Effects of Ramipril and Telmisartan on Plasma Concentrations of Low Molecular Weight and Protein Thiols and Carotid Intima Media Thickness in Patients with Chronic Kidney Disease.

Hypertension, a common feature in chronic kidney disease (CKD), is an independent risk factor for CKD progression and cardiovascular disease. Although inhibitors of the renin-angiotensin system (RAS) exert salutary effects on blood pressure control and proteinuria in CKD patients, their activity towards traditional and novel oxidative markers is largely unknown. We studied the effects of 6-month treatment with telmisartan versus a combination of telmisartan and ramipril on plasma concentrations of low molecular mass (LMW, including homocysteine and cysteine) and protein thiols (PSH) plasma concentration and their relationships with carotid intima media thickness (IMT), in 24 hypertensive CKD patients (age 60 ± 12 years, 8 females and 16 males). Pretreatment PSH concentrations were independently associated with IMT (r = -0.42, p = 0.039). Neither treatment affected plasma LMW thiols, in both reduced and total form. By contrast, both treatments increased PSH plasma concentrations and reduced IMT, although significant differences were only observed in the combined treatment group. Our results suggest that the beneficial effects of combined RAS inhibitor treatment on IMT in hypertensive CKD patients may be mediated by a reduction of oxidative stress markers, particularly PSH.

Effect of cholesterol lowering treatment on plasma markers of endothelial dysfunction in chronic kidney disease.

The elevated cardiovascular morbidity and mortality in chronic kidney disease (CKD) is linked with endothelial dysfunction secondary to the pro-inflammatory and pro-oxidative state typical of this pathology. In consideration of the well-known pleiotropic effect of statins, we investigated the effect of cholesterol lowering treatment on endothelial dysfunction markers (MED), asymmetric dimethylarginine (ADMA), vascular cell (VCAM) and intercellular (ICAM) adhesion molecule. Plasma MED concentrations, inflammation and oxidative stress indices [Kynurenine/Tryptophan (Kyn/Trp) ratio, malondialdehyde (MDA) and allantoin/uric acid (All/UA) ratio] were measured in 30 CKD patients randomized to three cholesterol lowering regimens for 12 months (simvastatin 40mg/day, ezetimibe/simvastatin 10/20mg/day, or ezetimibe/simvastatin 10/40mg/day). Treatment significantly reduced ADMA concentrations in all patients [0.694µmol/L (0.606-0.761) at baseline vs. 0.622µmol/L (0.563-0.681) after treatment, p<0.001]. ADMA reduction was paralleled by a significant decrease of MDA, All/AU ratio and Kyn/Trp ratio, but not VCAM and ICAM plasma concentrations. Cholesterol lowering treatment was associated with a significant reduction in plasma ADMA concentrations in CKD patients. This might be mediated by reduced oxidative stress and inflammation.

Renal hemodynamics and renoprotection.

BACKGROUND: Angiotensin II (AII) is the well-known determinant of kidney damage increasing intraglomerular pressure, matrix expansion and fibroblast proliferation. Renin-angiotensin system (RAS) inhibition, limiting the hemodynamic effects of AII, reduces proteinuria and is renoprotective in the long term. METHODS: We studied 15 chronic proteinuric patients by Doppler ultrasonography to clarify the intrarenal hemodynamic changes during RAS blockade by Benazepril (10-20 mg/day) alone and combined with Valsartan (80-160 mg/day). We also investigated the correlation between hemodynamic indices, RAS components and antiproteinuric effect. RESULTS: After 1 month of Benazepril proteinuria, resistive index (RI) and pulsatility index (PI) significantly decreased and proteinuria reduction was directly correlated to decrease in RI (r = 0.55, p = 0.03). Contrarily, after 1 month of combined therapy, RI and PI restored to baseline and progressively increased in the following 3 months, while proteinuria decreased. Increase in RI was directly correlated to concomitant increase in plasma renin activity (r = 0.65, p = 0.01) suggesting a direct role of renin in restoring intrarenal resistances. CONCLUSION: The hemodynamic changes caused by RAS inhibitors partially contribute to the antiproteinuric effect. Other RAS components, such as renin, may contribute to renal vasoconstriction and could be a further determinant of kidney damage besides a promising target for renoprotection.

Quali-quantitative analysis of urinary glycosaminoglycans for monitoring glomerular inflammatory activity.

