Inhibition of human erythroid colony-forming units by interleukin-1 is mediated by gamma interferon

Burden of Child Anemia Attributable to Fine Particulate Matters Brought by Sand Dusts in Low- and Middle-Income Countries

Addressing environmental factors has recently been recommended to curb the growing trend of anemia in low- and middle-income countries (LMICs). Fine particulate matter (PM2.5) generated by dust storms were concentrated in place with a high prevalence of anemia. In a multicounty, multicenter study, we analyzed the association between anemia and life-course averaged exposure to dust PM2.5 among children aged <5 years based on 0.65 million records from 47 LMICs. In the fully adjusted mixed effects model, each 10 μg/m3 increase in life-course averaged exposure to dust PM2.5 was associated with a 9.3% increase in the odds of anemia. The estimated exposure-response association was nonlinear, with a greater effect of dust PM2.5 exposure seen at low concentrations. Applying this association, we found that, in 2017, among all children aged <5 years in the 125 LMICs, dust PM2.5 contributed to 37.98 million cases of anemia. Results indicated that dust PM2.5 contributed a heavier burden than all of the well-identified risk factors did, except for iron deficiency. Our study revealed that long-term exposure to dust PM2.5 can be a novel risk factor, pronouncedly contributed to the burden of child anemia in LMICs, affected by land degradations or arid climate.

Anemia and Its Connections to Inflammation in Older Adults: A Review

Anemia is a common hematological disorder that affects 12% of the community-dwelling population, 40% of hospitalized patients, and 47% of nursing home residents. Our understanding of the impact of inflammation on iron metabolism and erythropoiesis is still lacking. In older adults, anemia can be divided into nutritional deficiency anemia, bleeding anemia, and unexplained anemia. The last type of anemia might be caused by reduced erythropoietin (EPO) activity, progressive EPO resistance of bone marrow erythroid progenitors, and the chronic subclinical pro-inflammatory state. Overall, one-third of older patients with anemia demonstrate a nutritional deficiency, one-third have a chronic subclinical pro-inflammatory state and chronic kidney disease, and one-third suffer from anemia of unknown etiology. Understanding anemia's pathophysiology in people aged 65 and over is crucial because it contributes to frailty, falls, cognitive decline, decreased functional ability, and higher mortality risk. Inflammation produces adverse effects on the cells of the hematological system. These effects include iron deficiency (hypoferremia), reduced EPO production, and the elevated phagocytosis of erythrocytes by hepatic and splenic macrophages. Additionally, inflammation causes enhanced eryptosis due to oxidative stress in the circulation. Identifying mechanisms behind age-related inflammation is essential for a better understanding and preventing anemia in older adults.

Iron metabolism abnormalities in autoimmune hemolytic anemia and Jianpishengxue keli can ameliorate hemolysis and improve iron metabolism in AIHA mouse models

OBJECTIVE

Autoimmune hemolytic anemia (AIHA) is rare heterogeneous disorder characterized by red blood cell (RBC) destruction via auto-antibodies, and after RBC is destroyed, proinflammatory danger-associated molecular patterns including extracellular hemoglobin, heme, and iron which causing cell injury. And oxidative stress represents one of the most significant effects of chronic hemolysis. Jianpishengxue keli can improve the symptoms of anemia patients with kidney disease and tumors and are beneficial in promoting recovery from chronic inflammation. Therefore, it is presumed that Jianpishengxue keli can improve the symptoms of AIHA. We aimed to investigate iron metabolism in AIHA and effects of Jianpishengxue keli on AIHA murine model.

METHODS

Nineteen hemolytic episode AIHA patients, 10 remission patients and 10 healthy controls (HCs) were enrolled in this study. Serum hepcidin, ferritin and other related indicators of iron metabolism were measured. Mouse models of AIHA were established and received high, medium, or low doses of Jianpishengxue keli by gavage daily for 14 and 28 days respectively. The level of RBCs, Hb, bilirubin, LDH, hepcidin, and the expression level of hepcidin mRNA, and hepatic ferroportin 1(FPN1) protein were evaluated.

RESULTS

Serum hepcidin in hemolytic episode AIHA patients and remission patients were significantly higher than that in HCs (p = 0.0083 and p = 0.0473, respectively). Serum ferritin in hemolytic AIHA patients was significantly higher than that in HCs (p = 0.008). Serum transferrin saturation levels are increased in patients with AIHA[ (57.21 ± 8.96) %]. EPO in hemolytic group was higher than that in healthy control (p＜0.05). In AIHA mouse models, IBIL decreased after 14 days of high dose drug intervention. After 28 days, TBIL and IBIL both significantly decreased in all dose groups and LDH significantly decreased in the medium-and high-dose groups. Body weight improved, and the level of RBCs, Hb and hepcidin in the high-dose group returned to normal. After 14 and 28 days of intervention, hepatic hepcidin mRNA in all dose group significantly decreased. Hepatic FPN1 protein which were significantly lower in the AIHA mouse models, increased in all dose groups after drug intervention for 28 days.

CONCLUSION

Iron metabolism abnormalities exists in AIHA patients and Jianpishengxue keli can ameliorate hemolysis and improve iron metabolism in AIHA mouse models.KEY MESSAGESIron metabolism abnormalities exists in hemolytic episode AIHA patients. Hepcidin and ferritin levels significantly elevated and also correlated with the severity of AIHA patients. Jianpishengxue keli can ameliorate hemolysis and prompt the recovery of AIHA.

Hepcidin and its multiple partners: Complex regulation of iron metabolism in health and disease

The peptide hormone hepcidin is central to the regulation of iron metabolism, influencing the movement of iron into the circulation and determining total body iron stores. Its effect on a cellular level involves binding ferroportin, the main iron export protein, preventing iron egress and leading to iron sequestration within ferroportin-expressing cells. Hepcidin expression is enhanced by iron loading and inflammation and suppressed by erythropoietic stimulation. Aberrantly increased hepcidin leads to systemic iron deficiency and/or iron restricted erythropoiesis as occurs in anemia of chronic inflammation. Furthermore, insufficiently elevated hepcidin occurs in multiple diseases associated with iron overload such as hereditary hemochromatosis and iron loading anemias. Abnormal iron metabolism as a consequence of hepcidin dysregulation is an underlying factor resulting in pathophysiology of multiple diseases and several agents aimed at manipulating this pathway have been designed, with some already in clinical trials. In this chapter, we assess the complex regulation of hepcidin, delineate the many binding partners involved in its regulation, and present an update on the development of hepcidin agonists and antagonists in various clinical scenarios.

Inhibition of interleukin-1β reduces myelofibrosis and osteosclerosis in mice with JAK2-V617F driven myeloproliferative neoplasm

Interleukin-1β (IL-1β) is a master regulator of inflammation. Increased activity of IL-1β has been implicated in various pathological conditions including myeloproliferative neoplasms (MPNs). Here we show that IL-1β serum levels and expression of IL-1 receptors on hematopoietic progenitors and stem cells correlate with JAK2-V617F mutant allele fraction in peripheral blood of patients with MPN. We show that the source of IL-1β overproduction in a mouse model of MPN are JAK2-V617F expressing hematopoietic cells. Knockout of IL-1β in hematopoietic cells of JAK2-V617F mice reduces inflammatory cytokines, prevents damage to nestin-positive niche cells and reduces megakaryopoiesis, resulting in decrease of myelofibrosis and osteosclerosis. Inhibition of IL-1β in JAK2-V617F mutant mice by anti-IL-1β antibody also reduces myelofibrosis and osteosclerosis and shows additive effects with ruxolitinib. These results suggest that inhibition of IL-1β with anti-IL-1β antibody alone or in combination with ruxolitinib could have beneficial effects on the clinical course in patients with myelofibrosis.

