Thrombocytosis in children and adolescents-classification, diagnostic approach, and clinical management.

Secondary thrombocytosis is a frequent secondary finding in childhood infection and inflammation. Primary hereditary thrombocytosis may be caused by germline mutations within the genes encoding key regulators of thrombopoiesis, i.e., thrombopoietin (THPO) and its receptor c-MPL (MPL) or the receptor's effector kinase Januskinase2 (JAK2). Furthermore, somatic mutations in JAK2, MPL, and in the gene-encoding calreticulin (CALR) have been described to act as driver mutations within the so-called Philadelphia-negative myeloproliferative neoplasms (MPNs), namely essential thrombocythemia (ET), polycythemia vera (PV), and primary myelofibrosis (PMF). Increasing knowledge on the molecular mechanisms and on the clinical complications of these diseases is reflected by the WHO diagnostic criteria and European LeukemiaNet (ELN) recommendations on the management of adult MPN. However, data on childhood thrombocytosis are rare, and no consensus guidelines for pediatric thrombocytosis exist. Current literature has highlighted differences in the epidemiology and molecular pathogenesis of childhood thrombocytosis as compared to adults. Furthermore, age-dependent complications and pharmacological specificities suggest that recommendations tailored to the pediatric population are necessary in clinical practice. Here we summarize literature on classification, diagnostics, and clinical management of childhood thrombocytosis.

MR Imaging and Clinical Characteristics of Diffuse Glioneuronal Tumor with Oligodendroglioma-like Features and Nuclear Clusters.

BACKGROUND AND PURPOSE: Diffuse glioneuronal tumor with oligodendroglioma-like features and nuclear clusters (DGONC) is a new, molecularly defined glioneuronal CNS tumor type. The objective of the present study was to describe MR imaging and clinical characteristics of patients with DGONC. MATERIALS AND METHODS: Preoperative MR images of 9 patients with DGONC (median age at diagnosis, 9.9 years; range, 4.2-21.8 years) were reviewed. RESULTS: All tumors were located superficially in the frontal/temporal lobes and sharply delineated, displaying little mass effect. Near the circle of Willis, the tumors encompassed the arteries. All except one demonstrated characteristics of low-to-intermediate aggressiveness with high-to-intermediate T2WI and ADC signals and bone remodeling. Most tumors (n = 7) showed a homogeneous ground-glass aspect on T2-weighted and FLAIR images. On the basis of the original histopathologic diagnosis, 6 patients received postsurgical chemo-/radiotherapy, 2 were irradiated after surgery, and 1 patient underwent tumor resection only. At a median follow-up of 61 months (range, 10-154 months), 6 patients were alive in a first complete remission and 2 with stable disease 10 and 21 months after diagnosis. The only patient with progressive disease was lost to follow-up. Five-year overall and event-free survival was 100% and 86±13%, respectively. CONCLUSIONS: This case series presents radiomorphologic characteristics highly predictive of DGONC that contrast with the typical aspects of the original histopathologic diagnoses. This presentation underlines the definition of DGONC as a separate entity, from a clinical perspective. Complete resection may be favorable for long-term disease control in patients with DGONC. The efficacy of nonsurgical treatment modalities should be evaluated in larger series.

Hereditary hyperferritinemia cataract syndrome: clinical, genetic, and laboratory findings in 5 families.

BACKGROUND: The hereditary hyperferritinemia cataract syndrome (HHCS) is an autosomal dominant disorder characterized by high serum ferritin and early onset cataract. Mutations in the iron responsive element (IRE) within the 5' untranslated region of the L-ferritin (FTL) gene lead to constitutive L-ferritin synthesis resulting in hyperferritinemia. Bilateral cataract formation is caused by the intracellular accumulation of ferritin in the lens. PATIENTS: 4 children from unrelated families were referred for further exploration of hyperferritinemia which was detected during the diagnostic work-up of gastroenterological or hematological disorders. 1 patient was primarily referred for the investigation of bilateral cataract.Diagnostics included routine blood analysis, including complete blood count, iron status, liver and kidney parameters, a physical and an ophthalmological examination. Molecular genetic analysis of the FTL IRE was performed in 4 patients by PCR from genomic DNA and subsequent direct sequencing. RESULTS: All index patients presented with isolated hyperferritinemia without iron overload and had a positive family history for early onset cataract. Age at onset and disease severity varied between different families and among family members. Molecular genetic analysis revealed point mutations within the FTL IRE. CONCLUSION: In patients with hyperferritinemia but without any other sign of iron overload or inflammation HHCS should be considered to avoid complex and invasive procedures. Vice versa, in patients with familial inherited cataract the early serum ferritin measurement helps to avoid unnecessary diagnostics.

