Severe non-infective systemic inflammatory response syndrome, shock, and end-organ dysfunction after zoledronic acid administration in a child

A quality improvement project to address the challenges surrounding zoledronic acid use in children

INTRODUCTION

Zoledronic acid (ZA) is an intravenous bisphosphonate used to treat pediatric osteoporosis. Adverse events including hypocalcemia and acute phase reaction (APR) are common following first-infusion. The purpose of this report is to describe implementation of a ZA clinical practice guideline and the subsequent process changes to improve adherence to aspects of the protocol related to safety and efficacy.

METHODS

Quality assurance was evaluated by chart review over a 5-year period to compare the prevalence of hypocalcemia and APR to published data. A quality improvement (QI) initiative consisting of process changes including the addition of an endocrine RN to coordinate infusions and a shift to patient/family self-scheduling of infusions was conducted. The effect of the interventions on safety (completion of pre- and post-infusion bloodwork) and efficacy (receipt of all prescribed infusions) outcomes was evaluated.

RESULTS

Seventy-two patients received 244 infusions over the period. The frequency of hypocalcemia (22%) and APR (31%) was consistent with prior reports. 99% of patients received pre-infusion bloodwork, 78% received post-first-infusion bloodwork, and 47% received all prescribed infusions. QI initiatives increased the percentage of patients receiving post-first-infusion bloodwork from 67 to 79% and those receiving all infusions from 62 to 74%, but fell short of the goal of 90%.

CONCLUSIONS

The implementation of a standardized protocol for ZA use in children was successful in confirming patient eligibility with pre-infusion bloodwork but failed to ensure that patients obtained post-first-infusion bloodwork and received all prescribed infusions. Further efforts to systematize the management of children on ZA are needed.

Acute Respiratory Distress Syndrome Induced by Parathyroid Storm

Hypercalcemic crisis associated with the development of acute respiratory distress syndrome (ARDS) has been rarely documented in the literature. Most cases have been described in patients suffering from malignancies or renal failure with the presence of metastatic calcifications being a prominent feature. Only three cases of ARDS have been reported to date in patients with hypercalcemic crisis due to primary hyperparathyroidism (PHPT). Herein, we report a 72-year-old patient with PHPT that presented with severe hypercalcemic crisis and developed ARDS. He had mild chronic kidney disease and at presentation he had extremely high levels of serum calcium (22.5 mg/dl) and parathormone (3822 pg/ml). After receiving medical treatment for hypercalcemia and the initiation of hemodialysis, he developed ARDS with a fatal outcome, without the presence of pancreatitis, sepsis or heart failure. Although very rare, ARDS should be taken into account as a possible complication of parathyroid crisis, especially in patients with excessive calcium and parathormone levels.

Augmentation of Lipopolysaccharide-Induced Production of IL-1α and IL-1β in Mice Given Intravenous Zoledronate (a Nitrogen-Containing Bisphosphonate) and Its Prevention by Clodronate (a Non-nitrogen-containing Bisphosphonate)

Bisphosphonates (BPs) bind strongly to bone and exhibit long-acting anti-bone-resorptive effects. Among BPs, nitrogen-containing BPs (N-BPs) have far stronger anti-bone-resorptive effects than non-N-BPs. However, N-BPs induce acute inflammatory reactions (fever, arthralgia and myalgia, etc.) after their first injection. The mechanisms underlying these side effects remain unclear. Zoledronate (one of the most potent N-BPs) is given intravenously to patients, and the side-effect incidence is reportedly the highest among N-BPs. Our murine experiments have clarified that (a) intraperitoneally injected N-BPs induce various inflammatory reactions, including a production of interleukin-1 (IL-1) (a typical inflammatory cytokine), and these inflammatory reactions are weak in IL-1-deficient mice, (b) subcutaneously injected N-BPs induce inflammation/necrosis at the injection site, (c) lipopolysaccharide (LPS; a cell-wall component of Gram-negative bacteria) and N-BPs mutually augment their inflammatory/necrotic effects, (d) the non-N-BP clodronate can reduce N-BPs' inflammatory/necrotic effects. However, there are few animal studies on the side effects of intravenously injected N-BPs. Here, we found in mice that (i) intravenous zoledronate exhibited weaker inflammatory effects than intraperitoneal zoledronate, (ii) in mice given intravenous zoledronate, LPS-induced production of IL-1α and IL-1β was augmented in various tissues, including bone, resulting in them increasing in serum, and (iii) clodronate (given together with zoledronate) prevented such augmentation and enhanced, slightly but significantly, zoledronate's anti-bone-resorptive effect. These results suggest that infection may be a factor promoting the acute inflammatory side effects of N-BPs via augmented production of IL-1 in various tissues (including bone), and that clodronate may be useful to reduce or prevent such side effects.

