Pathogenesis and treatment of anaemia of chronic disease

Altered iron metabolism, inflammation, transferrin receptors, and ferritin expression in non-small-cell lung cancer

The involvement of iron and inflammation parameters on overall survival in non-small-cell lung cancer (NSCLC) patients was studied. Furthermore, transferrin receptors 1 (TfR1) and ferritin expression in tumor tissue, tumor stroma, and normal lung tissue were analyzed. Iron metabolism and inflammation parameters were determined by automated laboratory measurements at the time of diagnosis. TfR1 and ferritin expression were determined by immuno-histochemical methods. About 50% of patients survived 12 months only. At the time of diagnosis more than half of the patients had anemia and significantly elevated serum ferritin. Iron content of serum ferritin (ICF) was below the reference values in 90% of patients. Furthermore, ICF showed positive correlation with iron metabolic parameters and survival but negative correlation with serum ferritin and ESR. The expression of TfR1 and ferritin in tumor cells was observed in 88% or 62% of patients, respectively. Tumor stroma was TfR1 negative and sporadically ferritin positive. Tumor tissue ferritin expression showed negative correlation with serum iron and hematokrit (Ht), and positive correlation with ferritin, erythrocyte sedimentation rate (ESR), alpha-1 globulin, and alpha-2 globulin. Positive correlation was found between TfR1 expression in tumor tissue and alpha-globulin. The correlation between TfR1/ferritin expression in tumor tissue and ICF or survival was not observed. Therefore, we conclude that elevated serum ferritin in sera of NSCLC patients is the result of inflammation and oxidative stress rather than body iron overload. Higher expression of ferritin in tumor tissue may be the consequence of iron deficiency or local toxicity induced by environmental factors.

Unexplained anemia in the elderly

Among the elderly, anemia occurs with increasing frequency with each advancing decade. Unlike when anemia occurs in younger adults, the cause of anemia in the elderly is oftentimes not readily apparent or attributable to a single cause. However, this commonly observed form of anemia in the elderly (termed unexplained anemia [UA]) can generally be dissected to its root causes, which include renal insufficiency, inflammation, testosterone deficiency, and stem cell proliferative decline. Myelodysplasia (MDS) occurs commonly in this age group but can and should, for both diagnostic and therapeutic considerations, be distinguished from UA.

Role of iron homeostasis in trypanosomiasis-associated anemia

Anemia is a well-established infection-associated immunopathological feature of trypanosomiasis and the degree of the anemia is a reliable indicator of the severity of infection. Since infections with trypanosomes triggers a strong cytokine production and a type I immune response, the trypanosome-elicited anemia may be type I cytokine driven. This type of anemia termed anemia of chronic disease is characterized by an imbalance between erythrophagocytosis and erythropoiesis that is linked to a perturbed iron homeostasis including altered iron recycling by macrophages and iron sequestration. To further unravel the mechanisms underlying trypanosome-elicited anemia the expression profile of genes involved in erythrophagocytosis, uptake of iron-containing complexes and iron homeostasis was performed during the acute and chronic phase of experimental Trypanosoma brucei infections in a murine model. The results suggest that liver-associated erythrophagocytosis mediated by cytokine-activated macrophages (M1 cells) is the most likely main initiating event of aggressive anemia during the acute phase of infection. Persistence of strong type I cytokine production during the chronic phase of infection leads to hyper-activated M1 cells and a more progressive anemia. RT-PCR analysis of liver tissue demonstrates a strong increase of cell surface receptors involved in uptake of RBC and iron-containing compounds. For genes involved in iron processing we found an increase of ferroportin-1 (FPN-1), transferrin (Tf) and ceruloplasmin (CP) only in the acute phase, suggesting that export of iron is hampered in the chronic phase of infection. Our results suggest that in the chronic phase of trypanosomiasis, the iron-processing pathway is skewed towards iron sequestration, as evidenced by increased ferritin expression, while enhanced uptake of RBC/iron-containing compounds is maintained.

Murine Models of Anaemia of Inflammation: Extramedullary Haematopoiesis Represents a Species Specific Difference to Human Anaemia of Inflammation That Can Be Eliminated by Splenectomy

In contrast to humans, mice physiologically exhibit extramedullary haematopoiesis in the spleen. In spite of this crucial species specific difference not much is known about the contribution of extramedullary haematopoiesis to overall erythropoiesis in models of anaemia of inflammation (AI). The objective of this study is to characterize murine AI with respect to extramedullary haematopoiesis and to develop a model more closely resembling human AI. Three different models of AI [caecal ligation and puncture (CLP), collagen induced arthritis (CIA) and DSS induced chronic colitis (DSSC)] were characterized with respect to red blood parameters, iron metabolism and extramedullary haematopoiesis. Arthritic animals were splenectomised to prevent extramedullary haematopoiesis. Anaemia caused by systemic inflammation was found in all three models. Splenic extramedullary haematopoiesis was markedly increased as reflected by increment in spleen weights and increase of the red pulp resulting in increased reticulocyte counts. Splenectomised arthritic animals did not show increased reticulocyte counts indicating that most of the reticulocytes were produced in the spleen. Our results demonstrate that murine AI differs from human AI with respect to increased splenic extramedullary haematopoiesis. Our data demonstrate that induction of AI in splenectomised mice represents a good way to model human AI.

Influence of blood transfusions and preoperative anemia on long-term survival in patients operated for non-small cell lung cancer

It has been postulated that transfusions have immunosuppressive effects that promote tumor growth and metastasis. Moreover perioperative anemia is considered an independent prognostic factor on outcome in patients operated for malignancy. We evaluated the influence of red blood cell (RBC) transfusions and perioperative anemia on survival in non-small cell lung carcinoma (NSCLC) patients. From 1999 through 2005, 331 consecutive patients, male/female=295/36 (mean age 64+/-9 years), who underwent radical surgery for NSCLC were prospectively enrolled in this cohort and followed up for a mean of 27.2 months. The overall survival of patients was analyzed in relation to RBC transfusions and perioperative anemia. These parameters were analyzed in the whole cohort of patients and separately for stage I patients. Patients were divided according to perioperative transfusion, into Group A (transfused) and Group B (non-transfused) and according to the preoperative haemoglobin (Hb) level into Group 1(Hb<12g/dl) and Group 2(Hb> or =12g/dl), respectively. The overall transfusion rate was 25.7%. Univariate analysis showed that in the whole cohort of patients overall survival was significantly shorter in Group A (mean 33.6 months, 5-year survival 25.1%) compared to Group B (mean 48.0 months, 5-year survival 37.3%) (p=0.001). It also showed that patients with preoperative Hb level <12g/dl (Group 1), (mean of 33.0 months, 5-year survival 21.3%) had shorter survival compared to Group 2 patients (mean 49.3 months and 5-year survival 40.0%), respectively (p=0.002). Multivariate analysis in the whole cohort of patients showed that preoperative anemia was an independent risk factor for survival while RBC transfusion was not. In particular for stage I patients, it was shown that RBC transfusion was an independent prognostic factor for long-term survival as detected by multivariate analysis (p=0.043), while anemia was not. RBC transfusions affect adversely the survival of stage I NSCLC patients, while do not exert any effect on survival of patients with surgically resectable more advanced disease, where preoperative anemia is an independent negative prognostic factor. These findings indicate that RBC transfusion might exert an immunomodulatory effect on patients with early disease while in more advanced stages this effect is not apparent.

