Anemia in chronic kidney disease and congestive heart failure

Research on the relationship between serum indoxyl sulfate concentration and iron dynamics index in patients with end-stage kidney disease: a cross-sectional study

Background

Chronic kidney disease (CKD) is frequently associated with renal anemia. Erythropoiesis-stimulating agent-hyporesponsive anemia is often caused by iron deficiency in patients with CKD. We hypothesized that high accumulation of indoxyl sulfate, a uremic toxin, accelerates iron deficiency in patients with CKD. The aim of this study was to clarify whether the accumulation of indoxyl sulfate is a cause of iron deficiency in patients with CKD. Therefore, we investigated the association between serum indoxyl sulfate concentration and iron dynamics in patients with end-stage kidney disease (ESKD).

Methods

We performed a cross-sectional study on 37 non-dialyzed patients with ESKD, who were hospitalized to undergo maintenance hemodialysis treatment at Shirasagi Hospital. Serum indoxyl sulfate concentration, iron dynamics parameters and other laboratory data were measured immediately before the initiation of hemodialysis treatment. Clinical characteristics were obtained from electronic medical records.

Results

The estimated glomerular filtration rate (eGFR) of 37 patients with ESKD was 5.08 (3.78–7.97) mL/min/1.73 m2 (median [range]). Serum ferritin and transferrin saturation (TSAT) were 90 (10–419) ng/mL and 20 (8–59)% (median [range]), respectively. Serum indoxyl sulfate concentration was 62 (11–182) μM (median [range]). Serum indoxyl sulfate concentration was inversely correlated with serum ferritin level (ρ = − 0.422, p = 0.011), but not with TSAT, age, gender, eGFR and c-reactive protein (CRP) in 37 patients. In eight patients taking iron-containing agents, serum indoxyl sulfate concentration was strongly correlated with serum ferritin level (ρ = − 0.796, p = 0.037); however, in 29 patients not taking an iron-containing agent, this correlation was not observed (ρ = − 0.336, p = 0.076). In the multivariate analysis including age, gender, eGFR and CRP, the correlation between serum indoxyl sulfate concentration tended to be, but not significantly correlated with serum ferritin level in 37 patients (regression coefficient = − 54.343, p = 0.137).

Conclusion

Our study suggests that serum accumulation of indoxyl sulfate is one of causes not to increase serum ferritin level in patients with ESKD taking an iron-containing agent. Further clinical study is needed to reveal the appreciable relationship between serum ferritin and serum indoxyl sulfate.

Iron deficiency contributes to resistance to endogenous erythropoietin in anaemic heart failure patients

AIMS

Abnormal endogenous erythropoietin (EPO) constitutes an important cause of anaemia in chronic diseases. We analysed the relationships between iron deficiency (ID) and the adequacy of endogenous EPO in anaemic heart failure (HF) patients, and the impact of abnormal EPO on 12-month mortality.

METHODS AND RESULTS

We investigated 435 anaemic HF patients (age: 74 ± 10 years; males: 60%; New York Heart Association class I or II: 39%; left ventricular ejection fraction: 43 ± 17%). Patients with EPO higher than expected for a given haemoglobin were considered EPO-resistant whereas those with EPO lower than expected - EPO-deficient. ID was defined as serum ferritin <100 µg/L or 100-299 µg/L with transferrin saturation <20%. EPO-resistant patients (22%) had more advanced HF whereas those with EPO deficiency (57%) were more frequently females and had worse renal function. Lower serum ferritin (indicating depleted body iron stores) was related to higher EPO observed/predicted ratio when adjusted for significant clinical confounders, including C-reactive protein. One year all-cause mortality was 28% in patients with EPO resistance compared to 17% in patients with EPO deficiency and 10% in patients with adequate EPO (log-rank test for the comparison EPO resistance vs. adequate EPO: P = 0.02). When adjusted for other prognosticators, there was still a trend towards increased 12-month mortality in patients with higher EPO level.

CONCLUSION

Anaemic HF patients with endogenous EPO deficiency vs. resistance have different clinical and laboratory characteristics. In such patients, ID contributes to EPO resistance independently of inflammation.

Pancytopenia in children: A 6-year spectrum of patients admitted to Pediatric Department of Rehman Medical Institute, Peshawar

Objective: To determine the various spectrum of pancytopenia with its frequency on the basis of bone marrow examination in children from 6 months to 14 years.

Methods: A retrospective descriptive study was carried out at Department of Pediatric Rehman Medical Institute Peshawar from January 2006 to December 2012. A total of 205 patient’s age between 6 months and 14 years, fulfilling the inclusion and exclusion criteria were included in the study. Complete blood count, peripheral smear, bone marrow examination and Serum vitamin B12 level was done in all the cases.

