Heme-mediated cell activation: the inflammatory puzzle of sickle cell anemia

Malnutrition in sickle cell anemia: Prevalence, impact, and interventions: A Review

Sickle Cell Anemia (SCA) is a hereditary hemoglobinopathy characterized by chronic hemolytic anemia, vaso-occlusive events, and a wide range of clinical complications. Malnutrition, often an underexplored aspect of this complex condition, plays a critical role in disease management and overall patient well-being. This publication provides a comprehensive review of the prevalence, impact, and interventions related to malnutrition in individuals with SCA. A thorough literature review reveals the multifaceted challenges faced by SCA patients in maintaining adequate nutrition. The pathophysiology of SCA, involving chronic inflammation, oxidative stress, and hypermetabolism, contributes to increased nutritional requirements and altered dietary patterns. Factors such as reduced appetite, nutrient malabsorption, dietary restrictions, and socioeconomic disparities further exacerbate the risk of malnutrition. Malnutrition is a prevalent issue among individuals with SCA, affecting patients of different age groups and disease severities. Nutritional deficiencies, including vitamins, minerals, and essential nutrients, are common in this population. The impact of malnutrition on disease outcomes is significant, with associations between nutrient status and complications such as pain crises, infections, and impaired quality of life. This paper also reviews nutritional interventions aimed at addressing malnutrition in SCA patients. While dietary counseling, supplementation, and personalized nutrition plans have shown promise in improving nutritional status, challenges such as patient adherence and access to healthcare must be addressed to optimize their effectiveness.

Assessment of total and unbound cell-free heme in plasma of patients with sickle cell disease

Intravascular hemolysis results in the release of cell-free hemoglobin and heme in plasma. In sickle cell disease, the fragility of the sickle red blood cell leads to chronic hemolysis, which can contribute to oxidative damage and activation of inflammatory pathways. The scavenger proteins haptoglobin and hemopexin provide pathways to remove hemoglobin and heme, respectively, from the circulation. Heme also intercalates in membranes of blood cells and endothelial cells in the vasculature and associates with other plasma components such as albumin and lipoproteins. Hemopexin has a much higher affinity and can strip heme from the other pools and detoxify plasma from cell-free circulatory heme. However, due to chronic hemolysis, hemopexin is depleted in individuals with sickle cell disease. Thus, cell-free unbound heme is expected to accumulate in plasma. We developed a methodology for the accurate quantification of the fraction of heme, which is pathologically relevant in sickle cell disease, that does not appear to be sequestered to a plasma compartment. Our data show significant variation in the concentration of unbound heme, and rather unexpectedly, the size of the unbound fraction does not correlate to the degree of hemolysis, as measured by the concentration of bound heme. Very high heme concentrations (>150 µM) were obtained in some plasma with unbound concentrations that were several fold lower than in plasma with much lower hemolysis (<50 µM). These findings underscore the long-term effects of chronic hemolysis on the blood components and of the disruption of the essential equilibrium between release of hemoproteins/heme in the circulation and adaptative response of the scavenging/removal mechanisms. Understanding the clinical implications of this loss of response may provide insights into diagnostic and therapeutic targets in patients with sickle cell disease.

A Chemical Proteomic Map of Heme-Protein Interactions

Heme is an essential cofactor for many human proteins as well as the primary transporter of oxygen in blood. Recent studies have also established heme as a signaling molecule, imparting its effects through binding with protein partners rather than through reactivity of its metal center. However, the comprehensive annotation of such heme-binding proteins in the human proteome remains incomplete. Here, we describe a strategy which utilizes a heme-based photoaffinity probe integrated with quantitative proteomics to map heme-protein interactions across the proteome. In these studies, we identified 350+ unique heme-protein interactions, the vast majority of which were heretofore unknown and consist of targets from diverse functional classes, including transporters, receptors, enzymes, transcription factors, and chaperones. Among these proteins is the immune-related interleukin receptor-associated kinase 1 (IRAK1), where we provide preliminary evidence that heme agonizes its catalytic activity. Our findings should improve the current understanding of heme's regulation as well as its signaling functions and facilitate new insights of its roles in human disease.

