Clinical subsets associated with different anti-aminoacyl transfer RNA synthetase antibodies and their association with coexisting anti-Ro52.

OBJECTIVE: To characterize clinical features of polymyositis/dermatomyositis (PM/DM) patients with different anti-aminoacyl transfer RNA synthetase (ARS) antibodies and their association with anti-Ro52. METHODS: Autoantibodies in sera from 97 Japanese patients (36 PM, 56 DM, and 5 clinically amyopathic DM), who satisfied Bohan and Peter or modified Sontheimer's criteria, were characterized by immunoprecipitation and enzyme-linked immunosorbent assay. Clinical information was from medical records. Features associated with different anti-ARS and anti-Ro52 antibodies were analyzed. RESULTS: The prevalence of anti-ARS was similar to other studies (Jo-1, 22%; EJ, 4%; OJ, 1%; PL-12, 1%), except for a high prevalence of anti-PL-7 (12%), which allowed us to characterize patients carrying this specificity. Serum creatine kinase >3000 IU/l was less common in anti-PL-7-positive patients (57%) than anti-Jo-1-positive patients (18%) (p = 0.0328) and was not found in anti-EJ-positive individuals. Interstitial lung disease was common in anti-ARS-positive patients (97%) (p < 0.0001 vs. 48% in anti-ARS-negative). Anti-Ro52 antibodies were frequently detected with anti-ARS (59%) (57% in anti-Jo-1, 67% in anti-PL-7) (vs. 21% in anti-ARS-negative, p < 0.0002). Anti-Ro52 was associated with overlap syndrome (26%) (vs. 7% in anti-Ro52-negative, p = 0.0119). CONCLUSIONS: Patients with different anti-ARS in combination with anti-Ro52 appear to be associated with distinctive clinical subsets.

Protein profiles of peripheral blood mononuclear cells as a candidate biomarker for Behçet's disease.

OBJECTIVES: To investigate the pathophysiology of Behçet's disease (BD) and find biomarkers for the disease, we analysed protein profiles of peripheral blood mononuclear cells (PBMCs). METHODS: Proteins, extracted from PBMCs, were comprehensively analysed in 16 patients with BD, 16 patients with rheumatoid arthritis (RA), 12 patients with Crohn's disease (CD), and 16 healthy control subjects (HC) by 2-dimensional differential gel electrophoResis (2D-DIGE). Differently expressed proteins were identified by mass spectrometry. RESULTS: 563 protein spots were detected. We completely discriminated between the BD and HC groups, between the BD and RA groups, and between the BD and CD groups by multivariate analysis of intensity of 23, 35, and 1 spots, respectively. The spots contributing to the differences included proteins related to cytoskeleton, transcription/translation, T cell activation, bone turnover, regulating apoptosis, and microbial infection. Intensity of 3 spots (tyrosine-protein phosphatase non-receptor type 4, threonine synthase-like 2, and ß-actin) provided area under the receiver operating characteristic curves (AUROC) of 0.889 for discrimination between the BD group and the non-BD groups. Informatively, intensity of the above 1 spot completely discriminated the CD group from the other groups (AUROC 1.000). This spot, identified as ß-actin, had different pI from the above ß-actin-spot probably due to different post-translational modification. CONCLUSIONS: PBMC protein profiles, especially the profile of the 3 spots, would be candidate biomarkers for BD. The latter ß-actin subtype would be useful for discriminating inflammatory bowel diseases from BD and other diseases. The identified proteins may play important roles in the pathophysiology of BD.

Cutaneous polyarteritis nodosa associated with HLA-B39-positive undifferentiated spondyloarthritis in a Japanese patient.

We present the case of a 43-year-old man diagnosed with HLA-B39-positive spondyloarthritis who developed cutaneous lesions consistent with cutaneous polyarteritis nodosa (CPN). Previous studies indicated an elevated incidence of HLA-B39 in HLA-B27-negative Japanese patients with spondyloarthritis. This case suggested that CPN may also occur in association with forms of HLA-B39-positive spondyloarthritis. The rarity of this association is emphasized. Therapy with corticosteroid and methotrexate improved both the cutaneous lesions and the clinical symptoms of spondyloarthritis.

[Review article: Antineutrophil cytoplasmic antibody in small vessel vasculitis].

The vasculitides are defined by the presence of leukocytes in vessel walls with reactive damage to mural structures. Vasculitis may occur as a primary process or may be secondary to another underlying disease. In general, the affected vessels vary in size, type, and location in association with the specific vasculitic disorder. Classically, vasculitic syndromes have been categorized by the predominant sizes of the blood vessels and types of vessel most commonly affected among patients with the disorder. Currently, antineutrophil cytoplasmic antibody (ANCA) testing plays a critical role in the pathogenesis, diagnosis, and classification of vasculitides. Two types of ANCA assay (indirect immunofluorescence assay and enzyme-linked immunosorbent assay (ELISA)) are in wide use. Two major immunofluorescence patterns are observed, the C-ANCA and P-ANCA patterns. In vasculitis, the two relevant target antigens for ANCA are proteinase 3 (PR3) and myeloperoxidase (MPO). Antibodies with target specificities for PR3 and MPO are called PR3-ANCA and MPO-ANCA, respectively. Vasculitides associated with serum positivity for ANCA that affect small to medium-sized vessels are commonly known as ANCA-associated vasculitis and include Wegener's granulomatosis, microscopic polyangiitis, and Churg-Strauss syndrome. In this article, the pathogenesis of ANCA will be reviewed as well as the pitfalls regarding its clinical application.