Results: Out of 14642 patients admitted to the Pediatric department during the study period, 205 (1.4%) patients were pancytopenic on their peripheral blood smear. Male outnumbered female with a ratio of 1.8:1. 42.5% of the patients were in the age group of 1 month to 5 years. Common etiological pattern identified were Aplastic anemia 58(28.3%), Hematological malignancies 49 (23.9%), megaloblastic anemia 40 (19.5%), idiopathic thrombocytopenic purpura 16 (7.8%), iron deficiency anemia 9 (4.4%), hemolytic anemia 7 (3.41%), Visceral leishmaniasis 6 (2.93%), hypersplenism 5 (2.44%), malaria 5 (2.44%), anemia of chronic disorder 4 (1.95%), Myelodisplastic syndrome 3 (1.46%), Niemen pick disease 2 (0.97%) and Gaucher disease in 1(0.49%). Common clinical presentations were fever, pallor, body aches, petechial hemorrhages and epistaxis.

Conclusion: Pancytopenia is one of the importance occurrences in pediatric patients. Acute leukemia and bone marrow failure are the most common causes yet megaloblastic anemia and infections are the treatable and reversible causes of pancytopenia.

Hypertension, left ventricular hypertrophy and chronic kidney disease

Left ventricular hypertrophy (LVH) is a cardiovascular complication highly prevalent in patients with chronic kidney disease (CKD) and end-stage renal disease. LVH in CKD patients has generally a negative prognostic value, because it represents an independent risk factor for the development of arrhythmias, sudden death, heart failure and ischemic heart disease. LVH in CKD patients is secondary to both pressure and volume overload. Pressure overload is secondary to preexisting hypertension, but also to a loss of elasticity of the vessels and to vascular calcifications, leading to augmented pulse pressure. Anemia and the retention of sodium and water secondary to decreased renal function are responsible for volume overload, determining a hyperdynamic state. In particular, the correction of anemia with erythropoietin in CKD patients is advantageous, since it determines LVH reduction. Other risk factors for LVH in CKD patients are documented: some are specific to CKD, as mineral metabolism disorders (hypocalcemia, hyperphosphatemia, low serum vitamin D levels and secondary hyperparathyroidism), others are non-traditional, such as increased asymmetric dimethylarginine, oxidative stress, hyperhomocysteinemia and endothelial dysfunction that, in turn, accelerates the process of atherogenesis, triggers the inflammation and pro-thrombotic state of the glomerular and the vascular endothelium and aggravates the process of both CKD and LVH.

The Cardio‐Renal‐Anemia Syndrome in Elderly Subjects With Heart Failure and a Normal Ejection Fraction: A Comparison With Heart Failure and Low Ejection Fraction

The prevalence and severity of anemia and renal dysfunction in heart failure patients with a normal ejection fraction (HFNEF) is uncharacterized. Two hundred eighty-five consecutive patients admitted to a community hospital with heart failure were stratified by the presence or absence of anemia and a normal or reduced ejection fraction. Comparisons of clinical variables were performed. In this sample, 62% of subjects were anemic, with no difference between those with a normal and a reduced ejection fraction (63% vs. 61%). Anemic HFNEF subjects had a lower glomerular filtration rate (37 +/- 21 mL/min vs. 52 +/- 35 mL/min; p < 0.05) and more severe self-reported symptom scores than nonanemic HFNEF subjects. Multivariate analysis confirmed the association of renal dysfunction and anemia. The authors conclude that the degree and magnitude of anemia in elderly inpatients with heart failure does not differ by ejection fraction. Worse symptoms and more severe renal dysfunction were seen in HFNEF subjects with anemia than in HFNEF subjects without anemia.

Anemia After Renal Transplantation

Anemia in the setting of chronic kidney disease is a well-recognized phenomenon that is associated with decreasing renal function and deficiency of or resistance to erythropoietin. However, anemia in the post-renal transplantation setting has received comparatively less attention in the literature. In this review, we aim critically to appraise the available literature regarding posttransplantation anemia, concentrating in particular on the prevalence of posttransplantation anemia, its etiopathogenesis, potential effects on morbidity and mortality, and the rationale for intervention and treatment. Despite deficiencies in the literature, we conclude that posttransplantation anemia is a common phenomenon that can occur either early or late posttransplantation, and its causation is usually multifactorial and includes contributions notably from poor or decreasing renal function, immunosuppression, and iron deficiency. Conversely, there is a shortage of well-conducted prospective studies looking at the morbidity attributable to posttransplantation anemia and a lack of trial evidence to determine whether intervention improves patient morbidity and outcome.

Cardiovascular Effects of Erythropoietin

We did a PubMed and Cochrane Database System review of different studies on the diverse effects of erythropoietin (EPO), focusing mainly on the cardiovascular system. The direct erythropoietic action of EPO is well studied and widely used. Published studies report dramatic improvement in the course of heart failure with EPO treatment. New controlled clinical trials on large and diverse groups of patients are warranted. Antiapoptotic effects of EPO are newly discovered, opening new horizons in both clinical investigation and therapy. The salvage of cardiomyocytes in acute coronary syndromes, limiting the size of myocardial infarction and improving functional recovery, is only one of multiple potential applications of this effect. Derivatives of EPO with selective antiapoptotic properties seem to hold the best prospects for future studies. Heart failure and ischemic heart disease are potential areas where adding EPO to the conventional treatment may be beneficial.

