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Query: UNIPROT:P02794 (ferritin)
 17,525 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A prospective study was planned to follow the clinical and laboratory data of hemodialysis (HD) patients after change of treatment to continuous ambulatory peritoneal dialysis (CAPD). Patients who had been on the HD program for more than 6 months were selected and followed for at least 6 months under CAPD treatment. Measured parameters included hemoglobin, ferritin, C-reactive protein (CRP), calcium, phosphorus, and intact parathyroid hormone (iPTH) levels; lipid profile; total protein and albumin; body mass index and triceps skin fold thickness; echocardiographic findings; and medications administered. We followed 34 patients (12 males, 22 females; mean age: 43.5 +/- 14.5 years; mean HD duration: 36.6 +/- 24.76 months) for a mean period of 19.8 +/- 11.9 months after change of treatment to CAPD. We saw a significant increase in mean hemoglobin, cholesterol, triglyceride, high-density lipoprotein (HDL), lipoprotein (a) [Lp(a)], phosphorus, and iPTH levels. We observed a decrease in erythropoietin dose, mean ferritin levels, systolic blood pressure (139.4 +/- 22.8 mmHg vs 114.4 +/- 21.0 mmHg, p = 0.001), diastolic blood pressure (85.7 +/- 12.6 mmHg vs 73.5 +/- 17.6 mmHg, p = 0.002), percentage of left ventricular hypertrophy, systolic and diastolic dysfunction, and the number of hypertensive drugs received. A significant improvement in the nutritional status of the patients (total protein, body mass index and triceps skin fold thickness) was also seen. In conclusion, CAPD treatment has a short-term outcome superior to that of HD in terms of better nutritional status and better control of hypertension and anemia.
Adv Perit Dial 2000
PMID:What happens after conversion of treatment to continuous ambulatory peritoneal dialysis from hemodialysis? 1104 88

Adynamic bone disease (ABD) has an increasing prevalence in the dialysis population, more so in peritoneal dialysis patients. Anemia in patients with high turnover bone disease and high intact parathyroid hormone (iPTH) tends to be resistant to recombinant human erythropoietin (rHuEPO). The same problem may occur in patients with ABD; however, data are scarce. This study evaluates the effectiveness of rHuEPO in 32 chronic peritoneal dialysis patients, 9 with iPTH levels below 100 pg/mL for more than 6 months (group A, with ABD) and 23 with iPTH levels above 100 pg/mL (group B, without ABD). In group A and group B respectively, the dosage of rHuEPO was 141.8 +/- 59 U/kg/week and 144.8 +/- 77 U/kg/week, and hematocrit was 33.2% +/- 4.3% and 31.7% +/- 4.5% (p > 0.05). Iron indices, nutritional parameters, and bone indices were similar, except that group A had lower alkaline phosphatase and serum ferritin levels. The data suggest that patients with ABD may not be resistant to rHuEPO, but may even have a slightly better hematocrit at a similar rHuEPO dosage. Further studies in a larger number of patients are needed to confirm these findings.
Adv Perit Dial 2000
PMID:Influence of adynamic bone disease on responsiveness to recombinant human erythropoietin in peritoneal dialysis patients. 1104 14

The invention of recombinant human erythropoietin (rHuEpo) for the treatment of renal anaemia was a hallmark in the care of patients with renal insufficiency. Recently published guidelines (European Best Practice Guidelines, NKF-DOQI) have set the target haemoglobin to be reached by treatment with rHuEpo to >11 g/dl. Normalizing haemoglobin levels may reduce morbidity and mortality and improve quality of life in haemodialysis patients. During long-term treatment, most patients will not respond adequately to therapy with rHuEpo alone. The most important confounding factor, limiting the effectiveness of rHuEpo, is absolute or functional iron deficiency, which is now recognized and treated in many dialysis units. However, there are several other adjuvant treatment options which may help to optimize the response to treatment with rHuEpo. A weekly dose of 2-3 mg of folic acid and 100-150 mg of vitamin B6 is recommended for haemodialysis patients on rHuEpo therapy. The addition of 0.25 mg/month of vitamin B12 may be necessary in selected patients. Vitamin C (1-1.5 g/week) was shown to overcome functional iron deficiency in patients with high ferritin levels. The potential increase of oxidative stress induced by intravenous iron therapy may be blunted by concomitant administration of vitamin E (1200 IU). There is clear evidence from the literature that treatment of secondary hyperparathyroidism by vitamin D improves erythropoiesis. The most recently discovered biological effects of rHuEpo include the induction of several genes in endothelial cells as well as a role for erythropoietin in the outcome of plasmodium infection. A new erythropoietin-like molecule is novel erythropoiesis stimulating protein (NESP), which is as effective and safe as rHuEpo, with the potential advantage of less frequent dosing.
Nephrol Dial Transplant 2001
PMID:Novel aspects of erythropoietin response in renal failure patients. 1150 83

