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ObjectiveTo evaluate changes in bone turnover and bone mineral density (BMD) in patients with rheumatoid arthritis (RA) receiving glucocorticoids, after discontinuation of denosumab for 12 months.MethodsWe conducted a randomized, double-blind, placebo-controlled, phase II study of RA patients. Patients received placebo, denosumab 60 mg, or denosumab 180 mg every 6 months for 12 months and were followed up for an additional 12 months after discontinuation, during which no bone loss prevention therapy was instituted. Changes from baseline in serum C-terminal telopeptide of type I collagen (CTX), serum procollagen type I N-terminal propeptide (PINP), and lumbar spine and total hip BMD were evaluated.ResultsIn this post hoc analysis of patients treated with glucocorticoids at study baseline (n = 82), levels of CTX and PINP decreased significantly from baseline in both denosumab groups. Following denosumab discontinuation, CTX returned to baseline and was not significantly different from the placebo group 6 and 12 months after discontinuation. Median percentage changes from baseline PINP in those treated with denosumab 60 mg were -0.16% and 15.3% at 6 and 12 months, respectively, after discontinuation (P = 0.062 and P = 0.017, versus placebo); corresponding changes with denosumab 180 mg were 9.0% and 75.8%, respectively (P = 0.018 and P = 0.002 versus placebo). Compared to placebo, lumbar spine and total hip BMD increased in patients receiving denosumab and returned to baseline 12 months after discontinuation. No osteoporotic fractures were reported during treatment or in the off-treatment period.ConclusionIn this analysis of short-term denosumab use in RA patients receiving glucocorticoids, denosumab discontinuation resulted in a gradual increase in bone turnover, which was associated with a return to baseline lumbar spine and total hip BMD.

Ileal strictures are the major indication for resective surgery in Crohn's disease (CD). We aimed to define ileal gene programs present at diagnosis linked with future stricturing behavior during five year follow-up, and to identify potential small molecules to reverse these gene signatures. Antimicrobial serologies and pre-treatment ileal gene expression were assessed in a representative subset of 249 CD patients within the RISK multicenter pediatric CD inception cohort study, including 113 that are unique to this report. These data were used to define genes associated with stricturing behavior and for model testing to predict stricturing behavior. A bioinformatics approach to define small molecules which may reverse the stricturing gene signature was applied. 19 of the 249 patients developed isolated B2 stricturing behavior during follow-up, while 218 remained B1 inflammatory. Using deeper RNA sequencing than in our prior report, we have now defined an inflammatory gene signature including an oncostatin M co-expression signature, tightly associated with extra-cellular matrix (ECM) gene expression in those who developed stricturing complications. We further computationally prioritize small molecules targeting macrophage and fibroblast activation and angiogenesis which may reverse the stricturing gene signature. A model containing ASCA and CBir1 serologies and a refined eight ECM gene set was significantly associated with stricturing development by year five after diagnosis (AUC (95th CI) = 0.82 (0.7-0.94)). An ileal gene program for macrophage and fibroblast activation is linked to stricturing complications in treatment naïve pediatric CD, and may inform novel small molecule therapeutic approaches.

Age-of-diagnosis associated variation in disease location and antimicrobial sero-reactivity has suggested fundamental differences in pediatric Crohn Disease (CD) pathogenesis. This variation may be related to pubertal peak incidence of ileal involvement and Peyer's patches maturation, represented by IFNγ-expressing Th1 cells. However, direct mucosal evidence is lacking. We characterize the global pattern of ileal gene expression and microbial communities in 525 treatment-naive pediatric CD patients and controls (Ctl), stratifying samples by their age-of-diagnosis. We show a robust ileal gene signature notable for higher expression of specific immune genes including GM-CSF and INFγ, and reduced expression of antimicrobial Paneth cell α-defensins, in older compared to younger patients. Reduced α-defensin expression in older patients was associated with higher IFNγ expression. By comparison, the CD-associated ileal dysbiosis, characterized by expansion of Enterobacteriaceae and contraction of Lachnospiraceae and Ruminococcaceae, was already established within the younger group and did not vary systematically with increasing age-of-diagnosis. Multivariate analysis considering individual taxa, however did demonstrate negative associations between Lachnospiraceae and IFNγ, and positive associations between Bacteroides and α-defensin expression. These data provide evidence for maturation of mucosal Th1 immune responses and loss of epithelial antimicrobial α-defensins which are associated with specific taxa with increasing age-of-diagnosis in pediatric CD.