Cutaneous calcification in patients with end-stage renal disease: a regulated process associated with in situ osteopontin expression.
BACKGROUND
Cutaneous calcification, or calcinosis cutis (CC), is found in approximately 1% of patients with end-stage renal disease (ESRD) undergoing chronic dialysis. While the pathogenesis is not well understood, it may be similar to those for medial and intimal vascular calcifications, which are actively regulated processes.


METHODS
In a retrospective study of 9 patients, the role of an active calcification process leading to CC was assessed by the immunohistochemical detection of osteopontin, which is a regulator of osseous and extra-osseous calcification processes. Calcinosis cutis was associated with female sex, vascular comorbidity, inconstant secondary hyperparathyroidism, and elevated levels of plasma calcium-phosphorus product. Six patients had a favorable outcome after the lowering of plasma calcium levels during dialysis or after parathyroidectomy.


CONCLUSIONS
Calcinosis of the vascular media of subcutaneous vessels was the most common histologic feature and was always associated with osteopontin staining, suggesting that CC is a regulated process. Moreover, to our knowledge, extravascular staining of osteopontin in sweat glands, nerves, and macrophages was demonstrated for the first time in this study.
Rivet
Jacqueline
J
Department of Pathology, AP-HP, Saint-Louis Hospital, INSERM U728, Paris, France. jacqueline.rivet@sls.ap-hop-paris.fr
Lebbé
Celeste
C
Urena
Pablo
P
Cordoliani
Florence
F
Martinez
Franck
F
Baglin
Anne C
AC
Aubert
Pierre
P
Aractingi
Selim
S
Ronco
Pierre
P
Fournier
Philippe
P
Janin
Anne
A
D000328:Adult; D000368:Aged; D002114:Calcinosis / Q000453:epidemiology* / Q000209:etiology / Q000378:metabolism / Q000473:pathology; D005260:Female; D005602:France / Q000453:epidemiology; D006801:Humans; D007150:Immunohistochemistry; D007676:Kidney Failure, Chronic / Q000150:complications*; D008297:Male; D008499:Medical Records; D008875:Middle Aged; D053495:Osteopontin; D012189:Retrospective Studies; D012795:Sialoglycoproteins / Q000378:metabolism; D012871:Skin Diseases / Q000453:epidemiology* / Q000209:etiology / Q000378:metabolism / Q000473:pathology
C506895:SPP1 protein, human; D012795:Sialoglycoproteins; D053495:Osteopontin