Efficient detection of somatic UBA1 variants and clinical scoring system predicting patients with variants in VEXAS syndrome.

OBJECTIVES: To efficiently detect somatic UBA1 variants and establish a clinical scoring system predicting patients with pathogenic variants in VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome. METHODS: Eighty-nine Japanese patients with clinically suspected VEXAS syndrome were recruited [81 males and 8 females; median onset age (IQR) 69.3 years (62.1-77.6)]. Peptide nucleic acid-clamping PCR (PNA-PCR), regular PCR targeting exon 3 clustering UBA1 variants, and subsequent Sanger sequencing were conducted for variant screening. Partitioning digital PCR (pdPCR) or targeted amplicon deep sequencing (TAS) was also performed to evaluate the variant allele frequency (VAF). We developed our clinical scoring system to predict UBA1 variant-positive and ­negative patients and assessed the diagnostic value of our system using receiver operating characteristic (ROC) curve analysis. RESULTS: Forty patients with reported pathogenic UBA1 variants (40/89, 44.9%) were identified, including a case having a variant with VAF of 1.7%, using a highly sensitive method. Our clinical scoring system considering >50 years of age, cutaneous lesions, lung involvement, chondritis, and macrocytic anaemia efficiently predicted patients with UBA1 variants (the area under the curve for the scoring total was 0.908). CONCLUSIONS: Genetic screening with the combination of regular PCR and PNA-PCR detected somatic UBA1 variants with high sensitivity and specificity. Our scoring system could efficiently predict patients with UBA1 variants.

Intensive induction therapy combining tofacitinib, rituximab and plasma exchange in severe anti-melanoma differentiation-associatedprotein-5 antibody-positive dermatomyositis.

OBJECTIVES: Anti-melanoma differentiation-associated protein-5 (MDA5) autoantibodies (Abs) are associated with rapidly progressive interstitial lung disease (RP-ILD) in dermatomyositis (DM). Because the addition of plasma exchange (PE) and rituximab (RTX) to triple therapy is inadequate in severe cases, we treat such cases with intensive induction therapy (IIT) combining all these options with tofacitinib (TOF). In this study, we investigated the poor prognostic factors and the efficacy and safety of IIT. METHODS: Thirty-three patients diagnosed with anti-MDA5 Ab-positive DM in our institution between 2014 and 2021 were included. The clinical characteristics of poor prognosis were retrospectively analysed using principal component analysis (PCA), and the outcomes of IIT were analysed in terms of survival, assessed using the Kaplan-Meier test, and adverse events. RESULTS: Although triple therapy with RTX, PE, or intravenous immunoglobulin was administered before the introduction of IIT, eight of 12 RP-ILD cases with a ferritin level >400 ng/mL (mean, 2,342) died within a median of 2.5 months. PCA revealed distinct clusters for prognosis, and age and serum ferritin were leading predictors of the prognosis. IIT, consisting of combinations of triple therapy with higher doses of methylprednisolone, PE, RTX, and TOF, was applied to eight patients (mean ferritin, 3,558). Although two patients died even with these regimens, a significant improvement in survival was documented. Several IIT-related adverse events were observed, including viral and fungal infections and cytopenia. CONCLUSIONS: IIT significantly improved the survival of patients with severe anti-MDA5 Ab-positive RP-ILD. Although infections are noted, their benefits outweigh the risks in younger patients with high serum ferritin levels.

Development of severe colitis in Takayasu arteritis treated with tocilizumab.

