Anaemia of chronic disease

An Introduction to the Complete Blood Count for Clinical Chemists: Red Blood Cells

BACKGROUND

The most frequently ordered laboratory test worldwide is the complete blood count (CBC).

CONTENT

In this primer, the red blood cell test components of the CBC are introduced, followed by a discussion of the laboratory evaluation of anemia and polycythemia.

SUMMARY

As clinical chemists are increasingly tasked to direct laboratories outside of the traditional clinical chemistry sections such as hematology, expertise must be developed. This review article is a dedication to that effort.

Iron Status and Physical Performance in Athletes

Iron is an important mineral in the body, essential for muscle function and oxygen transport. Adequate levels of iron in the blood are necessary for athletes, as iron-deficiency anemia can reduce physical performance. Several studies have investigated iron status and supplementation in iron-deficient athletes, and determined how physical strain can change iron balance and markers related to iron status. The question of how to influence and optimize iron status, as well as other markers that can affect iron metabolism, has been less thoroughly investigated. Therefore, the aim of this review is to take a closer look at the importance of iron values, iron markers, and factors that can change iron metabolism for physical performance and the extent to which physical performance can be influenced in a positive or negative way. A systematic search of the PubMed database was performed, with the use of « iron» or «iron deficiency» or «hemoglobin» AND «athletes» AND «athletic performance» as a strategy of the search. After the search, 11 articles were included in the review after the application of inclusion and exclusion criteria. Major findings include that iron supplementation had the best effect in athletes with the lowest iron status, and effects on physical performance were mostly achieved in those who were originally in a deficit. Iron supplementation could be beneficial for optimal erythropoietic response during altitude training, even in athletes with normal iron stores at baseline, but should be performed with caution. Alteration of the hepcidin response can affect the use of existing iron stores for erythropoiesis. Energy intake, and the amount of carbohydrates available, may have an impact on the post-exercise hepcidin response. Optimal vitamin D and B12 levels can possibly contribute to improved iron status and, hence, the avoidance of anemia.

Anemia in early congenital syphilis

The determination of blood parameters allowed us to establish that anemia develops in a number of infectious diseases, which is called "anemia of inflammation" or anemia of chronic diseases. The article presents a rare clinical case of the development of anemia of the inflammatory response, accompanied by a marked decrease in the content of hemoglobin (less than 110 g/l), hematocrit (less than 30%) and red blood cells (less than 3,0 х 1012/l), in a child with early congenital syphilis with symptoms of: specific rhinitis, papular infiltration, pemphigus, hepatosplenomegaly and damage to the nervous system. As a result of specific treatment with water-soluble benzylpenicillin salt at the rate of 100 U/kg of body weight for 28 days, and transfusion of erythrocyte mass of 15 ml/kg of child weight, there was a parallel regression of clinical manifestations of syphilis with positive dynamics of serological reactions and restoration of the number of red blood cells and the concentration of hemoglobin in the blood.

Hematological involvement in pediatric systemic lupus erythematosus: A multi-center study

