Risk of iron overload with chronic indiscriminate use of intravenous iron products in ESRD and IBD populations

Efficacy and Safety of Oral Supplementation with Liposomal Iron in Non-Dialysis Chronic Kidney Disease Patients with Iron Deficiency

INTRODUCTION

Iron deficiency is common in patients with non-dialysis-dependent chronic kidney disease (NDD-CKD). Oral iron supplementation is recommended in these patients, but it is associated with a higher incidence of gastrointestinal adverse reactions. Liposomal iron therapy has been proposed as a new iron formulation, improving iron bioavailability with less side effects; however, few data are available in patients with NDD-CKD.

METHODS

We designed a single-arm pilot study to evaluate the efficacy of liposomal iron administered for six months in correcting iron deficiency (defined as serum ferritin < 100 ng/mL and/or transferrin saturation < 20%) in patients with NDD-CKD stages 1-5. The primary endpoints were the achievement of serum ferritin ≥ 100 ng/mL and transferrin saturation ≥ 20%. Secondary outcomes were hemoglobin (Hb) changes and the safety of liposomal iron.

RESULTS

The efficacy population included 34/38 patients, who completed at least one visit after baseline. Liposomal iron increased the achievement of transferrin saturation targets from 11.8% at baseline to 50.0% at month 6 (p = 0.002), while no significant correction of serum ferritin (p = 0.214) and Hb was found (p = 0.465). When patients were stratified by anemia (Hb < 12 g/dL in women and Hb < 13 g/dL in men), a significant improvement of transferrin saturation was observed only in anemic patients (from 13.3 ± 5.8% to 20.2 ± 8.1%, p = 0.012). Hb values slightly increased at month 6 only in anemic patients (+0.60 g/dL, 95%CI -0.27 to +1.48), but not in those without anemia (+0.08 g/dL, 95%CI -0.73 to +0.88). In patients taking at least one dose of liposomal iron (safety population, n = 38), the study drug was discontinued in eight patients due to death (n = 2), a switch to intravenous iron (n = 2), and the occurrence of side effects (n = 4).

CONCLUSIONS

The use of liposomal iron in patients with NDD-CKD is associated with a partial correction of transferrin saturation, with no significant effect on iron storage and Hb levels.

Iron oxide nanoparticles trigger endoplasmic reticulum damage in steatotic hepatic cells

Iron oxide nanoparticles (IONPs) are being actively researched in various biomedical applications, particularly as magnetic resonance imaging (MRI) contrast agents for diagnosing various liver pathologies like nonalcoholic fatty liver diseases, nonalcoholic steatohepatitis, and cirrhosis. Emerging evidence suggests that IONPs may exacerbate hepatic steatosis and liver injury in susceptible livers such as those with nonalcoholic fatty liver disease. However, our understanding of how IONPs may affect steatotic cells at the sub-cellular level is still fragmented. Generally, there is a lack of studies identifying the molecular mechanisms of potential toxic and/or adverse effects of IONPs on "non-heathy" in vitro models. In this study, we demonstrate that IONPs, at a dose that does not cause general toxicity in hepatic cells (Alexander and HepG2), induce significant toxicity in steatotic cells (cells loaded with non-toxic doses of palmitic acid). Mechanistically, co-treatment with PA and IONPs resulted in endoplasmic reticulum (ER) stress, accompanied by the release of cathepsin B from lysosomes to the cytosol. The release of cathepsin B, along with ER stress, led to the activation of apoptotic cell death. Our results suggest that it is necessary to consider the interaction between IONPs and the liver, especially in susceptible livers. This study provides important basic knowledge for the future optimization of IONPs as MRI contrast agents for various biomedical applications.

Lysosomal nanotoxicity: Impact of nanomedicines on lysosomal function

Although several nanomedicines got clinical approval over the past two decades, the clinical translation rate is relatively small so far. There are many post-surveillance withdrawals of nanomedicines caused by various safety issues. For successful clinical advancement of nanotechnology, it is of unmet need to realize cellular and molecular foundation of nanotoxicity. Current data suggest that lysosomal dysfunction caused by nanoparticles is emerging as the most common intracellular trigger of nanotoxicity. This review analyzes prospect mechanisms of lysosomal dysfunction-mediated toxicity induced by nanoparticles. We summarized and critically assessed adverse drug reactions of current clinically approved nanomedicines. Importantly, we show that physicochemical properties have great impact on nanoparticles interaction with cells, excretion route and kinetics, and subsequently on toxicity. We analyzed literature on adverse reactions of current nanomedicines and hypothesized that adverse reactions might be linked with lysosomal dysfunction caused by nanomedicines. Finally, from our analysis it becomes clear that it is unjustifiable to generalize safety and toxicity of nanoparticles, since different particles possess distinct toxicological properties. We propose that the biological mechanism of the disease progression and treatment should be central in the optimization of nanoparticle design.

