Yuji Hosono

Interstitial Lung Disease in Myositis: Clinical Subsets, Biomarkers, and Treatment

Interstitial lung disease (ILD) is the most frequent organ involvement (found in nearly half) of myositis patients, but it reveals various clinical courses and therapeutic responsiveness according to clinical and serological subsets. Autoantibodies, as well as imaging and histopathological studies, are useful for the classification of ILD in myositis and provide useful information for predicting prognosis and determining treatment. Antisynthetase antibodies are correlated with chronic and recurrent ILD, whereas anti-CADM-140 (MDA5/IFIH1) antibodies are a marker of acute progressive ILD in clinically amyopathic dermatomyositis. Serum KL-6, SP-D, and ferritin are useful biomarkers for monitoring the activity and severity of ILD. Regarding treatment, glucocorticoids are the first-line drug, but additional immunomodulating drugs are also used in refractory patients. Cyclophosphamide and calcineurin inhibitors (cyclosporine and tacrolimus) appear to be the key drugs in the treatment of refractory myositis–ILD. Rituximab may become another candidate if these drugs are not effective.

Etanercept-induced anti-Jo-1-antibody-positive polymyositis in a patient with rheumatoid arthritis: a case report and review of the literature

Antitumor necrosis factor (TNF) therapy has been associated with adverse immunologic events including systemic lupus erythematosus. However, the development of polymyositis (PM)/dermatomyositis (DM) associated with anti-TNF therapy is extremely rare. We experienced a case of a 48-year-old female with rheumatoid arthritis (RA) who had anti-Jo-1 antibodies and interstitial lung disease but no previous history of PM/DM and who developed PM soon after the initiation of etanercept (ETN) therapy for RA. The patient recovered upon withdrawal from ETN and corticosteroid (CS) therapies. Only four reports of PM/DM associated with anti-TNF therapy for RA could be found in the literature. The patients described in three of the four reports were positive for anti-Jo-1 antibodies before the initiation of anti-TNF therapy, and in all the cases, recovery occurred after the cessation of anti-TNF-agent administration and CS therapy. These results suggest a relationship between the onset of PM/DM with anti-Jo-1 antibody and anti-TNF therapy for RA.

Detection of antisynthetase syndrome in patients with idiopathic interstitial pneumonias

OBJECTIVES Antisynthetase syndrome (ASS) is characterized by autoantibodies to aminoacyl-tRNA synthetases (anti-synthetase) and it is frequently associated with interstitial lung disease. The purpose of this study was to elucidate the prevalence and characteristics of the anti-synthetase positive subpopulation among idiopathic interstitial pneumonias (IIPs) and to clarify the importance of screening for these antibodies. METHODS A retrospective study was performed in 198 consecutive cases with IIPs. Screening for six anti-synthetase antibodies was performed in all cases. Clinical profiles of all cases were compared with reference to the presence of anti-synthetase. High-resolution computed tomography (HRCT) findings of anti-synthetase positive cases were also analyzed. RESULTS 13 cases (6.6%) were positive for anti-synthetase. Anti-EJ was most prevalent, followed by anti-PL-12. Onset ages of anti-synthetase positive cases were younger than those of anti-synthetase negative cases. Extrapulmonary features of ASS were absent in 6 anti-synthetase positive cases (46.2%). Histologically, among 5 UIP with lymphoid follicles and 11 NSIP cases, the prevalence of anti-synthetase positive cases was 8/16 (50%). On HRCT, ground glass opacity and traction bronchiectasis were the major findings in anti-synthetase positive cases, while honeycombing was absent. CONCLUSIONS Anti-synthetase positive cases were not rare among IIPs. Anti-synthetase should be screened for in IIPs, especially in pathological NSIP or UIP with lymphoid follicles. These patients should be screened for anti-synthetase even if no suggestive extrapulmonary manifestation exists.

