narrowing of the lumen in the abdominal enhanced CT scans, and 6 cases of IgG4-related autoimmune pancreatitis with the feature of pancreatic enlargement or soft tissue density shadow in the abdominal enhanced CT scans. There were 10 cases (23.3%) with periorbital involvement, with the feature of intraorbital soft tissue nodule in the CT scan. Besides, 9 cases (20.9%) had lymphadenopathy, 6 cases (14.0%) had fever. The results of autoimmune antibody tests showed that 14 of 42 patients had increased antinuclear antibody (ANA). Among 40 patients who underwent immunoglobulin tests, 25 cases had elevated IgG, 12 cases had increased IgA, and 29 cases had increased IgE. Coombs test were performed for 6 cases and 4 patients were positive. Serum immunoglobulin G4 subtypes showed that the IgG4 levels of 35 patients were higher than 1 350 mg/L. The immunohistochemistry showed that IgG4 (+) cells (3->500/HPF) were infiltrated, with the CD20 (+), CD3ε (+) or CD138 (+). Among the 43 patients, 5 patients underwent operations due to misdiagnosis. All patients were treated with steroid and immunosuppressive agents after diagnosis, and their clinical symptoms were improved. CONCLUSION: The clinical symptoms of IgG4-RD are various, involving multiple organs. Therefore, the standardized diagnosis and treatment of IgG4-RD should be strengthened.

Successful closure of ileostomy in a patient with intestinal Behçet's disease after therapy with adalimumab: A case report.

RATIONALE: Behçet's disease (BD) is a chronic immune-mediated inflammatory disorder involving multiple organ systems. In BD, intestinal ulcers can present as a refractory lesion capable of perforation, which makes the choice of treatment difficult. PATIENT CONCERNS: A 34-year-old male who was diagnosed with intestinal BD and suffered with an ileocecal perforation. He underwent surgery for an ileostomy and was given corticosteroids as treatment. However, the ulcerative lesion remained resistant to the therapy that was provided which delayed the closure operation. DIAGNOSIS: Intestinal BD with severe post-operative complication. INTERVENTIONS: A course of adalimumab (ADa) therapy was started. Subsequently surgery was performed. And ADa and thalidomide were used as a maintenance therapy. OUTCOMES: In this case, a course of ADa therapy was given which healed the intestinal ulcers and allowed us to successfully perform the closure operation. LESSONS: This case indicates that ADa may be an effective treatment option in future cases, minimizing complications and allowing the closure operation to be performed successfully.

DEPTOR-mTOR Signaling Is Critical for Lipid Metabolism and Inflammation Homeostasis of Lymphocytes in Human PBMC Culture.

Abnormal immune response of the body against substances and tissues causes autoimmune diseases, such as polymyositis, dermatomyositis, and rheumatoid arthritis. Irregular lipid metabolism and inflammation may be a significant cause of autoimmune diseases. Although much progress has been made, mechanisms of initiation and proceeding of metabolic and inflammatory regulation in autoimmune disease have not been well-defined. And novel markers for the detection and therapy of autoimmune disease are urgent. mTOR signaling is a central regulator of extracellular metabolic and inflammatory processes, while DEP domain-containing mTOR-interacting protein (DEPTOR) is a natural inhibitor of mTOR. Here, we report that overexpression of DEPTOR reduces mTORC1 activity in lymphocytes of human peripheral blood mononuclear cells (PBMCs). Combination of DEPTOR overexpression and mTORC2/AKT inhibitors effectively inhibits lipogenesis and inflammation in lymphocytes of PBMC culture. Moreover, DEPTOR knockdown activates mTORC1 and increases lipogenesis and inflammations. Our findings provide a deep insight into the relationship between lipid metabolism and inflammations via DEPTOR-mTOR pathway and imply that DEPTOR-mTOR in lymphocytes of PBMC culture has the potential to be as biomarkers for the detection and therapies of autoimmune diseases.

Identification of Palmitoleic Acid Controlled by mTOR Signaling as a Biomarker of Polymyositis.

