title: Increased in vitro differentiation of fibrocytes from keloid patients is inhibited by serum amyloid P.
abstract: Keloid scarring is a form of fibroproliferative dermal wound healing characterized by growth beyond the confines of the original wound. Fibrocytes, derived from peripheral blood mononuclear cells and inhibited by serum amyloid P (SAP), have been linked to other fibroproliferative diseases. We hypothesized that peripheral blood mononuclear cells of keloid formers have a higher propensity to differentiate into fibrocytes and are more resistant to the effects of SAP. To test this hypothesis, plasma was isolated from peripheral blood samples of keloid (n = 10) and age/sex/race-matched control (n = 10) subjects, and SAP levels were measured by enzyme-linked immunosorbent assay. Equal numbers of peripheral blood mononuclear cells were also isolated from these samples and fibrocytes cultured in serum-free media with increasing concentrations of SAP. No difference in plasma SAP levels was found between keloid and control subjects. In the absence of SAP, keloid patients (n = 7) had almost 20 times more fibrocytes than controls (n = 7) in culture (median: 1,087 cells vs. 60 cells; p < 0.01). SAP inhibited the differentiation of keloid fibrocytes in vitro, although a higher concentration of SAP was needed when compared with controls (20 μg/mL keloid vs. 5 μg/mL control). Fibrocytes may contribute to the pathogenesis of keloids, and SAP has potential as a therapeutic agent in the prevention of these lesions.
authors.affiliation: Bobby R. Alford Department of Otolaryngology-Head & Neck Surgery, Baylor College of Medicine, Houston, TX 77030, USA.
authors.forename: Michelle C
authors.initials: MC
authors.lastname: Naylor
authors.forename: David A
authors.initials: DA
authors.lastname: Lazar
authors.forename: Irving J
authors.initials: IJ
authors.lastname: Zamora
authors.forename: Oren P
authors.initials: OP
authors.lastname: Mushin
authors.forename: Ling
authors.initials: L
authors.lastname: Yu
authors.forename: Anthony E
authors.initials: AE
authors.lastname: Brissett
authors.forename: Oluyinka O
authors.initials: OO
authors.lastname: Olutoye
mesh_terms: D000293:Adolescent; D000328:Adult; D002454:Cell Differentiation; D002478:Cells, Cultured; D004431:Ear, External / Q000473:pathology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005347:Fibroblasts / Q000166:cytology* / Q000187:drug effects; D006801:Humans; D007627:Keloid / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D007963:Leukocytes, Mononuclear / Q000166:cytology* / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D000683:Serum Amyloid P-Component / Q000378:metabolism*; D014945:Wound Healing / Q000187:drug effects; D055815:Young Adult
chemical_list: D000683:Serum Amyloid P-Component