Recent and Emerging Therapies for Iron Deficiency in Anemia of CKD: A Review

Can we effectively manage chronic kidney disease with a precision-based pharmacotherapy plan? Where are we?

INTRODUCTION

In recent years, thanks to significant advances in basic science and biotechnologies, nephrology has witnessed a deeper understanding of the mechanisms leading to various conditions associated with or causing kidney disease, opening new perspectives for developing specific treatments. These new possibilities have brought increased challenges to physicians, who face with a new complexity in disease characterization and selection the right treatment for individual patients.

AREAS COVERED

We chose four therapeutic situations: anaemia in chronic kidney disease (CKD), heart failure in CKD, IgA nephropathy (IgAN) and membranous nephropathy (MN). The literature search was made through PubMed.

EXPERT OPINION

Anaemia management remains challenging in CKD; a personalized therapeutic approach is often needed. Identifying patients who could benefit from a specific therapy is also an important goal for patients with CKD and heart failure with reduced ejection fraction. Several new treatments are under clinical development for IgAN; interestingly, they target specifically the pathogenetic mechanisms of the disease. The understanding of MN pathogenesis as an autoimmune disease and the discovery of several autoantibodies allows a better characterization of patients. High-sensible techniques for lymphocyte counting open the possibility of more personalized use of anti CD20 therapies.

Indole Lactic Acid in Plasma and Urine: A Potential Biomarker for Chronic Kidney Disease and Inflammatory

Purpose

We aimed to explore changes in plasma and urine indole lactic acid (ILA) levels and the relationship between inflammation and ILA in chronic kidney disease (CKD) patients and healthy people.

Patients and Methods

Forty-seven CKD patients and 30 healthy individuals were included in this study. One-way ANOVA was used for variables with normal distribution and homogeneous variance. A rank-sum test was performed for non-normally distributed variables. Correlation analyses were performed using Pearson's or Spearman correlation analyses. Independent relationship between patients and CKD was analyzed using ordinal and binary logistic regressions. Receiver operating characteristic (ROC) curve was used.

Results

Plasma and urine ILA levels were positively correlated (r = 0.51, P < 0.01). Plasma ILA was positively correlated with BMI, age, creatinine, BUN, triglycerides, and uric acid and negatively correlated with hemoglobin levels. Urine ILA levels were positively correlated with age, creatinine, BUN, and uric acid and negatively correlated with hemoglobin and albumin levels. Ordered logistic regression analysis showed that CKD was significantly correlated with plasma ILA (OR=4.49, P < 0.01), urinary ILA (OR=2.14,P < 0.01), urea levels (OR=1.43, P < 0.01) and hemoglobin levels (OR=0.95, P < 0.01) were significantly related. ROC curves indicated that plasma and urinary ILA were reliable predictors of CKD. CKD was correlated with plasma, urine ILA (OR=5.92, P < 0.01; OR=2.79, P < 0.01) and Hs-CRP (OR=2.45, P < 0.01).

Conclusion

Plasma and urine ILA can potentially be used as biomarkers of CKD and inflammatory status.

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.

Exploring progress in iron supplement formulation approaches for treating iron deficiency anemia through bibliometric and thematic analysis

Anemia is a severe health issue that affects around one-third of the global population. Therefore, the present study aims to conduct a bibliometric analysis to investigate the research trends regarding advancements on iron formulations in treating iron deficiency anemia via oral or parenteral route. This study adopts thematic and bibliometric methods on existing research on novel iron formulations. It also provides perspective into the existing understanding on treatment strategies for iron deficiency anemia. This study is conducted on 543 papers on various ferrous and ferric formulations used in the treatment of iron deficiency anemia. The study period is from 1977 to 2022, and the papers are identified from the Scopus database. The bibliometric analysis was carried out using the R tool's Bibliometrix package. The study discusses performance analysis, including annual publications, geographic analysis, relevant affiliations, journal analysis, and citation analysis. In addition, the conceptual structure, including the co-occurrence network, thematic map, thematic evolution, intellectual structure highlighting co-citation analysis, and social structure depicting the collaboration network and collaboration world map, are presented. The results showed increased research on formulation strategies for the treatment of iron deficiency anemia from 2010 onwards. The top 5 contributing countries are the USA, Italy, India, Germany, and the UK, and peer-reviewed journals from the area of nutrition. The most trending areas of study are iron deficiency anemia in pregnancy, chronic kidney diseases, inflammatory bowel diseases, and various intravenous formulations used in its treatment. The authors from Europe collaborate the most with authors from other countries. The study concludes that a safer and more effective iron formulation is needed to reduce the prevalence of anemia. The findings of the study are helpful in advancing research on innovative formulations for treating iron deficiency anemia. The insights from the study are helpful to policymakers in designing specific health policies and investing more in research and development of novel formulations for the treatment of iron deficiency anemia.