HRCT features of interstitial lung disease in dermatomyositis with anti-CADM-140 antibody

BACKGROUND Anti-CADM-140 antibody (anti-CADM-140), also referred to as anti-melanoma differentiation-associated gene 5 (MDA5) antibody, is a myositis-specific antibody identified in the sera of patients with clinically amyopathic dermatomyositis (C-ADM) and is associated with a worse prognosis in dermatomyositis-associated interstitial lung disease (DM-ILD). We sought to determine high-resolution computed tomography (HRCT) features of DM-ILD with anti-CADM-140. METHODS Twenty-five patients newly diagnosed with DM-ILD at Kyoto University Hospital between 2005 and 2009 were retrospectively reviewed. Serum anti-CADM-140 was measured in all patients at their first visit. Chest HRCT images taken prior to treatment were classified based on the dominant findings and their distribution, and compared between patients with and without the antibody. RESULTS Of 25 DM-ILD patients, 12 were positive and 13 were negative for anti-CADM-140. HRCT patterns differed significantly between anti-CADM-140-positive and negative patients (P = 0.002). Lower consolidation or ground-glass attenuation (GGA) pattern (50.0%) and random GGA pattern (33.3%) were the predominant patterns in anti-CADM-140-positive cases, while lower reticulation pattern (69.2%) was frequently seen in anti-CADM-140-negative cases. Anti-CADM-140-positive cases were also significantly characterized by the absence of intralobular reticular opacities (0% in anti-CADM-140 (+) vs. 84.6% in anti-CADM-140 (-), P < 0.0001). CONCLUSIONS Anti-CADM-140-positive DM-ILD was characterized by lower consolidation or GGA pattern, random GGA pattern, and the absence of intralobular reticular opacities.

The Multicenter Study of a New Assay for Simultaneous Detection of Multiple Anti-Aminoacyl-tRNA Synthetases in Myositis and Interstitial Pneumonia

Objective Autoantibodies to aminoacyl-tRNA synthetases (ARSs) are useful in the diagnosis of idiopathic inflammatory myopathy (IIM) with interstitial pneumonia (IP). We developed an enzyme-linked immunosorbent assay (ELISA) system using a mixture of recombinant ARS antigens and tested its utility in a multicenter study. Methods: We prepared six recombinant ARSs: GST-Jo-1, His-PL-12, His-EJ and GST-KS expressed in Escherichia coli, and His-PL-7 and His-OJ expressed in Hi-5 cells. After confirming their antigenic activity, with the exception of His-OJ, we developed our ELISA system in which the five recombinant ARSs (without His-OJ) were mixed. Efficiency was confirmed using the sera from 526 Japanese patients with connective tissue disease (CTD) (IIM n = 250, systemic lupus erythematosus n = 91, systemic sclerosis n = 70, rheumatoid arthritis n = 75, Sjögren’s syndrome n = 27 and other diseases n = 13), 168 with idiopathic interstitial pneumonia (IIP) and 30 healthy controls collected from eight institutes. IIPs were classified into two groups; idiopathic pulmonary fibrosis (IPF) (n = 38) and non-IPF (n = 130). Results were compared with those of RNA immunoprecipitation. Results: Sensitivity and specificity of the ELISA were 97.1% and 99.8%, respectively when compared with the RNA immunoprecipitation assay. Anti-ARS antibodies were detected in 30.8% of IIM, 2.5% of non-myositis CTD, and 10.7% of IIP (5.3% of IPF and 12.3% of non-IPF). Anti-ARS-positive non-IPF patients were younger and more frequently treated with glucocorticoids and/or immunosuppressants than anti-ARS-negative patients. Conclusion: A newly established ELISA detected anti-ARS antibodies as efficiently as RNA immunoprecipitation. This system will enable easier and wider use in the detection of anti-ARS antibodies in patients with IIM and IIP.

Serum BAFF and APRIL levels in patients with IgG4-related disease and their clinical significance.

