Branched chain amino acids in the treatment of polymyositis and dermatomyositis: a phase II/III, multi-centre, randomized controlled trial.

OBJECTIVES: To assess the efficacy and safety of branched chain amino acids (BCAAs) in the treatment of PM/DM prior to official approval of their use in Japan. METHODS: Treatment naïve adults with PM/DM were enrolled in a randomized, double-blind trial to receive either TK-98 (drug name of BCAAs) or placebo in addition to conventional treatment. After 12 weeks, patients with an average manual muscle test (MMT) score <9.5 were enrolled in an open label extension study for a further 12 weeks. The primary endpoint was the change of the MMT score at 12 weeks. The secondary endpoints were the clinical response and the change of functional index (FI). RESULTS: Forty-seven patients were randomized either to the TK-98 (n = 24) or placebo (n = 23) group. The changes of MMT scores at 12 weeks were 0.70 (0.19) [mean (s.e.m.)] and 0.69 (0.18), respectively (P = 0.98). Thirteen patients from the TK-98 group and 12 from the placebo group were enrolled in the extension study. The MMT scores in both groups improved similarly. The increase of the FI scores of the shoulder flexion at 12 weeks was significantly greater in the TK-98 group [27.9 (5.67) vs 12.8 (5.67) for the right shoulder flexion, and 27.0 (5.44) vs 13.4 (5.95) for the left shoulder; P < 0.05]. Frequencies of adverse events up to 12 weeks were similar. CONCLUSION: BCAAs showed no effect on the improvement of the muscle strength evaluated by MMT and the clinical response. However, they were partly effective for improving dynamic repetitive muscle functions. TRIAL REGISTRATION: UMIN-CTR Clinical Trial, https://center6.umin.ac.jp/, UMIN000016233.

Combining maintenance therapy with hydroxychloroquine increases LLDAS achievement rates in individuals with stable systemic lupus erythematosus.

BACKGROUND: Hydroxychloroquine (HCQ) has been positioned as an anchor drug for systemic lupus erythematosus (SLE). There is evidence supporting the benefits of HCQ; however, the effect of additional HCQ in maintenance therapy remains unclear. METHODS: Thirty patients with SLE who visited Juntendo University Hospital were receiving maintenance therapy before HCQ treatment and were able to complete more than 104 weeks of HCQ treatment were analyzed. Anti-DNA antibody titers, IgG and CH50 levels, the maintenance dose of corticosteroids, the SLE disease activity index (SLEDAI), and the achievement of the Lupus Low Disease Activity State (LLDAS) were evaluated at baseline and at 12, 24, 52, and 104 weeks after HCQ initiation. RESULTS: We observed improvements in the anti-DNA antibody titers, IgG and CH50 levels, maintenance dose of corticosteroids, and SLEDAI at week 104 relative to baseline. Moreover, the LLDAS achievement rate increased over time from 10% at baseline to 43% and 80% at week 52 and week 104, respectively. CONCLUSION: Two years of continuous HCQ treatment led to improvements in SLE disease activity and corticosteroid dose and an increase in LLDAS achievement, thereby demonstrating the significance of the maintenance dose of HCQ for the management of SLE.

First external validation of sensitivity and specificity of the European League Against Rheumatism (EULAR)/American College of Rheumatology (ACR) classification criteria for idiopathic inflammatory myopathies with a Japanese cohort.

OBJECTIVE: To externally validate the performance of the new European League Against Rheumatism (EULAR)/American College of Rheumatology (ACR) classification criteria set for idiopathic inflammatory myopathies (IIM) with a Japanese cohort. METHODS: This study included 420 IIM and 402 non-IIM cases. Probability of having IIM in each patient was calculated using the collected data set. The cut-off probability was set at 55%, as recommended by EULAR/ACR. Patients classified as IIM by the criteria were further subclassified with classification trees. RESULTS: When the probability cut-off was set at 55%, the sensitivity/specificity of the new criteria to diagnose IIM were 89.3%/91.0% in the total cohort, 88.1%/95.1% without muscle biopsy data and 90.4%/65.5% with biopsy data. The cohort included 12 overlap syndrome patients with biopsy data, who were included as non-IIM cases in accordance with traditional Japanese methods. When they were included in the IIM cases, the specificity in patients with biopsy increased to 74.4%. The sensitivity/specificity of the new criteria to diagnose polymyositis/dermatomyositis (PM/DM) plus juvenile and amyopathic DM in the Japanese cohort was 87.4%/92.4%, which were greater than those of the Tanimoto's criteria revised to enable classification of amyopathic DM (ADM) (71.2%/87.8%) and were comparable with those of Bohan & Peter's criteria to diagnose those diseases except for ADM (88.4%/88.3%). CONCLUSIONS: Our study externally validated high specificity of the new criteria for the first time, although with several limitations, including low percentage of child patients. The new criteria have higher sensitivity and/or specificity in classification of PM/DM than the previously reported criteria, demonstrating its usefulness for interethnic patients.

