[Novel extracorporeal granulocyte apheresis column inhibits myocardial reperfusion injury: future clinical applications].
OBJECTIVE
Leukocyte infiltration is very important in myocardial ischemia/reperfusion injury. A new extracorporeal circulation therapy using a granulocyte-apheresis column (G-1) has recently been proved to be effective and safe in patients with rheumatoid arthritis and with ulcerative colitis. This study investigated whether this therapy would reduce myocardial ischemia/reperfusion injury.


METHODS
Rabbits were subjected to 30 min ischemia followed by 180 min reperfusion with no treatment (control group: n = 12); or treated with extracorporeal blood circulation (2 ml/min) passing through the G-1 (G-1 group: n = 12), or sham column (sham group: n = 12). Infarct size was determined by tetrazolium staining and expressed as a percentage of the area at risk.


RESULTS
Infarct size in the G-1 group (15.9 +/- 3.4%) was significantly (p < 0.01) smaller than in the control (34.7 +/- 3.9%) and sham (35.2 +/- 4.1%) groups. Granulocyte emigration into the ischemic myocardium assessed by histopathological score was significantly (p < 0.01) less in the G-1 group (0.58 +/- 0.17) than in the sham group (1.42 +/- 0.26). There was a significant (r = 0.78, p < 0.0001) positive correlation between this score and infarct size. Flow cytometry showed alterations in the adhesion molecule expression on granulocytes during the passage through the G-1, but not sham, columns as a low L-selectin and high Mac-1 form, which is associated with the inability to home to the inflamed site.


CONCLUSIONS
Extracorporeal circulation with the G-1 column, a newly-developed clinically applicable therapy, appears to reduce infarct size at least in part by limiting the emigration capacity of granulocytes into the ischemic myocardium.
Kouchi
I
I
Cardiovascular Division, Postgraduate School of Medicine, Kyoto University.
Iwase
T
T
Kashiwagi
N
N
Hiraishi
K
K
Murakami
T
T
D000818:Animals; D005112:Extracorporeal Circulation; D005260:Female; D005434:Flow Cytometry; D006098:Granulocytes / Q000502:physiology*; D007937:Leukapheresis / Q000295:instrumentation / Q000379:methods*; D009203:Myocardial Infarction / Q000473:pathology; D015428:Myocardial Reperfusion Injury / Q000517:prevention & control*; D011817:Rabbits