GWAS for systemic sclerosis identifies six novel susceptibility loci including one in the Fcγ receptor region.

Here we report the largest Asian genome-wide association study (GWAS) for systemic sclerosis performed to date, based on data from Japanese subjects and comprising of 1428 cases and 112,599 controls. The lead SNP is in the FCGR/FCRL region, which shows a penetrating association in the Asian population, while a complete linkage disequilibrium SNP, rs10917688, is found in a cis-regulatory element for IRF8. IRF8 is also a significant locus in European GWAS for systemic sclerosis, but rs10917688 only shows an association in the presence of the risk allele of IRF8 in the Japanese population. Further analysis shows that rs10917688 is marked with H3K4me1 in primary B cells. A meta-analysis with a European GWAS detects 30 additional significant loci. Polygenic risk scores constructed with the effect sizes of the meta-analysis suggest the potential portability of genetic associations beyond populations. Prioritizing the top 5% of SNPs of IRF8 binding sites in B cells improves the fitting of the polygenic risk scores, underscoring the roles of B cells and IRF8 in the development of systemic sclerosis. The results also suggest that systemic sclerosis shares a common genetic architecture across populations.

Assessment of oral methotrexate intolerance in Japanese adult patients with rheumatoid arthritis.

AIM: The objective of this study was to assess the gastrointestinal side (GI) effects of oral methotrexate (MTX) in Japanese adult patients with rheumatoid arthritis (RA). METHODS: In this single-center retrospective study, 112 Japanese adult patients (over 18 years old) with RA were examined by Methotrexate Intolerance and Severity assessment in Adults (MISA) questionnaire. RESULTS: Forty-five (40.2%) of patients were MTX intolerant (MISA score ≥1). Twelve patients (11.2%) were moderate-to-severe MTX intolerant (MISA cross-product score ≥4). The most common GI side effects of MTX were gastric discomfort (26.8%), followed by loss of appetite or dysgeusia (14.3%), fatigue and lethargy (12.5%), and nausea (10.7%). CONCLUSIONS: Japanese adult patients with RA showed a high prevalence of MTX intolerance even in low-dose oral MTX. The MISA questionnaire was practical for finding patients with MTX intolerance.

IgG4-related disease administered dupilumab: case series and review of the literature.

Dupilumab (DUP) is a monoclonal antibody that acts on the interleukin (IL)-4 receptor alpha, which inhibits IL-4 and IL-13 signalling and is approved for type 2 inflammatory diseases such as asthma, chronic rhinosinusitis with nasal polyposis and atopic dermatitis; however, the efficacy of DUP to IgG4-related disease (IgG4-RD) is under discussion due to the controversial outcomes based on the several case reports. Here, we reviewed the efficacy of DUP in four consecutive patients with IgG4-RD in our institute and the previous literature.All patients administered DUP fulfilled the 2019 ACR/EULAR classification criteria for IgG4-RD complicated with severe asthma and chronic rhinosinusitis with nasal polyposis. Two cases were administered DUP without systemic glucocorticoids (GCs), and in 6 months, the volume of swollen submandibular glands (SMGs) was reduced by approximately 70%. Two cases receiving GCs successfully reduced their daily dose of GCs (10 and 50% reduction, respectively) with dupilumab in 6 months. In all four cases, serum IgG4 concentration and IgG4-RD responder index decreased in 6 months.DUP reduced the volume of the swollen SMGs, serum IgG4 levels, responder index and the daily dose of GCs in patients with IgG4-RD with severe asthma or eosinophilic rhinosinusitis in 6 months.The efficacy of DUP to IgG4-RD is under discussion due to the limited case reports with controversial outcomes. Here, we demonstrated that two patients with IgG4-RD treated by DUP without systemic GCs, showed volume reduction of swollen SMGs and two cases showed GC-sparing effects by DUP. DUP can ameliorate the disease activity and be a steroid-sparing agent in patients with IgG4-RD.

A Tumefactive Fibroinflammatory Lesion of the Head and Neck Mimicking Immunoglobulin G4-related Disease.

A 67-year-old woman with a 5-year history of recurrent swollen eyelids and epistaxis, diagnosed as immunoglobulin G4-related diseases (IgG4-RD) based on hyper-IgG4-emia and IgG4-positive cell infiltration to the lesion, was referred to our department due to recurrent symptoms despite corticosteroid therapies. Computed tomography revealed an osteoclastic sinus mass with prominent neutrophil infiltration and necrosis that was incompatible with IgG4-RD histopathologically. Finally, she was diagnosed with a tumefactive fibroinflammatory lesion (TFIL) of the head and neck and treated with high-dose corticosteroids. Physicians should remember that TFIL can mimic IgG4-RD in the head and neck region with prominent neutrophil infiltration and necrosis.