The aim of the present study was to examine the association between 4-hour dialysate-to-plasma ratio of creatinine (D/PCr), erythropoietin (EPO) responsiveness [EPO (U/week)/hemoglobin (g/L)], and C-reactive protein (CRP). Subjects were 54 prevalent peritoneal dialysis (PD) patients [mean age: 58 years; 30 women, 24 men; 28 with diabetes; 15 on continuous ambulatory peritoneal dialysis (CAPD); 39 on continuous cycling peritoneal dialysis (CCPD); mean Kt/V: 2.44]. In 17 patients, CRP was elevated (> 15 mg/L), and in 39 patients, 4-hour D/PCr was high or high-average (> or = 0.65). Mean hemoglobin (Hb) was 115.5 +/- 12.9 g/L; median EPO dose was 2800 U/week, and median EPO/Hb was 24.5. A nonsignificant negative correlation was noted between CRP and hemoglobin (r = -0.25, p = 0.07), but no correlations were seen between CRP and 4-hour D/PCr, or hemoglobin and 4-hour D/PCr. No correlation was seen between EPO/Hb and 4-hour D/PCr or CRP. Multiple linear regression (stepwise, alpha = 0.05) was performed with outcome hemoglobin and independent variables EPO [U/week (forced in)], percent transferrin saturation [TSAT (forced in)], age, sex, diabetes mellitus, serum albumin, CRP, time on PD, 4-hour D/PCr, normalized protein catabolic rate (nPCR), ferritin, intact parathyroid hormone (iPTH), aluminum, and angiotensin converting enzyme inhibitor (ACEI) use. Serum albumin (1.27, p < 0.01) and diabetes mellitus (-6.69, p = 0.04) were the only significant predictors of hemoglobin. With serum albumin removed from the model, age (but not CRP) became significant. These results do not support an association between peritoneal transport and EPO responsiveness, mediated by inflammation. The association between serum albumin and hemoglobin appears to be confounded by age more than by inflammation.
Adv Perit Dial 2001
PMID:Inflammation, peritoneal transport, and response to erythropoietin in peritoneal dialysis patients. 1151 Feb 66

Our aim was to show, in continuous ambulatory peritoneal dialysis (CAPD) patients, the relationships between zinc (serum level and dietary intake) and adequacy and duration of CAPD, age, and measures of nutrition. Serum zinc (12.2 +/- 1.8 mumol/L) was not significantly related to dietary zinc intake (9.9 +/- 2.5 mg daily), but depended on daily instilled (r = -0.331, p < 0.05) and effluent (r = -0.311, p < 0.05) dialysate volumes and on patient age (r = -0.304, p < 0.05). Positive correlations were seen between serum zinc level and laboratory (but not anthropometric) markers of nutrition: prealbumin (r = 0.349, p < 0.05), iron (r = 0.447, p < 0.05), transferrin saturation [(TSAT) r = 0.374, p < 0.05]. Additionally, zinc intake was positively related to serum ferritin level (r = 0.370, p < 0.05). Serum zinc level positively influenced blood morphology [correlation with hemoglobin (r = 0.287, p < 0.05) and mean corpuscular hemoglobin concentration (r = 0.361, p < 0.05)]. Zinc intake showed negative correlations with serum levels of total cholesterol (r = -0.373, p < 0.05) and vitamin E (r = -0.504, p < 0.05), and a positive correlation with HDL: total cholesterol ratio (r = 0.338, p < 0.05). Mean values of three latter parameters were out of the normal limits (total cholesterol: 219.2 +/- 47.0 mg/dL; vitamin E: 1.91 +/- 0.82 mg/dL; HDL: total cholesterol ratio: 16.7 +/- 5.1). We conclude that, in CAPD patients, zinc is a marker of nutrition showing beneficial effect on serum iron parameters, blood morphology, lipid profile, and elevated vitamin E concentration. Zinc supplementation is needed for approximately 16% of CAPD patients, especially older patients and those requiring higher dialysate volumes.
Adv Perit Dial 2001
PMID:Zinc as a marker of nutrition in continuous ambulatory peritoneal dialysis patients. 1151 Feb 81