[Guidelines for diagnosis and treatment of secondary iron overload in patients with congenital anemia]. / S2-Leitlinie zur Diagnostik und Therapie der sekundären Eisenüberladung bei Patienten mit angeborenen Anämien.

In Germany and Central Europe, congenital disorders leading to secondary hemochromatosis are rare. The majority of these patients are treated in peripheral medical institutions. As a consequence, the experience of each institution in the treatment of secondary hemochromatosis in patients with congenital anemia is limited. Recent developments concerning new chelating agents, their combination for intensified chelation and new possibilities to diagnose and monitor iron overload have important consequences for the management of patients with secondary hemochromatosis and increase its complexity enormously. Therefore, the development of a guideline for rational and efficient diagnostics and treatment was necessary. The new guideline was developed within a formal consensus process and finally approved by a consensus conference with participants from both the pediatric and adult German hematology societies (GPOH and DGHO). Apart from general information and recommendations, the guideline contains 9 consensus statements on diagnostics (iron status, siderotic complications, chelator side-effects), the start of chelation, indications for intensified chelation, iron elimination in specific disorders, and iron elimination after stem cell transplantation. Here, these consensus statements are presented and discussed in detail. For the complete text of the guideline, please visit the AWMF homepage at http://www.leitlinien.net .

MRI-Based Liver Iron Content Determination at 3T in Regularly Transfused Patients by Signal Intensity Ratio Using an Alternative Analysis Approach Based on R2* Theory.

OBJECTIVES: To evaluate the feasibility of addressing liver iron content (LIC) in regularly transfused patients by MR imaging at 3 T based on the signal intensity ratio (SIR). An innovative data analysis approach was developed for this purpose. METHODS: 47 consecutive examinations of regularly transfused patients were included. In all cases, we expected high LIC levels. Patients were scanned with MRI at 3 T with multi-echo gradient echo sequences (GRE) at four different flip angles between 20° and 90° with echo times (TE) ranging from 0.9 to 9.8 ms. Spin-echo protocols were acquired to determine the LIC with a reference MRI method working at 1.5 T. 3 T GRE data were analyzed using the liver-to-muscle SIR. Since the method known for 1.5 T was not expected to be applicable for analyzing 3 T data, theoretic dependence of the SIR on the LIC was derived from the equation describing R2* signal decay. Obtained SIR values were correlated to reference LIC to get a relation for calculating LIC from SIR quantities. LIC values and their uncertainties were determined from GRE data and correlated to LIC reference values. For two LIC thresholds, the diagnostic accuracy was determined. RESULTS: LIC was reliably determined from SIR in our patient cohort even for large LIC values. Median of LIC uncertainties was 10 %, and the diagnostic accuracy was 0.92 and 0.91, respectively. CONCLUSION: Determination of even high LIC, resulting in small SIR values, is feasible at 3 T using appropriate SIR analysis. KEY POINTS: • Determination of Liver Iron Concentration (LIC) based on GRE MRI at 3T is feasible even for high LIC levels using Signal Intensiy Ratios. • Relative uncertainty of LIC determined with 3T GRE MRI was below 13 % in most cases. • The patient-management relevant threshold (LIC = 80 µmol/g (4.5 mg/g)) yielded an accuracy of .92 in our cohort. • The proposed method is quick and simple, both in terms of data acquisition and analysis. Citation Format: • Wunderlich AP, Cario H, Bommer M et al. MRI-Based Liver Iron Content Determination at 3T in Regularly Transfused Patients by Signal Intensity Ratio Using an Alternative Analysis Approach Based on R2* Theory. Fortschr Röntgenstr 2016; 188: 846 - 852.