Hepatic and cardiac iron overload quantified by magnetic resonance imaging in patients on hemodialysis: A systematic review and meta-analysis

INTRODUCTION

Few studies have reported hepatic and cardiac iron overload in patients with end-stage renal disease (ESRD), and the current evidence regarding the prevalence is still scarce.

AIM

This review aims to estimate the prevalence of hepatic and/or cardiac iron overload quantified by magnetic resonance imaging (MRI) in patients with ESRD who receive hemodialysis (HD), peritoneal dialysis (PD), or have undergone a kidney transplant.

METHODS

A systematic review with meta-analysis was conducted and reported in line with PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) guidelines. MEDLINE and Embase bibliographic databases were searched using a comprehensive list of controlled vocabulary and keywords to identify relevant studies. All studies reporting the prevalence of hepatic and/or cardiac iron overload quantified by MRI in ESRD patients were considered. The Newcastle-Ottawa scale was used to assess the methodological quality of included studies. To investigate the heterogeneity between studies, random-effect meta-analyses for proportions were used.

RESULTS

The review comprised seven studies that included 339 patients. Using meta-analysis, the pooled prevalence of severe and mild to moderate hepatic iron overload quantified by MRI was 0.23 [95% CI: 0.08-0.43] and 0.52 [95% CI: 0.47-0.57], respectively. Only three studies included cardiac iron quantification, and none reported iron overload.

CONCLUSIONS

This review has revealed a high prevalence of severe hepatic iron overload in patients with ESRD treated by HD. Further studies with a larger sample size are needed to determine the impact of iron overload on vital organs in patients with ESRD and guide future research in this understudied field. Proper use of iron chelation and continuous monitoring will help in the early detection of unsolicited complications; however, the low renal clearance of most iron chelators limits the options for treating iron excess in patients with ESRD.

Individualized anemia management enhanced by ferric pyrophosphate citrate protocol

The optimal use of erythropoiesis-stimulating agents (ESAs) and parenteral iron in managing anemia in end-stage renal disease (ESRD) remains controversial. One-size-fits-all rule-based algorithms dominate dosing protocols for ESA and parenteral iron. However, the Food & Drug Administration (FDA) guidelines for using ESAs in chronic kidney disease recommend individualized therapy for the patient. This prospective quality assurance project was at a single hemodialysis (HD) center comprising three 6-month phases (A, B, C) separated by 3-month washout periods. Standard bi-weekly ESA dose titration and intravenous (IV) iron sucrose protocols were used in baseline Phase A, and ferric pyrophosphate citrate (FPC) augmented iron in Phase B. In Phase C, an FPC protocol and weekly, individualized ESA management were used. We examined clinic-level mean differences in hemoglobin (Hb) and ESRD-related outcomes by phase with repeated ANOVA. To examine the Hb at the patient level, we used multi-level mixed-effect regression adjusting for phase, month, and other relevant confounders at each month over time to derive the mean marginal effects of phase. There were 54, 78, and 66 patients in phases A, B, and C, respectively, with raw mean Hb values of 9.9, 10.2, and 10.3 g/dL. The percentage of Hb values < 9 g/dL declined from 14.3% in Phase A to 7.6% in Phase C (p = 0.007). The multivariable mixed-effect regression results showed mean marginal Hb was higher by 0.3 mg/dL and 0.4 mg/dL in Phases B and C, respectively, compared to Phase A. We also observed reduced ferritin (p = 0.003) and transferrin saturation (TSAT) (p = 0.008) levels from Phase A to Phase C with the repeated ANOVA analysis. Ferric pyrophosphate citrate (FPC) appears to support more efficient ESA-stimulated erythropoiesis. Moreover, individualized ESA management combined with FPC (Phase C) was associated with further improvement in efficiency as we observed the fewest patients with Hb values < 9 g/dL concurrent with greater decreases in ferritin levels and reduced ESA doses. However, future prospective studies to confirm these findings on a larger, more diverse cohort of ESRD patients are warranted.