Anemia as an independent predictor of perioperative and long-term cardiovascular outcome in patients scheduled for elective vascular surgery

Anemia is common in patients scheduled for vascular surgery and is a risk factor for adverse cardiac outcome. However, it is unclear whether this is an independent risk factor or an expression of underlying co-morbidities. In total, 1,211 patients (77% men, 68 +/- 11 years of age) were enrolled. Anemia was defined as serum hemoglobin levels <13 g/dl for men and <12 g/dl for women and was divided into tertiles to compare mild (men 12.2 to 13.0, women 11.2 to 12.0), moderate (men 11.0 to 12.1, women 10.2 to 11.1), and severe (men 7.2 to 11.0, women 7.5 to 10.1) anemia with nonanemia. Outcome measurements were 30-day and 5-year major adverse cardiac events (MACEs; cardiac death or myocardial infarction). All risk factors were noted. Multivariable logistic and Cox regression analyses were used, adjusting for all cardiac risk factors, including heart failure and renal disease. Data are presented as hazard ratios with 95% confidence intervals. In total, 74 patients (6%) had 30-day MACEs and 199 (17%) had 5-year MACEs. Anemia was present in 399 patients (33%), 133 of whom had mild anemia, 133 had moderate anemia, and 133 had severe anemia. Presence of anemia was associated with renal dysfunction, diabetes, and heart failure. After adjustment for all clinical risk factors, 30-day hazard ratios for a MACE per anemia group were 1.8 for mild (0.8 to 4.1), 2.3 for moderate (1.1 to 5.4), and 4.7 for severe (2.6 to 10.9) anemia, and 5-year hazard ratios for MACE per anemia group were 2.4 for mild (1.5 to 4.2), 3.6 for moderate (2.4 to 5.6), and 6.1 for severe (4.1 to 9.1) anemia. In conclusion, the presence and severity of preoperative anemia in vascular patients are significant predictors of 30-day and 5-year cardiac events, regardless of underlying heart failure or renal disease.

Pathogenesis of the systemic inflammatory syndrome and acute lung injury: role of iron mobilization and decompartmentalization

Changes in iron homeostatic responses routinely accompany infectious or proinflammatory insults. The systemic inflammatory response syndrome (SIRS) and the development of acute lung injury (ALI) feature pronounced systemic and lung-specific alterations in iron/heme mobilization and decompartmentalization; such responses may be of pathological significance for both the onset and progression of acute inflammation. The potential for excessive iron-catalyzed oxidative stress, altered proinflammatory redox signaling, and provision of iron as a microbial growth factor represent obvious adverse aspects of altered in vivo iron handling. The release of hemoglobin during hemolytic disease or surgical procedures such as those utilizing cardiopulmonary bypass procedures further impacts on iron mobilization, turnover, and storage with associated implications. Genetic predisposition may ultimately determine the extent to which SIRS and related syndromes develop in response to such changes. The design of specific therapeutic interventions based on endogenous stratagems to limit adverse aspects of altered iron handling may prove of therapeutic benefit for the treatment of SIRS and ALI.

Interferon-gamma mediates suppression of erythropoiesis but not reduced red cell survival following CpG-ODN administration in vivo

OBJECTIVE

Cytokines released during inflammatory processes have been proposed to play a central role in mediating mechanism(s) leading to anemia. Here, we used CpG-ODN to investigate the effects of a pro-inflammatory response on the pathophysiological processes leading to anemia.

METHODS

Naïve and erythropoietin (EPO)-treated mice were injected for 2 days with 100 microg CpG-ODN or control ODN and the effects on the course of red blood cell (RBC) and reticulocyte counts, RBC turnover, and EPO-stimulated maturation of erythroid cells were analyzed. To study the effect of CpG-ODN on erythroid cell maturation in vitro, we obtained primary EPO-responsive cells by treating mice with thiamphenicol (15 mg/g body weight).

RESULTS

CpG-ODN-treated mice developed anemia, which persisted for 5 days and was associated with a 50% reduction in EPO-stimulated differentiation of EPOR+ cells to TER119+ erythroblasts. CpG-ODN-induced suppression required accessory cells, including antigen presenting cells, which activated other cells to produce pro-inflammatory cytokines. In vitro neutralization of IFN-gamma, but not IL-12, TNF-alpha, IFN-alpha, IL-1alpha, or IL-1beta, abrogated the erythropoietic suppression induced by CpG-ODN. The anemia observed in CpG-ODN-treated mice was also associated with reduced RBC survival in vivo, as demonstrated by a sevenfold to eightfold higher turnover of biotinylated RBC compared to control ODN-treated mice. In vivo IFN-gamma neutralization confirmed that IFN-gamma contributed to erythropoietic suppression but not reduced RBC survival.

CONCLUSIONS

Together, these results demonstrate that CpG-ODN anemia is associated with suppressed erythropoiesis and decreased RBC survival. Importantly, CpG-ODN-induced IFN-gamma was found to be the major factor mediating erythropoietic suppression but not decreased RBC survival.

An extended maintenance dosing regimen of epoetin alfa 80,000 U every 3 weeks in anemic patients with cancer receiving chemotherapy

BACKGROUND

The purpose of this study was to evaluate the safety and efficacy of epoetin alfa (EPO) at an initial dose of 60,000 Units (U) once weekly (QW) followed by extended dosing of 80,000 U every 3 weeks (Q3W) in patients with chemotherapy-induced anemia (CIA).

MATERIALS AND METHODS

Anemic patients (hemoglobin [Hb] < or = 11 g/dl) receiving Q3W chemotherapy for nonmyeloid malignancy were enrolled in this prospective, open-label, single-arm study to receive EPO 60,000 U subcutaneously (SC) QW (initial dosing phase [IDP]) until a target Hb level of 12 g/dl was reached (maximum 12 weeks). Patients who achieved an Hb level of 12 g/dl at any point during the IDP then entered the extended dosing phase (EDP; EPO 80,000 U SC Q3W). Maximum study duration (IDP + EDP) was 24 weeks. The primary endpoint was the proportion of patients achieving a hematopoietic response (Hb increase > or = 2 g/dl from baseline or Hb > or = 12 g/dl) during the IDP.

RESULTS

One hundred fifteen patients were enrolled. During the IDP, 76% (84/110) of patients achieved a hematopoietic response, and 15% (17/115) received red blood cell (RBC) transfusion. Sixty-three percent (73/115) of patients entered the EDP, and 88% (64/73) of these patients maintained a mean Hb level > 11.0 and < or =13.0 g/dl. Two of 73 patients received RBC transfusion during the EDP. Adverse events were consistent with the underlying disease and chemotherapy treatment.

