Andrica de Vries

Molecular basis of juvenile myelomonocytic leukemia

Juvenile myelomonocytic leukemia (JMML) is classified as a combined myeloproliferative/myelodysplastic disease by the World Health Organization and accounts for less than 3% of all childhood hematologic malignancies.[1][1],[2][2] Children typically present at young age (median age at diagnosis: two

Carbon monoxide poisoning mimicking long-QT induced syncope

Carbon monoxide (CO)poisoning is a rare cause of QT prolongation, and is therefore easily missed. The case of a patient with unexplained syncope and QT prologation on the electrocardiogram that turned out to be related to CO poisoning is reported here. In patients with QT prolongation, uncommon causes also should be looked for.

LIN28B overexpression defines a novel fetal-like subgroup of juvenile myelomonocytic leukemia

Juvenile myelomonocytic leukemia (JMML) is a rare and aggressive stem cell disease of early childhood. RAS activation constitutes the core component of oncogenic signaling. In addition, leukemic blasts in one-fourth of JMML patients present with monosomy 7, and more than half of patients show elevated age-adjusted fetal hemoglobin (HbF) levels. Hematopoietic stem cell transplantation is the current standard of care and results in an event-free survival rate of 50% to 60%, indicating that novel molecular-driven therapeutic options are urgently needed. Using gene expression profiling in a series of 82 patient samples, we aimed at understanding the molecular biology behind JMML and identified a previously unrecognized molecular subgroup characterized by high LIN28B expression. LIN28B overexpression was significantly correlated with higher HbF levels, whereas patients with monosomy 7 seldom showed enhanced LIN28B expression. This finding gives a biological explanation of why patients with monosomy 7 are rarely diagnosed with high age-adjusted HbF levels. In addition, this new fetal-like JMML subgroup presented with reduced levels of most members of the let-7 microRNA family and showed characteristic overexpression of genes involved in fetal hematopoiesis and stem cell self-renewal. Lastly, high LIN28B expression was associated with poor clinical outcome in our JMML patient series but was not independent from other prognostic factors such as age and age-adjusted HbF levels. In conclusion, we identified elevated LIN28B expression as a hallmark of a novel fetal-like subgroup in JMML.

Emotional distress in 652 dutch very long-term survivors of childhood cancer, using the hospital anxiety and depression scale (HADS)

Background: After a more successful treatment of pediatric cancer, the number of childhood cancer survivors is progressively increasing. Consequently, awareness of psychological late sequelae is important. Procedure: The Hospital Anxiety and Depression Scale (HADS) was used as a screening tool for emotional distress in a single center cohort of 652 childhood cancer survivors (median age 23 y [range, 15 to 46 y], median follow-up time 15 y [range, 5 to 42 y]). Results were compared with a control group of 440 Dutch subjects. A higher HADS score linearly reflect a higher level of emotional distress, and a score ≥15 is indicative of clinically significant emotional distress. Results: Mean HADS score of the childhood cancer survivors was not different from the control group (P=0.38). Survivors exposed to global central nervous system (CNS) irradiation had a significantly higher HADS score than the control group (8.3±6.6; P=0.05) as well as other survivors (P=0.01). Forty-three survivors (7%) had a HADS score ≥15. Survivors with a HADS score ≥15 were variously spread over the diagnostic-related and treatment-related subgroups. Linear regression analysis showed that high educational achievement (&bgr;=−1.28; P<0.01) and age at the time of the study (&bgr;=0.08; P=0.03) were both significantly associated with the HADS score. Conclusions: Emotional distress does not occur more often in childhood cancer survivors than in the normal population. No disease-related or treatment-related variable was independently associated with emotional distress.

Role of mutation independent constitutive activation of FLT3 in juvenile myelomonocytic leukemia

FLT3 gene mutations have been identified as prognostic factors in myeloid malignancies. Furthermore, FLT3 can be activated by wild type overexpression or ligand-dependent in leukemic cells co-expressing FLT3 ligand (FLT3L). So far no data are available on FLT3/FLT3L expression and activation in JMML. In 51 clinical JMML samples, activating mutations were screened, FLT3 and FLT3L mRNA levels were assessed and the sensitivity of JMML cells to the FLT3 inhibitor PKC412 was tested by MTT assays. No evidence for constitutively activation of FLT3/FLT3L was found in JMML, indicating that FLT3 inhibitors are unlikely to be effective in JMML.

Successful treatment of congenital acute myeloid leukemia (AML-M6) in a premature infant.