Annual Injection of Zoledronic Acid Improves Bone Status in Children with Cerebral Palsy and Rett Syndrome

Osteoporosis is a common complication of cerebral palsy and Rett's syndrome. It is responsible for multiple fractures, bone pain, and impaired quality of life. In case of Rett's syndrome, a specific dysfunction of osteoblasts causes bone fragility. We observed the effects of annual zoledronic acid (ZA) infusion in a cohort of children with cerebral palsy and Rett's syndrome. 27 children under 18 years (19 with cerebral palsy and 8 girls with Rett syndrome confirmed by MCEP2 mutation) were treated with an annual injection of 0.1 mg/kg (max 4 mg) of ZA. Calcium and vitamin D were combined in all patients from the first injection of ZA. Dental examination was performed before treatment. Data were analyzed retrospectively. Bone mineral density was measured at diagnosis and yearly thereafter. Bone mass density (BMD) is decreased in patient with cerebral palsy and RS. One year after injection of ZA, we observe an increase of Lumbar spine BMD from - 2.99 to - 2.14 SD (p < 0.0001) and femoral BMD from - 4.26 to - 3.32 SD (p < 0.001) In the subgroup of patient with Rett syndrome, we also observe an increase from - 3.27 to 2.50 SD (p = 0.018) of Lumbar spine BMD. No fractures have been observed in our cohort since the first infusion. Side effects (flu-like syndrome and hypocalcemia) were more common in younger patients and after the first infusion. No serious complications were noticed. This study confirms the efficacy and the safety of an annual injection of ZA to improve bone status in children with cerebral palsy and Rett syndrome. No severe adverse effects were observed.

Zoledronic acid in pediatric metabolic bone disorders

Zoledronic acid (ZA), a highly potent intravenous bisphosphonate (BP), has been increasingly used in children with primary and secondary osteoporosis due to its convenience of shorter infusion time and less frequent dosing compared to pamidronate. Many studies have also demonstrated beneficial effects of ZA in other conditions such as hypercalcemia of malignancy, fibrous dysplasia (FD), chemotherapy-related osteonecrosis (ON) and metastatic bone disease. This review summarizes pharmacologic properties, mechanism of action, dosing regimen, and therapeutic outcomes of ZA in a variety of metabolic bone disorders in children. Several potential novel uses of ZA are also discussed. Safety concerns and adverse effects are also highlighted.

Osteogenesis imperfecta in children and adolescents-new developments in diagnosis and treatment

Osteogenesis imperfecta (OI) is the most prevalent heritable bone fragility disorder in children. It has been known for three decades that the majority of individuals with OI have mutations in COL1A1 or COL1A2, the two genes coding for collagen type I alpha chains, but in the past 10 years defects in at least 17 other genes have been linked to OI. Almost all individuals with a typical OI phenotype have a mutation in one of the currently known genes. Regarding medical treatment, intravenous bisphosphonate therapy is the most widely used medical approach. This has a marked effect on vertebra in growing children and can lead to vertebral reshaping after compression fractures, but there is little effect of bisphosphonate therapy on the development of scoliosis. Bisphosphonate treatment decreases long-bone fracture rates, but such fractures are still frequent. Newer medications with anti-resorptive and bone anabolic action are being investigated in an attempt to improve on the efficacy of bisphosphonates but the safety and efficacy of these new approaches in children with OI is not yet established.