Introduction: Systemic lupus erythematosus (SLE) may present with features of several systems, including hematological manifestations. In this study, we aimed to evaluate the characteristics of hematological involvement and assess possible associations and correlations in pediatric SLE patients. Method: This is a retrospective multi-center study. The medical records of pediatric SLE patients followed between January 2000 and June 2020 were analyzed. All children fulfilled the criteria of the Systemic Lupus International Collaborating Clinics. Results: The study included 215 children with SLE, 118 of whom had hematological manifestations. Concomitant renal involvement and low C3 levels were significantly more frequent in patients with hematological involvement (p = 0.04, p = 0.008, respectively). Also, anti-cardiolipin, anti-beta-2-glycoprotein I (anti-β2 GP1), and anti-Sm antibody positivity, and the presence of lupus anticoagulant were more common in the group with hematological findings (p = 0.001 for anti-cardiolipin antibody positivity and p < 0.001 for the positivity of anti-β2 GP1 antibody, anti-Sm antibody, and lupus anticoagulant). The most common hematologic abnormality was anemia (n = 88, 74.5%), with autoimmune hemolytic anemia constituting the majority (n = 40). Corticosteroids followed by IVIG were the mainstay of treatment. In patients resistant to corticosteroid and IVIG treatments, the most preferred drug was rituximab. Low levels of C3, high SLEDAI score, high incidence of renal involvement, and positive antiphospholipid antibodies were associated with hematological involvement in the univariate analysis. The presence of antiphospholipid antibodies and high SLEDAI score were independently associated with hematological involvement in multivariate analysis (OR: 4.021; 95% CI: 2.041-7.921; p < 0.001 and OR: 1.136; 95% CI: 1.065-1.212; p < 0.001). Conclusion: Hematological abnormalities are frequently encountered in pediatric SLE. Positive antiphospholipid antibodies and high SLEDAI scores were associated with hematological involvement.

The prognostic effect of hemoglobin on patients with cancer cachexia: a multicenter retrospective cohort study

OBJECTIVES

To clarify the influence of hemoglobin on cancer cachexia and to determine whether hemoglobin affects the prognosis or quality of life of patients with cancer cachexia and whether these effects are caused by an interaction between hemoglobin and other factors.

MATERIAL AND METHODS

This study was a multicenter cohort of 2715 patients with cancer cachexia diagnosed from June 2012 to December 2019. The primary outcomes and measures were overall survival (OS) time and all-cause mortality. The association between hemoglobin and all-cause mortality was evaluated using hazard ratios (HRs) and the restricted cubic spline model with a two-sided p-value. Optimal stratification was used to determine the threshold value. We also evaluated the cross-classification of hemoglobin and each variable with survival.

RESULTS

Among the 2715 participants diagnosed with cancer cachexia, 1592 (58.6%) were male, and the mean (SD) age was 58.8 (11.7) years. The optimal cutoff point for hemoglobin as a predictor of cancer cachexia mortality was 140 g/L for males and 101 g/L for females in our research. The decrease in hemoglobin was positively correlated with all-cause mortality. These associations were consistent across cancer subtypes. In the multivariable analysis, after adjusting for sex, age, TNM stage, tumor type, radiotherapy, chemotherapy, Karnofsky performance status score, and other factors, patients diagnosed with cancer cachexia who had low hemoglobin levels were more likely to have a worse prognosis (HR 2.40; 95% CI, 1.12-1.51).

CONCLUSION

Our results suggested that the proposed hemoglobin cutoff point would be valuable for prognostic prediction in patients with cancer cachexia, especially for long-term prognosis.

Safety and efficacy of a single total dose infusion (1020 mg) of ferumoxytol

Purpose:

Iron deficiency anemia (IDA) is the most common type of anemia. A single dose infusion of intravenous (IV) iron is a convenient treatment option. Ferumoxytol is an IV formulation of iron that is typically given in two doses of 510 mg each. Utilizing a single dose of 1020 mg over 15 min has previously been described as safe and effective. In July 2018, we began to administer a single 1020 mg dose of ferumoxytol to patients needing IV iron replacement at the North Florida/South Georgia Veterans Health System. To evaluate the impact of this change, a utilization review was conducted.

Methods:

Outcomes of all patients who received ferumoxytol injections in the 6 months prior to and after the dosing strategy change were analyzed. A total of 140 patients, who received 270 separate IV ferumoxytol infusions, were included in the analysis.

Results:

No significant difference in safety was observed, with one infusion reaction occurring in each group (p = 1.00). Efficacy also appeared equivalent with no significant difference between the change in hemoglobin for those who received a single 1020 mg dose versus those who received two 510 mg doses (p = 0.764). As expected, those who received a single total dose infusion of 1020 mg had less clinic utilization (p < 0.0001).

