Celocentesis for Early Prenatal Diagnosis in Couples at-Risk for ß-Thalassemia and Sicilian (δß)0-Thalassemia.

The procedures commonly used for prenatal diagnosis (PND) of thalassemia are villocentesis or amniocentesis, respectively, at the 11th and 16th weeks of gestation. Their main limitation is essentially due to the late gestation week in which diagnosis is performed. The celomic cavity is accessible between the 7th and 9th weeks of gestation and it has been demonstrated that it contains embryonic erythroid precursor cells as a source of fetal DNA for earlier invasive PND of thalassemia and other monogenic diseases. In this study, we report the use of celomatic fluids obtained from nine women with high-risk pregnancies for Sicilian (δß)0-thalassemia [(δß)0-thal] deletion (NG_000007.3: g.64336_77738del13403) and ß-thalassemia (ß-thal). Fetal cells were isolated by a micromanipulator, and nested polymerase chain reaction (PCR) and short tandem repeats (STRs) analysis were performed. Prenatal diagnosis was successfully performed in all examined cases. One fetus was a compound heterozygote for (δß)0- and ß-thal, three fetuses were found to be carriers of ß-thal, four fetuses carriers of a Sicilian 뫧 deletion, and one fetus without parental mutations. Accidentally, a rare case of paternal triploidy was observed. The genotypic analysis, carried out both by amniocentesis and on abortive tissue or after birth, showed concordance with results obtained on fetal celomic DNA. Our results unequivocally show that fetal DNA can be obtained by nucleated fetal cells present in the celomatic fluid and demonstrate, for the first time, that PND of Sicilian (δß)0-thal and ß-thal is feasible at an earlier time in pregnancy than other procedures.

Very early prenatal diagnosis of Cockayne's syndrome by coelocentesis.

Cockayne's syndrome (CS) is a rare autosomal recessive multisystem disease characterised by early severe progression of symptoms. This study reports the feasibility of earlier prenatal diagnosis of CS by coelocentesis at 8 weeks of gestation respect to amniocentesis or villocentesis. Three couples at risk for CS asked to perform prenatal diagnosis by coelocentesis. Coelomic fluid was aspired from coelomic cavity in four singleton pregnancy at 8 weeks of gestation and 40 foetal cells were recovered by micromanipulator. Maternal DNA contamination was evaluated by quantitative fluorescent PCR (QF-PCR) and target regions of foetal DNA containing parental mutations of ERCC6 gene were amplified and sequenced. In all these cases, molecular analysis was possible. One foetus resulted affected of CS and the diagnosis was confirmed on placental tissue after voluntary abortion. In three cases, foetuses resulted carrier of a parental mutation and the results were confirmed after the birth. This study suggests that reliable prenatal diagnosis of CS could be performed using foetal cells present in coelomatic fluid in earlier pregnancy. Coelocentesis could be applied in prenatal diagnosis of CSs as well as for other monogenic diseases, at very early stage of pregnancy, if parental mutations are already known.Impact StatementWhat is already know on this subject? Previous studies utilising coelocentesis for prenatal determination of foetal sex reported variable success ranging from 58% to 95%, because of low total DNA content and presence of maternal cell contamination. This procedure has never been reported for early prenatal diagnosis at 8 weeks of gestation for rare genetically transmitted diseases such as Cockayne's syndrome.What do the results of this study add? This study demonstrates that coelomic fluid sampling combined with well-standardised laboratory procedures can be applied for prenatal diagnosis at eight weeks of gestation for any rare monogenic disease if molecular defects are known.What are the implications of these findings for clinical practice and/or further research? The findings of this study in at risk couples for monogenic diseases investigated by coelocentesis demonstrate that embryo-foetal cell selection from CF allows reliable and early prenatal diagnosis of diseases. This technique is attractive to parents because it provides prenatal diagnosis of genetic disease at least 4 weeks earlier than what can be achieved by the traditional procedures reducing anxiety of parents and provides the option for medical termination of affected cases at 8-10 weeks' gestation, which is less traumatic and safer than second-trimester surgical termination. Further research concerns the possibility to obtain foetal karyotype at eight weeks of gestation and the possibility of intrauterine corrective therapy.

