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.

Relationships between Type 1 interferon signatures and clinical features of the new-onset lupus patients in Japan.

OBJECTIVES: The objective of the study is to investigate the relationships between Type 1 interferon (T1-IFN) signatures and clinical characteristics of lupus patients. METHODS: We examined 49 new-onset lupus patients who were diagnosed between 1999 and 2017. The patients treated with >10 mg of prednisolone or hydroxychloroquine were excluded from this study. Serum T1-IFN signatures were revealed by a functional reporter assay and standardized by recombinant IFN-α. Patient backgrounds, clinical findings, and treatments were retrospectively extracted from their electrical medical records. Clinical data were also available, including SLE Disease Activity Index of SLE patients on admission. RESULTS: T1-IFN signatures of lupus patients closely correlated with lupus disease activities, such as SLE Disease Activity Index-2K, white blood cell, C3 levels, and the titre of double-strand DNA antibody. We found fever and acute lupus dermatitis closely associated with T1-IFN signature. CONCLUSIONS: In lupus patients, fever and acute lupus dermatitis are good indicators of a strong T1-IFN signature.

Cluster analysis defines four groups of Japanese patients with adult-onset Still's disease.

OBJECTIVES: To define groups and characterize differences in the prognosis of patients with adult-onset Still's disease (AOSD). METHODS: We performed a retrospective cohort study. Patients with AOSD were grouped using hierarchical unsupervised cluster analysis according to age, sex, clinical features, and laboratory data. The primary endpoints were overall survival and drug-free remission rate. RESULTS: A total of 153 patients with AOSD were placed into four clusters. Those in Cluster 1 had a young onset, tended to be female, and had fewer complications and moderate ferritin concentrations. Those in Cluster 2 had a young onset and had more complications and higher ferritin concentrations. Those in Cluster 3 had a young onset, tended to be male, and had no lymphadenopathy and fewer complications. Those in Cluster 4 had an older onset, tended to be female, and had more complications and higher ferritin concentrations. Overall survival tended to be lower (P = .0539) in Cluster 4, and drug-free remission was higher in Clusters 1, 2, and 3 [hazard ratios (HRs) 2.19, 3.37, and 3.62 vs. Cluster 4, respectively]. CONCLUSIONS: Four groups of AOSD that have distinct clinical manifestations, ferritin concentrations, severity, and drug-free remission rate were identified, which were lowest in Cluster 4.

Influences of advanced age in rheumatoid arthritis: A multicentre ultrasonography cohort study.

OBJECTIVES: We aimed to evaluate the effects of age on clinical characteristics and outcomes in biologic or targeted synthetic disease-modifying antirheumatic drug (b/tsDMARD)-naïve patients with rheumatoid arthritis (RA). METHODS: We analysed the cases of 234 Japanese b/tsDMARD-naïve RA patients who underwent b/tsDMARD treatment in a multicentre ultrasound prospective observational cohort. We compared the clinical characteristics at baseline and outcomes at 12 months between those aged ≥60 years and those <60 years. RESULTS: Compared to the <60-year-old group (n = 78), the ≥60-year-old group (n = 156) had higher inflammatory marker values and ultrasound combined scores, especially wrist joints, at baseline. Age at baseline positively correlated significantly with the ultrasound scores at baseline; however, age was not a significant variable by the multiple regression analysis. The patients treated with different MOAs in the ≥60-year-old group had comparable outcomes and multiple regression analysis revealed that mechanism of action (MOA) was not a significant contributor to the Clinical Disease Activity Index at 12 months. CONCLUSIONS: RA patients with advanced age demonstrated distinctive clinical characteristics. The MOAs were not associated with clinical outcomes and ultrasound outcomes in RA patients with advanced age.

Usefulness of the severity classification for predicting drug-free remission in Japanese patients with adult-onset Still's disease.

OBJECTIVES: To investigate the usefulness of severity classification for predicting outcomes in patients with adult-onset Still's disease (AOSD). METHODS: This was a multi-centre retrospective cohort study. AOSD patients were classified into mild, moderate, and severe groups based on severity classification (Japanese Ministry of Health, Labour and Welfare) during the initial treatment, and clinical features were compared among these groups. The primary endpoints were the AOSD-related mortality and drug-free remission rate. For comparison, the same analysis was performed in parallel for patient groups stratified by the modified Pouchot systemic score. RESULTS: According to severity classification, 49 (35%), 37 (26%), and 56 patients (39%) were classified into mild, moderate, and severe groups, respectively. Patients in the severe group showed higher frequency of severe complications and the use of biological agents. Although AOSD-related survival was not significantly different (p = .0776), four of the five fatal cases were classified into the severe group. The severe group showed a reduced rate of drug-free remission (p = .0125). Patient groups classified by systemic score did not correlate with survival or drug-free remission. CONCLUSIONS: Severity classification is useful for predicting outcomes in patients with AOSD.

Association between serum bone biomarker levels and therapeutic response to abatacept in patients with rheumatoid arthritis (RA): a multicenter, prospective, and observational RA ultrasound cohort study in Japan.

BACKGROUND: To evaluate the effect of treatment on serum bone biomarkers and explore whether serum bone biomarkers are associated with therapeutic response in rheumatoid arthritis (RA) patients treated with abatacept. METHODS: We enrolled 59 RA patients treated with abatacept from a multicenter, exploratory, short-term, prospective and observational ultrasound cohort study of patients who received biologic or targeted synthetic disease-modifying antirheumatic drug (DMARD) therapy. We evaluated the patients' clinical disease activity and musculoskeletal ultrasound (MSUS) scores. The serum concentrations of five bone biomarkers were evaluated (dickkopf-1 [Dkk-1], sclerostin [SOST], osteocalcin [OC], osteopontin [OPN], and osteoprotegerin [OPG]) by multiplex bead assays at baseline, 3, and 6 months: the change over 6 months was defined as the Δ value. 'Power Doppler (PD) responder' was defined as a patient whose Δtotal PD score over 6 months was greater than the median change. RESULTS: Abatacept significantly improved the clinical disease activity and MSUS score over 6 months. Serum OPG was significantly elevated at 6 months after the abatacept introduction (p = 0.016). The ΔSOST and ΔOPG were significantly greater in the PD responders versus the non-PD responders (p = 0.0041 and 0.0073, respectively). The serum Dkk-1 at baseline was significantly lower in the PD responders (n = 30) vs. the non-PD responders (n = 29) (p = 0.026). A multivariate logistic regression analysis showed that the serum Dkk-1 at baseline (odds ratio 0.50, 95% confidence interval [CI] 0.23-0.91, p = 0.043) was an independent predictor of PD responder status. CONCLUSION: Serum levels of bone biomarkers may be useful for predicting RA patients' therapeutic responses to abatacept. TRIAL REGISTRATION: Name of the registry: Assessment of therapeutic responsiveness by imaging of the joints in patients with rheumatoid arthritis; A observational cohort study Trial registration number: UMIN000012524 Date of registration: 12/9/2013 URL of trial registry record: https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000014657.

Clinical features of elderly-onset Adult-onset Still's disease.

OBJECTIVES: To clarify the characteristics of patients with elderly-onset Adult-onset Still's disease (AOSD). METHODS: Patients were classified into elderly-onset (>60 years: 47 patients) and younger-onset (≤60 years: 95 patients) groups according to their age at diagnosis of AOSD. Clinical features, treatments, and prognosis were compared between the elderly-onset and younger-onset groups. RESULTS: In the elderly-onset group, compared with the younger-onset group, typical skin rashes were less frequent (21.3% vs 58.9%, respectively; p < .0001), whereas pleuritis (27.7% vs 7.4%, respectively; p = .0011) and disseminated intravascular coagulation (19.1% vs 2.1%, respectively; p = .0004) were more frequent, and serum ferritin levels were higher (median 12,700 ng/ml vs 2526 ng/ml, respectively; p < .0001). Overall survival and AOSD-related survival were reduced (p = .0006 and p = .0023, respectively) and drug-free remission was less frequent (p = .0035) in the elderly-onset group compared with the younger-onset group. CONCLUSIONS: Our results demonstrated that elderly-onset AOSD patients had several characteristics that differed from younger-onset AOSD patients, including less typical skin lesions, more AOSD-related complications, higher ferritin levels, and poorer prognoses.

