Effects of Iron Status on Adaptive Immunity and Vaccine Efficacy: A Review

Vaccines can prevent infectious diseases, but their efficacy varies, and factors impacting vaccine effectiveness remain unclear. Iron deficiency is the most common nutrient deficiency, affecting >2 billion individuals. It is particularly common in areas with high infectious disease burden and in groups that are routinely vaccinated, such as infants, pregnant women, and the elderly. Recent evidence suggests that iron deficiency and low serum iron (hypoferremia) not only cause anemia but also may impair adaptive immunity and vaccine efficacy. A report of human immunodeficiency caused by defective iron transport underscored the necessity of iron for adaptive immune responses and spurred research in this area. Sufficient iron is essential for optimal production of plasmablasts and IgG responses by human B-cells in vitro and in vivo. The increased metabolism of activated lymphocytes depends on the high-iron acquisition, and hypoferremia, especially when occurring during lymphocyte expansion, adversely affects multiple facets of adaptive immunity, and may lead to prolonged inhibition of T-cell memory. In mice, hypoferremia suppresses the adaptive immune response to influenza infection, resulting in more severe pulmonary disease. In African infants, anemia and/or iron deficiency at the time of vaccination predict decreased response to diphtheria, pertussis, and pneumococcal vaccines, and response to measles vaccine may be increased by iron supplementation. In this review, we examine the emerging evidence that iron deficiency may limit adaptive immunity and vaccine responses. We discuss the molecular mechanisms and evidence from animal and human studies, highlight important unknowns, and propose a framework of key research questions to better understand iron-vaccine interactions.

One-Bag 8-Step Ferric Carboxymaltose Desensitization Protocol for Patients with a History of Hypersensitivity Reactions to Iron Preparations

INTRODUCTION

Iron deficiency is the most common cause of anemia in both sexes, although it is more common in women. Intravenous (IV) iron replacement is preferred in patients who cannot tolerate oral treatment or when iron stores need to be replenished rapidly. In this study, we wanted to share the ferric carboxymaltose (FCM) desensitization protocol that we self-created and successfully applied.

METHODS

This retrospective cross-sectional study included patients with a history of hypersensitivity reactions (HSRs) to IV or oral iron replacement and patients who were planned to receive IV iron replacement but were referred to the allergy clinic because of have risk factors (atopic diseases, history of HSR to other drugs, high serum tryptase levels, etc.) for HSRs. Before desensitization, some of the patients underwent skin tests (skin prick test and intradermal test) with FCM, and the results were recorded. Skin tests were not performed in patients with a history of drug use (antihistamine, systemic steroid, omalizumab, etc.) that affected the results of skin tests. All patients underwent a one-bag 8-step desensitization protocol with 500 mg FCM and were observed for 2 h after desensitization.

RESULTS

A total of 15 patients (14 females and 1 male) with a mean age of 41.13 ± 11.18 years were included in the study. When the patients were evaluated in terms of the risk of allergic reactions according to their clinical history, 8 patients had a history of anaphylaxis with iron preparations (FCM, n = 4; ferric hydroxide sucrose, n = 2; iron [II] glycine sulfate, n = 1; and iron [III] hydroxide polymaltose, n = 1), and 7 patients had a history of HSR other than anaphylaxis with iron preparations (urticaria, n = 6 [FCM, n = 2; iron (II) glycine sulfate, n = 2; and iron (III) hydroxide polymaltose, n = 2] and urticaria + angioedema [ferric hydroxide sucrose, n = 1]). Desensitization was successfully completed in all patients. No HSR was observed during or after the procedure in any of the patients.

CONCLUSION

IV iron replacement is a very effective method, especially in cases where iron stores need to be replenished more rapidly. In patients with a history of iron HSR or at risk of developing HSR, replacement can be safely performed without an allergic reaction with successful desensitization protocols.

