Jon Helgestad

Immune thrombocytopenic purpura in childhood in Norway: a prospective, population-based registration.

A prospective, population-based registration of children with immune thrombocytopenic purpura (ITP) was performed in Norway in 1996 and 1997. Ninety-two cases were identified, indicating an incidence of 5.3 per 100,000 children under 15 years. The sex ratio (female/male) was 1.2/1. Fifty six percent presented with cutaneous signs only. The lowest platelet count was < 20x109

Pediatric Venous and Arterial Noncerebral Thromboembolism in Denmark: A Nationwide Population-Based Study

OBJECTIVE To assess the incidence rate (IR), changes in IR over time, risk factors, treatment, and outcomes of pediatric noncerebral thromboembolism (TE). STUDY DESIGN The study included all patients aged 0 to 18 years diagnosed with first-ever noncerebral venous thromboembolism (VTE) and/or arterial TE in Denmark between 1994 and 2006. Patients were identified in national registries, followed by validation of diagnoses by medical records review. RESULTS We confirmed 331 cases of VTE and 46 cases of arterial TE during 15.8 million person-years of observation, with corresponding IRs of 2.09 and 0.29 per 100 000 person-years. The IR peaked in infancy (age <1 year) for both VTE and arterial TE, with an additional peak among adolescents (age 15 to 18 years) for VTE. Boys predominated in IR of VTE in infancy, whereas girls did so in adolescence (P < .01). The IRs of VTE and arterial TE remained stable during the study period, but with an trend toward increasing VTE in 2001 to 2006 (P = .064). Underlying diseases/external triggers were present in 86.6% of the patients, and thrombophilia was present in 47.9% of the VTE cases. All-cause and TE-related 30-day case fatalities were 4.0% and 1.6%, respectively. CONCLUSIONS We found age- and sex-related disparities in the IRs of pediatric VTE and arterial TE, but insignificant changes in IR from 1994 to 2006.

Purification of human blood basophils by negative selection using immunomagnetic beads

A simple and rapid method for isolating highly purified and functionally intact basophils from normal human blood is described. Blood from healthy volunteers was centrifuged through a two layer Percoll density gradient. The majority of the basophils were recovered between Percoll layers with densities of 1.070 and 1.080, constituting 45.6% of total leukocytes. Lymphocytes, monocytes and neutrophils were extracted from this fraction using a panel of mabs in a direct or indirect selection procedure using immunomagnetic beads (Dynabeads) coated with sheep anti-mouse IgG. These negative immunoselection procedures produced a high yield of basophils with a mean purity of 97.8% (range 93.0-99.5%) and 97.0% (range 96.2-99.0%) using the direct and indirect method, respectively. The cells isolated by this method are viable, release histamine to various stimuli in a normal manner, and appear morphologically normal in transmission electron microscopy.

Cerebral atypical teratoid/rhabdoid tumor of infancy: Long-term survival after multimodal treatment, also including triple intrathecal chemotherapy and gamma knife radiosurgery: Case report

Cerebral atypical teratoid/rhabdoid tumors (AT/RT) of infancy are highly malignant and have a poor prognosis. The authors report on one case with long-term survival. The patient was a 1 year-old boy presenting with a large AT/RT in the right temporal lobe. He was treated with complete surgery, followed by multiagent chemotherapy. Later he had a second resection and intrathecal chemotherapy and Gamma knife radiosurgery was added to the treatment. Except for a well-controlled temporal epilepsy, the boy is doing well after 6 years follow-up. AT/RT should be treated in a multimodal way. Intrathecal chemotherapy and Gamma knife radiosurgery of single recurrent or residual tumors might increase survival.

Paediatric arterial ischaemic stroke and cerebral sinovenous thrombosis in Denmark 1994–2006: A nationwide population-based study

Aim:  To assess the incidence rates (IR), clinical characteristics, risk factors, treatment and outcomes of paediatric arterial ischaemic stroke (AIS) and cerebral sinovenous thrombosis (CSVT).

Cerebral sinus venous thromboses in children with acute lymphoblastic leukaemia - a multicentre study from the Nordic Society of Paediatric Haematology and Oncology.

We present a prospective multicentre cohort of 20 children with acute lymphoblastic leukaemia (ALL) and cerebral sinus venous thrombosis (CSVT). The study covers a period of 5 years and comprises 1038 children treated according to the Nordic Society of Paediatric Haematology and Oncology (NOPHO) ALL 2008 protocol. The cumulative incidence of CSVT was 2%. Sixteen of the thromboses were related to asparaginase and 16 to steroids. Most CSVTs occurred in the consolidation phase. Nearly all were treated with low molecular weight heparin without bleeding complications. Mortality related to CSVT directly or indirectly was 10%, emphasizing the importance of this complication.

