NUTRITIONAL OR ACTIVE VITAMIN D FOR THE CORRECTION OF MINERAL METABOLISM ABNORMALITIES IN NON-DIALYSIS CHRONIC KIDNEY DISEASE PATIENTS?

CONTEXT: Benefits of vitamin D therapies in chronic kidney disease (CKD) are debated. OBJECTIVE: To compare the effects of medium-term native (VitD) and active (VDRA) vitamin D on parameters of mineral metabolism and arterial function in non-dialysis CKD. DESIGN: Open-label, active comparator, randomized study. SUBJECTS AND METHODS: Forty-eight adult patients, vitamin D naïve, CKD stage 3 to 5 with increased parathyroid hormone (iPTH) were randomized to receive either oral cholecalciferol 1000UI/day (n=24) or paricalcitol 1mcg/day (n=24) for 6 months. Median changes at end of study vs. baseline in serum calcidiol, iPTH, total alkaline phosphatase (ALP), and cardio-ankle vascular index (CAVI) were the efficacy parameters. RESULTS: Higher increase in calcidiol (15.5 [95%CI 13.3; 17.2] vs. 0.4 [95%CI -6.1; 3.7]ng/mL, p<0.001) were found in VitD group. Conversely, the decline of iPTH (-35.2 [95%CI -83; 9] vs. 13.3 [95%CI -8.1; 35]pg/mL, p=0.008) and ALP (-34 [95%CI -58; -11] vs. -10 [95%CI -23; -2]U/L, p=0.02) were greater after paricalcitol. More subjects experienced iPTH decrease in VDRA group (71% vs. 39%, p=0.03). The variation in CAVI and the incidence of hypercalcemia and hyperphosphatemia were similar. CONCLUSIONS: It seems that secondary hyperparathyroidism was more efficiently treated by VDRA, whereas cholecalciferol better corrected the calcidiol deficiency in non-dialysis CKD.

THE PREVALENCE OF BIOCHEMICAL ABNORMALITIES OF CHRONIC KIDNEY DISEASE. MINERAL AND BONE DISORDERS IN UNTREATED NON-DIALYSIS PATIENTS - A MULTICENTER STUDY.

BACKGROUND: There are scarce data about prevalence of mineral metabolism (MM) disorders in Romanian predialysis patients, so we assessed their occurrence and relationships in mild to severe chronic kidney disease (CKD). METHODS: One hundred fifteen non-dialysis CKD (eGFR 31, 95% CI 29-35mL/min) and 33 matched non-CKD subjects entered this multicentric, cross-sectional study. Serum 25-hydroxyvitamin D (25OHD), intact parathyroid hormone (iPTH), phosphate (PO4), total calcium (tCa) and alkaline phosphatase (AP) were measured, along with demographic and past medical history data. RESULTS: Hypovitaminosis D was equally prevalent in Controls and CKD (91% vs. 96% had 25OHD<30ng/mL). Increasing proportions of hyperparathyroidism (33% - stage 2 to 100% - stage 5; p<0.001) and hyperphosphatemia (2% - stage 3 to 38% - stage 5; p<0.001) were found. Hypocalcemia was more prevalent in stage 5 (25% vs. 6% in stage 4, none in stage 3 and Controls, p<0.001). Mineral metabolism parameters correlated with eGFR. In addition, iPTH was directly associated with PO4, AP, and urinary albumin-to-creatinine ratio (ACR), but inversely with tCa and 25OHD, while negative correlation of 25OHD with age, AP, ACR, and C-reactive protein emerged. In multiple regression, eGFR was the only predictor of iPTH (Beta -0.68, 95%CI -1.35 to -0.90, R2 0.46, p<0.001), whereas age and ACR were the determinants of 25OHD (a model which explained 14% of its variation). CONCLUSIONS: Hypovitaminosis D was very common irrespective of CKD presence and severity, and it seems worsened by older age and higher albuminuria. Hyperparathyroidism preceded hyperphosphatemia and hypocalcemia, and it seems mostly dependent on kidney function decline.

Venous versus arterial iron administration in haemodialysis. Influence on erythrocytes antioxidant parameters.

Introduction Intravenous iron administration in patients treated by haemodialysis for end stage renal disease can exacerbate oxidative stress by increasing the level of free redox active iron. A way to reduce the impact of iron on oxidative stress in haemodialysis patients may be the administration of iron through arterial extracorporeal circuit. Objective The aim of our study was to compare the influence of iron route of administration (venous versus arterial extracorporeal circuit infusion) on antioxidant parameters in red blood cells of haemodialysis patients in order to clarify if arterial iron administration can have positive impacts related to iron induced oxidative stress. Method Twenty stable patients on regular haemodialysis treatment were selected for the study. They were investigated in a cross-over design at 3 mid-week HD sessions, one week apart, without iron [HD basal] and with either IV infusion of 100mg iron sucrose over the first 20 minutes of HD session, via venous line [HDvenous], or the same solution infused on the arterial extracorporeal circulation [HDarterial]. Blood samples were drawn at 0 min, 40 min and 270 min. Erythrocytes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) activity, non-protein thiol levels and total antioxidant capacity (TEAC) were analysed. Conclusion Haemodialysis significantly decreases the total antioxidant activity in erythrocytes. Iron supplementation, through venous or arterial extracorporeal route has no impact on the total antioxidant activity in red blood cells. Venous iron administration increases GPx activity in erythrocytes suggesting increased lipid peroxidation compared with arterial extracorporeal administration.

Prevalence of virulence genes in Escherichia coli strains isolated from Romanian adult urinary tract infection cases.

A total of 78 E. coli strains isolated from adults with different types of urinary tract infections were screened by polymerase chain reaction for prevalence of genetic regions coding for virulence factors. The targeted genetic determinants were those coding for type 1 fimbriae (fimH), pili associated with pyelonephritis (pap), S and F1C fimbriae (sfa and foc), afimbrial adhesins (afa), hemolysin (hly), cytotoxic necrotizing factor (cnf), aerobactin (aer). Among the studied strains, the prevalence of genes coding for fimbrial adhesive systems was 86%, 36%, and 23% for fimH, pap, and sfa/foc,respectively. The operons coding for Afa afimbrial adhesins were identified in 14% of strains. The hly and cnf genes coding for toxins were amplified in 23% and 13% of strains, respectively. A prevalence of 54% was found for the aer gene. The various combinations of detected genes were designated as virulence patterns. The strains isolated from the hospitalized patients displayed a greater number of virulence genes and a diversity of gene associations compared to the strains isolated from the ambulatory subjects. A rapid assessment of the bacterial pathogenicity characteristics may contribute to a better medical approach of the patients with urinary tract infections.