Double Heterozygosity for Hb Durham-N.C. (HBB: c.344T>C) [ß114(G16)Leu→Pro] and the IVS-I-110 (HBB: c.93-21G>A) Causing a Severe ß-Thalassemia Phenotype.

The evaluation of a 10-month-old girl of Sicilian origin with a clinical phenotype of severe thalassemia led to the identification of two ß-globin gene defects, a ß-thalassemia (ß-thal), mutation at IVS-I-110 (HBB: c.93-21G>A) and a variant hemoglobin (Hb) mutation at codon 114 (HBB: c.344T>C) on the other allele, reported as Hb Durham-N.C. (also known as Hb Brescia) [ß114(G16)Leu→Pro] in the HbVar database. A very low Hb level (Hb 3.5 g/dL), microcytosis [mean corpuscular volume (MCV) 63.2 fL] and hypocromia [mean corpuscular Hb (MCH) 19.6 pg], increased red blood cell (RBC) distribution width (RDW) (36.0%), higher reticulocytes (6.2%), anisocytosis, poikilocytosis, hypocromia, basophilic stippling and inclusion body formation, were present in the affected subject. Analysis of other family components showed the presence of HBB: c.93-21G>A defect in the mother and in her brother, while Hb Durham-N.C. was absent in all other relatives, thus, this mutation has arisen as a de novo defect. This is the first case described as a severe thalassemic phenotype in a compound heterozygote carrier of this unstable Hb and a common ß-thalassemic allele. The important information gained from this case is that a rare dominant or recessive mutation may arise in every individual, even if this is a very rare event.

Longitudinal changes in LIC and other parameters in patients receiving different chelation regimens: Data from LICNET.

OBJECTIVES: The liver remains the primary site of iron storage, with liver iron concentration (LIC) being a strong surrogate of total body iron. MRI-R2 can accurately measure LIC. The LICNET (Liver Iron Cutino Network) was established to diagnostics of liver iron overload by MRI-R2 subjects with hemochromatosis in hematological disorders. The aims of the study were to look at variation in LIC measurements during time across different chelation regimens. METHODS: This was a cross-sectional study of 130 patients attending 9 Italian centers participating in the LICNET. LIC comparisons over time (T0 and T1 ) were made using t test and/or Wilcoxon test. RESULTS: LIC significantly decreased from MRI1 to MRI2 although at high variance (median change -0.8 mg Fe/g dw, range: -29.0 to 33.0; P = .011) and 7.7% of patients shifted from LIC values of high risk (>15 mg Fe/g dw) to an intermediate-risk category (7-15 mg Fe/g dw). Median change in LIC and correlation with serum ferritin levels (SF), during different chelation regimens, is reported. CONCLUSIONS: These findings suggest as longitudinal variation in the LIC is possible, across all chelation regimens. It confirms as SF levels not always can be used for estimating changes in LIC.

Phenotypic Evaluation of a Novel Nucleotide Substitution (HBD: c.442T>C) on the δ-Globin Gene.

HBD: c.442T>C is a new mutation at the stop codon (TGA>CGA) of the δ-globin gene, which produces a new codon for arginine. This substitution causes a 51 nucleotides longer open reading frame determining the synthesis of a potential larger δ subunit, which is a probable target of mechanisms for the degradation of aberrant proteins as well as the defective synthesized mRNA molecules, and may also be rapidly degraded by a variety of RNA surveillance pathways. We identified this molecular defect in four patients: three women with a reduced HbA2 level and a 37-year-old male showing the typical phenotype of an α-thalassemia (α-thal) carrier with reduced values of red cell indices and normal HbA2 level (2.5%). The mutation on the δ-globin gene was found to have been coinherited with a ß-globin gene defect leading to a normalized HbA2 level. These data support the necessity of investigating these cases at a molecular level, particularly if the partner is also a ß-thalassemia (ß-thal) carrier. The present data emphasizes the importance of a careful evaluation of correlation between genotypes resulting from DNA analysis and phenotypes, especially in cases of atypical hematological parameters, in order to carry out an adequate diagnostic process finalized to appropriate genetic counseling.

