Hiromitsu Asashima

The role of M3 muscarinic acetylcholine receptor reactive T cells in Sjögren's syndrome: A critical review

CD4+ T cells constitute the majority of infiltrating cells in salivary glands and lachrymal glands of patients with Sjögrens syndrome (SS). The pathophysiology of SS involves T cell recognition of antigens through the T cell antigen receptor, which triggers cytokine production and chronic inflammation. The M3 muscarinic acetylcholine receptor (M3R) molecule is expressed in exocrine glands, such as salivary glands and lachrymal glands, and plays an important role in exocrine secretion. Previous studies indicated the presence of M3R reactive T cells in peripheral blood of 40% of patients with SS and autoantibodies against M3R in sera of 9-100% of the same patients. Thus, M3R is considered a candidate receptor for autoantigen recognition by T and B cells. The relationship between B cell epitopes and the function of anti-M3R antibodies has been reported, suggesting the pathogenic role of anti-M3R antibodies in xerostomia commonly seen in SS patients. We generated new experimental mouse model, M3R-induced sialadenitis (MIS), using Rag1(-/-) mice inoculated with splenocytes from M3R(-/-) mice immunized with M3R synthetic peptides. Mice with MIS developed severe SS-like sialadenitis. Cell transfer experiments using M3R(-/-)xIFNγ(-/-) mice and M3R(-/-)xIL-17(-/-) mice showed that IFNγ and IL-17 are key cytokines in the pathogenesis of sialadenitis. These findings indicate the crucial roles of M3R-reactive Th1 and Th17 cells in autoimmune sialadenitis, and suggest that these cells, in addition to anti-M3R antibodies, are potential targets in new treatments for SS.

Efficacy and safety of abatacept for patients with Sjögren's syndrome associated with rheumatoid arthritis: Rheumatoid Arthritis with Orencia Trial toward Sjögren's syndrome Endocrinopathy (ROSE) trial—an open-label, one-year, prospective study—Interim analysis of 32 patients for 24 weeks

Abstract Objective. To assess the efficacy and safety of abatacept for secondary Sjögrens syndrome (SS) associated with rheumatoid arthritis (RA). Methods. The primary endpoint of this 1-year, open-labeled, prospective, observational multicenter study of RA-associated secondary SS was the rate of SDAI remission at 52 weeks after initiation of abatacept therapy. The secondary endpoints included that of Saxsons test and Schirmers test. Adverse events during the study period were also analyzed. Results. Thirty-two patients (all females) were enrolled in this study. Interim analysis at 24 weeks included assessment of efficacy (n = 31) and safety (n = 32). The mean SDAI decreased from 19.8 ± 11.0 (± SD) at baseline to 9.9 ± 9.9 at 24 weeks (P < 0.05). Patients with clinical remission, as assessed by SDAI, increased from 0 patient (0 week) to 8 patients (25.8%) at 24 weeks. Saliva volume (assessed by Saxsons test) increased slightly from 2232 ± 1908 (0 week) to 2424 ± 2004 (24 weeks) mg/2 min (n = 29). In 11 patients with Greenspan grading 1/2 of labial salivary glands biopsy, saliva volume increased from 2945 ± 2090 (0 week) to 3419 ± 2121 (24 weeks) mg/2 min (P < 0.05). Schirmers test for tear volume showed increase from 3.6 ± 4.6 (0 week) to 5.5 ± 7.1 (24 weeks) mm/5 min (n = 25; P < 0.05). Five adverse events occurred in five of 32 patients (15.6%), and three of these events were infections. Conclusion. Abatacept seems to be effective for both RA and RA-related secondary SS.

