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BACKGROUND: There is strong rationale for interference with T cell co-stimulation in IgG4-related disease (IgG4-RD), but the literature to evaluate this is limited to a single case report. METHODS: We conducted a ten-subject proof-of-concept trial of abatacept in active IgG4-RD. All subjects met the ACR/EULAR Classification Criteria for IgG4-RD. Subjects received subcutaneous abatacept 125 mg weekly for 24 weeks. Concurrent glucocorticoid treatment was permitted but if used had to be discontinued by week four. The primary endpoint, complete remission at 24 weeks, was defined as an IgG4-RD Responder Index score of 0. Peripheral blood mononuclear cells were collected at baseline, four weeks, and 12 weeks. B and T cell subsets were quantified using a 25-parameter flow cytometry panel. FINDINGS: The subjects’ median age was 68 years; seven subjects were male and nine were Caucasian. Baseline organ involvement was diverse with a median of 5 organs affected at the time of enrollment. The median serum IgG4 concentration was 597 mg/dL (IQR 304–913 mg/dL). Three subjects received concomitant prednisone at baseline. Six subjects (60%) had a disease response by week 12, five of whom maintained this response at week 24. Abatacept was stopped in the remaining five subjects (50%) due to flare (N = 1) or lack of response by week 12 (N = 4). Three subjects (30%) achieved the primary endpoint. Baseline proportions of unswitched memory B cells predicted responsiveness to abatacept. Reductions in serum IgE, circulating plasmablasts, and activated type 2 T follicular helper (T(FH2)) cells correlated with response to treatment. One adverse event (grade two thrombocytopenia) was attributed to abatacept. INTERPRETATION: Abatacept was associated with variable treatment responses in IgG4-RD. Half of the subjects achieved sustained treatment responses to abatacept alone, without glucocorticoids. Correlates of clinical response included reductions in serum IgE, circulating plasmablasts, and activated T(FH2) cells. Response to abatacept was predicted by higher proportions of unswitched memory B cells at baseline.

Objective To evaluate the efficacy and safety of ustekinumab (UST) in giant cell arteritis (GCA). Methods We conducted a prospective, open-label trial of UST in patients with active new-onset or relapsing GCA. Active disease was defined as the presence of GCA symptoms and elevation of erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP) level within 6 weeks of baseline. All patients received a 24-week prednisone taper and subcutaneous UST 90 mg at baseline and at weeks 4, 12, 20, 28, 36, and 44. The primary endpoint, prednisone-free remission, was defined as the absence of relapse through week 52 and normalization of the ESR and CRP level. Relapse was defined as the recurrence of GCA symptoms requiring treatment intensification. A sensitivity analysis excluding ESR/CRP level normalization from the prednisone-free remission definition was performed. Results The study enrolled 13 patients (target sample size 20). Enrollment was closed prematurely after 7 of the initial 10 patients relapsed. Five patients (39%) had new-onset disease. The initial prednisone doses were 20 mg (1 patient), 40 mg (9 patients), and 60 mg (3 patients). All patients entered disease remission within 4 weeks of baseline. Only 3 (23%) achieved the primary endpoint. Of the 10 patients (77%) who failed to achieve the primary endpoint, 7 relapsed after a mean period of 23 weeks. The remaining 3 patients met the alternative definition of prednisone-free remission that did not require ESR/CRP level normalization. One serious adverse event occurred. Conclusion UST combined with 24 weeks of prednisone was associated with a high rate of treatment failure in this prospective GCA trial.

Background Immunoglobulin G4-related disease (IgG4-RD) and systemic sclerosis (SSc) are rare autoimmune diseases characterized by the presence of CD4+ cytotoxic T cells in the blood as well as inflammation and fibrosis in various organs, but they have no established etiologies. Similar to other autoimmune diseases, the gut microbiome might encode disease-triggering or disease-sustaining factors. Methods The gut microbiomes from IgG4-RD and SSc patients as well as healthy individuals with no recent antibiotic treatment were studied by metagenomic sequencing of stool DNA. De novo assembly-based taxonomic and functional characterization, followed by association and accessory gene set enrichment analysis, were applied to describe microbiome changes associated with both diseases. Results Microbiomes of IgG4-RD and SSc patients distinctly separated from those of healthy controls: numerous opportunistic pathogenic Clostridium and typically oral Streptococcus species were significantly overabundant, while Alistipes, Bacteroides, and butyrate-producing species were depleted in the two diseases compared to healthy controls. Accessory gene content analysis in these species revealed an enrichment of Th17-activating Eggerthella lenta strains in IgG4-RD and SSc and a preferential colonization of a homocysteine-producing strain of Clostridium bolteae in SSc. Overabundance of the classical mevalonate pathway, hydroxyproline dehydratase, and fibronectin-binding protein in disease microbiomes reflects potential functional differences in host immune recognition and extracellular matrix utilization associated with fibrosis. Strikingly, the majority of species that were differentially abundant in IgG4-RD and SSc compared to controls showed the same directionality in both diseases. Compared with multiple sclerosis and rheumatoid arthritis, the gut microbiomes of IgG4-RD and SSc showed similar signatures; in contrast, the most differentially abundant taxa were not the facultative anaerobes consistently identified in inflammatory bowel diseases, suggesting the microbial signatures of IgG4-RD and SSc do not result from mucosal inflammation and decreased anaerobism. Conclusions These results provide an initial characterization of gut microbiome ecology in fibrosis-prone IgG4-RD and SSc and reveal microbial functions that offer insights into the pathophysiology of these rare diseases.

