Michael M. Schündeln

Effects of RANK-Ligand Antibody (Denosumab) Treatment on Bone Turnover Markers in a Girl With Juvenile Paget's Disease

CONTEXT Juvenile Pagets disease (JPD) is an extremely rare, yet painful and debilitating bone disease with onset occurring during early childhood. JPD can be caused by loss of function of osteoprotegerin, resulting in subsequent stimulation of osteoclasts via the receptor activator of nuclear factor-κB (RANK) pathway. Increased bone turnover and lack of bone modeling lead to severe deformities, frequent fractures, short stature, and loss of hearing. SETTING The treatment for JPD is challenging and has previously been based on administration of either calcitonin or bisphosphonates. However, with the development of denosumab, a receptor activator of nuclear factor-κB-ligand (RANKL) antibody, a treatment targeting the pathophysiology of JPD may be available. We report the effects of denosumab treatment on an 8-year-old girl with a severe form of JPD. PATIENT Before starting the denosumab treatment regimen, the patient had been treated for 3.5 years with iv pamidronate. INTERVENTION AND OUTCOME The administration of denosumab resulted in improved disease control compared with bisphosphonate, as assessed by monitoring markers of bone turnover. Alkaline phosphatase levels dropped within the normal range and remained at normal levels for 5 months after the final dose of denosumab. Additionally, bone pain was more efficiently controlled with denosumab. However, concomitant with the first injection, severe hypocalcemia developed, for which the patient was hospitalized and iv calcium supplementation was required for 13 days. CONCLUSIONS Denosumab appears to be significantly effective for osteoclast inhibition for the treatment of JPD. However, in our patient, denosumab administration was associated with severe hypocalcemia, indicating that close monitoring of calcium levels is required during treatment.

Incidence of second cancers after radiotherapy and systemic chemotherapy in heritable retinoblastoma survivors: A report from the German reference center

Survivors of heritable retinoblastoma carry a high risk to develop second cancers. Eye‐preserving radiotherapy raises this risk, while the impact of chemotherapy remains less defined.

Maternal Vitamin D Status in Preeclampsia: Seasonal Changes Are Not Influenced by Placental Gene Expression of Vitamin D Metabolizing Enzymes

Preeclampsia, a hypertensive disorder in pregnancy develops in 2–8% of pregnancies worldwide. Winter season and vitamin D deficiency have been associated with its onset. Objective To investigate the influence of season on maternal vitamin D status and placental vitamin D metabolism. Methods 25-OH vitamin D and 1,25-(OH)2 vitamin D were measured in maternal serum obtained during the winter or summer months from 63 pregnant women at delivery (43 healthy, 20 preeclampsia). In a subgroup, mRNA expression of CYP24A1 (24-hydroxylase), CYP27B1 (1α-hydroxylase) and VDR (vitamin D receptor) were quantified by real time PCR in placental samples of 14 women with normal pregnancies and 13 with preeclampsia. Results In patients with preeclampsia,25-OH vitamin D levels were lower, but differed significantly from controls only in summer (18.21±17.1 vs 49.2±29.2 ng/mL, P<0.001), whereas 1,25-(OH)2 vitamin D levels were significantly lower only in winter (291±217 vs 612.3±455 pmol/mL, P<0.05). A two-factorial analysis of variance produced a statistically significant model (P<0.0001) with an effect of season (P<0.01) and preeclampsia (P = 0.01) on maternal 25-OH vitamin D levels, as well as a significant interaction between the two variables (P = 0.02). Placental gene expression of CYP24A1, CYP27B1, and VDR did not differ between groups or seasons. A negative correlation between placental gene expression of CYP24A1 and CYP27B1 was observed only in healthy controls (r = −0.81, P<0.0001). Summary Patients with preeclampsia displayed lower vitamin D serum levels in response to seasonal changes.The regulation of placental CYP24A1, but not of the VDR or CYP27B1 might be altered in preeclampsia.