Conclusion:

In summary, ferumoxytol administered as a 1020 mg single dose infusion was more convenient and should be considered a safe and effective treatment option for IDA.

Multiple myeloma hinders erythropoiesis and causes anaemia owing to high levels of CCL3 in the bone marrow microenvironment

Anaemia is the most common complication of myeloma and is associated with worse clinical outcomes. Although marrow replacement with myeloma cells is widely considered a mechanistic rationale for anaemia, the exact process has not been fully understood. Our large cohort of 1363 myeloma patients had more than 50% of patients with moderate or severe anaemia at the time of diagnosis. Anaemia positively correlated with myeloma cell infiltration in the bone marrow (BM) and worse patient outcomes. The quantity and erythroid differentiation of HSPCs were affected by myeloma cell infiltration in the BM. The master regulators of erythropoiesis, GATA1 and KLF1, were obviously downregulated in myeloma HSPCs. However, the gene encoding the chemokine CCL3 showed significantly upregulated expression. Elevated CCL3 in the BM plasma of myeloma further inhibited the erythropoiesis of HSPCs via activation of CCL3/CCR1/p38 signalling and suppressed GATA1 expression. Treatment with a CCR1 antagonist effectively recovered GATA1 expression and rescued erythropoiesis in HSPCs. Myeloma cell infiltration causes elevated expression of CCL3 in BM, which suppresses the erythropoiesis of HSPCs and results in anaemia by downregulating the level of GATA1 in HSPCs. Thus, our study indicates that targeting CCL3 would be a potential strategy against anaemia and improve the survival of myeloma patients.

Recent update in the pathogenesis and treatment of chemotherapy and cancer induced anemia

Cancer and chemotherapy-induced anemia (CIA) is commonly encountered among patients undergoing active chemotherapy with or without radiation therapy. Its pathogenesis is complex and is often difficult to identify. Symptoms related to CIA may have a negative impact on quality of life and may influence treatment efficacy, disease progression and even survival. The recent major setback of erythropoietin-stimulating agents (ESAs) and the reluctance to transfuse cancer patients with mild and even moderate anemia, had resulted in significant under-treatment of CIA. The discovery of hepcidin and its role in iron homeostasis has revolutionized our understanding of the pathogenesis of iron deficiency and iron overload states. In the present review we examine the multifactorial pathogenesis of CIA, addressing the main mechanisms by which the tumor and immune system affect anemia. Additionally, we discuss the treatment options with more focus on the utilization of the new intravenous iron formulations for this indication.

Anemia in Pediatric Inflammatory Bowel Disease

OBJECTIVES

Anemia is the most frequent extra-intestinal finding in inflammatory bowel disease (IBD). The aim of this study is to determine the prevalence and types of anemia in pediatric patients with IBD at diagnosis and at approximately 1 year follow-up.

METHODS

This is a retrospective chart review of patients diagnosed with IBD from 2005 to 2012, ages 1 to 18 years. Patients who had hemoglobin, hematocrit, mean corpuscular volume, and iron indices obtained at the time of diagnosis and at approximately 1 year follow-up were included in the study. The prevalence of anemia at the beginning and the end of the study was recorded. Using the soluble transferrin receptor index the type of anemia was determined.

RESULTS

At diagnosis, 67.31% of patients were anemic. Overall, 28.85% of patients had either iron deficiency anemia (IDA) or a combination of IDA and anemia of chronic disease (ACD), whereas 38.46% had ACD alone. At follow-up, 20.51% were anemic. 15.38% had either IDA or a combination of IDA and ACD; 5.13% had ACD alone. The pattern of anemia and response to therapy differed among the IBD phenotypes CONCLUSIONS:: Anemia is frequent in inflammatory bowel disease. The prevalence was higher in Crohn disease (CD). At 1 year, the prevalence of anemia decreased significantly, but persisted. Anemia of chronic disease predominated in CD. Iron deficiency anemia continued to be present in CD and ulcerative colitis.