Polymyositis (PM) is a chronic disease characterized by muscle pain, weakness, and increase in muscle-related enzymes, accompanied with inflammations in lymphocytes. However, it is not well understood how the molecular alternations in lymphocytes contribute to the development of polymyositis. The mechanistic target of rapamycin (mTOR) signaling is the central regulator of metabolism and inflammation in mammalian cells. Based on previous studies, we proposed that mTOR signaling may control inflammatory reactions via lipid metabolism. In this study, we aim to figure out the role of mTOR signaling in the development of polymyositis and identify novel biomarkers for the detection and therapy of polymyositis. After screening and validation, we found that palmitoleic acid, a monounsaturated fatty acid, is highly regulated by mTOR signaling. Inhibition of mTORC1 activity decreases palmitoleic acid level. Moreover, mTORC1 regulates the level of palmitoleic acid by controlling its de novo synthesis. Importantly, increased palmitoleic acid has been proven to be a marker of polymyositis. Our work identifies palmitoleic acid in peripheral blood mononuclear cells (PBMC) as a biomarker of polymyositis and offers new targets to the clinical therapy.

mTOR complex 1 signalling regulates the balance between lipid synthesis and oxidation in hypoxia lymphocytes.

Mammalian cells adapt to different environmental conditions and alter cellular metabolic pathways to meet the energy demand for survival. Thus, the metabolic regulation of cells under special conditions, such as hypoxia, should be precisely regulated. During the metabolic regulation, mammalian target of rapamycin (mTOR) plays a vital role in the sensing of extracellular stimulations and regulating intracellular adaptations. Here, we report that mTOR complex 1 (mTORC1) signalling is a central regulator of lipid homoeostasis in lymphocytes. In hypoxia, mTORC1 activity is reduced and shifts lipid synthesis to lipid oxidation. Moreover, knockdown tuberous sclerosis complex 1 (TSC1) constitutively activates mTORC1 activity and impairs the hypoxia-induced metabolic shift. Therefore, TSC1 knockdown enhances hypoxia-induced cell death. Re-inactivation of mTORC1 activity via rapamycin may resist hypoxia-induced cell death in TSC1 knockdown lymphocytes. Our findings provide a deep insight into mTORC1 in the metabolic balance of lipid synthesis and oxidation, and imply that mTORC1 activity should be precisely regulated for the lipid homoeostasis in lymphocytes.

Pim-2/mTORC1 Pathway Shapes Inflammatory Capacity in Rheumatoid Arthritis Synovial Cells Exposed to Lipid Peroxidations.

Rheumatoid arthritis is a systemic autoimmune disease characterized by chronic inflammation of multiple joints, with disruption of joint cartilage. The proliferation of synovial fibroblasts in response to multiple inflammation factors is central to the pathogenesis of rheumatoid arthritis. Our previous studies showed that 4-HNE may induce synovial intrinsic inflammations by activating NF-κB pathways and lead to cell apoptosis. However, the molecular mechanisms of how synovial NF-κB activation is modulated are not fully understood. Here, the present findings demonstrated that 4-HNE may induce synovial intrinsic inflammations by mTORC1 inactivation. While ectopic activation of mTORC1 pathway by the overexpression of Pim-2 may disrupt the initiation of inflammatory reactions and maintain synovial homeostasis, our findings will help to uncover novel signaling pathways between inflammations and oxidative stress in rheumatoid arthritis development and imply that Pim-2/mTORC1 pathway may be critical for the initiation of inflammatory reactions in human rheumatoid arthritis synovial cells.

Association between Serum 25-Hydroxyvitamin D Level and Rheumatoid Arthritis.

The objective of this study is to examine and evaluate whether serum 25(OH)D is associated with disease activity in patients with rheumatoid arthritis (RA). Our results suggested that serum 25(OH)D in RA groups has significant lower level (35.99 ± 12.59 nmol/L) than that in the normal groups (54.35 ± 8.20 nmol/L, P < 0.05). Based on the DAS28, patients with RA were divided into four subgroups, and no differences were found in the four groups (P > 0.05). The 25(OH)D levels in complete remission, low disease activity, middle disease activity, and high disease activity group were 32.86 ± 12.26, 33.97 ± 13.28, 38.41 ± 10.64, and 38.94 ± 13.35 nmol/L, respectively. Based on the serum 25(OH)D levels, patients with RA were divided into inadequate group and normal group, and there were no significant differences in baseline characteristics and disease activity in the two groups. Our results showed that serum 25(OH)D levels in the inadequate group are significantly lower than those in the normal group. However, no correlations were found between 25(OH)D levels and disease activity among 116 patients with RA. The present findings will help to understand the association between 25(OH)D and disease activity of RA.