OBJECTIVE: A 2-year follow-up study was carried out in patients with IgA nephropathy (IgAN) in order to verify the possible use of quali-quantitative analysis of urinary glycosaminoglycans (GAGs) as a prognostic index of disease and for drug treatment monitoring. MATERIAL AND METHODS: Ten patients with IgAN were evaluated at four time points: baseline, and 6, 9 and 24 months later. GAGs were isolated from 24-h urine using ion-exchange chromatography on diethylaminoethyl-Sephacel, and concentrations were expressed as milligrams of hexuronate per gram of creatinine. GAG composition was determined by cellulose acetate electrophoresis and expressed as relative percentages by means of densitometric scanning of Alcian Blue-stained strips. RESULTS: The relative content of total low-sulphated chondroitin sulphate species decreased significantly during the study period compared to baseline, whereas the relative percentages of heparan sulphate and chondroitin sulphate increased significantly. Moreover, a significant correlation was noted between the relative contents of urinary GAGs, renal function and inflammation indexes. CONCLUSIONS: It is likely that the excretion of various types of GAGs may be related to different glomerular pathophysiological conditions. Therefore, the determination of urinary GAG composition may represent a reliable indicator of disease activity.

A complex case of renal amyloidosis with a rare co-occurrence of 2 mutations in separate hereditary periodic fever syndrome-related genes.

A 41 year-old male was admitted because of nephrotic syndrome associated with renal impairment and arterial hypertension. Renal biopsy showed a complete subverting of renal architecture with eosinophilic, amorphous deposits which stained positive for Congo red and were positive for antibodies against AA-amyloid. Abdominal fat pad aspirate confirmed the diagnosis of AA amyloidosis. Despite high values of serum amyloid A (SAA), surprisingly medical history, physical examination and all tests failed to identify any underlying inflammatory disease, even asymptomatic, at presentation and during the whole follow-up period. The patient carried a mutation (Glu148Gln) in the MEFV gene, and a mutation (Arg92Gln) in the TNFRSF1A gene, both in heterozygosity. The patient has never complained of the typical features of the Familial Mediterranean fever or of the TNF receptor-associated periodic syndrome. The patient's father carried the same mutations. His father's medical history was unremarkable; renal tests, acute-phase reactants and SAA were normal. During a trial with colchicine (while the patient was also taking atorvastatin) SAA decreased, renal function continued to deteriorate and proteinuria remained high; no cardiac involvement was detected. Six months later our patient developed rhabdomyolysis, thus accelerating the decline of renal function and requiring the start of dialysis.

A case of adult-onset tubulointerstitial nephritis and uveitis ("TINU syndrome") associated with sacroileitis and Epstein-Barr virus infection with good spontaneous outcome.

The authors report a case of tubulointerstitial nephritis and uveitis (TINU syndrome) in a 48-year-old woman. The patient's ocular symptoms (relapsing bilateral uveitis) began 4 months before the renal disease was diagnosed and were treated successfully with local steroid therapy. The main baseline laboratory findings were anemia, a rapid sedimentation rate, and a decreased renal function. Urinalysis results showed mild proteinuria and some hyaline and hyaline-granular casts. Immunoglobulin (Ig) G and IgM antibodies to Epstein-Barr virus (EBV) were present. The renal biopsy showed interstitial lymphocytes and infiltration by rare plasma cells, tubular atrophy without granulomas, and slight expansion of the mesangium; electronic microscopy showed rare electron-dense deposits in the mesangium; no vascular alterations were seen, and immunofluorescent staining was uniformly negative. X-ray of the pelvis showed bilateral sacroileitis, which has been previously described in only 1 case of TINU syndrome; human leukocyte antigen B27 was negative. After 6 months without any therapy, all laboratory findings were normal; after 30 months, renal function was still normal, uveitis had not relapsed, but sacroiliac involvement was still present; EBV-viral capsid antigen (VCA) IgM were still high (28 UA/mL), and the EBV IgG titers were increased (VCA>170, EBV-nuclear antigen 108 UA/mL). This case confirms that this rare entity, originally observed in children, may occur and have a favorable spontaneous renal outcome also in the adult; EBV may play a role, as previously suggested. This is, to the authors' knowledge, the first reported case of TINU syndrome with the association of a well-documented bilateral sacroileitis.