Relapse of Takayasu arteritis (TAK) is frequent, and the use of biologics is required in refractory cases. Tocilizumab (TCZ), a biological agent used in TAK, is known to increase the incidence of diverticulitis in patients with rheumatoid arthritis. Adverse events of TCZ in TAK have been poorly recognised. This study aimed to investigate the occurrence of severe colitis among patients with TAK receiving TCZ. We enrolled 116 patients with TAK who met the criteria of the American College of Rheumatology and visited our department between 2018 and 2020. The occurrence of severe colitis and its clinical characteristics were retrospectively evaluated. TCZ was introduced in 34 of 116 patients (29.3%). Severe colitis that required hospitalisation was observed in three of the 34 patients receiving TCZ (8.8%). All patients were female and had Numano type V artery lesions, and the ascending colon was commonly affected. Wide lesions that reached the sigmoid colon, colonic perforation, bacteraemia, or positive stool cultures were observed in some patients. All patients received antibiotics and intestinal rest, and TCZ was resumed in one patient. IL-6 plays a physiological role in the intestine, including recovery from ischaemic damage. In addition to infectious aetiology, blocking the physiological roles of IL-6 by TCZ is considered important for the development of colitis in TAK. Severe colitis is an important adverse event in patients with TAK who receive TCZ. The risk of bloodstream infection associated with colitis should be recognised, especially in patients who have undergone vascular surgery. Key Points • Severe colitis was observed in 8.8% of patients with TAK receiving tocilizumab • Patients had type V artery lesions and ascending colon involvement and were under long-term use of corticosteroids • Inhibition of the physiological roles of IL-6 in the intestinal tract might also be involved.

TRAF5 Deficiency Ameliorates the Severity of Dextran Sulfate Sodium Colitis by Decreasing TRAF2 Expression in Nonhematopoietic Cells.

TNFR-associated factor 5 (TRAF5) is a cytosolic adaptor protein and functions as an inflammatory regulator. However, the in vivo function of TRAF5 remains unclear, and how TRAF5 controls inflammatory responses in the intestine is not well understood. In this study, we found that intestinal epithelial cells from Traf5-/- mice expressed a significantly lower level of NF-κB-regulated proinflammatory genes, such as Tnf, Il6, and Cxcl1, as early as day 3 after dextran sulfate sodium (DSS) exposure when compared with wild-type mice. The intestinal barrier integrity of DSS-treated Traf5-/- mice remained intact at this early time point, and Traf5-/- mice showed decreased body weight loss and longer colon length at later time points. Surprisingly, the protein level of TRAF2, but not TRAF3, was reduced in colon tissues of Traf5-/- mice after DSS, indicating the requirement of TRAF5 for TRAF2 protein stability in the inflamed colon. Experiments with bone marrow chimeras confirmed that TRAF5 deficiency in nonhematopoietic cells caused the attenuated colitis. Our in vitro experiments demonstrated that proinflammatory cytokines significantly promoted the degradation of TRAF2 protein in Traf5-/- nonhematopoietic cells in a proteasome-dependent manner. Collectively, our data suggest a novel regulatory function of TRAF5 in supporting the proinflammatory function of TRAF2 in nonhematopoietic cells, which may be important for acute inflammatory responses in the intestine.

IQ motif-containing GTPase-activating protein 1 is essential for the optimal maintenance of lung ILC2s.

Group 2 innate lymphoid cells (ILC2s) play critical roles in type 2 immunity and are crucial for pathogenesis of various types of inflammatory disease. IQ motif-containing GTPase-activating protein 1 (IQGAP1) is a ubiquitously expressed scaffold protein that is involved in multiple cellular functions such as cell survival and trafficking. While the roles for IQGAP1 in T and B lymphocytes have been uncovered, the physiological significance of IQGAP1 in innate lymphocytes remains to be elucidated. In the current study, we demonstrate that using bone marrow chimeras, the deficiency of IQGAP1 caused an impaired survival of lung ILC2s in a cell-intrinsic manner and that Iqgap1-/- mice displayed decreased accumulation of ILC2s after administration of papain and thereby reduced the pathology of the disease. Moreover, Iqgap1-/- ILC2s showed a significantly enhanced apoptosis as compared to wild-type ILC2s under both steady-state and inflammatory conditions. Together these results identify for the first time that IQGAP1 is essential for homeostasis of ILC2s in the lung.