HBB: c.316-125A>G and HBB: c.316-42delC: Phenotypic Evaluations of Two Rare Changes in the Second Intron of the HBB Gene.

We report two very rare changes in the second intron of the HBB gene, a substitution at nucleotide (nt) 726 [IVS-II-726 (A>G) (ß+), NM_000518, HBB: c.316-125A>G] and a deletion of a cytosine at nt 809 [IVS-II-809 (-C) (ß), NM_000518, HBB: c.316-42delC] identified during the screening program for hemoglobinopathies in the resident Sicilian population. The purpose of this study was to evaluate the clinical implication of these rare changes, particularly in coinheritance with known mutations in the globin clusters, in order to conduct an appropriate genetic counseling for at-risk couples. Molecular analysis detected the first rare nt substitution in two cases in simple heterozygosity and in two cases in association with other known mutations on globin genes, while the deletion was identified in a pregnant woman, carrier of ß-thal, and in her fetus at prenatal diagnosis (PND) for hemoglobinopathies. The present study emphasizes the importance of sharing the observed changes in the globin gene cluster, especially in the case of new or rare undefined mutations, in order to facilitate the determination of their phenotypic expression and possible interactions with known molecular defects.

Real-life experience with liver iron concentration R2 MRI measurement in patients with hemoglobinopathies: baseline data from LICNET.

BACKGROUND: Real-life data on the use of R2 MRI for the assessment of liver iron concentration (LIC) remain limited. METHODS: We conducted a cross-sectional analysis on 363 patients (mean age 35.6 yr, 44.1% men) with hemoglobinopathies (204 ß-thalassemia major [TM], 102 ß-thalassemia intermedia [TI], and 57 sickle cell disease [SCD]) that were evaluated with R2 MRI as part of LICNET, an MRI network of 13 Italian treatment centers. RESULTS: The mean LIC was 7.8 mg/g (median: 4.0), with high LIC (>7 mg/g) noted in both transfused (TM, TI 37%; SCD 38%) and non-transfused (TI 20%) patients. Ferritin levels correlated with LIC in both transfused (TM, TI, SCD) and non-transfused (TI) patients (P < 0.001), although lower values predicted high LIC in non-transfused patients (1900 vs. 650 ng/mL in TM vs. non-transfused TI). A correlation between LIC and ALT levels was only noted in HCV-negative patients (rs = 0.316, P < 0.001). The proportion of patients with high LIC was significantly different between iron chelators used (P = 0.023), with the lowest proportion in deferasirox (30%) and highest in deferiprone (53%)-treated patients. CONCLUSIONS: High LIC values persist in subgroups of patients with hemoglobinopathy, warranting closer monitoring and management optimization, even for non-transfused patients with relatively low ferritin levels.

Coinheritance of a Rare Nucleotide Substitution on the ß-Globin Gene and Other Known Mutations in the Globin Clusters: Management in Genetic Counseling.

A large number of methods for DNA analysis are available to identify defects in globin genes associated with hemoglobin (Hb) disorders. In this study, we report a rare nucleotide (nt) substitution on the ß-globin gene, nt 781 in the second intron [IVS-II-781 (C > G); HBB: c.316-70C > G], identified in four patients. This nt substitution was previously described only as a personal communication to the HbVar database and indicated as a ß(0) or ß(+) mutation. The purpose of this study was to evaluate the clinical implication of this nt change, particularly when coinherited with severe ß-thalassemia (ß-thal), in order to be able to conduct appropriate genetic counseling. Genetic studies were performed on two subjects, one carried Hb S [ß6(A3)Glu→Val; HBB: c.20A > T], and the other carried IVS-I-110 (G > A) (HBB: c.93-21G > A). All these subjects showed this new ß nt substitution in association with Hb A2' (or Hb B2) [δ16(A13)Gly→Arg; HBD: c.49G > C]. Another 16 samples, carrying the same δ variant as the probands, were processed by ß-globin gene sequencing in order to better understand the correlation between this Hb variant and the rare nt substitution reported in this study. The present investigation emphasizes the importance of sharing the observed nt changes in the globin gene cluster, especially in the case of new or rare undefined mutations, in order to facilitate the determination of their phenotypic expression, the possible interactions with known molecular defects and to formulate appropriate genetic counseling for at-risk couples.

