Anemia management and chronic renal failure progression

Pro- and Anti-Inflammatory Prostaglandins and Cytokines in Humans: A Mini Review

Inflammation has been described for two millennia, but cellular aspects and the paradigm involving different mediators have been identified in the recent century. Two main groups of molecules, the prostaglandins (PG) and the cytokines, have been discovered and play a major role in inflammatory processes. The activation of prostaglandins PGE2, PGD2 and PGI2 results in prominent symptoms during cardiovascular and rheumatoid diseases. The balance between pro- and anti-inflammatory compounds is nowadays a challenge for more targeted therapeutic approaches. The first cytokine was described more than a century ago and is now a part of different families of cytokines (38 interleukins), including the IL-1 and IL-6 families and TNF and TGFβ families. Cytokines can perform a dual role, being growth promotors or inhibitors and having pro- and anti-inflammatory properties. The complex interactions between cytokines, vascular cells and immune cells are responsible for dramatic conditions and lead to the concept of cytokine storm observed during sepsis, multi-organ failure and, recently, in some cases of COVID-19 infection. Cytokines such as interferon and hematopoietic growth factor have been used as therapy. Alternatively, the inhibition of cytokine functions has been largely developed using anti-interleukin or anti-TNF monoclonal antibodies in the treatment of sepsis or chronic inflammation.

Interplay between chronic kidney disease (CKD) and upper tract urothelial carcinomas (UUC): foe or friend?

Although upper tract urothelial carcinomas (UUC) is curable through nephrectomy or nephroureterectomy, progression of chronic kidney disease (CKD) and CKD-related mortality have been highlighted as clinical challenges in recent years owing to the loss of a large number of nephrons. While CKD can promote the development of UUC, other risk factors such as hypertension, diabetes mellitus, advanced age, and anemia can facilitate the progression of CKD. Conversely, CKD is especially prevalent in UUC patients. However, the relationship between CKD and UUC, mechanisms for CKD causing UUC, and gender disparity of UUC of CKD patients have so far not been well-reviewed. As UUC gradually grows, the cancer can be a physical obstacle in the urinary tract. It will cause an increased tract pressure, subsequently resulting in the dysfunction of both nephrons and kidney. At the molecular level, reduced level of oxidative stress was observed in female UUC patients. Furthermore, radical nephrectomy therapy for UUC patients accelerates the progress of chronic kidney dysfunction. Incidentally, the remedies for CKD containing aristolochic acid (AA) are carcinogenic. Our present review offers a comprehensive look at the relationship between CKD and UUC from multiple perspectives. Early and precise identification of progression of CKD and UUC will benefit the patients at high-risk of CKD or UUC, which will also be instructive in directing timely and effective therapeutic interventions whenever necessary. It may also shed light on unveiling the underlying mechanisms of carcinogenesis of UUC, preventing CKD progression, and prolonging the patients' overall survival.

Carbamylated Erythropoietin Outperforms Erythropoietin in the Treatment of AKI-on-CKD and Other AKI Models

Erythropoietin (EPO) may be a beneficial tissue-protective cytokine. However, high doses of EPO are associate with adverse effects, including thrombosis, tumor growth, and hypertension. Carbamylated erythropoietin (CEPO) lacks both erythropoietic and vasoconstrictive actions. In this study, we compared the renoprotective, hemodynamic, and hematologic activities and survival effects of identical EPO and CEPO doses in rat models of clinically relevant AKI presentations, including ischemia-reperfusion-induced AKI superimposed on CKD (5000 U/kg EPO or CEPO; three subcutaneous injections) and ischemia-reperfusion-induced AKI in old versus young animals and male versus female animals (1000 U/kg EPO or CEPO; three subcutaneous injections). Compared with EPO therapy, CEPO therapy induced greater improvements in renal function and body weight in AKI on CKD animals, with smaller increases in hematocrit levels and similarly improved survival. Compared with EPO therapy in the other AKI groups, CEPO therapy induced greater improvements in protection and recovery of renal function and survival, with smaller increases in systolic BP and hematocrit levels. Overall, old or male animals had more severe loss in kidney function and higher mortality rates than young or female animals, respectively. Notably, mRNA and protein expression analyses confirmed the renal expression of the heterodimeric EPO receptor/CD131 complex, which is required for the tissue-protective effects of CEPO signaling. In conclusion, CEPO improves renal function, body and kidney weight, and survival in AKI models without raising hematocrit levels and BP as substantially as EPO. Thus, CEPO therapy may be superior to EPO in improving outcomes in common forms of clinical AKI.