Neutrophil Inflammatory Response Is Downregulated by Uptake of Superparamagnetic Iron Oxide Nanoparticle Therapeutics

Superparamagnetic iron oxide nanoparticles (SPION) are employed as diagnostics and therapeutics following intravenous delivery for the treatment of iron deficiency anemia (IDA) in adult patients with chronic kidney failure. Neutrophils are the first defense against blood borne foreign insult and recruit to vascular sites of inflammation via a sequential process that is characterized by adhesive capture, rolling, and shear resistant arrest. A primary chemotactic agonist presented on the glycocalyx of inflamed endothelium is IL-8, which upon binding to its cognate membrane receptor (CXCR1/2) activates a suite of responses in neutrophils. An early response is degranulation with accompanying upregulation of β2-integrin (CD11/CD18) and shedding of L-selectin (CD62L) receptors, which exert differential effects on the efficiency of endothelial recruitment. Feraheme is an FDA approved SPION treatment for IDA, but its effect on the innate immune response of neutrophils during inflammation has not been reported. Here, we studied the immunomodulatory effects of Feraheme on neutrophils freshly isolated from healthy human subjects and stimulated in suspension or on inflammatory mimetic substrates with IL-8. Cells treated with Feraheme exhibited reduced sensitivity to stimulation with IL-8, indicated by reduced upregulation of membrane CD11b/CD18 receptors, high affinity (HA) CD18, and shedding of CD62L. Feraheme also inhibited N-formyl-Met-Leu-Phe (fMLP) induced reactive oxygen species production. Neutrophil rolling, arrest, and migration was assessed in vascular mimetic microfluidic channels coated with E-selectin and ICAM-1 to simulate inflamed endothelium. Neutrophils exposed to Feraheme rolled faster on E-selectin and arrested less frequently on ICAM-1, in a manner dependent upon SPION concentration. Subsequent neutrophil shape change, and migration were also significantly inhibited in the presence of Feraheme. Lastly, Feraheme accelerated clearance of cytosolic calcium flux following IL-8 stimulation. We conclude that uptake of Feraheme by neutrophils inhibits chemotactic activation and downregulates normal rolling to arrest under shear flow. The mechanism involves increased calcium clearance following chemotactic activation, which may diminish the efficiency of recruitment from the circulation at vascular sites of inflammation.

Comparison of Oral and Parenteral Iron Administration on Iron Homeostasis, Oxidative and Immune Status in Anemic Neonatal Pigs

The present study was to evaluate the consequences of iron status across oral and parenteral iron administrations in prevention of iron deficiency anemia. A total of 24 one-day-old male neonatal piglets were allocated into three groups given non-iron supplementation (NON), intramuscular iron dextran injection (FeDex), and oral administration of ferrous glycine chelate (FeGly), respectively. At day 8, no significant differences in final body weight, average weight gain, and tissue coefficients were observed among three groups (P > 0.05). Both oral FeGly and FeDex injection significantly increased serum iron, ferritin, hemoglobin, and tissue iron deposition (P < 0.05). However, FeDex-injected supplementation resulted in rapidly rising hepcidin levels and hepatic iron deposition (P < 0.05). In addition, compared to parenteral iron supplementation, greater serum IgA level, SOD, and GSH-Px activities, lower expressions of IL-1β and TNF-α in the liver, and lower expressions of IL-6 and TNF-α in the spleen were found in oral iron piglets (P < 0.05). According to our results, oral administration of ferrous glycine chelate improved iron homeostasis, and oxidative and immune status in anemic neonatal pigs.

Iron and prebiotic fortified flour improves the immune function of iron deficient women of childbearing age

Micronutrient deficiencies (MNDs) are common worldwide, in both developing as well as developed countries. MNDs such as Iron Deficiency not only compromise the nutritional status of individuals but can also put them at an increased risk of developing various other diseases by negatively affecting their immunity. The objective of the current research was to determine the effects of prebiotics and iron fortificants on various immunoglobulins among iron deficient women belonging to childbearing age. To serve the purpose, a total of seventy five iron deficient women were selected and randomly divided into one control and four treatment groups. Accordingly, different types of fortified wheat flour were prepared, based on varying dosage of prebiotics and iron fortificants, to be fed to anemic women on daily basis for three months. Two iron salts (FeSO₄ and NaFeEDTA) and two prebiotics (Galacto oligosaccharides and Inulin) were used to fortify wheat flour during the trials. Overnight fasted women were asked to give blood samples on monthly basis, up to three months. Four types of Immunoglobulins including IgA, IgE, IgG and IgM were determined at baseline, 30th, 60th and 90th day of trials using their respective protocols. The results of the study indicated that a statistically significant declining trend for IgA, IgE, IgG and IgM was present among the treatment groups (P-value < 0.05), compared to the control group. The study concluded that provision of iron and prebiotic fortified flour improved the immune function of iron deficient women.