Rituximab maintenance therapy for patients with antineutrophil cytoplasmic antibody-associated vasculitis in Japan.

OBJECTIVES: We examined the efficacy and safety of rituximab (RTX) maintenance therapy for patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) in Japan. METHODS: We conducted a retrospective study using a multi-center cohort database of vasculitis patients. All maintenance treatment courses were divided into three groups: a RTX group, a group treated with other immunosuppressant drugs (IS) and a group receiving glucocorticoid monotherapy (GC). The primary endpoint was the comparison of relapse-free survival after 1 year. We also analyzed the occurrence of severe adverse events (SAEs) to assess safety. RESULTS: We included 123 courses of 107 patients (RTX n = 14, IS n = 64, GC n = 45). Twelve of 14 in the RTX group patients were diagnosed with granulomatosis with polyangiitis (GPA). The relapse-free survival of RTX maintenance therapy was comparable to that in the other groups (p = .122). After 1 year of treatment, the RTX group was administered lower steroid doses and one-third of them could withdraw corticosteroid. The overall incidence of SAE was 0.54/patient-year in the RTX group, 0.39/patient-year in the IS group and 0.34/patient-year in the GC group. CONCLUSION: RTX maintenance therapy could be effective and safe in Japanese GPA patients.

Identification of lipophilic ligands of Siglec5 and -14 that modulate innate immune responses.

Sialic acid-binding immunoglobulin-like lectins (Siglecs) are a family of cell-surface immune receptors that bind to sialic acid at terminal glycan residues. Siglecs also recognize nonsialic acid ligands, many of which remain to be characterized. Here, we found that Siglec5 and Siglec14 recognize lipid compounds produced by Trichophyton, a fungal genus containing several pathogenic species. Biochemical approaches revealed that the Siglec ligands are fungal alkanes and triacylglycerols, an unexpected finding that prompted us to search for endogenous lipid ligands of Siglecs. Siglec5 weakly recognized several endogenous lipids, but the mitochondrial lipid cardiolipin and the anti-inflammatory lipid 5-palmitic acid-hydroxystearic acid exhibited potent ligand activity on Siglec5. Further, the hydrophobic stretch in the Siglec5 N terminus region was found to be required for efficient recognition of these lipids. Notably, this hydrophobic stretch was dispensable for recognition of sialic acid. Siglec5 inhibited cell activation upon ligand binding, and accordingly, the lipophilic ligands suppressed interleukin-8 (IL-8) production in Siglec5-expressing human monocytic cells. Siglec14 and Siglec5 have high sequence identity in the extracellular region, and Siglec14 also recognized the endogenous lipids. However, unlike Siglec5, Siglec14 transduces activating signals upon ligand recognition. Indeed, the endogenous lipids induced IL-8 production in Siglec14-expressing human monocytic cells. These results indicated that Siglec5 and Siglec14 can recognize lipophilic ligands that thereby modulate innate immune responses. To our knowledge, this is the first study reporting the binding of Siglecs to lipid ligands, expanding our understanding of the biological function and importance of Siglecs in the innate immunity.

The complete mitochondrial genome of Sarcoptes scabiei var. nyctereutis from the Japanese raccoon dog: Prediction and detection of two transfer RNAs (tRNA-A and tRNA-Y).

Sarcoptes scabiei (Acari: Sarcoptidae) causes a common contagious skin disease that affects many mammals. Here, the complete mitochondrial genome of a mite, S. scabiei var. nyctereutis, from Japanese wild raccoon dogs was analyzed. The 13,837bp circular genome contained 13 protein-coding genes, two rRNA genes, and 22 tRNA genes. For the first time, two tRNAs (alanine and tyrosine), that were thought to be absent in scabies mites from other animals, were predicted to have short, non-cloverleaf structures by in silico annotation and detected by RT-PCR, sequencing, and northern analysis. The mitochondrial genome structure of S. scabiei is similar to that of Psoroptes cuniculi and Dermatophagoides farinae. While small and unusual tRNA genes seem to be common among acariform mites, further experimental evidence for their presence is needed. Furthermore, through an analysis of the cox1 gene, we have provided new evidence to confirm the transmission of this mite between different animal hosts.

