Cardiopulmonary bypass increases coronary IL-8 in diabetic patients without evidence of reperfusion injury.
BACKGROUND
Endothelin-1 (ET-1) has been shown to be a potent agonist for monocyte production of the neutrophil chemotactic cytokine interleukin-8 (IL-8). We have shown that diabetic patients demonstrate elevated coronary ET-1 after coronary artery bypass grafting (CABG). We hypothesized that these same diabetic patients would manifest elevated coronary IL-8 and conjugated diene concentrations (an index of reperfusion injury).


METHODS
Sixteen patients [9 nondiabetics and 7 type II diabetics] underwent nonemergent CABG. The two groups did not differ significantly in preoperative ejection fraction, number of vessels bypassed, or cross-clamp time. Coronary sinus samples were obtained prior to cardioplegic arrest (baseline) and at 1 and 15 min after reperfusion periods A and B (A, reperfusion of native coronaries + LIMA; B, reperfusion of saphenous vein grafts in addition to native coronary system + LIMA). Plasma samples were analyzed for IL-8 (ELISA) and conjugated dienes (spectrophotometry).


RESULTS
Initially after reperfusion, IL-8 in both groups was significantly lower than precardioplegia values. In reperfusion B, only the diabetic group demonstrated a significant increase in IL-8 concentrations at 1 and 15 min compared to nondiabetics. Conjugated diene levels were significantly higher in diabetics at each time point than nondiabetics.


CONCLUSIONS
This study demonstrates an early decrease in IL-8 in both groups, most likely related to depressed production secondary to hypothermia. The subsequent elevation in IL-8 only in the diabetic group was seen without concomitant conjugated diene elevation. While no evidence of reperfusion injury was demonstrated in this time frame, the elevation of IL-8 in diabetics after CABG may contribute to later infiltration and associated oxidative damage.
Nawas
S I
SI
Department of Physiology and Biophysics, University of Illinois at Chicago, USA.
Doherty
J C
JC
Vigneswaran
W T
WT
Fogelson
B G
BG
McMillen
M A
MA
Ferguson
J L
JL
Sharma
A C
AC
Law
W R
WR
D000475:Alkenes / Q000097:blood; D002315:Cardiopulmonary Bypass; D003331:Coronary Vessels; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D016209:Interleukin-8 / Q000097:blood*; D008875:Middle Aged; D015428:Myocardial Reperfusion Injury / Q000097:blood*; D013053:Spectrophotometry
D000475:Alkenes; D016209:Interleukin-8