Iron Promotes Intestinal Development in Neonatal Piglets

Early nutrition is key to promoting gut growth and education of the immune system. Although iron deficiency anemia has long been recognized as a serious iron disorder, the effects of iron supplementation on gut development are less clear. Therefore, using suckling piglets as the model for iron deficiency, we assessed the impacts of iron supplementation on hematological status, gut development, and immunity improvement. Piglets were parenterally supplied with iron dextran (FeDex, 60 mg Fe/kg) by intramuscular administration on the third day after birth and slaughtered at the age of two days, five days, 10 days, and 20 days. It was expected that iron supplementation with FeDex improved the iron status with higher levels of serum iron, ferritin, transferrin, and iron loading in the liver by regulating the interaction of hepcidin and ferroportin (FPN). FeDex supplementation increased villus length and crypt depth, attenuated the pathological status of the duodenum, and was beneficial to intestinal mucosa. FeDex also influenced the intestinal immune development by stimulating the cytokines’ production of the intestine and enhancing the phagocytotic capacity of monocytes. Overall, the present study suggested that iron supplementation helped promote the development of the intestine by improving its morphology, which maintains its mucosal integrity and enhances the expression of immuno-associated factors.

Assessment of peripheral blood lymphocyte subsets in children with iron deficiency anemia

BACKGROUND

Iron plays an important role in body defense and essential for normal immune system development where its deficiency may result in an inadequate immune response. We aimed to assess the lymphocyte subsets in childhood iron deficiency anemia (IDA) with their laboratory correlations.

METHODS

Fifty IDA (< 18 years) and 25 age and sex-matched healthy children were enrolled and a complete history was obtained and clinical examination was performed. Complete blood count, serum iron, total iron binding capacity and serum ferritin, were performed. Flow cytometric determination of peripheral blood CD3+, CD4+, CD8+ T-lymphocytes and CD19+ B-lymphocytes and CD4/CD8 ratio were done.

RESULTS

Patients had significantly lower hemoglobin, Serum iron, ferritin levels and higher lymphocytic count in patients compared with controls (p = 0.001, 0.03, 0.001, 0.001 respectively). CD3 count and percentage were significantly lower in IDA patients compared to controls (p = 0.007 and 0.005 respectively). There was a Significant reduction in the CD4 count, percentage and CD4/CD8 ratio in patients compared with controls (p = 0.001, 0.001 and 0.005 respectively) while there was no significant difference regarding CD8 count and percentage. No significant difference between the two studied groups regarding either CD19 count or percentage (p = 0.28 and 0.18 respectively) were found.

CONCLUSIONS

IDA is associated with impaired cell-mediated immune response specifically T-cell mediated immunity.

Impact of iron deficiency anemia on the function of the immune system in children

The importance of iron deficiency as a public health problem is based ultimately on the seriousness of its consequences on health. The most extensively investigated consequences of iron deficiency involve work performance and immune function. The significance of the effects on work performance is generally accepted. In contrast, data on the influence of iron deficiency on immune function are often perceived as being confusing and contradictory.We aimed to evaluate the effect of iron deficiency anemia on humoral, cellular, nonspecific immunity, and also the effect on the cytokines that are the key factors of many immunologic steps.Forty children with iron deficiency anemia and 20 age and sex-matched healthy children were included. All children were subjected to full medical history, thorough clinical examination, complete blood count, iron indices (serum iron, serum total iron-binding capacity, serum ferritin, and transferrin saturation), immunoglobulin assay (IgA, IgG, and IgM), interleukin (IL)-6 serum level, study of T-lymphocyte subsets, and evaluation of phagocytic function of macrophages and oxidative burst activity of neutrophils.Patients had significantly lower IgG levels, IL-6, phagocytic activity, and oxidative burst of neutrophils than controls, although there was no significant difference between patients and controls with regard to other immunoglobulins and CD4/CD8 ratio. There was significantly positive correlation between serum iron and IL-6 serum level.We concluded that humoral, nonspecific immunity (phagocytic activity and oxidative burst), and the IL-6 are influenced in patients with iron deficiency anemia. Study of these abnormalities after correction of iron deficiency is strongly needed.