Hb San Cataldo [ß144(HC1)Lys→Thr; HBB: C.434A > C]: A New Hemoglobin Variant with Increased Affinity for Oxygen.

A 59-year-old Italian woman came to our center for revaluation of a previous diagnosis of polycythemia vera. The patient presented with a lifelong history of polycythemia, no increase in white blood cells (WBCs) and platelets, and a negative bone marrow biopsy. Analysis of hemoglobin (Hb) fractions showed an abnormal fast moving Hb component. We aimed to determine if this variant was the cause of polycythemia in this patient. A complete blood count (CBC) was performed by an automated cell counter and Hb fractions were determined by high performance liquid chromatography (HPLC). Standard stability tests and oxygen affinity evaluation were also performed. Genomic DNA was extracted from peripheral blood leukocytes using the phenol chloroform method and the entire ß-globin gene was analyzed by direct sequencing. At the hematological level, no anemia or hemolysis was observed but an abnormal Hb fraction was detected using cation exchange HPLC. Molecular analysis of the ß-globin gene showed heterozygosity for an AAG > ACG substitution at codon 144, resulting in a Lys→Thr amino acid replacement. We demonstrated that this is a new Hb variant with increased oxygen affinity. Its altered physiology is caused by the reduction of 2,3-diphosphoglycerate (2,3-DPG) effects, due to an amino acid substitution in the central pocket near the C-terminal of the ß chain. We called this new variant Hb San Cataldo for the native city of proband.

Co-inheritance of the rare ß hemoglobin variants Hb Yaounde, Hb Görwihl and Hb City of Hope with other alterations in globin genes: impact in genetic counseling.

PURPOSE: Nearly 1183 different molecular defects of the globin genes leading to hemoglobin variants have been identified (http://globin.bx.psu.edu) over the past decades. The purpose of this study was to report three cases, never described in the literature, of co-inheritance of three ß hemoglobin variants with other alterations in globin genes and to evaluate the clinical significance to conduct an appropriate genetic counseling. PATIENTS AND METHODS: We report the molecular study performed in three probands and their families, sampling during the screening program conducted at the Laboratory for Molecular Prenatal Diagnosis of Hemoglobinopathies at Villa Sofia-Cervello Hospital in Palermo, Italy. RESULTS: This work allowed us to describe the co-inheritance of three rare ß hemoglobin variants with other alterations in globin genes: the ß hemoglobin variant Hb Yaounde [ß134(H12)Val>Ala], found for the first time in combination with ααα(anti3.7) arrangement, and the ß hemoglobin variants Hb Görwihl [ß5(A2)Pro>Ala] and Hb City of Hope [ß69(E13)Gly>Ser], found both in association with ß(0) -thalassemia. CONCLUSION: The present work emphasizes the importance of a careful evaluation of the hematological data, especially in cases of atypical hematological parameters, to carry out an adequate and complete molecular study and to formulate an appropriate genetic counseling for couples at risk.

Identification of three new nucleotide substitutions in the ß-globin gene: laboratoristic approach and impact on genetic counselling for beta-thalassaemia.

