Serum ferritin in the diagnosis of cardiac and liver iron overload in thalassaemia patients real-world practice: a multicentre study

Cellular and animal models for the investigation of β-thalassemia

β-Thalassemia is a genetic form of anemia due to mutations in the β-globin gene, that leads to ineffective and extramedullary erythropoiesis, abnormal red blood cells and secondary iron-overload. The severity of the disease ranges from mild to lethal anemia based on the residual levels of globins production. Despite being a monogenic disorder, the pathophysiology of β-thalassemia is multifactorial, with different players contributing to the severity of anemia and secondary complications. As a result, the identification of effective therapeutic strategies is complex, and the treatment of patients is still suboptimal. For these reasons, several models have been developed in the last decades to provide experimental tools for the study of the disease, including erythroid cell lines, cultures of primary erythroid cells and transgenic animals. Years of research enabled the optimization of these models and led to decipher the mechanisms responsible for globins deregulation and ineffective erythropoiesis in thalassemia, to unravel the role of iron homeostasis in the disease and to identify and validate novel therapeutic targets and agents. Examples of successful outcomes of these analyses include iron restricting agents, currently tested in the clinics, several gene therapy vectors, one of which was recently approved for the treatment of most severe patients, and a promising gene editing strategy, that has been shown to be effective in a clinical trial. This review provides an overview of the available models, discusses pros and cons, and the key findings obtained from their study.

Accelerated atherosclerosis in beta-thalassemia

Children with beta-thalassemia (BT) present with an increase in carotid intima-medial thickness, an early sign suggestive of premature atherosclerosis. However, it is unknown if there is a direct relationship between BT and atherosclerotic disease. To evaluate this, wild-type (WT, littermates) and BT (Hbbth3/+) mice, both male and female, were placed on a 3-mo high-fat diet with low-density lipoprotein receptor suppression via overexpression of proprotein convertase subtilisin/kexin type 9 (PCSK9) gain-of-function mutation (D377Y). Mechanistically, we hypothesize that heme-mediated oxidative stress creates a proatherogenic environment in BT because BT is a hemolytic anemia that has increased free heme and exhausted hemopexin, heme's endogenous scavenger, in the vasculature. We evaluated the effect of hemopexin (HPX) therapy, mediated via an adeno-associated virus, to the progression of atherosclerosis in BT and a phenylhydrazine-induced model of intravascular hemolysis. In addition, we evaluated the effect of deferiprone (DFP)-mediated iron chelation in the progression of atherosclerosis in BT mice. Aortic en face and aortic root lesion area analysis revealed elevated plaque accumulation in both male and female BT mice compared with WT mice. Hemopexin therapy was able to decrease plaque accumulation in both BT mice and mice on our phenylhydrazine (PHZ)-induced model of hemolysis. DFP decreased atherosclerosis in BT mice but did not provide an additive benefit to HPX therapy. Our data demonstrate for the first time that the underlying pathophysiology of BT leads to accelerated atherosclerosis and shows that heme contributes to atherosclerotic plaque development in BT.NEW & NOTEWORTHY This work definitively shows for the first time that beta-thalassemia leads to accelerated atherosclerosis. We demonstrated that intravascular hemolysis is a prominent feature in beta-thalassemia and the resulting increases in free heme are mechanistically relevant. Adeno-associated virus (AAV)-hemopexin therapy led to decreased free heme and atherosclerotic plaque area in both beta-thalassemia and phenylhydrazine-treated mice. Deferiprone-mediated iron chelation led to deceased plaque accumulation in beta-thalassemia mice but provided no additive benefit to hemopexin therapy.

Race-neutral equations for assessment of lung function in children with thalassemia