IntroductionB cell-activating factor of the tumor necrosis factor family (BAFF) and a proliferation-inducing ligand (APRIL) play a crucial role in B cell development, survival, and antibody production. Here we analyzed the serum levels of BAFF and APRIL and their respective clinical associations in patients with an immunoglobulin (Ig) G4-related disease (IgG4-RD).MethodsWe measured serum levels of BAFF and APRIL in patients with IgG4-RD, primary Sjögrens syndrome (pSS), and healthy individuals. Serum BAFF and APRIL levels in IgG4-RD were assessed for correlations with serological parameters, including Ig, particularly IgG4, and the number of affected organs. Serum BAFF and APRIL levels in IgG4-RD were monitored during glucocorticoid (GC) therapy.ResultsSerum BAFF and APRIL levels in patients with IgG4-RD were significantly higher (P < 0.01) than in healthy individuals. The BAFF levels of patients with IgG4-RD were comparable to those of patients with pSS. Although clinical parameters, such as serum IgG4 and the number of affected organs, were not correlated with the levels of BAFF, serum APRIL levels were inversely correlated with serum IgG4 levels (r = -0.626, P < 0.05). While serum BAFF levels decreased following GC therapy, serum APRIL levels increased during follow-up.ConclusionThese results indicate that BAFF and APRIL might be useful markers for predicting disease activity in IgG4-RD. Further studies are needed to elucidate the role of BAFF and APRIL in the pathogenesis of IgG4-RD.

Clinical significance and new detection system of autoantibodies in myositis with interstitial lung disease

Anti-aminoacyl-tRNA synthetase (ARS) and anti-melanoma differentiation-associated gene 5 (MDA5) antibodies are closely associated with interstitial lung disease in polymyositis and dermatomyositis. Anti-ARS-positive patients develop common clinical characteristics termed anti-synthetase syndrome and share a common clinical course, in which they respond well to initial treatment with glucocorticoids but in which disease tends to recur when glucocorticoids are tapered. Anti-MDA5 antibody is associated with rapidly progressive interstitial lung disease and poor prognosis, particularly in Asia. Therefore, intensive immunosuppressive therapy is required for anti-MDA5-positive patients from the early phase of the disease. New enzyme-linked immunosorbent assays to detect anti-ARS and anti-MDA5 antibodies have recently been established and are suggested to be efficient and useful. These assays are expected to be widely applied in daily practice.

Anti-TIF1-γ antibody and cancer-associated myositis A clinicohistopathologic study

Objective:We aimed to analyze the clinical and histopathologic features of cancer-associated myositis (CAM) in relation to anti–transcriptional intermediary factor 1 &ggr; antibody (anti-TIF1-&ggr;-Ab), a marker of cancer association. Methods:We retrospectively studied 349 patients with idiopathic inflammatory myopathies (IIMs), including 284 patients with pretreatment biopsy samples available. For the classification of IIMs, the European Neuromuscular Center criteria were applied. Patients with CAM with (anti-TIF1-&ggr;-Ab[+] CAM) and without anti-TIF1-&ggr;-Ab (anti-TIF1-&ggr;-Ab[−] CAM) were compared with patients with IIM without cancers within and beyond 3 years of myositis diagnosis. Results:Cancer was detected in 75 patients, of whom 36 (48%) were positive for anti-TIF1-&ggr;-Ab. In anti-TIF1-&ggr;-Ab(+) patients with CAM, cancers were detected within 1 year of myositis diagnosis in 35 (97%) and before 1 year of myositis diagnosis in 1. All the anti-TIF1-&ggr;-Ab(+) patients with CAM satisfied the dermatomyositis (DM) criteria, including 2 possible DM sine dermatitis cases, and were characterized histologically by the presence of perifascicular atrophy, vacuolated fibers (VFs), and dense C5b-9 deposits on capillaries (dC5b-9). In contrast, 39 anti-TIF1-&ggr;-Ab(−) patients with CAM were classified into various subgroups, and characterized by a higher frequency of necrotizing autoimmune myopathy (NAM). Notably, all 7 patients with CAM classified into the NAM subgroup were anti-TIF1-&ggr;-Ab(−) and exhibited no dC5b-9 or VFs. Conclusions:CAM includes clinicohistopathologically heterogeneous disease entities. Among CAM entities, anti-TIF1-&ggr;-Ab(+) CAM has characteristically shown a close temporal association with cancer detection and the histopathologic findings of dC5b-9 and VFs, and CAM with NAM is a subset of anti-TIF1-&ggr;-Ab(−) CAM.