Challenges in forming inferences from limited data: a case study of malaria parasite maturation

Inferring biological processes from population dynamics is a common challenge in ecology, particularly when faced with incomplete data. This challenge extends to inferring parasite traits from within-host infection dynamics. We focus on rodent malaria infections (Plasmodium berghei), a system for which previous work inferred an immune-mediated extension in the length of the parasite development cycle within red blood cells. By developing a system of delay-differential equations to describe within-host infection dynamics and simulating data, we demonstrate the potential to obtain biased estimates of parasite (and host) traits when key biological processes are not considered. Despite generating infection dynamics using a fixed parasite developmental cycle length, we find that known sources of measurement bias in parasite stage and abundance data can affect estimates of parasite developmental duration, with stage misclassification driving inferences about extended cycle length. We discuss alternative protocols and statistical methods that can mitigate such misestimation.

Anemia May Increase the Overall Risk of Cancer: Findings from a Cohort Study with a 12-Year Follow-up Period in South Korea

BACKGROUND

No previous study has assessed cancer risk in individuals with anemia diagnosed based on hemoglobin levels. Thus, we aimed to investigate whether anemia increases the risk of cancer.

METHODS

Adult individuals who underwent a standardized medical examination during 2002 and 2003 in South Korea were included, and their cancer status was evaluated between January 2004 and December 2015 (12 years) as a primary endpoint. Anemia was defined as serum hemoglobin levels of <12 and <13 g/dL for women and men, respectively.

RESULTS

A total of 454,304 adults were included in the final analysis. Among them, 41,947 (9.2%) and 412,357 (90.8%) individuals constituted the anemia and control groups, respectively. After propensity score matching, a total of 83,886 individuals (41,943 per group) were included in the analysis. Cox regression revealed that the risk of cancer in the anemia group was 3% higher than that in the control group (HR, 1.03; 95% confidence interval, 1.01-1.05; P = 0.023). Specifically, relative to the control group, the anemia group was at an increased risk of gastric (HR, 1.29), esophageal (HR, 1.37), lung (HR, 1.14), and thyroid cancers (HR, 1.14), neoplasms of breast and genital organs (HR, 1.12), and lymphoma or leukemia (HR, 1.63).

CONCLUSIONS

Anemia was independently associated with an increased overall risk of cancer. Further research is required to clarify the associated mechanism.

IMPACT

Anemia was independently associated with an increased overall risk of cancer in the South Korean population.

Experimental modulation of Interleukin 1 shows its key role in chronic kidney disease progression and anemia

Inflammation in chronic kidney disease (CKD) is mostly due to activation of the innate immune system, in which Interleukin-1 (IL-1) is a key player. Anemia of CKD may also be due to erythropoietin (EPO) resistance, clinically associated with inflammation. IL-1 receptor antagonist knockout (RaKO) mice show arthritis and excessive inflammation. Inhibition of IL-1 was shown to be beneficial in many inflammatory conditions, but its role in CKD and anemia is unknown. Here, we report that enhanced inflammation in RaKO mice with CKD provoked both higher degrees of renal insufficiency and anemia in comparison to wild-type CKD, in association with a downregulation of renal hypoxia inducible factor-2 (HIF2) as well as decreased bone marrow EPO-receptor (EPOR) and transferrin receptor (TFR). In contrast, administration of P2D7KK, an anti-IL1b monoclonal antibody, to CKD mice results in a lower grade of systemic inflammation, better renal function and blunted anemia. The latter was associated with upregulation of renal HIF-2α, bone marrow EPO-R and TFR. Altogether, this supports the key role of inflammation, and IL-1 particularly, in CKD progression and anemia. Novel treatments to reduce inflammation through this and other pathways, may improve renal function, attenuate the anemic state or increase the response to exogenous EPO.

Anemia in patients with Covid-19: pathogenesis and clinical significance

COVID-19 patients typically present with lower airway disease, although involvement of other organ systems is usually the rule. Hematological manifestations such as thrombocytopenia and reduced lymphocyte and eosinophil numbers are highly prevalent in COVID-19 and have prognostic significance. Few data, however, are available about the prevalence and significance of anemia in COVID-19. In an observational study, we investigated the prevalence, pathogenesis and clinical significance of anemia among 206 patients with COVID-19 at the time of their hospitalization in an Internal Medicine unit. The prevalence of anemia was 61% in COVID-19, compared with 45% in a control group of 71 patients with clinical and laboratory findings suggestive of COVID-19, but nasopharyngeal swab tests negative for SARS-CoV-2 RNA (p = 0.022). Mortality was higher in SARS-CoV-2 positive patients. In COVID-19, females had lower hemoglobin concentration than males and a higher prevalence of moderate/severe anemia (25% versus 13%, p = 0.032). In most cases, anemia was mild and due to inflammation, sometimes associated with iron and/or vitamin deficiencies. Determinants of hemoglobin concentration included: erythrocyte sedimentation rate, serum cholinesterase, ferritin and protein concentrations and number of chronic diseases affecting each patient. Hemoglobin concentration was not related to overall survival that was, on the contrary, influenced by red blood cell distribution width, age, lactate dehydrogenase and the ratio of arterial partial oxygen pressure to inspired oxygen fraction. In conclusion, our results highlight anemia as a common manifestation in COVID-19. Although anemia does not directly influence mortality, it usually affects elderly, frail patients and can negatively influence their quality of life.

Oxidative DNA Damage, Inflammatory Signature, and Altered Erythrocytes Properties in Diamond-Blackfan Anemia

Molecular pathophysiology of Diamond-Blackfan anemia (DBA) involves disrupted erythroid-lineage proliferation, differentiation and apoptosis; with the activation of p53 considered as a key component. Recently, oxidative stress was proposed to play an important role in DBA pathophysiology as well. CRISPR/Cas9-created Rpl5- and Rps19-deficient murine erythroleukemia (MEL) cells and DBA patients' samples were used to evaluate proinflammatory cytokines, oxidative stress, DNA damage and DNA damage response. We demonstrated that the antioxidant defense capacity of Rp-mutant cells is insufficient to meet the greater reactive oxygen species (ROS) production which leads to oxidative DNA damage, cellular senescence and activation of DNA damage response signaling in the developing erythroblasts and altered characteristics of mature erythrocytes. We also showed that the disturbed balance between ROS formation and antioxidant defense is accompanied by the upregulation of proinflammatory cytokines. Finally, the alterations detected in the membrane of DBA erythrocytes may cause their enhanced recognition and destruction by reticuloendothelial macrophages, especially during infections. We propose that the extent of oxidative stress and the ability to activate antioxidant defense systems may contribute to high heterogeneity of clinical symptoms and response to therapy observed in DBA patients.

