Early Kidney Damage Markers after Deferasirox Treatment in Patients with Thalassemia Major: A Case-Control Study

The Importance and Essentiality of Natural and Synthetic Chelators in Medicine: Increased Prospects for the Effective Treatment of Iron Overload and Iron Deficiency

The supply and control of iron is essential for all cells and vital for many physiological processes. All functions and activities of iron are expressed in conjunction with iron-binding molecules. For example, natural chelators such as transferrin and chelator-iron complexes such as haem play major roles in iron metabolism and human physiology. Similarly, the mainstay treatments of the most common diseases of iron metabolism, namely iron deficiency anaemia and iron overload, involve many iron-chelator complexes and the iron-chelating drugs deferiprone (L1), deferoxamine (DF) and deferasirox. Endogenous chelators such as citric acid and glutathione and exogenous chelators such as ascorbic acid also play important roles in iron metabolism and iron homeostasis. Recent advances in the treatment of iron deficiency anaemia with effective iron complexes such as the ferric iron tri-maltol complex (feraccru or accrufer) and the effective treatment of transfusional iron overload using L1 and L1/DF combinations have decreased associated mortality and morbidity and also improved the quality of life of millions of patients. Many other chelating drugs such as ciclopirox, dexrazoxane and EDTA are used daily by millions of patients in other diseases. Similarly, many other drugs or their metabolites with iron-chelation capacity such as hydroxyurea, tetracyclines, anthracyclines and aspirin, as well as dietary molecules such as gallic acid, caffeic acid, quercetin, ellagic acid, maltol and many other phytochelators, are known to interact with iron and affect iron metabolism and related diseases. Different interactions are also observed in the presence of essential, xenobiotic, diagnostic and theranostic metal ions competing with iron. Clinical trials using L1 in Parkinson's, Alzheimer's and other neurodegenerative diseases, as well as HIV and other infections, cancer, diabetic nephropathy and anaemia of inflammation, highlight the importance of chelation therapy in many other clinical conditions. The proposed use of iron chelators for modulating ferroptosis signifies a new era in the design of new therapeutic chelation strategies in many other diseases. The introduction of artificial intelligence guidance for optimal chelation therapeutic outcomes in personalised medicine is expected to increase further the impact of chelation in medicine, as well as the survival and quality of life of millions of patients with iron metabolic disorders and also other diseases.

Dysregulated Iron Homeostasis as Common Disease Etiology and Promising Therapeutic Target

Iron is irreplaceably required for animal and human cells as it provides the activity center for a wide variety of essential enzymes needed for energy production, nucleic acid synthesis, carbon metabolism and cellular defense. However, iron is toxic when present in excess and its uptake and storage must, therefore, be tightly regulated to avoid damage. A growing body of evidence indicates that iron dysregulation leading to excess quantities of free reactive iron is responsible for a wide range of otherwise discrete diseases. Iron excess can promote proliferative diseases such as infections and cancer by supplying iron to pathogens or cancer cells. Toxicity from reactive iron plays roles in the pathogenesis of various metabolic, neurological and inflammatory diseases. Interestingly, a common underlying aspect of these conditions is availability of excess reactive iron. This underpinning aspect provides a potential new therapeutic avenue. Existing hematologically used iron chelators to take up excess iron have shown serious limitations for use but new purpose-designed chelators in development show promise for suppressing microbial pathogen and cancer cell growth, and also for relieving iron-induced toxicity in neurological and other diseases. Hepcidin and hepcidin agonists are also showing promise for relieving iron dysregulation. Harnessing iron-driven reactive oxygen species (ROS) generation with ferroptosis has shown promise for selective destruction of cancer cells. We review biological iron requirements, iron regulation and the nature of iron dysregulation in various diseases. Current results pertaining to potential new therapies are also reviewed.

Renal Dysfunction in Pediatric Patients in Iraq With β-Thalassemia Major and Intermedia

Background

With optimum transfusion and chelation therapy, the survival of β-thalassemia patients and the incidence of various complications, including renal complications, have improved.

Objectives

To investigate renal involvement in β-thalassemia patients using serum and urinary biochemical markers of glomerular and tubular dysfunction.

Methods

This case-control study included 69 β-thalassemia major (β-TM) patients, 23 β-thalassemia intermedia (β-TI) patients, and 100 healthy controls, all ranging from 1 to 16 years in age. Blood urea nitrogen (BUN), serum ferritin, serum and urinary levels of creatinine (Cr), uric acid (UA), calcium (Ca), phosphorus (Ph), magnesium (Mg), sodium (Na), and potassium (K), and the urinary albumin/creatinine ratio were evaluated.

Results

The BUN level and the urinary Na/Cr, K/Cr, Ca/Cr, Mg/Cr, Ph/Cr, albumin/Cr, and UA/Cr ratios were significantly higher in the β-thalassemia patients than in the controls. In contrast, the serum Na, K, Ca, and Mg levels were significantly lower in the patients (P<0.05). An elevated urinary UA/Cr ratio was found in 61.9% of β-thalassemia patients, and an elevated urinary Ca/Cr, and urinary albumin/Cr ratio was found in 53.2%. An elevated Na/Cr ratio was found in 41.3%. The serum and urinary renal markers showed no significant differences between patients with β-TM and β-TI, except for microscopic hematuria, which was significantly higher in β-TI patients (34.8%) than in β-TM patients (13%), P>0.02. At an older age, high serum ferritin levels and deferoxamine therapy were associated with significant tubular and glomerular dysfunction in β-thalassemia patients.

Conclusions

Pediatric patients with β-thalassemia have significantly abnormal tubular and glomerular functions, necessitating early detection and monitoring to prevent/reverse renal function deterioration.

Comparative evaluation of cystatin C and neutrophil gelatinase-associated lipocalin in patients with thalassemia major versus thalassemia intermedia

Kidney disorders are long-term complications in thalassemia patients, especially with the high life expectancy of these patients. Proper evaluation of kidney impairment in β-thalassemia patients can be difficult due to higher intake of iron chelators, resulting in renal impairment. Early biomarkers of renal disease are used for the diagnosis of tubular and glomerular abnormalities. The current study was conducted on 88 individuals, 25 healthy people and 63 β-thalassemia patients. Circulating levels of urea, creatinine, cystatin C and neutrophil gelatinase-associated lipocalin were measured in all groups. Compared to healthy control, patients with thalassemia major and intermedia showed a significant increase in both cystatin C and NGAL levels, with no effects on creatinine levels. Furthermore, urea levels were markedly higher in patients with thalassemia major compared to control. As early renal dysfunction markers, cystatin C and NGAL should be routinely evaluated in thalassemia patients major and intermedia.

Netrin-1 and clusterin: Innovative potential diagnostic biomarkers for early renal damage in β-thalassemia major children

BACKGROUND

Children with β-thalassemia major (β-TM) suffer from tubular dysfunction even before the onset of any renal impairment symptoms and/or clinical signs. Therefore, identifying innovative biomarkers allowing early renal damage detection has focused attention.

AIM

This study aims to preliminary assess Netrin-1(NTN-1) and clusterin (CLU) in β-TM children and explore their possible roles as surrogate noninvasive biomarkers of renal tubular dysfunction.

SUBJECTS AND METHODS

In this study, 40 β-TM children and 30 healthy children were enrolled. Routine serum and urinary biochemical variables were determined. Urinary NTN-1 and CLU levels were measured using ELISA and their mRNA expression in PBMCs were assayed using real-time PCR. Serum TNF-α, MDA levels and GST activity were measured.

RESULTS

Urinary NTN-1 and CLU concentrations and mRNA relative expression levels in PBMCs were significantly increased in β-TM children relative to controls. Oxidative stress and inflammatory markers revealed significant elevation in β-TM children compared to controls. The change in these parameters correlated significantly with other renal parameters. ROC curves analysis showed that urinary NTN-1 and CLU levels are of promising diagnostic performance.

CONCLUSION

Our results suggest that NTN-1 and CLU are qualified as new noninvasive biomarker panels for early detection of renal injury in β-TM children. Moreover, urinary NTN-1 is recommended as a precise one during the clinical practices.

Comparison of Treatment Effects of Different Iron Chelators in Experimental Models of Sepsis

Growing evidence indicates that dysregulated iron metabolism with altered and excess iron availability in some body compartments plays a significant role in the course of infection and sepsis in humans. Given that all bacterial pathogens require iron for growth, that iron withdrawal is a normal component of innate host defenses and that bacterial pathogens have acquired increasing levels of antibiotic resistance, targeting infection and sepsis through use of appropriate iron chelators has potential to provide new therapeutics. We have directly compared the effects of three Food and Drug Administration (FDA)-approved chelators (deferoxamine—DFO; deferiprone—DFP; and deferasirox—DFX), as were developed for treating hematological iron overload conditions, to DIBI, a novel purpose-designed, anti-infective and anti-inflammatory water-soluble hydroxypyridinone containing iron-selective copolymers. Two murine sepsis models, endotoxemia and polymicrobial abdominal sepsis, were utilized to help differentiate anti-inflammatory versus anti-infective activities of the chelators. Leukocyte adhesion, as measured by intravital microscopy, was observed in both models, with DIBI providing the most effective reduction and DFX the poorest. Inflammation in the abdominal sepsis model, assessed by cytokine measurements, indicated exacerbation by DFX and DFO for plasma Interleukin (IL)-6 and reductions to near-control levels for DIBI and DFP. Peritoneal infection burden was reduced 10-fold by DIBI while DFX and DFP provided no reductions. Overall, the results, together with those from other studies, revealed serious limitations for each of the three hematological chelators, i.e., as potentially repurposed for treating infection/sepsis. In contrast, DIBI provided therapeutic benefits, consistent with various in vitro and in vivo results from other studies, supporting the potential for its use in treating sepsis.

Iron-withdrawing anti-infectives for new host-directed therapies based on iron dependence, the Achilles' heel of antibiotic-resistant microbes

The iron dependence of antibiotic-resistant microbes represents an Achilles' heel that can be exploited broadly. The growing global problem of antibiotic resistance of microbial pathogens wherein microbes become resistant to the very antibiotics used against them during infection is linked not only to our health uses but also to agribusiness practices and the changing environment. Here we review mechanisms of microbial iron acquisition and host iron withdrawal defense, and the influence of iron withdrawal on the antimicrobial activity of antibiotics. Antibiotic-resistant microbes are unaltered in their iron requirements, but iron withdrawal from microbes enhances the activities of various antibiotics and importantly suppresses outgrowth of antibiotic-exposed resistant microbial survivors. Of the three therapeutic approaches available to exploit microbial iron susceptibility, including (1) use of gallium as a non-functional iron analogue, (2) Trojan horse conjugates of microbial siderophores carrying antibiotics, and (3) new generation iron chelators, purposely designed as anti-microbials, the latter offers various advantages. For instance, these novel anti-microbial chelators overcome the limitations of conventional clinically-used hematological chelators which display host toxicity and are not useful antimicrobials. 3-Hydroxypyridin-4-one-containing polymeric chelators appear to have the highest potential. DIBI (developmental code name) is a well-developed lead candidate, being a low molecular weight, water-soluble copolymer with enhanced iron binding characteristics, strong anti-microbial and anti-inflammatory activities, low toxicity for animals and demonstrated freedom from microbial resistance development. DIBI has been shown to enhance antibiotic efficacy for antibiotic-resistant microbes during infection, and it also prevents recovery growth and resistance development during microbe exposure to various antibiotics. Because DIBI bolsters innate iron withdrawal defenses of the infected host, it has potential to provide a host-directed anti-infective therapy.

Pyrroloquinoline quinone inhibits the production of inflammatory cytokines via the SIRT1/NF-κB signal pathway in weaned piglet jejunum

The small intestine is an important digestive organ and plays a vital role in the life of a pig. In this study, we explored the regulatory role and molecular mechanism of pyrroloquinoline quinone (PQQ) on intestinal health and to discussed the interaction between PQQ and vitamin C (VC). A total of 160 healthy piglets weaned at 21 d were randomly divided into four treatment groups according to 2 × 2 factoring. The results showed that dietary PQQ could significantly decrease the levels of plasma globulin, albumin/globulin (A/G), indirect bilirubin (IBIL), blood urea nitrogen (BUN), creatinine (CREA) (P < 0.05 for each), total bilirubin, (TBIL) (P < 0.01), diamine oxidase (DAO) (P < 0.01) and immunoglobulin G (IgG) (P < 0.0001) and increase the levels of immunoglobulin A (IgA) and immunoglobulin M (IgM) (P < 0.0001) in the plasma of weaned piglets. Similarly, dietary VC could significantly decrease the levels of plasma globulin, A/G, DAO (P < 0.05 for each) and IgG (P < 0.0001) and increase the levels of IgA and IgM (P < 0.0001) in the plasma of weaned piglets. In addition, dietary PQQ increased (P < 0.05) the mRNA levels of antioxidant genes (NQO1, UGT1A1, and EPHX1), thereby enhancing (oxidized) nicotinamide adenine dinucleotide (NAD+) concentration and sirtuin 1 (SIRT1) activity in tissues. However, the addition of 200 mg kg-1 VC to the diet containing PQQ reduced most of the effects of PQQ. We further show that PQQ reduced (P < 0.05) the expression of inflammation-related genes (IL-2, IL-6, TNF-α, and COX-2) via the SIRT1/NF-κB deacetylation signaling. In conclusion, our data reveals that PQQ exerts a certain protective effect on the intestines of piglets, but higher concentrations of VC react with PQQ, which inhibits the regulatory mechanism of PQQ.

Moxibustion with deferasirox results in safe, accelerated, and sustained cardiac iron chelation for a young Diamond Blackfan Anemia patient: An integrative case report

Diamond Blackfan Anemia (DBA) is a rare blood disorder of bone marrow failure typically identified in the first year of life. Due to treatment limitations, nearly all DBA patients are reliant upon chronic red cell infusion for some period of their lives. Repeat blood transfusion invariably leads to iron overload, which creates significant and life-threatening side effects. In this case report, a female child of 2 years and 8 months with DBA was diagnosed via T2* MRI imaging with potentially emergent levels of cardiac iron overload as a result of chronic red cell infusion. According to Chinese, Japanese, and integrative medicine principles, moxibustion was applied externally in conjunction with the prescribed oral chelation agent, deferasirox (DFX), over a period of six months. Analysis of repeat imaging at six months showed complete removal of cardiac iron and a one-third decrease in hepatic iron. In addition, there was no evidence of known risks to high-dose chelation, including renal, aural, or ocular damage. Follow-up examination two years after initial imaging showed no evidence of cardiac iron deposition with hepatic iron levels below minimum levels recommended for chelation despite the medical necessity of continued red cell infusion. This case study suggests that an integrative medical approach combining DFX with moxibustion may safely accelerate and sustain iron chelation for transfusion-dependent DBA patients. Recommendations for a successful approach to integrative iron chelation are provided in the case discussion.

Iron and Chelation in Biochemistry and Medicine: New Approaches to Controlling Iron Metabolism and Treating Related Diseases

Iron is essential for all living organisms. Many iron-containing proteins and metabolic pathways play a key role in almost all cellular and physiological functions. The diversity of the activity and function of iron and its associated pathologies is based on bond formation with adjacent ligands and the overall structure of the iron complex in proteins or with other biomolecules. The control of the metabolic pathways of iron absorption, utilization, recycling and excretion by iron-containing proteins ensures normal biologic and physiological activity. Abnormalities in iron-containing proteins, iron metabolic pathways and also other associated processes can lead to an array of diseases. These include iron deficiency, which affects more than a quarter of the world's population; hemoglobinopathies, which are the most common of the genetic disorders and idiopathic hemochromatosis. Iron is the most common catalyst of free radical production and oxidative stress which are implicated in tissue damage in most pathologic conditions, cancer initiation and progression, neurodegeneration and many other diseases. The interaction of iron and iron-containing proteins with dietary and xenobiotic molecules, including drugs, may affect iron metabolic and disease processes. Deferiprone, deferoxamine, deferasirox and other chelating drugs can offer therapeutic solutions for most diseases associated with iron metabolism including iron overload and deficiency, neurodegeneration and cancer, the detoxification of xenobiotic metals and most diseases associated with free radical pathology.