Differential microvasculature dysfunction in living kidney donor transplant recipients: nondialyzed versus dialyzed chronic kidney disease patients.

We hypothesized that there was differential vasomotor dysfunction in the microcirculation between nondialyzed and dialyzed chronic kidney disease (CKD) patients. During live donor kidney transplantation procedures, skin arterioles (SkA; internal diameter = 120 +/- 5 microm) from donors (n = 27) and recipients (nondialysis = 15; dialysis = 20) were dissected from the abdominal wall at the incision site. In vivo aortic pulse wave velocity (PWV) was also measured. In the in vitro isometric force measurement, nondialyzed SkA exhibited comparable contraction to donor SkA, whereas dialyzed SkA had 60 and 40-50% increase in contraction in response to depolarization and agonist (that is, phenylephrine, serotonin and endothelin-1) stimulation, respectively. The acetylcholine-induced relaxation in the nondialyzed SkA was decreased by 50% compared with dialyzed SkA. However, pre-incubation with superoxide dismutase greatly enhanced the relaxation response in the nondialyzed, but not in the dialyzed SkA and donor SkA. Pre-incubation with N(G)-nitro-L-arginine methyl ester (L-NAME) elevated the resting tension and left-shifted the concentration response curve of phenylephrine-stimulated contraction in the donor-SkA. L-NAME only increased the resting tension in the nondialyzed vessel. In vitro stiffness positively correlated with PWV (R(2) = 0.302, p = 0.001), and dialyzed SkA was 60% stiffer than nondialyzed and donor SkA. The acetylcholine relaxation was negatively correlated with PWV in donors and recipients (R(2) = 0.282, p = 0.01). In conclusion, we have uniquely demonstrated differential microvasculature dysfunction between nondialyzed and dialyzed CKD patients.

Inducible nitric oxide synthase activity is increased in patients with rheumatoid arthritis and contributes to endothelial dysfunction.

BACKGROUND: Recent in vitro studies suggest that inducible nitric oxide synthase (iNOS) activity mediates endothelial dysfunction. Rheumatoid arthritis (RA) is a chronic inflammatory condition and is associated with endothelial dysfunction and increased risk of cardiovascular disease. The aim of the study was to establish the contribution of iNOS to endothelial function. METHODS: Forearm blood flow (FBF) was measured during intra-arterial infusions of acetylcholine (ACh), sodium nitroprusside (SNP), N(G)-monomethyl-l-arginine (l-NMMA) and aminoguanidine (AG) in 12 RA patients and 13 healthy control subjects. Levels of C-reactive protein (CRP) and myeloperoxidase (MPO) were assessed. FBF data are presented as mean percentage changes in the ratio (infused/control arm) of FBF + or - SEM. RESULTS: FBF response to ACh was reduced in patients with RA compared to controls (179 + or - 29 v. 384 + or - 72%, respectively; P=0.01), but SNP response was not (P=0.5). FBF response to AG differed between patients and controls (-15 + or - 2% v. 13 + or - 4%, respectively; P<0.001), whereas the response to l-NMMA did not (P=0.4). In a multiple regression model log CRP, AG response and LDL were found to be independent predictors of endothelial function (R(2)=0.617, P<0.001). CONCLUSION: RA patients have endothelial dysfunction and increased iNOS activity in comparison to controls. Furthermore, CRP and iNOS activity were independently associated with endothelial function. Our data demonstrates that inflammation is a key mediator in a process of endothelial dysfunction possibly via activation of iNOS and increased production of MPO.

Ezetimibe and simvastatin reduce inflammation, disease activity, and aortic stiffness and improve endothelial function in rheumatoid arthritis.