Steamed Panax notoginseng and its Saponins Inhibit the Migration and Induce the Apoptosis of Neutrophils in a Zebrafish Tail-Fin Amputation Model

Panax notoginseng (PN) is a Chinese medicinal herb that is traditionally used to treat inflammation and immune-related diseases. Its major active constituents are saponins, the types and levels of which can be changed in the process of steaming. These differences in saponins are causally relevant to the differences in the therapeutic efficacies of raw and steamed PN. In this study, we have prepared the extracts of steamed PN (SPNE) with 70% ethanol and investigated their immunomodulatory effect using a zebrafish tail-fin amputation model. A fingerprint-effect relationship analysis was performed to uncover active constituents of SPNE samples related to the inhibitory effect on neutrophil number. The results showed that SPNE significantly inhibited the neutrophil number at the amputation site of zebrafish larvae. And SPNE extracts steamed at higher temperatures and for longer time periods showed a stronger inhibitory effect. Ginsenosides Rh1, Rk3, Rh4, 20(S)-Rg3, and 20(R)-Rg3, of which the levels were increased along with the duration of steaming, were found to be the major active constituents contributing to the neutrophil-inhibiting effect of SPNE. By additionally investigating the number of neutrophils in the entire tail of zebrafish larvae and performing TUNEL assays, we found that the decreased number of neutrophils at the amputation site was due to both the inhibition of their migration and apoptosis-inducing effects of the ginsenosides in SPNE on neutrophils. Among them, Rh1 and 20(R)-Rg3 did not affect the number of neutrophils at the entire tail, suggesting that they only inhibit the migration of neutrophils. In contrast, ginsenosides Rk3, Rh4, 20(S)-Rg3, and SPNE did not only inhibit the migration of neutrophils but also promoted neutrophilic cell death. In conclusion, this study sheds light on how SPNE, in particular the ginsenosides it contains, plays a role in immune modulation.

Chloroquine inhibits pro-inflammatory effects of heme on macrophages and invivo

BACKGROUND

Chloroquine has been used successfully to treat Malaria, including by chloroquine-resistant Plasmodium sp., indicating that it has effects on disease itself. Since heme has inflammatory effects and contributes to the pathogenesis of hemolytic diseases, we hypothesize that the anti-inflammatory effect of chloroquine is partially due to its inhibitory effect on heme-induced macrophage activation and on inflammatory tissue damage.

METHODS

Bone marrow derived macrophages (BMDMs) were incubated with chloroquine before stimulation with heme, in different conditions, to evaluate cytokines secretion, ROS production, mitogen activated protein kinases (MAPK) or spleen tyrosine kinase (Syk) activation, alone or combined with LPS. The effects of chloroquine upon heme inflammation were also evaluated in vivo, through simultaneous i.p. injection of LPS and heme, intratracheal instillation of Poly-IC followed by heme injection, and in a rhabdomyolysis model.

RESULTS

Chloroquine inhibited TNF secretion, mitochondrial ROS production, MAPK, and Syk activation induced by heme. Inhibition of TNF production could be mimicked by zinc ionophore quercetin, but not by primaquine, a chloroquine analog with low affinity for heme. IL-6 and IL-1β secretions induced by heme in the presence of PRRs agonists were inhibited by chloroquine, but not by calcium chelator BAPTA or inhibitor of endosomal acidification concamycin B. Chloroquine also protected mice from heme inflammatory effects in vivo, inhibiting lethal synergism with PRR agonists, lung pathology caused by heme injection after intratracheal instillation of Poly-IC, and delaying death after rhabdomyolisis.

CONCLUSION

Our data indicate that chloroquine might be used as a supportive therapy to control heme-induced deleterious inflammation in different hemolytic diseases.

Macrophage metabolic adaptation to heme detoxification involves CO-dependent activation of the pentose phosphate pathway

Heme is an essential cofactor for numerous cellular functions, but release of free heme during hemolysis results in oxidative tissue damage, vascular dysfunction, and inflammation. Macrophages play a key protective role in heme clearance; however, the mechanisms that regulate metabolic adaptations that are required for effective heme degradation remain unclear. Here we demonstrate that heme loading drives a unique bioenergetic switch in macrophages, which involves a metabolic shift from oxidative phosphorylation toward glucose consumption. Metabolomic and transcriptional analysis of heme-loaded macrophages revealed that glucose is funneled into the pentose phosphate pathway (PPP), which is indispensable for efficient heme detoxification and is required to maintain redox homeostasis. We demonstrate that the metabolic shift to the PPP is controlled by heme oxygenase-dependent generation of carbon monoxide (CO). Finally, we show that PPP upregulation occurs in vivo in organ systems central to heme clearance and that PPP activity correlates with heme levels in mouse sickle cell disease (SCD). Together, our findings demonstrate that metabolic adaptation to heme detoxification in macrophages requires a shift to the PPP that is induced by heme-derived CO, suggesting pharmacologic targeting of macrophage metabolism as a novel therapeutic strategy to improve heme clearance in patients with hemolytic disorders.