Iron homeostasis: transport, metabolism, and regulation

PURPOSE OF REVIEW

Iron is essential for normal cellular function and many diseases result from disturbances in iron homeostasis. This review describes some of the recent key advances in iron transport and its regulation, how this relates to iron-related disorders, and emerging therapies for these diseases.

RECENT FINDINGS

The iron-regulatory hormone hepcidin and its target, the iron exporter ferroportin (FPN), play central roles in iron homeostasis. Recent studies have expanded our understanding of how hepcidin is regulated in response to stimulated erythropoiesis and have added some new players to the complex network of factors that influences hepcidin expression. Novel structural insights into how FPN transports iron have been an important addition to the field, as has the recognition that some zinc transporters such as ZIP14 can transport iron. Investigations into cardiac iron homeostasis have revealed a key role for FPN, and transferrin receptor 1, which is essential for cellular iron uptake, has been shown to be critical for normal immune function.

SUMMARY

The increased understanding of mechanisms of iron homeostasis that has resulted from recent research has greatly improved our ability to diagnose and manage iron-related disorders, and has offered new therapies for this important class of human diseases.

Overview of the Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia (BRINDA) Project

Anemia remains a widespread public health problem. Although iron deficiency is considered the leading cause of anemia globally, the cause of anemia varies considerably by country. To achieve global targets to reduce anemia, reliable estimates of the contribution of nutritional and non-nutritional causes of anemia are needed to guide interventions. Inflammation is known to affect many biomarkers used to assess micronutrient status and can thus lead to incorrect diagnosis of individuals and to overestimation or underestimation of the prevalence of deficiency in a population. Reliable assessment of iron status is particularly needed in settings with high infectious disease burden, given the call to screen for iron deficiency to mitigate potential adverse effects of iron supplementation. To address these information gaps, in 2012 the CDC, National Institute for Child Health and Human Development, and Global Alliance for Improved Nutrition formed a collaborative research group called Biomarkers Reflecting Inflammation and Nutrition Determinants of Anemia (BRINDA). Data from nationally and regionally representative nutrition surveys conducted in the past 10 y that included preschool children and/or women of childbearing age were pooled. Of 25 data sets considered for inclusion, 17 were included, representing ∼30,000 preschool children, 26,000 women of reproductive age, and 21,000 school-aged children from all 6 WHO geographic regions. This article provides an overview of the BRINDA project and describes key research questions and programmatic and research implications. Findings from this project will inform global guidelines on the assessment of anemia and micronutrient status and will guide the development of a research agenda for future longitudinal studies.

Leukocyte production of IFN-γ and TNF-α in 8- to 12-y-old children with low serum iron levels

OBJECTIVE

Iron deficiency is likely the most common nutritional deficiency worldwide; low iron concentrations have been related to alterations in immune system functions; therefore, the aim of this study was to determine the effect of low serum iron (LSI) concentrations on the production of proinflammatory cytokines by peripheral blood leukocytes in 8- to 12-y-old children from a local community.

METHODS

We obtained 120 blood samples and determined full blood counts and serum iron concentrations. An LSI and a control group, paired by age and sex were established using serum iron <60 μg/dL as the cutoff point. Ferritin and C-reactive protein concentrations were quantified. Serum interferon (IFN)-γ and tumor necrosis factor (TNF)-α concentrations were measured in these groups by enzyme-linked immunosorbent assay. A second blood sample was taken from children in both groups to isolate peripheral blood mononuclear cells (PBMCs) and measure IFN-γ and TNF-α production by unstimulated and lipopolysaccharide/phorbol myristate acetate/ionomycin-stimulated leukocytes in vitro.