PURPOSE: Over the past two decades, a wide range of available methods for DNA analysis have allowed us to identify defects in globin genes associated with haemoglobin disorders and to correlate specific mutations with phenotypic expression. The purpose of this study was to evaluate the nature of three new nucleotide changes, mutation or single nucleotide polymorphism, found in the beta-globin gene, to conduct an appropriate genetic counselling. PATIENTS AND METHODS: We report the molecular study performed in three probands and their families, sampling during the screening programme conducted at the Laboratory for Molecular Prenatal Diagnosis of Hemoglobinopathies at Villa Sofia-Cervello Hospital in Palermo, Italy. RESULTS: This work allowed us to report three new nucleotide substitutions of the ß-globin gene: a substitution of the nucleotide 16 in the CAP site area (HBB: c.-35 A>G), a substitution of the nucleotide 478 in the second intron (HBB: c.316-373) in association with ß-haemoglobin variant Hb G Copenhagen (HBB:c.142G>A) and a substitution of the nucleotide 1656 within the 3' UTR (HBB: c.*+182 G>A) in association with the 1393-bp deletion (NG_000007.3:g.70060_71452del1393). CONCLUSION: The present work emphasizes the importance of reporting the observed nucleotide changes to the Haemoglobin Variant Database, especially in the case of new or rare undefined mutations, to facilitate the determination of their phenotypic expression and the possible interactions with known molecular defects and to formulate an appropriate genetic counselling for couples at risk.

Prenatal Diagnosis of Cystic Fibrosis by Celocentesis.

Celocentesis is a new sampling tool for prenatal diagnosis available from 7 weeks in case of couples at risk for genetic diseases. In this study, we reported the feasibility of earlier prenatal diagnosis by celocentesis in four cases of cystic fibrosis and one case of cystic fibrosis and ß-thalassemia co-inherited in the same fetus. Celomic fluids were aspired from the celomic cavity between 8+2 and 9+3 weeks of gestation and fetal cells were picked up by micromanipulator. Maternal DNA contamination was tested and target regions of fetal DNA containing parental pathogenetic variants of CFTR and HBB genes were amplified and sequenced. Four of the five fetuses resulted as being affected by cystic fibrosis and, in all cases, the women decided to interrupt the pregnancy. In the other case, the fetus presented a healthy carrier of cystic fibrosis. The results were confirmed in three cases on placental tissue. In one case, no abortive tissue was obtained. In the last case, the woman refused the prenatal diagnosis to confirm the celocentesis data; the pregnancy is ongoing without complications. This procedure provides prenatal diagnosis of monogenic diseases at least four weeks earlier than traditional procedures, reducing the anxiety of patients and providing the option for medical termination of the affected fetus at 8-10 weeks of gestation, which is less traumatic and safer than surgical termination in the second trimester.

Management of chronic viral hepatitis in patients with thalassemia: recommendations from an international panel.

Chelation therapy with new drugs prevents cardiac damage and improves the survival of thalassemia patients. Liver diseases have emerged as a critical clinical issue. Chronic liver diseases play an important role in the prognosis of thalassemia patients because of the high frequency of viral infections and important role of the liver in regulating iron metabolism. Accurate assessment of liver iron overload is required to tailor iron chelation therapy. The diagnosis of hepatitis B virus- or hepatitis C virus-related chronic hepatitis is required to detect patients who have a high risk of developing liver complications and who may benefit by antiviral therapy. Moreover, clinical management of chronic liver disease in thalassemia patients is a team management issue requiring a multidisciplinary approach. The purposes of this paper are to summarize the knowledge on the epidemiology and the risks of transmission of viral infections, to analyze invasive and noninvasive methods for the diagnosis of chronic liver disease, to report the knowledge on clinical course of chronic viral hepatitis, and to suggest the management of antiviral therapy in thalassemia patients with chronic hepatitis B or C virus or cirrhosis.

Early prenatal diagnosis of Hb Lepore Boston-Washington and ß-thalassemia on fetal celomatic DNA.