Associations between TGF-β1 Levels and Markers of Hemolysis, Inflammation, and Tissue Remodeling in Pediatric Sickle Cell Patients

Transforming growth factor beta (TGF-β) is a cytokine with important involvement in biological processes related to the pathogenesis of sickle cell disease (SCD), including endothelial and vascular dysfunction, inflammation, and hematopoietic homeostasis. This study is aimed at investigating associations between levels of TGF-β1 and classical laboratory biomarkers and inflammatory mediators, as well as the tissue inhibitor of metalloproteases-1 (TIMP-1) and matrix metalloproteinase-9 (MMP-9), in pediatric patients (n = 123) with SCD in steady state: 84 with sickle cell anemia (HbSS) and 39 with hemoglobin SC disease (HbSC). A healthy control (HC) group of 59 individuals was also included. Hematological and biochemical analyses were carried out using electronic methods. TGF-β1, TIMP-1, and MMP-9 plasma quantifications were performed by ELISA. TGF-β1 plasma levels were higher in HbSS individuals than in HbSC and HC. In individuals with HbSS, TGF-β1 levels were positively correlated with red blood cells, hemoglobin, hematocrit, platelets, and TIMP-1. In addition, HbSS individuals with TGF-β1 levels above the median (≥72.29 ng/mL) also presented increased monocyte counts and decreased albumin levels. In patients with HbSC, TGF-β1 levels were positively correlated with leukocytes, eosinophils, lymphocytes, monocytes, and platelets, as well as levels of TIMP-1, VLDL-C, triglycerides, heme, and AST. Additionally, HbSC individuals with TGF-β1 levels above the median (≥47.80 ng/mL) presented increased leukocyte and platelet counts, as well as increased levels of triglycerides, VLDL-C, MMP-9, and TIMP-1, and decreased HDL-C. Our findings suggest that TGF-β1 may play important roles in vascular remodeling, vasculopathy, angiogenesis, and inflammation in pediatric patients with SCD.

Effects of Red Blood Cell Sickling on Right Ventricular Afterload in vivo

BACKGROUND

Hemolysis in sickle cell disease (SCD) releases cell free hemoglobin, which scavenges nitric oxide (NO), leading to pulmonary vascular vasoconstriction, increased pulmonary vascular resistance (PVR), and the development of PH. However, PVR is only one component of right ventricular (RV) afterload. Whether sickled red blood cells increase the total RV afterload, including compliance and wave reflections, is unclear.

OBJECTIVE

Patients with SCD and pulmonary hypertension (PH) have a significantly increased risk of sudden death compared to patients with SCD alone. Sickled red blood cells (RBCs) are fragile and lyse easily. Here, we sought to determine the acute effects of SCD RBCs and increased cell free hemoglobin on RV afterload.

METHODS

Main pulmonary artery pressures and flows were measured in C57BL6 mice before and after exchanges of whole blood (~200 uL, Hct=45%) with an equal volume of SCD RBCs in plasma (Hct=45%) or cell free hemoglobin (Hb+) in solution. After transfusions, animals were additionally stressed with acute hypoxia (AH; 10% O2).

RESULTS

SCD RBCs increased PVR only compared to control RBCs; cell free hemoglobin increased PVR and wave reflections. These increases in RV afterload increased further with AH.

CONCLUSIONS

The release of cell free hemoglobin from fragile SCD RBCs in vivo increases the total RV afterload and may impair RV function more than the SCD RBCs themselves.