Bacterial Lipopolysaccharides Suppress Erythroblastic Islands and Erythropoiesis in the Bone Marrow in an Extrinsic and G- CSF-, IL-1-, and TNF-Independent Manner

Anemia of inflammation (AI) is the second most prevalent anemia after iron deficiency anemia and results in persistent low blood erythrocytes and hemoglobin, fatigue, weakness, and early death. Anemia of inflammation is common in people with chronic inflammation, chronic infections, or sepsis. Although several studies have reported the effect of inflammation on stress erythropoiesis and iron homeostasis, the mechanisms by which inflammation suppresses erythropoiesis in the bone marrow (BM), where differentiation and maturation of erythroid cells from hematopoietic stem cells (HSCs) occurs, have not been extensively studied. Here we show that in a mouse model of acute sepsis, bacterial lipopolysaccharides (LPS) suppress medullary erythroblastic islands (EBIs) and erythropoiesis in a TLR-4- and MyD88-dependent manner with concomitant mobilization of HSCs. LPS suppressive effect on erythropoiesis is indirect as erythroid progenitors and erythroblasts do not express TLR-4 whereas EBI macrophages do. Using cytokine receptor gene knock-out mice LPS-induced mobilization of HSCs is G-CSF-dependent whereas LPS-induced suppression of medullary erythropoiesis does not require G- CSF-, IL- 1-, or TNF-mediated signaling. Therefore suppression of medullary erythropoiesis and mobilization of HSCs in response to LPS are mechanistically distinct. Our findings also suggest that EBI macrophages in the BM may sense innate immune stimuli in response to acute inflammation or infections to rapidly convert to a pro-inflammatory function at the expense of their erythropoietic function.

Reduction in total leukocytes in malaria patients compared to febrile controls: A systematic review and meta-analysis

BACKGROUND

Leukocyte alterations are a common hematological alteration among malaria patients.

OBJECTIVES

This systematic review and meta-analysis aimed to provide data and evidence comparing alterations in total leukocyte counts in malaria patients compared to febrile/healthy subjects at baseline before treatment. A systematic review was conducted by following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement for reporting systematic reviews and meta-analyses.

DATA SOURCES

Web of Science (ISI), Scopus, and Medline.

STUDY ELIGIBILITY CRITERIA, PARTICIPANTS, AND INTERVENTIONS

All published articles reporting a total leukocyte count of patients infected with malaria, non-malaria (febrile or healthy group) at baseline before treatment before August 27, 2019, were retrieved, and data were extracted by two main reviewers independently.

STUDY APPRAISAL AND SYNTHESIS METHODS

We used a forest plot, heterogeneity test (Cochran's Q), and the degree of heterogeneity (I2) to test whether the included studies were heterogeneous. The quality of the included studies was determined by a quality assessment guide based on the quality assessment tool developed by the Newcastle-Ottawa Scale (NOS). Cochran's Q (Chi-square) and Moran's I2 were used to evaluate heterogeneity. Meta-regression using STATA software was conducted to find the source of heterogeneity. A funnel plot with Egger's test was used to examine the significance of publication bias among the included studies. The mean differences were estimated using a random-effects model.

RESULTS

Out of the 2,261 articles screened, 29 articles were included in this systematic review and meta-analysis. The heterogeneity test indicated that there was heterogeneity among the included studies with no publication bias. The meta-analysis demonstrated that the total leukocyte count was significantly lower in patients with malaria (n = 4,619) than in those without malaria (n = 10,056) (Z = 4.0, P-value < 0.00001, mean difference = -1.38, 95% CI = -2.06-(-0.71)). Leukocyte differential alterations, low lymphocyte counts (P-value <0.0001, mean difference = -1.03, 95% CI = -1.53-(-0.53)) and a high NL ratio were found in the malaria group (n = 1,579) compared to the non-malaria group (n = 4,991) (P-value <0.0001, mean difference = 0.6, 95% CI = 0.32-0.88). The subgroup analysis indicated that there was a significantly lower total leukocyte count in the malaria group (n = 3,545) than in the febrile group (n = 8,947) (Z = 1.33, P-value < 0.0001, mean difference = -1.76, 95% CI = -2.56-(-0.96)), but no significant difference was found between the malaria group (n = 1,232) and the healthy group (n = 1,679) (P-value > 0.05).

LIMITATIONS

As the specific diagnoses in the febrile groups were not reported in the included studies so that the results of the present study need to be carefully interpreted.

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

This systematic review demonstrated that the total leukocyte count was affected by malarial infection at baseline despite the heterogeneity of the included studies. Future work must aim to understand the treatment-related total leukocyte reduction during follow-up or post-treatment outcomes in malaria-endemic settings.

Inflammatory Pathways to Anemia in the Frail Elderly

Anemia is a common, yet often overlooked, geriatric syndrome characterized by reduced hemoglobin levels and associated with adverse health outcomes and early mortality. Evidence suggests that anemia is an independent risk factor for frailty in older adults. In this article, the authors review the evidence for the role of chronic inflammation in the pathogenesis of anemia in the frail elderly. Understanding the relationships between anemia, frailty, and chronic inflammation will pave the way for the development of novel interventional strategies for the treatment and prevention of anemia and, likely, also frailty in older adults.

Hepcidin-ferroportin axis in health and disease

Hepcidin is central to regulation of iron metabolism. Its effect on a cellular level involves binding ferroportin, the main iron export protein, resulting in its internalization and degradation and leading to iron sequestration within ferroportin-expressing cells. Aberrantly increased hepcidin leads to systemic iron deficiency and/or iron restricted erythropoiesis. Furthermore, insufficiently elevated hepcidin occurs in multiple diseases associated with iron overload. Abnormal iron metabolism as a consequence of hepcidin dysregulation is an underlying factor resulting in pathophysiology of multiple diseases and several agents aimed at manipulating this pathway have been designed, with some already in clinical trials. In this chapter, we present an overview of and rationale for exploring the development of hepcidin agonists and antagonists in various clinical scenarios.

Frequency and causes of anemia in Lymphoma patients

Objective:

Purpose of this study was to find out frequency of anemia and its causes in newly diagnosed treatment naive lymphoma patients.

Methods:

We retrospectively studied all lymphoma patients (> 18 years age) diagnosed and treated at Shaukat Khanum Memorial Cancer Hospital and Research Centre, from January 2016 till January 2017. The data was collected from electronic Hospital Information System. Descriptive statistics were done by using summary measures for categorical variables as well as continuous variables.

Results:

Out of a total 408 patients, 272 were males and 136 females. Median age of patients was 33 years (18-76). Hodgkin lymphoma (HL) and diffuse large B cell lymphoma (DLBCL) were the diagnosis in 201 and 134 patients respectively; rest of the patients had low grade lymphomas. Anemia was present in 184 (45%) patients. Anemia of chronic disease was the commonest cause of anemia and was present in 61 (33.1%) patients. Remaining patients had anemia secondary to marrow involvement 50(27.17%); iron deficiency anemia, Vitamin B-12 deficiency anemia and hemolytic anemia were the causes in 7.6, 1.6%, % and 0.54% respectively.

Conclusion:

Anemia is a common feature in newly diagnosed lymphoma patients with anemia of chronic disease as the commonest cause. It is more frequent in patients with higher stages of lymphoma especially when bone marrow is involved by lymphoma. Since anemia is an important adverse prognostic factor for the outcome of lymphoma patients, work up for anemia prior to initiation of chemotherapy should be done in every lymphoma patient in order to help improve the management of these patients.

In a Mouse Model of Sepsis, Hepcidin Ablation Ameliorates Anemia More Effectively than Iron and Erythropoietin Treatment

Intensive care unit (ICU) anemia is an extreme version of anemia of inflammation that occurs commonly in critically ill patients and is associated with increased morbidity and mortality. Currently available therapies for ICU anemia have shown inconsistent efficacies in clinical trials. We conducted a systematic study of the effects of early versus delayed iron (Fe) and/or erythropoietin (EPO) therapy in our previously characterized mouse model of ICU anemia based on an injection of heat-killed Brucella abortus. To study the effects of ongoing inflammation on the response to therapy, inflamed wild-type (WT) and hepcidin knockout (HKO) mice were treated at either early (days 1 and 2) or delayed (days 7 and 8) time points after the inflammatory stimulus. In the early treatment group, Fe and/or EPO therapy did not increase hemoglobin (Hgb) levels or reticulocyte production in either the inflamed WT or HKO groups. In the delayed treatment group, combination Fe + EPO therapy did increase Hgb and reticulocyte production in WT mice (mean ΔHgb in WT saline group -9.2 g/dL vs. Fe/EPO -5.5 g/dL; P < 0.001). The HKO mice in the delayed treatment group did not improve their Hgb, but HKO mice in all treatment groups developed a milder anemia than the WT mice. Our findings indicate that combination Fe + EPO therapy is effective in partially reversing ICU anemia when administered after the phase of acute inflammation. Hepcidin ablation alone was more effective in attenuating ICU anemia than Fe + EPO therapy, which indicates the potential of antihepcidin therapeutics in treating ICU anemia.