Impairment of Bone Health in Pediatric Patients with Hemolytic Anemia

Introduction Sickle cell anemia and thalassemia result in impaired bone health in both adults and youths. Children with other types of chronic hemolytic anemia may also display impaired bone health. Study Design To assess bone health in pediatric patients with chronic hemolytic anemia, a cross-sectional study was conducted involving 45 patients with different forms of hemolytic anemia (i.e., 17 homozygous sickle cell disease and 14 hereditary spherocytosis patients). Biochemical, radiographic and anamnestic parameters of bone health were assessed. Results Vitamin D deficiency with 25 OH-vitamin D serum levels below 20 ng/ml was a common finding (80.5%) in this cohort. Bone pain was present in 31% of patients. Analysis of RANKL, osteoprotegerin (OPG) and osteocalcin levels indicated an alteration in bone modeling with significantly elevated RANKL/OPG ratios (control: 0.08+0.07; patients: 0.26+0.2, P = 0.0007). Osteocalcin levels were found to be lower in patients compared with healthy controls (68.5+39.0 ng/ml vs. 118.0+36.6 ng/ml, P = 0.0001). Multiple stepwise regression analysis revealed a significant (P<0.025) influence of LDH (partial r2 = 0.29), diagnosis of hemolytic anemia (partial r2 = 0.05) and age (partial r2 = 0.03) on osteocalcin levels. Patients with homozygous sickle cell anemia were more frequently and more severely affected by impaired bone health than patients with hereditary spherocytosis. Conclusion Bone health is impaired in pediatric patients with hemolytic anemia. In addition to endocrine alterations, an imbalance in the RANKL/OPG system and low levels of osteocalcin may contribute to this impairment.

How Eye-Preserving Therapy Affects Long-Term Overall Survival in Heritable Retinoblastoma Survivors

PURPOSE Intraocular retinoblastoma is curable, but survivors with a heritable predisposition are at high risk for second malignancies. Because second malignancies are associated with high mortality, prognostic factors for second malignancy influence long-term overall survival. This study investigates the impact of all types of eye-preserving therapies on long-term survival in the complete German cohort of patients with heritable retinoblastoma. PATIENTS AND METHODS Overall survival, disease staging using international scales, time period of diagnosis, and treatment type were analyzed in the 633 German children treated at the national reference center for heritable retinoblastoma. RESULTS The 5-year overall survival of children diagnosed in Germany with heritable retinoblastoma between 1940 and 2008 was 93.2% (95% CI, 91.2% to 95.1%), but long-term mortality was increased compared with patients with nonheritable disease. Overall survival correlated with tumor staging, and 92% of patients were diagnosed with a favorable tumor stage (International Retinoblastoma Staging System stage 0 or I). Despite a 5-year overall survival of 97.4% (95% CI, 96.0% to 98.8%) in patients with stage 0 or I, only 79.5% (95% CI, 74.2% to 84.8%) of these patients survived 40 years after diagnosis. Long-term overall survival was reduced in children treated with eye-preserving radiotherapy compared with enucleation alone, and adding chemotherapy aggravated this effect. CONCLUSION The benefits of preserving vision must be balanced with the impact of eye-preserving treatments on long-term survival in heritable retinoblastoma, and the genetic background of the patient influences choice of eye-preserving treatment. Germline RB1 genetic analysis is important to identify heritable retinoblastoma among unilateral retinoblastoma cases. Eye-preserving radiotherapy should be carefully considered in patients with germline RB1 mutations. Life-long oncologic follow-up is crucial for all retinoblastoma survivors, and less detrimental eye-preserving therapies must be developed.

Pediatric Survivors of Retinoblastoma Are at Risk for Altered Bone Metabolism After Chemotherapy Treatment Early in Life

Survivors of childhood cancer frequently suffer from endocrine late effects, which are, at least partly, attributed to toxic effects of chemotherapy. Treatment of retinoblastoma typically involves chemotherapy at a very young age. The authors conducted a cross-sectional study to assess bone health in a pediatric cohort of 33 survivors of retinoblastoma (mean age: 4.4 years) who had undergone chemotherapy treatment at an especially young age (mean age: 0.76 years). Of these patients, 14 had unilateral and 19 bilateral retinoblastoma. Polychemotherapy consisted of treatment with cyclophosphamide, etoposide, vincristine, and carboplatin. Ten patients had undergone external beam radiotherapy. Clinical and biochemical parameters of growth, pubertal development, and bone health were obtained. A vitamin D deficiency was found in 51.7% of the patients, and 13.7% of patients displayed severe vitamin D deficiency. Secondary hyperparathyroidism and altered readings for bone formation or resorption markers were present in 15%. Nine percent reported bone pain or experienced fractures of the long bones after primary diagnosis. No difference between children with bilateral and unilateral disease or irradiated versus nonirradiated children was observed. The parameters of thyroid function, growth, and pubertal development were within age-appropriate norms in almost all children. In conclusion, altered parameters of bone health can be present in survivors of retinoblastoma at a young age and warrant regular follow-up in these children. The endocrine hypothalamic-pituitary axes, however, were not impaired at this early age in this group of survivors of retinoblastoma.