The present study looked for variations in blood morphology between diabetic patients (group I, n = 7) and non diabetic patients (group II, n = 16) treated with continuous ambulatory peritoneal dialysis (CAPD). A subsequent trial sought to find a reason for discrepancies in the results between the two groups. The patients in both groups and similar ages, CAPD durations, and erythropoietin dosages. Nutrition, CAPD adequacy, serum iron and ferritin levels, total iron binding capacity (TIBC), transferrin saturation (TSAT), red blood cells (RBCs), mean corpuscular hemoglobin (MCH), mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), hemoglobin (Hb), hematocrit (Hct), white blood cells (WBCs), total lymphocyte count (TLC), platelets (PLTs), and serum intact parathyroid hormone (PTH) were evaluated every three months. The mean result of each parameter was obtained in every patient as representative for the entire CAPD course. Means and standard deviations for all respective parameters were then calculated for the two groups and compared. In patients with diabetes as compared with patients without diabetes, significantly higher numbers of RBCs, WBCs, and PLTs were seen, as were higher values for Hb and Hct and a lower serum PTH concentration. Values for WBCs, PLTs, and MCH obtained in all patients (n = 23) were correlated with serum intact PTH (r = -0.520, p = 0.011; r = -0.422, p = 0.045; and r = -0.436, p = 0.037 respectively). When data obtained in the patients receiving erythropoietin were excluded and the correlation analysis was repeated for the 10 remaining patients, a correlation between serum PTH and RBCs was found (r = -0.685, p = 0.029). With comparable age, renal function, nutrition, erythropoietin dosage, iron indices, and CAPD adequacy, duration, and outcome, higher parameters of blood morphology in diabetic patients may be related to lower levels of serum intact PTH, indicating no or only mild secondary hyperparathyroidism. Patients with diabetes usually show smaller disturbances in PTH level than do non diabetic uremic patients on CAPD. Better peripheral morphology indices in the group with diabetes can be expected when other factors affecting hematologic status are similar.
Adv Perit Dial 2001
PMID:Parathyroid hormone contributes to variations in blood morphology in diabetic and non diabetic patients treated with continuous ambulatory peritoneal dialysis. 1151 Feb 96

Patients with end-stage renal disease (ESRD) are at a markedly increased risk for cardiovascular complications compared with the general population. In addition to traditional cardiovascular risk factors such as diabetes mellitus, hypertension, hyperlipidaemia or cigarette smoking, a number of population-specific factors are implicated, such as anaemia, hyperhomocysteinaemia, hyperphosphataemia and vascular calcification, as well as inflammation and oxidative stress. Iron overload has been suggested to increase the cardiovascular risk in the general population. Iron supplementation is a widespread clinical practice in ESRD, especially in patients on maintenance haemodialysis (HD). Iron may therefore contribute to cardiovascular complications through effects on low-density lipoprotein oxidation and endothelial dysfunction. Although the effects of iron stores and iron therapy on cardiovascular risk are not well defined in HD patients, the 'iron hypothesis' deserves attention: serum ferritin is a marker of morbidity and mortality in HD patients, and the administration of high amounts of intravenous iron increases the risks of hospitalization and death. In contrast to intravenous iron therapy, intestinal iron absorption is regulated by body iron stores and is suppressed in the presence of infection and iron overload. Prospective studies are needed to clarify the influence of iron stores and iron therapy on overall and cardiovascular morbidity and mortality in ESRD patients.
Nephrol Dial Transplant 2002
PMID:Iron overload and cardiovascular complications in dialysis patients. 1190 55