CONCLUSION

These results suggest that initiation of EPO 60,000 U SC QW is effective in the treatment of CIA and that EPO 80,000 U SC Q3W can be an effective extended dosing option.

Prognostic value of reduced kidney function and anemia in patients with chronic heart failure

OBJECTIVES

The present study aimed to evaluate the prognostic value of B-type natriuretic peptide (N-proBNP), renal dysfunction and anemia in chronic heart failure (CHF) patients.

METHODS

We analyzed data from a prospective cohort of 153 patients (mean age 64 years) with CHF referred to our hospital center. Clinical, echocardiographic and laboratory data were drawn during hospital recovery in all patients. Kidney dysfunction was defined as a glomerular filtration rate (GFR) < 60 ml/min and anemia as a hematocrit < 35%. After discharge, patients attended the outpatient clinic of our institution.

RESULTS

Kidney dysfunction was diagnosed in 37% of cases, whereas anemia was present in 25% of patients. During follow-up (median time 456 days), 32 patients died. Multivariate Cox proportional hazard model revealed that N-proBNP [hazard ratio (HR) = 1.002; P < 0.001] and GFR (HR = 0.972; P < 0.005) were significant predictors for mortality after adjustment for confounding variables. Kaplan-Maier analysis demonstrated a progressive decrease in survival from lowest to highest tertiles of N-proBNP values (log rank = 28.7; P < 0.001) and from higher to lower GFR values (log rank = 5.63; P < 0.01). Moreover, parametric survival analysis by the Weibull model demonstrated that the estimated probability of survival adjusted for N-proBNP values was higher in patients with GFR > or = 60 ml/min than in those with GFR < 60 ml/min (P < 0.001).

CONCLUSION

Increased N-proBNP and decreased kidney function, but not anemia, are independent risk factors for mortality in patients with CHF.

Anemia is associated with abdominal aortic aneurysm (AAA) size and decreased long-term survival after endovascular AAA repair

OBJECTIVE

Anemia is a common comorbid condition in various inflammatory states and an established predictor of mortality in patients with chronic heart failure, ischemic heart disease, and end-stage renal disease. The present study of patients with abdominal aortic aneurysm (AAA) undergoing endovascular repair (EVAR) assessed the relationships between baseline hemoglobin concentration and AAA size, as well as anemia and long-term survival.

METHODS

Between March 1994 and November 2006, 711 patients (65 women, mean age 75.8 +/- 7.8 years) underwent elective EVAR. Anemia was defined as a hemoglobin level <13 g/dL in men and <12 g/dL in women. Post-EVAR mean follow-up was 48.3 +/- 32.0 months. Association of hemoglobin level with AAA size was assessed with multiple linear regression. Mortality was determined with use of the internet-based Social Security Death Index and the electronic hospital record. Kaplan-Meier survival curves of anemic and nonanemic patient groups were compared by the log-rank method. Multivariable logistic regression models were used to determine the influence of anemia on vital status after EVAR.

RESULTS

A total of 218/711 (30.7%) of AAA patients undergoing EVAR had anemia at baseline. After adjustment for various risk factors, hemoglobin level was inversely related to maximum AAA diameter (beta: - .144, 95%-CI: -1.482 - .322, P = .002). Post-EVAR survival was 65.5% at 5 years and 44.4% at 10 years. In long-term follow-up, survival was significantly lower in patients with anemia as compared to patients without anemia (P < .0001 by log-rank). Baseline hemoglobin levels were independently related to long-term mortality in multivariable Cox regression analysis adjusted for various risk factors (adjusted HR: 0.866, 95% CI: .783 to .958, P = .005). Within this model, statin use (adjusted HR: .517, 95% CI: .308 to .868, P = .013) was independently related to long-term survival, whereas baseline AAA diameter (adjusted HR: 1.022, 95% CI: 1.009 to 1.036, P = .001) was an independently associated with increased mortality.

CONCLUSIONS

Baseline hemoglobin concentration is independently associated with AAA size and reduced long-term survival following EVAR. Thus, the presence or absence of anemia offers a potential refinement of existing risk stratification instruments.

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.

Chronic anemia and fatigue in elderly patients: results of a randomized, double-blind, placebo-controlled, crossover exploratory study with epoetin alfa

OBJECTIVES

To evaluate the effect of epoetin alfa treatment on hemoglobin (Hb), fatigue, quality of life (QOL), and mobility in elderly patients with chronic anemia.

DESIGN

An exploratory, 32 week, randomized, double-blind, crossover treatment trial.

PARTICIPANTS

Sixty-two community-dwelling individuals aged 65 and older with chronic anemia (Hb < or =11.5 g/dL).

INTERVENTION

Subcutaneous epoetin alfa or placebo weekly for 16 weeks (Phase I) with crossover to the opposite treatment (Phase II).

MEASUREMENTS

Hb and QOL scores from the Functional Assessment of Chronic Illness Therapy (FACIT) measurement system. Mobility was assessed as a secondary outcome using the Timed Up and Go (TUG) test.

RESULTS

Of the 62 subjects enrolled, complete data were analyzed for 58 in Phase I and 54 participants in Phase II. Of those enrolled, most were African American (95%) and female (85%) and had multiple comorbidities and a mean age+/-standard deviation of 76.1+/-7.2. Mean baseline Hb was 10.5+/-0.9 g/dL (7.3-11.5). In Phase I, 67% of those taking epoetin alfa, and in Phase II, 69% of those taking epoetin alfa had an increase in Hb of more than 2 g/dL, significantly more than those taking placebo (P<.001). Similarly, elderly participants significantly improved on the fatigue and anemia subscales of the FACIT across phases (all P<.05). No significant differences were found between treatment and placebo on TUG scores. Epoetin alfa was well tolerated.

CONCLUSION

In this trial involving predominantly older African-American women with anemia, a direct relationship existed between increases in Hb during epoetin alfa therapy and improvements in fatigue and QOL.

Toxicity as a result of immunostimulation by biologics

The immune system has evolved highly effective mechanisms of surveillance and defense against foreign pathogens, and is also thought to act in surveillance and suppression of cancer. Thus, a predominant goal of immune system-based therapies is to normalize or enhance the host immune response in the areas of infectious disease and oncology. This review considers general approaches used for therapeutic immunostimulation, alterations in immune response mechanisms that occur with these treatments and the syndromes that commonly arise as a result of these changes. Because nonclinical studies of these therapies are conducted in animal models as the basis for predicting potential human toxicities, this review also considers the value of nonclinical testing to predict human toxicity.

Hepcidin in Anemia and Inflammation in Chronic Kidney Disease

Maintaining the correct iron balance is crucial for health. Our understanding of the molecular control of iron metabolism has increased dramatically over the past 5 years due to the discovery of hepcidin. This is a circulating antimicrobial peptide mainly synthesized in the liver, which has been recently proposed as a factor regulating the uptake of dietary iron and its mobilization from macrophages and hepatic stores. Inflammation causes an increase of production of hepcidin, which is a potent mediator of anemia of chronic diseases. Anemia in chronic kidney disease is mainly due to erythropoietin deficiency but these patients often have a chronic inflammatory state. The aim of this review is to summarize the current knowledge dealing with a possible role of hepcidin in iron metabolism and its regulation, particularly in kidney disease. In addition, current methods of determination of hepcidin are reviewed.

