Biomedical subjects

Georgios Sakellariou

Publications and source records attributed to Georgios Sakellariou.

5 recordsLinked to original sources

PubMed2006

Initial dosing of paricalcitol based on PTH levels in hemodialysis patients with secondary hyperparathyroidism.

BACKGROUND: Adjustment of the initial dose of paricalcitol in hemodialysis patients with secondary hyperparathyroidism (SHPT) on the basis of severity of SHPT generally is preferred in current practice. Whether the proposed dose, based on the formula baseline intact parathyroid hormone (iPTH [picograms per milliliter]) divided by 80, is the most appropriate has not been assessed adequately. METHODS: A double-blind randomized trial comparing iPTH/80 dose with the immediately lower iPTH/120 dose was undertaken. Forty-three hemodialysis patients with iPTH levels between 300 and 900 pg/mL (300 and 900 ng/L) were followed up for 12 weeks. The primary outcome was control of iPTH levels within a target range between 150 and 300 pg/mL (150 and 300 ng/L). RESULTS: No difference between the 2 dose groups was noted in time to achieve target iPTH levels of 150 to 300 pg/mL (150 to 300 ng/L). More episodes of excessive decrease in iPTH levels occurred in the iPTH/80 group compared with the iPTH/120 group (P = 0.003). Nine patients in the iPTH/80 group (45%) versus 2 patients in the iPTH/120 group (10%) had iPTH levels less than 150 pg/mL (<150 ng/L) in at least half the measurements performed during the second half of the study (P = 0.034). Increases in calcium levels were greater in the iPTH/80 group at all times during the study (P < 0.05 at weeks 4 and 10). The number of required dose reductions was significantly greater in the iPTH/80 group compared with the iPTH/120 group (P = 0.008). CONCLUSION: In hemodialysis patients with SHPT, a lower initial dose of iPTH/120 shows efficacy similar to that of the already widely used iPTH/80 scheme in reaching target iPTH levels (150 to 300 pg/mL [150 to 300 ng/L]), with less required dose adjustments, lower increase in calcium levels, and lower cost. In addition, the initial dose of paricalcitol based on the iPTH/80 formula leads significantly more patients to excessive suppression of iPTH (<150 pg/mL [<150 ng/L]) than the iPTH/120 dose.

Aged↗

PubMed2005

Increase in serum magnesium level in haemodialysis patients receiving sevelamer hydrochloride.

BACKGROUND: Clinical studies have shown that sevelamer hydrochloride improves lipid profiles and attenuates the progression of the cardiovascular calcifications in haemodialysis patients. It is known that both of these properties are associated with increased magnesium levels. The effect of sevelamer on serum magnesium level is not well documented. The aim of this study was to determine the effects of sevelamer treatment on serum magnesium in haemodialysis patients and to assess the association of magnesium levels with lipid profiles and intact parathyroid hormone (iPTH). METHODS: Phosphate binders were discontinued during a two week washout period. Forty-seven patients, whose serum phosphate was greater than 6.0 mg/dl at the end of washout, received sevelamer hydrochloride for eight weeks. The patients were then washed off sevelamer for another two weeks. RESULTS: Mean serum phosphorus concentration declined from 7.5 +/- 1.3 to 6.4 +/- 1.2 mg/dl (P < 0.001), mean serum magnesium levels increased from 2.75 +/- 0.35 to 2.90 +/- 0.41 mg/dl (P < 0.001) and median serum iPTH levels decreased from 297 to 213 pg/ml (P=0.001) during the eight weeks of sevelamer treatment. After the two week post-treatment washout phosphorus levels increased to 7.3 +/- 1.3 mg/dl (P < 0.001), magnesium levels were reduced to 2.77 +/- 0.39 mg/dl (P < 0.001) and iPTH levels increased to 240 pg/ml (P=0.012). No change was observed in serum calcium levels during the sevelamer treatment period and the subsequent washout period. The mean decline in total and low density lipoprotein (LDL) cholesterol during sevelamer treatment was 16.3 and 28.3 (P < 0.001), respectively. The mean increase in high density lipoprotein (HDL) cholesterol and in apolipoprotein A1 was 2.9 +/- 5.8 mg/dl (P=0.004) and 6.8 +/- 11.1 mg/dl (P=0.001), respectively. Multivariate analysis showed that the rise in serum magnesium concentration significantly correlated with reductions in iPTH levels (r=-0.40, P=0.016), but did not have any significant correlation with the changes in lipid profiles. CONCLUSIONS: Our findings indicate that patients on haemodialysis receiving sevelamer have a significant increase in serum magnesium concentrations. This increase in serum magnesium is associated with reduction in iPTH levels. The changes in lipid profiles of these patients however are not related to changes in serum magnesium levels.

