Anemia of chronic disease: pathophysiology and laboratory diagnosis

Prognostic Value of the Combination of HB (hemoglobin) and CEA in Resectable Gastric Cancer

Objective: In order to investigate the prognostic value of a novel biomarker combining serum carcinoembryonic antigen (CEA) and hemoglobin (HB) levels in patients with resectable gastric cancer.

Introduction: This retrospective study assessed the relationship between CEA, hemoglobin levels, a novel combined prognostic biomarker (HB-CEA) and clinicopathological features of gastric cancer. Their prognostic values in gastric cancer were also analyzed.

Materials and Methods: This retrospective study evaluated the CEA, hemoglobin levels and clinicopathological features of patients with resectable gastric cancer. Kaplan-Meier curves, univariate and multivariate Cox proportional models were used to determine the prognostic significance of these factors for overall survival (OS) in the training and validation sets (n=353 and n=388, respectively). Based on optimal cutoff values of CEA and hemoglobin (3.395 ng/mL and 125.5 g/L, respectively), patients were stratified into three groups: HB-CEA=0, 1, and 2 (CEA <3.395 ng/mL and HB ≥125.5 g/L; CEA ≥3.395 ng/mL or HB <125.5 g/L; and CEA ≥3.395 ng/mL and HB <125.5 g/L, respectively).

Results: The area under the curve was larger for HB-CEA than for either HB or CEA alone (training set: 0.677, 0.650, and 0.629; validation set: 0.670, 0.605, and 0.605, respectively). HB-CEA was strongly associated with age, tumor size, differentiation, pathological TNM stage (pTNM), depth of tumor invasion, lymph node metastasis, and survival status (all p<0.05). A higher HB-CEA score correlated with poor survival (Kaplan-Meier curves, all p<0.05). Multivariate analysis showed that HB-CEA was an independent prognostic factor for OS (p<0.05).

Conclusion: Preoperative HB-CEA, as a potential novel hematological biomarker, can predict the progression of gastric cancer and the prognosis of patients, and is of great value in guiding clinical practice. Therefore, patients with a higher HB-CEA score should receive more extensive follow-up for early detection and intervention of tumor progression.

Zinc protoporphyrin levels in COVID-19 are indicative of iron deficiency and potential predictor of disease severity

Background

Coronavirus disease (COVID-19) has a severe impact on all aspects of patient care. Among the numerous biomarkers of potential validity for diagnostic and clinical management of COVID-19 are biomarkers at the interface of iron metabolism and inflammation.

Methods

The follow-up study included 54 hospitalized patients with laboratory-confirmed COVID-19 with a moderate and severe/critical form of the disease. Iron deficiency specific biomarkers such as iron, ferritin, transferrin receptor, hepcidin, and zinc protoporphyrin (ZnPP) as well as relevant markers of inflammation were evaluated twice: in the first five days when the patient was admitted to the hospital and during five to 15 days; and their validity to diagnose iron deficiency was further assessed. The regression and Receiver Operating Characteristics (ROC) analyses were performed to evaluate the prognosis and determine the probability for predicting the severity of the disease in the first five days of COVID-19.

Results

Based on hemoglobin values, anemia was observed in 21 of 54 patients. Of all iron deficiency anemia-related markers, only ZnPP was significantly elevated (P<0.001) in the anemic group. When patients were grouped according to the severity of disease, slight differences in hemoglobin or other anemia-related parameters could be observed. However, the levels of ZnPP were significantly increased in the severely ill group of patients. The ratio of ZnPP to lymphocyte count (ZnPP/L) had a discrimination power stronger than the neutrophil to lymphocyte count ratio (N/L) to determine disease severity. Additionally, only two markers were independently associated with the severity of COVID-19 in logistic regression analysis; D-dimer (OR (5.606)(95% CI 1.019–30.867)) and ZnPP/L ratio (OR (74.313) (95% CI 1.081–5108.103)).

Conclusions

For the first time ZnPP in COVID-19 patients were reported in this study. Among all iron-related markers tested, ZnPP was the only one that was associated with anemia as based on hemoglobin. The increase in ZnPP might indicate that the underlying cause of anemia in COVID-19 patients is not only due to the inflammation but also of nutritional origin. Additionally, the ZnPP/L ratio might be a valid prognostic marker for the severity of COVID-19.

Physiology and Inflammation Driven Pathophysiology of Iron Homeostasis-Mechanistic Insights into Anemia of Inflammation and Its Treatment

Anemia is very common in patients with inflammatory disorders. Its prevalence is associated with severity of the underlying disease, and it negatively affects quality of life and cardio-vascular performance of patients. Anemia of inflammation (AI) is caused by disturbances of iron metabolism resulting in iron retention within macrophages, a reduced erythrocyte half-life, and cytokine mediated inhibition of erythropoietin function and erythroid progenitor cell differentiation. AI is mostly mild to moderate, normochromic and normocytic, and characterized by low circulating iron, but normal and increased levels of the storage protein ferritin and the iron hormone hepcidin. The primary therapeutic approach for AI is treatment of the underlying inflammatory disease which mostly results in normalization of hemoglobin levels over time unless other pathologies such as vitamin deficiencies, true iron deficiency on the basis of bleeding episodes, or renal insufficiency are present. If the underlying disease and/or anemia are not resolved, iron supplementation therapy and/or treatment with erythropoietin stimulating agents may be considered whereas blood transfusions are an emergency treatment for life-threatening anemia. New treatments with hepcidin-modifying strategies and stabilizers of hypoxia inducible factors emerge but their therapeutic efficacy for treatment of AI in ill patients needs to be evaluated in clinical trials.

Dynamics in Anemia Development and Dysregulation of Iron Homeostasis in Hospitalized Patients with COVID-19

Anemia and disturbances of iron metabolism are frequently encountered in patients with COVID-19 and associated with an adverse clinical course. We retrospectively analyzed 645 consecutive COVID-19 patients hospitalized at the Innsbruck University Hospital. Pre-existing anemia was associated with increased risk for in-hospital death. We further found that the decline in hemoglobin levels during hospital stay is more pronounced in patients with signs of hyperinflammation upon admission, the latter being associated with a nearly two-fold higher risk for new onset anemia within one week. Anemia prevalence increased from 44.3% upon admission to 87.8% in patients who were still hospitalized after two weeks. A more distinct decrease in hemoglobin levels was observed in subjects with severe disease, and new-onset anemia was associated with a higher risk for ICU admission. Transferrin levels decreased within the first week of hospitalization in all patients, however, a continuous decline was observed in subjects who died. Hemoglobin, ferritin, and transferrin levels normalized in a median of 122 days after discharge from hospital. This study uncovers pre-existing anemia as well as low transferrin concentrations as risk factors for mortality in hospitalized COVID-19 patients, whereas new-onset anemia during hospitalization is a risk factor for ICU admission. Anemia and iron disturbances are mainly driven by COVID-19 associated inflammation, and cure from infection results in resolution of anemia and normalization of dysregulated iron homeostasis.

