Maddalena Casale

Clinical and laboratory features of 103 patients from 42 Italian families with inherited thrombocytopenia derived from the monoallelic Ala156Val mutation of GPIbα (Bolzano mutation)

Background Bernard-Soulier syndrome is a very rare form of inherited thrombocytopenia that derives from mutations in GPIbα, GPIbβ, or GPIX and is typically inherited as a recessive disease. However, some years ago it was shown that the monoallelic c.515C>T transition in the GPIBA gene (Bolzano mutation) was responsible for macrothrombocytopenia in a few Italian patients. Design and Methods Over the past 10 years, we have searched for the Bolzano mutation in all subjects referred to our institutions because of an autosomal, dominant form of thrombocytopenia of unknown origin. Results We identified 42 new Italian families (103 cases) with a thrombocytopenia induced by monoallelic Bolzano mutation. Analyses of the geographic origin of affected pedigrees and haplotypes indicated that this mutation originated in southern Italy. Although the clinical expression was variable, patients with this mutation typically had a mild form of Bernard-Soulier syndrome with mild thrombocytopenia and bleeding tendency. The most indicative laboratory findings were enlarged platelets and reduced GPIb/IX/V platelet expression; in vitro platelet aggregation was normal in nearly all of the cases. Conclusions Our study indicates that monoallelic Bolzano mutation is the most frequent cause of inherited thrombocytopenia in Italy, affecting 20% of patients recruited at our institutions during the last 10 years. Because many people from southern Italy have emigrated during the last century, this mutation may have spread to other countries.

Endocrine function and bone disease during long-term chelation therapy with deferasirox in patients with β-thalassemia major

Iron overload in β‐thalassemia major (TM) typically results in iron‐induced cardiomyopathy, liver disease, and endocrine complications. We examined the incidence and progression of endocrine disorders (hypothyroidism, diabetes, hypoparathyroidism, hypogonadism), growth and pubertal delay, and bone metabolism disease during long‐term deferasirox chelation therapy in a real clinical practice setting. We report a multicenter retrospective cohort study of 86 transfusion‐dependent patients with TM treated with once daily deferasirox for a median duration of 6.5 years, up to 10 years. No deaths or new cases of hypothyroidism or diabetes occurred. The incidence of new endocrine complications was 7% (P = 0.338, for change of prevalence from baseline to end of study) and included hypogonadism (n = 5) and hypoparathyroidism (n = 1). Among patients with hypothyroidism or diabetes at baseline, no significant change in thyroid parameters or insulin requirements were observed, respectively. Mean lumbar spine bone mineral density increased significantly (P < 0.001) and the number of patients with lumbar spine osteoporosis significantly decreased (P = 0.022) irrespective of bisphosphonate therapy, hormonal replacement therapy, and calcium or vitamin D supplementation. There were no significant differences in the number of pediatric patients below the 5th centile for height between baseline and study completion. Six pregnancies occurred successfully, and four of them were spontaneous without ovarian stimulation. This is the first study evaluating endocrine function during the newest oral chelation therapy with deferasirox. A low rate of new endocrine disorders and a stabilization of those pre‐exisisting was observed in a real clinical practice setting. Am. J. Hematol. 89:1102–1106, 2014.

Splenectomy for hereditary spherocytosis: complete, partial or not at all?

Hereditary spherocytosis (HS) is an hematologic disorder, common in the Northern European population, which is characterized by hemolytic anemia and splenomegaly. The pathophysiological bedrock of HS consists of the retention and damage of abnormal red cells, caused by an intrinsic erythrocyte membrane defect. Hemolysis within the spleen is the main detrminant of erythrocyte destruction in patients with HS. Splenectomy removes the primary ‘graveyard’ for spherocytes and, thus, eliminates anemia and hyperbilirubinemia and lowers the high reticulocyte number to nearly normal levels. Spleen removal is an effective therapeutic option but it is not without risks. The incidence and public health impact of spleen surgery in children with HS is substantial. Unfortunately, splenectomy is sometimes recommended erroneously for young children who have a mild clinical phenotype or is performed without relying on careful assessment of the risks and benefits. This article aims to present criticism and address controversy about HS management. Unclear and still controversial issues are tackled according to the author’s personal viewpoint, because strong evidence in different aspects of HS management is lacking.

Long-term treatment with deferiprone enhances left ventricular ejection function when compared to deferoxamine in patients with thalassemia major.

Transfusion and iron chelation treatment have significantly reduced morbidity and improved survival of patients with thalassemia major. However, cardiac disease continues to be the most common cause of death. We report the left-ventricular ejection fraction, determined by echocardiography, in one hundred sixty-eight patients with thalassemia major followed for at least 5years who received continuous monotherapy with deferoxamine (N=108) or deferiprone (N=60). The statistical analysis, using the generalized estimating equations model, indicated that the group treated with deferiprone had a significantly better left-ventricular ejection fraction than did those treated with deferoxamine (coefficient 0.97; 95% CI 0.37; 1.6, p=0.002). The heart may be particularly sensitive to iron-induced mitochondrial damage because of the large number of mitochondria and its low level of antioxidants. Deferiprone, because of its lower molecular weight, might cross into heart mitochondria more efficiently, improving their activity and, thereby, myocardial cell function. Our findings indicate that the long-term administration of deferiprone significantly enhances left-ventricular function over time in comparison with deferoxamine treatment. However, because of limitations related to the design of this study, these findings should be confirmed in a prospective, randomized clinical trial.

