BACKGROUND: The most serious complication of subcutaneous fat necrosis (SCFN), a rare condition of the newborn characterized by indurated purple nodules, is hypercalcaemia. However, the mechanism for this hypercalcaemia remains unclear. OBJECTIVES: To determine whether the hypercalcaemia associated with SCFN involves expression of the vitamin D-activating enzyme 25-hydroxyvitamin D(3)-1alpha-hydroxylase (1alpha-hydroxylase) in affected tissue. METHODS: Skin biopsies from two male patients with SCFN and hypercalcaemia were taken. The histological specimens were assessed using a polyclonal antibody against 1alpha-hydroxylase. RESULTS: Histology in both cases showed strong expression of 1alpha-hydroxylase protein (brown staining) within the inflammatory infiltrate associated with SCFN. This was consistent with similar experiments in other granulomatous conditions. CONCLUSIONS: Hypercalcaemia in SCFN appears to be due to abundant levels of 1alpha-hydroxylase in immune infiltrates associated with tissue lesions. This is consistent with previous observations of extrarenal 1alpha-hydroxylase in skin from other granulomatous conditions such as sarcoidosis and slack skin disease.
BACKGROUND: The most serious complication of subcutaneous fat necrosis (SCFN), a rare condition of the newborn characterized by indurated purple nodules, is hypercalcaemia. However, the mechanism for this hypercalcaemia remains unclear. OBJECTIVES: To determine whether the hypercalcaemia associated with SCFN involves expression of the vitamin D-activating enzyme 25-hydroxyvitamin D(3)-1alpha-hydroxylase (1alpha-hydroxylase) in affected tissue. METHODS: Skin biopsies from two male patients with SCFN and hypercalcaemia were taken. The histological specimens were assessed using a polyclonal antibody against 1alpha-hydroxylase. RESULTS: Histology in both cases showed strong expression of 1alpha-hydroxylase protein (brown staining) within the inflammatory infiltrate associated with SCFN. This was consistent with similar experiments in other granulomatous conditions. CONCLUSIONS:Hypercalcaemia in SCFN appears to be due to abundant levels of 1alpha-hydroxylase in immune infiltrates associated with tissue lesions. This is consistent with previous observations of extrarenal 1alpha-hydroxylase in skin from other granulomatous conditions such as sarcoidosis and slack skin disease.
Authors: Philip T Liu; Steffen Stenger; Huiying Li; Linda Wenzel; Belinda H Tan; Stephan R Krutzik; Maria Teresa Ochoa; Jürgen Schauber; Kent Wu; Christoph Meinken; Diane L Kamen; Manfred Wagner; Robert Bals; Andreas Steinmeyer; Ulrich Zügel; Richard L Gallo; David Eisenberg; Martin Hewison; Bruce W Hollis; John S Adams; Barry R Bloom; Robert L Modlin Journal: Science Date: 2006-02-23 Impact factor: 47.728
Authors: D Zehnder; R Bland; M C Williams; R W McNinch; A J Howie; P M Stewart; M Hewison Journal: J Clin Endocrinol Metab Date: 2001-02 Impact factor: 5.958
Authors: Helen Karakelides; Jordan L Geller; Arnold L Schroeter; Hong Chen; Philip S Behn; John S Adams; Martin Hewison; Robert A Wermers Journal: J Bone Miner Res Date: 2006-09 Impact factor: 6.741