Diagnostics in anaemia of chronic disease in general practice: a real-world retrospective cohort study

Background

Limited research has been performed that focused on the diagnosis of the underlying cause of anaemia of chronic disease (ACD) in general practice or on prevalence data of the underlying causes of ACD in general practice, although this is one of the most common types of anaemia.

Aim

To clarify the diagnostic strategies of GPs in patients newly diagnosed with ACD and to determine the most common underlying causes.

Design & setting

Retrospective cohort study.

Method

Patients newly diagnosed with ACD were selected based on laboratory criteria. ACD was defined as confirmed anaemia and ferritin levels above 100 μg/l combined with decreased iron and/or reduced transferrin. Additional medical information on patients was obtained from the electronic medical files of the GP and/or the referral hospital.

Results

Of the 267 analysed patients with ACD, additional investigations were performed in 205 patients (77%); in 31 patients (12%) the cause was apparent at the time of diagnosis, and for 31 patients (12%) no additional investigations were requested. In 210 (79%) of the 267 patients, an underlying cause was established, with infection (n = 68, 32%), autoimmune disease (n = 51, 24%) and malignancy (n = 48, 23%) as the most frequently observed etiologies. In 35 (13%) of the ACD patients, oral iron supplementation was prescribed by the GP. This was mainly done in patients with severe anaemia or less enhanced ferritin levels.

Conclusion

For most patients with newly diagnosed ACD, the GP undertakes additional investigations to establish underlying causes. However, the cause of ACD remains unknown in a small proportion of patients. The use of oral iron supplementation in these patients requires caution.

The Construction and Characterization of Mitochondrial Ferritin Overexpressing Mice

Mitochondrial ferritin (FtMt) is a H-ferritin-like protein which localizes to mitochondria. Previous studies have shown that this protein can protect mitochondria from iron-induced oxidative damage, while FtMt overexpression in cultured cells decreases cytosolic iron availability and protects against oxidative damage. To investigate the in vivo role of FtMt, we established FtMt overexpressing mice by pro-nucleus microinjection and examined the characteristics of the animals. We first confirmed that the protein levels of FtMt in the transgenic mice were increased compared to wild-type mice. Interestingly, we found no significant differences in the body weights or organ to body weight ratios between wild type and transgenic mice. To determine the effects of FtMt overexpression on baseline murine iron metabolism and hematological indices, we measured serum, heart, liver, spleen, kidney, testis, and brain iron concentrations, liver hepcidin expression and red blood cell parameters. There were no significant differences between wild type and transgenic mice. In conclusion, our results suggest that FtMt overexpressing mice have no significant defects and the overexpression of FtMt does not affect the regulation of iron metabolism significantly in transgenic mice.

A review of anaemia of inflammatory disease in dogs and cats

Anaemia of inflammatory disease is a common cause of anaemia in routine veterinary practice. It is most often mild to moderate, normocytic, normochromic and non-regenerative. Shortened red cell life span, inhibition of iron metabolism and impaired bone marrow response to erythropoietin all contribute to its development. Although anaemia of inflammatory disease is a well-known cause of anaemia in dogs and cats, there is a lack of epidemiological information because specific diagnostic criteria have not been established in veterinary species. Anaemia of inflammatory disease is associated with a poor outcome in various disease states in human medicine; however, its clinical significance and treatment in veterinary medicine are not well understood. This review article describes anaemia of inflammatory disease in dogs and cats and considers its potential significance.

Hepcidin-25 in diabetic chronic kidney disease is predictive for mortality and progression to end stage renal disease

Background

Anemia is common and is associated with impaired clinical outcomes in diabetic chronic kidney disease (CKD). It may be explained by reduced erythropoietin (EPO) synthesis, but recent data suggest that EPO-resistance and diminished iron availability due to inflammation contribute significantly. In this cohort study, we evaluated the impact of hepcidin-25—the key hormone of iron-metabolism—on clinical outcomes in diabetic patients with CKD along with endogenous EPO levels.

