The serum level of 25-hydroxyvitamin D for maximal suppression of parathyroid hormone in children: the relationship between 25-hydroxyvitamin D and parathyroid hormone / 소아과

PURPOSE: Serum level of 25-hydroxyvitamin D (25-OHD) is considered as the most appropriate marker of vitamin D status. However, only a few studies have investigated the relationship between 25-OHD and parathyroid hormone (PTH) in children. To this end, this study was aimed at evaluating the lowest 25-OHD level that suppresses the production of parathyroid hormone in children. METHODS: A retrospective record review was performed for children aged 0.2 to 18 years (n=193; 106 boys and 87 girls) who underwent simultaneous measurements of serum 25-OHD and PTH levels between January 2010 and June 2014. RESULTS: The inflection point of serum 25-OHD level for maximal suppression of PTH was at 18.0 ng/mL (95% confidence interval, 14.3–21.7 ng/mL). The median PTH level of the children with 25-OHD levels of <18.0 ng/mL was higher than that of children with 25-OHD levels ≥ 18.0 ng/mL (P<0.0001). The median calcium level of children with 25-OHD levels<18.0 ng/mL was lower than that of children with 25-OHD levels≥18.0 ng/mL (P=0.0001). The frequency of hyperparathyroidism was higher in the children with 25-OHD levels<18.0 ng/mL than in the children with 25-OHD levels≥18.0 ng/mL (P<0.0001). Hypocalcemia was more prevalent in the children with 25-OHD levels<18.0 ng/mL than in the children with 25-OHD levels≥18.0 ng/mL (P<0.0001). CONCLUSION: These data suggest that a vitamin D level of 18.0 ng/mL could be the criterion for 25-OHD deficiency in children at the inflection point of the maximal suppression of PTH.

Atypical Kawasaki Disease Presenting as Acute Kidney Injury in a Patient with Influenza B Virus Infection / 이화의대지

Influenza virus infection is a common respiratory disease in children. Renal complications of influenza infection were not commonly encountered until the 2009 H1N1 influenza pandemic, when acute kidney injury (AKI) frequently developed in severely ill patients. Kawasaki disease (KD) is another rare association in pandemic influenza virus infections. There are some reports about KD coincident with influenza A H1N1/09 infection. However, simultaneous AKI and KD in influenza A or B virus infections have never been reported. Herein, we report the first case of influenza B virus infection that initially presented as AKI but was subsequently diagnosed as atypical KD.