Iron deficiency anemia in IBD: an overlooked comorbidity

Introduction: Iron Deficiency Anemia (IDA) is a leading cause of anemia in Inflammatory Bowel disease (IBD). IDA affects quality of life (QoL) and lead to developmental and cognitive abnormalities. Diagnosis of IDA in IBD is complicated as biochemical tests available at present cannot help distinguish between IDA and anemia of chronic disease. Soluble transferrin receptor ferritin index has been gaining popularity as it can diagnose IDA in presence of chronic inflammation. ECCO guidelines recommend a Hb increase of >2 g/dL and a TfS of >30% within 4 weeks as adequate therapeutic response. IV iron is preferred over oral iron as it bypasses gastrointestinal tract, rapidly increases haemoglobin, and is not associated with intestinal inflammation. Our aim in this review is to provide apathway for physicians to help them diagnose and appropriately treat IDA in IBD.Areas covered: In this review article, we have discussed current diagnosis and treatment in detail and have proposed new directions on how future research can help manage IDA in IBD effectively.Expert opinion: Understanding the pathogenesis of IDA in IBD will further lead to exploring new potential diagnostic tests and treatment regimens for effective management of IDA in IBD.

Evaluation of reticulocyte hemoglobin content (RETIC-HGB) for the diagnosis of iron-limited erythropoiesis in cats

BACKGROUND

Decreased reticulocyte hemoglobin content (CHr) (Siemens ADVIA 2120) reflects iron-limited erythropoiesis (ILE). RETIC-HGB (IDEXX ProCyte Dx) is a novel marker of ILE for veterinary use.

OBJECTIVES

We aimed to evaluate reference intervals (RIs) and the utility of RETIC-HGB and CHr in the diagnosis of feline ILE.

MATERIALS AND METHODS

RIs were established in 59 healthy cats. Intra-assay coefficients of variation (CVs) and correlations between RETIC-HGB and CHr were assessed. Two hundred and seventy-five cats were classified as having ILE or not based on low plasma iron or low transferrin saturation along with anemia and/or altered RBC indices. CHr, RETIC-HGB, and serum amyloid A (SAA) were compared between the groups. The sensitivity and specificity of RETIC-HGB and CHr to diagnose ILE were analyzed to determine the RI lower limits.

RESULTS

RIs for RETIC-HGB and CHr were 12.5-18.0 and 14.0-19.9 pg, respectively. The CV was 3% for both variables. RETIC-HGB and CHr were moderately correlated (r_s = 0.59) with a bias of -1.2 picograms (pgs). Twenty of the 275 cats were classified as having ILE. Compared with non-ILE cats, ILE cats had significantly lower median RETIC-HGB (14.3 vs 15.2 pg, P = .0046) and mean CHr (14.7 vs 16.5 pg, P < .0001) values and significantly increased median SAA (44.6 vs 2.3 µg/dl, P < .0001) values. Using the lower RI limits resulted in a low sensitivity and relatively high specificity to diagnose ILE in cats.

CONCLUSIONS

ILE was characterized by decreased CHr and RETIC-HGB; however, sensitivity was low. The moderate correlation between RETIC-HGB and CHr is likely due to species differences and different methodology.

HPO iron chelator, CP655, causes the G1/S phase cell cycle block via p21 upregulation

Iron is known not only for its importance in cellular and metabolic pathways but also for its role in causing cellular toxicities such as production of reactive oxygen species and growth of pathogens. The inability of the human body to physiologically excrete excess iron highlights the need to develop a cheap yet effective iron chelator. This study provides initial evidence of the therapeutic and prophylactic properties of 3-hydroxypyridin-4-one (HPO) chelators in murine collagen-induced arthritis. To determine whether these chelators would be effective on human cells, we tested a panel of different HPO chelators and identified 7-diethylamino-N-((5-hydroxy-6-methyl-4-oxo-1,4-dihydropyridin-3-yl)methyl)-N-methyl-2-oxo-chromen-3-carboxamide (CP655) as the most effective compound targeting human CD4+ T cells. Treatment with CP655 causes significant inhibition of cell proliferation and production of inflammatory cytokines such as interferon-γ and interleukin-17. Microarray analysis revealed dysregulation in cell cycle-related genes following CP655 treatment. This was validated by flow cytometry demonstrating a G1/S phase block caused by CP655. Finally, mechanistic experiments revealed that the chelator may be causing an upregulation of the cell cycle inhibitor protein CDKN1A (p21) as a possible mechanism of action. In conclusion, this study demonstrates that HPO chelators could prove to have therapeutic potential for diseases driven by excessive T cell proliferation.

Anemia and iron deficiency in Crohn's disease

Introduction: Anemia is a common extraintestinal complication of Crohn's disease (CD) mainly caused by iron deficiency, that affects the quality of life in CD patients. Elucidation of the etiology and pathology of iron-deficiency anemia (IDA) and anemia of chronic diseases (ACD) has developed in recent years. Common biochemical parameters of iron status are insufficient for assessment of patients with anemia and CD. Thus, novel iron indices are required for accurate assessment in IDA patients with CD. Oral iron supplementation for IDA treatment is common and is associated with minor gastrointestinal side effects. Intravenous substitution improves safety profiles but may be not tolerable in some patients. Fortunately, additional therapies for anemia of active CD have emerged in recent years.Area covered: Here, we propose the review article on the link among anemia, iron deficiency, and Crohn's disease. We discuss the current diagnosis and therapy of anemia and iron deficiency in CD and propose the new directions for future research.Expert commentary: Exploring pathogeneses and treatments of anemia and iron deficiency in Crohn's disease will develop potential tools for early diagnosis and effective treatment of anemia in CD patients, and improve their life quality.

Associations of Common Variants in HFE and TMPRSS6 Genes with Hepcidin-25 and Iron Status Parameters in Patients with End-Stage Renal Disease

BACKGROUND

Influence of TMPRSS6 A736V and HFE (C282Y and H63D) polymorphisms on serum hepcidin-25 levels and iron status parameters in end-stage renal disease (ESRD) patients stratified according to gender has not been previously investigated. In addition, we aimed to evaluate the diagnostic accuracy of the parameters to separate iron-deficiency anemia (IDA) from anemia of chronic disease.

MATERIALS AND METHODS

Iron status parameters and genetic analysis were performed in 126 ESRD patients and in 31 IDA patients as the control group.

RESULTS

ESRD patients had significantly higher ferritin and hepcidin-25 (<0.001) relative to IDA patients. Cut-off values with the best diagnostic accuracy were found for hepcidin ≥9.32 ng/mL, ferritin ≥48.2 μg/L, transferrin saturation ≥16.8%, and MCV ≥81 fL. Interaction between gender and HFE haplotypes for the hepcidin-25 and ferritin levels in ESRD patients (p = 0.005, partial eta squared = 0.09; p = 0.027, partial eta squared = 0.06, respectively) was found. Serum transferrin was influenced by the combined effect of gender and TMPRSS6 A736V polymorphism in ESRD patients (p = 0.002, partial eta squared = 0.07).

CONCLUSION

Our findings could contribute to the further investigation of mechanisms involved in the pathophysiology and important gender-related involvement of the TMPRSS6 and HFE polymorphisms on anemia in ESRD patients.

