Effect of the direct renin Inhibitor aliskiren in the prevention of experimental contrast-induced nephropathy in the rat

Background: Renal vasoconstriction, activated by the reninangiotensin system, plays a pivotal role in the pathogenesis of contrast-induced nephropathy (CIN). The purpose of this study was to evaluate the effect of aliskiren, a direct renin inhibitor, for the prophylaxis of experimental CIN in the rat. Methods: Thirty-two Wistar albino rats were divided into four groups of 8 rats each, namely the control (C), aliskiren (A), contrast media (CM) and aliskiren plus contrast media (ACM) groups. Aliskiren was given orally at a dose of 50 mg/kg/day once daily for 5 consecutive days. CIN was induced by intravenous administration of indomethacin, N-nitro-L-arginine methyl ester and high-osmolar contrast medium meglumine amidotrizoate. Renal function parameters, kidney histology and tubular expression of vascular endothelial growth factor were determined. Results: Mean serum creatinine was significantly lower (p < 0.001) and mean creatinine clearance was higher (p < 0.001) in the ACM group compared with the CM group. However, there were no differences between the ACM and CM groups in terms of tubular necrosis, proteinaceous casts, medullary congestion and vascular endothelial growth factor expression. Conclusion: Our preliminary data seem to suggest a potential role of aliskiren for the prophylaxis of CIN in an experimental rat model.Department of Nephrology, Marmara University School of Medicine, Istanbul, Turke

Niveles de vitamina D en pacientes con vasculitis de pequeños y vasos medianos

Objectives: To determine the prevalence of vitamin D deficiency in patients with small and medium vessel systemic vasculitis.& nbsp;Methods: In this cross-sectional study, 25-hydroxy (OH) vitamin D3 levels were measured in adult patients with systemic small and medium vessel vasculitis including antineutrophil cytoplasmic antibody-associated vasculitis (AAV), cryoglobulinaemic vasculitis (CryV), IgA vasculitis (IgAV) and pol-yarteritis nodosa (PAN), and age- and sex-matched healthy subjects (HS) and patients with rheumatoid arthritis (RA) as control groups. 25OH vitamin D3 levels < 30 ng/ml and < 20 ng/ml were regarded as insufficiency and deficiency, respectively.& nbsp;Results: Fifty-seven patients (42 AAV, 2 CryV, 8 IgA vasculitis, 5 PAN) with systemic vasculitis, 101 HS, and 111 RA patients were included. The mean 25OH vitamin D3 level was 21.8 +/- 14.2 ng/mL in patients with vasculitis, 42.7 & nbsp;+/- 27.6 ng/mL in HS (p < .001) and 20.1 +/- 18.47 ng/mL in patients with RA (p = .54). Vitamin D insufficiency and deficiency were significantly higher in patients with systemic vasculitis compared to HS (75.4% vs 33.7%, p < .001; %50 vs 21.8%, p < .001, respectively). Vitamin D status was not different in patients with systemic vasculitis compared to RA. There was a negative correlation between vitamin D status and CRP levels (=-.364, p = .007). The multivariate logistic regression analysis showed that renal involvement was significantly associated with vitamin D deficiency/insufficiency in patients with vasculitis (OR 22.5 [95% CI 1.6-128.9].& nbsp;Conclusion: Vitamin D deficiency and insufficiency are more frequent in patients with systemic small and medium vessel vasculitis and RA than HS. Renal involvement is one of the factors associated with vitamin D deficiency/insufficiency in patients with vasculitis.Objetivos: Determinar la prevalencia de la deficiencia de vitamina D en los pacientes con vasculitis sistémica de peque ̃nos y medianos vasos. Métodos: En este estudio transversal se midieron los niveles de 25-hidroxivitamina D3 en pacientes adul- tos con vasculitis sistémica de peque ̃nos y medianos vasos, incluyendo vasculitis asociada a anticuerpos anticitoplasma de neutrófilos (AAV), vasculitis crioglobulinémica (CryV), vasculitis IgA (IgAV) y poliar- teritis nodosa (PAN), y sujetos sanos pareados por edad y sexo (SS) y pacientes con artritis reumatoide (AR) como grupos control. Se consideraron insuficientes y deficientes los niveles de 25-hidroxivitamina D3 < 30 ng/ml y < 20 ng/ml, respectivamente. Resultados: Se incluyeron 57 pacientes (42 de AAV, 2 de CryV, 8 de vasculitis IgA y 5 de PAN) con vasculitis sistémica, 101 SS y 111 pacientes de AR. El nivel medio de 25-hidroxivitamina D3 fue de 21,8 ± 14,2 ng/ml en pacientes con vasculitis, 42,7 ± 27,6 ng/ml en SS (p < 0,001) y 20,1 ± 18,47 ng/ml en pacientes con AR (p = 0,54). La insuficiencia y deficiencia de vitamina D fueron significativamente más altas en los pacientes con vasculitis sistémica en comparación con los SS (75,4 vs. 33,7%; p < 0,001; 50 vs. 21,8%; p < 0,001, respectivamente). El estatus de vitamina D no fue diferente en los pacientes con vasculitis sistémica en comparación con AR. Existió una correlación negativa entre el estatus de vitamina D y los niveles de PCR = −0,364; p = 0,007. El análisis de regresión logística multivariante reflejó que el compromiso renal estuvo significativamente asociado a la deficiencia/insuficiencia de vitamina D en los pacientes con vasculitis (OR: 22,5; IC 95%: 1,6-128,9). Conclusión: La insuficiencia y deficiencia de vitamina D son más frecuentes en los pacientes con vasculitis sistémica de peque ̃nos y medianos vasos y AR que en los SS. El compromiso renal es uno de los factores asociados a la deficiencia/insuficiencia de vitamina D en los pacientes con vasculitis

Prediction of subclinical left ventricular dysfunction by speckle-tracking echocardiography in patients with anti-neutrophil cytoplasmic antibody--associated vasculitis

Objectives: This study aims to evaluate left ventricular functions using speckle-tracking echocardiography (STE) in patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). Patients and methods: Between June 2018 and July 2019, a total of 31 AAV patients (17 males, 14 females; median age: 53 years; range, 47 to 62 years) and 21 healthy controls (11 males, 10 females; median age: 56 years; range, 46 to 60 years) were included in the study. Clinical and biochemical characteristics of all participants were recorded. All participants underwent conventional and two-dimensional STE. The receiver operating characteristic (ROC) curve analysis was performed to determine the cut-off value of serum N-terminal prohormone of brain natriuretic peptide (NT-pro-BNP) that predicted subclinical left ventricular dysfunction. The Spearman correlation analysis was used to determine the correlation between left ventricular global longitudinal strain (LV-GLS) and NT-pro-BNP. Results: The LV-GLS was lower in AAV patients (19.3% vs. 21.7%, respectively; p=0.014). NT-pro-BNP was negatively correlated with LV-GLS (p=0.005, r=0.401). Conclusion: Subclinical left ventricular dysfunction can be detected by STE in patients with AAV who have free of clinically overt cardiovascular disease. The LV-GLS is negatively correlated with serum NT-pro-BNP levels