The relationship between type 1 IFN and vasculopathy in anti-MDA5 antibody-positive dermatomyositis patients.

OBJECTIVE: Based on the antibody profiles of inflammatory myositis patients, we investigated the type 1 IFN (T1-IFN) signature in serum and DM skin to determine the relationship between T1-IFN and vasculopathy in anti-melanoma differentiation-associated 5 gene (MDA5) antibody-positive DM patients. METHODS: We examined 47 patients with new-onset inflammatory myositis. We divided them into three groups: the anti-MDA5 antibody-positive patients (MDA5 group, n = 16), the anti-aminoacyl-tRNA synthetase antibody-positive patients (aminoacyl-tRNA synthetase group, n = 12), and the double-negative patients (n = 19). Serum T1-IFN signatures were revealed by a functional reporter assay, and we evaluated the T1-IFN signatures of skin based on Mx1 expression by immunohistochemistry. RESULTS: The numbers of patients with classical DM, clinically amyopathic DM and interstitial lung disease were 1, 15 and 13 in the MDA5 group, 2, 3 and 11 in the aminoacyl-tRNA synthetase group, and 10, 1 and 4 in the double-negative group, respectively. The signs of vasculopathies (i.e. palmer papules, skin ulcers and mononeuritis multiplex) were identified only in the MDA5 patients. Most of the MDA5 group showed the highest serum T1-IFN signatures among the three groups. In the histological analysis of DM skin, perivascular inflammations were significant in the MDA5 group. The MDA5 group's Mx1 expression was significantly strong, distributed in blood vessels and interstitial fibroblasts, and had spread to deep dermis. CONCLUSION: Anti-MDA5 antibody-positive DM patients showed high T1-IFN signatures in serum and affected skin. The high T1-IFN signatures of the MDA5 antibody-positive DM patients in serum and deep vasculatures suggested that T1-IFN may have important roles in the vasculopathy of these patients.

Are the 2016 EULAR/ACR/PRINTO classification criteria for macrophage activation syndrome applicable to patients with adult-onset Still's disease?

The objectives of this study are to determine whether the 2016 European League Against Rheumatism/American College of Rheumatology/Paediatric Rheumatology International Trials Organization classification criteria for macrophage activation syndrome (MAS) complicating systemic juvenile idiopathic arthritis (SJIA) can be used to identify MAS in patients with adult-onset Still's disease (AOSD). Using laboratory data from 76 AOSD patients with and without MAS, we analyzed the ability of the collective and individual constitutive elements of the 2016 MAS in SJIA criteria and additional laboratory measures to discriminate between AOSD patients with (n = 16) and without (n = 60) MAS. Cutoff values to determine the sensitivity, specificity, and predictive values were calculated from receiver operating characteristic curves, and modified classification criteria for MAS in AOSD were evaluated. The 2016 MAS in SJIA classification criteria had an overall sensitivity of 100%, specificity of 70.0%, positive predictive value of 47.1%, and negative predictive value of 100% to discriminate between AOSD patients with and without MAS based on laboratory data. Among the individual criteria, the sensitivity of triglycerides (46.7%) and the specificity of ferritin (15.0%) for MAS in AOSD were particularly low. The sensitivity and specificity for classifying MAS in AOSD patients were increased to 100 and 93%, respectively, by excluding triglycerides and changing the cutoff values for other criteria in the 2016 MAS in SJIA classification. The 2016 classification criteria for MAS in SJIA had higher sensitivity but lower specificity to identify MAS in AOSD patients compared with SJIA patients.

Successful golimumab therapy in four patients with refractory Takayasu's arteritis.

Recent studies suggested that anti-TNF-α biological therapies are effective in treating Takayasu's arteritis (TA) refractory to conventional immunosuppressive therapy. However, the efficacy of golimumab (GLM) for TA therapy is unknown. We report four women with TA who were successfully treated with GLM. GLM was prescribed as induction therapy for three patients and as maintenance therapy for one patient. GLM showed therapeutic value and might be useful, together with other anti-TNF-α agents, in treating TA.