Differential Pharmacokinetics of Liver Tropism for Iron Sucrose, Ferric Carboxymaltose, and Iron Isomaltoside: A Clue to Their Safety for Dialysis Patients

Anemia is a major complication of end-stage kidney disease (ESKD). Erythropoiesis-stimulating agents and intravenous (IV) iron are the current backbone of anemia treatment in ESKD. Iron overload induced by IV iron is a potential clinical problem in dialysis patients. We compared the pharmacokinetics of liver accumulation of iron sucrose, currently used worldwide, with two third-generation IV irons (ferric carboxymaltose and iron isomaltoside). We hypothesized that better pharmacokinetics of newer irons could improve the safety of anemia management in ESKD. Liver iron concentration (LIC) was analyzed in 54 dialysis patients by magnetic resonance imaging under different modalities of iron therapy. LIC increased significantly in patients treated with 1.2 g or 2.4 g IV iron sucrose (p < 0.001, Wilcoxon test), whereas no significant increase was observed in patients treated with ferric carboxymaltose or iron isomaltoside (p > 0.05, Wilcoxon-test). Absolute differences in LIC reached 25 μmol/g in the 1.2 g iron sucrose group compared with only 5 μmol/g in the 1 g ferric carboxymaltose and 1 g iron isomaltoside groups (p < 0.0001, Kruskal−Wallis test). These results suggest the beneficial consequences of using ferric carboxymaltose or iron isomaltoside on liver structure in ESKD due to their pharmacokinetic ability to minimize iron overload.

Iron imbalance in cancer: Intersection of deficiency and overload

Iron, an essential trace element, plays a complex role in tumour biology. While iron causes cancer clearance through toxic free radical generation, iron‐induced free radical flux also acts as a cancer promoter. These fates majorly guided through cellular response towards pro‐oxidant and antioxidant settings in a tumour microenvironment, designate iron‐induced oxidative stress as a common yet paradoxical factor in pro‐tumorigenesis as well as anti‐tumorigenesis, posing a challenge to laying down iron thresholds favouring tumour clearance. Additionally, complexity of iron's association with carcinogenesis has been extended to iron‐induced ROS's involvement in states of both iron deficiency and overload, conditions identified as comparable, inevitable and significant coexisting contributors as well as outcomes in chronic infections and tumorigenesis. Besides, iron overload may also develop as an unwanted outcome in certain cancer patients, as a result of symptomatic anaemia treatment owed to irrational iron‐restoration therapies without a prior knowledge of body's iron status with both conditions synergistically acting towards tumour aggravation. The co‐play of iron deficiency and overload along with iron's pro‐tumour and antitumour roles with intersecting mechanisms, thus presents an unpredictable regulatory response loop in a state of malignancy. The relevance of iron's thresholds beyond which it proves to be beneficial against tumorigenesis hence becomes questionable. These factors pose a challenge, over establishing if iron chelation or iron flooding acts as a better approach towards antitumour therapies. This review presents a critical picture of multiple contrasting features of iron's behaviour in cancer, leading towards two conditions lying at opposite ends of a spectrum: iron deficiency and overload in chronic disease conditions including cancer, hence, validating the critical significance of diagnosis of patients' iron status prior to opting for subsequent therapies.

Long-Term Effectiveness of Oral Ferric Maltol vs Intravenous Ferric Carboxymaltose for the Treatment of Iron-Deficiency Anemia in Patients With Inflammatory Bowel Disease: A Randomized Controlled Noninferiority Trial

BACKGROUND

Iron-deficiency anemia is common in inflammatory bowel disease, requiring oral or intravenous iron replacement therapy. Treatment with standard oral irons is limited by poor absorption and gastrointestinal toxicity. Ferric maltol is an oral iron designed for improved absorption and tolerability.

METHODS

In this open-label, phase 3b trial (EudraCT 2015-002496-26 and NCT02680756), adults with nonseverely active inflammatory bowel disease and iron-deficiency anemia (hemoglobin, 8.0-11.0/12.0 g/dL [women/men]; ferritin, <30 ng/mL/<100 ng/mL with transferrin saturation <20%) were randomized to oral ferric maltol 30 mg twice daily or intravenous ferric carboxymaltose given according to each center's standard practice. The primary endpoint was a hemoglobin responder rate (≥2 g/dL increase or normalization) at week 12, with a 20% noninferiority limit in the intent-to-treat and per-protocol populations.