Quantification of Nucleated Cells, CD34-Positive Cells and CFU-GM Colonies in Single Bone Marrow Samples and Bone Marrow Harvests Derived from Healthy Children

Little is known regarding bone marrow (BM) cellularity, CD34+ fraction, and CFU-GM colony formation in relation to age and whether healthy children require a reference range distinct from healthy adults. We therefore analyzed a series of single BM aspirates from 45 healthy children who were evaluated as potential BM donors. Thirty-three of these children subsequently donated BM. We quantified the nucleated cell count, fraction of CD34+ cells, and number of CFU-GM colonies in single aspirates and BM harvests. Single aspirates displayed a mean nucleated cell count of 31.3 × 106 cells/mL, a mean fraction of 1.17% CD34+ cells, and a mean colony forming potential of 66.6 CFU-GM/105 cells. Harvests yielded the same number of nucleated cells but increased numbers of CD34+ cells and CFU-GM compared with single aspirates. The mean nucleated cell count in BM harvests was 31.1 × 106 /mL with a mean fraction of 1.95% CD34+ cells and a mean of 112.4 CFU-GM colonies/105 cells. The concentration of nucleated cells was elevated compared with reported adult counts, while CD34+ percentage and CFU-GM counts were similar. In this series of healthy children, the fraction of CD34+ cells, CFU-GM colonies, and nucleated cells decreased with age. We did not identify gender specific differences. To our knowledge, this represents the first comprehensive study of CD34+ cell fraction, CFU-GM counts, and nucleated cell numbers in the BM of healthy children. The findings provide valuable information for practical use for BM transplantation and contribute to the understanding of hematopoiesis from birth to adulthood.

Loss of Functional Osteoprotegerin: More Than a Skeletal Problem.

Introduction Juvenile Pagets disease (JPD), an ultra-rare, debilitating bone disease due to loss of functional osteoprotegerin (OPG), is caused by recessive mutations in TNFRFSF11B. A genotype-phenotype correlation spanning from mild to very severe forms is described. Aim This study aimed to describe the complexity of the human phenotype of OPG deficiency in more detail and to investigate heterozygous mutation carriers for clinical signs of JPD. Patients We investigated 3 children with JPD from families of Turkish, German, and Pakistani descent and 19 family members (14 heterozygous). Results A new disease-causing 4 bp-duplication in exon 1 was detected in the German patient, and a microdeletion including TNFRFSF11B in the Pakistani patient. Skeletal abnormalities in all affected children included bowing deformities and fractures, contractures, short stature and skull involvement. Complex malformation of the inner ear and vestibular structures (2 patients) resulted in early deafness. Patients were found to be growth hormone deficient (2), displayed nephrocalcinosis (1), and gross motor (3) and mental (1) retardation. Heterozygous family members displayed low OPG levels (12), elevated bone turnover markers (7), and osteopenia (6). Short stature (1), visual impairment (2), and hearing impairment (1) were also present. Conclusion Diminished OPG levels cause complex changes affecting multiple organ systems, including pituitary function, in children with JPD and may cause osteopenia in heterozygous family members. Diagnostic and therapeutic measures should aim to address the complex phenotype.

Development of Port-Site Metastases Following Thoracoscopic Resection of a Neuroblastoma

We report a 26‐month‐old female who developed port‐site metastases of a neuroblastoma following minimally invasive thoracoscopic interventions. After diagnosis of an intrathoracic low‐risk neuroblastoma and 6 months of observation, she developed respiratory problems. She subsequently underwent total resection of a locally progressive tumor via thoracoscopy. Six months later, she developed local relapse and subcutaneous metastases within the thoracic wall. These port‐site metastases were most likely iatrogenic. After excision of metastases, the residual tumor responded well to salvage chemotherapy. The patient has remained in remission for over 4 years. Pediatr Blood Cancer

Orbital Compression Syndrome in a Child with Sickle Cell Disease

A n 8-year-old boy with homozygous sickle cell disease presented with a 2-day history of headache, abdominal pain, and acute, painful bilateral orbital swelling and proptosis. After admission, he developed a fever of 39.3 C. Laboratory evaluation revealed reduced hemoglobin (6.5 g/dL) and elevated levels of reticulocytes (13.2%), leukocytes (18.6 cells/nL), serum C-reactive protein (25 mg/dL), and serum lactate dehydrogenase (922 U/L). An ophthalmologic examination revealed impaired lateral eye motility but normal visual acuity, fundus, eye pressure, and pupillary reaction and no signs of relative afferent pupillary defect. Magnetic resonance imaging revealed bilateral hematoma of the lateral orbital cavity with dislocation of both lateral rectus muscles, consistent with orbital compression syndrome (OCS). OCS is a rare sequela of subperiosteal hematoma due to orbital wall infarction during a sickle cell crisis. Therapy with glucocorticoids, hydration, analgesia, antibiotics, and red blood cell transfusion was subsequently initiated. Visual acuity remained normal on daily follow-ups, and pain symptoms resolved within 3 days. Patients with sickle cell disease and bilateral orbital swelling should undergo immediate evaluation for OCS, which may result in optic nerve compression and vision loss if left untreated. n