Prolonged intrathecal chemotherapy replacing cranial irradiation in high-risk acute lymphatic leukaemia: Long-term follow up with cerebral computed tomography scans and endocrinological studies

Cranial irradiation in children with acute lymphatic leukaemia (ALL) decreases the risk of CNS relapse but is associated with serious long-term side-effects. We present the long-term outcome of 21 children with high-risk ALL who received prolonged intrathecal chemotherapy instead of the recommended cranial irradiation. Intrathecal triple therapy (methotrexate, hydrocortisone, and cytarabine) was administered every 2nd month throughout the maintenance phase. The average number of courses of intrathecal methotrexate was 8.7 and of triple 9.0. The 5-year event-free survival was 79%. No CNS relapses occurred. CT scan was performed at diagnosis, at cessation of therapy, and 3 years thereafter. No density abnormalities, pathological contrast enhancement, ventricular dilatation, or calcifications were found. One child showed cortical atrophy both at diagnosis and at cessation of therapy. There was a slight decrease in height SDS with time but no change in weight SDS. Delayed bone age was found in 5 children. No abnormalities of growth hormone, thyroid, adrenal, or gonadal function were observed.ConclusionThe study indicates that extended intrathecal chemotherapy in children with high-risk ALL may provide an effective protection from CNS relapses and is associated with a low risk of long-term side-effects.

Characterization of a new malignant human T-cell line (PFI-285) sensitive to ascorbic acid

Abstract: A new malignant human T‐cell line‐labelled PFI‐285‐has been isolated from a boy with malignant lymphoma. Morphologically, the cells had characteristics of malignant lymphoid cells. The cells presented surface antigens as early cortical lymphocytes and proliferated non‐adherently as single cells, independent of T‐cell growth factor (IL‐2), in liquid culture. The cells had undetectable levels of receptors for IL‐2, were not clonogenic in soft agar, but did form tumors in nude mice. Their establishment and continuous growth in vitro was dependent on the number of cells inoculated and on the growth medium used. Cytogenetic alteration, HTLV‐1 or reverse transcriptase activity were not detected. The production of known T‐cell derived lymphokines such as IL‐2, B‐cell growth factor(s), α‐interferon or granulocyte/macrophage colony stimulating or inhibiting factor(s) was not detected. The cells had 5–8% natural killer (NK)‐cell activity against NK‐cell sensitive target cells (K562) and were not sensitive for NK cells. A most unusual characteristic was the pronounced sensitivity of the cells to ascorbic acid. Concentrations down to 50 μmol/l killed the cells within hours.

Vitamin C and thiol reagents promote the in vitro growth of murine granulocyte/macrophage progenitor cells by neutralizing endogenous inhibitor(s)

SummaryGrowth of murine hemopoietic cells in culture requires the presence of a stimulator of stem cell proliferation, “colony stimulating factor” (CSF). A widely used source of CSF is lung conditioned medium (LCM). We have earlier shown that the great variability of CSF aktivities in different batches of LCM is due to varying amounts of inhibitor(s). The present study expands the observation that the addition of ascorbic acid to the murine bone marrow soft agar assay system removes the inhibitory activity. The vitamin probably acts as an antioxidant or free radical scavenger, since addition of reduced (but not oxidized) glutathione, cysteine, dithiothreitol or 2-mercaptoethanol to the cultures also inactivates the endogeneous inhibitor.Cysteine and glutathione gave the highest colony numbers, were active at concentrations present in body fluids and did not inhibit colony growth even at concentrations ten times higher than optimum. No synergistic effects could be observed between the different antioxidants. At optimum concentration (usually 0.45 mmol/l) the otherwise bell-shaped dose-response curve for conditioned medium changed to a sigmoid curve. Antioxidants had no growth promoting effect in the absence of CSF.The presence of cysteine or vitamin C revealed CSF-like activity in conditioned media of tissues not considered to be potent producers of such factors. It has been reported that individual batches of foetal calf serum contain different levels of reduced glutathione, and we suggest that one of the batch variable growth regulators in foetal calf serum may be reduced glutathione.The results indicate a possible physiological role of antioxidants in granulopoiesis and suggest that cysteine or reduced glutathione should be freshly added to culture systems assaying CSF and/or granulocyte macrophage progenitor cells.

Bone marrow aspiration technique may have an impact on therapy stratification in children with acute lymphoblastic leukaemia

Morphological evaluation of early response to chemotherapy and measurement of minimal residual disease by flow cytometry or PCR are being used for evaluation of prognosis and treatment stratification in children with acute lymphoblastic leukaemia (ALL).