FcγRIIb on B Cells and Myeloid Cells Modulates B Cell Activation and Autoantibody Responses via Different but Synergistic Pathways in Lupus-Prone Yaa Mice.

C57BL/6 (B6).FcγRIIb-/- Yaa mice spontaneously develop lethal lupus nephritis. To define the cell type-specific role of FcγRIIb in Yaa-associated lupus, we established B cell- (CD19Cre Yaa), myeloid cell- (C/EBPαCre Yaa), and dendritic cell- (DC) (CD11cCre Yaa) specific FcγRIIb-deficient B6.Yaa mouse strains. CD19Cre Yaa mice developed milder lupus than B6.FcγRIIb-/- Yaa mice, indicating that FcγRIIb deficiency on B cells is not sufficient for the development of severe disease. Surprisingly, C/EBPαCre Yaa mice also showed autoantibody production and mild lupus similar to that in CD19Cre Yaa mice, whereas CD11cCre Yaa mice stayed disease free. These observations indicate that FcγRIIb deficiency in B cells and myeloid cells, but not DCs, contributes to the severe disease in B6.FcγRIIb-/- Yaa mice. Flow cytometric analysis showed that the frequency of peripheral Gr-1- but not Gr-1+ monocyte was increased in B6.FcγRIIb-/- Yaa and C/EBPαCre Yaa but not CD19Cre Yaa mice, suggesting a link between FcγRIIb deficiency on myeloid cells and the high frequency of Gr-1- monocytes. RNA sequencing revealed that compared with Gr-1+ monocytes, Gr-1- monocytes expressed higher levels of the B cell-stimulating cytokines BSF-3, IL-10, and IL-1ß, the DC markers CD11c, CD83, and Adamdec1, and the antiapoptotic factors Bcl2 and Bcl6. In conclusion, in Yaa-associated lupus nephritis, FcγRIIb on B cells and myeloid cells modulates B cell activation via different but synergistic pathways. Gr-1- monocytes are the most likely candidate myeloid cells involved.

Splicing variant of WDFY4 augments MDA5 signalling and the risk of clinically amyopathic dermatomyositis.

OBJECTIVES: Idiopathic inflammatory myopathies (IIMs) are a heterogeneous group of rare autoimmune diseases in which both genetic and environmental factors play important roles. To identify genetic factors of IIM including polymyositis, dermatomyositis (DM) and clinically amyopathic DM (CADM), we performed the first genome-wide association study for IIM in an Asian population. METHODS: We genotyped and tested 496 819 single nucleotide polymorphism for association using 576 patients with IIM and 6270 control subjects. We also examined the causal mechanism of disease-associated variants by in silico analyses using publicly available data sets as well as by in in vitro analyses using reporter assays and apoptosis assays. RESULTS: We identified a variant in WDFY4 that was significantly associated with CADM (rs7919656; OR=3.87; P=1.5×10-8). This variant had a cis-splicing quantitative trait locus (QTL) effect for a truncated WDFY4isoform (tr-WDFY4), with higher expression in the risk allele. Transexpression QTL analysis of this variant showed a positive correlation with the expression of NF-κB associated genes. Furthermore, we demonstrated that both WDFY4 and tr-WDFY4 interacted with pattern recognition receptors such as TLR3, TLR4, TLR9 and MDA5 and augmented the NF-κB activation by these receptors. WDFY4 isoforms also enhanced MDA5-induced apoptosis to a greater extent in the tr-WDFY4-transfected cells. CONCLUSIONS: As CADM is characterised by the appearance of anti-MDA5 autoantibodies and severe lung inflammation, the WDFY4 variant may play a critical role in the pathogenesis of CADM.