Anemia of inflammation

Anemia of inflammation (AI), also known as anemia of chronic disease (ACD), is regarded as the most frequent anemia in hospitalized and chronically ill patients. It is prevalent in patients with diseases that cause prolonged immune activation, including infection, autoimmune diseases, and cancer. More recently, the list has grown to include chronic kidney disease, congestive heart failure, chronic pulmonary diseases, and obesity. Inflammation-inducible cytokines and the master regulator of iron homeostasis, hepcidin, block intestinal iron absorption and cause iron retention in reticuloendothelial cells, resulting in iron-restricted erythropoiesis. In addition, shortened erythrocyte half-life, suppressed erythropoietin response to anemia, and inhibition of erythroid cell differentiation by inflammatory mediators further contribute to AI in a disease-specific pattern. Although the diagnosis of AI is a diagnosis of exclusion and is supported by characteristic alterations in iron homeostasis, hypoferremia, and hyperferritinemia, the diagnosis of AI patients with coexisting iron deficiency is more difficult. In addition to treatment of the disease underlying AI, the combination of iron therapy and erythropoiesis-stimulating agents can improve anemia in many patients. In the future, emerging therapeutics that antagonize hepcidin function and redistribute endogenous iron for erythropoiesis may offer additional options. However, based on experience with anemia treatment in chronic kidney disease, critical illness, and cancer, finding the appropriate indications for the specific treatment of AI will require improved understanding and a balanced consideration of the contribution of anemia to each patient's morbidity and the impact of anemia treatment on the patient's prognosis in a variety of disease settings.

Rational Management of Iron-Deficiency Anaemia in Inflammatory Bowel Disease

Anaemia is the most frequent, though often neglected, comorbidity of inflammatory bowel disease (IBD). Here we want to briefly present (1) the burden of anaemia in IBD, (2) its pathophysiology, which mostly arises from bleeding-associated iron deficiency, followed by (3) diagnostic evaluation of anaemia, (4) a balanced overview of the different modes of iron replacement therapy, (5) evidence for their therapeutic efficacy and subsequently, (6) an updated recommendation for the practical management of anaemia in IBD. Following the introduction of various intravenous iron preparations over the last decade, questions persist about when to use these preparations as opposed to traditional and other novel oral iron therapeutic agents. At present, oral iron therapy is generally preferred for patients with quiescent IBD and mild iron-deficiency anaemia. However, in patients with flaring IBD that hampers intestinal iron absorption and in those with inadequate responses to or side effects with oral preparations, intravenous iron supplementation is the therapy of choice, although information on the efficacy of intravenous iron in patients with active IBD and anaemia is scare. Importantly, anaemia in IBD is often multifactorial and a careful diagnostic workup is mandatory for optimized treatment. Nevertheless, limited information is available on optimal therapeutic start and end points for treatment of anaemia. Of note, neither oral nor intravenous therapies seem to exacerbate the clinical course of IBD. However, additional prospective studies are still warranted to determine the optimal therapy in complex conditions such as IBD.

Management of inflammatory bowel disease-related anemia and iron deficiency with specific reference to the role of intravenous iron in current practice

INTRODUCTION

Anemia is a common extraintestinal manifestation in patients with inflammatory bowel disease, impacting disease prognosis, morbidity, hospitalization rates and time lost from work. While iron deficiency anemia and anemia of chronic inflammation predominate, combinations of hematimetric and biochemical markers facilitate the diagnosis and targeted therapy of other etiologies according to their underlying pathophysiological causes. Intravenous iron replacement is currently recommended in IBD patients with moderate to severe anemia or intolerance to oral iron. Areas covered: This review examines the impact, pathophysiology and diagnostics of iron deficiency and anemia, compares the characteristics and safety profiles of available oral and intravenous iron preparations, and highlights issues which require consideration in decision making for therapy administration and monitoring. Expert opinion: Modern intravenous iron formulations have been shown to be safe and effective in IBD patients, allowing rapid anemia correction and repletion of iron stores. While traditional oral iron preparations are associated with increased inflammation, negative effects on the microbiome, and poor tolerance and compliance, first clinical trial data indicate that newer oral compounds such as ferric maltol and sucrosomial iron offer improved tolerability and may thus offer a viable alternative for the future.

Anemia at the time of diagnosis of inflammatory bowel disease: Prevalence and associated factors in adolescent and adult patients

BACKGROUND

The prevalence, characteristic and determinants of anemia, at the time of inflammatory bowel disease (IBD) diagnosis have yet to be fully elucidated.

METHODS

Retrospective cross-sectional study. Analytical data and disease characteristics obtained upon diagnosis of 1278 IBD patients [Crohn's disease/ulcerative colitis (CD/UC): 718/560] were collected.

RESULTS

Anemia was present in 41.2% of patients at diagnosis (47% and 33.8% of CD and UC patients, respectively; p<0.001), being severe in 5.5%. Iron deficiency anemia represented 69.6% of cases, with no differences between CD and UC. Female sex was the strongest risk factor for anemia in both CD and UC (OR 7.11; 95%CI 4.18-12.10 and 6.55; 95%CI 3.39-12.63, respectively), followed by elevated (≥2mg/dL) C-reactive protein (OR 4.08; 95%CI 2.39-6.97 and 4.58; 95%CI 2.26-9.27, respectively). Current smoking was a risk factor for anemia in CD (OR 2.23; 95%CI 1.24-4.02), but a protective one in UC (OR 0.36; 95%CI 0.14-0.92). A penetrating CD behavior increased the risk of anemia (OR 3.34; 95%CI 1.36-8.21); in UC, anemia increased with disease extension (E2+E3) (OR 1.80; 95%CI 1.13-2.86).

CONCLUSIONS

Female sex and disease activity are major determinants of anemia at IBD diagnosis. Anemia is associated with disease behavior in CD and with disease extension in UC.

Pathobiochemical Mechanisms Relating Iron Homeostasis to Parameters of Inflammatory Activity and Autoimmune Disorders in Rheumatoid Arthritis

Aim: To find the correlations between the parameters of iron homeostasis, inflammatory activity and autoimmune disorders in rheumatoid arthritis (RA).

Materials and methods: The present study included 114 patients with RA and 42 healthy controls. We determined the parameters of iron homeostasis: serum iron, total iron binding capacity (TIBC), ferritin and soluble transferrin receptor (sTfR), the parameters of inflammatory activity: C-reactive protein (CRP), interleukin-6 (IL-6) and prohepcidin, and the parameters of autoimmune disorders: rheumatoid factor (RF), anti-cyclic citrullinated peptide (antiCCP) antibodies, and DAS 28.

Results: The levels of sTfR, CRP, IL-6 and prohepcidin were significantly higher in RA patients than those in the controls and the level of serum iron was significantly lower in RA than that in the control group. Unlike the controls, in RA, there was a significant positive correlation of sTfR with the parameters of inflammatory activity (IL-6, prohepcidin, ESR) and with the parameters of autoimmune disorders (DAS 28, RF, antiCCP). A negative correlation of serum iron with sTfR was found only in RA patients. Prohepcidin positively correlated with the parameters of inflammation (CRP, ESR) and with the parameters for evaluation of autoimmune disorders (DAS 28 and RF) in the RA group.