Primary and secondary surveys on epidemiology of Sjögren's syndrome in Japan

Abstract Objective. To characterize the epidemiology of Sjögrens syndrome (SS), including prevalence, disease type, extra-glandular involvement, satisfaction of diagnostic criteria sets, and treatment used in Japan. Methods. The Research Team for Autoimmune Diseases, the Research Program for Intractable Disease by the Ministry of Health, Labor and Welfare conducted primary and secondary surveys on epidemiology of SS in 2011. The primary survey covered 4,729 out of 14,095 Japan-wide Hospital Departments to investigate the prevalence of SS. The secondary survey encompassed 214 Hospital Departments that agreed to the survey, to characterize disease type, extra-glandular involvement, satisfaction of diagnostic criteria sets, and treatments. Results. The number of patients with SS in Japan estimated by the primary survey was 68,483. The secondary survey involving data collected from 2,195 SS patients from 98 Hospital Departments showed that the mean age of patients was 60.8 ± 15.2 years, male/female ratio was 1/17.4, primary/secondary SS was about 60%/40% and glandular/extra-glandular form in primary SS was about 70%/25%. The satisfaction rate was 53.8% for the 1999 revised Japanese Ministry of Health criteria for the diagnosis of SS, 47.7% for the 2002 American–European Consensus Group classification criteria for SS and 49.6% for 2012 American College of Rheumatology classification criteria for SS. Corticosteroids were used by 752 of 2,195 patients (34%), immunosuppressants by 358 patients (16%), biologics by 68 patients (3%) and secretagogues by 695 patients (32%). Conclusion. The surveys provided valuable information on the epidemiology of SS including prevalence, disease type, extra-glandular involvement, satisfaction of diagnostic criteria sets and treatments used today in Japan.

A Crucial Role of RORγt in the Development of Spontaneous Sialadenitis-like Sjögren’s Syndrome

The nuclear receptor retinoic acid–related orphan receptor (ROR)γt is required for the generation of Th17 cells, which are involved in various autoimmune diseases, including Sjögren’s syndrome (SS). However, the pathological role of RORγt in SS remains to be elucidated. The present study was designed to clarify the role of RORγt in the pathogenesis of sialadenitis-like SS. Histological analysis of RORγt transgenic (Tg) mice was determined, and then Tg mice developed severe spontaneous sialadenitis-like SS. The analysis of infiltrating cells showed that most infiltrating cells were CD4+ T cells. RORγt-overexpressing CD4+ T cells induced sialadenitis as a result of transferred CD4+ T cells from Tg mice into Rag2−/− mice. The examination of IL-17–deficient Tg mice indicated that IL-17 was not essential for the development of sialadenitis. The number of CD4+CD25+Foxp3+ regulatory T (Treg) cells was significantly decreased in Tg mice, and CD25 expression and IL-2 stimulated STAT5 activation were inhibited in Treg cells. The inhibitory function of Treg cells of Tg mice was equal to that of wild-type mice in vitro. The abundant Treg cells of Tg mice could suppress the development of sialadenitis, but the reduced Treg cells of Tg mice could not inhibit the induction of sialadenitis in Rag2−/− mice transferred with effector cells from Tg mice. These results suggest that both RORγt-overexpressed CD4+ T cells and reduced Treg cells might contribute to the development of SS-like sialadenitis.

Clinicopathological features of IgG4-related disease complicated with orbital involvement

Abstract Objective. IgG4-related disease (IgG4-RD) is characterized by IgG4-positive plasmacytic infiltration and fibrosis in various organs. Orbital involvement in IgG4-RD includes lacrimal glands, extra-ocular muscles, trigeminal nerve and other parts of the orbit. Immunohistochemical staining is used to diagnose IgG4-RD in patients with orbital inflammation. The purpose of this retrospective study was to clarify the clinicopathological features of IgG4-RD complicated with orbital involvement. Methods. We examined the clinical features, pathological findings and response to treatment in nine patients with IgG4-RD who underwent orbital tissue biopsy between April 2010 and August 2012 at the University of Tsukuba Hospital. Results. Among the nine patients, eight had dacryoadenitis, one had infraorbital nerve swelling, and another one had IgG4-related orbital inflammation. Involvement of other organs was identified in all patients, including involvement of the salivary glands, lymph nodes, lung, kidney and para-aorta. In all patients, biopsy samples from orbital tissues showed lymphoplasmacytic infiltration and fibrosis, and IgG4-positive/IgG-positive plasmacyte ratio of > 40%. All patients were treated with prednisolone (0.6 mg/kg/day) and responded well in early phase, although relapse was noted in two patients following tapering of prednisolone, evident by swelling of lacrimal glands. Conclusion. Patients with IgG4-RD complicated with orbital involvement often present with involvement of other organs. The histopathological findings of orbital tissue match the characteristic features of IgG4-RD. Corticosteroid is effective for orbital and systemic involvement in IgG4-RD.

DNA microarray analysis of labial salivary glands in IgG4-related disease: Comparison with Sjögren's syndrome

To compare gene expression in labial salivary glands (LSGs) from patients with IgG4‐related disease with that in LSGs from patients with Sjögrens syndrome (SS).