Role of hepcidin-ferroportin axis in the pathophysiology, diagnosis, and treatment of anemia of chronic inflammation

Anemia of chronic inflammation (ACI) is a frequently diagnosed anemia and portends an independently increased morbidity and poor outcome associated with multiple underlying diseases. The pathophysiology of ACI is multifactorial, resulting from the effects of inflammatory cytokines which both directly and indirectly suppress erythropoiesis. Recent advances in molecular understanding of iron metabolism provide strong evidence that immune mediators, such as IL-6, lead to hepcidin-induced hypoferremia, iron sequestration, and decreased iron availability for erythropoiesis. The role of hepcidin-ferroportin axis in the pathophysiology of ACI is stimulating the development of new diagnostics and targeted therapies. In this review, we present an overview of and rationale for inflammation-, iron-, and erythropoiesis-related strategies currently in development.

Relation between dynamic change of red cell distribution width and 30-day mortality in patients with acute pulmonary embolism

INTRODUCTION AND OBJECTIVES

Recent studies suggest that an increase in red cell distribution width (RDW) levels have a better prognostic value than a single measurement. In the current study, we investigated the predictive value of increasing RDW levels for mortality in acute pulmonary emboli (APE) patients.

MATERIALS AND METHODS

For the study, 199 APE patients who were hospitalized were enrolled. Patients were divided into three groups according to their admission and 24th hour RDW values. Patients for whom both RDW values normal were put in group 1 (normal); patients with admission RDW > 14.5% and decreased 24th hour RDW values were in group 2 (decreased); patients whose 24th hour RDW levels were >14.5% and increased compared to their baseline RDW measurement were in group 3 (increased). Clinical and laboratory findings and 30-day mortality of these groups were compared.

RESULTS

Mean patient age was 68 ± 16, and 48% of the patients were male. There were 98 patients (49%) in group 1, 59 patients (30%) in group 2, and 42 patients (21%) in group 3. Patients in group 3 were older, had lower eGFR and hemoglobin values, and had higher brain type natriuretic peptide values. Mortality rate was higher in group 3 (0%, 3.4%, 19%, respectively, P < .0001). Increase in RDW was independently related to mortality [HR: 4.9, (95%CI: 1.2-18, P = .02)].

CONCLUSION

APE patients with increasing RDW levels have higher mortality rates. Serial measurements of RDW may help us determine patients with high risk for mortality.

Intratumoural interleukin 12 gene therapy stimulates the immune system and decreases angiogenesis in dogs with spontaneous cancer

Interleukin 12 (IL-12) is a powerful immunostimulatory cytokine with a strong antitumoural activity. In this work, the immunological, anti-angiogenic and clinical effects of three consecutive intratumoural IL-12 electrogene therapy (EGT) treatments were evaluated in nine dogs with spontaneous cancer. In all the dogs, tumour biopsies and blood samples were taken prior, during and after the intratumoural IL-12 EGT (on days 1, 8, 35 and 1, 3, 8, 15, 35, respectively). An initial decrease in immune cells was followed by an increase above baseline 1-3 weeks after treatment initiation. Interestingly, the decrease in peripheral leukocytes 2 days after the first intratumoural IL-12 EGT coincided with erythema and tumour swelling. Transient increases of IL-12 and interferon γ were measured in the serum and the tumour tissue, whereas IL-10 transiently increased only in the serum. The effect of intratumoural IL-12 EGT on the levels of IL-24 and vascular endothelial growth factor in the sera and tumour biopsies differed per dog. Via contrast-enhanced ultrasound (US) (on days 1, 8 and 35), we demonstrated that intratumoural IL-12 EGT resulted in a significant decrease of the relative blood volume and blood flow speed in the tumour compared with baseline. Metastases were present in two dogs. In one of these dogs, IL-12 EGT of the primary tumour caused a transient partial regression of the metastases, but not of the primary tumour. The second dog with metastases did not survive long enough to complete the entire treatment cycle. Despite encouraging immunostimulatory and anti-angiogenic effects after intratumoural IL-12 EGT, no clinically relevant outcomes were observed in this study, as persistent tumour regression could not be obtained. On the other hand, the laboratory and US results hold great promise for combinatorial strategies of intratumoural IL-12 EGT with conventional antitumour (immuno)therapies.

Red cell distribution width and mortality in carotid atherosclerosis

BACKGROUND

Red cell distribution width (RDW) is associated with morbidity and mortality in chronic cardiac disease. The aim of the present study was to investigate the role of RDW as a predictor of adverse outcome in patients with carotid atherosclerosis.

MATERIALS AND METHODS

We prospectively studied 1065 of 1286 consecutive patients with neurological asymptomatic carotid artery stenosis as assessed by duplex Doppler sonography. The study end points were all-cause mortality and cardiovascular mortality respectively.

RESULTS

During a median follow-up time of 6·2 years (interquartile range 5·9-6·6), corresponding to 5551 overall person-years, 275 patients (25·8%) died. Of them, 182 patients (66·2%) died due to cardiovascular causes. RDW was significantly associated with adverse outcome. In a continuous multivariate Cox regression analysis, the adjusted hazard ratio for each per cent increase in RDW was 1·39 (95% CI 1·27-1·53; P < 0·001) for all-cause and 1·43 (95% CI 1·28-1·60; P < 0·001) for cardiovascular mortality respectively. Kaplan-Meier estimates showed a gradual relationship between increasing quartiles of RDW and death (log rank P < 0·001). Adjusted hazard ratios for all-cause death ranged from 0·89 to 1·94 for the highest vs. the lowest quartile (P < 0·001 for trend) and for cardiovascular death from 1·08 to 2·34 for the highest vs. the lowest quartile (P < 0·001 for trend) respectively.

CONCLUSIONS

Red cell distribution width was significantly and independently associated with all-cause and cardiovascular death in patients with asymptomatic carotid atherosclerosis.

The homeobox gene DLX4 regulates erythro-megakaryocytic differentiation by stimulating IL-1β and NF-κB signaling

Megakaryocyte and erythroid development are tightly controlled by a repertoire of cytokines, but it is not clear how cytokine-activated signaling pathways are controlled during development of these two lineages. Here, we identify that expression of DLX4, a transcription factor encoded by a homeobox gene, increases during megakaryopoiesis but decreases during erythropoiesis. Enforced expression of DLX4 in CD34(+) stem and progenitor cells and in bipotent K562 cells induced lineage markers and morphologic features of megakaryocytes and repressed erythroid marker expression and hemoglobin levels. Converse results were obtained when DLX4 was knocked down. Gene Ontology and Gene Set Enrichment Analyses of genome-wide changes in gene expression revealed that DLX4 induces a megakaryocytic transcriptional program and inhibits an erythroid transcriptional program. DLX4 also induced gene signatures that are associated with nuclear factor κB (NF-κB) signaling. The ability of DLX4 to promote megakaryocyte development at the expense of erythroid generation was diminished by blocking NF-κB activity or by repressing IL1B, a transcriptional target of DLX4. Collectively, our findings indicate that DLX4 exerts opposing effects on the megakaryocytic and erythroid lineages in part by inducing IL-1β and NF-κB signaling.