OBJECTIVES: The aim of this study was to investigate the effect of simvastatin and ezetimibe on inflammation, disease activity, endothelial dysfunction, and arterial stiffness in a cohort of rheumatoid arthritis (RA) patients. BACKGROUND: Rheumatoid arthritis is a chronic inflammatory condition associated with increased cardiovascular risk. Statins reduce inflammation and disease activity in RA patients, but whether this is due to pleiotropism or cholesterol lowering per se is unclear. METHODS: Twenty patients received 20 mg simvastatin or 10 mg ezetimibe each for 6 weeks in a randomized double-blind crossover study. Disease activity, blood pressure, aortic pulse wave velocity (PWV), brachial artery flow-mediated dilation (FMD), and serum inflammatory markers were measured before and after each treatment. RESULTS: Both ezetimibe and simvastatin significantly reduced total cholesterol (-0.62 +/- 0.55 mmol/l and -1.28 +/- 0.49 mmol/l, respectively; p < 0.001), low-density lipoprotein cholesterol (-0.55 +/- 0.55 mmol/l and -1.28 +/- 0.49 mmol/l; p < 0.0001), and C-reactive protein (-5.35 +/- 9.25 mg/l and -5.05 +/- 6.30 mg/l; p < 0.001). Concomitantly, Disease Activity Score (-0.55 +/- 1.01 and -0.67 +/- 0.91; p = 0.002), aortic PWV (-0.69 +/- 1.15 m/s and -0.71 +/- 0.71 m/s; p = 0.001), and FMD (1.37 +/- 1.17% and 2.51 +/- 2.13%; p = 0.001) were significantly improved by both drugs. CONCLUSIONS: This study demonstrates that both ezetimibe and simvastatin reduce disease activity and inflammatory markers to a similar extent in patients with RA. Therapy is also associated with a concomitant reduction in aortic PWV and improvement in endothelial function. This suggests that cholesterol lowering per se has anti-inflammatory effects and improves vascular function in RA.

Isolated systolic hypertension is characterized by increased aortic stiffness and endothelial dysfunction.

Isolated systolic hypertension is associated with increased cardiovascular risk. It is thought to result from large artery stiffening, which is determined by structural components within the vasculature but also by functional factors including NO and endothelin-1. We hypothesized that endothelial dysfunction would account for increased arterial stiffness in patients with isolated systolic hypertension. The aim of this study was to investigate the relationship between endothelial function and arterial stiffness in these patients along with control subjects. We studied 113 subjects: 35 patients with isolated systolic hypertension (mean age+/-SD: 68+/-6 years), 30 age-matched control subjects (65+/-5 years), and 48 young control subjects (37+/-9 years). Aortic pulse wave velocity (PWV) was derived by sequential carotid/femoral waveform recordings. Conduit artery endothelial function was determined by flow-mediated dilatation. Aortic PWV was higher (9.65+/-2.56 m/s versus 8.26+/-0.85 m/s; P=0.009), and flow-mediated dilatation was lower (2.67+/-1.64% versus 4.79+/-3.1%; P=0.03) in patients with isolated systolic hypertension compared with age-matched control subjects. Similarly, aortic PWV was also higher, and flow-mediated dilatation lower, in older versus young control subjects (8.26+/-0.85 m/s versus 7.09+/-1.01 m/s and 4.79+/-3.1% versus 6.94+/-2.7%; P=0.004 for both). Overall, aortic PWV correlated inversely with flow-mediated dilatation (r=-0.3; P=0.001), which remained significant after adjustment for confounding factors (P=0.01). Patients with isolated systolic hypertension have higher aortic PWV and decreased endothelial function compared with age-matched control subjects. Our results suggest that endothelial function contributes significantly to increased arterial stiffness in patients with isolated systolic hypertension and with age.

Rheumatoid arthritis is associated with increased aortic pulse-wave velocity, which is reduced by anti-tumor necrosis factor-alpha therapy.