Conclusion: Our study shows that the simultaneous determination of the two parameters sTfR and prohepcidin is most informative in evaluating the changes in iron homeostasis in RA. The increase of both parameters provides information for tissue iron deficiency (assessed by the level of sTfR), caused by the inflammation when prohepcidin is expressed.

Iron Deficiency Anemia Coexists with Cancer Related Anemia and Adversely Impacts Quality of Life

Cancer related anemia (CRA) adversely affects patient Quality of Life (QoL) and overall survival. We prospectively studied the prevalence, etiology and the impact of anemia on QoL in 218 Indian cancer patients attending a tertiary referral hospital. The study used the sTfR/log Ferritin index to detect iron deficiency anemia and assessed patient QoL using the Functional Assessment of Cancer Therapy-Anemia (FACT-An) tool, standardized for language. Mean patient age was 51±13 years and 60% were female. The prevalence of cancer related anemia in this setting was 64% (n = 139). As expected, plasma ferritin did not differ significantly between anemic (n = 121) and non-anemic cancer patients (n = 73). In contrast, plasma sTfR levels were significantly higher in anemic cancer patients compared to non-anemic cancer patients (31 nmol/L vs. 24 nmol/L, p = 0.002). Among anemic cancer patients, using the sTfR/log Ferritin index, we found that 60% (n = 83) had iron deficiency anemia (IDA). Interestingly, plasma sTfR levels were significantly higher in cancer patients with CRA+IDA (n = 83) compared with patients having CRA (n = 38) alone (39 nmol/L vs. 20 nmol/L, p<0.001). There was a significant linear correlation between Hb and QoL (Spearman ρ = 0.21; p = 0.001) and multivariate regression analysis revealed that every gram rise in Hb was accompanied by a 3.1 unit increase in the QoL score (95% CI = 0.19–5.33; p = 0.003). The high prevalence of anemia in cancer patients, a major portion of which is due to iron deficiency anemia, the availability of sensitive and specific biomarkers of iron status to detect IDA superimposed on anemia of inflammation, suggests an urgent need to diagnose and treat such patients. Despite the potential negative consequences of increasing metabolically available plasma iron in cancer, our clinical data suggest that detecting and treating IDA in anemic cancer patients will have important consequences to their QoL and overall survival. Clinical trials of iron therapy in these patients will be able to demonstrate the potential for benefit or harm.

Iron replacement therapy: do we need new guidelines?

PURPOSE OF REVIEW

Approximately, one-third of the world's population suffers from anemia, and at least half of these cases are because of iron deficiency. With the introduction of new intravenous iron preparations over the last decade, uncertainty has arisen when these compounds should be administered and under which circumstances oral therapy is still an appropriate and effective treatment.

RECENT FINDINGS

Numerous guidelines are available, but none go into detail about therapeutic start and end points or how iron-deficiency anemia should be best treated depending on the underlying cause of iron deficiency or in regard to concomitant underlying or additional diseases.

SUMMARY

The study points to major issues to be considered in revisions of future guidelines for the true optimal iron replacement therapy, including how to assess the need for treatment, when to start and when to stop treatment, when to follow-up for relapse, which dosage and type of therapy should be recommended or not recommended, and if some patients should not be treated.

The Iron age of host-microbe interactions

Microbes exert a major impact on human health and disease by either promoting or disrupting homeostasis, in the latter instance leading to the development of infectious diseases. Such disparate outcomes are driven by the ever-evolving genetic diversity of microbes and the countervailing host responses that minimize their pathogenic impact. Host defense strategies that limit microbial pathogenicity include resistance mechanisms that exert a negative impact on microbes, and disease tolerance mechanisms that sustain host homeostasis without interfering directly with microbes. While genetically distinct, these host defense strategies are functionally integrated, via mechanisms that remain incompletely defined. Here, we explore the general principles via which host adaptive responses regulating iron (Fe) metabolism impact on resistance and disease tolerance to infection.

Anaemia in the Elderly IBD Patient

OPINION STATEMENT

Anaemia is a common multifactorial extraintestinal manifestation in IBD patients. Moreover, anaemia represents an important health problem among the elderly population and has a significant impact on healthcare utilisation and costs. Data on the prevalence, diagnosis and management of anaemia in elderly IBD patients are scarce, since clinical trials have largely excluded this population. In this review, we reconsider anaemia in older IBD patients in the light of new diagnostic and therapeutic tools.

Anemia of Chronic Disorders: New Diagnostic Tools and New Treatment Strategies

Anemia in the setting of chronic inflammatory disorders is a very frequent clinical condition, which is, however, often neglected or not properly treated given the problems often caused by the diseases underlying the development of anemia. Mechanistically, anemia is mainly caused by inflammation-driven retention of iron in macrophages making the metal unavailable for heme synthesis in the course of erythropoiesis, and further by impaired biological activity of the red blood cell hormone erythropoietin and the reduced proliferative capacity of erythroid progenitor cells. Anemia can be aggravated by chronic blood loss, as found in subjects with gastrointestinal cancers, inflammatory or infectious bowel disease, or iatrogenic blood loss in the setting of dialysis, all resulting in true iron deficiency. The identification of such patients is a clinical necessity because these individuals need contrasting therapies in comparison to subjects suffering from only classical anemia of chronic disorders. The diagnosis is challenging because no state of the art laboratory test is currently available that can clearly separate patients with inflammatory anemia from those with additional true iron deficiency. However, based on our expanding knowledge on the pathophysiology of inflammatory anemia, new diagnostic markers, including the iron-regulatory hormone hepcidin, and hematologic parameters emerge. Apart from traditional anemia treatments such as blood transfusions, recombinant erythropoietin, and iron, including new high-molecular-weight formulations, new therapeutics are currently under preclinical and clinical evaluation. These novel compounds aim at correcting anemia by multiple pathways, including antagonizing the inflammation- and hepcidin-driven retention of iron in the monocyte-macrophage system and thereby promoting the supply of iron for erythropoiesis or by stimulating the endogenous formation of erythopoietin via stabilization of hypoxia-regulated factors.

Management of Iron-Deficiency Anemia in Inflammatory Bowel Disease: A Systematic Review

Anemia is the most frequent complication of inflammatory bowel disease (IBD), but anemia, mostly due to iron deficiency, has long been neglected in these patients. The aim was to briefly present the pathophysiology, followed by a balanced overview of the different forms of iron replacement available, and subsequently, to perform a systematic review of studies performed in the last decade on the treatment of iron-deficiency anemia in IBD. Given that intravenous therapies have been introduced in the last decade, a systematic review performed in PubMed, EMBASE, the Cochrane Library, and the websites of WHO, FDA, and EMA covered prospective trials investigating the management of iron-deficiency anemia in IBD published since 2004. A total of 632 articles were reviewed, and 13 articles (2906 patients) with unique content were included. In general, oral supplementation in iron-deficiency anemia should be administered with a target to restore/replenish the iron stores and the hemoglobin level in a suitable way. However, in patients with IBD flares and inadequate responses to or side effects with oral preparations, intravenous iron supplementation is the therapy of choice. Neither oral nor intravenous therapy seems to exacerbate the clinical course of IBD, and intravenous iron therapy can be administered even in active disease stages and concomitantly with biologics. In conclusion, because many physicians are in doubt as to how to manage anemia and iron deficiency in IBD, there is a clear need for the implementation of evidence-based recommendations on this matter. Based on the data presented, oral iron therapy should be preferred for patients with quiescent disease stages and trivial iron deficiency anemia unless such patients are intolerant or have an inadequate response, whereas intravenous iron supplementation may be of advantage in patients with aggravated anemia or flares of IBD because inflammation hampers intestinal absorption of iron.