Management of anemia in patients with diabetic kidney disease: A consensus statement

This consensus statement focuses on the window of opportunity, which exists while treating patients with diabetic kidney disease and anemia.

Predictors of anemia in a multi-ethnic chronic kidney disease population: a case-control study

Anemia is a common complication of chronic kidney disease (CKD). However, risk factors of anemia in CKD patients in Singapore are not well established. Hence, a retrospective, case–control study involving non-dialysis CKD patients was conducted to determine possible predictors of anemia in the local CKD population.

Non-dialysis adult CKD patients, not receiving renal replacement therapy or erythropoiesis-stimulating-agents were included. Parameters collected included demographics e.g. age, sex and race; clinical data e.g. CKD stage and medical/medication histories; and laboratory data e.g. serum electrolytes, urinary and hematologic parameters. Patients were classified as anemic or non-anemic using a threshold hemoglobin level of 10 g/dL. The parameters were evaluated for their predictive value for anemia development using multivariate logistical regression and calculation of odds ratios. Statistical analyses were performed using STATA.

A total of 457 patients (162 anemic and 295 non-anemic) were analysed. Multivariate analysis showed that probability of developing anemia was greater for patients with stage 5 CKD (OR 16.76, p < 0.001), with hematological disorders (OR 18.61, p < 0.001) and with respiratory disorders (OR 4.54, p = 0.004). The probability of developing anemia was lower for patients with higher previous hemoglobin concentration (OR 0.32, p < 0.001) and in those receiving iron supplements (OR 0.44, p = 0.031). Gender and race were not found to be significant predictors of anemia.

Risk of anemia is increased in patients with advanced CKD, haematological disorders, respiratory disorders, and those not taking iron supplements. This study has increased our understanding of the patient subgroups at risk for anemia.

Cost of managing anemia in end-stage renal disease: the experience of five French dialysis centers

OBJECTIVE

The aim of this retrospective study was to evaluate the direct cost of anemia treatment in hemodialysis patients and to evidence factors predictive of 1-year cost.

METHODS

Retrospective study which included hemodialyzed patients during year 2009 in five centers. Patients were evaluable if they had at least one hemoglobin (Hb) assay per month and were monitored for at least 4 months. Patients were classified in different "annual Hb category" according to their monthly mean Hb [Hb categories: Ideal (10 ≤ Hb ≤ 12 g/dL); High (Hb > 12 g/dL) and Low (Hb < 10 g/dL) if >75% of time in respective category, otherwise classified in the Fluctuating category].

RESULTS

We analyzed 636 patients (male, 59.4%) with a mean age of 67 years who underwent 144 hemodialysis sessions (median number per patient) in 2009. The cost of anemia treatment was largely driven by erythropoiesis-stimulating agents (ESA) (68% of total cost for Low Hb category and approximately 90% for the other Hb categories). Adjusted predictive factors for 1-year direct cost of anemia treatment (p < 0.0001) were dialysis center (<euro>2,518-<euro>5,617), death (<euro>6,091 vs. <euro>4,911), age (<euro>4,911 for ≤55 years and <euro>5,378 for 65-75 years), female gender (<euro>4,911 vs. <euro>4,398 for male), Low Hb category (<euro>13,005 vs. <euro>5,034 for Ideal, <euro>4,911 for Fluctuating and <euro>2,418 for High), serum ferritin level (<euro>5,102 for 200-500 μg/mL and <euro>4,646 for ≥500 μg/mL) and duration of dialysis (<euro>4,911 if ≤2 years and <euro>2,952 if 4-6 years).

LIMITATIONS

Retrospective study, and low number of patients in the Low Hb category.

CONCLUSIONS

The main factors that were predictive of 1-year cost of anemia treatment in hemodialysis patients were centers, patients in the Low Hb category, and dialysis duration of less than 2 years.

A nonerythropoietic derivative of erythropoietin inhibits tubulointerstitial fibrosis in remnant kidney

BACKGROUND

The tissue-protective effects of erythropoietin (EPO) have been extensively investigated, and EPO administration can raise the hemoglobin (Hb) concentration. Recently, we reported that carbamylated erythropoietin (CEPO) protected kidneys from ischemia-reperfusion injury as well as EPO.

METHODS

To investigate the clinical applications of CEPO, we next evaluated the long-term therapeutic effect of CEPO using a tubulointerstitial model rat. We randomized remnant kidney model rats to receive saline, EPO, or CEPO for 8 weeks.