Abnormal [18F]fluorodeoxyglucose accumulation to tori tubarius in IgG4-related disease.

OBJECTIVES: Tubarial glands (TGs) are recently refocused gland tissues localized near the tori tubarius in the nasopharynx and their clinical relevance is not clear yet. IgG4-related disease (IgG4-RD) is a progressive fibrosing condition and salivary glands are well-affected lesions. The aim of the present study is to examine [18F]fluorodeoxyglucose ([18F]FDG) accumulation to the tori tubarius in IgG4-related disease (IgG4-RD). METHODS: 48 patients with IgG4-RD who underwent positron emission tomography (PET) scanning with [18F]FDG were included and semi-quantitative analysis of [18F]FDG accumulation to tori tubarius was performed along with the clinical features and histopathological analysis. RESULTS: Of the 48 patients, abnormal [18F]FDG accumulation (metabolic tumour volume ≥ 1) to tori tubarius was observed in 15 (31.3%), all of whom had lesions in other head and neck glands. IgG4-RD patients with abnormal [18F]FDG accumulation to tori tubarius showed swollen nasopharyngeal walls around tori tubarius and forceps biopsy of the lesion revealed acinar cells and IgG4-positive plasma cells histologically. Abnormal [18F]FDG accumulation (maximum standard uptake value, metabolic tumour volume and total lesion glycolysis) to tori tubarius correlated with higher IgG4 and lower IgA serum concentrations. CONCLUSIONS: Abnormal [18F]FDG accumulation to tori tubarius can be observed in patients with IgG4-RD and the abnormal [18F]FDG accumulation to tori tubarius can be a clue of TG involvement in IgG4-RD.

The proton pump inhibitor, lansoprazole, prevents the development of non-traumatic osteonecrosis of the femoral head: an experimental and prospective clinical trial.

BACKGROUND: An effective prevention strategy for osteonecrosis of the femoral head (ONFH) has yet to be established. We previously reported that the innate immune system via the toll-like receptor (TLR) response induced by corticosteroids leads to the development of ONFH and that repression of IRF7 activity by an inhibitor could interfere with the development of ONFH while maintaining the therapeutic effect of the corticosteroids. OBJECTIVE: In the present study, we hypothesize that lansoprazole has the potential to suppress IRF7 activity and prevent corticosteroid-induced ONFH in rats. Furthermore, we conducted a preliminary clinical trial to prevent corticosteroid-induced ONFH in autoimmune disease patients. METHODS: Male Wistar rats were randomly divided into four groups. On Day 1, each rat was injected with TLR4 ligand (LPS) or TLR7 ligand (imiquimod), followed by methylprednisolone with or without lansoprazole on Day 2. They were killed at 1 or 14 days after the last injection.We prospectively recruited 30 patients requiring primary high-dose corticosteroid treatment for immune diseases. All patients were administered lansoprazole, starting the night before corticosteroid treatment began. MRI was performed before corticosteroid treatment, and at 4, 12 and 24 weeks afterward. RESULTS: In rats, co-treatment of lansoprazole with corticosteroids significantly repressed both IRF7 activity and the development of ONFH. Moreover, in the human patients, the incidence of ONFH was significantly decreased from 53.4 to 13.3%. CONCLUSIONS: Although the present study is preliminary, the results show that co-treatment of lansoprazole with corticosteroids prevents ONFH development. Lansoprazole may be both safe and effective in preventing osteonecrosis of the femoral head in patients needing corticosteroid treatment.

Interleukin 5-producing ST2+ memory Th2 cells in IgG4-related dacryoadenitis and sialadenitis.