TNF receptor associated factor 5 controls oncostatin M-mediated lung inflammation.

Oncostatin M (OSM) is involved in pathogenesis of several human inflammatory diseases including lung inflammation and fibrosis. Although accumulating evidence indicates that OSM mediates lung inflammation, the precise mechanism for OSM on lung inflammation still remains unclear. In this study, we found that OSM receptor was abundantly expressed on endothelial and stromal/fibroblast cells in the lung of mice. In vitro stimulation with OSM upregulated vascular cell adhesion molecule-1 (VCAM-1), which promotes eosinophil infiltration in the lung tissues, on freshly-isolated lung stromal/fibroblast cells from wild-type mice. However, these cells from TNF receptor associated factor 5 (TRAF5)-deficient mice failed to show the increase in VCAM-1 expression after OSM stimulation. Furthermore, Traf5-/- mice showed markedly attenuated lung inflammation in terms of eosinophil infiltration upon intranasal administration with OSM as compared to wild-type mice. These results indicate that TRAF5 is crucially involved in OSM-mediated lung inflammation probably by inducing lung stromal/fibroblast cell activation.

Long-term follow-up of 124 patients with polymyositis and dermatomyositis: Statistical analysis of prognostic factors.

OBJECTIVES: The aims of this study were to clarify the long-term outcome of patients with polymyositis and dermatomyositis (PM/DM) and to elucidate prognostic factors using statistical analysis. METHODS: We enrolled patients with PM/DM who visited our department between 1990 and 2014. Diagnoses of PM/DM and clinically amyopathic DM were based on the definitions of Bohan and Peter, and Sontheimer, respectively. We also obtained clinical data, such as age of onset, sex, medications, and presence of interstitial lung disease and malignancies, as well as laboratory tests, including the values of creatine kinase, KL-6, and ferritin. The follow-up was conducted until June 2014. RESULTS: A total of 124 patients (PM: 46, DM: 78) were enrolled. The mean age of onset was 53.5 years, and females were predominant (64.5%). Overall survival rates were 93%, 86%, and 78% for 1, 5, and 10 years, respectively. The survival rates were significantly lower in patients with higher age of onset, with malignancies, and with hyperferritinemia in univariate analysis; however, multivariate analysis identified age of onset and serum ferritin as the most significant prognostic factors. CONCLUSIONS: Our study indicates that when age of onset and serum ferritin are used in combination, we can predict prognosis of patients with PM/DM.

Retrospective analysis of 95 patients with large vessel vasculitis: a single center experience.

AIM: Although Takayasu arteritis (TAK) and giant cell arteritis (GCA) have been considered as distinct disease entities, similarities of these diseases have been recently reported. However, little data is available regarding this issue in Japanese patients with TAK and GCA. In addition, the classification criteria for TAK established in 1990 by the American College of Rheumatology (ACR) have been criticized due to the age restriction for disease onset (≤ 40 years). Thus, we aimed to compare the clinical characteristics of Japanese patients with TAK and those with GCA and to clarify whether clinical differences existed between patients with early-onset (≤ 40 years) and late-onset (> 40 years) TAK. METHODS: We enrolled 86 patients with TAK and nine with GCA who visited our department from 1990 to 2014. The diagnoses of TAK and GCA were based on the criteria of the Japanese Circulation Society and the ACR, respectively. RESULTS: Mean ages at onset for TAK and GCA were 36.4 and 71.0 years, respectively. Patients with TAK had significantly higher incidences of aortic regurgitation and carotid and subclavian arterial involvement, lower frequencies of polymyalgia rheumatica, and better prognoses than those with GCA. In contrast, the clinical characteristics, distribution of arterial lesions, treatments administered, and prognoses of patients with early- and late-onset TAK were comparable. CONCLUSIONS: These results suggested that TAK and GCA differed substantially, and that the age restriction (≤ 40 years) may not be necessary for the diagnosis of TAK.