RESULTS

CEPO- and EPO-treated rats had improved serum creatinine levels compared with saline-treated remnant kidney model rats, although the Hb level was significantly increased in EPO-treated rats. Two-photon microscopy revealed that EPO/CEPO significantly ameliorated tubular epithelial cell damage assessed by endocytosis. In addition, CEPO or EPO protected endothelial cells with a sustained blood flow rate. EPO or CEPO suppressed the number of TUNEL-positive apoptotic cells with weak αSMA staining. Furthermore, PCR analysis demonstrated that TGF-β and type I collagen expression was attenuated in EPO- or CEPO-treated rats, accompanied by a significant decrease in interstitial fibrosis.

CONCLUSION

We established a long-term therapeutic approach to protect tubulointerstitial injury with CEPO, and thus, the therapeutic value of this approach warrants further attention and preclinical studies.

Carbamylated Erythropoietin Ameliorates Cyclosporine Nephropathy without Stimulating Erythropoiesis

The introduction of cyclosporine (CsA) has improved graft survival, but it causes nephropathy, which limits its clinical utility. Recently, we reported that carbamylated erythropoietin (CEPO) protected kidneys from ischemia reperfusion injury as well as EPO. To investigate the clinical applications of CEPO, we next evaluated the long-term therapeutic effect of CEPO using a CsA-induced nephropathy model. CsA caused renal dysfunction, while EPO/CEPO administration significantly improved renal function. EPO treatment significantly increased Hb concentration, while CEPO treatment neither enhanced nor reduced Hb concentration. CsA treatment induced tubular apoptosis, while EPO/CEPO administration inhibited it and increased PI3 kinase activation and Akt phosphorylation. In parallel, morphological assessment revealed that EPO/CEPO significantly reduced CsA-induced interstitial fibrosis and inhibited interstitial macrophage infiltration. In addition, real-time RT-PCR demonstrated that cortical mRNA levels of TGF-β1 and type I collagen were suppressed in the EPO/CEPO group. These results suggest a new therapeutic approach using CEPO to protect kidneys from CsA-induced nephropathy.

Gender effect on renal outcome in patients with urothelial carcinoma

PURPOSE

Taiwan is a highly endemic area for urothelial carcinoma (UC) and chronic kidney disease (CKD). We evaluate the gender effect on the relationship between renal outcome and clinical characteristics of CKD patients with UC.

METHODS

The clinical and pathologic records of 404 patients were retrospectively analyzed. We calculated glomerular filtration rate (GFR) using the Modification of Diet in Renal Disease (MDRD) equation, and staged CKD status according to K/DOQI guideline.

RESULTS

The female group had a significantly higher proportion (67.6% vs 29.0%, P < 0.001) of upper urinary tract urothelial carcinoma (UUT-UC). Pathologically, the frequency of high T stage UC (32.4% and 19.1%; P = 0.003), high-grade UC (89.4% and 75.6%; P = 0.001), and larger UC (51.4% and 37.8%; P = 0.009) in the female patients were significantly higher, when compared with the male group. Male gender, diabetes, anemia, poor preoperative renal function, UUT-UC, and low-grade tumor were independent risk factors of poor renal outcome by multivariate analysis in these UC patients. Diabetes was a risk factor of poor renal outcome in male UUT-UC patients, but not in the female patients (P = 0.009).

CONCLUSION

Female gender had a more aggressive histological urothelial carcinoma pattern than male patients did, but paradoxically had a more favorable renal outcome.

Meeting New Challenges in the Management of Anemia of Chronic Kidney Disease Through Collaborative Care with Pharmacists

Objective:

To evaluate chronic kidney disease (CKD)–associated anemia management challenges and limitations and discuss strategies to improve treatment rates and patient response to therapy, monitoring of patient response to therapy, and education of prescribing providers and patients.

Data Sources:

Multiple MEDLINE searches were performed using a comprehensive search term list to identify studies for inclusion, including, but not limited to, anemia, erythropoiesis-stimulating agent (ESA), epoetin, darbepoetin, CERA, hemoglobin, CKD, dialysis, end-stage renal disease, quality of life, and pharmacist. Annual data reports and clinical practice guidelines published by the National Kidney Foundation and US Renal Data System were included. Information provided within product package inserts for recombinant human erythropoietin (epoetin alfa; Epogen, Procrit) and darbepoetin alfa (Aranesp) were also included.

Study Selection and Data Extraction:

Only articles that were published in English and were relevant for this review were included.