Evaluation of erythrocyte and reticulocyte parameters as indicative of iron deficiency in patients with anemia of chronic disease

Objective

The aim of this study was to evaluate the effectiveness of mature red cell and reticulocyte parameters to identify three conditions: iron deficiency anemia, anemia of chronic disease, and anemia of chronic disease associated with absolute iron deficiency.

Methods

Peripheral blood cells from 117 adult patients with anemia were classified according to iron status, inflammation, and hemoglobinopathies as: iron deficiency anemia (n = 42), anemia of chronic disease (n = 28), anemia of chronic disease associated with iron deficiency anemia (n = 22), and heterozygous β-thalassemia (n = 25). The percentage of microcytic erythrocytes, hypochromic erythrocytes, and the levels of hemoglobin in both reticulocytes and mature red cells were determined. Receiver operating characteristic analysis was used to evaluate the accuracy of the parameters in differentiating anemia.

Results

There was no difference between the groups of iron deficiency and anemia of chronic disease associated with absolute iron deficiency for any of the parameters. The percentage of hypochromic erythrocytes was the best parameter to identify absolute iron deficiency in patients with anemia of chronic disease (area under curve = 0.785; 95% confidence interval: 0.661–0.909 with sensitivity of 72.7%, and specificity of 70.4%; cut-off value 1.8%). The formula microcytic erythrocyte count minus hypochromic erythrocyte count was very accurate to differentiate iron deficiency anemia from heterozygous β-thalassemia (area under curve = 0.977; 95% confidence interval: 0.950–1.005 with a sensitivity of 96.2%, and specificity of 92.7%; cut-off value 13.8).

Conclusion

The erythrocyte and reticulocyte indices are moderately good to identify absolute iron deficiency in patients with anemia of chronic disease.

Iron supplementation and mortality in incident dialysis patients: an observational study

BACKGROUND

Studies on the association between iron supplementation and mortality in dialysis patients are rare and conflicting.

METHODS

In our observational single-center cohort study (INVOR study) we prospectively studied 235 incident dialysis patients. Time-dependent Cox proportional hazards models using all measured laboratory values for up to 7.6 years were applied to study the association between iron supplementation and all-cause mortality, cardiovascular and sepsis-related mortality. Furthermore, the time-dependent association of ferritin levels with mortality in patients with normal C-reactive protein (CRP) levels (<0.5 mg/dL) and elevated CRP levels (≧0.5 mg/dL) was evaluated by using non-linear P-splines to allow flexible modeling of the association.

RESULTS

One hundred and ninety-one (81.3%) patients received intravenous iron, 13 (5.5%) patients oral iron, whereas 31 (13.2%) patients were never supplemented with iron throughout the observation period. Eighty-two (35%) patients died during a median follow-up of 34 months, 38 patients due to cardiovascular events and 21 patients from sepsis. Baseline CRP levels were not different between patients with and without iron supplementation. However, baseline serum ferritin levels were lower in patients receiving iron during follow up (median 93 vs 251 ng/mL, p<0.001). Iron supplementation was associated with a significantly reduced all-cause mortality [HR (95%CI): 0.22 (0.08-0.58); p = 0.002] and a reduced cardiovascular and sepsis-related mortality [HR (95%CI): 0.31 (0.09-1.04); p = 0.06]. Increasing ferritin concentrations in patients with normal CRP were associated with a decreasing mortality, whereas in patients with elevated CRP values ferritin levels>800 ng/mL were linked with increased mortality.

CONCLUSIONS

Iron supplementation is associated with reduced all-cause mortality in incident dialysis patients. While serum ferritin levels up to 800 ng/mL appear to be safe, higher ferritin levels are associated with increased mortality in the setting of concomitant inflammation.

Current practice in the diagnosis and management of IBD-associated anaemia and iron deficiency in Germany: the German AnaemIBD Study

BACKGROUND/AIM

Anaemia is a common complication in inflammatory bowel disease (IBD), frequently resulting from iron deficiency. IBD guidelines advocate intravenous iron administration although some patients respond to oral supplementation. This non-interventional study investigates the current status of anaemia management in German IBD patients.

METHODS

Baseline data on pre-study treatment for anaemia were retrospectively analysed in IBD patients with anaemia participating in a prospective trial of the efficacy and safety of ferric carboxymaltose. Data were collected from 55 German gastroenterological centres up to August 2010. Subjects had received care at their centre for at least 12 months prior to baseline.

RESULTS

193 cases of IBD-associated anaemia (115 Crohn's disease, 77 ulcerative colitis) were analysed (mean age: 39 years (18-83), 79 (41%) males). Anaemia and iron status were usually assessed by haemoglobin (100%), serum ferritin (97%), and transferrin saturation (82%). In the previous 6 months, only 84 patients (43.5%) had been treated for anaemia: 47 (56%) with oral iron, 13 (15%) parenteral iron, 16 (19%) oral plus parenteral iron and 8 (10%) transfusions. No patients received erythropoietin stimulating agents.

CONCLUSION

Although intravenous iron supplementation is recommended in IBD patients, current German practice still relies on oral therapy, even in severe anaemia. The high incidence of severe anaemia in this cohort reflects inadequate iron replacement and status monitoring. While the proportion of IBD patients with inadequately treated anaemia/iron deficiency is unknown, greater awareness of existing guidelines for iron deficiency management in IBD patients appears necessary.

Evaluation of red cell and reticulocyte parameters as indicative of iron deficiency in patients with anemia of chronic disease

OBJECTIVE

The purpose of this study was to evaluate the effectiveness of mature red cell and reticulocyte parameters under three conditions: iron deficiency anemia, anemia of chronic disease, and anemia of chronic disease associated with absolute iron deficiency.

METHODS

Peripheral blood cells from 117 adult patients with anemia were classified according to iron status, and inflammatory activity, and the results of a hemoglobinopathy investigation as: iron deficiency anemia (n=42), anemia of chronic disease (n=28), anemia of chronic disease associated with iron deficiency anemia (n=22), and heterozygous β thalassemia (n=25). The percentage of microcytic red cells, hypochromic red cells, and levels of hemoglobin content in both reticulocytes and mature red cells were determined. Receiver operating characteristic analysis was used to evaluate the accuracy of the parameters in differentiating between the different types of anemia.