Evaluation of the alternative classification criteria of systemic lupus erythematosus established by Systemic Lupus International Collaborating Clinics (SLICC).

OBJECTIVE: To evaluate the performance of the 2012 Systemic Lupus International Collaborating Clinics criteria (SLICC-12) on classifying systemic lupus erythematosus (SLE) in an uncontrolled multi-centered study with real-life scenario of the patients in Japan. METHODS: This study comprised 495 patients with SLE or non-SLE rheumatic diseases and allied conditions from 12 institutes in Japan. Chart review of each patient was performed by the 27 expert rheumatologists and diagnosis of 487 cases reached to the consensus. Value of the SLICC-12 on SLE classification was analyzed comparing with the 1997 revised American College of Rheumatology SLE classification criteria (ACR-97) employing the expert-consented diagnoses. RESULTS: Compared to the ACR-97, the SLICC-12 had a higher sensitivity (ACR-97 vs. SLICC-12: 0.88 vs. 0.99, p < .01) and comparable specificity (0.85 vs. 0.80). The rate of misclassification (0.14 vs. 0.11) or the area under the receiver operating characteristic curves (0.863 vs. 0.894) was not statistically different. In the cases that diagnoses corresponded in high rates among experts, both criteria showed high accordance of SLE classification over 85% with the expert diagnoses. CONCLUSION: Although employment of SLICC-12 for the classification for SLE should be carefully considered, the SLICC-12 showed the higher sensitivity on classifying SLE in Japanese population.

Disease flare patterns and predictors of systemic lupus erythematosus in a monocentric cohort of 423 Japanese patients during a long-term follow-up: The JUDE study.

OBJECTIVE: To clarify the clinical features of systemic lupus erythematosus (SLE) patients, factors associated with flares, and changes over time. METHODS: Patients having SLE with a visiting history were entered into the Juntendo University Database of Erythematosus. We included 423 cases in the long-term follow-up analysis, and 383 cases were followed for 10 years after the initiation of any therapeutic intervention (comparative analysis: 1973-1982, 82 cases; 1983-1992, 141, and 1993-2002, 160). We assessed changes in the patients' background characteristics, disease symptoms, flare rates, etc. RESULTS: Among the 423 cases, the mean follow-up period was 25.9 years, and mean number of flares was 0.51. Of those, 31.9% had ≥1 flares. Thrombocytopenia at onset contributed to the flares. For disease symptoms at onset, a recent trend in increasing thrombocytopenia was observed. The combination rate of immunosuppressive agents for diseases other than lupus nephritis was slightly increased, and there was no improvement until the first flare or in the flare rate. CONCLUSIONS: Thrombocytopenia at onset is predictive factor for flares. Since SLE is a diverse disease with varying symptoms at recurrence, the treatment guidelines should be improved for thrombocytopenia from a long-term perspective.

A genome-wide association study identified AFF1 as a susceptibility locus for systemic lupus eyrthematosus in Japanese.

Systemic lupus erythematosus (SLE) is an autoimmune disease that causes multiple organ damage. Although recent genome-wide association studies (GWAS) have contributed to discovery of SLE susceptibility genes, few studies has been performed in Asian populations. Here, we report a GWAS for SLE examining 891 SLE cases and 3,384 controls and multi-stage replication studies examining 1,387 SLE cases and 28,564 controls in Japanese subjects. Considering that expression quantitative trait loci (eQTLs) have been implicated in genetic risks for autoimmune diseases, we integrated an eQTL study into the results of the GWAS. We observed enrichments of cis-eQTL positive loci among the known SLE susceptibility loci (30.8%) compared to the genome-wide SNPs (6.9%). In addition, we identified a novel association of a variant in the AF4/FMR2 family, member 1 (AFF1) gene at 4q21 with SLE susceptibility (rs340630; P = 8.3×10(-9), odds ratio = 1.21). The risk A allele of rs340630 demonstrated a cis-eQTL effect on the AFF1 transcript with enhanced expression levels (P<0.05). As AFF1 transcripts were prominently expressed in CD4(+) and CD19(+) peripheral blood lymphocytes, up-regulation of AFF1 may cause the abnormality in these lymphocytes, leading to disease onset.