Data Synthesis:

Anemia is a common complication of CKD, with significant impact on patients' quality of life. Anemia of CKD represents a significant burden on the healthcare system, with ESA use resulting in substantial financial costs. As new therapies, formularies, and dosing regimens evolve, the collaborative role of the clinical pharmacist is integral to a multidisciplinary treatment strategy, both in the inpatient and outpatient settings, such as hospitals or dialysis centers, respectively. This review focuses on initial and target hemoglobin (Hb) concentrations, as well as patient characteristics, treatment preferences, and dosing schedules, which are important considerations in managing CKD-associated anemia. To ensure effective therapeutic strategies, a patient-centered approach is required. Pharmacists are ideally positioned to help select ESA therapy, influence formulary use, educate healthcare professionals and patients, develop and implement dosing and monitoring protocols, and possibly promote quality improvement.

Conclusions:

An approach to CKD-associated anemia management that involves collaboration with pharmacists is essential to achieve patient-specific, cost-effective ESA therapy.

Serum hepcidin concentration in chronic haemodialysis patients: associations and effects of dialysis, iron and erythropoietin therapy

BACKGROUND

Hepcidin, a liver-derived peptide induced by iron overload and inflammation, is a major regulator of iron homeostasis. As hepcidin decreases gastrointestinal iron absorption and recirculation from monocytes, over-expression is associated with the development of anaemia.

METHODS

We studied the associations between circulating hepcidin levels and various laboratory parameters related to anaemia and/or inflammation in 20 patients on chronic haemodialysis. Furthermore, we determined the impact of dialysis and iron and/or erythropoietin (rhEpo) supplementation therapy on hepcidin serum concentrations. The patients were withheld from iron and rhEpo for 2 weeks before study entry. Hepcidin was measured by liquid chromatography-mass spectrometry (LC-MS/MS); serum iron and haematological parameters, cytokines and pro-hepcidin by commercially available enzyme-linked immunosorbent assays (ELISA) or standard automated methods.

RESULTS

While hepcidin levels at baseline were not correlated to pro-hepcidin, interleukin-6 or transforming growth factor-beta concentrations, we found significant associations with reticulocyte count (r = -0.55; P = 0.015), serum iron (r = 0.7; P = 0.004) and ferritin levels (r = 0.63; P = 0.004) and transferrin saturation (r = 0.69, P = 0.001). Dialysis using either a high or a low flux biocompatible dialyser resulted in a significant decrease of hepcidin concentrations, which returned to pre-dialysis values before the next dialysis session. When studying the effects of anaemia treatment, we observed a significant reduction of hepcidin levels following administration of rhEpo but not iron.

CONCLUSIONS

Hepcidin levels in stable haemodialysis patients appear to reflect systemic iron load, but not inflammation. Due to the negative association between reticulocyte counts and hepcidin, the reduction of circulating hepcidin concentrations by dialysis and/or rhEpo treatment may positively affect erythropoiesis.

Carbamylated Erythropoietin Improves Angiogenesis and Protects the Kidneys from Ischemia-Reperfusion Injury

Several studies have shown that erythropoietin (EPO) can protect the kidneys from ischemia-reperfusion injury and can raise the hemoglobin (Hb) concentration. Recently, the EPO molecule modified by carbamylation (CEPO) has been identified and was demonstrated to be able to protect several organs without increasing the Hb concentration. We hypothesized that treatment with CEPO would protect the kidneys, partly due to the increased peritubular capillaries. The therapeutic effect of CEPO was evaluated using an endothelial tube formation assay in vitro, and a rat ischemia-reperfusion injury model in vivo. EPO treatment showed the tendency of increased tube formation, while CEPO treatment induced more capillary-like formation than EPO. Ischemia-reperfusion-induced kidneys exhibited characteristic nuclei of apoptosis in tubular epithelial cells with decreased peritubular capillaries, while EPO treatment inhibited tubular apoptosis with preserved endothelial cells. Moreover, CEPO-treated kidneys showed minimal tubular apoptosis with increased peritubular capillary endothelial cells. In conclusion, we identified a new therapeutic approach using CEPO to protect kidneys from ischemia-reperfusion injury by promoting angiogenesis.