RESULTS

There was no significant difference between the iron deficient group and anemia of chronic disease associated with absolute iron deficiency in respect to any parameter. The percentage of hypochromic red cells was the best parameter to discriminate anemia of chronic disease with and without absolute iron deficiency (area under curve=0.785; 95% confidence interval: 0.661-0.909, with sensitivity of 72.7%, and specificity of 70.4%; cut-off value 1.8%). The formula microcytic red cells minus hypochromic red cells was very accurate in differentiating iron deficiency anemia and heterozygous β thalassemia (area under curve=0.977; 95% confidence interval: 0.950-1.005; with sensitivity of 96.2%, and specificity of 92.7%; cut-off value 13.8).

CONCLUSION

The indices related to red cells and reticulocytes have a moderate performance in identifying absolute iron deficiency in patients with anemia of chronic disease.

Iron at the interface of immunity and infection

Both, mammalian cells and microbes have an essential need for iron, which is required for many metabolic processes and for microbial pathogenicity. In addition, cross-regulatory interactions between iron homeostasis and immune function are evident. Cytokines and the acute phase protein hepcidin affect iron homeostasis leading to the retention of the metal within macrophages and hypoferremia. This is considered to result from a defense mechanism of the body to limit the availability of iron for extracellular pathogens while on the other hand the reduction of circulating iron results in the development of anemia of inflammation. Opposite, iron and the erythropoiesis inducing hormone erythropoietin affect innate immune responses by influencing interferon-gamma (IFN-γ) mediated (iron) or NF-kB inducible (erythropoietin) immune effector pathways in macrophages. Thus, macrophages loaded with iron lose their ability to kill intracellular pathogens via IFN-γ mediated effector pathways such as nitric oxide (NO) formation. Accordingly, macrophages invaded by the intracellular bacterium Salmonella enterica serovar Typhimurium increase the expression of the iron export protein ferroportin thereby reducing the availability of iron for intramacrophage bacteria while on the other side strengthening anti-microbial macrophage effector pathways via increased formation of NO or TNF-α. In addition, certain innate resistance genes such as natural resistance associated macrophage protein function (Nramp1) or lipocalin-2 exert part of their antimicrobial activity by controlling host and/or microbial iron homeostasis. Consequently, pharmacological or dietary modification of cellular iron trafficking enhances host resistance to intracellular pathogens but may increase susceptibility to microbes in the extracellular compartment and vice versa. Thus, the control over iron homeostasis is a central battlefield in host–pathogen interplay influencing the course of an infectious disease in favor of either the mammalian host or the pathogenic invader.

Blood cadmium is elevated in iron deficient U.S. children: a cross-sectional study

BACKGROUND

Cadmium (Cd), a widespread environmental contaminant, and iron deficiency (ID), the most common nutrient deficiency in the world, are known risk factors for neurodevelopmental delays, as well as other disorders, in infants and children. Studies assessing the cumulative effects of these factors are lacking in children, despite concerns of increased uptake of metals in the presence of ID. Here we sought to determine if blood and urine Cd levels were elevated in ID children compared to non-ID children.

METHODS

Data for 5224 children, aged 3-19 years, were obtained from the 1999-2002 NHANES. ID was defined as ≥2 of 3 abnormal iron indicators (low serum ferritin [SF], high free erythrocyte protoporphyrin [FEP], low % transferrin saturation [TSAT]); ID anemia (IDA) was defined as ID plus low hemoglobin (Hgb). Logistic regression was used to evaluate associations between ID, IDA, and abnormal iron indicators and categories of blood and urine Cd.

RESULTS

Adjusted odds of ID, IDA, low SF, and low TSAT were associated with increasing category of blood Cd but not urine Cd. Adjusted ORs (95% CI) for blood Cd ≥0.5 μg/L versus < LOD were = 1.74 (1.30-2.34), 4.02 (1.92-8.41), 4.08 (2.36-5.89) and 1.78 (1.32-2.39), for ID, IDA, low SF, and low TSAT, respectively. Age and sex specific analyses of blood Cd and ID/abnormal iron indicators revealed that the observed associations were strongest in females aged 16-19 years.

CONCLUSIONS

Given their shared neurotoxic effects in children, and that many people live in areas with high burdens of both ID and Cd, more research into the complex relationships between nutrient deficiencies and environmental toxicants is vital.

The impact of an algorithm-guided management of preoperative anemia in perioperative hemoglobin level and transfusion of major orthopedic surgery patients

The aim of this study was to evaluate a laboratory-guided therapeutic algorithm of preoperative anemia. 335 patients with elective hip or knee arthroplasty were included in this retrospective before-after study. Group I (n = 101) underwent conventional preoperative procedures before algorithm implementation. Group II (n = 234) underwent algorithm-guided preoperative anemia management. A hemoglobin-level of 13 g/dL was the therapeutic cut-off for men and women. Reticulocyte hemoglobin content (CHr) and soluble transferrin receptor (sTfR)/log ferritin ratio were used in the form of the Thomas plot. Iron deficiency (ID) was substituted with 1000 mg iron intravenous (i.v.) and 10000 international units (I.U.) of erythropoiesis-stimulating agent (ESA) subcutaneous (s.c.) or i.v., anemia of chronic disease (ACD) (without functional ID) with 40000 I.U. ESA s.c. or i.v and additionally 200 mg iron i.v. Substituted anemic patients in Group II (n = 32) showed a distinctly higher preoperative (Hb-median 13 versus 11.95 g/dL) (P < 0.01) and postoperative (Hb-median 9.75 versus 9.0 g/dL) (P < 0.05) Hb level compared with untreated anemic patients in Group I (n = 24). In Group II red blood cell (RBC) units (35 units/234 patients) were reduced by 44% compared with Group I (27 units/101 patients). Algorithm-guided preoperative anemia management raises perioperative Hb-level and reduces blood use.

Anemia treatment of lymphoproliferative malignancies with erypoiesis: an overview of state of the art

Anemia is a common comorbidity of lymphoproliferative malignancies, especially in multiple myeloma. Blood transfusions and ESAs (erythropoiesis stimulating agents) are both possible treatment options, but the latter is often preferred because of the potential risks of unwanted side effects related to blood transfusions. Evidence is accumulating that the use of ESAs in above clinical conditions is safe and effective and not associated with an increase in mortality or serious adverse events. 69.1% of patients achieved a hemoglobin response defined as an increase in hemoglobin of>2g/dl while receiving ESAs and concomitant chemotherapy. If supplemented with iron the hemoglobin response rate can be increased and hence the total dosage and financial cost reduced. A hemoglobin response is often accompanied by an increase in quality of life. HYPO% (hypochromic erythrocytes<5%) is believed to be both a significant positive predictor for the Hb response and also an indicator for iron supplementation if⩾5%. Conventional biochemical markers like serum ferritin concentration and transferrin saturation are not reliable for this use. The effect of EPO stimulating agents as the predictor of the Hb response, quality of life, mortality and the potential adverse events are discussed.