The aim of this study was to assess pulmonary dysfunction in children with transfusion-dependent thalassemia (TDT) using the Global Lung Function Initiative (GLI) 2022 race-neutral spirometric reference equations and to determine the main predicting factors. The spirometric results of 68 children with TDT were compared to the results of 68 healthy control subjects using both GLI-2012 reference equations for Caucasians and GLI-2022 global equations. Associations between the spirometric data and various anthropometric, clinical, and laboratory parameters were analyzed to detect predictors of pulmonary dysfunction in this group of patients. Children with TDT showed significantly lower values of FVC and FEV1 with a predominance of the restrictive pattern (23.53%). Thalassemic children with the restrictive pattern were significantly older, had a longer duration of regular blood transfusion, lower height, weight, and BMI z-scores, higher average serum ferritin, and higher frequency of having a serum ferritin level >2500 ng/mL. The strongest predictor for having a restrictive spirometric pattern was high serum ferritin. Our analysis shows that the transition from GLI-2012 spirometric reference equations for Caucasians to the GLI-2022 global equations has led to a reduction in the prevalence rate of restrictive pulmonary dysfunction in children with TDT, which should not affect the patient outcome in the long term. Asymptomatic children with TDT exhibited a restrictive spirometric pattern in a significant proportion. The most important predictor was high serum ferritin. We encourage the inclusion of pulmonary function testing in the routine monitoring of patients with TDT, especially in older patients and those with iron overload.

Optimized serum ferritin prediction of iron overload in transfusion-dependent thalassemia: likelihood ratio and age-adjustment approach

BACKGROUND

Early detection of iron overload in transfusion-dependent thalassemia (TDT) patients is critical to prevent complications and improve survival.

OBJECTIVES

Evaluate the utility of serum ferritin (SF) in the prediction of hepatic and myocardial iron overload (HIO and MIO) compared to T2*-MRI.

DESIGN

Retrospective SETTINGS: Governmental hospitals.

PATIENTS AND METHODS

Patients with TDT who had T2*-MRI examinations between January 2016 to October 2019 were included. The predictive value of SF for detection of HIO and MIO was assessed by measuring area under the curve (AUC). A sample size of 123 cases was calculated to detect a correlation of 0.25 with 90% power and a two-sided type I error of 0.05.

MAIN OUTCOME MEASURES

The correlation between SF and estimated hepatic iron concentration.

SAMPLE SIZE

137 TDT patients who required regular blood transfusions.

RESULTS

The predictive value of SF was excellent for detection of HIO (AUC=0.83-0.87) but fair for detection of MIO (AUC=0.67). The two independent predictors of MIO were age and SF. The log of (age × SF) enhanced the SF predictive value for MIO (AUC=0.78). SF values of 700 and 1250 mg/L effectively excluded mild and moderate HIO with a sensitivity of 97.8% and 94.2%, respectively (LR-=0.1). While SF values of 1640 and 2150 mg/L accurately diagnosed mild and moderate HIO with a specificity of 95.55% and 96.4%, respectively (LR+>10). A log of (age × SF) cut-off value of 4.15 effectively excluded MIO (LR-=0.1), while a value of 4.65 moderately confirmed MIO (LR+=3.2).

CONCLUSIONS

SF is an excellent predictor of hepatic IO in TDT. Age adjustment enhanced its myocardial IO predictive accuracy. Likelihood ratio-based SF cut-off values may help clinicians in risk stratification and treatment decision-making.

LIMITATIONS

The laboratory data were gathered retrospectively and although the risk of selection bias for T2*-MRI examination is thought to be low, it cannot be ignored.

CONFLICT OF INTEREST

None.

Drug-related problems among transfusion-dependent thalassemia patients: A real-world evidence study

Introduction: Thalassemia is among the most common genetic disorders globally and many patients suffer from iron overload (IOL) complications that mainly affect the heart, liver and endocrine system. These events may be further complicated by drug-related problems (DRP), an inherent issue among patients with chronic diseases. Objective: The study aimed to evaluate the burden, associated factors and impacts of DRP in transfusion-dependent thalassemia (TDT) patients. Method: Eligible TDT patients under follow-up in a tertiary hospital between 01 March 2020 to 30 April 2021 were interviewed and their medical records were reviewed retrospectively to identify any DRP. DRPs were classified using the Pharmaceutical Care Network Europe (PCNE) classification version 9.1. The incidence and preventability of DRP were assessed and the associated risk factors were estimated by univariate and multivariate logistic regression. Results: A total of 200 patients were enrolled with a median (interquartile range: IQR) age of 28 years at enrolment. Approximately 1 in 2 patients were observed to suffer from thalassemia-related complications. Throughout the study period, 308 DRPs were identified among 150 (75%) participants, with a median DRP per participant of 2.0 (IQR 1.0-3.0). Of the three DRP dimensions, treatment effectiveness was the most common DRP (55.8%) followed by treatment safety (39.6%) and other DRP (4.6%). The median serum ferritin level was statistically higher in patients with DRP compared with patients without DRP (3833.02 vs. 1104.98 μg/L, p < 0.001). Three risk factors were found to be significantly associated with the presence of DRP. Patients with frequent blood transfusion, moderate to high Medication Complexity Index (MRCI) and of Malay ethnicity were associated with higher odds of having a DRP (AOR 4.09, 95% CI: 1.83, 9.15; AOR 4.50, 95% CI: 1.89, 10.75; and AOR 3.26, 95% CI: 1.43, 7.43, respectively). Conclusion: The prevalence of DRP was relatively high amongst TDT patients. Increased medication complexity, more severe form of the disease and Malay patients were more likely to experience DRP. Hence, more viable interventions targeted to these groups of patients should be undertaken to mitigate the risk of DRP and achieve better treatment outcomes.