Ferric citrate for the treatment of hyperphosphatemia and iron deficiency anaemia in patients with NDD-CKD: a systematic review and meta-analysis

Background: The application of ferric citrate therapy has yielded unexpected benefits in recent years for Chronic kidney disease patients suffering from hyperphosphatemia and iron deficiency -anaemia. Despite this, earlier research on the impact of ferric citrate on NDD-CKD has been contentious. Objective: The goal of the meta-analysis is to evaluate the evidence regarding the advantages and dangers of ferric citrate for the treatment of hyperphosphatemia and iron deficiency anaemia in NDD-CKD patients. Methods: Between the start of the study and June 2022, we searched PubMed, Embase, Cochrane, EBSCO, Scopus, Web of Science, Wan Fang Data, CNKI, and VIP databases for randomised controlled trials of iron citrate for hyperphosphatemia and anaemia in patients with NDD-CKD. For binary categorical data, risk ratios (OR) were employed, and for continuous variables, weighted mean differences The effect sizes for both count and measurement data were expressed using 95% confidence intervals Results: The meta-analysis includes eight trials with a total of 1281 NDD-CKD patients. The phosphorus-lowering effect of ferric citrate was greater compared to the control group (WMD, -0.55, 95% CI, -0.81 to -0.28; I2 = 86%, p < 0.001). Calcium (WMD, 0.092; 95% CI, -0.051 to 0.234; p > 0.05; I2 = 61.9%), PTH (WMD, -0.10; 95% CI, -0.44 to 0.23; I2 = 75%, p > 0.05) and iFGF23 (WMD, -7.62; 95% CI, -21.18 to 5.94; I2 = 20%, p > 0.05) levels were not statistically different after ferric citrate treatment compared to control treatment. Furthermore, ferric citrate increased iron reserves and haemoglobin. The ferric citrate group had considerably greater levels than the controls. Ferric citrate, on the other hand, may raise the risk of constipation, diarrhoea, and nausea. Conclusion: This meta-analysis found that ferric citrate had a beneficial effect in the treatment of NDD-CKD, particularly in reducing blood phosphorus levels when compared to a control intervention. It also shown that ferric citrate has a favourable effect on iron intake and anaemia management. In terms of safety, ferric citrate may increase the likelihood of gastrointestinal side effects.

Observation of the efficacy of parathyroidectomy for secondary hyperparathyroidism in hemodialysis patients: a retrospective study

PURPOSE

Parathyroidectomy (PTX) is commonly performed as a treatment for secondary hyperparathyroidism (SHPT) in patients with end-stage renal disease (ESRD). We aimed to evaluate the efficacy of PTX in patients with SHPT who underwent hemodialysis.

METHODS

This retrospective study analyzed the clinical treatment of 80 hemodialysis patients with SHPT who underwent either total PTX with forearm auto transplantation (TPTX + AT) or subtotal parathyroidectomy (SPTX). We compared the changes in biochemical indices before and after surgery as well as the attenuation of intact parathyroid hormone (iPTH) in the TPTX and SPTX groups. We also evaluated clinical symptoms and quality of life using the Visual Analog Scale (VAS) and the Short Form-36 Questionnaire (SF-36) before and at 3, 6, and 12 months after surgery.

RESULTS

Serum iPTH and serum phosphorus levels decreased significantly after surgery in 80 patients with SHPT (P < 0.05). Within one month of surgery, there was a difference in iPTH levels between the TPTX + AT and SPTH groups, but there was no difference over time. Patients experienced significant improvement in their clinical symptoms of restless leg syndrome, skin itching, bone pain, and joint pain at 1 week post operation (P < 0.001). Quality of life significantly improved after surgery, as assessed by SF-36 scores (P < 0.05). Hypocalcemia was the most common postoperative complication, occurring in 35% of patients. Within the first 12 months post surgery, 5 patients had a recurrence.

CONCLUSION

PTX is effective in rapidly reducing iPTH levels, improving calcium and phosphorus metabolism disorders, and enhancing patients' quality of life by safely and effectively relieving clinical symptoms.

