Cardiovascular Risk in Rheumatoid Arthritis: Comparing TNF-α Blockade with Nonbiologic DMARDs

Background

Elevated tumor necrosis factor (TNF)-α likely contributes to the excess cardiovascular risk observed in rheumatoid arthritis. We compared the cardiovascular risk in rheumatoid arthritis patients starting a TNF-α blocking agent versus a nonbiologic disease-modifying antirheumatic drug (nbDMARD).

Methods

Subjects with rheumatoid arthritis participating in several different US insurance programs between 1998 and 2007 who received methotrexate were eligible. Those who added a TNF-α blocking agent were compared with subjects who added a nbDMARD in Cox regression models stratified by propensity score decile and adjusted for oral glucocorticoid dosage. We examined the composite cardiovascular end point of myocardial infarction, stroke, or coronary re-vascularization after 6 months.

Results

We compared 8656 new users of a nbDMARD with 11,587 new users of a TNF-α blocking agent with similar baseline covariates. Incidence rates per 100 person-years for the composite cardiovascular end point were 3.05 (95% confidence interval [CI], 2.54-3.65) for nbDMARDs and 2.52 (95% CI, 2.12-2.98) for TNF-α blocking agents. The hazard ratio (HR) for the TNF-α blocking agent compared with nbDMARD carrying the first exposure forward was 0.80 (95%, CI 0.62-1.04), while the HR for the as-treated analysis was 0.71 (95% CI, 0.52-0.97). The potential cardiovascular benefit of TNF-α blocking agents was strongest among individuals ≥65 years of age (HR 0.52; 95% CI, 0.34 -0.77; P for interaction = 0.075).

Conclusion

Among subjects with rheumatoid arthritis, TNF-α blocking agents may be associated with a reduced risk of cardiovascular events compared with an nbDMARD. Randomized controlled clinical trials should be considered to test this hypothesis.     

Inhibition of matrix metalloproteinase-9 expression by docosahexaenoic acid mediated by heme oxygenase 1 in 12-O-tetradecanoylphorbol-13-acetate-induced MCF-7 human breast cancer cells

Matrix metalloproteinase-9 (MMP-9) plays a crucial role in tumor metastasis. Previous studies showed that polyunsaturated fatty acids exhibit an anti-cancer effect in various human carcinoma cells, but the effect of docosahexaenoic acid (DHA) and linoleic acid (LA) on metastasis of breast cancer cells is not fully clarified. We studied the anti-metastasis potential of DHA and LA in 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced MCF-7 cells. We found that TPA (100 ng/ml) induced MMP-9 enzyme activity both dose- and time-dependently, and 200 μM DHA and LA significantly inhibited MMP-9 mRNA and protein expression, enzyme activity, cell migration, and invasion. Treatment with PD98059 (10 μM), wortmannin (10 μM), and GF109203X (0.5 μM) decreased TPA-induced MMP-9 protein expression and enzyme activity. TPA-induced activation of ERK1, Akt, and PKCδ was attenuated by DHA, whereas LA attenuated only ERK1 activation. GF109203X also suppressed ERK1 activation. EMSA showed that DHA, LA, PD98059, and wortmannin decreased TPA-induced NF-κB and AP-1 DNA-binding activity. Furthermore, DHA rather than LA dose-dependently increased HO-1 expression. HO-1 siRNA alleviated the inhibition by DHA of TPA-induced MMP-9 protein expression and enzyme activity in MCF-7 cells, and HO-1 knockdown reversed the DHA inhibition of cell migration. These results suggest that DHA and LA have both similar and divergent signaling pathways in the suppression of TPA-induced MCF-7 metastasis.     

Targeting tumor‐infiltrating Ly6G+ myeloid cells improves sorafenib efficacy in mouse orthotopic hepatocellular carcinoma

Sorafenib, a multikinase inhibitor with antiangiogenic activity, is an approved therapy for hepatocellular carcinoma (HCC). It is unclear whether the proinflammatory and immunosuppressive mechanisms may limit the therapeutic efficacy of sorafenib in HCC. We used a syngeneic mouse liver cancer cell line to establish orthotopic liver or subcutaneous tumors to study how proinflammatory and immunosuppressive mechanisms impact on the efficacy of sorafenib. We found sorafenib exhibited a potent therapeutic effect in subcutaneous tumors, but a less potent effect in orthotopic liver tumors. The protein levels of interleukin‐6 (IL‐6) and vascular endothelial growth factor A (VEGF‐A) were persistently elevated in orthotopic liver tumors, but not in subcutaneous tumors, treated with sorafenib. Likewise, the tumor‐infiltrating Ly6G⁺ myeloid‐derived suppressor cells (MDSCs) and immune suppressors were increased in orthotopic liver tumors, not in subcutaneous tumors, treated with sorafenib. The tumor‐infiltrating Ly6G⁺ MDSCs of sorafenib‐treated orthotopic liver tumors significantly induced IL‐10 and TGF‐β expressing CD4⁺ T cells, and downregulated the cytotoxic activity of CD8⁺ T cells. IL‐6, but not VEGF‐A, protected Ly6G⁺ MDSCs from sorafenib‐induced cell death in vitro. The combination of anti‐Ly6G antibody or anti‐IL‐6 antibody with sorafenib significantly reduced the cell proportion of Ly6G⁺ MDSCs in orthotopic liver tumors, enhanced the T cells proliferation and improved the therapeutic effect of sorafenib synergistically. Modulating tumor microenvironment through targeting tumor‐infiltrating Ly6G⁺MDSCs represents a potential strategy to improve the anti‐HCC efficacy of sorafenib.     

3D treatment planning system—Varian Eclipse for proton therapy planning

The capabilities of the Eclipse treatment planning system (TPS) (Varian Medical Systems, Palo Alto, CA) for proton therapy treatment planning are described. Various steps involved in the planning process to produce a 3-dimensional (3D) dose distribution both for the passive scattering and pencil beam scanning proton beam therapy are outlined. Mitigation of range and setup uncertainties through robust optimization is discussed. Use of verification plans for patient treatment field dosimetry quality assurance (QA) is presented. Limitations of the Eclipse TPS and future developments are discussed.     

Ultrastructural observations on beaded α-motoneuron dendrites

Beaded dendrites of 1α-motoneurons intracellularly labelled with horseradish peroxidase (HRP) were studied ultrastructurally in eight adult cats. For comparison, adjacent unlabelled beaded dendrites of unknown origin were also included in the study. Electron microscopy revealed no signs of degeneration or poor fixation according to common criteria. With the exception of the HRP-reaction product no difference in structure was observed between labelled and unlabelled beaded dendrites. Both the beads and their interconnecting segments were postsynaptic to boutons of normal appearance containing spherical (S-type boutons) or flattened vesicles (F-type boutons). The values for synaptic covering and synaptic packing density of the beaded dendritic regions, which usually were located in the periphery of the dendritic trees, were clearly lower than values obtained previously for cell bodies and proximal dendrites of a-motoneurons.