RESULTS

For the intent-to-treat (ferric maltol, n = 125/ferric carboxymaltose, n = 125) and per-protocol (n = 78/88) analyses, week 12 responder rates were 67% and 68%, respectively, for ferric maltol vs 84% and 85%, respectively, for ferric carboxymaltose. As the confidence intervals crossed the noninferiority margin, the primary endpoint was not met. Mean hemoglobin increases at weeks 12, 24, and 52 were 2.5 vs 3.0 g/dL, 2.9 vs 2.8 g/dL, and 2.7 vs 2.8 g/dL with ferric maltol vs ferric carboxymaltose. Treatment-emergent adverse events occurred in 59% and 36% of patients, respectively, and resulted in treatment discontinuation in 10% and 3% of patients, respectively.

CONCLUSIONS

Ferric maltol achieved clinically relevant increases in hemoglobin but did not show noninferiority vs ferric carboxymaltose at week 12. Both treatments had comparable long-term effectiveness for hemoglobin and ferritin over 52 weeks and were well tolerated.

INFERR-Iron infusion in haemodialysis study: INtravenous iron polymaltose for First Nations Australian patients with high FERRitin levels on haemodialysis-a protocol for a prospective open-label blinded endpoint randomised controlled trial

Background

The effectiveness of erythropoiesis-stimulating agents, which are the main stay of managing anaemia of chronic kidney disease (CKD), is largely dependent on adequate body iron stores. The iron stores are determined by the levels of serum ferritin concentration and transferrin saturation. These two surrogate markers of iron stores are used to guide iron replacement therapy. Most Aboriginal and/or Torres Islander Australians of the Northern Territory (herein respectfully referred to as First Nations Australians) with end-stage kidney disease have ferritin levels higher than current guideline recommendations for iron therapy. There is no clear evidence to guide safe and effective treatment with iron in these patients. We aim to assess the impact of intravenous iron treatment on all-cause death and hospitalisation with a principal diagnosis of all-cause infection in First Nations patients on haemodialysis with anaemia, high ferritin levels and low transferrin saturation

Methods

In a prospective open-label blinded endpoint randomised controlled trial, a total of 576 participants on maintenance haemodialysis with high ferritin (> 700 μg/L and ≤ 2000 μg/L) and low transferrin saturation (< 40%) from all the 7 renal units across the Northern Territory of Australia will be randomised 1:1 to receive intravenous iron polymaltose 400 mg once monthly (200 mg during 2 consecutive haemodialysis sessions) (Arm A) or no IV iron treatment (standard treatment) (Arm B). Rescue therapy will be administered when the ferritin levels fall below 700 μg/L or when clinically indicated. The primary outcome will be the differences between the two study arms in the risk of hospitalisation with all-cause infection or death. An economic analysis and several secondary and tertiary outcomes analyses will also be performed.

Discussion

The INFERR clinical trial will address significant uncertainty on the safety and efficacy of iron therapy in First Nations Australians with CKD with hyperferritinaemia and evidence of iron deficiency. This will hopefully lead to the development of evidence-based guidelines. It will also provide the opportunity to explore the causes of hyperferritinaemia in First Nations Australians from the Northern Territory.

Trial registration

This trial is registered with The Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12620000705987. Registered 29 June 2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05854-w.

Anemia: A Connection Between Heart Failure and Kidney Failure

Erythropoiesis-stimulating agents (ESAs) have improved the quality of life and reduced the need for transfusions in patients with chronic kidney disease. However, randomized trials showed no benefit but possible safety issues following high doses of ESAs given to reach normal hemoglobin levels. Iron therapy is used together with ESA; when given proactively, it may reduce the risk of mortality and cardiovascular events in hemodialysis patients. Recent trials also showed benefits of intravenous iron therapy in patients with heart failure. New drugs for correcting anemia may retain the present efficacy of ESAs as antianemic drugs and reduce cardiovascular risks.

MRI-Based Quantitative R2* Mapping at 3 Tesla Reflects Hepatic Iron Overload and Pathogenesis in Nonalcoholic Fatty Liver Disease Patients

BACKGROUND

The role of hepatic iron overload (HIO) in nonalcoholic fatty liver disease (NAFLD) pathogenesis has not been fully elucidated.