Objectives: Immunoglobulin (Ig) G4-related disease (IgG4-RD) is often complicated by allergic disorders. This study was conducted to investigate the mechanism of type 2 helper T-inflammation (Th2-inflammation) in IgG4-related dacryoadenitis and sialadenitis (IgG4-DS). Methods: We separated and analyzed the proportion of growth stimulation expressed gene 2 (ST2)+ memory Th2 cells among the peripheral blood mononuclear cells by flow cytometry in cases with IgG4-DS and healthy individuals. Finally, we identified the role of ST2+ memory Th2 cells in the involved tissues. Results: The proportion of circulating ST2+ memory Th2 cells was much higher in the patients with IgG4-DS than in the healthy controls. Abundant infiltration of ST2+ memory Th2 cells was detected in the involved salivary glands and lymph nodes, and these cells produced interleukin-5. Conclusion: We demonstrated that there is an increase of interleukin-5 producing ST2+ memory Th2 cells in the involved tissues in IgG4-DS. This subset of cells is considered to be an important player in inducing the inflammatory Th2 environment characteristic of IgG4-DS.

Successful Transcatheter Diagnosis and Medical Treatment of Right Atrial Involvement in IgG4-related Disease.

IgG4-related disease (IgG4-RD) is a fibro-inflammatory disorder characterized by lymphoplasmacytic infiltration of numerous IgG4-positive plasma cells, leading to fibrous thickening in the affected tissue. Typical cardiovascular manifestations of IgG4-RD are periaortitis, coronary arteritis, and pericarditis. Rare cases of myocardial involvement in IgG4-RD have been reported, but surgical resection or open biopsy was required for the diagnosis in those cases. Here, we report a case in which percutaneous transcatheter biopsy under the guidance of intracardiac echocardiography was useful for diagnosis of IgG4-RD manifested as an intracavitary right atrial mass, extending into the superior vena cava. Successful transcatheter diagnosis of myocardial involvement of IgG4-RD led to immediate favorable response to steroid therapy. Including the present case, previous IgG4-RD cases with myocardial involvement are reviewed to delineate its clinical characteristics.

Stage classification of IgG4-related dacryoadenitis and sialadenitis by the serum cytokine environment.

OBJECTIVES: Patients with immunoglobulin-G4 related disease (IgG4-RD) diagnosed according to the comprehensive diagnostic criteria (CDC) show varied therapeutic responses and prognoses. We assumed that there are clinical stages in IgG4-RD and have verified it using serum cytokine levels in the groups classified by lesion distribution. METHODS: Definite IgG4-related dacryoadenitis and sialadenitis (IgG4-DS) cases were divided according to the CDC for IgG4-RD into 11 cases with focal type and 30 cases with systemic type. The levels of serum interleukin (IL)-4, IL-5, IL-6, IL-10, IL-13, IL-15, IL-21, interferon (IFN)-α, IFN-γ, tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-ß1, and monocyte chemotactic protein (MCP)-1 were measured in healthy controls, allergic patients, probable IgG4-RD cases, and focal and systemic type cases. The cytokine environment was analyzed in each group. The 52 definite IgG4-RD cases were next classified into four groups with cluster analysis in terms of therapeutic responses and prognosis. The relationships between each cytokine level and therapeutic responses were also analyzed. RESULTS: Both serum IL-5 and IFN-α concentrations were very low in healthy controls, but they increased in the allergic cases, probable cases, and focal and systemic type cases. The level of serum IL-5 was significantly higher in definite cases than in healthy controls. The serum IL-5 level was also significantly increased in the groups with a poor prognosis than in the good prognosis group. CONCLUSION: These results suggest that there are clinical stages in IgG4-RD, and serum IL-5 play roles in the pathogenesis of IgG4-RD.

Predicting therapeutic response in IgG4-related disease based on cluster analysis.

To bring the clinical practice of immunoglobulin (Ig)G4-related disease (IgG4-RD) close to personalized medicine, we classified the patient groups and clarified the therapeutic responses of each group. A total of 147 patients enrolled in our registry were classified into four groups by cluster analysis with the software. The therapeutic responses and prognosis of each group were examined. The cluster analysis classified the subjects into four groups: Cluster 1, patients who presented with prominent hypergammaglobulinemia, elevated levels of serum IgG4, and hypocomplementemia; Cluster 2, patients who presented with eosinophilia, elevated concentrations of serum IgG, IgG4, and IgE, and in whom CRP tended to be positive; Cluster 3, patients with younger onset and serum levels of IgG, IgG4, and IgE and peripheral eosinophil counts lower than the other clusters; and Cluster 4, patients with elder onset and low peripheral eosinophil counts. The amounts of glucocorticoid for maintenance treatment were from 5 to 7 mg/d in all groups, but the amounts were significantly greater in Cluster 1 (patients with hypergammaglobulinemia, elevated levels of serum IgG4, and hypocomplementemia) than in Cluster 4 (elder onset patients, relatively low concentrations of peripheral eosinophils). With regard to the use of immunosuppressants and the relapse rate, there were high frequencies in Cluster 1 and Cluster 3 (younger onset patients who presented with mild elevations of serum IgG and IgG4). On the other hand, Cluster 4 showed a low rate of relapse and often could discontinue steroids. The present results suggest that personalized medicine could be provided in IgG4-RD by classifying patients based on their clinical features.