Effectiveness of abatacept for patients with Sjögren’s syndrome associated with rheumatoid arthritis. An open label, multicenter, one-year, prospective study: ROSE (Rheumatoid Arthritis with Orencia Trial toward Sjögren’s syndrome Endocrinopathy) trial

Abstract Objective: To clarify the efficacy and safety of abatacept for secondary Sjögren’s syndrome (SS) associated with rheumatoid arthritis (RA). Methods: The primary endpoint of this open-labeled, prospective, observational multicenter study for secondary SS with RA was the remission rate of Simplified Disease Activity Index (SDAI) at 52 weeks after initiation of abatacept. The secondary endpoints included Saxon’s test and Schirmer’s test. Adverse events and adherence rate during the study period were also analyzed. Results: Thirty-six patients (all females) were enrolled in this study. The mean SDAI decreased significantly from 20.6 ± 11.2 (±SD) at baseline to 10.0 ± 10.5 at 52 weeks (p < 0.05). Patients with SDAI remission increased from 0 (0 week) to 12 patients (33.3%) at 52 weeks. Saliva volume assessed by Saxon’s test increased significantly from 2136 ± 1809 (0 week) to 2397 ± 1878 (24 weeks) mg/2 min (n = 34, p < 0.05). Saliva volume increased significantly from 2945 ± 2090 (0 week) to 3419 ± 2121 (24 weeks) mg/2 min in 11 patients with Greenspan grade 1 or 2 of labial salivary gland biopsy (p < 0.05), but no change was noted in 18 patients with Greenspan grade 3 or 4. Tear volume by Schirmer’s test increased significantly from 4.2 ± 4.8 (0 week) to 6.4 ± 7.8 (24 weeks) mm/5 min (n = 30, p < 0.05). The adherence rate to abatacept was 80.6% (29/36) over the 52-week period. Twelve adverse events occurred in 10 of the 36 patients, and 7 of these events were infections. Conclusion: Abatacept seems to be effective for both RA and SS related manifestations.

Clinical features of patients with IgG4-related disease complicated with perivascular lesions

Abstract Objective. To define the clinical features of IgG4-related disease (IgG4-RD) complicated with perivascular lesions. Methods. The clinical features of seven patients with IgG4-RD and perivascular lesions diagnosed at the University of Tsukuba Hospital between October 2008 and October 2013, were analyzed, including clinical background, results of imaging studies, satisfaction of the 2011 comprehensive diagnostic criteria (CDC) for IgG4-RD, laboratory data, distribution of perivascular lesions, involvement of other organs, and response to steroid therapy. Results. We studied six men and one woman with a mean age of 66.9 ± 6.7 years (± SD). Six of seven patients were diagnosed as definite IgG4-RD, while the seventh was considered possible IgG4-RD, based on the CDC for IgG4-RD. Serum IgG4 levels at diagnosis were higher than 135 mg/dl in all seven patients (mean, 933 ± 527). Serum C-reactive protein (CRP) levels were elevated in two only (mean, 1.42 ± 3.56 mg/dl). The perivascular lesions were located in the pulmonary artery (n = 1), thoracic aorta (n = 2), abdominal aorta (n = 6), coronary (n = 1), celiac (n = 1), superior mesenteric (n = 1), renal (n = 2), inferior mesenteric (n = 5), and iliac (n = 3) arteries. In addition to perivascular lesions, six patients showed involvement of other organs. All seven patients were treated with prednisolone (0.6 mg/kg/day), which rapidly improved the perivascular and other organ lesions in six patients (the other one patient have not yet been evaluated due to the short follow-up). Conclusion. Perivascular lesions show wide distribution in patients with IgG4-RD. Serum CRP levels are not necessarily elevated in these patients. Steroid therapy is effective in IgG4-RD and results in resolution of lesions.

Comparison of performance of the 2016 ACR-EULAR classification criteria for primary Sjögren's syndrome with other sets of criteria in Japanese patients