[Controlled clinical study on compound Decumbent Corydalis Rhizome and diclofenac in treatment of knee osteoarthritis].

To evaluate the efficacy and safety of compound Decumbent Corydalis Rhizome (DCR) in treating patients with knee osteoarthritis (OA). Totally 79 patients with knee osteoarthritis were selected from out-patient and inpatient departments of West China Hospital and randomly divided into the test group and the control group. The test group (n = 41) was given Compound DCR with the dosage of 1.8 g · d(-1), while the control group (n = 38) was administered with diclofenac sodium with the dosage of 75 mg · d(-1). After 12 weeks of treatment, the total efficacy rates based on patients/physicians evaluation for experimental and control groups were 68.29%, 63.41% and 71.05%, 63.16%, respectively, without significant difference between the two groups. Both of the two groups showed significant improvements in the main efficacy indexes (pain on walking 20 m) and minor indexes (tenderness on palpation, Western Ontario and McMaster Universities OA index (WOMAC) and Short-Form Health Survey (SF-36 ), but without significant difference in efficacy between them. The incidence of related adverse events was 24.39% in the test group and 47.37% in the control group, respectively, with significant differences between the two groups (P < 0.05). In the controlled study, compound DCR is as efficient as diclofenac sodium but more tolerable, with a good clinical application prospect.

[CCL19/IL-1beta positive feedback loop involved in the progress of inflammation in rheumatoid arthritis].

OBJECTIVE: To explore the function and mechanism of CCL19 in the pathogenesis of rheumatoid arthritis. METHODS: Synovial fibroblasts were collected from 5 cases of rheumatoid arthritis. Peripheral blood mononuclear cells (PBMCs) were obtained from 5 healthy people by Ficoll-Hypaque density gradien centrifugation. The cells were stimulated with IL-1beta, TNF-alpha, IL-17 and other cytokines, and then the expression of CCL19 was detected by RT-PCR. The cells also were treated with different concentration of CCL19, then the expressions of IL-1beta, TNF-alpha were detected by RT-PCR, the expressions of p-ERK, p-p38 were detected by western blot. RESULTS: IL-1beta promoted the CCL19/CCR7 expression in both synovial fibroblasts and PBMCs. CCL19 upregulated the expression of IL-10 in both synovial fibroblasts and PBMCs. The stimulation of CCL19 also increased its receptor CCR7 expression. CCL19 activated p-ERK and p-p38 in PBMCs. CONCLUSION: The positive feedback loop between CCL19 and IL-1 participate in the development of rheumatoid arthritis.

[Comparison of four assessment criteria for disease activity of rheumatoid arthritis].

OBJECTIVE: To compare of the efficacy of four assessment criteria for evaluating disease activity in rheumatoid arthritis. METHODS: Clinical data were collected from 172 patients ofrheumatoid arthritis. Disease activity was evaluated by four assessment criteria, which are disease activity score 28-C-reactive protein (DAS28-CRP), disease activity score 28-erythrocyte sedimentation rate (DAS28-ESR), simplified disease activity index (SDAI) and clinical disease activity index (CDAI). The patients were divided into four groups which were remission, low, middle and high disease activity. The correlations and consistencies among four methods were compared. RESULTS: Disease activities evaluated by four methods in 172 RA patients were significantly positive correlated (P<0.01). It was significantly consistent between SDAI and CDAI, also between DAS28-ESR and DAS28-CRP, the Kappa values were 0.949 and 0.862 respectively. The differences of the four methods in remission and high disease activity groups were no statistical significance. The proportion of the patients in low disease activity and middle disease activity groups evaluated by DAS28-ESR and DAS28-CRP were statistical different from that evaluated by CDAI and SDAI (P<0.05). CONCLUSION: Strong correlation was observed between the four methods. CDAI could be used to evaluate whether RA is remission or activity. For disease activity assessment, DSA28-ESR and DAS28-CRP seems superior to CDAI and SDAI.