Beneficial use of serum ferritin and heme oxygenase-1 as biomarkers in adult-onset Still's disease: A multicenter retrospective study.

BACKGROUND: Heme oxygenase (HO)-1 is a heme-degrading enzyme highly expressed in monocyte/macrophage, serum levels of which may be promising biomarker for adult-onset Still's disease (AOSD). We here report data on the use of serum ferritin and HO-1 levels in AOSD. METHODS: Under the Hypercytokinemia Study Group collaboration, we collected sera from a total of 145 AOSD patients. Three independent experts judged whether the patients were definite AOSD depending on the clinical information. These 91 'definite AOSD' patients were further divided into active, remission, and relapse groups. Forty-six cases of systemic vasculitis, sepsis, etc. were included as disease controls. Serum ferritin and HO-1 levels were measured using ELISA. Associations between clinical symptoms, serum ferritin, and HO-1 were explored. Multivariate regression analysis was performed to identify independent variables associated with definite AOSD diagnosis. RESULTS: Serum ferritin and HO-1 levels were significantly higher in active and relapsed AOSD cases compared to disease controls, and were reduced by the treatment. Although a significant correlation was found between serum ferritin and HO-1 levels, a discrepancy was found in some cases such as iron-deficiency anemia. Receiver operating characteristic analysis identified optimal levels of serum ferritin (>819 ng/ml; sensitivity 76.1% and specificity 73.8%), and serum HO-1 (>30.2 ng/ml; sensitivity 84.8% and specificity 83.3%) that differentiated AOSD from controls. Interestingly, 88.9% of patients with AOSD who relapsed exceeded the cut-off value of serum HO-1 > 30.2 ng/ml, but only 50.0% exceeded serum ferritin >819 ng/ml (p = .013), suggesting that serum HO-1 levels may be a convenient indicator of AOSD disease status. Multivariate analysis identified neutrophilia, RF/ANA negativity, sore throat, and elevated serum HO-1 as independent variables associated with AOSD diagnosis. CONCLUSION: We confirmed that serum ferritin and HO-1 serve as highly specific and sensitive biomarkers for AOSD. A future prospective study with large sample size is necessary to determine whether these biomarkers could be included in Yamaguchi's Criteria.

The balance between Foxp3 and Ror-γt expression in peripheral blood is altered by tocilizumab and abatacept in patients with rheumatoid arthritis.

BACKGROUND: The balance between Th17 cells and regulatory T (Treg) cells has been shown to play an important role in the development of rheumatoid arthritis (RA). Recent studies have shown that treatment with abatacept (ABT) or tocilizumab (TCZ) affects Th17 and Treg cell populations. Although not unanimously accepted, several reports have shown that Treg cells are decreased by ABT and increased by TCZ, and that Th17 cells are decreased by TCZ. To further investigate the effects of ABT and TCZ on the skewing of T cell populations, we analyzed the expression of master regulators genes of helper T cell lineages following ABT/TCZ treatment of RA patients. METHODS: Ten patients treated with ABT and 10 patients treated with TCZ were enrolled. Total RNA was extracted from peripheral blood cells at baseline, and after 12 and 24 weeks of therapy. The expression levels of T-bet, GATA3, Foxp3 and Ror-γt were semi-quantified using real-time PCR. The relative expression levels were expressed as the ratios of two genes (T-bet/GATA3, Foxp3/GATA3, Foxp3/T-bet, Foxp3/Ror-γt, Ror-γt/T-bet, Ror-γt/GATA3), and the changes in these ratios with treatment were determined. RESULTS: The Foxp3/Ror-γt ratio was decreased after ABT therapy (0.67 ± 0.16 at 24 weeks, P = 0.0034) but was increased after TCZ therapy (2.00 ± 1.03 at 24 weeks, P = 0.0013). In addition, the Ror-γt/GATA3 ratio was decreased after TCZ therapy (0.78 ± 0.37 at 24 weeks, P = 0.0008). Except for these ratios, no significant skewing in the expression of these factors was detected. No significant relationship between clinical response to the treatment and change in the ratios of these factors was determined. CONCLUSION: Treatment with TCZ or ABT differently affected the balance between Foxp3 and Ror-γt expression in the peripheral blood of patients with RA.