INTRODUCTION: Analysis of fetal DNA in at risk couples for thalassemia is performed from fetal trophoblast or amniotic fluid cells. Although these procedures are in common use, the main limitation is essentially due to the late gestation week in which diagnosis is performed. The celomic cavity develops around 4 weeks of pregnancy within the extraembryonic mesoderm and contains embryonic erythroid precursor cells as a source of fetal DNA that can be used to perform invasive prenatal diagnosis. METHODS: Celomatic fluids were obtained at 8 weeks of gestation in thirteen women with high-risk pregnancies. Twelve of these couples were at risk for Hb Lepore disease and ß-thalassemia and one couple represented a rare case in which both parents were carriers of Hb Lepore Boston-Washington. Fetal cells were isolated by micromanipulator and nested polymerase chain reactions were performed. RESULTS: The analysis was successfully performed in all examined cases. Two fetuses were found to have a compound heterozygosity for ß-thalassemia and Hb Lepore Boston-Washington, three fetuses were found to be carriers of ß-thalassemia, three fetuses of Hb Lepore, five were found without parental mutations. The genotypic analysis, carried out both by amniocentesis and on abortive tissue or after birth, showed concordance with results obtained on fetal celomic DNA. CONCLUSION: Our results unequivocally show that fetal DNA can be obtained by nucleated fetal cells present in celomatic fluid and demonstrate for the first time that prenatal diagnosis of ß-thalassemia and Hb Lepore may be feasible in an earlier time of pregnancy than other procedures.

Celomic Fluid: Laboratory Workflow for Prenatal Diagnosis of Monogenic Diseases.

BACKGROUND: Celomic fluid can be considered as an ultra-filtrate of maternal serum, containing a high protein concentration, urea, and many other molecules. It is an important transfer interface and a reservoir of nutrients for the embryo. Celomic fluid contains fetal cells that can be used for prenatal diagnosis of monogenic diseases in an earlier gestational period than villocentesis and amniocentesis. OBJECTIVE: The purpose of this study was to evaluate the characteristics of celomic fluid and to establish a workflow laboratory procedure for very early prenatal diagnosis of monogenic diseases. METHODS: Three hundred and eighty-five celomatic fluids were collected between the seventh and tenth week of gestation. We sampled 1 mL of celomic fluid in all cases. The embryo-fetal erythroid precursor cells were selected by the anti-CD71 microbead method or by a direct micromanipulator pick-up on the basis of their morphology. We amplified the extracted DNA using a nested polymerase chain reaction. Primers for short tandem repeat amplification were used to perform a quantitative fluorescent polymerase chain reaction evaluation to control maternal contamination. RESULTS: We observed maternal contamination in 95% of celomic fluids with a range between 5 and 100%. No fetal cells were observed in 0.78% of celomic fluids. The number of fetal cells ranged from a few units to several hundred. Isolation of embryo-fetal erythroblasts selected by the micromanipulator made diagnosis feasible in all cases. CONCLUSIONS: The selection of fetal cells by a micromanipulator and nested polymerase chain reaction analysis made celomatic fluid suitable for early prenatal diagnosis of monogenic disorders even in the presence of high maternal contamination and few fetal cells. The procedure reported in this study provides the opportunity for the use of celomic fluid sampled by celocentesis as an alternative to chorionic villi sampling and amniocentesis, to allow invasive prenatal diagnosis at a very early stage of pregnancy.

Incidental Detection of a Chromosomal Aberration by Array-CGH in an Early Prenatal Diagnosis for Monogenic Disease on Coelomic Fluid.

BACKGROUND: Turner syndrome is a rare genetic condition in which a female is partly or completely missing an X chromosome. Signs and symptoms vary among those affected. In fetuses that survive at birth and without congenital malformations, the prognosis is usually positive, but it has high lethality in utero, especially in the first trimester of pregnancy. METHODS: We report a case of monosomy X detected during a prenatal diagnosis for beta thalassemia on coelomic fluid (CF) at the VIII week of gestation. Beta globin gene analysis, whole genome amplification (WGA), quantitative fluorescent PCR and array comparative genomic hybridization (array-CGH) were performed on DNA extracted from CF. RESULTS: A monoallelic pattern of all Short Tandem Repeats mapped on the X chromosome was found and array-CGH performed on WGA from a few fetal erythroblasts confirmed monosomy X. CONCLUSION: This report underlines the importance of an early prenatal diagnosis and the countless potentialities of array-CGH that could make definition of molecular karyotype possible from a few fetal cells, unlike conventional cytogenetic techniques that require a greater cellular content. This is the first report of a molecular karyotype obtained from two cells selected by micromanipulation of CF and defined at such an early gestational age.

