Prevention of steroid-induced low bone mineral density in children with renal diseases: a systematic review

Bone densitometry in children with idiopathic nephrotic syndrome on prolonged steroid therapy: A tertiary multicenter study

Long-term glucocorticoids administration inhibits bone mineralization and has a negative impact on basic cellular mechanisms that are critical in the development and maintenance of bone strength. Steroids can cause osteoporosis in children and have a negative impact on bone mineral content (BMC) and bone mineral density (BMD). We aim to determine the BMD of children with idiopathic nephrotic syndrome (INS) who are on corticosteroids therapy. This cross-sectional study included 90 patients on corticosteroids therapy and 50 apparently healthy age and sex-matched children served as a control group. Renal functions, bone biochemistry, and parathyroid hormone (PTH) were measured in patients and controls. BMD was measured at the lumbar spinal region (L2-L4) using Dual-energy X-ray absorptiometry (DEXA) scan in both patients and controls groups. Serum PTH, phosphorous, and alkaline phosphatase levels were significantly higher in patients than in controls. There was a statistically significant reduction in blood calcium levels in patients compared to controls. Osteopenia was diagnosed by DEXA scan in 24 patients (26.7%) and osteoporosis in 12 patients (13.3 %). There was a statistically significant decline in BMD-z score, BMD, and BMC in patients compared to the healthy group. Patients with INS on corticosteroids treatment have a lower BMD than their peers. Pediatric INS patients had a high prevalence of osteopenia and osteoporosis as measured by DEXA. Steroid therapy has a deleterious impact on bone mineralization in children with INS.

The Italian Society for Pediatric Nephrology (SINePe) consensus document on the management of nephrotic syndrome in children: Part I - Diagnosis and treatment of the first episode and the first relapse

This consensus document is aimed at providing an updated, multidisciplinary overview on the diagnosis and treatment of pediatric nephrotic syndrome (NS) at first presentation. It is the first consensus document of its kind to be produced by all the pediatric nephrology centres in Italy, in line with what is already present in other countries such as France, Germany and the USA. It is based on the current knowledge surrounding the symptomatic and steroid treatment of NS, with a view to providing the basis for a separate consensus document on the treatment of relapses. NS is one of the most common pediatric glomerular diseases, with an incidence of around 2-7 cases per 100000 children per year. Corticosteroids are the mainstay of treatment, but the optimal therapeutic regimen for managing childhood idiopathic NS is still under debate. In Italy, shared treatment guidelines were lacking and, consequently, the choice of steroid regimen was based on the clinical expertise of each individual unit. On the basis of the 2015 Cochrane systematic review, KDIGO Guidelines and more recent data from the literature, this working group, with the contribution of all the pediatric nephrology centres in Italy and on the behalf of the Italian Society of Pediatric Nephrology, has produced a shared steroid protocol that will be useful for National Health System hospitals and pediatricians. Investigations at initial presentation and the principal causes of NS to be screened are suggested. In the early phase of the disease, symptomatic treatment is also important as many severe complications can occur which are either directly related to the pathophysiology of the underlying NS or to the steroid treatment itself. To date, very few studies have been published on the prophylaxis and treatment of these early complications, while recommendations are either lacking or conflicting. This consensus provides indications for the prevention, early recognition and treatment of these complications (management of edema and hypovolemia, therapy and prophylaxis of infections and thromboembolic events). Finally, recommendations about the clinical definition of steroid resistance and its initial diagnostic management, as well as indications for renal biopsy are provided.

Low serum 25-hydroxyvitamin D levels and secondary hyperparathyroidism in Fontan patients

BACKGROUND

Limited data exist on the vitamin D status in Fontan patients. We determined the prevalence and potential risk factors of vitamin D deficiency in this patient subset. Methods and results Data were collected from 27 Fontan patients (55.6% male, mean age 8.1±5.3 years). Protein-losing enteropathy was diagnosed in six patients (22.2%). Vitamin D deficiency was defined as a serum 25-hydroxyvitamin D level of <20 ng/ml. The neutrophil-to-lymphocyte ratio, a marker of systemic inflammation, was calculated. Associations between laboratory measurements and patient characteristics were explored. Mean serum 25-hydroxyvitamin D level was 14.1±10.4 ng/ml. Vitamin D deficiency was found in 19/27 patients (70.3%). Only skin type was associated with vitamin D deficiency (p=0.04). Hyperparathyroidism was present in 5/21 (23.8%) patients, and was more prevalent in patients with protein-losing enteropathy (p<0.001). Parathyroid hormone levels correlated with parameters of systemic inflammation (neutrophil-to-lymphocyte ratio: r=0.484, p=0.026; relative lymphocyte count: r=-0.635, p=0.002). Vitamin D supplementation significantly increased serum 25-hydroxyvitamin D levels (p<0.0001), and was accompanied by a reduction in parathyroid hormone concentrations (p=0.032).

CONCLUSIONS

A high prevalence of vitamin D deficiency was found among Fontan patients, independent of age, time after Fontan procedure, ventricular morphology, and presence of protein-losing enteropathy. A potentially important link between parathyroid hormone levels and systemic inflammation is suggested.

The use of bisphosphonates in pediatrics

Bisphosphonates are widely used for the prevention and treatment of osteoporosis in adulthood. In the last years, bisphosphonates have been increasingly used in pediatric patients for the treatment of a growing number of disorders associated with osteoporosis, resistant hypercalcemia or heterotopic calcifications. The use of bisphosphonates in pediatric patients has been proven safe; however, the risk of potential severe consequences into adulthood should be kept in mind. Well-defined criteria for bisphosphonates treatment in pediatric patients are not specified, therefore an accurate selection of patients who could benefit from bisphosphonates is mandatory. A strict follow-up of pediatric patients receiving long-term bisphosphonate therapy is strongly recommended. The purpose of this mini review is to provide a summary of current knowledge on some main general aspects of the structure, mechanisms of action, pharmacokinetics, and bioavailability of bisphosphonates, and to focus on the latest advances of bisphosphonate treatment in pediatric patients. Particular attention has been paid to the common and potential adverse effects of bisphosphonate treatment, and some suggestions concerning the clinical approach and general measures for bisphosphonate treatment in pediatric patients are reported.