Ferritin thresholds for cardiac and liver hemosiderosis in β-thalassemia patients: a diagnostic accuracy study

Ferritin is frequently used to screen some dire consequences of iron overload in β-thalassemia patients. The study aimed to define the best cutoff point of ferritin to screen for cardiac and liver hemosiderosis in these cases. This was a registry-based study on β-thalassemia patients living throughout Mazandaran province, Iran (n = 1959). In this diagnostic research, the index test was ferritin levels measured by a chemiluminescent immunoassay. As a reference test, T2*-weighted magnetic resonance imaging (T2*-weighted MRI) was applied to determine cardiac and liver hemosiderosis. A cutoff point of 2027 ng/mL for ferritin showed a sensitivity of 50%, specificity 77.4%, PPV 42.1%, and NPV 82.5% for cardiac hemosiderosis (area under curve [AUC] 0.66, 95% CI 0.60-0.71, adjusted odds ratio [OR] 2.05, 95% CI 1.05-4.01). At an optimum cutoff point of 1090 ng/mL, sensitivity 66.7%, specificity 68%, PPV 82.9%, and NPV 46.8% for liver hemosiderosis were estimated (AUC 0.68, 95% CI 0.63-0.73, adjusted OR 3.93, 95% CI 2.02-7.64. The likelihood of cardiac hemosiderosis serum ferritin levels below 2027 ng/mL is 17.5%. Moreover, 82.9% of β-thalassemia patients with serum ferritin levels above 1090 ng/mL may suffer from liver hemosiderosis, regardless of the grades.

Bleeding Versus Thrombotic Tendency in Young Children With Beta-Thalassemia Major

Introduction

Bleeding and thrombotic events are known to occur in beta-thalassemia major (BTM) patients and have been attributed to hepatic iron overload associated with multiple blood transfusions. We evaluated hemostatic parameters in children with BTM who had no previous history of bleeding or thrombotic episodes.

Materials and Methods

Hemostatic parameters including prothrombin time (PT), activated partial thromboplastin time (APTT), platelet aggregation, protein C and S, iron profile, and liver function tests were evaluated in 54 children (median age = 12 months, age range = 4-144 months) with BTM and 15 age and sex-matched controls.

Results

The mean PT and APTT of patients were significantly higher (P=0.016 and P <.001) than that of controls. Mean protein C, protein S activity and platelet aggregability with adenosine 5-diphosphate (ADP) as an agonist in patients were significantly lower (P <.001, P <.001 and P=0.007, respectively) than that in controls. Mean serum ferritin in BTM children was not significantly elevated to be associated with hepatic dysfunction.

Conclusion

Deranged hemostatic parameters indicative of bleeding and thrombotic tendencies are observed in BTM children from an early age and may not be solely due to hyperferritinemia-associated hepatic dysfunction. Despite the presence of deranged hemostatic parameters, a state of balance exists between bleeding and thrombosis, and an imbalance may lead to bleeding or thrombotic events at a later age.

The effect of zinc deficiency and iron overload on endocrine and exocrine pancreatic function in children with transfusion-dependent thalassemia: a cross-sectional study

BACKGROUND

Children with transfusion-dependent thalassemia (TDT) suffer from secondary hemosiderosis and the delirious effects this iron overload has on their different body organs, including the pancreas. They are also more prone to develop zinc deficiency than the general pediatric population. This study aimed to determine the effect of zinc deficiency and iron overload on the endocrine and exocrine pancreas in TDT children.

METHODS

Eighty children, already diagnosed with TDT, were included in this study. We assessed the following in the participant children: serum ferritin, serum zinc, endocrine pancreatic function (oral glucose tolerance test (OGTT), fasting insulin level and from them, HOMA-IR was calculated), and exocrine pancreatic function (serum lipase and serum amylase).