Congenital Dyserythropoietic Anemia Type II: molecular analysis and expression of the SEC23B Gene

BackgroundCongenital dyserythropoietic anemia type II (CDAII), the most common form of CDA, is an autosomal recessive condition. CDAII diagnosis is based on invasive, expensive, and time consuming tests that are available only in specialized laboratories. The recent identification of SEC23B mutations as the cause of CDAII opens new possibilities for the molecular diagnosis of the disease. The aim of this study was to characterize molecular genomic SEC23B defects in 16 unrelated patients affected by CDAII and correlate the identified genetic alterations with SEC23B transcript and protein levels in erythroid precursors.MethodsSEC23B was sequenced in 16 patients, their relatives and 100 control participants. SEC23B transcript level were studied by quantitative PCR (qPCR) in peripheral erythroid precursors and lymphocytes from the patients and healthy control participants. Sec23B protein content was analyzed by immunoblotting in samples of erythroblast cells from CDAII patients and healthy controls.ResultsAll of the investigated cases carried SEC23B mutations on both alleles, with the exception of two patients in which a single heterozygous mutation was found. We identified 15 different SEC23B mutations, of which four represent novel mutations: p.Gln214Stop, p.Thr485Ala, p.Val637Gly, and p.Ser727Phe. The CDAII patients exhibited a 40-60% decrease of SEC23B mRNA levels in erythroid precursors when compared with the corresponding cell type from healthy participants. The largest decrease was observed in compound heterozygote patients with missense/nonsense mutations. In three patients, Sec23B protein levels were evaluated in erythroid precursors and found to be strictly correlated with the reduction observed at the transcript level. We also demonstrate that Sec23B mRNA expression levels in lymphocytes and erythroblasts are similar.ConclusionsIn this study, we identified four novel SEC23B mutations associated with CDAII disease. We also demonstrate that the genetic alteration results in a significant decrease of SEC23B transcript in erythroid precursors. Similar down-regulation was observed in peripheral lymphocytes, suggesting that the use of these cells might be sufficient in the identification of Sec23B gene alterations. Finally, we demonstrate that decreased Sec23B protein levels in erythroid precursors correlate with down-regulation of the SEC23B mRNA transcript.

Multiparametric Cardiac Magnetic Resonance Survey in Children With Thalassemia Major: A Multicenter Study.

Background—Cardiovascular magnetic resonance (CMR) plays a key role in the management of thalassemia major patients, but few data are available in pediatric population. This study aims at a retrospective multiparametric CMR assessment of myocardial iron overload, function, and fibrosis in a cohort of pediatric thalassemia major patients. Methods and Results—We studied 107 pediatric thalassemia major patients (61 boys, median age 14.4 years). Myocardial and liver iron overload were measured by T2* multiecho technique. Atrial dimensions and biventricular function were quantified by cine images. Late gadolinium enhancement images were acquired to detect myocardial fibrosis. All scans were performed without sedation. The 21.4% of the patients showed a significant myocardial iron overload correlated with lower compliance to chelation therapy (P<0.013). Serum ferritin ≥2000 ng/mL and liver iron concentration ≥14 mg/g/dw were detected as the best threshold for predicting cardiac iron overload (P=0.001 and P<0.0001, respectively). A homogeneous pattern of myocardial iron overload was associated with a negative cardiac remodeling and significant higher liver iron concentration (P<0.0001). Myocardial fibrosis by late gadolinium enhancement was detected in 15.8% of the patients (youngest children 13 years old). It was correlated with significant lower heart T2* values (P=0.022) and negative cardiac remodeling indexes. A pathological magnetic resonance imaging liver iron concentration was found in the 77.6% of the patients. Conclusions—Cardiac damage detectable by a multiparametric CMR approach can occur early in thalassemia major patients. So, the first T2* CMR assessment should be performed as early as feasible without sedation to tailor the chelation treatment. Conversely, late gadolinium enhancement CMR should be postponed in the teenager age.