Noninvasive MRI-Based Liver Iron Quantification: Methodic Approaches, Practical Applicability and Significance.

Due to the dependence of transverse relaxation times T2 and T2* on tissue iron content, MRI offers different options for the determination of iron concentration. These are the time-consuming spin-echo sequence as well as the gradient-echo sequence. For the latter, several data analysis approaches have been proposed, with different requirements for acquisition and post-processing: the mathematically challenging R2* analysis and the signal-intensity ratio method with its high demand on the signal homogeneity of MR images. Furthermore, special procedures currently under evaluation are presented as future prospects: quantitative susceptibility imaging, as a third approach for analyzing gradient echo data, and multi-contrast spin-echo using repeated refocusing pulses. MR theory, as far as needed for understanding the methods, is briefly depicted. Key points: • Description of underlying technology of different MRI-based procedures for liver iron quantification• Applicability of these methods in clinical practice• Validity of the methods, i. e. positive and negative predictive value, if available Citation Format: • Wunderlich AP, Cario H, Juchems MS et al. Noninvasive MRI-Based Liver Iron Quantification: Methodic Approaches, Practical Applicability and Significance. Fortschr Röntgenstr 2016; 188: 1031 - 1036.

Liver iron content determined by MRI: spin-echo vs. gradient-echo.

PURPOSE: Liver iron content (LIC) measurement plays a central role in the management of patients with transfusional iron overload. Calculating the LIC with data obtained from standardized MRI sequences represents an attractive alternative diagnostic possibility. The purpose of this study was to compare the LIC measurement obtained with gradient-echo (GRE) sequences to the mean liver proton transverse relaxation (R2) acquired with SE sequences. MATERIALS AND METHODS: 68 patients with iron overload (median age: 24, range: 3-88) underwent 1.5 T MRI for liver iron content measurement. All patients received spin-echo (SE) and gradient-echo (GRE) sequences. RESULTS: The two MRI methods revealed different liver iron content results although a significant correlation was found (r=0.85, p<0.001). Values evaluated using GRE sequences (median: 260 µmol/g dry weight [d. w.], range: 6-732) were generally higher than those obtained by SE examinations (median: 161 µmol /g d. w., range: 5-830). CONCLUSION: In conclusion, our study revealed different results for both MRI measurements, which could lead to different decisions concerning the management of chelation therapy in individual patients.

Shared Copy Number Variation in Simultaneous Nephroblastoma and Neuroblastoma due to Fanconi Anemia.

Concurrent emergence of nephroblastoma (Wilms Tumor; WT) and neuroblastoma (NB) is rare and mostly observed in patients with severe subtypes of Fanconi anemia (FA) with or without VACTER-L association (VL). We investigated the hypothesis that early consequences of genomic instability result in shared regions with copy number variation in different precursor cells that originate distinct embryonal tumors. We observed a newborn girl with FA and VL (aplasia of the thumbs, cloacal atresia (urogenital sinus), tethered cord at L3/L4, muscular ventricular septum defect, and horseshoe-kidney with a single ureter) who simultaneously acquired an epithelial-type WT in the left portion of the kidney and a poorly differentiated adrenal NB in infancy. A novel homozygous germline frameshift mutation in PALB2 (c.1676_c1677delAAinsG) leading to protein truncation (pGln526ArgfsX1) inherited from consanguineous parents formed the genetic basis of FA-N. Spontaneous and induced chromosomal instability was detected in the majority of cells analyzed from peripheral lymphocytes, bone marrow, and cultured fibroblasts. Bone marrow cells also showed complex chromosome rearrangements consistent with the myelodysplastic syndrome at 11 months of age. Array-comparative genomic hybridization analyses of both WT and NB showed shared gains or amplifications within the chromosomal regions 11p15.5 and 17q21.31-q25.3, including genes that are reportedly implicated in tumor development such as IGF2, H19, WT2, BIRC5, and HRAS.