Treatment Options for Anemia in Kidney Transplant Patients: A Review

Anemia is common after kidney transplantation. The etiology may be multifactorial, such as causes of anemia in the general population and causes that are unique to the kidney transplant setting. Posttransplant anemia, particularly when severe, may be associated with adverse effects such as graft failure, mortality, and a decline in kidney function. After careful investigation, that is, having excluded or treated reversible causes of anemia, treatment of anemia in patients with a kidney transplant is based on iron supplementation or erythropoiesis-stimulating agents (ESA), although there are no specific guidelines on anemia management in this patient population. Iron therapy is often needed, but optimal and safe iron-deficiency management strategies remain to be defined. Evidence suggests that ESAs are safe and potentially associated with favorable outcomes. Better graft function has been reported with ESA use targeting hemoglobin levels higher than those recommended in the general population with chronic kidney disease and with no apparent increased risk of cardiovascular events. These results require further investigation. Data on the use of hypoxia-inducible factor inhibitors are limited. Prevention and treatment of anemia in kidney transplantation can improve patients' quality of life, life expectancy, allograft function, and survival.

Natural History of Anemia and Efficacy and Safety of Oral Iron Therapy in Children Newly Diagnosed With Inflammatory Bowel Disease

OBJECTIVES

Anemia is one of the most common extraintestinal manifestations of pediatric inflammatory bowel disease (IBD). We aimed to evaluate the prevalence of anemia in children newly diagnosed with IBD and assess the efficacy and safety of oral iron therapy over a 12-month follow-up period.

METHODS

This single-center, retrospective, observational cohort study included all children newly diagnosed with IBD at the Pediatric Gastroenterology Unit of Sapienza University of Rome from May 2015 to May 2019 presenting with anemia. At baseline, demographic, clinical, laboratory data (hemoglobin, mean corpuscular volume, serum iron, ferritin, transferrin levels, erythrocyte sedimentation rate, and C-reactive protein), and treatment received, were recorded. Clinical and laboratory data, as well as anemia therapy and adverse events (AEs), were collected every 3 months during the 1-year follow-up.

RESULTS

Eighty-nine out of 140 patients newly diagnosed with IBD presented with anemia (64%); 13 were excluded due to incomplete follow-up, thus 76 were included [median age 12.7 (interquartile range 9.8-15), 25 (33%) Crohn disease, 51 (67%) ulcerative colitis]. All patients received sucrosomial iron (SI) alone or in combination with intravenous ferric carboxymaltose. Treatment with SI was effective in 67 (88%) patients at the end of follow-up [37 (48%) within 3 months], regardless of anemia severity at baseline. No serious AEs related to SI treatment were reported.

CONCLUSIONS

We confirmed a high prevalence of anemia at the time of the diagnosis of pediatric IBD. Our data suggest that SI is safe and effective, leading to anemia resolution in approximately half of the patients within 3 months.

Ferric Carboxymaltose and Erythropoiesis-Stimulating Agent Treatment Reduces the Rate of Blood Transfusion in Refractory Anemia

Background: Erythropoiesis-stimulating agents (ESAs) are used to treat refractory anemia (RA). Guidelines suggest iron supplementation for unresponsive patients, regardless of iron deficiency. The primary aim of this study was to evaluate the effect of iron supplementation with ferric carboxymaltose (FCM) on the reduction of red blood cell transfusion (RBCT) rate in transfusion-dependent RA patients. Methods: This was a prospective quasi-randomized study, wherein patients were randomly assigned into three groups: (A) ESAs alone, (B) ferric gluconate (FG) and ESAs, and (C) FCM and ESAs. Hemoglobin and ferritin levels, as well as the number of RBCTs at 4 and 28 weeks were compared. Economic evaluation was also performed. Results: A total of 113 RA patients were enrolled. In total, 43 were treated with intravenous FG and ESAs, 38 with FCM and ESAs, and 32 with ESAs alone. At both follow-ups, erythropoietic response was increased in those receiving iron as compared with those with ESAs alone (p = 0.001), regardless of the type of iron. At one month, ferritin levels were higher in the FCM and ESA groups (p = 0.001). RBCTs were lower in both iron groups. The less costly treatment strategy was FCM, followed by FG, and lastly ESAs. Conclusions: Addition of iron to ESAs in RA reduced RBCT requirement and improved hemoglobin values.