Circulating forms of ICAM-3 (cICAM-3). Elevated levels in autoimmune diseases and lack of association with cICAM-1.
The intercellular adhesion molecule-3 (ICAM-3) has been identified as the third LFA-1 ligand in addition to ICAM-1 and ICAM-2. In this report we have identified circulating forms of ICAM-3 (cICAM-3) in human serum. Using a sandwich ELISA with two monoclonal anti-ICAM-3 Abs, we detected cICAM-3 in concentrations between 40 and 360 ng/ml in all of 112 healthy controls. An analysis of patient sera from 10 different immune-mediated diseases revealed a distinct pattern of expression. Significantly elevated cICAM-3 levels were found in rheumatoid arthritis, systemic lupus erythematosus, Guillain-Barré syndrome, and multiple sclerosis, but not in type I diabetes, Grave's disease, chronic autoimmune thyroiditis, ulcerative colitis, or Crohn's disease. cICAM-3 levels were significantly higher in systemic lupus erythematosus patients with active compared with nonactive disease. Despite their binding to the same integrin receptor, serum levels of cICAM-3 did not correlate with cICAM-1 concentrations in either normal persons or in patients. The majority of patients had either elevated cICAM-3 or cICAM-1 levels but not both. In conclusion, a circulating form of ICAM-3 is present in human sera. cICAM-3 expression is elevated in certain immune-mediated diseases but occurs independently of cICAM-1.
Martin
S
S
Diabetes Research Institute, Heinrich Heine University of Düsseldorf, Germany.
Rieckmann
P
P
Melchers
I
I
Wagner
R
R
Bertrams
J
J
Voskuyl
A E
AE
Roep
B O
BO
Zielasek
J
J
Heidenthal
E
E
Weichselbraun
I
I
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015703:Antigens, CD; D000943:Antigens, Differentiation; D001327:Autoimmune Diseases / Q000097:blood*; D015815:Cell Adhesion Molecules / Q000097:blood*; D002648:Child; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000097:blood; D008297:Male; D008875:Middle Aged
D015703:Antigens, CD; D000943:Antigens, Differentiation; D015815:Cell Adhesion Molecules; C483616:ICAM3 protein, human; D018799:Intercellular Adhesion Molecule-1