Disseminated tuberculosis: a 10-year experience in a medical center

Disseminated tuberculosis remains a diagnostic challenge because the presentations are nonspecific. In the current retrospective study we describe the clinical characteristics and outcome of disseminated tuberculosis. From January 1995 to December 2004, patients with culture-confirmed tuberculosis who fulfilled the criteria for disseminated tuberculosis were selected and their medical records reviewed. Their clinical isolates were genotyped. Of the 3058 patients with culture-confirmed tuberculosis, 164 (5.4%) had disseminated disease; 14.0% of patients had acquired immunodeficiency syndrome. The most common radiographic finding was miliary lung lesions (47.0%); 31.1% of patients died at the end of the study. Poor prognostic factors included hypoalbuminemia, hyperbilirubinemia, renal insufficiency, and delayed antituberculosis treatment. Clinical findings suggestive of disseminated tuberculosis were miliary lung lesions, serum ferritin >1000 microg/L, infiltrative liver disease, and adjusted calcium >2.6 mmol/L. Simultaneously performing mycobacterial culture and histopathologic examination of bone marrow biopsy was more sensitive and faster than just performing mycobacterial blood culture in diagnosing disseminated tuberculosis. Of the 64 preserved Mycobacterium tuberculosis isolates, 47 (73.4%) were clustered and 27 (42.2%) were Beijing family. Since prognosis was worse in patients with delayed treatment, a high index of suspicion is required, especially in those with clinical findings suggestive of disseminated tuberculosis.

The prevalence and evolution of anemia associated with tuberculosis

Tuberculosis (TB) may produce abnormalities in the peripheral blood, including anemia. However, the evolution of TB-associated anemia with short-term combination anti-TB chemotherapy has not been well elucidated. The aim of this study was to characterize TB-associated anemia by clarifying its prevalence, characteristics, and evolution, through involving large numbers of patients with TB. The medical records of adult patients with TB diagnosed between June 2000 and May 2001 were reviewed. Among 880 patients with TB, 281 (31.9%) had anemia on diagnosis of TB, however, the hemoglobin concentration was less than 10 g/dL in only 45 patients (5.0%). Anemia was more frequently associated with the female and old age. Good treatment response, young age (< or =65 yr-old) and initial high hemoglobin were the predictive factor for resolution of anemia. In 202 patients with anemia (71.9%), anemia was normocytic and normochromic. During or after anti-TB treatment, anemia was resolved in 175 (64.6%) out of 271 patients without iron intake. The mean duration of resolution from the initiation of anti-TB treatment was 118.8+/-113.2 days. In conclusion, anemia is a common hematological abnormality in patients with TB and close observation is sufficient for patients with TB-associated anemia, because TB-associated anemia is usually mild and resolves with anti-TB treatment.

Etiology of anemia in patients with advanced heart failure

OBJECTIVES

We prospectively investigated the causes of anemia in patients with advanced congestive heart failure (CHF).

BACKGROUND

Anemia is common in patients with advanced CHF, and its etiology is generally considered to be multifactorial. However, despite its importance, precise information is lacking regarding the prevalence of putative etiologic factors.

METHODS

Patients who were hospitalized for decompensated advanced CHF and who were stabilized after their initial treatment underwent evaluation of "clinically significant" anemia, defined as a hemoglobin content <12 g/dl for men and <11.5 g/dl for women. Patients with a serum creatinine concentration >3 mg/dl or patients with concurrent diseases that are known to cause anemia were not included. The initial evaluation included measurements of vitamin B(12), folic acid, thyroid-stimulating hormone, erythropoietin, lactate dehydrogenase, Coombs test, multiple fecal occult tests, and bone marrow aspiration. Patients without diagnosis by these methods underwent red cell mass measurement with (51)Cr assay.

RESULTS

The mean age of the 37 patients was 57.9 +/- 10.9 years and mean left ventricular ejection fraction 22.5 +/- 5.9%. Iron deficiency anemia was confirmed by bone marrow aspiration in 27 patients (73%), 2 patients (5.4%) had dilutional anemia, and 1 patient (2.7%) had drug-induced anemia. No specific cause was identified in 7 patients (18.9%) who were considered to have "anemia of chronic disease." Serum ferritin for the iron-deficient patients was not a reliable marker of iron deficiency in this population.

CONCLUSIONS

In this group of patients, iron deficiency was the most common cause of anemia. The iron status of patients with end-stage chronic CHF should be thoroughly evaluated and corrected before considering other therapeutic interventions.

Molecular and clinical aspects of iron homeostasis: From anemia to hemochromatosis

The discovery in recent years of a plethora of new genes whose products are implicated in iron homeostasis has led to rapid expansion of our knowledge in the field of iron metabolism and its underlying complex regulation in both health and disease. Abnormalities of iron metabolism are among the most common disorders encountered in practical medicine and may have significant negative impact on physical condition and life expectancy. Basic insights into the principles of iron homeostasis and the pathophysiological and clinical consequences of iron overload, iron deficiency and misdistribution are thus of crucial importance in modern medicine. This review summarizes our current understanding of human iron metabolism and focuses on the clinically relevant features of hereditary and secondary hemochromatosis, iron deficiency anemia, anemia of chronic disease and anemia of critical illness. The interconnections between iron metabolism and immunity are also addressed, in as much as they may affect the risk and course of infections and malignancies.

Cytokine gene expression in Walker 256: A comparison of variants A (aggressive) and AR (regressive)

Two variants of this Walker 256 tumor have been previously reported as Walker 256 A and variant AR. The variant A has more aggressive property than variant AR and can induce systemic effects such as anorexia, sodium and water retention, followed by weight loss and death. The mechanisms involved in enhancing tumor regression and progression in this model are still incompletely understood. In the present study, serum and spleen mononuclear cells and tumor cells from animals inoculated with variants A and AR, were isolated to investigate the TGF-beta, IL-12, IFN-gamma and TNF-alpha and relationship with anemia, weight of animals, weight of spleen, volume of tumor and osmotic fragility compared with controls inoculated with Ringer Lactate. Results demonstrate that the group inoculated with variant A, compared to variant AR, shows high levels of TGF-beta gene expression in both tumor tissue and spleen cells, no expression of IFN-gamma and a progressive and higher levels of IL-12 in tumor tissue without inflammatory infiltrate visualized by optical microscopy. These results suggest that the aggressively of variant A is relate to cytokine modulation, facilitating the growth and escape of tumor cells. Furthermore, IL-12 seems to be constitutively expressed in both tumor lineage A and AR.