The significance of pretreatment anemia in the era of R-IPI and NCCN-IPI prognostic risk assessment tools: a dual-center study in diffuse large B-cell lymphoma patients

BACKGROUND

Anemia is frequently identified at the time of diagnosis in patients with diffuse large B-cell lymphoma (DLBCL); however, studies addressing the prognostic significance of this important clinical parameter are lacking.

METHODS

In this dual-center study of patients with DLBCL (n = 556) treated with rituximab-containing regimens, we evaluated the prognostic relevance of anemia at diagnosis in a training set (n = 211) and validated our findings in a second independent patient cohort (n = 345). Using Kaplan-Meier curves as well as univariate and multivariate Cox regression models, we analyzed the impact of anemia on 5-year overall survival (OS) and 5-year disease-free survival (DFS) alongside established prognostic indicators including age, tumor stage, the revised International Prognostic Index (R-IPI), and the recently published NCCN-IPI. The influence of anemia on the predictive accuracy of IPI, R-IPI, and NCCN-IPI prognosis scores was subsequently determined using the Harrell's concordance index.

RESULTS

Anemia was an independent predictor of impaired OS and DFS at 5 years in both DLBCL patient cohorts (P < 0.001, log-rank test). In multivariate analysis, hemoglobin level was also a strong and independent prognostic indicator in patients stratified according to R-IPI or NCCN-IPI score. In survival analysis, the estimated concordance index, using IPI, R-IPI, and NCCN-IPI stratification measures (0.69, 0.64, and 0.70, respectively), improved to 0.70, 0.68, and 0.73, respectively, when anemia was also considered.

CONCLUSION

In this study, we have demonstrated that anemia at the time of diagnosis is an independent predictor of impaired clinical outcome in DLBCL. Furthermore, consideration of hemoglobin levels may improve the accuracy of recently established prognostic tools in lymphoma. Our data encourage further evaluation of the prognostic utility of this readily accessible biological parameter in prospective clinical trials.

Anemia of inflammation

Anemia of inflammation (AI, also called anemia of chronic disease) is a common, typically normocytic, normochromic anemia that is caused by an underlying inflammatory disease. It is diagnosed when serum iron concentrations are low despite adequate iron stores, as evidenced by serum ferritin that is not low. In the setting of inflammation, it may be difficult to differentiate AI from iron deficiency anemia, and the 2 conditions may coexist. Treatment should focus on the underlying disease. Recent advances in molecular understanding of AI are stimulating the development of new pathophysiologically targeted experimental therapies.

Interrelationship between chronic periodontitis and anemia: A 6-month follow-up study

Background:

In India, anemia is a common and serious health disorder among both sexes and all age groups, with anemia of chronic disease (ACD) being the second most prevalent anemia. Periodontitis is an inflammatory disease of the supporting tissues of the tooth caused by specific microorganisms. An immune response to bacteria and their products induces a major vascular response, offering explanatory mechanisms for the interactions between periodontal infection and a variety of systemic disorders. Therefore, periodontitis results in low-grade systemic inflammation, which may cause lower number of erythrocytes and, consequently, lower hemoglobin concentration.

Materials and Methods:

A total of 100 systemically healthy male patients visiting the outpatient department participated in the study. Of these, 50 patients had healthy periodontium and 50 patients had chronic periodontitis. Clinical parameters and red blood cell parameters of all the patients were assessed at baseline and 6 months after non-surgical periodontal therapy. Statistical analysis using Student's t-test was performed.

Results:

Data analysis revealed that patients with chronic periodontitis showed an improvement in both clinical and red blood cell parameters from baseline to 6 months after non-surgical periodontal therapy.

Conclusion:

From the present study, it can be concluded that like any other chronic condition, chronic periodontitis can lead to ACD. It also provides evidence that non-surgical periodontal therapy can improve the anemic status of patients with chronic periodontitis.

Distinct roles for hepcidin and interleukin-6 in the recovery from anemia in mice injected with heat-killed Brucella abortus

Anemia of inflammation (AI) is commonly observed in chronic inflammatory states and may hinder patient recovery and survival. Induction of hepcidin, mediated by interleukin 6, leads to iron-restricted erythropoiesis and anemia. Several translational studies have been directed at neutralizing hepcidin overexpression as a therapeutic strategy against AI. However, additional hepcidin-independent mechanisms contribute to AI, which are likely mediated by a direct effect of inflammatory cytokines on erythropoiesis. In this study, we used wild-type, hepcidin knockout (Hamp-KO) and interleukin 6 knockout (IL-6-KO) mice as models of AI. AI was induced with heat-killed Brucella abortus (BA). The distinct roles of iron metabolism and inflammation triggered by interleukin 6 and hepcidin were investigated. BA-treated wild-type mice showed increased expression of hepcidin and inflammatory cytokines, as well as transitory suppression of erythropoiesis and shortened red blood cell lifespan, all of which contributed to the severe anemia of these mice. In contrast, BA-treated Hamp-KO or IL-6-KO mice showed milder anemia and faster recovery compared with normal mice. Moreover, they exhibited different patterns in the development and resolution of anemia, supporting the notion that interleukin 6 and hepcidin play distinct roles in modulating erythropoiesis in AI.

Isocitrate ameliorates anemia by suppressing the erythroid iron restriction response

The unique sensitivity of early red cell progenitors to iron deprivation, known as the erythroid iron restriction response, serves as a basis for human anemias globally. This response impairs erythropoietin-driven erythropoiesis and underlies erythropoietic repression in iron deficiency anemia. Mechanistically, the erythroid iron restriction response results from inactivation of aconitase enzymes and can be suppressed by providing the aconitase product isocitrate. Recent studies have implicated the erythroid iron restriction response in anemia of chronic disease and inflammation (ACDI), offering new therapeutic avenues for a major clinical problem; however, inflammatory signals may also directly repress erythropoiesis in ACDI. Here, we show that suppression of the erythroid iron restriction response by isocitrate administration corrected anemia and erythropoietic defects in rats with ACDI. In vitro studies demonstrated that erythroid repression by inflammatory signaling is potently modulated by the erythroid iron restriction response in a kinase-dependent pathway involving induction of the erythroid-inhibitory transcription factor PU.1. These results reveal the integration of iron and inflammatory inputs in a therapeutically tractable erythropoietic regulatory circuit.

Malaria: a haematological disease

Plasmodium falciparum malaria remains a major cause of mortality throughout the tropical world. Haematological abnormalities are considered a hallmark of malaria, bearing an impact on final outcome and representing indices of prognostic and follow-up value. These include severe anaemia, coagulation disturbances, leukocyte numerical or functional changes and spleen involvement. Anaemia involves red blood cell lysis due to parasite invasion, as well as mechanisms of intravascular haemolysis and decreased erythropoiesis. Exchange or blood transfusion is mainly recommended in the management of these patients. Haemorrhagic complications in severe malaria are relatively rare despite prominent thrombocytopenia and dysfunction in the coagulation pathway. Numerical, as well as functional changes in the white blood cell are less dramatic than other blood cell series, but still, remain a significant index of disease progression and ultimate prognosis. Finally, the role of the spleen in severe malaria is multifactorial. Care and vigilance should be taken against splenic rupture which is fatal and can occur despite appropriate antimalarial prophylaxis and treatment.