Objectives To compare the performance of the new 2016 American College of Rheumatology (ACR)-European League Against Rheumatism (EULAR) classification criteria for primary Sjögrens syndrome (SS) with 1999 revised Japanese Ministry of Health criteria for diagnosis of SS (JPN), 2002 American-European Consensus Group classification criteria for SS (AECG) and 2012 ACR classification criteria for SS (ACR) in Japanese patients. Methods The study subjects were 499 patients with primary SS (pSS) or suspected pSS who were followed up in June 2012 at 10 hospitals in Japan. All patients had been assessed for all four criteria of JPN (pathology, oral, ocular, anti-SS-A/SS-B antibodies). The clinical diagnosis by the physician in charge was set as the ‘gold standard’. Results pSS was diagnosed in 302 patients and ruled out in 197 patients by the physician in charge. The sensitivity of the ACR-EULAR criteria in the diagnosis of pSS (95.4%) was higher than those of the JPN, AECG and ACR (82.1%, 89.4% and 79.1%, respectively), while the specificity of the ACR-EULAR (72.1%) was lower than those of the three sets (90.9%, 84.3% and 84.8%, respectively). The differences of sensitivities and specificities between the ACR-EULAR and other three sets of criteria were statistically significant (p<0.001). Eight out of 302 patients with pSS and 11 cases out of 197 non-pSS cases satisfied only the ACR-EULAR criteria, compared with none of the other three sets. Conclusions The ACR-EULAR criteria had significantly higher sensitivity and lower specificity in diagnosis of pSS, compared with the currently available three sets of criteria.

The crucial roles of IFN-γ in the development of M3 muscarinic acetylcholine receptor induced Sjögren’s syndrome-like sialadenitis

Sjögren’s syndrome (SS) is a chronic autoimmune disease characterized by infiltration of lymphocytes into lacrimal and salivary glands, and clinically by dry eyes and dry mouth. Auto-antigens recognized by T cells infiltrating the salivary glands of patients with SS have been analyzed, and several candidate auto-antigens such as M3 muscarinic acetylcholine receptor (M3R) have been identified. The presence and specificity of anti-M3R antibodies in patients with SS have been examined [1–3]. We also reported the presence of IFN-c-producing M3R-reactive CD4 T cells in 40 % of SS patients with SS [4]. Several studies also detected high levels of IFN-c in the salivary glands of SS patients, and then enhanced activity of T cells, B cells, and macrophages, resulting in the destruction and dysfunction of tissue glands [5, 6]. In contrast, IL-17-producing T cells were also found in salivary glands from patients with SS [7]. Our previous study showed that M3R-reactive T cells were involved in the pathogenesis of sialadenitis using M3R-induced sialadenitis (MIS) mice, which are thought to be model mice for SS. In MIS mice, CD3 T cells were essential for the generation of sialadenitis. Moreover, both IFN-c and IL-17 were produced by M3R-reactive T cells and were detected in salivary glands, whereas neither IFNc nor IL-17 was detected in the sera [8]. However, we have no evidence that the cytokines INF-c and/or IL-17 are important in the development of sialadenitis. In the present study, to address the question of whether IFN-c is important in the development of sialadenitis, we generated M3R9IFN-c mice, immunized with M3R peptides, and transferred their splenic cells to Rag-1 mice. Histological findings showed that sialadenitis was more severe in M3R9IFN-c ? Rag1 than that in M3R ? Rag1 mice, but milder than that in M3R ? Rag1 mice (Fig. 1a). Quantitative analysis using histological scores indicated that mononuclear cell infiltration was significantly increased in M3R9IFNc ? Rag1 mice compared with that in M3R ? Rag1 mice (P \ 0.05), but significantly decreased compared with that in M3R ? Rag1 mice (P \ 0.05) (Fig. 1b). These observations support the notion that IFN-c might play a crucial role in the generation of SS-like sialadenitis. The absence of IFN-cand presence of IL-17-producing cells in the salivary glands of M3R9IFN-c ? Rag1 mice were verified by immunohistochemical staining (Fig. 1c). IL-17-producing cells in inflammatory lesions were identified in both M3R9IFN-c ? Rag1 and M3R ? Rag1 mice. IFN-c and IL-17 were not detected in sera from M3R9IFN-c ? Rag1 mice, nor in M3R ? Rag1 mice (data not shown). In M3R ? Rag1 mice, the expression of IL-17 was also observed in salivary glands, as was IFN-c expression. As we have no direct evidence in support of a pathogenic role of IL-17 in MIS, further studies using M3R9IL-17 mice will be necessary to clarify the function of IL-17-producing M3R-reactive T cells. M. Iizuka H. Tsuboi N. Matsuo Y. Kondo H. Asashima I. Matsumoto T. Sumida (&) Department of Internal Medicine, Faculty of Medicine, University of Tsukuba, 1-1-1 Tenodai, Tsukuba, Ibaraki 305-8575, Japan e-mail: tsumida@md.tsukuba.ac.jp