Tumour necrosis factor alpha causes hypoferraemia and reduced intestinal iron absorption in mice

Cytokines are implicated in the anaemia of chronic disease by reducing erythropoiesis and increasing iron sequestration in the reticuloendotheial system. However, the effect of cytokines, in particular TNFalpha (tumour necrosis factor alpha), on small bowel iron uptake and iron-transporter expression remains unclear. In the present study, we subjected CD1 male mice to intraperitoneal injection with TNFalpha (10 ng/mouse) and then examined the expression and localization of DMT1 (divalent metal transporter 1), IREG1 (iron-regulated protein 1) and ferritin in duodenum. Liver and spleen samples were used to determine hepcidin mRNA expression. Changes in serum iron and iron loading of duodenum, spleen and liver were also determined. We found a significant (P<0.05) fall in serum iron 3 h post-TNFalpha exposure. This was coincident with increased iron deposition in the spleen. After 24 h of exposure, there was a significant decrease in duodenal iron transfer (P<0.05) coincident with increased enterocyte ferritin expression (P<0.05) and re-localization of IREG1 from the basolateral enterocyte membrane. Hepatic hepcidin mRNA levels remained unchanged, whereas splenic hepcidin mRNA expression was reduced at 24 h. In conclusion, we provide evidence that TNFalpha may contribute to anaemia of chronic disease by iron sequestration in the spleen and by reduced duodenal iron transfer, which seems to be due to increased enterocyte iron binding by ferritin and a loss of IREG1 function. These observations were independent of hepcidin mRNA levels.

Hemoglobin Level, Chronic Kidney Disease, and the Risks of Death and Hospitalization in Adults With Chronic Heart Failure

Background— Previous studies have associated reduced hemoglobin levels with increased adverse events in heart failure. It is unclear, however, whether this relation is explained by underlying kidney disease, treatment differences, or associated comorbidity.

Methods and Results— We examined the associations between hemoglobin level, kidney function, and risks of death and hospitalization in persons with chronic heart failure between 1996 and 2002 within a large, integrated, healthcare delivery system in northern California. Longitudinal outpatient hemoglobin and creatinine levels and clinical and treatment characteristics were obtained from health plan records. Glomerular filtration rate (GFR; mL · min −1 · 1.73 m −2 ) was estimated from the Modification of Diet in Renal Disease equation. Mortality data were obtained from state death files; heart failure admissions were identified by primary discharge diagnoses. Among 59 772 adults with heart failure, the mean age was 72 years and 46% were women. Compared with that for hemoglobin levels of 13.0 to 13.9 g/dL, the multivariable-adjusted risk of death increased with lower hemoglobin levels: an adjusted hazard ratio (HR) of 1.16 and 95% confidence interval (CI) of 1.11 to 1.21 for hemoglobin levels of 12.0 to 12.9 g/dL; HR, 1.50 and 95% CI, 1.44 to 1.57 for 11.0 to 11.9 g/dL; HR, 1.89 and 95% CI, 1.80 to 1.98 for 10.0 to 10.9; HR, 2.31 and 95% CI, 2.18 to 2.45 for 9.0 to 9.9; and HR, 3.48 and 95% CI, 3.25 to 3.73 for <9.0 g/dL. Hemoglobin levels ≥17.0 g/dL were associated with an increased risk of death (adjusted HR, 1.42; 95% CI, 1.24 to 1.63). Compared with those with a GFR ≥60 mL · min −1 · 1.73 m −2 , persons with a GFR <45 mL · min −1 · 1.73 m −2 had an increased mortality risk: adjusted HR, 1.39 and 95% CI, 1.34 to 1.44 for 30 to 44; HR, 2.28 and 95% CI, 2.19 to 2.39 for 15 to 29; HR, 3.26 and 95% CI, 3.05 to 3.49 for <15; and HR, 2.44 and 95% CI, 2.28 to 2.61 for those on dialysis. Relations were similar for the risk of hospitalization. The findings did not differ among patients with preserved or reduced systolic function, and hemoglobin level was an independent predictor of outcomes at all levels of kidney function.

Conclusions— Very high (≥17 g/dL) or reduced (<13 g/dL) hemoglobin levels and chronic kidney disease independently predict substantially increased risks of death and hospitalization in heart failure, regardless of the level of systolic function. Randomized trials are needed to evaluate whether raising hemoglobin levels can improve outcomes in chronic heart failure.

A preliminary study of placental umbilical cord whole blood transfusion in under resourced patients with malaria in the background of anaemia

Background

Malaria is an annual killer of over one million people globally and its essential co-morbidity is anaemia. Cord blood, because of its rich mix of foetal and adult haemoglobin, high platelet and WBC counts, hypo-antigenic nature, altered metabolic profile and high affinity for oxygen as well as its anti-malarial effect, is an ideal choice in malaria with anaemia, necessitating blood transfusion.

Methods

This paper presents an alternative protocol for fresh whole blood/packed cell transfusion from the hospital's biological waste resources, i.e., the placenta, after the birth of a healthy baby from a healthy mother. This collected blood was routinely transfused to patients admitted in our hospital with severe anaemia in the background of confirmed malaria. 94 units of placental umbilical cord whole blood were collected after lower uterine caesarean section (LUCS) from consenting mothers (from 1^st April 1999 to April 2005), and safely transfused to 39 informed, consenting patients (age varying from 8 to 72 years). The collected volume of cord blood from each placenta (Unit) varied from 52 ml to 143 ml, with a mean packed cell volume of 48.9 ± 4.1 SD and a mean haemoglobin concentration of 16.4 Gm percent ± 1.6 Gm percent SD. The blood was immediately transfused after following the standard adult blood transfusion protocol of screening and cross-matching between the donor and the recipient. On occasion, the collected cord blood was preserved in the refrigerator, if no volunteer was readily available, and transfused within 72 hours of collection.

Results

Cord blood transfusion was tested on twenty two patients infected with Plasmodium falciparum and 17 patients with Plasmodium vivax. For inclusion in this study, the patient's plasma haemoglobin had to be 8 gm percent or less (the pre-transfusion haemoglobin in the malaria-infected patients in this series varied from 5.4 gm/dl to 7.9 gm/dl). The rise of haemoglobin within 72 hours of two units of freshly collected cord blood transfusion was 0.5 gm/dl to 1.6 gm/dl. Each patient received two to six units of freshly collected cord blood transfusion (two units at a time), depending on availability and compatibility. No clinical immunological or non-immunological reaction has been encountered in this series.

Conclusion

Properly screened cord blood is safe for transfusion, in victims of severe malarial anaemia who need transfusion support.

IFNgammaR2 trafficking tunes IFNgamma-STAT1 signaling in T lymphocytes

Ligand-dependent downregulation of the interferon gamma receptor signaling chain (IFNgammaR2) has always been seen as a key mechanism for shielding T lymphocytes from the antiproliferative effects of the IFNgamma-signal transducer and activator of transcription 1 (STAT1) pathway. Now, however, a ligand-independent mechanism of IFNgammaR2 internalization is emerging as a more general way of limiting IFNgamma-STAT1 signaling in T cells, with insulin-like growth factor-1 (IGF-1) and iron as the main players. Here, we review the array of immunomodulatory effects exerted by these two factors on different cell types involved in the immune response; these effects suggest that an inflammatory environment generates signals that favor IFNgammaR2 cell-surface accumulation and IFNgamma-induced apoptosis in T cells, whereas an anti-inflammatory environment promotes IFNgammaR2 internalization and induces T cell unresponsiveness to IFNgamma signaling.