BACKGROUND: The efficacy of interleukin-6 receptor blockade in hospitalized patients with coronavirus disease 2019 (Covid-19) who are not receiving mechanical ventilation is unclear. METHODS: We performed a randomized, double-blind, placebo-controlled trial involving patients with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, hyperinflammatory states, and at least two of the following signs: fever (body temperature >38°C), pulmonary infiltrates, or the need for supplemental oxygen in order to maintain an oxygen saturation greater than 92%. Patients were randomly assigned in a 2:1 ratio to receive standard care plus a single dose of either tocilizumab (8 mg per kilogram of body weight) or placebo. The primary outcome was intubation or death, assessed in a time-to-event analysis. The secondary efficacy outcomes were clinical worsening and discontinuation of supplemental oxygen among patients who had been receiving it at baseline, both assessed in time-to-event analyses. RESULTS: We enrolled 243 patients; 141 (58%) were men, and 102 (42%) were women. The median age was 59.8 years (range, 21.7 to 85.4), and 45% of the patients were Hispanic or Latino. The hazard ratio for intubation or death in the tocilizumab group as compared with the placebo group was 0.83 (95% confidence interval [CI], 0.38 to 1.81; P = 0.64), and the hazard ratio for disease worsening was 1.11 (95% CI, 0.59 to 2.10; P = 0.73). At 14 days, 18.0% of the patients in the tocilizumab group and 14.9% of the patients in the placebo group had had worsening of disease. The median time to discontinuation of supplemental oxygen was 5.0 days (95% CI, 3.8 to 7.6) in the tocilizumab group and 4.9 days (95% CI, 3.8 to 7.8) in the placebo group (P = 0.69). At 14 days, 24.6% of the patients in the tocilizumab group and 21.2% of the patients in the placebo group were still receiving supplemental oxygen. Patients who received tocilizumab had fewer serious infections than patients who received placebo. CONCLUSIONS: Tocilizumab was not effective for preventing intubation or death in moderately ill hospitalized patients with Covid-19. Some benefit or harm cannot be ruled out, however, because the confidence intervals for efficacy comparisons were wide. (Funded by Genentech; ClinicalTrials.gov number, NCT04356937.).

We appreciate the opportunity to respond to the letter by Conway and Molloy regarding our recent manuscript entitled "Ustekinumab for the treatment of giant cell arteritis" [1]. Our results demonstrated that ustekinumab (UST) administered every 8 weeks was well tolerated but did not prevent disease relapse in a significant proportion of giant cell arteritis (GCA) patients when used in combination with 6 months of prednisone. We acknowledge that a small sample size and the lack of a control group are important limitations of our study and agree with Conway and Molloy that further research is needed to assess the utility of UST more definitively in GCA.

Objective: This pilot clinical trial examined the efficacy of blocking extracellular Galectin-3 (Gal-3) with modified citrus pectin (MCP), in patients suffering from knee osteoarthritis (OA). Methods: 50 patients were randomized in a 1:1 ratio to receive MCP or placebo at a dose of 4 g (5 capsules) twice daily for 12 weeks. Serum Gal-3 levels and OA severity were evaluated at baseline and 12 weeks. Gal-3 levels were detected by sandwich ELISA and OA severity was determined using WOMAC-knee, SF-36, and RAPID3 surveys during these visits. MCP tolerability was assessed by a basic metabolic panel during a week 6 follow up visit. Results: Patients enrolled in both the MCP treatment and placebo groups shared similar baseline characteristics in OA severity, serum Gal-3 levels, and pain management. Improvement across all surveys was noted independent of supplement or placebo treatment. No significant change in Gal-3 levels were observed in either cohort over the 12-week study. Conclusion: Treatment of knee OA with a 12-week course of MCP did not significantly improve disease burden compared to placebo. Keywords: Osteoarthritis, Galectin-3, Modified citrus pectin