The soluble forms of CD28, CD86 and CTLA-4 constitute possible immunological markers in patients with abdominal aortic aneurysm.
OBJECTIVE
The T cell co-stimulatory factors CD28 and CTLA-4 and their ligands CD80 and CD86 occur as receptors on T cells and antigen-presenting cells and also in soluble forms in the circulation. We determined the levels of soluble co-stimulatory molecules in patients with abdominal aortic aneurysm (AAA) and normal individuals. We further correlated these soluble co-stimulatory molecules to other clinical parameters of importance such as age of the patient, presence of hypertension, size of the aneurysm and levels of matrix metalloproteinases-9 and C-reactive protein.


METHODS
This case-control study was designed to quantify the circulating levels of soluble co-stimulatory molecules by an in-house enzyme linked immunosorbent assay. A total of 314 subjects participated in the study including 100 patients and 214 normal controls. The statistical analysis was performed by Mann-Whitney test and Spearman's correlation rank test.


RESULTS
Our results show increased plasma levels of sCD28, sCD86 (P = 0.0001) and decreased plasma levels of sCTLA-4 (P = 0.0018) in the patients compared with normal individuals. The levels of these factors were not related to the age of the patient, size of aneurysm or levels of C-reactive protein in plasma. There was, however, a significant inverse relationship between the concentrations of sCTLA-4 and sCD80 with matrix metalloproteinase-9.


CONCLUSIONS
We suggest that soluble co-stimulatory molecules serve as biomarkers for the estimation of immune activation in AAA patients.
Sakthivel
P
P
Immunological Research Laboratory, Center for Molecular Medicine (L8:00), Karolinska Hospital, Stockholm, Sweden.
Shively
V
V
Kakoulidou
M
M
Pearce
W
W
Lefvert
A K
AK
D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000097:blood*; D000943:Antigens, Differentiation / Q000097:blood*; D017544:Aortic Aneurysm, Abdominal / Q000097:blood / Q000175:diagnosis / Q000276:immunology*; D051940:B7-2 Antigen / Q000097:blood*; D015415:Biomarkers / Q000097:blood*; D018106:CD28 Antigens / Q000097:blood*; D060908:CTLA-4 Antigen; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged
D015703:Antigens, CD; D000943:Antigens, Differentiation; D051940:B7-2 Antigen; D015415:Biomarkers; D018106:CD28 Antigens; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human