Outcomes of Zoledronic Acid Use in Paediatric Conditions

The Late Effects of Hematopoietic Stem Cell Transplants in Pediatric Patients: A 25-Year Review

CONTEXT

A rare, large, single-center study covering all long-term health outcomes of pediatric allogeneic hemopoietic stem cell transplant (HSCT) survivors, to provide comprehensive local data and identify gaps and future directions for improved care.

OBJECTIVE

To document endocrine sequelae and other late effects of all HSCT recipients.

DESIGN

Retrospective review.

SETTING

Royal Children's Hospital Melbourne.

PATIENTS

384 children and adolescents received HSCT; 228 formed the study cohort; 212 were alive at commencement of data accrual.

INTERVENTION

None.

MAIN OUTCOME MEASURES

Incidence of endocrinopathies; fertility, growth, bone and metabolic status; subsequent malignant neoplasms (SMNs).

RESULTS

Gonadotoxicity was more common in females (P < .001). Total body irradiation (TBI) conditioning was more toxic than chemotherapy alone. All females receiving TBI or higher cyclophosphamide equivalent doses developed premature ovarian insufficiency. In males, impaired spermatogenesis +/- testicular endocrine dysfunction was associated with increasing testicular radiation exposure. Preservation of gonadal function was associated with younger age at HSCT. Of sexually active females, 22% reported spontaneous pregnancies. Short stature was common, with GH axis disruption in 30% of these. Of patients exposed to thyroid radiation, 51% developed nodules; 30% were malignant. Metabolic disturbances included hypertension and dyslipidemias, with both excess and underweight reported. Fragility fractures occurred in 6% and avascular necrosis in 6%. Thirteen percent developed SMNs, with the risk continuing to rise throughout follow-up.

CONCLUSION

We confirm gonadal dysfunction, multiple endocrine and metabolic abnormalities, thyroid cancer, and SMNs as common sequelae of HSCT and identify gaps in management-particularly the need for informed fertility counseling and pretreatment fertility preservation, evaluation, and management of bone health-and underline the need for early lifestyle modification, long-term surveillance, and prospective planned studies aimed at reducing complication risk.

A Review on the Molecular Mechanisms of Action of Natural Products in Preventing Bone Diseases

The drugs used for treating bone diseases (BDs), at present, elicit hazardous side effects that include certain types of cancers and strokes, hence the ongoing quest for the discovery of alternatives with little or no side effects. Natural products (NPs), mainly of plant origin, have shown compelling promise in the treatments of BDs, with little or no side effects. However, the paucity in knowledge of the mechanisms behind their activities on bone remodeling has remained a hindrance to NPs’ adoption. This review discusses the pathological development of some BDs, the NP-targeted components, and the actions exerted on bone remodeling signaling pathways (e.g., Receptor Activator of Nuclear Factor κ B-ligand (RANKL)/monocyte/macrophage colony-stimulating factor (M-CSF)/osteoprotegerin (OPG), mitogen-activated protein kinase (MAPK)s/c-Jun N-terminal kinase (JNK)/nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), Kelch-like ECH-associated protein 1 (Keap-1)/nuclear factor erythroid 2–related factor 2 (Nrf2)/Heme Oxygenase-1 (HO-1), Bone Morphogenetic Protein 2 (BMP2)-Wnt/β-catenin, PhosphatidylInositol 3-Kinase (PI3K)/protein kinase B (Akt)/Glycogen Synthase Kinase 3 Beta (GSK3β), and other signaling pathways). Although majority of the studies on the osteoprotective properties of NPs against BDs were conducted ex vivo and mostly on animals, the use of NPs for treating human BDs and the prospects for future development remain promising.

Drug Treatment of Low Bone Mass and Other Bone Conditions in Pediatric Patients

Osteoporosis may affect young individuals, albeit infrequently. In childhood, bone mass increases, reaching its peak between the second and third decades; then, after a period of stability, it gradually declines. Several conditions, including genetic disorders, chronic diseases, and some medications, can have an impact on bone homeostasis. Diagnosis in young patients is based on the criteria defined by the International Society for Clinical Densitometry (ISCD), published in 2013. High risk factors should be identified and monitored. Often simple interventions aimed to eliminate the underlying cause, to minimize the negative bone effects linked to drugs, or to increase calcium and vitamin D intake can protect bone mass. However, in selected cases, pharmacological treatment should be considered. Bisphosphonates remain the main therapeutic agent for children with significant skeletal fragility and are also useful in a large number of other bone conditions. Denosumab, an anti-RANKL antibody, could become a potential alternative treatment. Clinical trials to evaluate the long-term effects and safety of denosumab in children are ongoing.