Clinical and Molecular Findings After Autologous Stem Cell Transplantation or Cyclophosphamide for Scleroderma: Handling Missing Longitudinal Data.

OBJECTIVE: Among individuals with systemic sclerosis (SSc) randomized to cyclophosphamide (CYC) (n = 34) or hematopoietic stem cell transplantation (HSCT) (n = 33), we examined longitudinal trends of clinical, pulmonary function, and quality of life measures while accounting for the influence of early failures on treatment comparisons. METHODS: Assuming that data were missing at random, mixed-effects regression models were used to estimate longitudinal trends for clinical measures when comparing treatment groups. Results were compared to observed means and to longitudinal trends estimated from shared parameter models, assuming that data were missing not at random. Longitudinal trends for SSc intrinsic molecular subsets defined by baseline gene expression signatures (normal-like, inflammatory, and fibroproliferative signatures) were also studied. RESULTS: Available observed means for pulmonary function tests appeared to improve over time in both arms. However, after accounting for participant loss, forced vital capacity in HSCT recipients increased by 0.77 percentage points/year but worsened by -3.70/year for CYC (P = 0.004). Similar results were found for diffusing capacity for carbon monoxide and quality of life indicators. Results for both analytic models were consistent. HSCT recipients in the inflammatory (n = 20) and fibroproliferative (n = 20) subsets had superior long-term trends compared to CYC for pulmonary and quality of life measures. HSCT was also superior for modified Rodnan skin thickness scores in the fibroproliferative subset. For the normal-like subset (n = 22), superiority of HSCT was less apparent. CONCLUSION: Longitudinal trends estimated from 2 statistical models affirm the efficacy of HSCT over CYC in severe SSc. Failure to account for early loss of participants may distort estimated clinical trends over the long term.

Diminished cytokine-induced Jak/STAT signaling is associated with rheumatoid arthritis and disease activity.

Rheumatoid arthritis (RA) is a systemic and incurable autoimmune disease characterized by chronic inflammation in synovial lining of joints. To identify the signaling pathways involved in RA, its disease activity, and treatment response, we adapted a systems immunology approach to simultaneously quantify 42 signaling nodes in 21 immune cell subsets (e.g., IFNα→p-STAT5 in B cells) in peripheral blood mononuclear cells (PBMC) from 194 patients with longstanding RA (including 98 patients before and after treatment), and 41 healthy controls (HC). We found multiple differences between patients with RA compared to HC, predominantly in cytokine-induced Jak/STAT signaling in many immune cell subsets, suggesting pathways that may be associated with susceptibility to RA. We also found that high RA disease activity, compared to low disease activity, was associated with decreased (e.g., IFNα→p-STAT5, IL-10→p-STAT1) or increased (e.g., IL-6→STAT3) response to stimuli in multiple cell subsets. Finally, we compared signaling in patients with established, refractory RA before and six months after initiation of methotrexate (MTX) or TNF inhibitors (TNFi). We noted significant changes from pre-treatment to post-treatment in IFNα→p-STAT5 signaling and IL-10→p-STAT1 signaling in multiple cell subsets; these changes brought the aberrant RA signaling profiles toward those of HC. This large, comprehensive functional signaling pathway study provides novel insights into the pathogenesis of RA and shows the potential of quantification of cytokine-induced signaling as a biomarker of disease activity or treatment response.

Changes in biomarkers of inflammation and bone turnover and associations with clinical efficacy following infliximab plus methotrexate therapy in patients with early rheumatoid arthritis.

OBJECTIVE: To determine if changes in biomarkers of inflammation and bone turnover in response to treatment with infliximab plus methotrexate (MTX) versus MTX alone are associated with improvement in clinical measures of signs, symptoms, and structural damage in early rheumatoid arthritis. METHODS: Sera were collected from patients in the ASPIRE study who received 3 mg/kg (n = 48) or 6 mg/kg infliximab plus MTX (n = 55), or MTX alone (n = 41). Several baseline biomarker levels correlated with changes in median percentage of American College of Rheumatology improvement (ACR-N), 50% improvement in ACR response (ACR50), and van der Heijde-modified Sharp score (vdHSS) at Week 54. RESULTS: Infliximab plus MTX treatment resulted in more rapid decreases in levels of matrix metalloproteinase-3 (MMP-3), intercellular cell adhesion molecule-1, interleukin 8 (IL-8), and tumor necrosis factor-a than treatment with MTX alone. Baseline levels and decreases from baseline to Weeks 6 and 54 in MMP-3 correlated with improvement in ACR-N response at Week 54. An increase in IL-8 levels from baseline to Week 54 correlated with worsening in vdHSS at Week 54 in the MTX-alone group. Regression analysis of markers at baseline showed that MMP-3 was the only variable associated with ACR50 response and less worsening in vdHSS at Week 54. CONCLUSION: Treatment with infliximab plus MTX resulted in a rapid decrease in inflammation markers. MMP-3 levels at different timepoints were consistently associated with clinical improvements at Week 54 in the infliximab plus MTX group, while increases in IL-8 levels correlated with a worsening in vdHSS at Week 54 in the MTX-alone group.