Methods

249 diabetic patients with CKD of any stage, excluding end-stage renal disease (ESRD), were enrolled (2003–2005), if they were not on EPO-stimulating agent and iron therapy. Hepcidin-25 levels were measured by radioimmunoassay. The association of hepcidin-25 at baseline with clinical variables was investigated using linear regression models. All-cause mortality and a composite endpoint of CKD progression (ESRD or doubling of serum creatinine) were analyzed by Cox proportional hazards models.

Results

Patients (age 67 yrs, 53% male, GFR 51 ml/min, hemoglobin 131 g/L, EPO 13.5 U/L, hepcidin-25 62.0 ng/ml) were followed for a median time of 4.2 yrs. Forty-nine patients died (19.7%) and forty (16.1%) patients reached the composite endpoint. Elevated hepcidin levels were independently associated with higher ferritin-levels, lower EPO-levels and impaired kidney function (all p<0.05). Hepcidin was related to mortality, along with its interaction with EPO, older age, greater proteinuria and elevated CRP (all p<0.05). Hepcidin was also predictive for progression of CKD, aside from baseline GFR, proteinuria, low albumin- and hemoglobin-levels and a history of CVD (all p<0.05).

Conclusions

We found hepcidin-25 to be associated with EPO and impaired kidney function in diabetic CKD. Elevated hepcidin-25 and EPO-levels were independent predictors of mortality, while hepcidin-25 was also predictive for progression of CKD. Both hepcidin-25 and EPO may represent important prognostic factors of clinical outcome and have the potential to further define “high risk” populations in CKD.

Estrogen contributes to regulating iron metabolism through governing ferroportin signaling via an estrogen response element

Ferroportin (FPN) is the only known iron exporter in mammalian cells, and is universally expressed in most types of cells. FPN signaling plays a crucial role in maintaining iron homeostasis through governing the level of intracellular iron. Serum iron storage is conversely related with the estrogen level in the female bodies, and women in post-menopause are possibly subjected to iron retention. However, the potential effects of estrogen on iron metabolism are not clearly understood. Here, FPN mRNA transcription in all selected estrogen receptor positive (ER+) cells was significantly reduced upon 17β-estradiol (E2) treatment; and this inhibitory effect could be attenuated by ER antagonist tamoxifen. Likewise, in murine bone marrow-derived macrophages (BMDMs), FPN reduction with elevated intracellular iron (reflected by increased ferritin) was observed in response to E2; however, ferritin level barely responded to E2 in FPN-null BMDMs. The observation of inhibition of FPN mRNA expression was not replicated in ER(-) cells upon E2. A functional estrogen response element (ERE) was identified within the promoter of FPN, and this ERE was responsible for the suppressive effect of E2 on FPN expression. Moreover, ovariectomized (OVX) and sham-operated (SHAM) mice were used to further confirm the in vitro finding. The expression of hepatic FPN was induced in OVX mice, compared to that in the SHAM mice. Taken together, our results demonstrated that estrogen is involved in regulating FPN expression through a functional ERE on its promoter, providing additional insights into a vital role of estrogen in iron metabolism.

