Analysis of calcifications in patients with coral reef aorta.
BACKGROUND
Coral reef aorta is a rare vascular disease with intraluminal calcifications of the dorsal part of the visceral aorta. The pathogenesis of this disease with its topographic and morphologic characteristics is unknown. The aim of our study was to investigate calcification inhibitors and the ultrastructure of calcifications in patients with coral reef aorta.


METHODS
Ten patients with coral reef aorta were examined. Calcified specimens were investigated by immunohistochemical techniques for the expression of the calcification inhibitors matrix gla protein (MGP) and fetuin-A. Vessel walls were also assessed by electron microscopic techniques including electron energy-lost spectroscopy, electron dispersive spectroscopy, and electron diffraction. Sera of patients were analyzed for fetuin-A, uncarboxylated MGP (ucMGP), and osteoprotegerin.


RESULTS
As assessed by immunohistochemistry, most MGP was detected in the vicinity of calcified regions. Serum levels of the calcification inhibitors ucMGP, fetuin-A, and osteoprotegerin were 370+/-107 nmol/L, 0.57+/-0.03 g/L, and 5.64+/-0.79 pmol/L, respectively. Ultrastructural analysis of calcified specimens showed a core-shell structure with multiple calcification nuclei. Calcifications displayed a fine-crystalline character, and elemental analysis revealed hydroxyl apatite as the chemical compound.


CONCLUSIONS
The coral reef aorta represents an extreme exophytic growth of vascular calcification with multiple nuclei which resemble typical media calcification. Positive vascular immunostaining and low serum levels of both fetuin-A and ucMGP suggest a pathophysiologic role of these calcification inhibitors in the development of coral reef aorta.
Department of Nephrology and Clinical Immunology, RWTH University Hospital, and Central Facility for Electron Microscopy, RWTH University, Aachen, Germany. gschlieper@ukaachen.de
Georg
G
Schlieper
Dirk
D
Grotemeyer
Anke
A
Aretz
Leon J
LJ
Schurgers
Thilo
T
Krüger
Hermann
H
Rehbein
Thomas E
TE
Weirich
Ralf
R
Westenfeld
Vincent M
VM
Brandenburg
Frank
F
Eitner
Joachim
J
Mayer
Jürgen
J
Floege
Wilhelm
W
Sandmann
Markus
M
Ketteler
D000328:Adult; D000368:Aged; D001011:Aorta / Q000737:chemistry* / Q000473:pathology* / Q000648:ultrastructure; D001018:Aortic Diseases / Q000097:blood / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D001027:Aortography / Q000379:methods; D015415:Biomarkers / Q000032:analysis / Q000097:blood; D001798:Blood Proteins / Q000032:analysis* / Q000378:metabolism; D002114:Calcinosis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology; D002135:Calcium-Binding Proteins / Q000032:analysis* / Q000097:blood; D017886:Durapatite / Q000032:analysis; D016326:Extracellular Matrix Proteins / Q000032:analysis* / Q000097:blood; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D053244:Osteoprotegerin / Q000097:blood; D011446:Prospective Studies; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D060749:alpha-2-HS-Glycoprotein; D000097568:Matrix Gla Protein
D015415:Biomarkers; D001798:Blood Proteins; D002135:Calcium-Binding Proteins; D017886:Durapatite; D016326:Extracellular Matrix Proteins; D053244:Osteoprotegerin; D060749:alpha-2-HS-Glycoprotein; D000097568:Matrix Gla Protein; C556354:AHSG protein, human; C506030:TNFRSF11B protein, human