Recent developments in iron chelation therapy.

Since 1962, desferrioxamine (deferoxamine, DFO) has been utilized for the treatment of secondary hemosiderosis. For about 30 years, DFO therapy has been performed as nightly continuous subcutaneous infusion. About 20 years ago, the first oral iron chelator (deferiprone, DFP) was presented. Concerns about potential side effects were responsible for the late acceptance and license of this drug which is limited to the use as second-line therapy for patients with thalassemia major. During recent years, chelation therapy and its evaluation started to progress rapidly. Clinical research and drug development as well as the introduction of new methods for the assessment of iron overload contributed to these advances. By using cardiac T2 (*) MRI it was possible to examine the specific effect of a chelator on myocardial siderosis. Clinical studies using this method indicated superiority of DFP compared to DFO with respect to the treatment of myocardial siderosis. Several retrospective and first prospective clinical trials seem to confirm this observation. In parallel, treatment strategies based on the combination of DFO and DFP have been developed. Using both drugs simultaneously or sequentially, additive and synergistic effects contribute to the fast elimination of iron from different organs at risk for siderotic damage. Deferasirox (DSX) is a recently developed oral chelator which shows good efficacy and tolerability in patients with transfusional hemosiderosis due to various underlying disorders. Long-term studies will define the future importance of DSX for iron chelation treatment. For the first time, there is a choice between three commercially available chelating agents for patients with transfusional iron overload. This will allow a highly effective, individually tailored treatment hopefully leading to a fundamental improvement of patients' life expectancy and quality.

Epidemiology of haemoglobin disorders in Europe: an overview.

OBJECTIVE: As a result of global population movements, haemoglobin disorders (thalassaemias and sickle cell disorders) are increasingly common in the formerly non-indigenous countries of Northern and Western Europe and in the indigenous countries of Southern Europe. This article presents an overview of the changing picture and a method for assessing service needs. METHOD: Data on country of birth or ethnic origin of residents are adjusted to obtain the estimated proportions of residents and births in non-indigenous groups at risk for haemoglobin disorders in European countries. The results are combined with prevalence data in each country of origin to obtain country prevalence estimates. Service indicators (annual tests or other interventions required to ensure equitable delivery of treatment and prevention) are then derived by country. RESULTS: Haemoglobin disorders now occur at comparable frequency throughout Northern, Western and Southern Europe. Annually, there are more affected conceptions in Northern and Western than in Southern Europe, and sickle cell disorders are more common than thalassaemias. There is growing need for health policy-makers to support motivated professionals working to develop optimal patient care, carrier diagnosis, genetic counselling and access to prenatal diagnosis throughout the Region. CONCLUSION: There is a strong case for pan-European collaboration on haemoglobin disorders to share policies, standards and the instruments required to support them. These include methods for needs assessment, service standards, education and information strategies and materials, and methods for evaluating service delivery.

Childhood polycythemias/erythrocytoses: classification, diagnosis, clinical presentation, and treatment.

Polycythemias or erythrocytoses in childhood and adolescence are very rare. Systematic data on the clinical presentation and laboratory evaluations as well as on treatment regimens are sparse. The diagnostic program in absolute erythrocytosis includes extensive clinical, hematological, biochemical, and molecular biological examinations which should be applied following a stepwise algorithm. Absolute erythrocytoses are usually subdivided into primary and secondary forms. Primary erythrocytosis is a condition in which the erythropoietic compartment is expanding independently of extrinsic influences or by responding inadequately to them. Primary erythrocytoses include primary familial and congenital polycythemia (PFCP) due to mutations of the erythropoietin (Epo) receptor gene and the myeloproliferative disorder polycythemia vera. Secondary erythrocytoses are driven by hormonal factors (predominantly by Epo) extrinsic to the erythroid compartment. The increased Epo secretion may represent either a physiologic response to tissue hypoxia, an abnormal autonomous Epo production, or a dysregulation of the oxygen-dependent Epo synthesis. Congenital secondary erythrocytoses are caused, e.g., by hemoglobin variants with increased oxygen affinity, by 2,3-bisphosphoglycerate deficiency, or by mutations in the von Hippel-Lindau gene associated with a disturbed oxygen-dependent regulation of Epo synthesis.