PURPOSE

This study aimed to investigate the effect of HIO and examine the diagnostic usefulness of magnetic resonance imaging (MRI)-based R2^* quantification in evaluating hepatic iron content (HIC) and pathological findings in NAFLD.

STUDY TYPE

Prospective and retrospective.

POPULATION

A prospective study of 168 patients (age, 57.2 ± 15.0; male/female, 80/88) and a retrospective validation study of 202 patients (age, 57.0 ± 14.4; male/female, 113/89) with liver-biopsy-confirmed NAFLD were performed.

FIELD STRENGTH/SEQUENCE

3 T; chemical-shift encoded multi-echo gradient echo.

ASSESSMENT

Using liver tissues obtained by liver biopsy, HIC was prospectively evaluated in 168 patients by atomic absorption spectrometry. Diagnostic accuracies of HIC and R2^* for grading hepatic inflammation plus ballooning (HIB) as an indicator of NAFLD activity were assessed.

STATISTICAL TESTS

Student's t-test and analysis of variance (ANOVA) with Scheffe's multiple testing correction for univariate comparisons; multivariate logistic analysis. P-value less than 0.05 is statistically significant.

RESULTS

HIC was significantly correlated with HIB grades (r = 0.407). R2^* was significantly correlated with HIC (r = 0.557) and HIB grades (r = 0.569). R2^* mapped an area under the receiver operating characteristic (AUROC; 0.774) for HIC ≥808 ng/mL (median value) with cutoff value of 62.5 s^-1 . In addition, R2^* mapped AUROC of HIB for grades ≥3 was 0.799 with cutoff value of 58.5 s^-1 . When R2^* was <62.5 s^-1 , R2^* correlated weakly with HIC (r = 0.372) as it was affected by fat deposition and did not correlate with HIB grades (P = 0.052). Conversely, when R2^* was ≥62.5 s^-1 , a significant correlation of R2^* with HIC (r = 0.556) and with HIB grades was observed (P < 0.0001) with being less affected by fat deposition.

DATA CONCLUSION

R2^*  ≥ 62.5 s^-1 is a promising modality for non-invasive diagnosis of clinically important high grades (≥3) of HIB associated with increased HIC.

LEVEL OF EVIDENCE

1 TECHNICAL EFFICACY STAGE: 2.

Narrative Review of Hyperferritinemia, Iron Deficiency, and the Challenges of Managing Anemia in Aboriginal and Torres Strait Islander Australians With CKD

Aboriginal and Torres Strait Islander Australians (Indigenous Australians) suffer some of the highest rates of chronic kidney disease (CKD) in the world. Among Indigenous Australians in remote areas of the Northern Territory, prevalence rates for renal replacement therapy (RRT) are up to 30 times higher than national prevalence. Anemia among patients with CKD is a common complication. Iron deficiency is one of the major causes. Iron deficiency is also one of the key causes of poor response to the mainstay of anemia therapy with erythropoiesis-stimulating agents (ESAs). Therefore, the effective management of anemia in people with CKD is largely dependent on effective identification and correction of iron deficiency. The current identification of iron deficiency in routine clinical practice is dependent on 2 surrogate markers of iron status: serum ferritin concentration and transferrin saturation (TSAT). However, questions exist regarding the use of serum ferritin concentration in people with CKD because it is an acute-phase reactant that can be raised in the context of acute and chronic inflammation. Serum ferritin concentration among Indigenous Australians receiving RRT is often markedly elevated and falls outside reference ranges within most national and international guidelines for iron therapy for people with CKD. This review explores published data on the challenges of managing anemia in Indigenous people with CKD and the need for future research on the efficacy and safety of treatment of anemia of CKD in patients with high ferritin and evidence iron deficiency.

Iron supplementation and iron-fortified foods: a review

About one-third of the world population is suffering from iron deficiency. Delivery of iron through diet is a practical, economical, and sustainable approach. Clinical studies have shown that the consumption of iron-fortified foods is one of the most effective methods for the prevention of iron deficiency. However, supplementing iron through diet can cause undesirable side-effects. Thus, it is essential to develop new iron-rich ingredients, iron-fortified products with high bioavailability, better stability, and lower cost. It is also essential to develop newer processing technologies for more effective fortification. This review compared the iron supplementation strategies used to treat the highly iron-deficient population and the general public. We also reviewed the efficacy of functional (iron-rich) ingredients that can be incorporated into food materials to produce iron-fortified foods. The most commonly available foods, such as cereals, bakery products, dairy products, beverages, and condiments are still the best vehicles for iron fortification and delivery.Scope of reviewThe manuscript aims at providing a comprehensive review of the latest publications that cover three aspects: administration routes for iron supplementation, iron-rich ingredients used for iron supplementation, and iron-fortified foods.