Transforming Growth Factor Beta Receptor 3 Haplotypes in Sickle Cell Disease Are Associated with Lipid Profile and Clinical Manifestations

Individuals with sickle cell disease (SCD) present both chronic and acute inflammatory events. The TGF-β pathway is known to play a role in immune response, angiogenesis, inflammation, hematopoiesis, vascular inflammation, and cell proliferation. Polymorphisms in the transforming growth factor-beta receptor 3 (TGFBR3) gene have been linked to several inflammatory diseases. This study investigated associations between two TGFBR3 haplotypes and classical laboratory parameters, as well as clinical manifestations, in SCD. We found that individuals with the GG haplotype presented higher levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), triglycerides, non-HDL cholesterol, total proteins, and globulin than individuals with non-GG haplotypes. In addition, the GG haplotype was associated with a previous history of pneumonia. Individuals with the CGG haplotype presented increased plateletcrit, TC, LDL-C levels, and non-HDL cholesterol. The CCG haplotype was also associated with a previous history of pneumonia. Our findings suggest that individuals with the GG and CGG haplotypes of TGFBR3 present important alterations in lipid profile.

TGFBR3 Polymorphisms (rs1805110 and rs7526590) Are Associated with Laboratory Biomarkers and Clinical Manifestations in Sickle Cell Anemia

Individuals with sickle cell anemia (SCA) present chronic anemia, hemolysis, an exacerbated inflammatory response, and heterogeneous clinical complications, which may be modulated by the transforming growth factor beta (TGF-β) pathway. Thus, we aimed to investigate polymorphisms (rs1805110 and rs7526590) of the transforming growth factor beta receptor III gene (TGFBR3) with regard to laboratory biomarkers and clinical manifestations in individuals with SCA. Hematological, biochemical, immunological, and genetic analyses were carried out, as well as serum endothelin-1 measurements. The minor allele (A) of the TGFBR3 rs1805110 polymorphism was associated with increased hemoglobin, hematocrit, reticulocyte counts, total cholesterol, low-density lipoprotein, uric acid, and endothelin levels, as well as decreased platelet distribution width (PDW) and the occurrence of bone alterations. The minor allele (T) of TGFBR3 rs7526590 was associated with increased red cell distribution width, PDW, alkaline phosphatase, aspartate aminotransferase, total and indirect bilirubin, and lactate dehydrogenase levels, as well as lower ferritin levels and the occurrence of leg ulcers. Our data suggest that the minor allele (A) of TGFBR3 rs1805110 is associated with inflammation and bone alterations, while the minor allele (T) of TGFBR3 rs7526590 is related to hemolysis and the occurrence of leg ulcers.

Heme is involved in the systemic inflammatory response following radiofrequency ablation of hepatic hemangiomas

OBJECTIVE

Radiofrequency ablation (RFA) is an effective and minimally invasive treatment for managing hepatic hemangiomas. Systemic inflammatory response syndrome (SIRS) often occurs with hemoglobinuria, and its underlying pathophysiological mechanism is unknown. Heme can trigger inflammation by inducing the generation of reactive oxygen species (ROS) and the production of inflammatory mediators. We therefore investigated whether circulating heme is involved in SIRS following RFA of hepatic hemangiomas.

METHODS

We enrolled 65 patients with hepatic hemangioma who underwent RFA. Serum concentrations of free heme, ROS, and tumor necrosis factor α (TNF-α) were measured after RFA. Univariate analysis and a multivariate binary logistic regression model were used to evaluate the contribution of 17 risk factors for SIRS after RFA.

RESULTS

Fifty-nine (59/65, 90.8%) patients developed hemoglobinuria, among which 25 (25/59, 42.4%) experienced SIRS shortly after RFA. In the SIRS group, the serum concentrations of heme, ROS, and TNF-α were immediately elevated after RFA compared with baseline and slowly regained their normal levels 3 days after RFA. Moreover, the concentrations of circulating heme significantly correlated with those of ROS (r = 0.805, P < 0.001) and TNF-α (r = 0.797, P < 0.001). Multivariate analysis showed that the volume of hemangioma [odds ratio (OR) = 1.293, P = 0.031], time of ablation (OR = 1.194, P = 0.029) as well as the concentrations of heme (OR = 1.430, P = 0.017), ROS (OR = 1.251, P = 0.031), and TNF-α (OR = 1.309, P = 0.032) were significantly associated with SIRS.

CONCLUSION

Circulating heme was associated with the induction of ROS and the production of TNF-α, which may contribute to the induction of SIRS following RFA of hepatic hemangiomas.