Female↗

PubMed2005

Human serum facilitates hepatitis C virus infection, and neutralizing responses inversely correlate with viral replication kinetics at the acute phase of hepatitis C virus infection.

The factors leading to spontaneous clearance of hepatitis C virus (HCV) or to viral persistence are elusive. Understanding virus-host interactions that enable acute HCV clearance is key to the development of more effective therapeutic and prophylactic strategies. Here, using a sensitive neutralization assay based on infectious HCV pseudoparticles (HCVpp), we have studied the kinetics of humoral responses in a cohort of acute-phase patients infected during a single nosocomial outbreak in a hemodialysis center. The 17 patients were monitored for the spontaneous outcome of HCV infection for 6 months before a treatment decision was made. Blood samples were taken frequently (15 +/- 4 per patient). Phylogenetic analysis of the predominant virus(es) revealed infection by only one of two genotype 1b strains. While all patients seroconverted, their sera induced two opposing effects in HCVpp infection assays: inhibition and facilitation. Furthermore, the ability of sera to facilitate or inhibit infection correlated with the presence of either infecting HCV strain and divided the patients into two groups. In group 1, the progressive emergence of a relatively strong neutralizing response correlated with a fluctuating decrease in high initial viremia, leading to control of viral replication. Patients in group 2 failed to reduce viremia within the acute phase, and no neutralizing responses were detected despite seroconversion. Strikingly, sera of group 2, as well as naive sera, facilitated infection by HCVpp displaying HCV glycoproteins from different genotypes and strains, including those retrieved from patients. These results provide new insights into the mechanisms of viral persistence and immune control of viremia.

Acute Disease↗

PubMed2004

Immunoadsorption in lupus myocarditis.

Reduction of pathological autoantibodies may be useful in the treatment of systemic lupus erythematosus (SLE). On the other hand clinically manifested myocarditis in SLE, though uncommon, may be life-threatening and its pathogenesis has been ascribed to autoimmunity. The aim of this study is to present a rare case of a patient with severe lupus myocarditis, where immunoadsorption (IA) was evaluated as rescue therapy. A case of SLE with initial manifestation of myocarditis is reported in a 29-year-old male who presented with arthritis, fever, lymphadenopathy, joint swelling and morning stiffness. Laboratory evaluation revealed increased antinuclear antibody (ANA), slightly decreased complement and positive anticoagulant panel. From the above clinical and laboratory features, criteria of SLE seemed applicable. During his hospitalization, the patient developed pericardial effusion and cardiogenic shock. Although pericardiotomy was performed and was treated with immunosuppressive agents, plasmapheresis and supported with current medications, his clinical condition remained critical with an ejection fraction of 20%. At this point it was decided to receive IA onto staphylococcal protein A. After 6 sessions with IA and concomitant immunosuppression, the patient responded well, his condition improved and was dismissed with an ejection fraction of 50%. Fulminant lupus myocarditis is a severe and rare situation lacking a satisfying specific therapy available today. In our presented case, IA in addition to immunosuppressive therapy was beneficial. Considering the benefits of our case and the current knowledge, it might be useful to clarify the open question in scale pilot studies.

Adult↗

PubMedDate not supplied

Do serum and red blood cell folate levels indicate iron response in hemodialysis patients?

The relationship among iron status, ferritin, and folate levels, and the possible contribution of folate measurement in the prediction of iron response in hemodialysis patients, have not been assessed. In addition to serum ferritin and transferrin saturation (TSAT), serum and red blood cell (RBC) folate levels were evaluated as indices for intravenous iron therapy responsiveness in 60 hemodialysis patients. Patients were classified as iron responders or nonresponders depending on whether they exhibited a rise in hemoglobin above 1 g/dl after administration of 1 g of iron sucrose. An inverse relation between serum ferritin concentration and RBC folate levels was found in iron responders (n=26, r=-0.62, p<0.001) but not in nonresponders (n=34, r=0.07, p=nonsignificant). Only serum and RBC folate levels could predict iron response in patients with ferritin levels above 150 microg/l (n=25), with a sensitivity of 83.3% and a specificity of 94.7%. Our findings suggest that RBC folate concentration is inversely related with ferritin levels in iron-responsive but not in non-responsive hemodialysis patients. Serum and RBC folate concentration seems to predict response to iron administration better than serum ferritin or TSAT in patients with ferritin levels above 150 microg/l; therefore, in these patients, it might be used to guide iron management.

Anemia, Iron-Deficiency↗