[Beta-thalassemia in Germany. Results of cooperative beta-thalassemia study]. / beta-Thalassämie in Deutschland. Ergebnisse der kooperativen beta-Thalassämie-Studie.

At present, about 300 patients with thalassemia major are living in Germany. Starting in 1991, a multicenter study in Germany has concentrated on identifying all patients suffering from thalassemia as well as on establishing a uniform therapy protocol including follow-up diagnostic procedures. After six years of study, the data of 198 patients suffering from thalassaemia major were analysed. The majority of these patients originate from endemic regions around the Mediterranean Sea. The patient's median age is 13.8 years (range 1-37.5 yrs.). At present, about 20% of patients are older than 21 years. Regarding transfusion therapy, a shortening of the average transfusion interval to 3 weeks in most cases occurred. Throughout the entire period, median baseline haemoglobin concentrations of 10.0 g/dl could be observed. The evaluation of serum ferritin levels revealed considerable differences depending on patients age. 60% of patients in the first decade of life showed good therapeutic results with serum ferritin levels below 1800 ng/ml. In contrast, 52% of patients older than ten years presented with ferritin levels above 2500 ng/ml. During the observation, a decreasing number of patients with ferritin levels above 2500 ng/ml was observed in patients aged 15 to 21 years of age. The situation of patients aged 9 to 15 years proved to be more problematic. More than half of all treated patients presented with siderotic complications as cardiac disease in 13%, liver disease in 21%, impaired glucose metabolism in 14%, hypothyroidism in 24% and hypogonadism in 59% of all patients. These values did not change considerably during the observation apart from an increase of cardiac disorders to 20%. Since the situation concerning siderosis and the lack of compliance proved to be particularly difficult in adolescent patients, further efforts has to concentrate on this age group.

Epidemiological situation and treatment of patients with thalassemia major in Germany: results of the German multicenter beta-thalassemia study.

At present, about 300 patients in Germany suffer from thalassemia major. In 1990, a multicenter study was introduced to identify all thalassemic patients in Germany as well as to establish a uniform therapy protocol, including follow-up diagnostic procedures. After 6 years of study, the data of 203 patients were analyzed. The majority originate from endemic regions around the Mediterranean Sea. The median age of the patients is 13.8 years (range 1-37.5 years). At present, about 20% of the patients are older than 21 years. Regarding transfusion therapy, a shortening of the average transfusion interval to 3 weeks in most cases occurred. Throughout the entire period, median baseline hemoglobin concentrations of 10.0 g/dl were observed. The evaluation of serum ferritin levels revealed considerable differences, depending on the patients' age. Thalassemic patients in the first decade of life generally presented with good therapeutic results; serum ferritin levels were below 1800 ng/ml in 76/102 patients (75%) upon entry into the study. In contrast, 51/98 patients (52%) older than 10 years had ferritin levels above 2500 ng/ml. More than half of all treated patients presented with siderotic complications such as cardiac disease in 20/157 (13%), liver disease in 32/157 (21%), impaired glucose metabolism in 22/157 (14%), hypogonadism in 39/66 (59%), and hypothyroidism in 38/157 (24%) who were under treatment at the time of first survey. Since the situation concerning siderosis and the lack of compliance proved to be particularly difficult with adolescent patients, further efforts should concentrate on this age-group.

Congenital erythrocytosis and polycythemia vera in childhood and adolescence.