Investigation of Lipid Profile and Clinical Manifestations in SCA Children

Introduction

Clinical complications in sickle cell anemia (SCA) are heterogeneous and involve several molecules. It has been suggested that SCA individuals present a dyslipidemic phenotype and that lipid parameters are associated with severe clinical complications, such as pulmonary hypertension. We sought to investigate associations between lipid parameters and clinical manifestations, as well as other laboratory parameters in a population of pediatric SCA patients.

Methods

Our cross-sectional evaluation included 126 SCA patients in steady state and who were not undergoing lipid-lowering therapy. Hematological and biochemical parameters were characterized, and previous clinical manifestations were investigated.

Results

Total cholesterol and low-density lipoprotein cholesterol (LDL-C) levels were increased in patients with a previous history of pneumonia, which also positively correlated with HbS levels. Decreased LDL-C levels were also associated with leg ulcers and anemia. Elevated high-density lipoprotein cholesterol (HDL-C) levels were associated with pain crises, increased viscosity, and decreased hemolysis. Several studies have determined that lipids play a role in the vascular impairment seen in SCA, which was corroborated by our findings.

Conclusions

In sum, our results suggest that total cholesterol, HDL-C, and LDL-C levels are associated with hemolysis and anemia markers and, most importantly, with clinical complications related to vasculopathy in SCA.

Serum albumin is independently associated with higher mortality in adult sickle cell patients: Results of three independent cohorts

Sickle cell disease (SCD) impacts liver and kidney function as well as skin integrity. These complications, as well as the hyperinflammatory state of SCD, could affect serum albumin. Serum albumin has key roles in antioxidant, anti-inflammatory and antithrombotic pathways and maintains vascular integrity. In SCD, these pathways modulate disease severity and clinical outcomes. We used three independent SCD adult cohorts to assess clinical predictors of serum albumin as well its association with mortality. In 2553 SCD adult participants, the frequency of low (<35 g/L) serum albumin was 5%. Older age and lower hemoglobin (P <0.001) were associated with lower serum albumin in all three cohorts. In age and hemoglobin adjusted analysis, higher liver enzymes (P <0.05) were associated with lower serum albumin. In two of the three cohorts, lower kidney function as measured by Glomerular Filtration Rate (P<0.001) was associated with lower serum albumin. Lower serum albumin predicted higher risk of tricuspid regurgitation velocity ≥ 2.5 m/s (OR = 1.1 per g/L, P ≤0.01). In all three cohorts, patients with low serum albumin had higher mortality (adjusted HR ≥2.9, P ≤0.003). This study confirms the role of serum albumin as a biomarker of disease severity and prognosis in patients with SCD. Albumin as a biomarker and possible mediator of SCD severity should be studied further.

The cause and pathogenesis of hemolytic transfusion reactions in sickle-cell disease

PURPOSE OF REVIEW

The current review aims to summarize the epidemiology, cause, pathophysiology, and management of hemolytic transfusion reactions in sickle-cell disease (SCD).

RECENT FINDINGS

Patients undergoing occasional, isolated transfusions have been shown to have a higher risk of developing this condition. Despite the identification of well known risk factors, including alloimmunization, the pathophysiology of this syndrome remains unclear, as very severe forms with hyperhemolysis may develop in the absence of detectable antibodies, or with antibodies that are not considered to be clinically significant. Complement plays a crucial role in this reaction, particularly in cases of intravascular hemolysis. Complement triggers the reaction, but it also amplifies the inflammatory response and aggravates tissue damage. Free heme and hemoglobin are released and interact with complement, causing tissue damage.

SUMMARY

Hemolytic transfusion reactions are the most feared complications of blood transfusion in patients with SCD. This reaction is underdiagnosed because it mimics a vaso-occlusive crisis. Alloimmunization against red blood cell antigens is known to be a major trigger of this reaction, but abnormal complement activation and the underlying condition in patients with chronic hemolysis, may amplify the reaction. There is an urgent need to develop evidence-based approaches for preventing and treating this reaction.