Evaluation of aortic stiffness in children with chronic renal failure

The measurement of aortic stiffness (As) [aortic strain (S), pressure strain elastic modulus (Ep) and pressure strain normalized by diastolic pressure (Ep*)] is suggested as an excellent marker of subclinical arterial sclerosis. We aimed to investigate the presence of As and to determine the relationship between As and some risk factors in children with chronic renal failure (CRF). Twenty-six pre-dialysis (PreD) [female/male (F/M) 7/19] patients and 23 chronic peritoneal dialysis (CPD) (F/M 13/10) patients were assessed. Twenty-nine healthy children were selected as a control group (F/M 14/15). We determined anemia, abnormal calcium/phosphate metabolism, hypertension, diastolic dysfunction, increased left ventricular mass (LVM), hypertriglyceridemia, increased stiffness (Ep, Ep*), and decreased strain (S) in the CRF (PreD and CPD) group compared with the controls (P < 0.05). Presence of renal disease, LVM and usage of angiotensin-converting enzyme inhibitor (ACE-I) in all groups; female gender, duration of disease and the usage of anti-hypertensive drug therapy in CRF patients; and LVM and LVM index in healthy children were found to be independent predictors for aortic stiffness and/or strain. In conclusion, CRF is associated with significant arterial functional abnormalities in uremic children and not controlled by dialysis treatment. These results suggest that, even in young children, uremia has a profound impact on arterial function.

Treating anemia of chronic kidney disease in the primary care setting: cardiovascular outcomes and management recommendations

Anemia is an underrecognized but characteristic feature of chronic kidney disease (CKD), associated with significant cardiovascular morbidity, hospitalization, and mortality. Since their inception nearly two decades ago, erythropoiesis-stimulating agents (ESAs) have revolutionized the care of patients with renal anemia, and their use has been associated with improved quality of life and reduced hospitalizations, inpatient costs, and mortality. Hemoglobin targets >/=13 g/dL have been linked with adverse events in recent randomized trials, raising concerns over the proper hemoglobin range for ESA treatment. This review appraises observational and randomized studies of the outcomes of erythropoietic treatment and offers recommendations for managing renal anemia in the primary care setting.

Carbamylated erythropoietin protects the kidneys from ischemia-reperfusion injury without stimulating erythropoiesis

Several studies have shown that erythropoietin (EPO) can protect the kidneys from ischemia-reperfusion injury and can raise the hemoglobin (Hb) concentration. Recently, the EPO molecule modified by carbamylation (CEPO) has been identified and was demonstrated to be able to protect several organs without increasing the Hb concentration. We hypothesized that treatment with CEPO would protect the kidneys from tubular apoptosis and inhibit subsequent tubulointerstitial injury without erythropoiesis. The therapeutic effect of CEPO was evaluated using a rat ischemia-reperfusion injury model. Saline-treated kidneys exhibited increased tubular apoptosis with interstitial expression of alpha-smooth muscle actin (alpha-SMA), while EPO treatment inhibited tubular apoptosis and alpha-SMA expression to some extent. On the other hand, CEPO-treated kidneys showed minimal tubular apoptosis with limited expression of alpha-SMA. Moreover, CEPO significantly promoted tubular epithelial cell proliferation without erythropoiesis. In conclusion, we identified a new therapeutic approach using CEPO to protect kidneys from ischemia-reperfusion injury.

Intrarenal oxygenation in chronic renal failure

In chronic renal failure (CRF), renal impairment correlates with tubulointerstitial fibrosis characterized by inflammation, interstitial expansion with accumulation of extracellular matrix (ECM), tubular atrophy and vascular obliteration. Tubulointerstitial injury subsequent to glomerular sclerosis may be induced by proteinuria, leakage of glomerular filtrate or injury to the post-glomerular peritubular capillaries (hypoxia). In vivo data in animal models suggest that CRF is associated with hypoxia, with the decline in renal Po2 preceding ECM accumulation. Chronic renal failure is characterized by loss of microvascular profiles but, in the absence of microvascular obliteration, hypoxia can occur by a variety of complementary mechanisms, including anaemia, decreased capillary flow, increased vasoconstriction, increased metabolic demand and increased diffusion distances due to ECM deposition. Hypoxia regulates a wide array of genes, including many fibrogenic factors. Hypoxia-inducible factors (HIF) are the major, but not the sole, transcriptional regulators in the hypoxic response. In CRF, hypoxia may play a role in the sustained inflammatory response. In vitro studies in tubulointerstitial cells suggest that hypoxia can induce profibrogenic changes in proximal tubular epithelial cells and interstitial fibroblasts consistent with changes observed in CRF in vivo. The effect of hypoxia on renal microvascular cells warrants investigation. Hypoxia may play a role in the recruitment, retention and differentiation of circulating progenitor cells to the kidney contributing to the disease process and may also affect intrinsic stem cell populations. Chronic hypoxia in CRF fails to induce a sustained angiogenic response. Therapeutic manipulation of the hypoxic response may be of benefit in slowing progression of CRF. Potential therapies include correction of anaemia, inhibition of the renin-angiotensin system, administration of exogenous pro-angiogenic factors to protect the microvasculature, activation of HIF and hypoxia-mediated targeting of engineered progenitor cells.