[Disease activity and therapeutic strategy of patients with late-onset rheumatoid arthritis].

OBJECTIVE: To compare the disease activity and therapeutic strategy of late-onset rheumatoid arthritis (LORA) with young-onset rheumatoid arthritis (YORA). METHODS: Medical records of 259 patients with rheumatoid arthritis (RA) were reviewed retrospectively. The cut-off between LORA and YORA was operationally set at 60 years of age at disease onset. Gender ratio, disease duration, feature of involved joint, extra-articular features, laboratory features, disease activity score and treatment strategy were compared between LORA and YORA. RESULTS: The LORA patients had a gender ratio (male/female) of 1/1.88, which was approaching 1/1 in the older age group. It took longer for LORA to be diagnosed than YORA (P<0.001). LORA had more frequent involvement of shoulders (P < 0.001), while elbow, wrist, metacarpophalangeal joint ( MCP), proximal interphalangeal joint (PIP) and ankle joints were more common in YORA (P<0.001). LORA patients were more likely to have anemia than YORA patients (P<0.05). No significant differences were found between LORA and YORA in specific serologic index, including rheumatoid factor and anticyclic citrullinated peptide antibody, and disease activity score 28-C-reactive protein (DAS28-CRP) and clinical disease activity index (CDAI). But LORA had a higher simplified disease activity index (SDAI) (P=0.002). Glucorcoticoid was used in 67.4% LORA patients, compared with 29.3% in YORA patients (P<0.001). In contrast, disease-modifying anti-rheumatic drugs (DMARDs) were used in 73.7% LORA patients, compared with 97.6% in YORA patients (P<0.001). CONCLUSION: Delayed diagnose of LORA is common due to atypical presentation at disease onset. RA should be considered in elderly patients with large joints for differential diagnosis. LORA is more likely to have anemia than YORA, albeit no significant differences in serological index and extraarticular presentations. LORA patients should be treated with DMARDs as aggressively as YORA patients, if their comorbidities allow to do so.

Lipid peroxidation-mediated inflammation promotes cell apoptosis through activation of NF-κB pathway in rheumatoid arthritis synovial cells.

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by chronic inflammation of multiple joints. The central pathogenesis of RA is the proliferation of synovial fibroblasts in response to inflammatory cytokines. However, some of the targeted therapies for inflammation reactions do not display significant clinical improvement after initiation of therapy. Thus, the relationship between inflammatory responses and RA therapy is still incompletely understood. In the present study, we proposed to determine whether enhanced inflammations may lead to cell apoptosis in rheumatoid arthritis synoviocytes. Our results indicated that products of lipid peroxidations, 4-HNE, may induce synovial intrinsic inflammations by activating NF-κB pathways and it may lead to cell apoptosis. Pharmacological inhibition of NF-κB activation may reduce the 4-HNE mediated inflammation responses and subsequent cell apoptosis. Our results may help to clarify the role of inflammations on RA development and imply that blocking NF-κB activation may be partly beneficial for human RA therapy. These findings might provide a mechanism-based rationale for developing new strategy to RA clinical therapy.

[Comparison of four diagnostic criteria for idiopathic inflammatory myopathy].

OBJECTIVE: To compare the clinical values of four different criteria for diagnosing idiopathic inflammatory myopathy (IIM). METHODS: The four different criteria published in 1975, 1995, 1997 and 2004 were applied to 94 IIM patients and 98 patients with other myopathies in West China Hospital. RESULTS: The sensitivity of the four criteria for diagnosing IIM was 56. 4% (1975), 87. 2% (1995), 61.7 % (1997), and 52. 1% (2004) respectively. The specificity of the four criteria for diagnosing IIM was 78. 6% (1975), 20. 4% (1995), 78. 6% (1997), and 90. 8% (2004) respectively. The Youden index was 35.0% (1975), 7.6% (1995), 40. 3% (1997), and 42.9% (2004), with an odd product of 4. 74 (1975), 1. 75 (1995), 5. 91 (1997) and 10. 77 (2004) respectively. The Kappa value of the four criteria was 0. 351 (1975, P<0.05), 0. 075 (1995, P>0. 05), 0. 404 (1997, P<0.05 ) and 0. 433 (2004, P<0.05), and their area under the ROC curve was 0. 675 (1975, P=0. 00), 0. 538 (1995, P=0.36),0. 701 (1997, P=0.00) and 0. 715 (2004, P=0.00) respectively. CONCLUSION: The 2004 criteria have a better value in diagnosing IIM.

