sICAM-1 correlates with myocardial ICAM-1 expression in dilated cardiomyopathy.
BACKGROUND
Dilated cardiomyopathy (DCM) is etiopathogenically linked to intramyocardial inflammation, which is reflected by ICAM-1 abundance. We investigated whether soluble ICAM-1 (sICAM-1) levels in the sera of DCM patients are associated with intramyocardial ICAM-1 expression.


METHODS
Immunohistochemically detected ICAM-1 expression was quantified semiquantitatively in endomyocardial biopsies from DCM patients (n=45; n=17 females; age: 48+/-15 years) and from n=12 donor hearts (controls) by a human observer (baseline vs. enhanced expression) and quantitatively by a digital image analysis (DIA) system. The DIA-measured qualities were area fraction (AF), surface-volume ratio (SVR) and integral optical density (ID). The sICAM-1 levels of the DCM patients and n=12 healthy volunteers (controls) were measured by ELISA (means of duplicate measurements). Intramyocardial ICAM-1 expression and sICAM-1 levels were compared in these DCM patients.


RESULTS
Of the DCM patients, n=24 (53%) demonstrated statistically higher sICAM-1 levels compared to controls (>198 ng/ml). By semiquantitative and quantitative DIA evaluation, endothelial ICAM-1 abundance was present in n=25 (56%) of the DCM biopsies. sICAM-1 correlated significantly (P<0.001) both with the semiquantitatively assessed and the DIA-measured ICAM-1-AF, the ICAM-1-SVR and the ICAM-1-ID. The positive predictive value of sICAM-1 measurements for intramyocardial ICAM-1 abundance was 96%, and the negative predictive value was 71%, with a receiver operating characteristic area under the curve of 0.93. Furthermore, sICAM-1 levels correlated with intramyocardial T-lymphocytic (CD2+/CD3+) infiltrates (P<0.03).


CONCLUSIONS
Measurement of non-invasively obtained sICAM-1 reliably reflects intramyocardial ICAM-1 expression and may therefore serve as a non-invasive marker of inflammatory activity in DCM.
Noutsias
Michel
M
Department of Cardiology and Pneumonology, University Hospital Benjamin Franklin, Free University of Berlin, Hindenburgdamm 30, D-1200 Berlin, Germany. noutsias@zedat.fu-berlin.de
Hohmann
Claudia
C
Pauschinger
Matthias
M
Schwimmbeck
Peter-Lothar
PL
Ostermann
Karsten
K
Rode
Ullrich
U
Yacoub
Magdi H
MH
Kühl
Uwe
U
Schultheiss
Heinz-Peter
HP
D000328:Adult; D000945:Antigens, Differentiation, T-Lymphocyte / Q000378:metabolism; D001706:Biopsy; D002311:Cardiomyopathy, Dilated / Q000378:metabolism* / Q000503:physiopathology; D004730:Endothelium, Vascular / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D018799:Intercellular Adhesion Molecule-1 / Q000096:biosynthesis*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D012995:Solubility; D013223:Statistics as Topic; D013318:Stroke Volume / Q000502:physiology; D014019:Tissue Donors
D000945:Antigens, Differentiation, T-Lymphocyte; D018799:Intercellular Adhesion Molecule-1