Long-Term Prognosis of Hyperferritinemia Induced by Intravenous Iron Therapy in Patients Undergoing Maintenance Hemodialysis: A 10-Year, Single-Center Study

Optimal ferritin level in hemodialysis patients between Japan and other countries is controversial. Long-term side effects of iron supplementation in these patients remain unclear. We aimed to elucidate whether past hyperferritinemia in hemodialysis patients was associated with high risk of death and cerebrovascular and cardiovascular diseases (CCVDs). This small retrospective cohort study included approximately 44 patients unintentionally supplemented with excessive intravenous iron. A significantly higher risk of CCVDs was observed in patients with initial serum ferritin levels ≥1000 ng/mL than in the remaining patients. High ferritin levels slowly decreased to <300 ng/mL in a median of 24.2 (10.5–46.5) months without treatment. However, compared with the remaining patients, only patients whose ferritin levels did not decrease to <300 ng/mL steadily had a significantly higher risk of all-cause death (hazard ratio, 9.6). Long-term hyperferritinemia due to intravenous iron therapy is a risk factor for death in maintenance hemodialysis patients. For a prolonged better prognosis, intravenous iron should be carefully administered so as to avoid hyperferritinemia in patients with hemodialysis.

Safety profile of intravenous iron in inflammatory bowel disease: an up-to-date overview

Up to 30-70% of patients may experience mild and moderate side effects during iron therapy and this is often associated with a poor adherence to therapy. Anemia is frequent in patients with active inflammatory bowel disease (IBD), due to both iron deficiency and chronic inflammation, therefore iron supplementation is frequently needed. Considering that gastrointestinal disorders are the most common side effects with oral iron, in IBD patients intravenous administration must be preferred. Although intravenous iron supplementation remains the most effective therapy of IBD-associated iron deficiency anemia, the perception of risk related to intravenous administration by clinicians could limit this successful strategy. In this narrative review we provided an up to date on the safety of the different iron formulations for intravenous administration, by reporting the most recent studies in IBD patients.

The pathogenesis of CKD complications; Attack of dysregulated iron and phosphate metabolism

Chronic kidney disease (CKD) patients have a tremendously higher risk of developing cardiovascular disease (CVD) and infection than the non-CKD population, which could be caused by intertwining actions of hyperphosphatemia and CKD associated misdistribution of iron. CVD is often associated with vascular calcification, which has been attributed to hyperphosphatemia, and could be initiated in mitochondria, inducing apoptosis, and accelerated by reactive oxygen species (ROS). The production of ROS is principally linked to intracellular ferrous iron. For infection, the virulence and pathogenicity of a pathogen is directly related to its capacity to acquire iron for proliferation and to escape or subvert the host's immune response. Iron administration for renal anemia can sometimes be overdosed, which could decrease host immune mechanisms through its direct effect on neutrophils, macrophages and T cell function. Hyperphosphatemia has been demonstrated to be associated with an increased incidence of infection. We hypothesized two possible mechanisms: 1) fibroblast growth factor-23 levels are increased in parallel with serum phosphate levels and directly impair leukocyte recruitment and host defense mechanisms, and 2) circulating non-transferrin-bound iron (NTBI) is increased due to decreased iron binding capacity of the carrier protein transferrin in high-phosphate conditions. From these observations, maintaining an adequate serum range of phosphate levels and minimizing intracellular iron accumulation could attenuate the development of CKD complications.

Hypoxia-inducible factor prolyl hydroxylase inhibitors: a paradigm shift for treatment of anemia in chronic kidney disease?

INTRODUCTION

The hypoxia-inducible factor prolyl hydroxylase (HIF-PH) pathway is responsible for regulating the biosynthesis of erythropoietin (EPO) and maintaining iron homeostasis. Investigational drugs that target the HIF-PH pathway are promising alternatives for treating anemia in Chronic Kidney Disease (CKD).