An increasing number of reports documenting resistance to human recombinant erythropoietin (rHuEPO) therapy are challenging the concept that erythropoietin deficiency is the main cause of the anaemia of chronic kidney disease (CKD). In an attempt to establish whether other factors play a more predominant role in the anaemia of CKD, 988 patients receiving dialysis were assessed for a wide range of variables. Data were collected on haematocrit (Hct) levels, rHuEPO dose, dry weight, serum ferritin, transferrin saturation, serum albumin, serum aluminium, serum parathyroid hormone intact, eKt/V for urea, gender, dose of i.v. iron administered, time in hospital, and use of i.v. vancomycin. Hyporesponsiveness to rHuEPO was defined as patients requiring >500 IU/kg/week or failing to achieve Hct levels of >30%. Ninety-two (9.2%) of the 988 patients met the above criteria for hyporesponsiveness to rHuEPO. In 21 of these patients, Hct concentrations remained <30% at 6-month follow-up. There were known haematological causes of refractoriness to rHuEPO in nine of these patients. During extended follow-up, probable causes of hyporesponsiveness were discovered in all but two of the remaining 13 patients. Of 62 dialysis patients who received rHuEPO at doses >500 IU/kg/week, 45 (73%) had Hct concentrations of 33-42%. These patients were responding to the higher doses of rHuEPO with no obvious adverse effects. Lower values of serum ferritin, transferrin saturation, and eKt/V, or higher levels of parathyroid hormone or serum aluminium were not associated with higher rHuEPO dose requirements. These results suggest that erythropoietin deficiency is still the main cause of the anaemia of CKD. Erythropoietin replacement therapy can correct the anaemia in almost all iron replete patients providing enough hormone is given, functional iron deficiency is avoided, aluminium levels and parathyroid toxicities are controlled and that no de novo haematological condition that affects erythropoiesis or red blood cell survival develops. Consideration should be given to modifying the definition of rHuEPO hyporesponsiveness. The US Hct target of 33-36% for haemodialysis patients is narrow and the European target of Hct >33% may be significantly more practical and physiologically relevant.
Nephrol Dial Transplant 2002
PMID:Is it time for a paradigm shift? Is erythropoietin deficiency still the main cause of renal anaemia? 1209 99

Our knowledge of erythropoiesis and iron in renal disease is limited. The accepted view of the control of erythropoiesis was founded on observations made in a variety of disorders, but the control mechanism in healthy individuals may not be quite the same. Evidence suggests that mechanisms other than erythropoietic stimulation may play a role in increased red blood cell production. Measuring erythropoiesis is complex. The quantitative reticulocyte count is probably the closest practical assessment of erythropoietic activity we can achieve, yet there is very little correlation between circulating erythropoietin level and reticulocyte count in normal and near normal subjects. Oxygen transport in humans depends entirely upon iron. In renal disease, the failure of the erythropoietin positive feedback mechanism can be readily and directly remedied; recombinant human erythropoietin therapy can replace the missing erythropoietin, but this will be negated if iron supply to the erythroid marrow falls short of demand. Measurement of iron stores is also complex. The use of serum ferritin concentration as a direct quantitative estimate of iron in the stores is not advisable, and in practice we have not found the transferrin receptor assay to be useful in identifying patients who require iron therapy. Use of percentage hypochromia as a measure of iron deficiency is complicated by the fact that hypochromic cells are not exclusively a consequence of functional iron deficiency. There are clearly lessons still to be learned in this field and there is much that we do not yet understand about the control of erythropoiesis and iron metabolism in humans.
Nephrol Dial Transplant 2002
PMID:Iron and erythropoietin in renal disease. 1209 2

Iron-derived reactive oxygen species (ROS) are implicated in the pathogenesis of numerous vascular disorders including atherosclerosis, microangiopathic haemolytic anaemia, vasculitis and reperfusion injury. One abundant source of redox-active iron is haem, which is inherently dangerous when released from intracellular haem proteins. The present review concerns the likely involvement of haem in vascular endothelial cell damage and the strategies used by endothelium to minimize such damage. Exposure of endothelial cells to haem greatly potentiates cell killing mediated by polymorphonuclear leukocytes and other sources of ROS. Free haem also promotes the conversion of low-density lipoprotein to cytotoxic oxidized products. If only because of its abundance, haemoglobin probably represents the most important potential source of haem within the vascular endothelium; free haemoglobin in plasma, when oxidized, can transfer haem to endothelium, thereby enhancing cellular susceptibility to oxidant-mediated injury. As a defence against such toxicity, upon exposure to free haem, endothelial cells up-regulate haem oxygenase-1 and ferritin. Haem oxygenase is a haem-degrading enzyme that opens the porphyrin ring, producing biliverdin, carbon monoxide and a most dangerous product-free redox-active iron. The latter can be controlled effectively by sequestration within ferritin, a multimeric protein with a very high capacity for storing iron. These homeostatic adjustments have been shown to be effective in the protection of endothelium against the damaging effects of exogenous haem and oxidants. The central importance of this protective system was highlighted recently by the discovery of a child diagnosed with haem oxygenase-1 deficiency, who exhibited extensive endothelial damage.
Nephrol Dial Transplant 2003 Jul
PMID:Haem, haem oxygenase and ferritin in vascular endothelial cell injury. 1281 58


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