RESULTS

Of the participants in the present study, 17.5% (21 children) presented LSI, as well as decreased ferritin concentrations. Differential counts from total blood samples showed a significant increase in leukocyte numbers in the LSI group, along with increased neutrophil frequencies and numbers but decreased lymphocyte frequencies. Decreased serum IFN-γ concentrations and decreased in vitro production of IFN-γ by PBMCs were found in the LSI group.

CONCLUSIONS

The results of the present study suggest that low iron levels alter leukocyte subpopulations in circulation and have a detrimental effect on leukocyte production of proinflammatory cytokines after an antigenic challenge.

Thyro-gastric autoimmunity in patients with differentiated thyroid cancer: a prospective study

Thyro-gastric autoimmunity has not been previously evaluated in patients with differentiated thyroid cancer (DTC), although its long-term complications may be relevant for the management of DTC patients. We assessed the prevalence of gastric autoimmunity and autoimmune gastritis (AG) in patients with Hashimoto's thyroiditis (HT) and concomitant DTC. Prevalence of parietal cell antibody (PCA) positivity, iron deficiency anemia (IDA), and pernicious anemia (PA) were prospectively assessed in 150 DTC patients referred for radioiodine ablation after total thyroidectomy. Patients were classified as HT (n = 31) and non-HT (n = 119) based on a combination of serological, ultrasonographic, and histological findings. Patients with PCA positivity were subsequently addressed to endoscopy for confirmation of atrophy body gastritis, required for the diagnosis of AG. For all the variables under study, a comparison between groups was made using Fisher's exact test and appropriate parametric and non-parametric tests. PCA positivity was significantly more prevalent in HT than in non-HT patients (12.9 vs 1.6 %, p = 0.017). After Hp eradication, a reversal of PCA positivity was observed in 3/4 patients in the HT group. IDA and PA did not differ significantly between groups. In the HT group, only one patient had endoscopical confirmation of mild gastric corporal atrophy. Gastric autoimmunity shows higher prevalence in patients with DTC and concomitant HT than in patients with DTC alone; however, in most cases, PCA positivity was associated with Hp infection. Furthermore, although previous reports found up to one-third of patients with HT to have associated AG, in our cohort AG was extremely rare.

[Clinical features and characteristics of community-acquired pneumonia associated with iron deficiency anemia in children of pre-school age]

The most common clinical signs of community-acquired pneumonia associated with iron deficiency anemia in children of pre-preschool age are defined. Indicators of immunity cellular link in children with community-acquired pneumonia are studied. It is established that acute illness is characterized by disturbances in cellular immunity that are more expressed in patients with concomitant iron deficiency anemia.

Immune deviation in recurrent vulvovaginal candidiasis: correlation with iron deficiency anemia

BACKGROUND

Iron Deficiency Anemia (IDA) has been controversially linked to IL-4 production in previous studies. A predominant Th1 response leads to resistance against recurrent vulvovaginal candidiasis (RVVC), whereas a Th2 response exacerbates the disease.

OBJECTIVE

To investigate the possible effect of iron deficiency on the host's susceptibility to RVVC as a result of the Th1/Th2 cytokine polarization.

METHODS

We conducted a case-control study of 92 women in 4 groups based on strict inclusion and exclusion criteria: RVVC+IDA+ group consisted of 23 women with RVVC and IDA; RVVC+ IDA- group consisted of 23 women with RVVC without IDA; RVVC-IDA+ group consisted of 23 women without RVVC and with IDA and RVVC- IDA- group consisted of 23 healthy women. The iron parameters and key cytokines (IFN-γ, IL-10, IL-12, IL-4) were measured in blood samples.