Post-transplantation anaemia in adult and paediatric renal allograft recipients—Guy's Hospital experience

BACKGROUND

The commonest cause of renal transplant loss is death with a functioning graft, usually from an excess of cardiovascular disease (CVD). Anaemia is becoming increasingly recognized as a reversible risk factor for the development of CVD. The purpose of this study was to estimate the prevalence of post-transplantation anaemia (PTA) in a large population of stable adult and paediatric renal transplants in one centre and to correlate the estimated glomerular filtration rate (eGFR), iron indices and the use of immunosuppressants with the prevalence of anaemia.

METHODS

Every adult and paediatric patient with a functioning renal transplant and more than 3 months post-engraftment at Guy's hospital, London, as of 31 December 2004 and who had a valid creatinine and haemoglobin, in the period 1 September-31 December 2004 inclusive, was identified. A large database of clinical and biochemical indices was built up on the basis of medical notes and electronic patient records. Results were analysed for the prevalence of anaemia and risk factors for its development. Anaemia was defined according to the WHO criteria. All patients on treatment with an erythropoiesis stimulating agent were classified as anaemic, irrespective of haemoglobin.

RESULTS

A total of 878 adults and 73 children were identified. Mean haemoglobin in adults was 12.9 +/- 1.6 g/dl and 11.8 +/- 1.4 g/dl in the children. Mean eGFR was 49.3 +/- 20.1 ml/min in adults and 65.7 +/- 18.8 ml/min in the paediatric cohort. Haemoglobin correlated positively with the eGFR in both cohorts (R = 0.33 and 0.29 in adults and children, respectively (P < 0.0001 for both)). We identified anaemia in 45.3% of adults and 22% in children. Ferritin levels were lower in children than in adults (79 +/- 93 vs 204 +/- 353 mg/l), but were higher in both cohorts among the non-anaemic populations than in those with anaemia. 58% of adults taking mycophenolate mofetil (MMF) were anaemic compared with 22% of children. One child, and 68 adults, were on recombinant erythropoietin. Multiple regression analyses identified age, female gender, eGFR and serum ferritin levels as independent predictors of haemoglobin in adult subjects.

CONCLUSIONS

The prevalence of PTA was high in both adult and paediatric cohorts while comparatively few patients were being treated with erythropoiesis stimulating agents. The strongest predictors of haemoglobin in this cohort of patients were age, female sex and graft function. Immunosuppression including MMF or sirolimus was associated with a higher prevalence of anaemia, but this was likely to be the result of poorer graft function in these subjects. Iron deficiency did not seem to be a causative factor for anaemia in this population.

Effects of Treatment with Epoetin Beta on Outcomes in Patients with Anaemia and Chronic Heart Failure

Anaemia is frequently found in patients with chronic heart failure (CHF) and has been associated with an increase in mortality and morbidity, impaired cardiac and renal function and a reduced quality of life (QoL) compared with non-anaemic CHF patients. Correction of anaemia with recombinant human erythropoietin (epoetin) has been associated with an improvement in CHF in both controlled and uncontrolled studies. The present study describes our findings in a series of 78 consecutive patients with symptomatic CHF and anaemia (haemoglobin (Hb) level <12.0 g/dl) treated with epoetin beta and, if necessary, intravenous iron sucrose. Over a mean observation period of 20.7 +/- 12.1 months, mean Hb levels increased from 10.2 +/- 1.1 to 13.5 +/- 1.2 g/dl, p < 0.01. New York Heart Association (NYHA) functional class, left ventricular ejection fraction (LVEF) were significantly improved and the number of hospitalizations was significantly reduced with the period before treatment (all p < 0.01). Serum creatinine and creatinine clearance (CCr) were 2.2 +/- 0.9 mg/dl and 32.5 +/- 26.5 ml/min, respectively, at baseline, and remained stable over the observation period. Interestingly, >90% of the patients had concomitant mild-to-moderate chronic kidney disease at baseline and study end (CKD), as defined by the accepted diagnostic criterion of a CCr <60 ml/min.

CONCLUSIONS

The correction of the anaemia with epoetin beta together with initial intravenous iron supplementation, resulted in significant improvements in NYHA class and cardiac function, and a reduction in hospitalization rate. Moreover, renal function was maintained stable in most patients.

Managing Anemia in the Critically Ill Patient

Anemia of critical illness is a multifactorial condition caused by phlebotomy, ongoing blood loss, and inadequate production of red blood cells. It occurs early in the course of critical illness. Although red blood cell transfusion is the treatment of choice for immediate management of anemia in the intensive care unit, controversy surrounds the most appropriate hemoglobin concentration or hematocrit "trigger." Therapeutic options, including blood-conservation tools, minimization of phlebotomy, erythropoietic agents, and investigational oxygen-carrying agents, may be alternatives to red blood cell transfusions in critically ill patients with anemia. Patient selection for erythropoietic agents will depend on further work dealing with outcomes and the total cost of care in managing the anemia of critical illness.