Anti-PM/Scl antibodies are found in Japanese patients with various systemic autoimmune conditions besides myositis and scleroderma

IntroductionAnti-PM/Scl antibodies are associated with polymyositis (PM)/systemic scleroderma (SSc) overlap syndromes and are also found in other systemic autoimmune diseases. Although anti-PM/Scl reactivity is found in 3-11% of PM or SSc patients and in approximately 25% of PM/SSc overlap patients, previous large studies of Japanese patients with scleroderma reported that anti-PM/Scl are not found in Japanese patients at all. The PM/Scl autoantigen complex comprises 11–16 different polypeptides; ELISA with PM1-α peptide, which is a major epitope of the PM/Scl complex, has frequently been used for the detection of these antibodies in recent studies. However, no ELISA kit is commercially available in Japan.MethodsIn this study, we developed an immunoassay for measuring antibodies against recombinant PM/Scl-100 and PM/Scl-75 polypeptides, which are the two major targets of the complex, and we investigated their presence in 600 Japanese patients with various systemic autoimmune conditions. Immunoprecipitation analysis using the recombinants in addition to traditional radiolabeled cell extracts were also applied to ELISA-positive sera.ResultsIn ELISA, 11 patients were positive for anti-PM/Scl-100 antibodies and 7 of these 11 patients were also positive for anti-PM/Scl-75 antibodies. Immunoprecipitation analysis using the recombinants in addition to traditional radiolabeled cell extracts confirmed that 9 out of these 11 patients immunoprecipitated the typical sets of PM/Scl proteins. In total, 4/16 (25%) undifferentiated connective tissue disease (UCTD) patients, 3/126 (2.4%) dermatomyositis patients, 1/223 (0.4%) SSc patients, 1/88 (1.1%) Sjögren’s syndrome patients, 0/123 patients with systemic lupus erythematosus, 0/17 patients with overlap syndrome and 0/7 patients with PM were judged to be positive for anti-PM/Scl antibodies.ConclusionsThis is the first report of Japanese autoimmune patients with anti-PM/Scl antibodies. In Japanese patients, anti-PM/Scl antibodies are only very rarely found, and they are not always specific for dermatomyositis (DM) or SSc; they are also present in various autoimmune conditions with the highest prevalence being in UCTD. All anti-PM/Scl-positive DM cases are complicated with interstitial lung disease and/or cancer, while no life-threatening involvement was found in other anti-PM/Scl-positive cases. Further studies on larger cohorts are necessary to define the clinical significance of anti-PM/Scl antibodies in autoimmune diseases.

Brief Report: Autoantibodies to DNA Mismatch Repair Enzymes in Polymyositis/Dermatomyositis and Other Autoimmune Diseases: A Possible Marker of Favorable Prognosis

Myositis‐specific autoantibodies (MSAs) are useful tools for identifying clinical subsets of patients with idiopathic inflammatory myopathies (IIMs). There have been few reports on antibodies to some DNA mismatch repair enzymes (MMREs) in patients with IIMs. This study was undertaken to determine the frequencies and clinical associations of antibodies to 7 types of MMREs (MLH1, MLH3, MSH2, MSH3, MSH6, PMS1, and PMS2) in patients with IIMs and other systemic autoimmune diseases.