Sickle cell disease: A distinction of two most frequent genotypes (HbSS and HbSC)

Sickle cell disease (SCD) consists of a group of hemoglobinopathies in which individuals present highly variable clinical manifestations. Sickle cell anemia (SCA) is the most severe form, while SC hemoglobinopathy (HbSC) is thought to be milder. Thus, we investigated the clinical manifestations and laboratory parameters by comparing each SCD genotype. We designed a cross-sectional study including 126 SCA individuals and 55 HbSC individuals in steady-state. Hematological, biochemical and inflammatory characterization was performed as well as investigation of previous history of clinical events. SCA patients exhibited most prominent anemia, hemolysis, leukocytosis and inflammation, whereas HbSC patients had increased lipid determinations. The main cause of hospitalization was pain crises on both genotypes. Vaso-occlusive events and pain crises were associated with hematological, inflammatory and anemia biomarkers on both groups. Cluster analysis reveals hematological, inflammatory, hemolytic, endothelial dysfunction and anemia biomarkers in HbSC disease as well as SCA. The results found herein corroborate with previous studies suggesting that SCA and HbSC, although may be similar from the genetic point of view, exhibit different clinical manifestations and laboratory alterations which are useful to monitor the clinical course of each genotype.

New insights into microvascular injury to inform enhanced diagnostics and therapeutics for severe malaria

Severe malaria (SM) has high mortality and morbidity rates despite treatment with potent antimalarials. Disease onset and outcome is dependent upon both parasite and host factors. Infected erythrocytes bind to host endothelium contributing to microvascular occlusion and dysregulated inflammatory and immune host responses, resulting in endothelial activation and microvascular damage. This review focuses on the mechanisms of host endothelial and microvascular injury. Only a small percentage of malaria infections (≤1%) progress to SM. Early recognition and treatment of SM can improve outcome, but we lack triage tools to identify SM early in the course of infection. Current point-of-care pathogen-based rapid diagnostic tests do not address this critical barrier. Immune and endothelial activation have been implicated in the pathobiology of SM. We hypothesize that measuring circulating mediators of these pathways at first clinical presentation will enable early triage and treatment of SM. Moreover, that host-based interventions that modulate these pathways will stabilize the microvasculature and improve clinical outcome over that of antimalarial therapy alone.

Hydroxyurea alters circulating monocyte subsets and dampens its inflammatory potential in sickle cell anemia patients

Sickle cell anemia (SCA) is a hemolytic disease in which vaso-occlusion is an important pathophysiological mechanism. The treatment is based on hydroxyurea (HU), which decreases leukocyte counts and increases fetal hemoglobin synthesis. Different cell types are thought to contribute to vaso-occlusion. Nevertheless, the role of monocytes subsets remains unclear. We investigated frequencies of monocytes subsets in blood and their response to HU therapy, testing their ability to express pro-inflammatory molecules and tissue factor (TF). We identified major changes in monocyte subsets, with classical monocytes (CD14⁺⁺CD16⁻) appearing highly frequent in who were not taking HU, whereas those with patrolling phenotype (CD14^dimCD16⁺) were enriched in individuals undergoing therapy. Additionally, HU decreased the production of TNF-α, IL1-β, IL-6, IL-8 as well as TF by the LPS-activated monocytes. Likewise, frequency of TF-expressing monocytes is increased in patients with previous vaso-occlusion. Moreover, activated monocytes expressing TF produced several pro-inflammatory cytokines simultaneously. Such polyfunctional capacity was dramatically dampened by HU therapy. The frequency of classical monocytes subset was positively correlated with percentage cytokine producing cells upon LPS stimulation. These findings suggest that classical monocytes are the subset responsible for multiple pro-inflammatory cytokine production and possibly drive inflammation and vaso-occlusion in SCA which is damped by HU.

Paraoxonases (PON) 1, 2, and 3 Polymorphisms and PON-1 Activities in Patients with Sickle Cell Disease