Modulation of Iron Availability at the Host-Pathogen Interface in Phagocytic Cells

This review summarizes recent data on iron metabolism in macrophages, with a special emphasis on possible bacteriostatic and bactericidal consequences for intracellular pathogens. It includes the role of biological chelators and transporters in normal macrophage physiology and antimicrobial defense. Iron is an essential metal cofactor for many biochemical pathways in mammals. However, excess iron promotes the formation of cytotoxic oxygen derivatives so that systemic iron levels must be tightly regulated. The mechanism of iron recycling by macrophages including iron efflux from erythrocyte-containing phagosomes, iron release from macrophages, and entry into the transferrin (Tf) cycle remain poorly understood. Ferroportin expression in the liver, spleen, and bone marrow cells appears to be restricted to macrophages. Mutant mice bearing a conditional deletion of the ferroportin gene in macrophages show retention of iron by hepatic Kupffer cells and splenic macrophages. Hepcidin is induced by lipopolysaccharide (LPS) in mouse spleens and splenic macrophage in vitro and appears to mediate the LPS-induced down-regulation of ferroportin in the intestine and in splenic macrophages, suggesting that inflammatory agents may regulate iron metabolism through modulation of ferroportin expression. The host transporter Nramp1 may compete directly with bacterial divalent-metal transport systems for the acquisition of divalent metals within the phagosomal space. The ultimate outcome of these competing interactions influences the ability of pathogens to survive and replicate intracellularly. This seems particularly relevant to the Salmonella, Leishmania, and Mycobacterium spp., in which inactivating mutations in Nramp1 abrogate the natural resistance of macrophages to these pathogens.

Benefits and risks of iron therapy for chronic anaemias

Iron is used widely for the treatment of anaemias with iron-restricted erythropoiesis. This intervention can be both beneficial and detrimental depending on the type of the underlying process. While in iron deficiency anaemia (IDA), the most frequent anaemia in the world, iron is the therapy of choice, this intervention can be harmful in the anaemia of chronic disease or anaemia associated with renal failure, the most common anaemias in hospitalized adult patients in Western countries. Iron is able to negatively affect cell-mediated immune effector mechanisms directed against invading microorganisms and tumour cells while at the same time, as an essential nutrient, it can stimulate the proliferation of these unwanted cells. In addition, iron catalyses the formation of toxic radicals leading to tissue damage or the promotion of cardiovascular events. Thus, it is essential to correctly diagnose the precise cause of anaemia and to consider the benefits and hazards of targeted iron therapy.

Aging of red blood cells and impaired erythropoiesis following prolonged administration of dichloromethylene diphosphonate containing liposomes in rats

OBJECTIVES

To investigate whether macrophage-depleted rats may serve as a model for studying red blood cell (RBC) aging.

METHODS

Rats were macrophage-depleted by 4 weekly injections of dichloromethylene diphosphonate-containing liposomes (Cl2MDP-CL). The macrophage content of spleens and bone marrows (BMs) was investigated by immunohistochemistry and light microscopy and by flow cytometry, respectively, after staining with macrophage-specific monoclonal antibodies. In addition, the ultrastructure of residual BM macrophages and their ability to phagocytose zymosan was studied. BM was also studied for apoptosis (by the TUNEL reaction) and for erythroid progenitor cell content. Furthermore, RBC indices, morphology, life span (by 51Cr labeling) and aging features (MCV, density, 4.1a/4.1b membrane protein ratio, anti-spectrin IgG binding, microvesiculation) were investigated. Serum TNF-alpha, iron, total iron-binding capacity (TIBC) and ferritin were also determined.

RESULTS

Prolonged treatment with Cl2MDP-CL caused an almost complete depletion of macrophages in the spleen and a 58% reduction of those in the BM; the residual BM macrophages were activated as judged by their ultrastructure and phagocytic capacity in vitro. These alterations were accompanied by an increase in RBC life span and age-related RBC changes, as well as by mild anemia associated with a reduced reticulocyte count, reduced BM erythroid progenitors, increased numbers of apoptotic cells in the BM, low serum iron, high TIBC and increased serum TNF-alpha levels.

CONCLUSIONS

Rats subjected to prolonged macrophage depletion showed an increased prevalence of senescent RBC in the circulation due to their impaired clearance by macrophages. Hence, these animals provide a model system in which mechanisms of RBC aging can be delineated. They also showed impaired erythropoiesis, presumably related to a reduction in BM macrophages and increased production of proinflammatory cytokines by residual activated marrow macrophages and other cells.

Novel tissue remodelling roles for human recombinant erythropoietin

rHuEPO (recombinant human erythropoietin) is a haemopoietic growth factor and a primary regulator of erythropoiesis that is used for the treatment of chronic anaemia associated with RA (rheumatoid arthritis). Erythropoietin also appears to modulate a broad array of cellular processes, including progenitor stem-cell development, cellular integrity, angiogenesis and oxidative damage. These diverse activities suggest the exciting possibility of multiple roles for rHuEPO therapy in a variety of disorders other than RA, including cerebral ischaemia, myocardial infarction, chronic congestive heart failure and cancer. Thus it appears that rHuEPO may be a pleiotropic agent, capable of influencing tissue remodelling independently of its established erythropoietic role. Whereas these effects may be largely beneficial, dose-related side effects could have implications for the safe therapeutic use of rHuEPO and its illegal use as a performance-enhancing agent in endurance sports.

[Erythrophagocytosis and recycling of heme iron in normal and pathological conditions; regulation by hepcidin]

Most of the iron required for erythropoiesis is provided by heme iron recycling following degradation of senescent erythrocytes by tissue macrophages. Accumulation of biochemical modifications at the red blood cell membrane during ageing (externalisation of phosphatidyl-serine, peroxydation of membrane-bound lipoproteins, loss of sialic acid residues and formation of senescence neoantigens) constitute a series of signals that will allow the macrophage to identify the red blood cells to be eliminated, through interaction with specific receptors. After this initial recognition step, the red blood cell is internalised by phagocytosis, and phagosome maturation, which can comprise recruitment of the endoplasmic reticulum, will favour degradation of red blood cell constituents. Heme is catabolised by heme oxygenase 1, anchored in the endoplasmic reticulum membrane. A fraction of the released iron will be recycled back to the plasma through ferroportin, a membrane-bound Fe (II) export molecule, and a fraction will retained within the ferritin molecules, to be released at later stages. Multiple evidence coming from human diseases (type 4 hemochromatosis) and animal models indicate that ferroportin is essential for heme iron recycling by macrophages. Furthermore, ferroportin seems to be the molecular target of hepcidin, this circulating peptide synthesized by the liver and acting as a negative regulator of intestinal iron absorption and iron recycling by macrophages. Perturbations in erythrophagocytosis play a physiopathological role in several diseases, including hemochromatosis, anemia of chronic disorders and thalassemia.