RESULTS

Comparison of IL-4 production between RVVC+ IDA+ (12.2 ± 1.3 pg/ml) and RVVC+ IDA- (2.4 ± 4.0 pg/ml) groups (p=0.044), between RVVC- IDA+ (14.6 ± 1.7 pg/ml) and RVVC- IDA- (1.28 ± 3.6 pg/ml) groups (p=0.006), between RVVC- IDA+ (14.6 ± 1.7 pg/ml) and RVVC+ IDA-) 2.4 ± 4.0 pg/ml) groups (p=0.009) and also between RVVC+ IDA+ and RVVC- IDA- (1.28 ± 3.6 pg/ml) groups (p=0.03) showed significant differences. We found a significant positive correlation between IL-4 and total iron binding capacity (TIBC, p=0.046) and between serum IL-10 and Hb levels (p=0.041) in the RVVC+ IDA- group. There was also a significant negative correlation between serum IL-4 and levels of serum iron (SI, p=0.041) in the RVVC- IDA- group.

CONCLUSION

It seems that IDA determines the balance between and the intensity of Th1 and Th2 arms of the immune response and leads to a deviation toward Th2 response which could contribute to recurrence of candidiasis.

Prevalence of gluten sensitive enteropathy antibodies in restless legs syndrome

The prevalence of restless legs syndrome (RLS) is increased in gluten sensitive enteropathy (GSE); but prevalence of GSE is not known in RLS. 96 RLS patients and 97 healthy controls, both with or without iron deficiency were enrolled. All secondary RLS patients except iron deficiency were excluded. Subjects underwent a thorough biochemistry and routine blood analyses, and tissue transglutaminase antibodies (TTGA), endomysium antibodies (EMA) and gliadin antibodies (AGA) were also tested. In RLS patients positivity rates of all GSE antibodies were similar to those in controls. The rate of iron deficiency anaemia in RLS patients with at least one positive GSE antibody was significantly higher than that of RLS patients whose GSE antibodies were all negative. The prevalence of GSE antibodies in RLS patients is not increased. GSE might have a role in the aetiology of RLS in association with iron deficiency anaemia. Since the prevalence of GSE antibodies is not increased in RLS, it seems unlikely that GSE is involved in the aetiology of RLS through different mechanisms (e.g. immunological mechanisms) other than iron deficiency as proposed in some published papers.

Low hepcidin accounts for the proinflammatory status associated with iron deficiency

Hepcidin is an antimicrobial peptide that controls systemic iron homeostasis. Hepcidin binding to its receptor ferroportin reduces iron availability, thus controlling microbial growth. In parallel it triggers an anti-inflammatory response in macrophages. Hepcidin is transcriptionally regulated by iron, through the bone morphogenetic protein-son of mothers against decapentaplegic (BMP-SMAD) pathway and by inflammation, through IL6-mediated STAT3 signaling. To investigate the mechanisms linking iron and inflammation, we treated C57BL/6 iron-deficient mice with a sublethal dose of lipopolysaccharide (LPS) and analyzed their inflammatory response in comparison with controls. We show that iron-deprived mice have a proinflammatory condition, exacerbated by LPS treatment leading to increased IL6 and TNFα mRNA in liver and spleen macrophages, and increased serum IL6 (482.29 ± 205.59 pg/mL) versus controls (69.01 ± 17.52 pg/mL; P < .05). Hepcidin was undetectable in iron-deficient mice but pretreatment with hepcidin normalized their response to LPS. Tmprss6(-/-) mice, characterized by iron deficiency and high hepcidin, show a blunted inflammatory response when challenged with LPS. Our data support a model in which the lack of hepcidin is responsible of the high inflammatory response to LPS in iron deficiency. The proinflammatory status associated with chronic iron deficiency could explain the resistance to infection seen in this condition.