Circulating PD-1+CXCR5-CD4+ T cells underlying the immunological mechanisms of IgG4-related disease.

OBJECTIVE: The aim was to study the pathological role of lymphocytes with a peripheral T helper-cell-like phenotype (PD-1+CXCR5-CD4+) in IgG4-related disease (IgG4-RD). METHODS: PD-1+CXCR5-CD4+ T cells in the blood of patients with IgG4-RD (n = 53), patients with SS (n = 16) and healthy volunteers (n = 34) as controls were analysed by flow cytometry. Correlations between results obtained by flow cytometry and clinical parameters relevant to IgG4-RD were also analysed. RESULTS: The percentage and absolute number of PD-1+CXCR5- cells within total CD4+ T cells in IgG4-RD patients were significantly increased compared with those in healthy volunteers. Further analysis showed that there were marked positive correlations of the percentage of PD-1+CXCR5-CD4+ T cells with the serum level of IgG4 and the number of organs involved. Interestingly, granzyme A (GZMA)+ cells were enriched in PD-1+CXCR5-CD4+ T cells, and the percentage and absolute number of GZMA+PD-1+CXCR5-CD4+ T cells were significantly elevated in IgG4-RD patients. Although no obvious change was observed in the percentage of total CD4+ T cells, the percentage and absolute number of PD-1+CXCR5-CD4+ T cells decreased in accordance with a reduction of serum IgG4 level after treatment with glucocorticoids. CONCLUSION: In IgG4-RD, circulating CD4+ T-cell populations were composed of PD-1+CXCR5- cells, and the ratios of these cells were correlated with clinical manifestations of IgG4-RD. Further analysis of GZMA+PD-1+CXCR5-CD4+ T cells might lead to a deeper understanding of the pathogenesis of ectopic lymphoid follicles and the persistent inflammation in IgG4-RD.

Role of interleukin-32 in the mechanism of chronic inflammation in IgG4-related disease and as a predictive biomarker for drug-free remission.

OBJECTIVES: In immunoglobulin (Ig) G4-related disease (IgG4-RD), the mechanism of chronic inflammation and predictive factors for drug-free remission is still unclear. To examine the issues, we focused on tuberculosis, a chronic infection, and on the role of interleukin (IL)-32. METHODS: We examined the positive rate of QuantiFERON TB-2G (QFT-2G) in 126 patients with IgG4-RD, and compared with the rate in the general population. Furthermore, specimens of submandibular glands from the maintenance treatment group and drug-free group of IgG4-RD and specimens of small salivary glands from primary Sjögren's syndrome (SS) were stained with anti-IL-32 antibody and anti-protease-activated receptor 2 antibody, and the number of positive cells was compared between these groups. RESULTS: The positive rate of QFT-2G was 19.8% in IgG4-RD patients, which is higher than in the general population. The expression of IL-32 and PAR2 in the submandibular glands of the maintenance treatment group of IgG4-RD was significantly greater than that of the drug-free remission group and SS patients. CONCLUSIONS: This study indicates the possibility that IL-32 is associated with chronic inflammation and that it can be a predictive factor for drug-free remission in IgG4-RD.

Loss of interleukin-21 leads to atrophic germinal centers in multicentric Castleman's disease.

Both multicentric Castleman's disease (MCD) and immunoglobulin (Ig)G4-related disease (IgG4-RD) are systemic diseases, presenting with hypergammaglobulinemia and elevated serum levels of IgG4. However, with regard to histopathological findings, MCD shows atrophic germinal centers. On the other hand, expanded germinal centers are detected in IgG4-RD. We extracted germinal centers from specimens of each disorder by microdissection and analyzed the expression of mRNAs by real-time polymerase chain reaction to clarify the mechanisms underlying atrophied germinal centers in MCD. This analysis disclosed loss of interleukin (IL)-21 and B cell lymphoma (Bcl)-6 in the germinal centers of MCD. Loss of IL-21 is considered to be involved in the disappearance of Bcl-6 and leads to atrophied germinal centers in MCD.