IL-6 signal blockade ameliorates the enhanced osteoclastogenesis and the associated joint destruction in a novel FcγRIIB-deficient rheumatoid arthritis mouse model.

OBJECTIVE: We earlier found that TNFα but not interleukin (IL)-17 is indispensable in the pathogenesis of spontaneously occurring rheumatoid arthritis (RA)-like disease in our newly established FcγRIIB-deficient C57BL/6 (B6) mouse model, designated KO1. Here, we examined the role of IL-6 in the pathogenesis of RA features in KO1, with particular reference to cartilage and bone destruction in arthritic joints. METHODS: To evaluate the preventive effect of MR16-1, a rat anti-mouse IL-6 receptor (IL-6R) mAb, 4-month-old preclinical KO1 mice were divided into three groups: the first treated with MR16-1 for 6 months, the second treated with normal rat IgG, as a control, and the third left untreated. The incidence and severity of arthritis, immunological abnormalities, and transcription levels of receptor activator of NF-κB ligand (RANKL), osteoprotegerin (OPG), and inflammatory cytokines/chemokines in ankle joint tissues were compared among the three groups. The therapeutic effect of MR16-1 was examined by treating 7-month-old KO1 mice in the early stages of arthritis for 2 months. RESULTS: Compared with the findings in the KO1 mice left untreated or treated with normal rat IgG, the development of arthritis was markedly suppressed in mice with MR16-1 treatment started from preclinical stages. The suppression was associated with the decrease in production of autoantibodies, rheumatoid factors (RF), and anti-cyclic citrullinated peptide (CCP). Histologically, marked synovitis, pannus formation, and cartilage and bone destruction associated with the increase in tartrate-resistant acid phosphatase (TRAP)-positive osteoclast generation were evident in the two control groups; however, these findings were virtually absent in MR16-1-treated mice. Real-time PCR analysis revealed that the up-regulated expression levels of MCP-1, IL-6, and TNFα, and the aberrantly high RANKL/OPG expression ratio in synovial joint tissues from the two control groups of mice with overt arthritis were significantly suppressed in MR16-1-treated mice. In mice with therapeutic MR16-1 treatment, there was no progression in arthritis score and the RANKL/OPG ratio in joint tissues was significantly suppressed. CONCLUSIONS: Administration of an anti-IL-6R mAb ameliorated spontaneously occurring RA-like disease features, indicating that IL-6, as well as TNFα, plays a pivotal role in the pathogenesis of RA in KO1 mice. Current studies showed that, in addition to the role in enhancing autoantibody production, IL-6 promotes synovial tissue inflammation and osteoclastogenesis, leading to the severe synovitis with pannus formation and the progressive cartilage and bone destruction in multiple joints.

Phenotype conversion from rheumatoid arthritis to systemic lupus erythematosus by introduction of Yaa mutation into FcγRIIB-deficient C57BL/6 mice.

We previously established an IgG Fc receptor IIB (FcγRIIB)-deficient C57BL/6 (B6)-congenic mouse strain (KO1), which spontaneously develops rheumatoid arthritis (RA), but not systemic lupus erythematosus (SLE). Here, we show that when Y chromosome-linked autoimmune acceleration (Yaa) mutation was introduced in KO1 strain (KO1.Yaa), the majority of KO1.Yaa mice did not develop RA, but instead did develop SLE. This phenotype conversion did not depend on autoantibody specificity, since KO1.Yaa mice, compared with KO1, showed a marked increase in serum levels of both lupus-related and RA-related autoantibodies. The increase in frequencies of CD69(+) activated B cells and T cells, and the spontaneous splenic GC formation with T follicular helper cell generation were manifest early in life of KO1.Yaa, but not KO1 and B6.Yaa, mice. Activated CD4(+) T cells from KO1.Yaa mice showed upregulated production of IL-21 and IL-10, compared with the finding in KO1 mice, indicating the possibility that this aberrant cytokine milieu relates to the disease phenotype conversion. Thus, our model is useful to clarify the shared and the disease-specific mechanisms underlying the clinically distinct systemic autoimmune diseases RA and SLE.