Recurrent Bilateral Focal Myositis.

This report describes a rare case of recurrent bilateral focal myositis and its successful treatment via methotrexate. A 38-year-old man presented myalgia of the right gastrocnemius in May 2005. Magnetic resonance imaging showed very high signal intensity in the right gastrocnemius on short-tau inversion recovery images. A muscle biopsy revealed inflammatory CD4+ cell-dominant myogenic change. Focal myositis was diagnosed. The first steroid treatment was effective. Tapering of prednisolone, however, repeatedly induced myositis relapse, which progressed to multiple muscle lesions of both lower limbs. Initiation of methotrexate finally allowed successful tapering of prednisolone, with no relapse in the past 4 years.

Comparative proteomic analysis of neutrophils from patients with microscopic polyangiitis and granulomatosis with polyangiitis.

Both microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA) belong to ANCA-associated vasculitis (AAV), in which neutrophils play a key role in their pathology. In this study, in order to discriminate between MPA and GPA, protein profiles of peripheral blood polymorphonuclear cells (PMNs) of 11 MPA patients and 9 GPA patients and 10 healthy controls (HC) were analyzed by 2D-DIGE. In all the 864 spots detected, intensity of 55 spots was significantly different (p<0.05) among the three groups by ANOVA. 31 out of the 55 spots were identified by mass spectrometry. Orthogonal partial-least-squares-discriminate analysis revealed that the abundance profile of the protein spots discriminated the AAV group from the HC group, and the MPA group from the GPA group completely. 13 protein spots were considered as biomarker candidates to distinguish between MPA and GPA. In those, spots whose intensity was higher in MPA than in GPA included actin with various pI values, while a considerable part of spots whose intensity was higher in GPA were proteins related with the activity of neutrophils. Among the candidate proteins, ROC analysis showed that a combination of neutrophil gelatinase-associated lipocalin and a-kinase anchor protein 7 isoforms beta had a high diagnostic potential. BIOLOGICAL SIGNIFICANCE: In this study, protein profiles of polymorphonuclear cells (PMNs) of microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA) patients and healthy controls (HC) were investigated by 2D-DIGE, and MS analysis. As a result, we found that the protein profiles of PMNs were useful for distinguishing between patients (MPA and GPA) and HC, and between patients with MPA and patients with GPA. Especially, we found that the 13 protein spots that consisted of 10 proteins considerably contributed to the discrimination between MPA and GPA. This is the first to demonstrate that protein profiles of PMNs are different among MPA, GPA and healthy control. The 10 proteins we identified in this study would be new biomarkers for the diagnosis of the diseases, and may be reflect the pathology difference between MPA and GPA.

[A case of primary Sjögren's syndrome complicated by chronic progressive myositis].

The patient was a 64-year-old woman with a nearly 20-year history of sicca symptoms, having been given a diagnosis of primary Sjögren's syndrome. Three years previously, she experienced difficulty in walking up a slope and had leg malaise, which insidiously progressed to an inability to go up and down stairs. This disability brought her to our hospital, where her muscle strength was examined by manual muscle testing, and she was found to have reduced muscle strength in proximal muscles like the thigh muscles and the neck flexor muscles. Blood studies revealed elevated ESR, increased serum IgG, mildly increased myogenic enzymes, and positive results for anti-SS-A and -SS-B antibodies. MRI scans disclosed extensive muscle atrophy as well as fatty degeneration in the thigh. A biopsy of the quadriceps femoris muscle provided a diagnosis of myositis based on the finding of muscle fibers of unequal size, nuclear centralization, and inflammatory cell infiltration into muscle fibers. CD4-positive lymphocytes were the predominant inflammatory cells. We diagnosed the case as myositis in primary Sjögren's syndrome based on the clinical course and laboratory findings. She recovered well with steroid medication. It is noteworthy that myositis associated with primary Sjögren's syndrome presents with mild symptoms and unremarkable laboratory data but may run a chronic progressive course.

Proteomic surveillance of autoantigens in patients with Behcet's disease by a proteomic approach.

To promote an understanding of autoimmunity in BD, we surveyed autoAgs in patients with BD and investigated the prevalence and clinical significance of the identified autoAbs. Specifically, proteins, extracted from peripheral blood mononuclear cells and separated by 2DE, were subjected to WB, using five serum samples from patients with BD. The detected candidate autoAgs were identified by mass spectrometry. As a result, 17 autoantigenic spots were detected by the 2DE-WB, out of which eight spots were identified. They are enolase-1, cofilin-1, vimentin, Rho-GDI beta protein, tubulin-like protein, and actin-like proteins. The autoAbs to one of the identified proteins, cofilin-1, were investigated by WB using a recombinant protein in 30 patients with BD, 35 patients with RA, 32 patients with SLE, and 16 patients with PM/DM. The autoAbs to cofilin-1 were detected by WB in four (13.3%) of the 30 patients with BD, five (14.3%) of the 35 patients with RA, two (6.3%) of the 32 patients with SLE, and eight (24.2%) of the 33 patients with PM/DM. Our data indicate that the generation of autoAbs to cofilin-1 may reflect common immunological disorders in BD, RA, and PM/DM. Our data would help understanding of the immunopathology of BD. In addition, the proteomic approach would be a useful way to investigate autoAgs.