Abstract 15464: Serum CXCL12 Levels Decrease Following Acute Myocardial Infarction - Data from the Pakistan Risk of Myocardial Infarction Study (PROMIS)
Introduction: Genome-wide association studies have identified common polymorphisms near the CXCL12 gene that are significantly associated with myocardial infarction (MI). Variants associated with increased risk are associated with higher serum levels of the chemokine CXCL12. Based on our response that serum CXCL12 levels decrease following low-dose experimental endotoxemia in humans, we hypothesized that acute MI would decrease serum CXCL12 levels. We utilized a large MI case-control cohort to examine the association of serum CXCL12 levels with time from onset of chest pain.
Methods: The Pakistan Risk of Myocardial Infarction Study (PROMIS) is a case-control study which enrolled 9,000 MI cases and 9,000 sex and age matched controls from 6 urban centers in Pakistan. We measured CXCL12 levels in serum samples from 150 MI subjects. From each of these subjects, samples were obtained at the time of presentation (within 1 - 10 hours of the onset of chest pain), 12 hours, and 24 hours from the time of presentation. All samples were stored at -70 C at the recruitment center and were transferred on dry ice for laboratory measurements. Serum CXCL12 levels were measured using a commercial ELISA kit (R&D, USA). To analyze the relationship between serum CXCL12 levels and time from the onset of chest pain, generalized estimated equation regression models with fractional polynomial analyses were used in STATA 11.
Results: 80% of the subjects were male and the mean age was 54 years (+/- 10). Intra-assay variability for the ELISA in PROMIS samples was < 5%. Serum CXCL12 levels decreased 9.03% with time from onset of chest symptoms (p < 0.001), suggesting consumption of CXCL12 in the acute MI setting within the first 24 hours.
Conclusions: This is the first study to assess the changes in serum CXCL12 levels following an acute MI. These analyses support a consumption of CXCL12 in an acute MI setting in the first 24 hour following the onset of chest symptoms. These findings have implications for understanding the pathophysiological relationship between CXCL12 and myocardial infarction.
- © 2011 by American Heart Association, Inc.