Increased erythropoiesis and subclinical inflammation as part of the metabolic syndrome

Recent studies have suggested the insulin resistance might be accompanied by enhanced erythropoiesis. We have examined this association in individuals with the metabolic syndrome (MS) who in addition to insulin resistance harbor a chronic low grade inflammation. This study is relevant because chronic inflammation might have a suppressive effect on erythropoiesis. 280 and 554 non-smoking women and men with respective age of 46.4+/-9.3 (mean+/-S.D.) and 44.0+/-11.0 years are included. A significant correlation was noted between the numbers of the components of the MS and the inflammatory biomarkers including the white blood cell count, high sensitivity C-reactive protein, fibrinogen concentrations and the erythrocyte sedimentation rate. In addition, a significant correlation (r=0.157, p=0.008) was noted between the number of components of the MS and the number of red blood cells in the peripheral blood in women. The same was true for men (r=0.192, p<0.0005). We conclude that enhanced erythropoiesis could be a new, hitherto unrecognized component of the MS. The enhanced erythropoiesis could give an erroneous impression of general "good" health in these individuals.

Primary iron overload with inappropriate hepcidin expression in V162del ferroportin disease

Ferroportin disease (hemochromatosis type 4) is a recently recognized disorder of human iron metabolism, characterized by iron deposition in macrophages, including Kupffer cells. Mutations in the gene encoding ferroportin 1, a cellular iron exporter, are responsible for this iron storage disease, inherited as an autosomal dominant trait. We present clinical, histopathological, and radiological findings in a family with the most common ferroportin mutation, V162del. In the index case, the disorder is characterized by abundant deposition of hemosiderin in all tissues investigated (mesenteric lymph node, liver, gastric and duodenal mucosa, and also in squamous cell carcinoma of the lung). The radiological findings indicated the presence of excess iron in bone marrow and spleen. Despite a significant burden of iron, no features of chronic liver disease were found in affected members of the family, including individuals aged up to 80 years. Hyperferritinemia greater than 1,000 microg/L was a penetrant biochemical finding before the second decade in life and was associated with significantly increased serum concentrations of pro-hepcidin that correlated positively with urinary hepcidin concentrations. In conclusion, the systemic iron burden in ferroportin disease is not a sufficient cause for chronic liver disease. In patients with most, but not all, ferroportin mutations, retention of iron in macrophages of the liver and other organs may protect against damage to parenchymal cells. Finally, macrophage iron storage in ferroportin disease is associated with elevated serum pro-hepcidin levels.

Anemia of inflammation: the hepcidin link

PURPOSE OF REVIEW

The anemia of inflammation has been associated for nearly two decades with elevated cytokine levels, but the primary mediator of this condition was unknown. Recently hepcidin antimicrobial peptide has emerged as the hormone that links the type II acute phase response to iron handling and erythropoiesis.

RECENT FINDINGS

Hepcidin antimicrobial peptide likely modulates iron transport from macrophages and enterocytes to red blood cell precursors as a consequence of its interaction with SLC40A1/ferroportin, the only known transporter that facilitates iron egress. Insights into the regulation of hepcidin antimicrobial peptide expression by known iron metabolic proteins such as HFE, hemojuvelin, and transferrin receptor 2 are expanding the understanding of the genetic circuitry that controls iron absorption and utilization.

SUMMARY

Increasingly, experiments suggest the hepatocyte is not just the iron storage depot but is the 'command central' for the maintenance of iron homeostasis. It receives multiple signals related to iron balance and responds via transcriptional control of hepcidin antimicrobial peptide.

Interferon gamma and tumour necrosis factor alpha in relation to anaemia and prognosis in childhood cancer

This study examined whether the initial plasma levels of tumour necrosis factor alpha (TNFalpha) and interferon gamma (IFNgamma) in 131 children with newly diagnosed cancer were associated with haematopoietic suppression, and whether plasma levels of TNFalpha or haemoglobin at diagnosis affects long-term prognosis in childhood acute lymphoblastic leukaemia (ALL).

CONCLUSIONS

IFNgamma, and possibly also TNFalpha, were related to anaemia in children with solid tumours. Neither TNFalpha levels nor Hb levels were associated with increased risk of ALL relapse.

Iron metabolism and toxicity

Iron is an essential nutrient with limited bioavailability. When present in excess, iron poses a threat to cells and tissues, and therefore iron homeostasis has to be tightly controlled. Iron's toxicity is largely based on its ability to catalyze the generation of radicals, which attack and damage cellular macromolecules and promote cell death and tissue injury. This is lucidly illustrated in diseases of iron overload, such as hereditary hemochromatosis or transfusional siderosis, where excessive iron accumulation results in tissue damage and organ failure. Pathological iron accumulation in the liver has also been linked to the development of hepatocellular cancer. Here we provide a background on the biology and toxicity of iron and the basic concepts of iron homeostasis at the cellular and systemic level. In addition, we provide an overview of the various disorders of iron overload, which are directly linked to iron's toxicity. Finally, we discuss the potential role of iron in malignant transformation and cancer.

Advances in understanding the molecular basis for the regulation of dietary iron absorption

PURPOSE OF REVIEW

The number of newly identified genes participating in the regulation of iron homeostasis has continued to expand at a remarkable pace. The roles for many have begun to be elucidated and there is an increasing indication that hepatocytes play a central role in determining the level of intestinal iron absorption. Total body iron homeostasis is dependent upon carefully regulated absorption of dietary iron, thus these genes are of fundamental importance in understanding of pathophysiology of such common disorders as hereditary hemochromatosis (HH) and the anaemia of chronic diseases.

RECENT FINDINGS

The hepatic peptide hepcidin plays a key role as a circulating hormone that regulates the absorption of dietary iron from the duodenum. Hepcidin expression is inappropriately decreased in hereditary hemochromatosis and is abnormally increased in the anaemia of chronic diseases. Other hepatic proteins essential for normal iron homeostasis, including HFE, transferrin receptor 2 (TfR2), and hemojuvelin, function at least in part, by modulating the expression of hepcidin.

SUMMARY

New insights into the pathophysiology of hereditary hemochromatosis and the anaemia of chronic diseases have been achieved with the recognition of the central role for hepcidin as an iron regulatory hormone. Investigations into the biologic control of this hormone and its mechanism of action offer the possibility of new therapeutic approaches to disorders of iron metabolism.

