This study aims to evaluate the role of leukocyte activation in coronary artery disease

1. The primary aim of REAL CAD is to determine regional differences of leukocyte activation in different vascular beds in vivo.
2. The secondary aim is to investigate differences in leukocyte activation between diabetic and CAD subjects and patients suffering from both.
3. The third aim is to investigate the relationship between complement components, triglycerides and leukocyte activation markers in order to gain more insight into the causative processes leading to activation of leukocytes.
4. The fourth aim is to get more insight in the MBL genotypes and serum levels of CAD and/or diabetic patients and the 'healthy' groups included in our study.

Inclusion Criteria:

• Subjects scheduled to undergo a coronary catheterization
• Provide written informed consent
• Aged >18 and <75 years
• BMI < 35 kg/m2

Exclusion Criteria:

• Emotionally and intellectually not capable to decide about participation in the study and the consequences of participation. Subjects who are not able to understand the patient information
• CRP > 20 mg/l
• Unstable angina pectoris
• CABG or PTCA during the last 6 months
• Alcohol use > 2 units/day
• Aberrations in kidney, liver and thyroid function
• Use of any experimental medication within 6 months of the catheterization
• The use of immunosuppressive drugs

Patients undergoing coronary angiography