Current status of pharmacologic therapies in patient blood management

Patient blood management(1,2) incorporates patient-centered, evidence-based medical and surgical approaches to improve patient outcomes by relying on the patient's own (autologous) blood rather than allogeneic blood. Particular attention is paid to preemptive measures such as anemia management. The emphasis on the approaches being "patient-centered" is to distinguish them from previous approaches in transfusion medicine, which have been "product-centered" and focused on blood risks, costs, and inventory concerns rather than on patient outcomes. Patient blood management(3) structures its goals by avoiding blood transfusion(4) with effective use of alternatives to allogeneic blood transfusion.(5) These alternatives include autologous blood procurement, preoperative autologous blood donation, acute normovolemic hemodilution, and intra/postoperative red blood cell (RBC) salvage and reinfusion. Reviewed here are the available pharmacologic tools for anemia and blood management: erythropoiesis-stimulating agents (ESAs), iron therapy, hemostatic agents, and potentially, artificial oxygen carriers.

Anaemia in inflammatory rheumatic diseases

Anaemia is frequently observed in patients with inflammatory rheumatic diseases. Depending on its severity, anaemia negatively affects cardiovascular performance, physical activity and the quality of life of patients. However, anaemia is considered to be a symptom of the underlying inflammatory disease and, thus, neglected as a complex medical condition that warrants specific diagnosis and treatment. Although inflammation-induced alterations in iron homeostasis and erythropoiesis have a dominant role in the pathogenesis of this type of anaemia, multiple other factors such as chronic blood loss, haemolysis, disease and treatment-associated adverse effects or vitamin deficiencies can also take part in the development of anaemia. Accordingly, the prevalence of anaemia is positively associated with the severity of the underlying disease. This Review will summarize epidemiological data on anaemia in inflammatory rheumatic diseases, along with a detailed description of underlying pathophysiological pathways, available diagnostic tools and practical diagnostic strategies. Discussion of established and newly emerging treatment regimens, as well as the need for further research in this clinically relevant field, will also be included.

Diagnosis of anaemia: old things rearranged

Anaemia is one of the most leading causes of morbidity and mortality, as declared by the World Health Organisation. This syndrome is characterised by low haemoglobin levels and nonspecific clinical symptoms such as weakness, fatigue and dyspnoea. The symptoms are unspecific as the underlying causes are heterogeneous. Thus, good knowledge of the useful biomarkers and their correct assignment is needed to allow rapid and targeted diagnosis.

Transient impairment of reticulocyte hemoglobin content and hepcidin-25 induction in patients with community-acquired pneumonia

INTRODUCTION

Patients with community-acquired pneumonia (CAP) often exhibit a declining hemoglobin (Hb) concentration. During inflammation pro-inflammatory cytokines and cells of the reticuloendothelial system induce disturbances in iron homeostasis. In this study inflammation markers and hepcidin-25 concentrations were monitored together with short-term alterations in reticulocyte hemoglobinization (RET-He).

METHODS

A total of 25 patients with CAP participated in the study. The assay for serum hepcidin-25 is based on a combination of weak cation exchange chromatography and time-of-flight mass spectrometry.

RESULTS

At hospital admission serum hepcidin-25 concentrations (14.6 ± 6.9 nMol/L, mean ± SD) were established in the upper level of the reference range (0.5-13.9 nMol/L). Results for C-reactive protein (CRP) and Interleukin-6 (IL-6) were obviously increased compared to the reference ranges. From admission until day 14 hepcidin-25, CRP and IL-6 steadily decreased towards the reference ranges. Hb concentrations declined from admission until day 4 from 8.1 ± 1.0 mMol/L to 7.4 ± 0.9 mMol/L. At admission Ret-He results were within the lower region of the reference range (1900-2300aMol) and results demonstrated a decline during admission from 1931 ± 241 aMol until 1845 ± 199 aMol (NS) at day 4. From a minimum Ret-He value at day 4 results increased towards 2129 ± 136 aMol at day14.

CONCLUSION

A transient increase of cytokine-stimulated serum hepcidin-25 in combination with a temporary decrease of Hb and Ret-He is demonstrated in patients with CAP. Our results support the hypothesis that hepcidin-25 induces transient impairment of reticulocyte hemoglobin content (Ret-He).

Temporary impairment of reticulocyte haemoglobin content in subjects with community-acquired pneumonia

INTRODUCTION

In the case of inflammation, imbalance of iron homoeostasis is caused by increased retention of iron within cells of the reticuloendothelial system. Iron-restricted erythropoiesis occurs because of decreased availability of iron for haemoglobin (Hb) synthesis in erythroid progenitor cells. Deviations in reticulocyte haemoglobin (Ret-He) content are investigated together with inflammation markers in subjects with community-acquired pneumonia (CAP). Short-term alterations with regard to Ret-He during and after completing antibiotic treatment are investigated.

METHODS

A total of 75 patients, classified into three subgroups with CURB-65 scores of ≤1, 2 and ≥3, participated in the study.

RESULTS

Within the three subgroups, Hb results demonstrate a decline from the day of admission until day 4. From day 4, an increase towards higher values is observed at day 14. Within 24 h after admission, Ret-He results are situated within the lower quartile region of the reference range interval. Until day 4 of hospital admission, a steady trend towards a decline of 3-8% is established. During antibiotic treatment, an increase in reticulocyte count occurs from 0.039 ± 0.014 × 10(12) /L at day 4 to 0.057 ± 0.020 × 10(12) /L at day 14 (mean ± SD). Recovery of Hb and Ret-He occurs towards values within the reference range.

CONCLUSION

In subjects with CAP, acute inflammation results in impairment of Ret-He at an early stage. After onset of pneumonia, decreased results of Ret-He and Ret-He/RBC-He ratio are demonstrated, reflecting acute erythropoietic dysfunction, which are amongst others caused by functional iron depletion.

Hepcidin in anemia of chronic kidney disease: review for the pediatric nephrologist

Anemia coincident with hyporesponsiveness to erythropoiesis-stimulating agents is an ongoing and prevalent problem in children with chronic kidney disease (CKD). The recently identified iron-regulatory protein hepcidin appears likely to play a significant role in this problem. Hepcidin up-regulation in the setting of CKD, with subsequent increased serum levels, results in impaired iron absorption from the intestine and decreased iron release from body storage sites. Ultimately, in the setting of such elevated levels, a state of functional iron deficiency may develop and lead to anemia due to iron-restricted erythropoiesis. Elevated hepcidin levels are expected in the face of decreased glomerular filtration rate and inflammation. Based on current evidence, it seems likely that hepcidin represents a potentially modifiable mediator of anemia of CKD and is thus a potential target for future anemia therapy. Currently, increased removal via intensified dialysis and-/or blockade of the inflammatory pathway appear to be two viable generic strategies for reducing hepcidin levels. Goals of directly manipulating the hepcidin pathway should offer the pediatric clinician new options for treating the complex anemia associated with CKD.

Serum hepcidin-25 in comparison to biochemical markers and hematological indices for the differentiation of iron-restricted erythropoiesis

BACKGROUND

Biochemical markers have problems in distinguishing iron deficiency anemia (IDA) from anemia of chronic disease (ACD), and the combined state of iron-restricted erythropoiesis (IRE) with ACD (ACD/IRE). We investigated the extent to which hepcidin-25, a potential marker for the evaluation of iron metabolism, enables the differentiation of the states above, and to assess its correlation with convential markers of iron deficiency.