RESULTS

Forty-four TDT children had a subnormal zinc level, while 36 of them had a normal serum zinc level. TDT children with low serum zinc had significantly more impaired endocrine pancreatic function and an abnormally high serum lipase than children with normal serum zinc, p < 0.05 in all. Serum zinc was significantly lower in TDT children with serum ferritin above the ferritin threshold (≥2500 ng/ml) than those below (59.1 ± 20.2 vs. 77.5 ± 28.13), p = 0.02. TDT children, having a serum ferritin ≥2500 ng/ml, had significantly more frequently impaired endocrine pancreatic function and abnormally high serum lipase than TDT children below the ferritin threshold, p < 0.05 in all.

CONCLUSION

In children with transfusion-dependent thalassemia, zinc deficiency aggravates iron-induced pancreatic exocrine and endocrine dysfunction.

Serum or plasma ferritin concentration as an index of iron deficiency and overload

BACKGROUND

Reference standard indices of iron deficiency and iron overload are generally invasive, expensive, and can be unpleasant or occasionally risky. Ferritin is an iron storage protein and its concentration in the plasma or serum reflects iron stores; low ferritin indicates iron deficiency, while elevated ferritin reflects risk of iron overload. However, ferritin is also an acute-phase protein and its levels are elevated in inflammation and infection. The use of ferritin as a diagnostic test of iron deficiency and overload is a common clinical practice.

OBJECTIVES

To determine the diagnostic accuracy of ferritin concentrations (serum or plasma) for detecting iron deficiency and risk of iron overload in primary and secondary iron-loading syndromes.

SEARCH METHODS

We searched the following databases (10 June 2020): DARE (Cochrane Library) Issue 2 of 4 2015, HTA (Cochrane Library) Issue 4 of 4 2016, CENTRAL (Cochrane Library) Issue 6 of 12 2020, MEDLINE (OVID) 1946 to 9 June 2020, Embase (OVID) 1947 to week 23 2020, CINAHL (Ebsco) 1982 to June 2020, Web of Science (ISI) SCI, SSCI, CPCI-exp & CPCI-SSH to June 2020, POPLINE 16/8/18, Open Grey (10/6/20), TRoPHI (10/6/20), Bibliomap (10/6/20), IBECS (10/6/20), SCIELO (10/6/20), Global Index Medicus (10/6/20) AIM, IMSEAR, WPRIM, IMEMR, LILACS (10/6/20), PAHO (10/6/20), WHOLIS 10/6/20, IndMED (16/8/18) and Native Health Research Database (10/6/20). We also searched two trials registers and contacted relevant organisations for unpublished studies.

SELECTION CRITERIA

We included all study designs seeking to evaluate serum or plasma ferritin concentrations measured by any current or previously available quantitative assay as an index of iron status in individuals of any age, sex, clinical and physiological status from any country.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methods. We designed the data extraction form to record results for ferritin concentration as the index test, and bone marrow iron content for iron deficiency and liver iron content for iron overload as the reference standards. Two other authors further extracted and validated the number of true positive, true negative, false positive, false negative cases, and extracted or derived the sensitivity, specificity, positive and negative predictive values for each threshold presented for iron deficiency and iron overload in included studies. We assessed risk of bias and applicability using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 tool. We used GRADE assessment to enable the quality of evidence and hence strength of evidence for our conclusions.