Elevated systemic hepcidin and iron depletion in obese premenopausal females

Hepcidin, the body's main regulator of systemic iron homeostasis, is upregulated in response to inflammation and is thought to play a role in the manifestation of iron deficiency (ID) observed in obese populations. We determined systemic hepcidin levels and its association with body mass, inflammation, erythropoiesis, and iron status in premenopausal obese and nonobese women (n = 20/group) matched for hemoglobin (Hb). The obese participants also had liver and abdominal visceral and subcutaneous adipose tissue assessed for tissue iron accumulation and hepcidin mRNA expression. Despite similar Hb levels, the obese women had significantly higher serum hepcidin (88.02 vs. 9.70 ng/ml; P < 0.0001) and serum transferrin receptor (sTfR) (P = 0.001) compared to nonobese. In the obese women hepcidin was not correlated with serum iron (r = -0.02), transferrin saturation (Tsat) (r = 0.17) or sTfR (r = -0.12); in the nonobese it was significantly positively correlated with Tsat (r = 0.70) and serum iron (r = 0.58), and inversely with sTfR (r = -0.63). Detectable iron accumulation in the liver and abdominal adipose tissue of the obese women was minimal. Liver hepcidin mRNA expression was ~700 times greater than adipose tissue production and highly correlated with circulating hepcidin levels (r = 0.61). Serum hepcidin is elevated in obese women despite iron depletion, suggesting that it is responding to inflammation rather than iron status. The source of excess hepcidin appears to be the liver and not adipose tissue. The ID of obesity is predominantly a condition of a true body iron deficit rather than maldistribution of iron due to inflammation. However, these findings suggest inflammation may perpetuate this condition by hepcidin-mediated inhibition of dietary iron absorption.

Prevalence & consequences of anaemia in pregnancy

Prevalence of anaemia in India is among the highest in the world. Prevalence of anaemia is higher among pregnant women and preschool children. Even among higher income educated segments of population about 50 per cent of children, adolescent girls and pregnant women are anaemic. Inadequate dietary iron, folate intake due to low vegetable consumption, perhaps low B12 intake and poor bioavailability of dietary iron from the fibre, phytate rich Indian diets are the major factors responsible for high prevalence of anaemia. Increased requirement of iron during growth and pregnancy and chronic blood loss contribute to higher prevalence in specific groups. In India, anaemia is directly or indirectly responsible for 40 per cent of maternal deaths. There is 8 to 10-fold increase in MMR when the Hb falls below 5 g/dl. Early detection and effective management of anaemia in pregnancy can contribute substantially to reduction in maternal mortality. Maternal anaemia is associated with poor intrauterine growth and increased risk of preterm births and low birth weight rates. This in turn results in higher perinatal morbidity and mortality, and higher infant mortality rate. A doubling of low birth weight rate and 2 to 3 fold increase in the perinatal mortality rates is seen when the Hb is <8 g/dl. Intrauterine growth retardation and low birth weight inevitably lead to poor growth trajectory in infancy, childhood and adolescence and contribute to low adult height. Parental height and maternal weight are determinants of intrauterine growth and birth weight. Thus maternal anaemia contributes to intergenerational cycle of poor growth in the offspring. Early detection and effective management of anaemia in pregnancy can lead to substantial reduction in undernutrition in childhood, adolescence and improvement in adult height.

Early effects on T lymphocyte response to iron deficiency in mice. Short communication

Iron deficiency is a common nutritional disorder, affecting about 30% of the world population. Deficits in iron functional compartments have suppressive effects on the immune system. Environmental problems, age, and other nutrient deficiencies are some of the situations which make human studies difficult and warrant the use of animal models. This study aimed to investigate alterations in the immune system by inducing iron deficiency and promoting recuperation in a mouse model. Hemoglobin concentration, hematocrit, liver iron store, and flow cytometry analyses of cell-surface transferrin receptor (CD71) on peripheral blood and spleen CD4+ and CD8+ T lymphocyte were performed in the control (C) and the iron-deficient (ID) groups of animals at the beginning and end of the experiment. Hematological indices of C and ID mice were not different but the iron stores of ID mice were significantly reduced. Although T cell subsets were not altered, the percentage of T cells expressing CD71 was significantly increased by ID. The results suggest that iron deficiency induced by our experimental model would mimic the early events in the onset of anemia, where thymus atrophy is not enough to influence subset composition of T cells, which can still respond to iron deficiency by upregulating the expression of transferrin receptor.