METHODS

One hundred and fifty-five patients with anemia were classified as having IDA, ACD or ACD/IRE using clinical findings, biochemical markers and hematological indices. The diagnostic performance of hepcidin-25 alone or in combination with the reticulocyte hemoglobin content (CHr) was evaluated using receiver-operating characteristic curve analysis and multivariate analysis. Hepcidin-25 was determined using an isotope-dilution micro-HPLC-tandem mass spectrometry method.

RESULTS

Hepcidin-25 correlated with biochemical markers of iron deficiency but not with hematological indices. Use of a hepcidin-25 cut-off of ≤ 4 nmol/L allowed the differentiation of IDA from ACD and ACD/IRE, but not the discrimination of ACD from ACD/IRE in patients with severe inflammation. Furthermore, the discrimination of ACD/IRE from ACD required the combination with CHr.

CONCLUSIONS

Hepcidin-25 is primarily an indicator for decreased body iron levels, but not for IRE. The combination of hepcidin-25 with CHr in a diagnostic plot (hepcidin-25 plot) might be useful for the differentiation of ACD from ACD/IRE and IDA.

Detection, evaluation, and management of iron-restricted erythropoiesis

Progress in our understanding of iron-restricted erythropoiesis has been made possible by important advances in defining the molecular mechanisms of iron homeostasis. The detection and diagnostic classification of iron-restricted erythropoiesis can be a challenging process for the clinician. Newer assays for markers of inflammation may allow more targeted management of the anemia in these conditions. The availability of new intravenous iron preparations provides new options for the treatment of iron-restricted erythropoiesis. This review summarizes recent advances regarding the detection, evaluation, and management of iron-restricted erythropoiesis.

A new concept for the differential diagnosis and therapy of anaemia in cancer patients

PURPOSE

This study aimed to prove the usefulness of the diagnostic plot, using the haemoglobin content of reticulocytes as a measure of functional iron deficiency (FID) and the ferritin index as a measure of iron availability, to customise anaemia treatment in cancer patients.

METHODS

Based on results of this plot, cancer patients fulfilling practice guideline criteria to receive erythropoiesis-stimulating agents (ESAs) were allocated to treatment with ESAs alone, iron alone or the combination of both. Primary endpoint was the percentage of patients identified to require iron in addition or as an alternative to ESA therapy.

RESULTS

Out of 303 patients screened, 286 were allocated to treatment: 204 patients were normochromic and iron replete and treated with ESAs alone, 22 had both FID and anaemia of chronic disease and were treated with ESAs and parenteral iron, and 60 were iron-depleted and treated with iron only. After 8 weeks, a haemoglobin increase >1 g/dL from baseline was shown by 56% of patients treated with ESAs alone, by 100% of patients receiving the combination, by 50% of normochromic and by 73% of hypochromic iron-depleted patients receiving iron only. Acute phase reaction did not diminish the response rate to ESAs.

CONCLUSIONS

The diagnostic plot was superior to transferrin saturation and ferritin in predicting iron availability in hypochromic patients treated with ESAs and proved useful to select treatment for anaemia in cancer patients.

Randomized clinical trial of preoperative intravenous iron sucrose to reduce blood transfusion in anaemic patients after colorectal cancer surgery

BACKGROUND

The transfusion rate following colorectal cancer resection is between 10 and 30 per cent. Receipt of allogeneic blood is not without risk or cost. A preoperative adjunct that reduced the need for transfusion would mitigate these risks. This study was designed to determine whether iron sucrose reduces the likelihood of postoperative blood transfusion in patients undergoing elective colorectal cancer resection.

METHODS

In this randomized prospective blinded placebo-controlled trial of patients undergoing resectional surgery with a preoperative diagnosis of colorectal cancer, 600 mg iron sucrose or placebo was given intravenously in two divided doses, at least 24 h apart, 14 days before surgery. The primary outcome measures were serum haemoglobin concentration, recorded at recruitment, immediately before surgery and at discharge, and perioperative blood transfusions.

RESULTS

No difference was demonstrated between treatment groups (iron sucrose, 34 patients; placebo, 26) for any of the primary outcome measures, for either the whole study population or a subgroup of anaemic patients.

CONCLUSION

This pilot study provided no support for the use of intravenous iron sucrose as a preoperative adjunct to increase preoperative haemoglobin levels and thereby reduce the likelihood of allogeneic blood transfusion for patients undergoing resectional surgery for colorectal cancer.

REGISTRATION NUMBER

2005-003608-13UK (Medicines and Healthcare products Regulatory Agency).

Growth differentiation factor 15 in anaemia of chronic disease, iron deficiency anaemia and mixed type anaemia

Recently, the iron and erythropoiesis-controlled growth differentiation factor 15 (GDF15) has been shown to inhibit the expression of hepcidin in beta-thalassaemia patients, thereby increasing iron absorption despite iron overload. To access the diagnostic and pathogenic impact of GDF15 in inflammatory anaemia the association of GDF15 expression with serum iron parameters and hepcidin was studied in patients suffering from iron deficiency anaemia (IDA), anaemia of chronic disease (ACD) and ACD subjects with true iron deficiency (ACD/IDA). GDF15 was significantly increased in both ACD and ACD/IDA, but not in IDA subjects as compared to controls. In contrast, hepcidin levels were significantly lower in IDA and ACD/IDA subjects than in ACD patients. IDA and ACD/IDA, but not ACD, showed an association between GDF15 and soluble transferrin receptor, an indicator of iron requirement for erythropoiesis. However, GDF15 did not correlate to hepcidin in either patient group. While GDF15 levels were linked to the needs for erythropoiesis and iron homeostasis in IDA, the immunity-driven increase of GDF15 may not primarily affect iron homeostasis and hepcidin expression. This indicates that other ACD-related factors may overcome the regulatory effects of GDF15 on hepcidin expression during inflammation.

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.

Iron-refractory iron deficiency anemia: new molecular mechanisms

Iron deficiency anemia is a common complication in end-stage renal disease (ESRD) and impairs the therapeutic efficacy of recombinant erythropoietin. Oral or parental iron supplements usually are effective in treating iron deficiency anemia. Some patients, however, respond poorly to iron supplements and are diagnosed as having iron-refractory iron deficiency anemia. The condition exacerbates ESRD but its underlying mechanism was unclear. Hepcidin is a central player in iron homeostasis. It downregulates the iron exporter ferroportin, thereby inhibiting iron absorption, release, and recycling. In ESRD, plasma hepcidin levels are elevated, which contributes to iron deficiency in patients. Matriptase-2, a liver transmembrane serine protease, has been found to have a major role in controlling hepcidin gene expression. In mice, defects in the Tmprss6 gene encoding matriptase-2 result in high hepcidin expression and cause severe microcytic anemia. Similarly, mutations in the human TMPRSS6 gene have been identified in patients with iron-refractory iron deficiency. Thus, matriptase-2 is critical for iron homeostasis and may have an important role in ESRD.