The genetic heterogeneity of ß-globin gene defects in Sicily reflects the historic population migrations of the island.

The aim of this study is to update the incidence and the distribution of the globin gene defects causing ß-thalassemia and abnormal hemoglobins in Sicily. The data derived from a total of 8875 beta-thalassemia alleles and 1330 variant hemoglobin chromosomes studied in Sicily from 1990 during a hemoglobinopathy control program. Fifty-four beta-globin gene defects were characterized, involving 30 different beta-thalassemia mutations and 24 variant hemoglobins. Eight of 30 ß-thalassemia defects accounted for 95.11% of examined alleles while other beta-globin gene defects were found at lower frequencies (<1%). A consistent number (24) of variant hemoglobins were identified of whom Hb S was the most represented (72.1%). Our data underline the heterogeneity of the beta-globin gene defects in the Sicily. The enormous progress in the technique for ß-globin gene analysis permitted to characterize 99.93% of mutated alleles and it has made a first trimester prenatal diagnosis program possible in our region in all cases with a great improvement in thalassemia management. The origin of the large spectrum of mutations is discussed taking in consideration the history of the island.

Iron chelation therapy in thalassemia major: a systematic review with meta-analyses of 1520 patients included on randomized clinical trials.

The effectiveness of deferoxamine (DFO), deferiprone (DFP), or deferasirox (DFX) in thalassemia major was assessed. Outcomes were reported as means±SD, mean differences with 95% CI, or standardized mean differences. Statistical heterogeneity was tested using χ2 (Q) and I2. Sources of bias and Grading of Recommendations Assessment, Development and Evaluation system (GRADE) were considered. Overall, 1520 patients were included. Only 7.4% of trials were free of bias. Overall measurements suggest low trial quality (GRADE). The meta-analysis suggests lower final liver iron concentrations during associated versus monotherapy treatment (p<0.0001), increases in serum ferritin levels during DFX 5, 10, and 20 mg/kg versus DFO-treated groups (p<0.00001, p<0.00001, and p=0.002, respectively), but no statistically significant difference during DFX 30 mg/kg versus DFO (p=0.70), no statistically significant variations in heart T2* signal during associated or sequential versus mono-therapy treatment (p=0.46 and p=0.14, respectively), increases in urinary iron excretion during associated or sequential versus monotherapy treatment (p=0.008 and p=0.02, respectively), and improved ejection fraction during associated or sequential versus monotherapy treatment (p=0.01 and p<0.00001, respectively). These findings do not support any specific chelation treatment. The literature shows risks of bias, and additional larger and longer trials are needed.

A critical review of non invasive procedures for the evaluation of body iron burden in thalassemia major patients.

It is evident that different non invasive methodologies have been implemented for the detection of organ specific iron burden in patients with thalassemia major. Among these MR relaxometry has the potential to become the method of choice for non-invasive, safe and accurate assessment of organ-specific iron load, although further theoretical research, along with studies monitoring wider age groups of patients, is needed. Moreover, the possibility of detecting organ-specific iron burden is relevant for tailoring specific chelation treatment in different patients or in the same patient during different periods of life. In fact, while heart organ-specific effect has been suggested by MR relaxometry for some chelation treatments, it is possible to suppose that another single chelator or association of other chelators may show different organ-specific effects. For these reasons, the future of our clinical research will be to understand, mainly by MR relaxometry, whether it would be possible to set up a tailored organ-specific chelation treatment, according to this supposed difference in organ efficacy of the current chelation therapies.