Demographic and disease-related factors impact bone turnover and vitamin D in children with hemato-oncological diseases.

Children with hemato-oncological diseases may have significant skeletal morbidity, not only during and after treatment but also at the time of diagnosis before cancer treatment. This study was designed to evaluate the vitamin D status and circulating bone metabolic markers and their determinants in children at the time of diagnostic evaluation for hemato-oncological disease. This cross-sectional study included 165 children (91 males, median age 6.9 yr range 0.2-17.7 yr). Of them, 76 patients were diagnosed with extracranial or intracranial solid tumors, 83 with leukemia, and 6 with bone marrow failure. Bone metabolism was assessed by measuring serum 25OHD, PTH, bone alkaline phosphatase, intact N-terminal propeptide of type I procollagen, and C-terminal cross-linked telopeptide of type I collagen. Vitamin D deficiency was found in 30.9% of children. Lower 25OHD levels were associated with older age, lack of vitamin D supplementation, season outside summer, and a country of parental origin located between latitudes -45° and 45°. Children diagnosed with leukemia had lower levels of markers of bone formation and bone resorption than those who had solid tumors or bone marrow failure. In conclusion, vitamin D deficiency was observed in one-third of children with newly diagnosed cancer. Bone turnover markers were decreased in children with leukemia, possibly because of the suppression of osteoblasts and osteoclasts by leukemic cells. The identification of patients with suboptimal vitamin D status and compromised bone remodeling at cancer diagnosis may aid in the development of supportive treatment to reduce the adverse effects of cancer and its treatment.

The human cathelicidin hCAP-18 in serum of children with haemato-oncological diseases.

The human cathelicidin hCAP-18 (pro-LL-37) is the pro-protein of the antimicrobial peptide LL-37. hCAP-18 can be produced by many different cell types; bone marrow neutrophil precursors are the main source of hCAP-18 in the circulation. Neutrophil count is used as a marker for myelopoiesis but does not always reflect neutrophil production in the bone marrow, and thus additional markers are needed. In this study, we established the reference interval of serum hCAP-18 level in healthy children and compared serum hCAP-18 levels between different diagnostic groups of children with haemato-oncological diseases, at diagnosis. We found that children with diseases that impair myelopoiesis, such as acute leukaemia, aplastic anaemia, or myelodysplastic syndrome, presented with low hCAP-18 levels, whereas patients with non-haematological malignancies displayed serum hCAP-18 levels in the same range as healthy children. Children with chronic myeloid leukaemia presented with high circulating levels of hCAP-18, probably reflecting the high number of all differentiation stages of myeloid cells. We suggest that analysis of serum hCAP-18 provides additional information regarding myelopoiesis in children with haemato-oncological diseases, which may have future implications in assessment of myelopoiesis in clinical management.

Prevalence of and factors influencing vitamin D deficiency in paediatric patients diagnosed with cancer at northern latitudes.

AIM: To investigate the prevalence of vitamin D deficiency among children with non-haematological malignancies and to explore possible causes of low vitamin D levels among these patients. METHODS: We performed a cross-sectional study of 458 children diagnosed with solid tumours, brain tumours, non-Hodgkin lymphoma or Hodgkin disease at the University Children's Hospital, Uppsala, Sweden. Serum 25-hydroxyvitamin D and parathyroid hormone levels were measured in samples taken at the time of cancer diagnosis and related to clinical data. Vitamin D deficiency was defined as a 25-hydroxyvitamin D level below 50 nmol/L. RESULTS: The prevalence rate of vitamin D deficiency among children with non-haematological malignancies was 41%. There was no association between sex or diagnosis and vitamin D status. Vitamin D deficiency was more common among school children than preschool children (51% vs. 24%). Older age, season outside summer, and a more recent calendar year were significant predictors of lower 25-hydroxyvitamin D. There was a significant, albeit weak, negative correlation between 25-hydroxyvitamin D and parathyroid hormone. CONCLUSION: Vitamin D deficiency is common among children diagnosed with cancer, particularly among school-aged children diagnosed outside summer. The prevalence appears to be increasing, underlining the need for adequate replacement of vitamin D in these patients.

Vitamin D status in children with leukemia, its predictors, and association with outcome.

BACKGROUND: Children and adolescents with leukemia are potentially at high risk of vitamin D inadequacy, which may have clinical relevance for skeletal morbidity, infections, and cancer outcome. This study aimed to evaluate vitamin D status at the time of diagnosis to investigate its predictors and association with overall survival in children with leukemia. PROCEDURE: We included all 295 children and adolescents diagnosed with leukemia at our institution between 1990 and 2016 who had available serum sample from the time of diagnosis. We analyzed serum 25-hydroxyvitamin D and parathyroid hormone levels and correlated them with clinical data. RESULTS: The 25-hydroxyvitamin D level was deficient (< 25 nmol/L), insufficient (25-50 nmol/L), sufficient (50-75 nmol/L), and optimal (> 75 nmol/L) in 6.4%, 26.8%, 39.7%, and 27.1% of the children, respectively. Older age and a more recent time of sampling (calendar year) predicted lower 25-hydroxyvitamin D level. In preschool children (age ≤6 years), lower 25-hydroxyvitamin D level was also associated with acute myeloid leukemia, and a 25-hydroxyvitamin D level < 50 nmol/L was associated with inferior overall survival. In school-aged children (age > 6 years), the 25-hydroxyvitamin D level showed significant seasonal variation. CONCLUSION: It remains unclear whether vitamin D supplementation in pediatric leukemia patients will improve outcome.