Congenital acute myeloid leukemia (AML), and especially AML-M6 is a rare disease with a poor prognosis. Moreover, reports of treatment outcome of congenital AML-M6 in premature infants are not available. We report the first treated case of congenital AML-M6 in a premature girl, who received a full AML protocol. She presented with blueberry-muffin spots, anemia, high white blood cell count, and serious cardiopulmonary distress. Peripheral blood smears showed AML-M6 blasts. After treatment with a sequential low-dose cytarabine after birth and full-dose AML treatment according to the MRC-12 protocol at the age of 2 months, she now is in continuous complete remission for 4 years.

Gonadal function recovery in very long-term male survivors of childhood cancer

BACKGROUND Although gonadal toxicity has been reported, no data are available on recovery of gonadal function in very long-term survivors of childhood cancer. Inhibin B is a novel reliable serum marker which has been shown to be of value in childhood cancer survivor studies to identify risk groups for impaired gonadal function, but consecutive long-term follow-up studies using serum inhibin B as a marker are not available. OBJECTIVE To evaluate possible recovery of gonadal dysfunction over time in adult male survivors of childhood cancer. METHODS In this retrospective study, adult male long-term childhood cancer survivors (n=201) who visited our outpatient late effects clinic were included and we used inhibin B as a surrogate marker for gonadal function. RESULTS Median age at diagnosis was 5.9 years (range 0.0-17.5) and discontinuation of treatment was reached at a median age of 8.2 years (range 0.0-20.8). Inhibin B levels were first measured after a median follow-up time of 15.7 years (range 3.0-37.0). Median interval between the first (T1) and second measurement (T2) was 3.3 years (range 0.7-11.3). Median inhibin B level was 127 ng/L (range 5-366) at T1 and 155 ng/L (range 10-507) at T2. The prediction model suggests that inhibin B levels do not normalise in survivors with a very low Inhibin B level at T1. CONCLUSIONS Our results suggest that recovery of gonadal function is possible even long after discontinuation of treatment. However, this recovery does not seem to occur in survivors who already reached critically low inhibin B levels after discontinuation of treatment.

HLA-identical umbilical cord blood transplantation from a sibling donor in juvenile myelomonocytic leukemia

As recently described by Flotho et al . juvenile myelomonocytic leukemia (JMML) is a rare type of childhood leukemia not only characterized by young age, hepatosplenomegaly, thrombocytopenia and monocytosis, but also by molecular aberrations in the RAS-RAF-MEK-ERK signaling pathway and GM-CSF-

LIN28B is over-expressed in specific subtypes of pediatric leukemia and regulates lncRNA H19

LIN28B is an RNA-binding protein with an oncofetal expression pattern. High LIN28B expression is crucial during human embryogenesis and is down-regulated in most tissues after birth.[1][1] However, reactivation during oncogenesis is common in a plethora of adult cancers, including leukemia, and was

Malignancy and Mortality in Pediatric-onset Inflammatory Bowel Disease: A Systematic Review

Background Cancer and death are the most severe outcomes that affect patients with inflammatory bowel disease (IBD). These outcomes are even more severe if they occur at a young age but are rare, even in the general population. We conducted a systematic review to provide an overview of all reported pediatric (PIBD) patients with severe outcome. Methods A literature search identified publications that reported development of cancer or fatal outcome in PIBD patients. Studies were eligible for inclusion when (1) article written in English, (2) original data, (3) individual patient information, (4) full text available, (5) study population consisting of patients diagnosed with IBD under the age of 19 years, and (6) who developed malignancy or fatality at any point later in life. Results A total of 98 included studies comprised data of 271 PIBD patients who developed cancer and/or fatal outcome at any point later in life. Meta-analysis demonstrated an increased risk for cancer in PIBD patients (pooled standardized incidence ratio 2.23, 95% CI: 1.98-2.52). The most frequent type of non-fatal cancer was lymphoma, whereas colorectal carcinomas were the most frequently reported type of fatal cancer in PIBD patients and were particularly associated with primary sclerosing cholangitis. The majority of patients with noncancer-related fatal outcomes were diagnosed with ulcerative colitis and most often died due to infectious complications or severe disease-associated complications. Conclusions The data in this review confirm that PIBD associated malignancy and mortality are rare and detailed clinical characteristics are limited. Prospective and international collaborations are needed to obtain more detailed patient-specific information, which is necessary to investigate the relationship between severe outcomes in PIBD patients and the currently used therapeutic strategies. 10.1093/ibd/izx104_video1izx104_Video5754026434001.