Disordered hepcidin-ferroportin signaling promotes breast cancer growth

Iron homeostasis is strictly governed in mammals; however, disordered iron metabolism (such as excess iron burden) is recognized as a risk factor for various types of diseases including cancers. Burgeoning evidence indicates that the central signaling of iron homeostasis, the hepcidin-ferroportin axis, is misregulated in cancers. Nonetheless, the mechanisms of misregulated expression of iron-related genes along this signaling in cancers remain largely unknown. In the current study, we found increased levels of serum hepcidin in breast cancer patients. Reduction of hepatic hepcidin through administration of heparin restrained tumorigenic properties of breast tumor cells. Mechanistic investigation revealed that increased iron, bone morphogenetic protein-6 (BMP6) and interleukin-6 (IL-6) jointly promoted the synthesis of hepatic hepcidin. Tumor hepcidin expression was marginally increased in breast tumors relative to adjacent tissues. In contrast, tumor ferroportin concentration was greatly reduced in breast tumors, especially in malignant tumors, compared to adjacent tissues. Elevation of ferroportin concentration inhibited cell proliferation in vitro and in vivo by knocking down tumor hepcidin expression. Additionally, increased IL-6 was demonstrated to jointly enhance the tumorigenic effects of iron through enforcing cell growth. Our combined data overall deciphered the machinery that altered the hepcidin-ferroportin signaling in breast cancers. Thus, targeting the hepcidin-ferroportin signaling would represent a promising therapeutics to restrain breast cancer growth.

The science and practice of micronutrient supplementations in nutritional anemia: an evidence-based review

Nutritional anemia is the most common type of anemia, affecting millions of people in all age groups worldwide. While inadequate access to food and nutrients can lead to anemia, patients with certain health status or medical conditions are also at increased risk of developing nutritional anemia. Iron, cobalamin, and folate are the most recognized micronutrients that are vital for the generation of erythrocytes. Iron deficiency is associated with insufficient production of hemoglobin. Deficiency of cobalamin or folate leads to impaired synthesis of deoxyribonucleic acid, proteins, and cell division. Recent research has demonstrated that the status of copper and zinc in the body can significantly affect iron absorption and utilization. With an increasing number of patients undergoing bariatric surgical procedures, more cases of anemia associated with copper and zinc deficiencies have also emerged. The intestinal absorption of these 5 critical micronutrients are highly regulated and mediated by specific apical transport mechanisms in the enterocytes. Health conditions that persistently alter the histology of the upper intestinal architecture, expression, or function of these substrate-specific transporters, or the normal digestion and flow of these key micronutrients, can lead to nutritional anemia. The focus of this article is to review the science of intestinal micronutrient absorption, discuss the clinical assessment of micronutrient deficiencies in relation to anemia, and suggest an effective treatment plan and monitoring strategies using an evidence-based approach.

Anemia in malignancies: pathogenetic and diagnostic considerations

OBJECTIVES

The aim of this paper is to review the pathogenesis and diagnostic approaches to anemia in cancer patients.

METHODS

PubMed was queried for various combinations of anemia and cancer-related terms using appropriate filters for articles and practice guidelines published in the last 5 years. Specific searches were conducted for individual pathogenetic mechanisms and malignancies of specific anatomic sites.

RESULTS

Anemia is the commonest hematological manifestation of cancer, afflicting 40-64% of patients treated for malignancies. Pathophysiologically, cancer-related anemia can be classified into four broad but overlapping categories: hypoproliferative anemia including the common anemia of inflammation/chronic disease, hemolytic anemia, miscellaneous etiologies, and uncertain etiologies. Anemia incidence increases with the administration of chemotherapy/radiotherapy. It reduces the quality of life and shortens survival in cancer patients. A positive correlation is observed between anemia and tumor hypoxia. Experimentally, hypoxemia enhances tumor growth and resistance to therapy by stimulating angiogenesis, acquisition of genomic mutations, and increasing resistance to apoptosis as well as to the killing effects of chemo/radiotherapy-generated free radicals.

DISCUSSION

Diagnostic approaches to the anemic cancer patient begin with a detailed clinical history and physical examination. Peripheral blood morphology and reticulocyte count are also helpful. Patients with unexplained anemia are evaluated by standard approaches also used in patients of similar age without malignancy. Serum iron profile and bone marrow examination are often required in difficult cases. This review focuses on major aspects of the pathogenesis of the individual entities. Diagnostic approaches and uncommon causes including hemophagocytic lymphohistiocytosis, acquired hemoglobinopathies, and myelodysplasia are also discussed.