Prognostic value of C-reactive protein, lactase dehydrogenase and anemia in recurrent or refractory aggressive lymphoma

OBJECTIVE

Prognostic predictors for newly diagnosed malignant lymphoma are well known. However, they have not been compared for patients with recurrent or refractory malignant lymphoma.

METHODS

We retrospectively analyzed biological prognostic predictors for patients with recurrent or refractory aggressive lymphoma, such as serum levels of C-reactive protein, lactate dehydrogenase, hemoglobin, β2-microglobulin and soluble interleukin-2 receptor before salvage therapy. The primary endpoint was overall survival after salvage treatment. First, univariate and multivariate analyses were performed for each of the parameters, using the log-rank test and Cox regression analysis, respectively. Secondly, we classified the patients into three risk groups on the basis of significant poor predictors.

RESULTS

Sixty-three patients, including 41 patients with diffuse large B-cell lymphoma, were included in this study. Overall survival was significantly worse in patients with elevated C-reactive protein level (hazard ratio 3.757; P = 0.017), elevated lactate dehydrogenase level (hazard ratio 3.948; P = 0.010) and anemia (hazard ratio 3.925; P = 0.016) by multivariate analysis. We classified patients into two groups based on these three biological parameters. The median overall survival of the high- and low-risk patients was 5.8 and 60.1 months, respectively (log-rank test; P < 0.001). The overall response rate was significantly higher among the low-risk patients than among the high-risk patients (71.4 versus 28.6%, P = 0.005). Those results were similar among all aggressive lymphoma and diffuse large B-cell lymphoma.

CONCLUSIONS

Elevated C-reactive protein level, elevated lactate dehydrogenase level and anemia before salvage treatment predicted poorer outcomes among patients with recurrent or refractory aggressive lymphoma.

Anti-erythropoietin receptor antibodies in systemic lupus erythematosus patients with anemia

Anemia is a common hematologic abnormality in systemic lupus erythematosus (SLE). An inadequate erythropoietin (EPO) response in SLE patients with anemia has been described that may be due to the presence of antibodies to EPO in SLE patients. However, whether anemia in patients with SLE is related to antibodies to EPO receptor (EPOR) has not yet been investigated. We enlisted 169 consecutive patients with SLE and 45 normal individuals to investigate the existence and importance of circulating autoantibodies to EPOR in sera from patients with SLE. In all patients with SLE, the disease activity was evaluated by using the SLE disease activity index SLEDAI. Anti-EPOR antibodies were detected by using an enzyme-linked immunosorbent assay (ELISA). A higher frequency of anti-EPOR antibodies was observed in SLE patients than in healthy controls (18.3% vs 2.2%, p = 0.007). Moreover, anti-EPOR antibodies were detected in 22 of 69 (31.9%) SLE patients with anemia and in only nine of 100 (9.0%, p < 0.001) in those without. Furthermore, the patients with anti-EPOR antibodies exhibited more severe anemia and often presented as microcytic anemia (p = 0.001). Finally, anti-EPOR antibodies seemed more likely to occur in patients with rash (p = 0.008), lower levels of C(3) component (p = 0.01), higher titer of anti-dsDNA antibodies (p < 0.001) and higher disease activity scores (p = 0.024). The results of this study suggest that anti-EPOR antibodies might play a vital role in SLE patients developing anemia because of the higher incidence of antibodies to EPOR found in SLE patients with anemia. Thus, there might be clinical value in detecting anti-EPOR antibodies in SLE patients with anemia. Therefore, the pathologic role of the antibodies in inducing anemia needs to be established in future studies.

Shortened red blood cell lifespan is related to the dose of erythropoiesis-stimulating agents requirement in patients on hemodialysis

Renal anemia is an important complication of chronic kidney disease (CKD). One of the most important complications of renal anemia is reduced red blood cell (RBC) lifespan, but there has been little research conducted into the causes of and treatments for this anemia. We measured alveolar carbon monoxide (CO) and then estimated RBC lifespan in patients on hemodialysis (HD). We also examined their requirement for erythropoiesis-stimulating agents (ESA), HD dose, nutrition factors, iron metabolism factor, reticulocyte counts and % reticulocytes. We enrolled 140 patients undergoing intermittent HD; among this group, 31 were not administered ESA and the others were on ESA therapy. Twelve healthy volunteers served as controls. The RBC lifespans in the healthy volunteers and in the HD patients were 128 ± 28 and 89 ± 28 days (mean ± SD), respectively. The RBC lifespan significantly and negatively correlated with ESA requirement (r = -0.489, P < 0.0001) in the HD patients. Other factors suspected to influence the RBC lifespan did not significantly correlate with the RBC lifespan in HD patients, in contrast to the correlation observed for S-Cr, BUN, S-ALB and total cholesterol vs. RBC lifespan. A shortened RBC lifespan seems to rather significantly affect the ESA requirement. Better nutritional status or active HD patients also seem to have longer RBC lifespans and lower ESA requirement.

Relationship between inflammatory mediator patterns and anemia in HIV-1 positive and exposed children with Plasmodium falciparum malaria

Anemia is the primary hematological manifestation of both Plasmodium falciparum malaria and HIV-1 in pediatric populations in sub-Saharan Africa. We have previously shown that HIV-1 positive and exposed children have greater risk of developing severe anemia (hemoglobin, Hb <6.0 g dL⁻¹) during acute malaria. However, enhanced severity of anemia was unrelated to either erythropoietic suppression or parasite-driven red blood cell hemolysis. To further explore mechanisms of anemia, circulating inflammatory mediators (IMs) were determined using a 25-plex bead array in P. falciparum-infected (Pf[+]) children (3-36 month, n = 194) stratified into three groups: HIV-1 negative (HIV-1[-]/Pf[+]); HIV-1 exposed (HIV-1[exp]/Pf[+]); and HIV-1 infected (HIV-1[+]/Pf[+]). IL-12, MIG/CXCL9, eotaxin/CCL11, and GM-CSF differed significantly and progressively increased across the groups (HIV-1[-]→HIV-1[exp]→HIV-1[+]). To further explore the relationship between the inflammatory milieu (i.e., cytokines, chemokines, and growth factors) and HIV-1 status, the large panel of IMs was reduced into discrete groups by principal component factor analysis. Of the six principal components that emerged, three components were significantly higher in the HIV-1 [+]/pf[+] and HIV[exp]/Pf[+] groups, demonstrating that inflammatory profiles differ according to HIV-1 status. Additional analyses exploring the relationship between the components and anemia revealed significant positive correlations between Hb and Component 3 (IL-1Ra, IL-7, IL-17, IFN-α, IFN-γ, MIG/CXCL9) in the HIV-1[-]/Pf[+] group, and Component 4 (IL-4, IL-5, IL-12, Eotaxin/CCL11) in HIV-1[+]/Pf[+] children. Further analyses of the HIV-1[+]/Pf[+] group revealed that IL-12 had the strongest association with anemia. Results presented here demonstrate that there are unique relationships between the inflammatory environment and anemia in HIV-1 positive and exposed children with malaria.

Pro-inflammatory cytokine-mediated anemia: regarding molecular mechanisms of erythropoiesis

Anemia of cancer and chronic inflammatory diseases is a frequent complication affecting quality of life. For cancer patients it represents a particularly bad prognostic. Low level of erythropoietin is considered as one of the causes of anemia in these pathologies. The deficiency in erythropoietin production results from pro-inflammatory cytokines effect. However, few data is available concerning molecular mechanisms involved in cytokine-mediated anemia. Some recent publications have demonstrated the direct effect of pro-inflammatory cytokines on cell differentiation towards erythroid pathway, without erythropoietin defect. This suggested that pro-inflammatory cytokine-mediated signaling pathways affect erythropoietin activity. They could interfere with erythropoietin-mediated signaling pathways, inducing early apoptosis and perturbing the expression and regulation of specific transcription factors involved in the control of erythroid differentiation. In this review we summarize the effect of tumor necrosis factor (TNF)α, TNF-related apoptosis-inducing ligand (TRAIL), and interferon (IFN)-γ on erythropoiesis with a particular interest for molecular feature.