[Clinical features and risk factors associated with interstitial lung disease in patients with classic dermatomyositis or clinical amyopathic dermatomyositis].

OBJECTIVE: To investigate the clinical features and risk factors associated with interstitial lung disease (ILD) in patients with classic dermatomyositis (classic DM) or clinical amyopathic dermatomyositis (CADM). METHODS: Medical records of 121 DM patients (77 with classic DM and 44 with CADM) were reviewed retrospectively. The risk factors associated with ILD were identified through Binary Logistic Regression analyses. RESULTS: ILD presented in 40. 3% (31/77) of patients with classic DM and 50. 0% (22/44) of patients with CADM. Overall, the DM patients had a prevalence of ILD of 43. 8%. Univariate analyses showed that arthralgia, cough, dyspnea, anti-Jo-1 antibody, malignant tumors, and the levels of Erythrocyte sedimentation rate (ESR) and Albumin (ALB) were associated with ILD. The Multivariate Logistic Regression analysis identified arthralgia (beta= 1. 119, P= 0. 023), cough (beta= 2. 423, P= 0. 003) and ESR (beta= 0. 041, P= 0. 009) as risk factors of ILD. CONCLUSION: ILD is a common complication of classic DM/CADM and arthralgia, cough and high level of ESR are independent risk factors of ILD.

A clinical analysis of risk factors for interstitial lung disease in patients with idiopathic inflammatory myopathy.

Interstitial lung disease (ILD) is a common and severe complication of idiopathic inflammatory myopathies (IIM). The aim of our study was to identify risk factors for ILD by evaluating both clinical and biochemical features in IIM patients with or without ILD. From January 2008 to December 2011, medical records of 134 IIM patients in our rheumatology unit were reviewed. The patients were divided into ILD group (83 patients) and non-ILD group (51 patients). The clinical features and laboratory findings were compared. The univariable analyses indicated that arthritis/arthralgia (54.2% versus 17.6%, P < 0.05), Mechanic's hand (16.9% versus 2.0%, P < 0.05), Raynaud's phenomenon (36.1% versus 2.0%, P < 0.05), heliotrope rash (44.6% versus 19.6%, P < 0.05), fever (43.4% versus 21.6%, P < 0.05), elevated ESR (60.2% versus 35.3%, P < 0.05), elevated CRP (55.4% versus 31.4%, P < 0.05), or anti-Jo-1 antibody (20.5% versus 5.9%, P < 0.05) were risk factors for developing ILD in IIM. Multivariable unconditional logistic regression analysis that showed arthritis/arthralgia (OR 7.1, 95% CI 2.8-18.1), Raynaud's phenomenon (OR 29.1, 95% CI 3.6-233.7), and amyopathic dermatomyositis (ADM) (OR 20.2, 95% CI 2.4-171.2) were the independent risk factors for developing ILD in IIM.

Serum interleukin-6 expression level and its clinical significance in patients with dermatomyositis.

OBJECTIVE: To analyze serum interleukin-6 (IL-6) expression level and its clinical significance in patients with dermatomyositis. METHODS: Blood samples from 23 adult patients with dermatomyositis (DM), 22 with systemic lupus erythematosus (SLE), 22 with rheumatoid arthritis (RA), 16 with Sjögren's syndrome (SS), and 20 healthy controls were collected. The IL-6 concentration was detected by chemiluminescence immunoassay. Correlations between IL-6 expression levels and clinical features or laboratory findings in patients with DM were investigated. RESULTS: IL-6 expression level of DM patients was significantly higher than that of normal controls, significantly lower than that of RA patients, and slightly lower than that of SLE or SS patients with no significant differences. The incidence of fever was significantly higher in the IL-6 elevated group. Serum ferritin (SF) and C-reactive protein (CRP) were positively correlated with IL-6. CONCLUSIONS: IL-6 plays a less important role in DM than in RA. IL-6 monoclonal antibodies may have poor effect in patients with DM.