Dataset Information

Exploring the existence of a stayer population with mover-stayer counting process models: application to joint damage in psoriatic arthritis.

ABSTRACT: Many psoriatic arthritis patients do not progress to permanent joint damage in any of the 28 hand joints, even under prolonged follow-up. This has led several researchers to fit models that estimate the proportion of stayers (those who do not have the propensity to experience the event of interest) and to characterize the rate of developing damaged joints in the movers (those who have the propensity to experience the event of interest). However, when fitted to the same data, the paper demonstrates that the choice of model for the movers can lead to widely varying conclusions on a stayer population, thus implying that, if interest lies in a stayer population, a single analysis should not generally be adopted. The aim of the paper is to provide greater understanding regarding estimation of a stayer population by comparing the inferences, performance and features of multiple fitted models to real and simulated data sets. The models for the movers are based on Poisson processes with patient level random effects and/or dynamic covariates, which are used to induce within-patient correlation, and observation level random effects are used to account for time varying unobserved heterogeneity. The gamma, inverse Gaussian and compound Poisson distributions are considered for the random effects.

SUBMITTER: Yiu S

PROVIDER: S-EPMC5503139 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:To assess whether secukinumab treatment in patients with active psoriatic arthritis (PsA) is associated with sustained inhibition of radiographic progression.In this phase III, double-blind, placebo-controlled study, 606 patients with PsA were randomized to receive intravenous (IV) secukinumab at a dose of 10 mg/kg (weeks 0, 2, 4) followed by subcutaneous secukinumab at a dose of 150 mg or 75 mg (the IV?150 mg and IV?75 mg groups, respectively) or placebo. Patients were stratified according to prior anti-tumor necrosis factor (anti-TNF) exposure (71% were anti-TNF naive). At week 16, placebo-treated patients who had at least a 20% reduction in the tender and swollen joint counts (responders) continued to receive placebo until week 24; nonresponders were re-randomized to receive secukinumab at a dose of 150 mg or 75 mg. The modified total Sharp/van der Heijde score (SHS) was determined at baseline, week 16 or 24, and week 52.In the overall population, radiographic progression was inhibited through 52 weeks; efficacy was demonstrated for both erosion and joint space narrowing scores and in patients who switched from placebo to secukinumab at week 24. Subgroup analyses showed that secukinumab reduced radiographic progression at week 24, regardless of previous anti-TNF treatment. Among anti-TNF-naive patients, the mean changes from baseline to week 24 in the modified total SHS were 0.05 in the pooled secukinumab group and 0.57 in the placebo group; among patients with an inadequate response or intolerance to anti-TNF treatment, the mean changes were 0.16 and 0.58, respectively. Anti-TNF-naive patients showed negligible progression through week 52. Inhibition of structural damage was observed through week 52 irrespective of concomitant methotrexate use. A high proportion of patients receiving secukinumab showed no progression (change in SHS of ??0.5) from baseline to week 24 (82.3% of the IV?150 mg group and 92.3% of the IV?75 mg group) and from week 24 to week 52 (85.7% of the IV?150 mg group and 85.8% of the IV?75 mg group).Secukinumab inhibited radiographic progression over 52 weeks of treatment in patients with active PsA.

Project description:Psoriatic arthritis (PsA) is associated with HLA class I genes, in contrast to the association with HLA class II in rheumatoid arthritis (RA). Since IL-17+ cells are considered important mediators of synovial inflammation, we sought to determine whether IL-17-producing CD8+ T cells may be found in the joints of patients with PsA and whether these cells might contribute to the disease process.Mononuclear cells from paired samples of synovial fluid (SF) and peripheral blood (PB) from patients with PsA or patients with RA were stimulated ex vivo, and CD4- T cells were examined by flow cytometry for cytokine expression, cytotoxic markers, and frequencies of ?/? or mucosal-associated invariant T cells. Clinical measures of arthritis activity (C-reactive protein [CRP] level, erythrocyte sedimentation rate [ESR], Disease Activity Score in 28 joints [DAS28]) and power Doppler ultrasound (PDUS) scores for the presence of active synovitis in the aspirated knee were recorded and assessed for correlations with immunologic markers.Within the CD3+ T cell compartment, both IL-17+CD4- (predominantly CD8+) and IL-17+CD4+ T cells were significantly enhanced in the SF compared to the PB of patients with PsA (P = 0.0003 and P = 0.002, respectively; n = 21), whereas in patients with RA, only IL-17+CD4+ T cells were increased in the SF compared to the PB (P = 0.008; n = 14). The frequency of IL-17+CD4- T cells in PsA SF was positively correlated with the CRP level (r = 0.52, P = 0.01), ESR (r = 0.59, P = 0.004), and DAS28 (r = 0.52, P = 0.01), and was increased in patients with erosive disease (P < 0.05). In addition, the frequency of IL-17+CD4- T cells positively correlated with the PDUS score, a marker for active synovitis (r = 0.49, P = 0.04).These results show, for the first time, that the PsA joint, but not the RA joint, is enriched for IL-17+CD8+ T cells. Moreover, the findings reveal that the levels of this T cell subset are correlated with disease activity measures and the radiographic erosion status after 2 years, suggesting a previously unrecognized contribution of these cells to the pathogenesis of PsA.

Dataset Information

Exploring the existence of a stayer population with mover-stayer counting process models: application to joint damage in psoriatic arthritis.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets