Renal complications in transfusion-dependent beta thalassaemia

Clinical Complications and Their Management

The diversity of disease-related complications among patients with β-thalassemia is complicated by the wide spectrum of genotypes and clinical risk factors. The authors herein present the different complications seen in patients with β-thalassemia, the pathophysiology underlying these complications and their management.

The Evaluation of Renal Iron Deposition With a 3 Tesla MRI Device in Beta-Thalassemia Major Patients

Background and objective Beta-thalassemia is the most frequent monogenic disease in the world. In beta-thalassemia major (BTM) patients, blood transfusions for severe anemia usually cause iron overload, leading to increased morbidity and mortality. In this study, we aimed to examine the iron overload in the kidneys of BTM patients with a 3 Tesla (3T) MRI device and assess the relationship between iron overload in the liver and heart as well as serum ferritin levels. Methods This was a retrospective study covering the period between November 2014 and March 2015. MRI was performed on 21 patients with BTM who were receiving blood transfusions and chelation therapy. The control group (n=11) included healthy volunteers. A 3T MRI device (Ingenia, Philips, Best, The Netherlands) using a 16-channel phased array SENSE-compatible torso coil was used. Three-point DIXON (mDIXON) sequence and the relaxometry method were employed to measure iron overload. Both kidneys were analyzed via mDIXON sequence for atrophy or variations. Afterward, the images in which renal parenchyma could be distinguished best were selected. Iron deposition was analyzed via the relaxometry method using a unique software (CMR Tools, London, UK). All data were analyzed using IBM SPSS Statistics v.21 (IBM Corp., Armonk, NY). The Kolmogorov-Smirnov test, independent samples t-test, Mann-Whitney U test, and Pearson's and Spearman's rho correlation coefficient were used. A p-value <0.05 was considered statistically significant. Results There was a statistically significant relationship between beta-thalassemia patients who had cardiac iron deposition and those who did not in terms of T2* time (p=0.02). In contrast, there was no similar relationship for liver iron deposition (p>0.05). Renal T2* values were significantly different between the patient and control groups (p=0.029). T2* times were significantly different between patients who had ferritin levels below 2500 ng/ml and those with ferritin levels above 2500 ng/ml (p=0.042). Conclusion Based on our findings, 3T MRI is a safe and reliable tool for screening iron overload in BTM patients as it makes distinguishing between renal parenchyma and renal sinus much easier and as it is more sensitive to iron deposition.

Clinical features and risk factors of renal dysfunctions in thalassemic patients

INTRODUCTION

Chronic anemia, iron overload, and iron chelation therapy are the main contributing factors for renal complications in thalassemia, e.g., nephrolithiasis, glomerular disease, and renal tubular dysfunction. The prevalence and associated factors for developing renal dysfunctions in Thai patients with thalassemia, however, remained limited. This study aimed to determine the prevalence and risk factors of renal dysfunctions in patients with thalassemia.

METHODS

A cross-sectional study was conducted on adult patients with thalassemia disease at Srinagarind Hospital, Khon Kaen University, Thailand. All patients were evaluated for complete blood count, blood chemistry, urinalysis, and urine biochemistry. Renal tubular dysfunction was defined as existing in at least one of the following parameters including; proteinuria, hypercalciuria, hypouricemia with uricosuria, or hypophosphatemia with phosphaturia. Logistic regression analysis was used to identify associated factors for renal dysfunctions.

RESULTS

Of 105 patients, renal tubular dysfunction was found in 60 patients (57.1%). In multivariate analysis of the clinical risk factors for renal tubular dysfunction in thalassemia patients, age per 10 year increase (adjusted odds ratio [AOR] = 1.4, 95% CI: 1.0-2.0, p value 0.01) and Hb E/beta-thalassemia (AOR = 3.6, 95% CI: 1.3-10.3, p value 0.01) were statistically proven to be associated with renal tubular dysfunction. Hyperuricosuria was a significantly associated factor for microhematuria. (AOR = 2.9, 95% CI: 1.1-8.0, p value 0.03).

CONCLUSIONS

Renal dysfunctions are prevalent in thalassemia patients, with older age and Hb E/beta-thalassemia genotype as significant risk factors for renal tubular dysfunction. Hyperuricosuria is a risk factor for microhematuria. Renal dysfunctions should be recognized and monitored in aging patients with Hb E/beta-thalassemia.

Endothelin-1 gene polymorphism (G8002A) and endothelial monocyte-activating polypeptide II: Role in vascular dysfunction in pediatric patients with β-thalassemia major

BACKGROUND

Endothelin-1 (ET-1), a potent endogenous vasoconstrictor, stimulates production of reactive oxygen species. Endothelial monocyte-activating polypeptide-II (EMAP-II) is a multifunctional polypeptide.

AIM

To assess ET-1 gene polymorphism (G8002A) in pediatric patients with β-thalassemia major (β-TM) as a potential genetic marker for vascular dysfunction and its possible relation to EMAP II, oxidative stress and vascular complications.

METHODS

β-TM patients (n = 95) without symptomatic cardiac or renal disease were compared with 95 healthy controls. Markers of hemolysis, serum ferritin, urinary albumin-to-creatinine ratio, serum EMAP II, malondialdehyde (MDA) and antioxidant enzymes; superoxide dismutase (SOD), glutathione peroxidase (GPx), reduced glutathione (GSH), glutathione reductase and catalase were measured. ET-1 gene polymorphism (G8002A) was determined using polymerase chain reaction‑restriction fragment length polymorphism.

RESULTS

β-TM patients had significantly higher EMAP II than healthy controls. EMAP II was significantly higher among patients with cardiac disease, pulmonary hypertension (PH) risk, nephropathy, poor compliance to therapy and ferritin ≥ 2500 μg/L. There were significant correlations between EMAP II and transfusion index, LDH, ferritin and oxidative stress markers. The AA genotype of ET-1 gene polymorphism (G8002A) was significantly higher among β-TM patients than controls. The number of patients with cardiac disease, PH risk or nephropathy was significantly higher among AA genotype compared with GG and GA genotypes. Lactate dehydrogenase (LDH), serum ferritin, EMAP II, MDA, SOD and GPx were significantly higher in AA genotype.

CONCLUSION

ET-1 gene polymorphism (G8002A) could be a possible genetic marker for prediction of increased susceptibility to cardiopulmonary and renal complications among pediatric patients with β-TM.

The Assessment of Renal Functional Reserve in β-Thalassemia Major Patients by an Innovative Ultrasound and Doppler Technique: A Pilot Study

Beta-thalassemia syndromes are the most common inherited monogenic disorders worldwide. The most common pathophysiologic and clinical renal disease manifestations of in β-TM patients is the tubular dysfunctions related to iron overload, chronic anemia, and the need for chronic iron chelation therapy. The aim of this pilot study is to apply an innovative ultrasound and Doppler technique to assess the Renal Functional Reserve (RFR) in β-TM patients, and to evaluate its reliability in iron overload tubulopathy. Ultrasound assessment of intra-parenchymal renal resistive index variation (IRRIV) has recently been proposed as a safe and reproducible technique to identify RFR presence. We define the preserved RFR when the Delta Renal Resistive Index (RRI) is >0.05 (baseline RRI—minimum RRI value during stress) in the Renal Stress Test (RST). Nineteen β-TM patients were enrolled for this study. In our series, we found a strong negative correlation between mean ferritin values and Delta RRI (R = −0.51, p = 0.03). This pilot study suggested the RST as reliable tool for assessing the RFR by ultrasound. Specifically, RST could help in clinical practice suggesting the patient’s management and iron chelation therapy.

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.

Beta-thalassaemia major: Prevalence, risk factors and clinical consequences of hypercalciuria

Regular transfusion and chelation therapy produces increased life expectancy in thalassaemic patients who may develop new complications. Since few data are available regarding hypercalciuria in β‐thalassaemia major (TM), the aim of our study was to evaluate its prevalence, risk factors and clinical consequences. We enrolled 176 adult TM patients followed at the Center of Thalassemia of Ferrara. Hypercalciuria was defined by a calciuria of 4 mg/kg/day or more in a 24‐h urine sample. Anamnestic, biochemical and radiological data were collected. Hypercalciuria prevalence was reported in 69.3% of patients (females 52.5%). Hypercalciuric (HC) patients used deferasirox (DFX) more often than normocalciuric (NC) patients (47.5% vs 29.6%; p < 0.05). In HC subjects plasma parathyroid hormone (PTH) (24.1 ± 10.4 vs 30.1 ± 13.2 pg/ml) and phosphate levels (3.6 ± 0.5 vs 3.8 ± 0.7 mg/dl) were lower, whereas serum calcium (9.6 ± 0.4 vs 9.4 ± 0.4 mg/dl) and urinary 24‐h phosphaturia (0.9 ± 0.4 vs 0.6 ± 0.3 g/day) were higher as compared to NC patients (p < 0.05 for all comparisons). Supplementation with oral calcium and cholecalciferol was similar between the groups. A higher rate of kidney stones was present in HC (14.8%) versus NC patients (3.7%) (p < 0.05). Hypercalciuria is a frequent complication in adequately treated adult TM patients. Hypercalciuria prevalence is increased in DFX users whereas haemoglobin level or calcium supplements play no role. A significant proportion of HC patients developed kidney stones.

Setting for "Normal" Serum Ferritin Levels in Patients with Transfusion-Dependent Thalassemia: Our Current Strategy

This cross-sectional study aimed to establish the association between serum ferritin levels and organ iron overload (IO) and overall morbidity in transfusion-dependent thalassemia (TDT) patients. One hundred and three TDT patients (40.03 ± 9.15 years; 57.3% females) with serum ferritin < 2500 ng/mL were included. IO was assessed by T2* magnetic resonance imaging. Three groups were identified based on mean serum ferritin levels: <500 ng/mL (group 0; N = 32), 500-1000 ng/mL (group 1; N = 43), and 1000-2500 ng/mL (group 2; N = 28). All demographic and biochemical parameters were comparable among the three groups, with the exception of the triglycerides being significantly lower in group 0 than in group 2. No difference was found in the frequency of hepatic, endocrine, and cardiac complications. Hepatic IO was significantly less frequent in group 0 versus both groups 1 and 2. No patient with a serum ferritin level < 500 ng/mL had significant myocardial IO and alterations in the main hematological parameters. No difference in the distribution of the different chelation regimens was found. Serum ferritin < 500 ng/mL appears to be achievable and safe for several TDT patients. This target is associated with the absence of significant cardiac iron and significantly lower hepatic IO and triglycerides that are well-demonstrated markers for cardiac and liver complications.

Renal function in β-thalassemia major patients treated with two different iron-chelation regimes

BACKGROUND

Renal injury in transfusion dependent β thalassemia patients (TDT) has been attributed to iron overload, chronic anemia and iron-chelation therapy (ICT) toxicity. We studied renal function in TDT patients treated with two different ICT regimes.

PATIENTS AND METHODS

We studied 36 TDT patients: 26 received deferasirox (DFX) and 10 were treated with deferoxamine (DFO) +/- deferiprone (DFP).

RESULTS

Increased uNAG was found in 30% of the DFX group vs. 10% of the DFO+/-DFP group, the mean uNAG level in the DFX group was significantly higher than in the DFO+/-DFP group, (P < 0.05). A moderate negative correlation was found between uNAG levels and mean serum ferritin for the prior 10 years (P = 0.03), more pronounced for the DFO+/-DFP group. Twenty nine patients had had their renal function evaluated 10 years earlier; eGFR significantly declined in patients switched to DFX (P = 0.0093) but not in patients who continued DFO+/-DFP.

CONCLUSIONS

A high prevalence of renal tubular damage was observed in our TDT patients, particularly those treated with DFX; uNAG was negatively associated with mean 10-year serum ferritin, suggesting ICT's involvement in tubular injury. A significant decline in eGFR compared to a decade earlier was observed only in patients currently treated with DFX. Strict follow-up of renal function in TDT patients is warranted.

β-Thalassemia minor & renal tubular dysfunction: is there any association?

Objective

Beta(β)-thalassemia is one of the most common hereditary hematologic disorders. Patients with thalassemia minor (TM) are often asymptomatic and the rate of renal dysfunction is unknown in these patients. Due to the high prevalence of renal dysfunction in Iran, the current study aimed to determine renal tubular dysfunction in patients with beta-TM.

Methods

In this case-control study, 40 patients with TM and 20 healthy subjects were enrolled and urinary and blood biochemical analysis was done on their samples. Renal tubular function indices were determined and compared in both groups. Data was analyzed by SPSS software, version 20.0.

Results

The fraction excretion (FE) of uric acid was 8.31 ± 3.98% in the case and 6.2 ± 34.71% in the control group (p = 0.048). Also, FE of potassium was significantly higher in patients with TM (3.22 ± 3.13 vs. 1.91 ± 0.81; p = 0.036). The mean Plasma NGAL level was 133.78 ± 120.28 ng/mL in patients with thalassemia and 84.55 ± 45.50 ng/mL in the control group (p = 0.083). At least one parameter of tubular dysfunction was found in 45% of patients with thalassemia.

Conclusion

Based on the results of this study, the prevalence of tubular dysfunction in beta-thalassemia minor patients is high. Due to the lack of knowledge of patients about this disorder, periodic evaluation of renal function in TM patients can prevent renal failure by early diagnosis.

From Biology to Clinical Practice: Iron Chelation Therapy With Deferasirox

Iron chelation therapy (ICT) has become a mainstay in heavily transfused hematological patients, with the aim to reduce iron overload (IOL) and prevent organ damage. This therapeutic approach is already widely used in thalassemic patients and in low-risk Myelodysplastic Syndrome (MDS) patients. More recently, ICT has been proposed for high-risk MDS, especially when an allogeneic bone marrow transplantation has been planned. Furthermore, other hematological and hereditary disorders, characterized by considerable transfusion support to manage anemia, could benefit from this therapy. Meanwhile, data accumulated on how iron toxicity could exacerbate anemia and other clinical comorbidities due to oxidative stress radical oxygen species (ROS) mediated by free iron species. Taking all into consideration, together with the availability of approved oral iron chelators, we envision a larger use of ICT in the near future. The aim of this review is to better identify those non-thalassemic patients who can benefit from ICT and give practical tips for management of this therapeutic strategy.

Comparing different markers of tubular dysfunction in transfusion-dependent thalassemia patients

BACKGROUND

Renal tubular dysfunction was reported in transfusion-dependent thalassemia (TDT) patients and ranges from mild to severe. The objectives of our study were identification of the best marker of early renal tubular dysfunction in TDT patients among the three most commonly used urinary biomarkers, named neutrophil gelatinase-associated lipocalin (NGAL), retinol-binding protein (RBP) and N-acetyl-D-glucosaminidase (NAG) and correlation of these biomarkers with different patient variables.

METHODOLOGY

Sixty-one TDT patients and another 62 healthy children were enrolled in a cross-sectional study. Morning urine samples were taken for measurement of calcium, phosphorus, creatinine, microalbumin and markers of tubular dysfunction (NGAL, NAG and RBP). Urine NGAL/creatinine (UrNGAL/Cr), urine NAG/creatinine (UrNAG/Cr) and urine RBP/creatinine (UrRBP/Cr) ratios were used for accuracy. Patients were classified into 2 groups: group A, with tubular dysfunction and group b, without tubular dysfunction.

RESULTS

Group A showed statistically significant higher UrNGAL/Cr (p < 0.001), UrRBP/Cr (p < 0.001) and UrNAG/Cr (p <0.001) than group B. In group A, microalbuminuria was detected only in 7 patients (28%) while it was detected in 12 patients (33.3%) in group B. By using ROC curve analysis, the diagnostic cutoff values for UrNGAL/Cr, UrRBP/Cr and UrNAG/Cr were 3713.38, 1614.85 and 56.56 ng/g, respectively. We found a statistically significant superiority of UrNGAL/Cr over UrRBP/Cr (p < 0.001) and UrRBP/Cr over UrNAG/Cr (p < 0.001).

CONCLUSION

Evaluation of UrNGAL/Cr, UrRBP/Cr and UrNAG/Cr could early discriminate tubular dysfunction TDT patients from those with normal tubular function. UrNGAL/Cr is more accurate in early detection of tubular dysfunction when compared with the other two biomarkers.

Assessment of Subclinical Renal Glomerular and Tubular Dysfunction in Children with Beta Thalassemia Major

Background: A good survival rate among patients with beta thalassemia major (beta-TM) has led to the appearance of an unrecognized renal disease. Therefore, we aimed to assess the role of serum cystatin-C as a promising marker for the detection of renal glomerular dysfunction and N-acetyl beta-D-glucosaminidase (NAG) and kidney injury molecule 1 (KIM-1) as potential markers for the detection of renal tubular injury in beta-TM children. Methods: This case-control study was implemented on 100 beta-TM children receiving regular blood transfusions and undergoing iron chelation therapy and 100 healthy children as a control group. Detailed histories of complete physical and clinical examinations were recorded. All subjected children underwent blood and urinary investigations. Results: There was a significant increase in serum cystatin-C (p < 0.001) and a significant decrease in eGFR in patients with beta-TM compared with controls (p = 0.01). There was a significant increase in urinary NAG, KIM-1, UNAG/Cr, and UKIM-1/Cr (p < 0.001) among thalassemic children, with a significant positive correlation between serum cystatin-C, NAG and KIM-1 as regards serum ferritin, creatinine, and urea among thalassemic patients. A negative correlation between serum cystatin-C and urinary markers with eGFR was noted. Conclusion: Serum cystatin-C is a good marker for detection of glomerular dysfunction. NAG and KIM-1 may have a predictive role in the detection of kidney injury in beta-TM children.

Occult Kidney Dysfunction in Children With Transfusion-Dependent Thalassemia

Background: Thalassemia is the commonest hemoglobinopathy in Southeast Asia. Kidney dysfunction is an underreported sequelae in children with thalassemia. We conducted a retrospective study to identify the prevalence of and predisposing factors for kidney dysfunction in children with transfusion-dependent thalassemia (TDT). Method: Abnormal kidney function was defined as children with a glomerular filtration rate (GFR) of <90 ml/min/1.73 m² or a decline in GFR of >20 ml/min/1.73 m² or presence of nephrotic range proteinuria within 3 years of commencing regular (every ≤6 weeks) red cell transfusion. Data analyzed were age at diagnosis of thalassemia, number of transfusion-years, iron chelation therapy, serum ferritin, and pre-transfusion hemoglobin levels. Results: Eighty-one children were studied. Mean age was 11.72 ± 5.275 years. Thirty out of 81 (37%) demonstrated abnormal kidney function. Evidence of glomerular hyperfiltration was seen in 29/81 patients (25.85%) at their last clinic visit. This fraction was doubled [48/81 (59.3%)] when the cohort was tracked back by 3 years from the last clinic encounter. Age at diagnosis (RR, 1.157; 95% CI, 1.014-1.319; p = 0.03) and duration of receiving transfusions (RR, 0.984; 95% CI, 0.974-0.994; p = 0.001) were associated with increased risk of developing abnormal kidney function. Conclusion: Abnormal kidney function in children with TDT may be overlooked by medical personnel without active screening measures. Children receiving regular red cell transfusions require systematic surveillance to enable early detection of kidney dysfunction and timely implementation of appropriate therapeutic interventions.

Cardiorenal syndrome in thalassemia patients

Background

Cardiorenal syndrome (CRS), a serious condition with high morbidity and mortality, is characterized by the coexistence of cardiac abnormality and renal dysfunction. There is limited information about CRS in association thalassemia. This study aimed to investigate the prevalence of CRS in thalassemia patients and also associated risk factors.

Methods

Thalassemia patients who attended the out-patient clinic of a tertiary care university hospital from October 2016 to September 2017 were enrolled onto this cross-sectional study. Clinical and laboratory findings from 2 consecutive visits, 3 months apart, were assessed. The criteria for diagnosis of CRS was based on a system proposed by Ronco and McCullough. Cardiac abnormalities are assessed by clinical presentation, establishment of acute or chronic heart failure using definitions from 2016 ESC guidelines or from structural abnormalities shown in an echocardiogram. Renal dysfunction was defined as chronic kidney disease according to the 2012 KDIGO guidelines.

Results

Out of 90 thalassemia patients, 25 (27.8%) had CRS. The multivariable analysis showed a significant association between CRS and extramedullary hematopoiesis (EMH) (odds ratio (OR) 20.55, p = 0.016); thalassemia type [β⁰/β^E vs β⁰/β⁰ thalassemia (OR 0.005, p = 0.002)]; pulmonary hypertension (OR 178.1, p = 0.001); elevated serum NT-proBNP (OR 1.028, p = 0.022), and elevated 24-h urine magnesium (OR 1.913, p = 0.016). There was no association found between CRS and frequency of blood transfusion, serum ferritin, liver iron concentration, cardiac T2*, type of iron chelating agents, or urine neutrophil gelatinase-associated lipocalin level.

Conclusions

CRS is relatively common in thalassemia patients. Its occurrence is associated with laboratory parameters which are easily measured in clinical practice.

Earlier Detection of Glomerular Dysfunction in β-Thalassemia Major Patients

Chronic transfusions program in β-thalassemia patients will inevitably lead to iron overload with a significant morbidity and mortality. Glomerular filtration rate (GFR) is progressively declined in relation to iron overload as well as chronic anemia. Objective is to define levels of Cystatin C in transfusion dependent β-thalassemia major patients as a sensitive marker for detection of earlier glomerular dysfunction in addition to understand the effect of iron overload, chelating therapy and hepatitis infection. A cross sectional study conducted at Al-Basrah Hemoglobinopathy Centre for the period from September 2017 to January 2018 to enroll 75 β-thalassemia major patients. Data collected included duration of the disease, total transfusion requirement, details of chelation therapy and its therapeutic index. In addition to blood urea, serum creatinine and Cystatin C with estimated GFR (eGFR). The mean Cystatin C was 1.075 mg/L where 66.6% of patients had abnormal renal function which is higher proportion than those with renal (42.6%) detected according to serum creatinine level Cystatin C was significantly higher in patients who received desferrioxamine as compared to those received deferasirox (p = 0.007), in accordance with GFR which is significantly higher in patients receiving the latter chelation therapy (p = 0.009). A significant inverse relationship between Cystatin C, and GFR, while positive relationship between ferritin and Cystatin C (p = 0.0001, 0.001 respectively). Cyctatin C is better for detection and monitoring of glomerular dysfunction in B thalassemia major patient which is already not uncommon complications for the disease and iron chelation therapy.

β2-Microglobulin, Neutrophil Gelatinase-Associated Lipocalin, and Endocan Values in Evaluating Renal Functions in Patients with β-Thalassemia Major

Chronic anemia, transfusion-associated iron deposition, and chelating agents lead to renal impairment in β-thalassemia (β-thal) patients. The present study aimed to determine the most reliable and practical method in assessing and predicting renal injury in β-thal major (β-TM) patients. Therefore, we assessed the predictive values of urine β2-microglobulin (β2-MG) and neutrophil gelatinase-associated lipocalin (NGAL) levels, their ratios to urine creatinine, and serum endocan level. Sixty β-TM patients and 30 healthy controls were included. Renal functions of the patients and controls were evaluated by means of urine protein/creatinine ratio, urine β2-MG, urine NGAL, and serum endocan level. The β-TM and control groups were comparable in terms of the demographic characteristics. Of the β-TM patients, 26.7% had glomerular hyperfiltration and 41.7% had proteinuria. Compared with the control group, the β-TM group had significantly higher levels of urine protein/creatinine, urine β2-MG, urine β2-MG/creatinine, urine NGAL, urine NGAL/creatinine, and serum endocan. These parameters did not differ between the chelating agent subgroups in the patient group. Urine β2-MG/creatinine and NGAL/creatinine ratios were the parameters with high specificity in predicting proteinuria. There were significant correlations of urine β2-MG, urine NGAL, and serum endocan levels with serum ferritin concentration. Urine β2-MG/creatinine, NGAL/creatinine, and protein/creatinine ratios were correlated with each other in the patient group. Positive correlations of urine β2-MG, urine NGAL, and serum endocan levels with serum ferritin concentration indicated that iron deposition was associated with endothelial damage and renal injury.

Renal failure in thalassemia: Thinking outside the box

Berger's disease should be considered an imperative cause of renal dysfunction in thalassemia. This case highlights the importance of early diagnosis, clinicopathological correlation and prompt therapy in Berger's disease.

Evaluation of Renal Function Disorder With Urinary Neutrophil Gelatinase-associated Lipocalin Level in Patients With β-Thalassemia Major

BACKGROUND AND AIM

Neutrophil gelatinase-associated lipocalin (NGAL) is found in the granules of human neutrophils, with many diverse functions. Expression of NGAL is induced under various pathophysiological conditions, for example, infection, inflammation, kidney injury, cardiovascular disease, burn injury, and intoxication, and it has an important antiapoptotic and anti-inflammatory role.

PATIENTS AND METHODS

A total of 37 patients with thalassemia disease β-thalassemia major (24 male and 13 female individuals) and 37 healthy controls (17 male and 20 female) were enrolled in this study. All patients were regularly transfused, and all of them were using oral chelator, deferasirox.

RESULTS

NGAL and cystatin C levels were significantly higher in the case group than in the control group.

CONCLUSION

In patients with β-thalassemia major, renal damage can occur owing to regular blood transfusion. Urinary NGAL levels in these patients may be considered as a marker for early renal injury.

Subclinical nephrotoxicity in patients with beta-thalassemia: role of urinary kidney injury molecule

We aimed to investigate the role of urinary kidney injury molecule-1 (KIM-1) in detection of subclinical nephrotoxicity in patients with Beta-thalassemia (β-TM) in relation to chelation therapy and to correlate the urinary KIM-1 level with other clinical and laboratory findings. We conducted a cross-sectional study on 66 thalassemic patients. Their ages range from 7 to 22 years. Routine kidney indices and novel urinary KIM/creatinine ratio (U_KIM-1/Cr) were measured. Estimated glomerular filtration rate (eGFR) was calculated. Results indicate that the level of serum creatinine was significantly higher in patients on deferasirox therapy than patients on deferoxamine and deferiprone therapy [median(IQR), 0.85(0.63-0.99), 0.50(0.34-0.58) and 0.44(0.36-0.45)] mg/dL, respectively, p < 0.001]. The median(IQR) level of eGFR was significantly lower in patients on deferasirox therapy than patients on deferoxamine and deferiprone therapy [63.3(56.5-92.1), 117.3(91.9-162) and 136.7(109.4-157.6)] ml/min/1.73 m², respectively, p < 0.001]. The mean level of U_KIM-1/Cr was significantly higher in patients on deferasirox therapy than patients on deferoxamine and deferiprone therapy (7.0 ± 1.9, 4.1 ± 1.7 and 4.2 ± 1.5) ng/mg creatinine, respectively, p < 0.001). We concluded that urinary KIM-1 is an early predictive biomarker for decline in eGFR in patients with β-TM on deferasirox therapy. The appropriate chelation therapy and good monitoring of those patients are intensely needed for early detection of renal dysfunction and timely intervention.

Beta-thalassemia: renal complications and mechanisms: a narrative review

OBJECTIVES

Beta-thalassemias are a group of recessively autosomal inherited disorders of hemoglobin synthesis, which, due to mutations of the beta-globin gene, lead to various degrees of defective beta-chain production, an imbalance in alpha/beta-globin chain synthesis, ineffective erythropoiesis, and anemia. Improved survival in thalassemic patients has led to the emergence of previously unrecognized complications, such as renal disease.

METHODS

A comprehensive literature review through PubMed was undertaken to summarize the published evidence on the epidemiology and pathophysiology of renal disease in thalassemia. Literature sources published in English since 1990 were searched, using the terms beta-thalassemia, renal disease.

RESULTS

Renal disease is considered to be the 4th cause of morbidity among patients with transfusion dependent thalassemia. Chronic anemia, hypoxia and iron overload are the main mechanisms implicated in development of renal injury, whereas several studies also suggested a contributive role of iron chelators.

DISCUSSION AND CONCLUSION

Kidney disease may develop through progressive renal tubular and glomerular damage; thus, its early recognition is important in order to prevent and/or reverse deterioration. This review will provide an insight on the involved mechanisms implicated in kidney disease in thalassemic patients and will discuss the updates on diagnosis and prevention of renal complications in thalassemia.

Early Predictors of Renal Dysfunction in Pediatric Patients with Sickle Cell Disease

Sickle cell disease (SCD) is a hereditary hemoglobinopathy characterized by abnormal hemoglobin production which leads to hemolytic anemia and intermittent occlusion of small blood vessels, which further leads to tissue ischemia, chronic organ damage, and organ dysfunction including urinary system. To measure the serum levels of cystatin-C and beta 2 microglobulin in pediatric patients with SCDand to investigate their significance as early biomarkers of glomerular and/or renal tubular dysfunction. This study was conducted among 70 children with SCD and 40 age and sex-matched children as a control group. All subjects underwent a full medical history, through physical examination, laboratory investigations including blood urea, serum creatinine, serum ferritin, estimated glomerular filtration rate (eGFR) using the Schwartz formula, creatinine clearance, urinary albumin/creatinine ratio, serum cystatin-C, and β-2 microglobulin levels. Pediatric patients with SCD had significantly higher serum cystatin-C and β-2 microglobulin levels compared to controls. In addition, serum cystatin-C and β-2 microglobulin levels were positively correlated with blood urea, serum creatinine, serum ferritin, urinary albumin/creatinine ratio, duration of iron chelating agents and frequency of blood transfusion/year. Serum cystatin-C and β-2 microglobulin levels were negatively correlated with hemoglobin. Our data concluded that serum cystatin-C and β-2 microglobulin had highersensitivity and specificity (91%, 90% and 85.7%, 100%, respectively) than serum creatinine (79% and85%, respectively). Serum Cystatin-C and β-2 microglobulin are early specific and sensitive biomarkers for evaluating glomerular and tubular dysfunction in children with SCD.

Thalassemia in the laboratory: pearls, pitfalls, and promises

Thalassemia is one of the most common hereditary disorders of the developing world, and it is associated with severe anemia and transfusion dependence. The global health burden of thalassemia has increased as a result of human mobility and migration in recent years. Depending on inherited mutations, thalassemia patients exhibit distorted hemoglobin (Hb) patterns and deviated red cell indices, both of which can be used to support identification by diagnostic tools. Diagnostic approaches vary depending on the target population and the aim of the testing. Current methods, which are based on Hb patterns, are used for first-line screening, whereas molecular testing is needed for conformation of the results and for prenatal and preimplantation genetic diagnosis. In the present paper, we review the diagnostic parameters, pitfalls, interfering factors, and methods; currently available best-practice guidelines; quality assurance and standardization of the procedures; and promising laboratory technologies for the future of thalassemia diagnosis.

Renal complications in thalassemia

Thalassemia is a disease with an extensive morbidity profile affecting almost every organ system. Renal involvement, once considered rare, is an underestimated and poorly studied complication that has been on the rise ever since medical advances granted patients longer life spans. Several studies and reports have emerged recently to shed light on the seriousness of this complication, although data is still lacking in terms of pathophysiology, diagnosis, prevention and treatment. In this review, we evaluate and compare renal involvement in the transfusion-dependent and independent variants of β-Thalassemia, highlighting the pathophysiology of kidney damage that involves iron overload, chronic anemia, and iron chelation therapy. An in-depth and focused review of the types of injuries incurred is also presented along with the diagnostic biomarkers accompanying each type of injury. Most research so far has focused on the transfusion-dependent thalassemia population being the group with most renal involvement, however recent reports have shown evidence of comparable, if not worse, involvement of the non-transfusion dependent population, sometimes leading to end-stage renal disease. As such, we try to shed light on distinct renal involvements in NTDT whenever available.

β-Thalassemia intermedia: a comprehensive overview and novel approaches

β-Thalassemia intermedia is a clinical condition of intermediate gravity between β-thalassemia minor, the asymptomatic carrier, and β-thalassemia major, the transfusion-dependent severe anemia. It is characterized by a significant clinical polymorphism, which is attributable to its genetic heterogeneity. Ineffective erythropoiesis, chronic anemia, and iron overload contribute to the clinical complications of thalassemia intermedia through stepwise pathophysiological mechanisms. These complications, including splenomegaly, extramedullary erythropoiesis, iron accumulation, leg ulcers, thrombophilia, and bone abnormalities can be managed via fetal hemoglobin induction, occasional transfusions, chelation, and in some cases, stem cell transplantation. Given its clinical diversity, thalassemia intermedia patients require tailored approaches to therapy. Here we present an overview and novel approaches to the genetic basis, pathophysiological mechanisms, clinical complications, and optimal management of thalassemia intermedia.

Role of serum cystatin-C and beta-2 microglobulin as early markers of renal dysfunction in children with beta thalassemia major

BACKGROUND

Although advancements have been made in the management of thalassemic patients, many unrecognized complications have emerged, such as renal abnormalities.

AIM

To measure serum levels of cystatin-C and β-2 microglobulin in children with beta-thalassemia major (β-TM) and investigate their significance as early markers of glomerular and tubular dysfunctions.

SUBJECTS AND METHODS

The study was performed on 70 children with (β-TM) and 20 apparently healthy children matched for age and sex as a control group. For all the enrolled children, a comprehensive medical history was obtained and complete physical examination was performed, blood urea, serum creatinine, serum ferritin, estimated glomerular filtration rate (eGFR) by Schwartz formula and creatinine clearance, albumin/creatinine ratio in urine, serum cystatin-C levels and β-2 microglobulin were measured.

RESULTS

Thalassemic children had significantly higher cystatin-C and β-2 microglobulin levels compared with control. In addition, serum cystatin-C and β-2 microglobulin were positively correlated with urea, creatinine, serum ferritin, albumin/creatinine ratio, duration of chelation therapy and frequency of blood transfusion/year and negatively correlated with creatinine clearance, hemoglobin, and eGFR. Our data demonstrated that cystatin-C and β-2 microglobulin had higher sensitivity and specificity (91.4%, 90.0%, and 85.7%, 100%, respectively) than serum creatinine and creatinine clearance (83.0%, 100% and 81.4%, 100%, respectively) for small changes in GFR.

CONCLUSION

Cystatin-C and β-2 microglobulin are specific and sensitive early biomarkers for monitoring glomerular and tubular dysfunction in children with β-TM.

Thalassemia-associated osteoporosis: a systematic review on treatment and brief overview of the disease

Thalassemia-associated osteoporosis constitutes a major complication in patients with thalassemia. This review presents the existing studies on the treatment of thalassemia-associated osteoporosis and discusses the management of this debilitating complication. A brief presentation of the disease characteristics and pathogenetic mechanisms is also provided. The life expectancy of patients with thalassemia has increased markedly in recent years resulting in the aging of the population and the emergence of new comorbidities. The majority of patients with thalassemia have low bone mineral density and experience lifelong fracture rates as high as 71 %. The pathogenesis of thalassemia-associated osteoporosis (TAO) is multifactorial with anemia and iron overload playing crucial role in its development. Data concerning the prevention and treatment of TAO are extremely limited. We performed a literature research in Pubmed and Scopus to identify interventional studies evaluating the effects of various agents on TAO. Seventeen studies were retrieved. We present the results of these studies as well as a brief overview of TAO including presentation, pathogenesis, and management. Most of the studies identified are of poor quality, are not randomized controlled, and include small number of participants. There are no data concerning effects on fracture rates. Bisphosphonates are the most widely studied agents and among them zoledronic acid is the most well studied. Hormone replacement treatment (HRT) shows beneficial but small effects. Denosumab and strontium ranelate have each been evaluated in only a single study, while there are no data about the effects of anabolic agents. Given the increased life expectancy and the increase in fracture rates with age, more data about the management of TAO are warranted. Moreover, due to the need for lifelong management starting at young age, careful treatment plans which may include sequential treatment may often be required. However, currently, there are no relevant data available.

Multidisciplinary evaluation at baseline and during treatment improves the rate of compliance and efficacy of deferasirox in elderly myelodysplastic patients

BACKGROUND

Deferasirox (DFX) is used to reduce iron levels in patients with myelodysplastic syndrome (MDS) who develop iron overload after chronic red blood cell infusions. However, DFX can be associated with renal and gastrointestinal toxicities, which may cause treatment interruption or discontinuation. This study aimed to determine the effectiveness and safety of DFX in patients with MDS.

METHODS

This multicenter, retrospective, observational study was conducted at two hospitals in Italy. Elderly patients with transfusion-dependent MDS received DFX for up to 12 months and were divided into two groups: group A comprised patients who were not under multidisciplinary assessment; group B comprised patients under multidisciplinary control. Treatment effectiveness was estimated by monitoring the serum ferritin (SF) levels throughout the study. Any treatment-related adverse events (AEs), clinically relevant analytical alterations, and reasons for treatment discontinuation were monitored.

RESULTS

The study included 44 patients (13 female, 31 male; median age 77.0 years). At 3 months, SF levels decreased by ≥20 % in 29 and 31 % of patients in groups A and B, respectively, in 17 and 36 % of patients at 6 months, and in 22 and 58 % at 12 months. The most common AEs were diarrhea and increased serum creatinine, which were more frequent in group A. The discontinuation rate after renal AE was 15 and 5 % in groups A and B, respectively.

CONCLUSION

Multidisciplinary evaluation can be an effective strategy for monitoring renal function in patients on DFX therapy, to improve treatment adherence and overall efficacy in elderly patients with MDS.

Glomerular and tubular functions in children with different forms of beta thalassemia

BACKGROUND

Although there are many available data about renal involvement in patients with beta thalassemia major (TM), the changes in renal functions of other types, such as thalassemia intermedia (TI) and thalassemia minor (TMin), were reported less. Therefore, we aimed to evaluate renal tubular and glomerular functions in patients with three types of beta thalassemia.

METHODS

This prospective case-control study was conducted on 118 beta-thalassemia patients (49 in TM, 18 in TI and 51 TMin) and 51 healthy controls. Glomerular functions [estimated glomerular filtration rate (GFR), serum cystatin C and urinary protein creatinine ratio] and tubular functions [fractioned sodium excretion (FENa), tubular reabsorption of phosphorus, urinary excretion of uric acid, levels of retinol-binding protein, alpha-1 macroglobulin (alpha-1M), and beta-2 microglobulin, calcium creatinine ratio] were assessed in all patients and controls.

RESULTS

The mean ages of the groups and controls at presentation were similar. Although GFR was similar in all patients and control groups, serum levels of cystatin C in patients with TM and TI were significantly higher compared to TMin and controls. Alpha-1M, FENa, urinary excretion of uric acid, and urine protein/creatinine ratio in TM and TI groups were significantly higher than the others. Mean cystatin C level was also higher in patients with TMin compared the controls. However, there were no significant differences according to all tubular and other glomerular functions between TMin and control groups.

CONCLUSIONS

Although all types of beta thalassemia patients should be closely monitored to prevent further decrease in renal functions, the patients with TI should be considered to have a higher risk of glomerular and tubular deterioration as well as TM.

GFR in Patients with β-Thalassemia Major

BACKGROUND AND OBJECTIVES

Patients with β-thalassemia major (TM) may have tubular dysfunction and glomerular dysfunction, primarily hyperfiltration, based on eGFR. Assessment of GFR based on serum creatinine concentration may overestimate GFR in these patients. This study sought to determine GFR by using inulin clearance and compare it with measured creatinine clearance (Ccr) and eGFR.

DESIGN, SETTING, PARTICIPANTS & MEASUREMENTS

Patients followed up in an Israeli thalassemia clinic who had been regularly transfused for years and treated with deferasirox were included in the study. They were studied by inulin clearance, Ccr, the CKD Epidemiology Collaboration and the Modification of Diet in Renal Disease equations for eGFR, and the Cockcroft-Gault estimation for Ccr. Expected creatinine excretion rate and tubular creatinine secretion rate were calculated.

RESULTS

Nine white patients were studied. Results, given as medians, were as follows: serum creatinine was 0.59 mg/dl (below normal limits); GFR was low (76.6 ml/min per 1.73 m(2)) and reached the level of CKD; Ccr was 134.9 ml/min per 1.73 m(2), higher than the GFR because of a tubular creatinine secretion rate of 30.3 ml/min per 1.73 m(2) (this accounted for 40% of the Ccr); and eGFR calculated by the CKD Epidemiology Collaboration and Modification of Diet in Renal Disease equations and Cockcroft-Gault-estimated Ccr were 133, 141, and 168 ml/min per 1.73 m(2), respectively. These latter values were significantly higher than the GFR, reaching the hyperfiltration range, and indicated that the estimation techniques were clinically unacceptable as a method for measuring kidney function compared with the GFR according to Bland and Altman analyses.

CONCLUSIONS

Contrary to previous reports, patients in this study with TM had normal or reduced GFR. The estimating methods showed erroneous overestimation of GFR and were clinically unacceptable for GFR measurements in patients with TM by Bland and Altman analysis. Therefore, more accurate methods should be used for early detection of reduced GFR and prevention of its further decline toward CKD in these patients.

Urinary early kidney injury molecules in children with beta-thalassemia major

BACKGROUND

The aim of this study was to investigate novel urinary biomarkers including N-acetyl-β-D-glucosaminidase (NAG), neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), and liver-type fatty acid binding protein (L-FABP) in children with β-thalassemia major (β-TM).

MATERIALS AND METHODS

Totally, 52 patients (29 boys, 23 girls) with β-TM and 29 healthy controls (3-17 years) were included. Various demographic characteristics and blood transfusions/year, disease duration, and chelation therapy were recorded. Serum urea, creatinine, electrolytes, and ferritin and urinary creatinine, protein, calcium, phosphorus, sodium, potassium, and uric acid in first morning urine samples were measured and estimated glomerular filtration rate (eGFR) was calculated. Routine serum and urinary biochemical variables, urinary NAG to Creatinine (U(NAG/Cr)), U(NGAL/Cr), U(KIM-1/Cr), and U(L-FABP/Cr) ratios were determined.

RESULTS

Patients had similar mean serum urea, creatinine and eGFR levels compared with controls (p > 0.05 for all). The mean urinary protein to creatinine (U(Protein/Cr)) ratio was significantly higher in patients compared to the healthy subjects (0.13 ± 0.09 mg/mg and 0.07 ± 0.04 mg/mg, respectively; p < 0.001). Significantly increased U(NAG/Cr) (0.48 ± 0.58 vs. 0.23 ± 0.16, p = 0.026) and U(NGAL/Cr) (22.1 ± 18.5 vs. 11.5 ± 6.17, p = 0.01) ratios were found in β-TM patients compared with healthy controls. However, no differences were found in serum and urinary electrolytes or U(KIM-1/Cr) and U(L-FABP/Cr) ratios between patients and controls (p > 0.05). Significant correlations were found between urinary biomarkers and urinary electrolytes (p < 0.05).

CONCLUSIONS

Our results suggest that urinary NAG and NGAL may be considered to be reliable markers to monitor renal injury in β-TM patients.

Deferasirox effect on renal haemodynamic parameters in patients with transfusion-dependent β thalassaemia

Some patients with β thalassaemia experience non-progressive creatinine increases with deferasirox, mostly within normal limits; the mechanisms involved are not fully elucidated. The effects of deferasirox on renal haemodynamics, including glomerular filtration rate (GFR) and renal plasma flow (RPF), were investigated in a Phase I, open-label study in β thalassaemia major patients with iron overload. Patients received deferasirox 30 mg/kg/d up to Week 8, followed by a 2-week washout period, and extended treatment up to Week 104 with a 4-week washout period. In the short-term study (n = 11), mean GFR and RPF declined from baseline to Week 8 (mean [%] change:-9·2 [-9·5%] and -105·7 ml/min [-17·8%], respectively). A similar pattern was observed during the long-term study (n = 5); mean GFR and RPF decreased up to Week 52 (-19·1 [-17·7%] and -155·6 ml/min [-26·1%]), with similar change at Week 104 (-18·4 [-17·2%] and -115·9 ml/min [-19·6%]). Measures returned to baseline values after each washout. Serum creatinine and creatinine clearance followed a similar pattern. Effects of deferasirox on renal haemodynamics were mild and reversible for up to 2 years of treatment, with no progressive worsening of renal function over time. www.clinicaltrials.gov: NCT00560820.

Early Predictors of Renal Dysfunction in Egyptian Patients with β-Thalassemia Major and Intermedia

Background

Better survival of thalassemia patients allowed previously unrecognized renal complications to emerge.

Objectives

Assess prevalence and early predictors of renal dysfunction in young β-thalassemia major (β-TM) and intermedia (β-TI) patients.

Subjects

66 β-TM (group I), 26 β-TI (group II) Egyptian patients and 40 healthy controls.

Methods

Clinical assessment and laboratory data including kidney and liver function tests, such as serum ferritin, serum bicarbonate, plasma osmolality and urinary total proteins, microalbuminuria (MAU), N-acetyl-β-D-glucosaminidase (NAG), retinol binding protein (RBP), α-1 microglobulin, bicarbonate, osmolality, creatinine clearance (CrCl), % fractional excretion of bicarbonate (% FE-HCO3).

Results

The prevalent renal abnormality was proteinuria (71%), followed by increased urinary level of RBP (69.4%), NAG (58.1%), α-1 microglobulin (54.8%) and microalbuminuria (29%) and also decreased urinary osmolality (58.1%). CrCl was a better assessment of renal function and significantly lowered in thalassemia patients. Tubular dysfunctions were more significant in splenectomized β-TM patients who showed more elevation of NAG and α-1 microglobulin and lower urinary osmolality. NAG, RBP and α-1 microglobulin were negatively correlated with CrCl and positively correlated with serum ferritin and urinary total protein. Z-score analysis for identifying patients with renal dysfunction proved superiority of urine total protein and RBP. Comparative statistics of different frequencies revealed significant difference between the urinary total protein and both MAU and % FE-HCO3.

Conclusion

Asymptomatic renal dysfunctions are prevalent in young β-TM and β-TI patients that necessitate regular screening. Urinary total protein and RBP may be cost-effective for early detection.

Novel approach to reactive oxygen species in nontransfusion-dependent thalassemia

The term Nontransfusion dependent thalassaemia (NTDT) was suggested to describe patients who had clinical manifestations that are too severe to be termed minor yet too mild to be termed major. Those patients are not entirely dependent on transfusions for survival. If left untreated, three main factors are responsible for the clinical sequelae of NTDT: ineffective erythropoiesis, chronic hemolytic anemia, and iron overload. Reactive oxygen species (ROS) generation in NTDT patients is caused by 2 major mechanisms. The first one is chronic hypoxia resulting from chronic anemia and ineffective erythropoiesis leading to mitochondrial damage and the second is iron overload also due to chronic anemia and tissue hypoxia leading to increase intestinal iron absorption in thalassemic patients. Oxidative damage by reactive oxygen species (generated by free globin chains and labile plasma iron) is believed to be one of the main contributors to cell injury, tissue damage, and hypercoagulability in patients with thalassemia. Independently increased ROS has been linked to a myriad of pathological outcomes such as leg ulcers, decreased wound healing, pulmonary hypertension, silent brain infarcts, and increased thrombosis to count a few. Interestingly many of those complications overlap with those found in NTDT patients.

Use of deferasirox in transfusion-dependent myelodysplastic syndromes with iron overload

SUMMARY 

In myelodysplastic syndromes (MDS), transfusion-dependent anemia has been established as an independent risk factor for decreased survival. Although evidence from prospective studies is still lacking, several guidelines recommend iron-chelating therapy in MDS patients with a longer life expectancy. With the recent introduction of deferasirox, an oral active iron-chelating drug, which has shown dose-dependent efficacy and acceptable tolerability, this therapeutic option has become feasible even in the elderly. Several retrospective and prospective studies showed that in MDS patients deferasirox is effective in reducing iron burden and in maintaining the circulating toxic iron fraction within the normal range. Moreover, in a substantial fraction of patients treated with deferasirox a significant improvement of peripheral cytopenias may occur.

Thalassemia bone disease: the association between nephrolithiasis, bone mineral density and fractures

Thalassemia bone disease is well described, but the prevalence of nephrolithiasis has not been characterized. The association between nephrolithiasis, reduced bone density, and increased fractures has been demonstrated through this retrospective study of 166 participants with transfusion-dependent thalassemia. The findings support the need for increased vigilance of kidney and bone disease in this cohort.

INTRODUCTION

Previous studies have revealed that thalassemia is associated with reduced bone mineral density (BMD) and fractures. Many causes are implicated including hypogonadism, growth hormone deficiency, marrow expansion, and iron overload. Nephrolithiasis is associated with reduced BMD and increased fractures in the general population. However, the prevalence of nephrolithiasis and its association with bone density and fractures have not been characterized in thalassemia.

METHODS

We have addressed this question by performing a retrospective cohort study of 166 participants with transfusion-dependent thalassemia who had undergone dual-energy X-ray absorptiometry between 2009 and 2011. Logistic regression modeling was used to adjust for potential confounders.

RESULTS

We found a high prevalence of kidney stones (18.1 %) which was greater in males compared to females (28.7 vs 9.7 %, respectively). Renal stones were associated with reduced femoral neck Z-score and fractures in men after adjusting for potential confounders. These results indicate that nephrolithiasis is highly prevalent in patients with transfusion-dependent thalassemia and is significantly associated with reduced BMD and increased fractures.

CONCLUSIONS

The findings from this study strongly support the need for ongoing surveillance of BMD, fractures, and nephrolithiasis in the management of transfusion-dependent thalassemia.

Safety and efficacy of deferasirox in the management of transfusion-dependent patients with myelodysplastic syndrome and aplastic anaemia: a perspective review

Deferasirox is an orally administered, once-daily iron chelator with a generally good safety and efficacy profile. Reported adverse events in the older myelodysplastic population are somewhat different to the more intensively investigated and younger thalassaemic population. Renal impairment is the most concerning adverse event, but this is reversible if identified and the drug is withdrawn early. Gastrointestinal effects, particularly diarrhoea, can be troublesome for older patients, but can be minimized with tailored therapy. Negative iron balance can be achieved in most patients with a median dose of 20 mg/kg/day, and doses up to 40 mg/kg are possible in patients with severe iron overload, who are at risk of cardiac decompensation.

Assessment and management of iron overload in β-thalassaemia major patients during the 21st century: a real-life experience from the Italian WEBTHAL project

We conducted a cross-sectional study on 924 β-thalassaemia major patients (mean age 30·1 years) treated at nine Italian centres using the WEBTHAL software, to evaluate real-life application of iron overload assessment and management standards. Serum ferritin <2500 ng/ml was a risk factor for never having liver iron concentration (LIC) measurement, while absence of cardiac disease and siderosis were risk factors for a delay in LIC measurement >2 years. Patients who never had a cardiac MRI (CMR) T2* measurement were <18 years, had iron intake ≤0·4 mg/kg per day, or a serum ferritin <2500 ng/ml. A history of normal CMR T2* was the main risk factor for a delay in subsequent assessment of >2 years. Deferoxamine (22·8%) was more commonly used in patients with Hepatitis C Virus or high serum creatinine. Deferiprone (20·6%) was less commonly prescribed in patients with elevated alanine aminotransferase; while a deferoxamine + deferiprone combination (17·9%) was more commonly used in patients with serum ferritin >2500 ng/ml or CMR T2* <20 ms. Deferasirox (38·3%) was more commonly prescribed in patients <18 years, but less commonly used in those with heart disease or high iron intake. These observations largely echoed guidelines at the time, although some practices are expected to change in light of evolving evidence.