The risk of venous thromboembolism in patients with multiple sclerosis: the Clinical Practice Research Datalink.

BACKGROUND: In patients with multiple sclerosis (MS), disability and autoinflammatory processes may result in an increased risk of venous thromboembolism (VTE) OBJECTIVE: To evaluate the risk of VTE associated with MS. METHODS: We conducted an observational-cohort study within the Clinical Practice Research Datalink (1987-2009) linked to the National Registry of Hospitalizations (1997-2008). At the time of MS diagnosis, a comparison cohort (N = 33 370) without a recorded MS diagnosis during the study period was matched (6:1) to the MS cohort (n = 5566) by birth year, sex, and practice. Subjects were followed from the index date until the occurrence of VTE, end of data collection, migration, or death, whichever came first. Cox proportional-hazards models were used to derive adjusted hazard ratios and 95% confidence intervals for VTE associated with MS and VTE risk factors within the MS cohort. Time-dependent adjustments were made for age, comorbidity, and medication use. RESULTS: Compared with the comparison cohort, a 2.6-fold increased risk of VTE was observed for MS patients (adjusted hazard ratio 2.56, 95% confidence interval 2.06-3.20). A prior VTE event, varicose veins, obesity, and major trauma were found to be associated with an increased risk of VTE within the MS population. Moreover, the risk of VTE was increased in MS patients with recent records indicating immobility, spasticity, glucocorticoid use, or disability. CONCLUSIONS: Patients with MS had an increased risk of VTE. Furthermore, our results provide evidence that this association is, at least in part, mediated through an increased prevalence of VTE risk factors in MS patients.

Early results from the ENGAGE registry: real-world performance of the Endurant Stent Graft for endovascular AAA repair in 1262 patients.

OBJECTIVE: The ENGAGE registry was undertaken to examine the real-world outcome after endovascular abdominal aortic aneurysm (AAA) repair (EVAR) with the Endurant Stent Graft in a large, contemporary, global series of patients. METHODS: From March 2009 to April 2011, 1262 AAA patients (89.6% men; mean age 73.1 years, range 43-93 years) were enrolled from 79 sites in 30 countries and treated with Endurant. Results are described following the reporting standards for EVAR. Follow-up data were tabulated for all 1262 patients at a 30-day follow-up and for the first 500 patients at a 1-year follow-up. RESULTS: Intra-operative technical success was achieved in 99.0% of cases. Within 30 days, adverse events were reported in 3.9% of patients, including a 1.3% mortality rate. Type-I or -III endoleaks were identified in 1.5% of cases. Estimated overall survival, aneurysm-related survival and freedom from secondary interventions at 1 year were 91.6%, 98.6% and 95.1%, respectively. At 1 year, aneurysm size increased ≥ 5 mm in 2.8% and decreased ≥ 5 mm in 41.3% of cases. CONCLUSION: Early results from this real world, global experience are promising and indicate that endovascular AAA repair with the Endurant Stent Graft is safe and effective across different geographies and standards of practice. Longer-term follow-up is necessary to assess durability of these results.

Essential role for TRPV1 in stress-induced (mast cell-dependent) colonic hypersensitivity in maternally separated rats.

Irritable bowel syndrome is in part characterized by an increased sensitivity to colonic distension. Stress is an important trigger factor for symptom generation. We hypothesized that stress induces visceral hypersensitivity via mast cell degranulation and transient receptor ion channel 1 (TRPV1) modulation. We used the rat model of neonatal maternal separation (MS) to investigate this hypothesis. The visceromotor response to colonic distention was assessed in adult MS and non-handled (NH) rats before and after acute water avoidance (WA) stress. We evaluated the effect of the mast cell stabilizer doxantrazole, neutralizing antiserum against the mast cell mediator nerve growth factor (NGF) and two different TRPV1 antagonists; capsazepine (non-specific) and SB-705498 (TRPV1-specific). Immunohistochemistry was used to assess post-WA TRPV1 expression in dorsal root ganglia and the presence of immunocytes in proximal and distal colon. Retrograde labelled and microdissected dorsal root ganglia sensory neurons were used to evaluate TRPV1 gene transcription. Results showed that acute stress induces colonic hypersensitivity in MS but not in NH rats. Hypersensitivity was prevented by prestress administration of doxantrazole and anti-NGF. Capsazepine inhibited and SB-705498 reversed poststress hypersensitivity. In MS rats, acute stress induced a slight increase in colonic mast cell numbers without further signs of inflammation. Post-WA TRPV1 transcription and expression was not higher in MS than NH rats. In conclusion, the present data on stress-induced visceral hypersensitivity confirm earlier reports on the essential role of mast cells and NGF. Moreover, the results also suggest that TRPV1 modulation (in the absence of overt inflammation) is involved in this response. Thus, mast cells and TRPV1 are potential targets to treat stress-induced visceral hypersensitivity.

Activation of the cannabinoid 2 (CB2) receptor inhibits murine mesenteric afferent nerve activity.

Abstract Cannabinoid 2 (CB2) receptors have both antinociceptive and antihypersensitivity effects, although the precise mechanisms of action are still unclear. In this study, the modulatory role of CB2 receptors on the mesenteric afferent response to the endogenous immunogenic agent bradykinin (BK) was investigated. Mesenteric afferent recordings were obtained from anaesthetized wild-type and CB2(-/-) mice using conventional extracellular recording techniques. Control responses to BK were obtained in all experiments prior to administration of either CB2 receptor agonist AM1241, or AM1241 plus the CB2 receptor antagonist AM630. Bradykinin consistently evoked activation of mesenteric afferents (n = 32). AM1241 inhibited the BK response in a dose dependent manner. In the presence of AM630 (10 mg kg(-1)), however, AM1241 (10 mg kg(-)1) had no significant effect on the BK response. Moreover, AM1241 had also no significant effect on the BK response in CB2(-/-) mice. Activation of the CB2 receptor inhibits the BK response in mesenteric afferents, demonstrating that the CB2 receptor is an important regulator of neuroimmune function. This may be a mechanism of action for the antinociceptive and antihypersensitive effects of CB2 receptor agonists.