AREAS COVERED

This review summarizes recent advances focused on the clinical development of HIF-PH inhibitors (HIF-PHIs) as potentially novel therapies in the treatment of anemia in CKD based on publications available on PubMed and restricted Google searches. We provide a comparison between HIF-PHIs regarding their pharmacokinetics, dosing regimens and safety concerns, structure-activity relationships, and alterations in key laboratory parameters observed in animal models and clinical trials.

EXPERT OPINION

HIF-PHIs may be advantageous in some aspects compared to the conventional erythropoiesis-stimulating agents (ESAs). While ESAs could increase the risk of cardiovascular events due to rapid rises in ESA blood levels, HIF-PHIs have been reported to maintain EPO concentrations at levels that are closer to the normal physiological ranges. Although HIF-PHIs have been demonstrated to be relatively safe and effective in clinical trials, long-term safety data are needed in order to establish whether these therapeutic agents will lead to a major paradigm change in the treatment of anemia of CKD.

Real-world evaluation of an intravenous iron service for the treatment of iron deficiency in patients with gastroenterological disorders

BACKGROUND

In gastroenterological disorders, iron deficiency (ID) is often treated with intravenous iron. This real-world study assessed the effectiveness and safety of iron isomaltoside (IIM), a high-dose intravenous iron, for the treatment of ID in patients with gastroenterological disorders, as part of a service evaluation and improvement process.

METHODS

Medical records of 117 patients with gastroenterological disorders, who received IIM, were examined retrospectively. Study outcomes included dose of IIM (estimated iron need versus actual dose received), number of appointments required to deliver the dose and changes in haemoglobin (Hb) and ferritin at ~1 month and ~6 months post-treatment. Safety was assessed through adverse drug reactions (ADRs).

RESULTS

Overall, 76.1% of patients received their estimated iron need; 23.9% were underdosed. The mean (SD) iron dose was 1317 (409.7) mg; 62.4% of patients received their dose in one appointment. From baseline, mean (SD) Hb increased by 20.9 (15.4) g/L at 1 month post-treatment (p<0.0001) and by 22.0 (17.9) g/L at 6 months post-treatment (p<0.0001). Mean (SD) baseline ferritin was 26.6 (37.8) μg/L, which increased to 234.6 (142.9) μg/L at 1 month post-treatment (p<0.0001), and remained increased at 6 months post-treatment (122.8 (99.2) μg/L; p<0.0001). A substantial proportion of patients were non-anaemic at 1 month (57.5%) and 6 months (61.8%) post-treatment. At both post-treatment timepoints, the proportion of non-anaemic patients was higher in those receiving their total iron need versus those who were underdosed. No serious ADRs were reported.

CONCLUSION

IIM was efficacious and well tolerated in patients with gastroenterological disorders. This real-world study highlights the importance of administering the full iron need to maximise treatment response.

Histological Scores Validate the Accuracy of Hepatic Iron Load Measured by Signal Intensity Ratio and R2* Relaxometry MRI in Dialysis Patients

Almost all haemodialysis patients are treated with parenteral iron to compensate for blood loss and to allow the full therapeutic effect of erythropoiesis-stimulating agents. Iron overload is an increasingly recognised clinical situation diagnosed by quantitative magnetic resonance imaging (MRI). MRI methods have not been fully validated in dialysis patients. We compared Deugnier’s and Turlin’s histological scoring of iron overload and Scheuer’s classification (with Perls’ stain) with three quantitative MRI methods for measuring liver iron concentration (LIC)—signal intensity ratio (SIR), R2* relaxometry, and R2* multi-peak spectral modelling (Iterative Decomposition of water and fat with Echo Asymmetry and Least-squares estimation (IDEAL-IQ^®)) relaxometry—in 16 haemodialysis patients in whom a liver biopsy was formally indicated for medical follow-up. LIC MRI with these three different methods was highly correlated with Deugnier’s and Turlin’s histological scoring (SIR: r = 0.8329, p = 0.0002; R2* relaxometry: r = −0.9099, p < 0.0001; R2* relaxometry (IDEAL-IQ^®): r = −0.872, p = 0.0018). Scheuer’s classification was also significantly correlated with these three MRI techniques. The positive likelihood ratio for the diagnosis of abnormal LIC by Deugnier’s histological scoring was > 62 for the three MRI methods. This study supports the accuracy of quantitative MRI methods for the non-invasive diagnosis and follow-up of iron overload in haemodialysis patients.