BACKGROUND: Rheumatoid arthritis (RA) is associated with increased cardiovascular risk, which is not explained by traditional cardiovascular risk factors but may be due in part to increased aortic stiffness, an independent predictor of cardiovascular mortality. In the present study, our aim was to establish whether aortic stiffness is increased in RA and to investigate the relationship between inflammation and aortic stiffness. In addition, we tested the hypothesis that aortic stiffness could be reduced with anti-tumor necrosis factor-alpha (TNF-alpha) therapy. METHODS AND RESULTS: Aortic pulse-wave velocity (PWV), augmentation index, and blood pressure were measured in 77 patients with RA and in 142 healthy individuals. Both acute and chronic inflammatory measures and disease activity were determined. The effect of anti-TNF-alpha therapy on PWV and endothelial function was measured in 9 RA patients at 0, 4, and 12 weeks. Median (interquartile range) aortic PWV was significantly higher in subjects with RA than in control subjects (8.35 [7.14 to 10.24] versus 7.52 [6.56 to 9.18] m/s, respectively; P = 0.005). In multiple regression analyses, aortic PWV correlated independently with age, mean arterial pressure, and log-transformed C-reactive protein (R2 = 0.701; P < 0.0001). Aortic PWV was reduced significantly by anti-TNF-alpha therapy (8.82+/-2.04 versus 7.94+/-1.86 versus 7.68+/-1.56 m/s at weeks 0, 4, and 12, respectively; P < 0.001); concomitantly, endothelial function improved. CONCLUSIONS: RA is associated with increased aortic stiffness, which correlates with current but not historical measures of inflammation, suggesting that increased aortic stiffness may be reversible. Indeed, anti-TNF-alpha therapy reduced aortic stiffness to a level comparable to that of healthy individuals. Therefore, effective control of inflammation may be of benefit in reducing cardiovascular risk in patients with RA.

Immunotherapy for autoimmune and inflammatory renal diseases.

Immune-mediated renal disease (IMRD) accounts for 20 - 30% of the cases of end stage renal failure. It frequently occurs in the context of multi-system autoimmune disorders, including systemic lupus erythematosus (SLE) and primary systemic vasculitis. Current therapies are partially effective and comprise the combination of steroids with an immunosuppressive, such as cyclophosphamide. Their toxicity contributes to the morbidity and mortality of these disorders, and long-term treatment is necessary to prevent relapse. There is a clear need for better-targeted, more effective and less toxic therapy. Advances in our understanding of the immunopathogenesis of inflammatory autoimmune renal disease have identified potential targets for newer agents and have improved the monitoring of therapeutic responses. Recent experience with newer therapies in IMRD is reviewed. This has typically involved small, non-randomised, open-label trials and has addressed reversible features of disease activity. Larger, randomised comparisons to standard therapy are needed along with assessment of long-term efficacy and safety.

Outcome of ANCA-associated renal vasculitis: a 5-year retrospective study.

BACKGROUND: Renal involvement is frequently present in antineutrophil cytoplasmic autoantibody (ANCA)-associated systemic vasculitis and is an important cause of end-stage renal failure (ESRF). METHODS: This retrospective, multicenter, sequential cohort study reports presenting features and outcome of 246 new patients diagnosed in London, UK, between 1995 and 2000. RESULTS: Diagnostic subgroups were microscopic polyangiitis, 120 patients (49%); Wegener's granulomatosis (WG), 82 patients (33%); renal-limited vasculitis, 33 patients (13.5%); and Churg-Strauss angiitis, 11 patients (4.5%). Median age was 66 years, 57% were men, and median creatinine level at presentation was 3.87 mg/dL (342 micromol/L). ANCA was present in 92%. Cumulative patient survival at 1 and 5 years was 82% and 76%, respectively. Mortality was associated with age older than 60 years (P < 0.001), development of ESRF (P < 0.001), initial creatinine level greater than 2.26 mg/dL (200 micromol/L; P = 0.01), and sepsis (P < 0.048). ESRF occurred in 68 patients (28%), of whom 47% died. Fifty-six patients who presented with a creatinine level greater than 5.65 mg/dL (500 micromol/L) survived, and 31 patients (55%) achieved dialysis independence. Relapse occurred in 34% after a median of 13 months and was more common in patients with WG (P = 0.048) and proteinase 3-ANCA (P = 0.034). Leukopenia occurred in 41% and was associated with sepsis (P < 0.001). CONCLUSION: Mortality and morbidity of ANCA-associated systemic vasculitis are improving compared with previous series, but remain high. Renal vasculitis often affects older patients, who have a particularly poor outcome. Early diagnosis improves outcome. Leukopenia, caused by immunosuppressive therapy, should be avoided because of the close association with sepsis and death.