Congenital erythrocytosis associated with gain-of-function HIF2A gene mutations and erythropoietin levels in the normal range

Hypoxia-inducible factor 2α (HIF-2α) plays a pivotal role in the balancing of oxygen requirements throughout the body. The protein is a transcription factor that modulates the expression of a wide array of genes and, in turn, controls several key processes including energy metabolism, erythropoiesis and angiogenesis. We describe here the identification of two cases of familial erythrocytosis associated with heterozygous HIF2A missense mutations, namely Ile533Val and Gly537Arg. Ile533Val is a novel mutation and represents the genetic HIF2A change nearest to Pro-531, the primary hydroxyl acceptor residue, so far identified. The Gly537Arg missense mutation has already been described in familial erythrocytosis. However, our patient is the only described case of a de novo HIF2A mutation associated with the development of congenital polycythemia. Functional in vivo studies, based on exogenous expression of hybrid HIF-2α transcription factors, indicated that these genetic alterations lead to the stabilization of HIF-2α protein. All the identified polycythemic subjects with HIF2A mutations show serum erythropoietin in the normal range, independently of the hematocrit values and phlebotomy frequency. The erythroid precursors obtained from the peripheral blood of patients showed an altered phenotype, including an increased rate of growth and a modified expression of some HIF-2α target genes. These results suggest the novel proposal that polycythemia observed in subjects with HIF2A mutations might also be due to primary changes in hematopoietic cells and not only secondary to increased erythropoietin levels.

Effect of splenectomy on iron balance in patients with β-thalassemia major: a long-term follow-up

A retrospective study was performed to explore the effect of splenectomy on iron balance in thalassemia major (TM).

HNF-1β mutation affects PKD2 and SOCS3 expression causing renal cysts and diabetes in MODY5 kindred.

BACKGROUND Maturity onset diabetes of young (MODY) type 5 is a form of non-insulin-dependent diabetes mellitus associated with renal cysts. It is an autosomal dominant disorder caused by mutations in the gene encoding hepatocyte nuclear factor-1β (HNF-1β). METHODS We performed molecular screening of HNF-1β in a 13-year-old patient and his affected father, and analyzed polycystic kidney disease 2 (PKD2) gene and suppressor of cytokine signaling 3 (SOCS3) expression in lymphoblastoid cell lines and lymphocytes from both patients. RESULTS We found a novel HNF-1β frameshift mutation (c.C1304del) that results in a truncated protein (p.I434IfsX1). The genetic change is localized in the transactivated protein domain. CONCLUSIONS We demonstrated that this novel HNF-1β mutation strongly influences the expression of both PKD2, responsible for the formation of the renal cysts, and SOCS3, which is associated with early diabetes onset.

Nephrolithiasis in patients exposed to deferasirox and desferioxamine: probably an age-linked event with different effects on some renal parameters

Dear Editor, We refer this letter to the manuscript by Efthimia et al. [1] in which they recently reported that in thalassemia major (TM) patients, the start of deferasirox (DFX) has been associated with increased risk of developing nephrolithiasis. However, in that series, several patients were also cotreated with calcium and vitamin D supplements, and the authors correctly hypothesized that it could have facilitated the renal calculi formation. Nevertheless, that clinical observation was not easy to evaluate by the fact that it was not a population-based case– control study and the definition of the population and the duration of patient exposure to DFX treatment were not reported; furthermore, the assessment of new cases was made only through the detection of renal colic. We reviewed the charts and radiological studies of our patients with TM to retrospectively evaluate the incidence of nephrolithiasis in those treated with DFX and in a matched control population treated with desferioxamine (DFO). The presence or the absence of nephrolithiasis had to be assessed by abdominal ultrasonography. To further analyze data, total therapy exposure and the incidence of nephrolithiasis adjusted to 100 years of patient exposure were calculated for each treatment. To make series comparable, data from patients under DFO treatment were collected since January 2010. The study was approved by the Ethics Committee of the Cardarelli Hospital, Napoli. Table 1 shows demographics and clinical characteristics of patients divided in those exposed to DFX and to DFO at baseline and at the end of drug exposure (October 2012). At baseline, both populations were comparable for previous chelation history, for the percentage of patients splenectomized and using calcium and vitaminD, for the mean creatinine level and GFR value, and for the prevalence of renal calculi [2], but patients treated with DFX tended to be younger and to have lower level of uric acid. Patients already affected by renal calculi were in average 40 years old and frequently splenectomized, but they did not use vitamin D and calcium supplementation more frequently than those without stones and were not always symptomatic; however, in those under DFO treatment, a decrease in GFR was observed following drug exposure. Comparing basal and final values in a population without stones, an increase in creatinine level and a decrease in GFR were observed in the DFX group. We observed eight (5.26/100 patients/year ) and five (4.76/100 patients/year) new cases of renal stones in patients treated with DFX and DFO, respectively, and the O.R. for developing nephrolithiasis under DFX was 1.17 , p=0.79 (data not shown). Interestingly, among stone formers following DFX treatment, a significant decrease in uric acid level without a decrease in renal function parameters was observed. Estimates of the incidence of renal stones in TM patients are lacking [3]. In spite of this, a sustained rate of renal stone formation under DFX treatment was confirmed; these data highlight the presence of an asymptomatic disease that may have contributed to its underestimation in the DFO group in Efthimia’s series [1]. In our series, renal stone formation appears to involve mainly patients older than 30 while the P. Ricchi :M. Ammirabile : S. Costantini :A. Spasiano : P. Cinque :M. Casale :A. Filosa : L. Prossomariti UOSD Centro delle Microcitemie “A. Mastrobuoni”, AORN A. Cardarelli, Naples, Italy