Correction of iron-deficient erythropoiesis in the treatment of anemia of chronic disease with recombinant human erythropoietin

Anemia of chronic disease (ACD) is a frequent complication of chronic inflammation in rheumatoid arthritis (RA). Recombinant human erythropoietin (rHuEpo) has been shown to be effective in correcting ACD, although with a variable rate of nonresponders. The first aim of this trial was to improve the response to rHuEpo by parenteral iron supplementation in cases of iron-deficient erythropoiesis (IDE). An additional goal was the evaluation of the zinc protoporphyrin content of erythrocytes (ZnPP), the soluble transferrin receptor (sTrfR) serum concentration, and the hemoglobin (Hb) content of reticulocytes (CHr) in stimulated erythropoiesis as diagnostic and prognostic parameters. Thirty RA patients with ACD were treated with subcutaneous 150 IU rHuEpo/kg body weight twice weekly. Intravenous iron supplementation (200 mg iron sucrose once weekly) was added in cases of IDE (n=23), which was defined by the presence of two of three criteria: saturation of transferrin (TrfS) < or =15%, hypochromic erythrocytes (HypoE) > or =10%, and a serum ferritin (Fn) concentration < or =50 microg/l. All 28 completers met the treatment goal, with an increase of the median Hb concentration from 10.3 g/dl to 13.3 g/dl. Epo treatment and iron supplementation was safe and well tolerated in all patients. Monitoring of Fn, TrfS, and HypoE every other week allowed a successful correction of anemia. Retrospective analysis of the evaluable parameters (CHr, sTrfR, and ZnPP) revealed no additional benefit for predicting or monitoring IDE in this setting, although the one or other may be advantageous in other therapeutic situations.

Calcitriol Increases Burst-Forming Unit-Erythroid Proliferation in Chronic Renal Failure

BACKGROUND

Calcitriol (C) improves anemia in chronic renal failure. This effect may be related to the suppression of iPTH release, or to a direct effect on erythropoiesis.

METHODS

Thirty-three patients with chronic renal failure were enrolled; among them, 24 were on chronic hemodialysis and 9 on conservative management. None had other chronic or hematological disease, aluminum levels were below 20 microg/l and DFO testing was negative. The iPTH range was 250-480 pg/l. None were treated with C or r-HuEpo. In vitro study: Samples were drawn for a basal erythroid precursor (burst forming unit-erythroid BFU-E) study: Mononuclear cells were incubated for 14 days with r-HuEpo 3U/ml (A), r-HuEpo 3U/l + C 30 pg (B), r-HuEpo 3U/ml + C 300 pg (C), or r-HuEpo 30 U/ml + C 300 pg (D). In vivo study: After the basal evaluation, 10 patients on chronic dialysis were treated with C (Calcijex-Abbott) 1 microg three times a week, and 4 patients served as controls. BFU-E studies were performed after 1, 2 and 4 months.

RESULTS

In vitro, culture B showed increased BFU-E proliferation vs. A (41 +/- 23 vs. 27 +/- 15, p < 0.02); in cultures C and D, proliferation was 61 +/- 31 and 78 +/- 42, respectively, p < 0.01 vs. A. There was no difference among patients with predialysis renal failure and those on dialysis. BFU-E proliferation was inversely related to basal Hb (p < 0.04) and CRP levels (p < 0.05). During the in vivo study, all cultures showed a progressive increase in proliferation without a plateau level (basal, after 1, 2 and 4 months, respectively) In A: 17 +/- 8, 22 +/- 13, 30.9 +/- 14.9, 41.4 +/- 20; in B: 27.3 +/- 15, 35.6 +/- 20, 45.5 +/- 21, 57 +/- 26; in C: 48.2 +/- 20.6, 63.7 +/- 32, 75.7 +/- 37, 83 +/- 40; in D: 72 +/- 24, 91 +/- 42, 106 +/- 42, 110 +/- 42.3 (all p < 0.001). Hb and Hct showed a significant increase (p < 0.03) in the treatment group. The decrease in iPTH was not related to BFU-E proliferation.

CONCLUSIONS

In chronic uremia, C has a direct effect on erythroid precursors proliferation, as demonstrated both in vitro and in vivo, with a synergistic effect with r-HuEpo. C may be a useful adjuvant therapy to r-HuEpo treatment.

Ferritin heavy chain upregulation by NF-kappaB inhibits TNFalpha-induced apoptosis by suppressing reactive oxygen species

During inflammation, NF-kappaB transcription factors antagonize apoptosis induced by tumor necrosis factor (TNF)alpha. This antiapoptotic activity of NF-kappaB involves suppressing the accumulation of reactive oxygen species (ROS) and controlling the activation of the c-Jun N-terminal kinase (JNK) cascade. However, the mechanism(s) by which NF-kappaB inhibits ROS accumulation is unclear. We identify ferritin heavy chain (FHC)--the primary iron storage factor--as an essential mediator of the antioxidant and protective activities of NF-kappaB. FHC is induced downstream of NF-kappaB and is required to prevent sustained JNK activation and, thereby, apoptosis triggered by TNFalpha. FHC-mediated inhibition of JNK signaling depends on suppressing ROS accumulation and is achieved through iron sequestration. These findings establish a basis for the NF-kappaB-mediated control of ROS induction and identify a mechanism by which NF-kappaB suppresses proapoptotic JNK signaling. Our results suggest modulation of FHC or, more broadly, of iron metabolism as a potential approach for anti-inflammatory therapy.

Indications et limites de l'utilisation d'érythropoïétine recombinée en réanimation

OBJECTIVE

To analyze the data from the literature on erythropoietin and the future indications of recombinant human erythropoietin in intensive care unit (ICU) patients.

DATA SOURCE

References were obtained from computerized bibliographic research (Pubmed) from 1986 to 2003, except for some physiologic data.

DATA SELECTION

Original articles, reviews, and letters to editor in French and English were selected and analyzed.

DATA SYNTHESIS

An anemia is often observed in patients hospitalized in ICU. This anemia may be due to many reasons. The management of anemia consists on the treatment of the underlying disease associated with the transfusion of red blood cells. Recent studies provided evidence of an association between transfusions and mortality in ICU patients. The anemia of ICU patients is compared to the anemia of chronic diseases, which is characterized by a blunted erythropoietin. A treatment with rHuEPO may be a future therapeutic of the anemia in such patients. A multicentric study shows the efficacy of recombinant erythropoietin therapy on a decrease in the use of red blood cell, and another clinical trial highlights a decrease of the proportion of ICU patients receiving red blood cell. Recombinant erythropoietin could be an alternative to transfusion in certain conditions and certain ICU patients. Further studies are needed to determine the consequences on mortality rate and to clarify the place of this therapy in ICU patients.

Anemia in chronic heart failure: pathogenetic mechanisms

Anemia can be the cause of heart failure, but also its consequence. The pathogenesis of anemia in chronic heart failure (CHF) has yet to be fully elucidated, but is likely to be complex. Epidemiologic studies suggest that kidney dysfunction (by reducing the erythropoietic response to anemia), inflammation (by inducing erythropoietin resistance), decreased body mass index, old age, female gender, and poor clinical status may be important factors in the development of anemia in CHF. Intestinal malabsorption, chronic aspirin use, and proteinuria predisposes to iron deficiency. Proinflammatory cytokines are likely to play a significant role in anemia in CHF by generating the "anemia of chronic illness" that is a hallmark of inflammatory conditions. Few studies have investigated the mechanisms of anemia in CHF. There is a need for such studies.