Characteristics of MPO-ANCA-positive granulomatosis with polyangiitis: a retrospective multi-center study in Japan.

We studied the clinico-pathological differences among PR3-ANCA-positive granulomatosis with polyangiitis (PR3-GPA), MPO-ANCA-positive GPA (MPO-GPA) and microscopic polyangiitis (MPA). ANCA-associated vasculitis (AAV) was classified using the European Medicines Agency classification. We retrospectively analyzed 38 patients with GPA and 41 with MPA treated in eight hospitals in Japan. Of the patients with GPA, 17 were positive for MPO-ANCA, and 15 for PR3-ANCA. All patients with MPA were MPO-ANCA positive. The mean ages of those with MPO-GPA were 69.6 years old, 10 years older than those with PR3-GPA. The majority (82 %) of patients with MPO-GPA were woman, a significantly greater proportion than for PR3-GPA. We also found that ear, nose and throat (ENT), nervous system involvement were significantly more common in MPO-GPA, but renal function was less impaired than those with MPA. Both PR3-GPA and MPO-GPA relapsed more frequently than MPA, but overall survival was significantly better (P < 0.01 and P < 0.05, respectively). Univariate analysis identified the following factors as predictors of a poor prognosis: MPA (P < 0.01), pulmonary UIP pattern (P < 0.005) Cr ≥ 1.7 mg/dl (P < 0.01) and absence of ENT involvement (P < 0.05), which were characteristics of MPA. In our cohort, MPO-GPA was most likely to affect older women and was associated with otitis media, nervous system involvement, mild renal impairment and more favorable outcome. It is clinically useful to differentiate MPO-GPA from MPA and PR3-GPA in patients with AAV.

Psychological stress in a Japanese population with systemic lupus erythematosus: finding from KYSS study.

OBJECTIVES: Daily psychological stress has been proposed as a risk factor for systemic lupus erythematosus (SLE) in Western countries. However, there is little information about the relationship between daily psychological stress and the risk of SLE in a Japanese population. We examined the association between SLE and daily psychological stress. METHODS: A case-control study was conducted to examine the relationship between daily psychological stress and SLE in Japanese females. The participants were 160 female SLE patients and 660 female volunteers. Unconditional logistic regression was used to compute OR and 95% confidence interval (CI), with adjustment for several covariates. RESULTS: Smoking (OR = 2.59; 95% CI, 1.74-3.86), walking (OR = 1.75; 95% CI, 1.81-2.56) and daily psychological stress (OR = 1.88; 95% CI, 1.14-3.10) were increased in patients with SLE after adjusting for age, region and all factors. Smokers with daily psychological stress (OR = 4.70; 95% CI = 2.53-8.77) were more prevalent than nonsmokers without daily psychological stress in SLE. The multiplicative interaction measures between smoking status and daily psychological stress did not reach statistical significance. CONCLUSIONS: The present study suggests the possibility that daily psychological stress as well as smoking might be associated with an increased risk of SLE.

Lifestyle and other related factors for the development of mixed connective tissue disease among Japanese females in comparison with systemic lupus erythematosus.

OBJECTIVE: The etiology of mixed connective tissue disease (MCTD) has not been elucidated in detail. Case control studies of MCTD and systemic lupus erythematosus (SLE) were conducted in order to compare factors related to these two diseases. METHODS: We selected 48 MCTD and 54 SLE female patients throughout Japan from 2009 to 2010. Controls were 182 female patients who visited the clinics of general internal medicine during the study periods. RESULTS: Smoking and walking a longer time showed an increased age-adjusted risk for MCTD as well as SLE. On the other hand, frequent intake of bread increased the risk of MCTD and high intake of green tea decreased the risk of MCTD. Even after an additional adjustment of smoking and drinking, frequent intake of bread increased the risk of MCTD, while walking increased the risk of SLE. CONCLUSION: The present study suggests that Westernization of dietary habits (i.e. frequent intake of bread and low intake of green tea) may increase the risk of MCTD, while walking may increase the risk of SLE (probably due to exposure to the sunlight) among Japanese females. Further studies are needed to confirm the result of the present study.