MAIN RESULTS

Our search was conducted initially in 2014 and updated in 2017, 2018 and 2020 (10 June). We identified 21,217 records and screened 14,244 records after duplicates were removed. We assessed 316 records in full text. We excluded 190 studies (193 records) with reasons and included 108 studies (111 records) in the qualitative and quantitative analysis. There were 11 studies (12 records) that we screened from the last search update and appeared eligible for a future analysis. We decided to enter these as awaiting classification. We stratified the analysis first by participant clinical status: apparently healthy and non-healthy populations. We then stratified by age and pregnancy status as: infants and children, adolescents, pregnant women, and adults. Iron deficiency We included 72 studies (75 records) involving 6059 participants. Apparently healthy populations Five studies screened for iron deficiency in people without apparent illness. In the general adult population, three studies reported sensitivities of 63% to 100% at the optimum cutoff for ferritin, with corresponding specificities of 92% to 98%, but the ferritin cutoffs varied between studies. One study in healthy children reported a sensitivity of 74% and a specificity of 77%. One study in pregnant women reported a sensitivity of 88% and a specificity of 100%. Overall confidence in these estimates was very low because of potential bias, indirectness, and sparse and heterogenous evidence. No studies screened for iron overload in apparently healthy people. People presenting for medical care There were 63 studies among adults presenting for medical care (5042 participants). For a sample of 1000 subjects with a 35% prevalence of iron deficiency (of the included studies in this category) and supposing a 85% specificity, there would be 315 iron-deficient subjects correctly classified as having iron deficiency and 35 iron-deficient subjects incorrectly classified as not having iron deficiency, leading to a 90% sensitivity. Thresholds proposed by the authors of the included studies ranged between 12 to 200 µg/L. The estimated diagnostic odds ratio was 50. Among non-healthy adults using a fixed threshold of 30 μg/L (nine studies, 512 participants, low-certainty evidence), the pooled estimate for sensitivity was 79% with a 95% confidence interval of (58%, 91%) and specificity of 98%, with a 95% confidence interval of (91%, 100%). The estimated diagnostic odds ratio was 140, a relatively highly informative test. Iron overload We included 36 studies (36 records) involving 1927 participants. All studies concerned non-healthy populations. There were no studies targeting either infants, children, or pregnant women. Among all populations (one threshold for males and females; 36 studies, 1927 participants, very low-certainty evidence): for a sample of 1000 subjects with a 42% prevalence of iron overload (of the included studies in this category) and supposing a 65% specificity, there would be 332 iron-overloaded subjects correctly classified as having iron overload and 85 iron-overloaded subjects incorrectly classified as not having iron overload, leading to a 80% sensitivity. The estimated diagnostic odds ratio was 8.

AUTHORS' CONCLUSIONS

At a threshold of 30 micrograms/L, there is low-certainty evidence that blood ferritin concentration is reasonably sensitive and a very specific test for iron deficiency in people presenting for medical care. There is very low certainty that high concentrations of ferritin provide a sensitive test for iron overload in people where this condition is suspected. There is insufficient evidence to know whether ferritin concentration performs similarly when screening asymptomatic people for iron deficiency or overload.

Time to Start Delivering Iron Chelation Therapy in Newly Diagnosed Severe β-Thalassemia

Background

Iron overload is still a major complication of severe β-thalassemia. Indication to start iron chelation therapy is based on serum ferritin (SF) or transferrin saturation (TS) level or the amount of transfusion. The goal of this study is to analyse the pattern of iron status, the amount of transfusion regarding the time to start iron chelator, and serum hepcidin levels in newly diagnosed severe β-thalassemia.

Methods

A prospective cohort study was performed at Hasan Sadikin General Hospital on newly diagnosed severe β-thalassemia patients. Subjects had not received any blood transfusion with normal liver function test, CRP, and IL-6 levels who consumed normal diet according to age. The SF and TS levels indicate iron status, while hepcidin level indicates iron regulator status. Main indicator to start iron chelation therapy when SF level ≥1.000 ng/mL, TS level ≥70%, or after receiving transfusion at least 10 times. Statistical analysis used Mann–Whitney and Spearman.

Results

Forty-two newly severe β-thalassemia, 30 (71.4%), were diagnosed before 1 year old, mean 9.9 ± 6.4 months, range 2–24 months. Range amount of transfusion until SF level reached ≥1,000 ng/mL were 4-12 times, mean 7 ± 2 times. Mean SF and TS level at diagnosis were 365.6 ± 194.9 ng/mL and 67.3 ± 22.5%, while hepcidin level was normal, mean 242.6 ± 58 ng/mL. 36/42 patients have reached SF >1000 ng/mL with amount of transfusion less than 10 times. There was no significant difference of SF, TS, and hepcidin levels when SF >1000 ng/mL in the group with amount of transfusion 7–12 and less than 7 (p = 0.454, p = 0.084, p = 0.765), respectively. A significant positive correlation between SF and amount of transfusion was observed (p < 0.001; r = 0.781).

Conclusion

Iron overload in severe β-thalassemia patients might occur earlier even before they received 10 times transfusion. Hepcidin serum level tends to increase when iron overload just started.

