Hair selenium status in children with leukemia and lymphoma.

Selenium (Se) is a trace element contributing to the structure of antioxidant system that saves cells from reactive oxygen species. Low serum Se levels have been reported in pediatric and adult patients with cancers. On the other hand, hair Se levels, predicting the long-term body Se status, have been reported in only adult patients with cancer. The aim of the study was to investigate the hair Se status in children with newly diagnosed lymphoid malignancies and the relation between malnutrition and Se deficiency. Thirty patients with leukemia (n=17) and lymphoma (n=13), and 25 healthy controls were enrolled to the study. Se was determined with atomic absorption spectrophotometrical method. Hair Se levels of the patients were significantly lower than those of control group [666.96+/-341.46 ng/g vs. 1019.22+/-371.83 ng/g (P<0.001)]. Children with lymphoma had lower Se than the children with acute lymphoblastic leukemia but not statistically significant [547.03+/-283.67 ng/g vs. 758.67+/-361.05 ng/g (P>0.05)]. Malnourished patients (11/30) had lower hair Se levels (483.51+/-235.55 ng/g) than those of the controls (P=0.036), whereas the Se levels of the patients who had no malnutrition (773.17+/-352.92 ng/g) were also lower than those of the controls but not statistically significant (P=0.053). There was no correlation between age, sex, and the hair Se levels. In this study, we found that hair Se levels of the children with leukemia and lymphoma, especially those of malnourished patients, were lower than those of controls. Additional studies are needed to determinate whether low levels of hair Se may play a role in carcinogenesis.

Does vitamin A prevent high-dose-methotrexate-induced D-xylose malabsorption in children with cancer?

PURPOSE: Our aim was to explore whether vitamin A has protective effect on high-dose-methotrexate (HDMTX)-induced intestinal D-xylose malabsorption in children with leukemia and lymphoma. PATIENTS AND METHODS: We performed a prospective randomized un-blinded study of vitamin A in 35 children with leukemia and lymphoma who were planned to receive HDMTX 3 g/m(2) and 5 g/m(2), respectively. Twenty-two patients (group 1) received a single dose of 180,000 IU a day before HDMTX was given, and 13 (group 2) received only HDMTX. The vitamin A group received the vitamin only once. Oral D-xylose absorption tests before and 7 days after HDMTX were carried out to evaluate intestinal absorption. Retinol-binding protein (RBP) levels prior to therapy were also measured for vitamin A status. RESULTS: Although we observed no difference of HDMTX-induced toxicity, including hematological, dermatological, systemic, and other toxicities, between groups, the D-xylose absorption test was significantly better in-group 1 ( p=0.030). Absorption was decreased in five of 22 patients (23%) who received vitamin A comparing to eight of 13 (62%) who received only HDMTX ( p=0.033). RBP levels were lower than normal in 13 of 22 patients in-group 1 and nine of 13 in group 2. In patients whose RBP levels were lower than normal, HDMTX-induced toxicity was lower in the group 1 than group 2 but not statistically significant. No sign of vitamin A toxicity was observed throughout the study. CONCLUSION: The administration of vitamin A before HDMTX may protect against drug-induced D-xylose malabsorption in children with cancer. Further studies are apparently needed to clarify the full benefits of vitamin A in preventing HDMTX-induced mucosal damage.