(1) Background: Oxidative stress, chronic inflammation, vasoocclusion, and free iron are all features present in sickle cell disease. Paraoxonases (PON) are a family (PON-1, PON-2, PON-3) of antioxidant enzymes with anti-inflammatory action. Here, for the first time, we described PON-1 activities and PON-1, PON-2, PON-3 polymorphisms in patients with sickle cell disease, homozygous for HbSS, compared with healthy controls. (2) Methods: The groups were matched for age and gender. PON-1 activities (arylesterase and paraoxonase) were determined by enzymatic hydrolysis of phenylcetate and paraoxon, respectively. Polymorphisms were determined by Restriction Fragment Length Polymorphism- Polymerase Chain Reaction (RFLP-PCR). (3) Results: Plasma cholesterol and fractions, ApoA1 and ApoB levels were all decreased in sickle cell disease patients, while anti-oxidized low-density lipoprotein (LDL) antibodies and C-reactive protein were increased. Serum arylesterase activity was lower in sickle cell disease patients when compared with healthy controls. In patients, paraoxonase activity was higher in those with PON-1 RR Q192R polymorphism. In these patients, the increase of serum iron and ferritin levels and transferrin saturation were less pronounced than those observed in patients with QQ or QR polymorphism. No differences were observed with PON-1 L55M, and PON-2 and PON-3 polymorphisms. Multivariate regression analysis showed that transferrin and ferritin concentrations correlated with arylesterase and paraoxonase activities. (4) Conclusions: Both transferrin and ferritin were the main predictors of decreased arylesterase and paraoxonase activities in patients with sickle cell disease. LDL oxidation increased, and RR PON-1 Q192R polymorphism is likely to be a protective factor against oxidative damage in these patients.

Alternate and Additional Functions of Erythrocyte Hemoglobin

The review discusses pleiotropic effects of erythrocytic hemoglobin (Hb) and their significance for human health. Hemoglobin is mostly known as an oxygen carrier, but its biochemical functions are not limited to this. The following aspects of Hb functioning are examined: (i) catalytic functions of the heme component (nitrite reductase, NO dioxygenase, monooxygenase, alkylhydroperoxidase) and of the apoprotein (esterase, lipoxygenase); (ii) participation in nitric oxide metabolism; (iii) formation of membrane-bound Hb and its role in the regulation of erythrocyte metabolism; (iv) physiological functions of Hb catabolic products (iron, CO, bilirubin, peptides). Special attention is given to Hb participation in signal transduction in erythrocytes. The relationships between various erythrocyte metabolic parameters, such as oxygen status, ATP formation, pH regulation, redox balance, and state of the cytoskeleton are discussed with regard to Hb. Hb polyfunctionality can be considered as a manifestation of the principle of biochemical economy.

The Use of Trace and Essential Elements in Common Clinical Disorders: Roles in Assessment of Health and Oxidative Stress Status

During the early life, the diet of infants is mainly dominated by milk. Milk is a natural food rich in trace elements focus on essential elements. These elements are very necessary for human metabolism and since they cannot be synthesized by the body, the only source available for the humans to obtain them is by ingestion of natural food. This mini-review aims at updating the knowledge on trace elements, outlining their natural food sources, and their possible implications in common clinical disorders in early and adult life. However, it was found that consumption of food with micronutrients and trace elements may release intracellular compounds and offer oxidative protection or exacerbate oxidative damage to metabolically compromised cells.

Microchimerism in Ghanaian children recipients of whole blood transfusion for severe anaemia

BACKGROUND AND OBJECTIVES

Transfusion-acquired microchimerism (TA-Mc) has been reported in major trauma but not in young children despite relative immunodeficiency who, in sub-Saharan Africa, often suffer severe anaemia related to haemoglobinopathies or primary malaria infections. We examined the hypothesis that such massive red cell destructions might provide conditions favourable to TA-Mc, particularly when exposed to massive amounts of parasite antigens.

MATERIALS AND METHODS

Twenty-seven female children <5 years transfused with male whole blood for severe anaemia (13 with acute malaria and 14 with other causes) were retrospectively identified, and a blood sample was collected >6 months post-transfusion. Four whole blood samples from paediatric females transfused with blood from female donors and five secondary school female students never pregnant, never transfused were used as negative controls.

RESULTS

Nineteen patients (70%) carried male Mc with four (15%) having high levels of Mc (>100 genome equivalent of male cells/million of host cells) compared to three controls (37·5%). There was no difference in frequency or quantity of male Mc between paediatric patients with severe malaria and paediatric patients with other causes of severe anaemia. TA-Mc was not correlated with patient age, duration of whole blood storage or lymphocyte load transfused. After a median of 7 months post-transfusion, acute malaria did not increase the frequency of TA-Mc. One negative control appeared to carry low-level male cells.

CONCLUSION

Transfusion-acquired microchimerism appears frequent in young children transfused with whole blood for severe anaemia.