Clinical analysis of primary Sjögren's syndrome complicating anemia

This is a cross-sectional study to assess the prevalence and causes of anemia in the primary Sjögren's syndrome (pSS). One hundred and thirty-two consecutive patients with pSS were enrolled into the study. Standard hematological and immunological tests and examination of bone marrow were performed. Anemia occurred in 45 (34.1%) patients. The causes of anemia included anemia of chronic disease (69%), autoimmune hemolytic anemia (AIHA, 18%), iron deficiency anemia (9%) and other causes (4%), of which AIHA caused the most severe anemia. The prevalence of ANA, anti-Ro/SSA, and anti-La/SSB was much higher in patients with anemia than those without anemia. Anticardiolipin antibodies were most commonly detected in AIHA; the prevalence of IgG and hypocomplementemia in AIHA was much higher in patients without anemia. Abnormal bone marrow changes were observed in two cases with anemia, one with morphological changes in the myeloid, megakaryocytic, and erythroid lineages and one with hypocellularity in the erythroid lineage. Therefore, pSS patients with anemia may be associated with destruction of peripheral mature blood cells, impaired red cells production, and hematopoietic abnormalities due to an immune mechanism, although the concrete pathogenesis is still unclear.

Hyporesponsiveness to erythropoiesis stimulating agents in chronic kidney disease: the many faces of inflammation

The vast majority of patients with chronic kidney disease (CKD) receive an erythropoietic-stimulating agent (ESA) to partially correct the almost inevitable anemia associated with renal insufficiency. However, a minority of CKD patients will require much higher than usual doses of ESA in order to maintain a reasonable hemoglobin concentration. In many instances, these patients will have either an obvious or a clinically unapparent inflammatory process to account for the hyporesponsiveness to ESA replacement therapy. This review focuses on the mechanisms by which inflammation interferes with erythroid marrow function and particularly the new information about the role of inflammatory cytokines and the small peptide, hepcidin, on altered iron metabolism.

Inhibition of p38alpha MAPK disrupts the pathological loop of proinflammatory factor production in the myelodysplastic syndrome bone marrow microenvironment

Myelodysplastic syndromes (MDS) are common causes of ineffective hematopoiesis and cytopenias in the elderly. Various myelosuppressive and proinflammatory cytokines have been implicated in the high rates of apoptosis and hematopoietic suppression seen in MDS. We have previously shown that p38 MAPK is overactivated in MDS hematopoietic progenitors, which led to current clinical studies of the selective p38alpha inhibitor, SCIO-469, in this disease. We now demonstrate that the myelosuppressive cytokines TNFalpha and IL-1beta are secreted by bone marrow (BM) cells in a p38 MAPK-dependent manner. Their secretion is stimulated by paracrine interactions between BM stromal and mononuclear cells and cytokine induction correlates with CD34+ stem cell apoptosis in an inflammation-simulated in vitro bone marrow microenvironment. Treatment with SCIO-469 inhibits TNF secretion in primary MDS bone marrow cells and protects cytogenetically normal progenitors from apoptosis ex vivo. Furthermore, p38 inhibition diminishes the expression of TNFalpha or IL-1beta-induced proinflammatory chemokines in BM stromal cells. These data indicate that p38 inhibition has anti-inflammatory effects on the bone marrow microenvironment that complements its cytoprotective effect on progenitor survival. These findings support clinical investigation of p38alpha as a potential therapeutic target in MDS and other related diseases characterised by inflammatory bone marrow failure.

STAT6-mediated suppression of erythropoiesis in an experimental model of malarial anemia

BACKGROUND

The contribution of pro-inflammatory cytokines to the pathogenesis of malarial anemia has been studied extensively but the roles of Th2 cytokines remain unknown. Here, we investigated the role of signal transducer and activator of transcription (STAT)6-mediated responses in erythropoietic suppression during acute malaria infection in mice.

DESIGN AND METHODS

Naïve and/or erythropoietin-treated wild-type and STAT6(-/-) mice were infected with Plasmodium chabaudi AS (P. chabaudi), and the effects parasitemia, hematologic parameters, erythropoietin receptor, TER119, and CD71 expression, in vitro erythropoietin-stimulated proliferation of splenic erythroid precursors, and serum cytokine levels were analyzed. To explore the role of interleukin-4 in STAT6-dependent erythropoietic suppression, mice were treated in vivo with a monoclonal antibody to interleukin-4 and the effects on parasitemia, hematologic parameters, and cytokine levels were analyzed.

RESULTS

Infected STAT6(-/-) mice developed enhanced reticulocytosis compared to wild-type mice despite higher parasitemia and a similar course of anemia. Enhanced reticulocytosis in infected STAT6(-/-) mice was associated with an increased frequency of late-stage erythroblasts, fewer leukocytes expressing CD71, and increased erythropoietin-stimulated proliferation of splenocytes compared to infected wild-type mice. Interleukin-4-depleted wild-type mice had increased levels of parasitemia and a course of reticulocytosis similar to responses observed in infected STAT6(-/-) mice. Determination of serum cytokine levels in STAT6(-/-) and wild-type mice depleted of interleukin-4 by treatment with mAb revealed significantly lower levels of interferon-gamma compared to control wild-type mice during infection.

CONCLUSIONS

Together, these findings provide evidence for a STAT6-dependent mechanism in mediating erythropoietic suppression during acute blood-stage malaria and indicate a role for interleukin-4 and possibly interferon-gammain STAT6-induced erythropoietic suppression.

Placental growth factor attenuates suppression of erythroid colony formation by interferon

Placental growth factor (PlGF) is a member of the vascular endothelial growth factor family and is associated with inflammation and with pathologic angiogenesis. PlGF is released from marrow erythroid cells, and serum PlGF concentrations have been reported to distinguish sickle cell patients from healthy controls. We observed that erythroid colony forming units (CFU-Es) from homozygous sickle cell (SS) patients are less sensitive to inhibition by rhgammaIFN than those from healthy controls, and the contribution of PlGF to this process was evaluated. At 10-1000-pg/mL concentrations, PlGF neither inhibits nor enhances CFU-E colony formation, and no differences were observed between the responses of SS patients or healthy controls. rhPlGF 100 pg/mL reversed the inhibitory effects of rhgammaIFN on CFU-E colony formation. rhPlGF significantly attenuated rhgammaIFN induction of the Fas ligand in an erythroid cell line (HCD57). Both HCD57 cells and CD36+ human marrow cells express Flt-1, which is a receptor for PlGF. A neutralizing antibody against Flt-1 partially attenuated the IFN-protective effect of rhPlGF, although this effect was not statistically significant. In conclusion, increased PlGF concentrations in the marrow of SS patients may protect erythroid progenitors from cytokine-induced inhibition of colony formation, and it may be a mechanism by which erythropoiesis in sickle cell disease is preserved despite concurrent inflammation.