Polycythemia vera - the most frequent form of a primary erythrocytosis in adult patients - represents an extremely rare disease in pediatric and juvenile patients as do congenital primary and secondary erythrocytoses. Frequently, in patients with these diseases clinical problems do not occur before adulthood. Systematic data on clinical and laboratory evaluations as well as on treatment regimens are sparse. In addition, in the majority of cases with congenital erythrocytosis, the etiology is unknown. For those reasons, a protocol (PV-ERY-KA 03) for the systematic collection of clinical, hematological, biochemical, biological as well as treatment data of children and adolescents with polycythemia vera or congenital erythrocytosis including the hemoglobinopathies with high affinity hemoglobin, familial 2,3-BPG deficiencies, and those of unknown origin, has been developed. These data are combined with molecular analyses which focus initially on EPO-receptor and vHL-gene examination, but will later be extended into presently unexplored pathophysiologic regulatory circuits. In addition, pathophysiologic changes due to the erythrocytosis will be studied. The co-ordinated medical care for patients with those rare diseases within a collaborative trial accompanied by scientific projects is aimed at the improvement of the treatment of these patients as well as to a better understanding of the underlying biological processes.

Treatment with hydroxyurea in thalassemia intermedia with paravertebral pseudotumors of extramedullary hematopoiesis.

Excessive ineffective erythropoiesis in thalassemia intermedia may cause paravertebral pseudotumors of extramedullary hematopoiesis. Due to the proximity to the spinal canal, these paravertebral masses carry the risk of severe neurological damage. Treatment strategies include hypertransfusion, radiotherapy, and laminectomy. Hydroxyurea, stimulating fetal hemoglobin synthesis, may represent an alternative therapeutic approach. We report on a 26-year-old patient suffering from thalassemia intermedia with progressive anemia symptoms and presenting multiple intrathoracic paravertebral pseudotumors of extramedullary hematopoiesis. Hypertransfusion therapy and splenectomy were followed by regular transfusion (baseline hemoglobin 10 g/dl) and chelation with desferrioxamine. With this treatment, clinical symptoms disappeared, paravertebral hematopoietic masses did not progress, but severe hemosiderosis developed within a few years. Hydroxyurea therapy was initiated to increase the efficacy of erythropoiesis, thereby reducing the required transfusion volume but suppressing concomitantly further expansion of extramedullary hematopoiesis, and finally leading to a reduction of transfusional iron load. Treatment was started with 4 mg/kg per day and stepwise increased to 12.5 mg/kg per day. The fetal hemoglobin concentration increased from 4.5 to 5.5 g/dl after 1 year and to 9.9 g/dl after 2 years of treatment. The yearly transfusion volume was halved during the 1st year of treatment. At present, after 26 months of treatment, the patient has been transfusion-independent for 10 months. Serum ferritin levels decreased from 2844 to 1335 ng/ml. Size and shape of paravertebral hematopoietic pseudotumors remained stable. No side effects of hydroxyurea have been observed. In thalassemia intermedia patients with extramedullary hematopoiesis, hydroxyurea may lead to independence from regular transfusion therapy without further expansion of ectopic hematopoietic tissue.

A microdeletion syndrome due to a 3-Mb deletion on 19q13.2--Diamond-Blackfan anemia associated with macrocephaly, hypotonia, and psychomotor retardation.

We report on a boy with congenital pure red blood cell aplasia [Diamond Blackfan anemia (DBA)] and severe congenital hypotonia, macrocephaly, hypertelorism, a broad and tall forehead, medial epicanthus, and facial hypotonia with mouth-breathing and drooling, an affable and out-going personality, and a general psychomotor retardation. These features show similarity to the phenotype of the X-linked FG syndrome. DBA was diagnosed at the age of 4 months, and the boy underwent treatment with transfusion and with prednisolone. He had a normal 46, XY karyotype, but fluorescence in situ hybridization (FISH) analysis to metaphase chromosomes revealed a 3-Mb deletion on 19q13.2. This chromosomal region has previously been linked to the DBA phenotype and one 19q13 microdeletion has been identified in a patient with DBA. This deletion coincides with the deletion reported here. We suggest that the complex phenotype of our patient, including both DBA and the associated features, represent a microdeletion syndrome.