Secretory type II phospholipase A(2) binds to ischemic myocardium during myocardial infarction in humans.
OBJECTIVE
An increase of circulating secretory Phospholipase A(2) (sPLA(2)) is a risk factor for coronary artery disease. We hypothesized that this reflects participation of sPLA(2) in local inflammatory reactions ensuing in ischemic myocardium. Therefore, we studied the course of circulating sPLA(2), in patients with acute myocardial infarction (AMI) or unstable angina pectoris (UAP), and investigated the presence of sPLA(2) in infarcted myocardial tissue.


METHODS
Plasma samples of 107 patients with AMI or UAP, collected on admission and at varying intervals thereafter, were tested for the presence of sPLA(2) and C-reactive protein (CRP). Cumulative release values of these parameters were calculated, which allowed for comparison of the results rearranged in time according to the onset of symptoms. By immunohistochemistry we studied the presence of sPLA(2) and CRP in myocardial tissue of 30 patients who died subsequent to AMI.


RESULTS
Levels of sPLA(2) became elevated during the disease course in 66 of the 87 patients with AMI, and were higher than those of the patients with UAP of whom 8 of the 20 had elevated levels. By immunohistochemistry sPLA(2) was found to be localized in the infarcted myocardium, particularly in its borderzone, from 12 h after the onset of AMI. Positive staining for sPLA(2) was more extensive than that for CRP.


CONCLUSIONS
The localization pattern of sPLA(2) in infarcted myocardium as well as its plasma course, in relation to those of CRP, are in line with a supposed pro-inflammatory role during AMI for sPLA(2) as a generator of lysophospholipids serving as ligands for CRP.
Nijmeijer
Remco
R
Department of Pathology, VU Medical Center Amsterdam, Room No. PA002, De Boelelaan 1117, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands. R.Nijmeijer@VUMC.NL
Lagrand
Wim K
WK
Baidoshvili
Alexi
A
Lubbers
Yvonne T P
YT
Hermens
Wim Th
WT
Meijer
Chris J L M
CJ
Visser
Cees A
CA
Hack
C Erik
CE
Niessen
Hans W M
HW
D000789:Angina, Unstable / Q000201:enzymology; D015415:Biomarkers / Q000032:analysis; D002097:C-Reactive Protein / Q000032:analysis / Q000378:metabolism; D003593:Cytoplasm / Q000737:chemistry; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D009203:Myocardial Infarction / Q000201:enzymology* / Q000378:metabolism; D009206:Myocardium / Q000737:chemistry / Q000201:enzymology*; D010741:Phospholipases A / Q000032:analysis* / Q000097:blood; D011485:Protein Binding; D012044:Regression Analysis; D012508:Sarcolemma / Q000737:chemistry; D013997:Time Factors
D015415:Biomarkers; D002097:C-Reactive Protein; D010741:Phospholipases A