Dynamic changes in white blood cell counts in uncomplicated Plasmodium falciparum and P. vivax malaria

Total and differential white blood cell (WBC) counts are basic and essential indicators in any type of illness resulting from infection. In malaria, WBC counts are generally characterized as low to normal during treatment. WBC-counts data, before and during treatment with artemisinin derivatives, was gathered for patients with either Plasmodium falciparum or Plasmodium vivax infection (at 28-day follow-up), to investigate dynamic changes in WBC count. We analyzed and compared the WBC counts of 1,310 inpatients presenting with uncomplicated P. falciparum and P. vivax malaria at the Hospital for Tropical Diseases, in Bangkok, Thailand. Before-treatment, a statistically significant negative correlation was found between initial WBC count and highest temperature on admission. Before and during treatment, WBC counts were significantly lower in P. falciparum than P. vivax infection on days 0 and 7, but the numerical difference was small. We also found clinically significantly low WBC counts during the acute stages of both types of malaria, which subsequently normalized by day 28 follow-up. This finding has important clinical implications for the conventional method of estimating parasitemia using an assumed WBC count of 8,000 cells/microL. The most significant finding in our analysis is that WBC counts in acute P. falciparum and P. vivax malaria are significantly lower than previously assumed for estimating malaria-parasite density. However, these abnormalities returned to normal within several weeks after artemisinin-derivative-based treatment.

The anemia of inflammation/malignancy: mechanisms and management

Anemia is a common complication in patients with inflammatory diseases of many kinds, including cancer. The mechanisms that have captured the most attention include cytokine-mediated changes in both the production of and the response to erythropoietin (Epo), as well as important alterations in iron metabolism. The last is brought about by the relatively recently recognized peptide hormone, hepcidin. The availability of recombinant human Epo and its derivatives (known by class as Erythropoietic Stimulating Agents, ESAs) has dramatically changed anemia management in patients with cancer but, in the process, has raised as many issues as have been answered. This chapter reviews the mechanisms resulting in anemia in inflammation, including cancer, and focuses on the controversies around management with the ESAs and the adjuvant use of iron in anemia management.

Oral Administration of Ren-Shen-Yang-Rong-Tang 'Ninjin'yoeito' Protects Against Hematotoxicity and Induces Immature Erythroid Progenitor Cells in 5-Fluorouracil-induced Anemia

The purpose of this study was to investigate the efficacy of four different Japanese and Chinese herbal prescriptions, Ren-Shen-Yang-Rong-Tang (Ninjin'yoeito, NYT), Chai-Hu-Gui-Zhi-Gan-Jiang-Tang (Saikokeishikankyoto, SKKT), Si-Jun-Zi-Tang (Shikunshito, SKT) and Si-Wu-Tang (Shimotsuto, SMT), which are traditionally used for anemia and fatigue, against hematotoxicity in mice treated with 5-fluorouracil (5-FU). NYT 1-100 mg kg(-1) day(-1) injected orally for 7 consecutive days before and after 5-FU injection significantly suppressed reductions in red blood cell, white blood cell and platelet counts in peripheral blood, and accelerated their recovery. Administration of SKKT also produced a slight but significant improvement in 5-FU-induced erythrocytopenia, whereas SMT and SKT could not prevent anemia. Oral injection of NYT also inhibited 5-FU-induced decreases in peripheral reticulocyte and bone marrow cell counts on day 10, and markedly hastened their recovery on day 20, in a dose-dependent manner. Erythroid progenitor colonies, such as colony forming units-erythroid and burst forming units-erythroid, formed by marrow cells from mice treated with 5-FU were significantly increased by oral administration of NYT. These findings suggest that NYT has the potential to protect against hematotoxicity, and also has hematopoietic activity, through stimulation of immature erythroid progenitor cell differentiation.

Anaemia of cancer: an overview of mechanisms involved in its pathogenesis

Anaemia is a common complication in cancer patients. The decrease in haemoglobin is associated with an impaired quality of life, poorer response to therapy and worse prognosis. Numerous factors are involved in the physiopathology of cancer-related anaemia. Some factors such as bleeding, bone marrow infiltration, the effects of chemoradiotherapy and associated nutritional deficiencies are related to the disease itself. In addition, the interaction of the immune system with iron metabolism and erythropoiesis has been shown to be an important factor in the development of anaemia in cancer patients and can be seen in the action of several cytokines on different iron-homeostasis and erythrocyte-cell-production pathways. Some inhibitory cytokines, such as tumour necrosis factor-alpha and interleukin-1, act on the suppression of erythroid precursor cells and erythropoietic production and response; others, such as interleukins 1 and 6 and hepcidin, impair iron metabolism, causing iron to be diverted from erythropoiesis and retained within the reticuloendothelial system. The main mechanisms involved in the development of cancer-related anaemia are discussed in this review.

Hepcidin inhibits in vitro erythroid colony formation at reduced erythropoietin concentrations

The anemia of chronic disease (ACD) results from 3 major processes: slightly shortened red cell survival, impaired reticuloendothelial system iron mobilization, and impaired erythropoiesis. Hepcidin is an acute-phase protein with specific iron regulatory properties, which, along with the anemia seen with increased hepcidin expression, have led many to consider it the major mediator of ACD. However, if hepcidin is the major factor responsible for ACD, then it should also contribute to the impaired erythropoiesis observed in this syndrome. Erythroid colony formation in vitro was inhibited by hepcidin at erythropoietin (Epo) concentrations less than or equal to 0.5 U/mL but not at Epo 1.0 U/mL. At Epo concentrations of 0.3 U/mL, HCD57 erythroleukemia cells exposed to hepcidin exhibit decreased expression of the antiapoptotic protein pBad compared with controls. These studies suggest that hepcidin may contribute to anemia in ACD not only through effects on iron metabolism, but also through inhibition of erythroid progenitor proliferation and survival.

Melatonin corrects reticuloendothelial blockade and iron status in haemodialysed patients

AIM

Treatment of anaemia in haemodialysed patients in the setting of inflammation usually displays high levels of serum ferritin (>800 ng/mL) and low transferrin saturation (TSAT) (<20%) despite i.v. iron supplementation, thus proving iron trapping in the reticuloendothelial system. Melatonin has been reported to reduce cytokine production and, in dialysis patients, to prevent oxidative stress resulting from iron and erythropoietin treatment.

METHOD

In this study, we evaluated a group of 10 patients undergoing haemodialysis who displayed elevated serum ferritin (981 +/- 44.6 ng/mL) and TSAT <20% (15.6 +/- 3.8%) after having received 1.2 g of i.v. iron dextran over a period of 8 weeks. These patients received oral melatonin, 6 mg/day at night for 30 days.

RESULTS

After this treatment, all of them markedly increased TSAT values, reaching 35.5 +/- 6.7% (P < 0.0001 vs basal values). In addition, ferritin values decreased to 754.4 +/- 263.7 ng/mL (P < 0.05), and serum iron dramatically increased in all of the patients under study (42.4 +/- 9.4 vs 109.7 +/- 24.3 microg/dL; P < 0.0001). Values for haematocrit (28.6 +/- 2.7 vs 31.9 +/- 3.57%; P < 0.05) and haemoglobin (9.19 +/- 0.97 vs 10.04 +/- 1.29 g/dL; P < 0.05) were also improved. Measurements were then repeated 2 weeks after melatonin withdrawal, showing an impressive decrease in TSAT (16.4 +/- 5.3%; P < 0.00001) and serum iron (48 +/- 14.7 microg/dL; P < 0.0001) values and an almost significant increase in ferritin values (954.4 +/- 86 ng/mL; P < 0.054).

CONCLUSION

The present study demonstrates that melatonin may strongly correct the reticuloendothelial blockade seen in dialysis patients under an inflammatory status, thus allowing a better management of iron derangements and renal anaemia.