Cold urticaria and celiac disease

Cold urticaria can be associated with blood and thyroid disorders, drugs, or infections. Celiac disease is an autoimmune enteropathy caused by permanent gluten intolerance. It is often associated with other autoimmune diseases, such as chronic idiopathic urticaria. Nevertheless, association with cold urticaria has not yet been described. A boy aged 3 years 8 months presented local urticaria-angioedema when exposed to cold temperatures. An ice cube test was positive and iron deficiency anemia was demonstrated. He later developed legume intolerance, rhinoconjunctivitis related to pollen sensitization, and asthma. Due to persistence of cold urticaria symptoms and refractory anemia, a test for immunoglobulin A autoantibodies to tissue transglutaminase and an intestinal biopsy were performed. Results of both tests were compatible with celiac disease.A study of human leukocyte antigen indicated a high risk phenotype (HLA, DR6/DR7; DQA 0501, 0201; DQB 0301, 0201). After 7 months of a gluten-free diet, the boy's anemia resolved and he is free of symptoms when exposed to cold. This is a first description of the possibility of an association between celiac disease and cold urticaria. A poor course of cold urticaria in the absence of evidence of another underlying condition should lead to suspicion of celiac disease.

Reticulocyte haemoglobin content vs. soluble transferrin receptor and ferritin index in iron deficiency anaemia accompanied with inflammation

Ferritin concentration, as a parameter of iron status that is commonly used in the diagnosis of iron deficiency anaemia (IDA), often has limited values if the iron deficiency is accompanied by inflammatory disease. This study evaluated the value of reticulocyte haemoglobin content (CHr) and soluble transferrin receptor-ferritin index (sTfR/F) in the diagnosis of IDA and differential diagnosis of IDA and anaemia of chronic disease. The study included 66 nonanaemic individuals as controls, 86 patients with IDA divided into noninflammatory and inflammatory subgroups, and 32 patients with anaemia of chronic disease. Blood count, iron, transferrin saturation, total iron binding capacity, ferritin, C-reactive protein, sTfR and CHr were determined. Receiver operator characteristic curve analysis showed very high discriminating power for CHr, soluble transferrin receptor (sTfR) and sTfR/F in the diagnosis of IDA. In patients with anaemia of chronic disease these parameters showed no significant difference from the control. CHr and sTfR enabled recognition of iron deficiency and were not affected by acute phase reaction. They are sensitive markers of body iron status with additional value to conventional tests for the detection of iron deficiency.

Nonhematological benefits of iron

Iron deficiency anemia is common in people with chronic kidney disease (CKD) and its importance in supporting erythropoiesis is unquestioned especially in those patients treated with erythropoietin. Clinical symptomatology such as fatigability, cold intolerance, failure to concentrate and poor effort intolerance is often attributed to anemia or uremia. That iron deficiency, per se, can cause these symptoms is poorly recognized. Clinical and animal studies that support the benefits of iron supplementation, independent of increasing hemoglobin, such as those on immune function, physical performance, thermoregulation, cognition, and restless leg syndrome and aluminum absorption is the subject of this narrative review.

Transferrin receptor in proliferation of T lymphocytes in infants with iron deficiency

The aim of this study was to contribute to clarify the mechanism of cellular immune insufficiency occurring during iron deficiency. We studied the expression of the transferrin receptor (TfR) which is called as CD71, on the surface of T lymphocytes in infants with iron deficiency (with and without anemia). A total of 33 infants, aged between 7 and 26 months were included in this study. These subjects were divided into three groups: (i) latent iron deficiency (LID) (group 1), (ii) iron deficiency anemia (IDA) (group 2), and (iii) healthy infants (group 3). Both CD3 levels and CD71 expression of T lymphocytes were analysed by flow cytometry before and after phytohaemagglutinin (PHA) stimulation. The percentage of CD3(+) lymphocytes in infants with IDA was lower than that in controls after PHA stimulation (mean +/- SD, 48.6 +/-10.5% vs. 70.7 +/-7.8%, P < 0.001). The TfR expression of T lymphocytes (CD3 + CD71%) increased in all three groups after PHA stimulation (P < 0.001). No significant difference was seen among the three groups with respect to CD3 + CD71%. Although there was a reduction in the proliferative capacity of T lymphocytes in infants with IDA, their ability to express transferrin receptor on T-lymphocyte cell surface was normal.