Correlation between Serum Ferritin Levels and Liver Stiffness measured by Fibroscan in patients with Chronic Hepatitis C

Objective

To determine correlation between transient elastography values with serum ferritin and duration of infection in patients of hepatitis C.

Methods

A cross-sectional study was conducted at medical units of Civil Hospital, Karachi. The study protocol was approved by the Research Evaluation Unit of College of Physician and Surgeon Pakistan (CPSP). Patients fulfilling inclusion criteria were included after taking informed consent. Serum ferritin levels were tested by standard laboratory procedures and transient elastography by fibroscan. Regression analysis was done to see correlation of ferritin with transient elastography and duration of HCV.

Results

Over all 120 patients fulfilling the selection criteria were selected after informed consent. These included 68 (56.7%) male & 52 (43.3%) female. Significant differences in ferritin levels by Fibrosis stages were observed by ANOVA (df = 3; F =12.768; p = <0.001). Serum ferritin showed linear pattern across Fibrosis stages (F = 33.948; p = <0.001). Regression analysis of ferritin and duration of HCV showed significant impact on TE scores (r² = 0.317).

Conclusions

There is significant correlation between serum ferritin and duration of HCV with TE scores.

Thyroid Disorders in Homozygous β-Thalassemia: Current Knowledge, Emerging Issues and Open Problems

Changes in thyroid function and thyroid function tests occur in patients with β-thalassemia major (TM). The frequency of hypothyroidism in TM patients ranges from 4% to 29 % in different reports. The wide variation has been attributed to several factors such as patients’ genotype, age, ethnic heterogeneity, treatment protocols of transfusions and chelation, and varying compliance to treatment. Hypothyroidism is the result of primary gland failure or insufficient thyroid gland stimulation by the hypothalamus or pituitary gland. The main laboratory parameters of thyroid function are the assessments of serum thyroid-stimulating hor-mone (TSH) and serum free thyroxine (FT4). It is of primary importance to interpret these measurements within the context of the laboratory-specific normative range for each test. An elevated serum TSH level with a standard range of serum FT4 level is consistent with subclinical hypothyroidism. A low serum FT4 level with a low, or inappropriately normal, serum TSH level is consistent with secondary hypothyroidism. Doctors caring for TM patients most commonly encounter subjects with subclinical primary hypothyroidism in the second decade of life. Several aspects remain to be elucidated as the frequency of thyroid cancer and the possible existence of a relationship between thyroid dysfunction, on one hand, cardiovascular diseases, components of metabolic syndrome (insulin resistance) and hypercoagulable state, on the other hand. Further studies are needed to explain these emerging issues. Following a brief description of thyroid hormone regulation, production and actions, this article is conceptually divided into two parts; the first reports the spectrum of thyroid disease occurring in patients with TM, and the second part focuses on the emerging issues and the open problems in TM patients with thyroid disorders.

Predicting factors for liver iron overload at the first magnetic resonance in children with thalassaemia major

BACKGROUND

Transfusion dependency determines iron overload in thalassaemia major, with devastating complications. Significant liver iron overload has been observed from early childhood and we aimed to evaluate factors that could predict liver iron overload at the first magnetic resonance imaging (MRI).

MATERIALS AND METHODS

All transfusion-dependent children who underwent MRI to assess iron overload were retrospectively studied. Age, weight, height, blood requirement, chelation drug and dosage, serum ferritin and liver enzymes were evaluated at three specific steps: start of transfusion regimen, start of chelation therapy, and first MRI.

RESULTS

Among 198 patients, 25 children met inclusion criteria. No differences were detected in all the assessed parameters at start of transfusion regimen and chelation therapy (p>0.05) between patients with good iron balance (liver iron concentration [LIC] <7 mg Fe/g dry weight [dw]) and liver iron overload (LIC >7). At the first MRI, patients with iron overload had significantly higher serum ferritin (3,080.3±1,078.5 vs 1,672.0±705.3 ng/mL; p<0.01) while patients with good iron control maintained a stable ferritin value from the start of chelation therapy but showed significantly lower height Z-score (-1.48±1.02 vs -0.36±1.55; p=0.04). Serum ferritin >1,770 ng/mL was detected as the best threshold for predicting liver iron overload at the first MRI (p=0.0003).

CONCLUSION

In order to prevent liver iron overload at the first MRI, children should maintain a stable level of serum ferritin below 1,770 from the start of chelation therapy. However, strict monitoring of growth is mandatory.