Surface protein CXCR4
CXCR4 is a surface protein detectable on a variety of cell types that are associated with inflammation in the human body. Applying a CXCR4-targeted PET makes it possible to detect cells that express this protein. Leukocytes including T-lymphocytes express CXCR4. T- lymphocytes are activated by encountering autoantigens released from the injured heart. Prior studies have shown that this activation occurs in the mediastinal lymph nodes and correlates with clinically relevant parameters.
We will analyze whether an association exists between the inflammatory activity as detected by the CXCR4-targeted PET- signal in lymph nodes and infarct region in the heart, and the further clinical course after a myocardial infarction. We hypothesize that the CXCR4 -PET signal from the heart or lymphatic organs might constitute a prognostic marker and might help to identify patients that could benefit from immune-modulatory therapy.
Within the first few days after a myocardial infarction, we will examine patients with MRI and CXCR4-targeted PET focusin on the lymph nodes and the heart. These results will be correlated with blood analyses. During the course of 12 months, the heart function of these patients will be reassessed with cardiac MRI and echocardiography.We will also analyze whether such an early multimodal imaging approach will allow a more exact prediction of the clinical course than established parameters do.
Besides lymph nodes and the heart, other organs involved in the immune response show a CXCR4- targeted PET signal. By using fluorescence- marked CXCR4 molecules, we will analyze the CXCR4-expressing cell types in these organs.
Currently, it is not possible to image the immune response triggered by an acute myocardial infarction in patients. With the help of CXCR4-targeted PET/CT of lymph nodes and the heart it might be possible to non-invasively monitor the immune response to MI and to predict on the further clinical course.
Medizinische Klinik und Poliklinik I, Universitätsklinikum Würzburg, Zentrum für Innere Medizin (ZIM), Oberdürrbacher Straße 6, Haus A3, 97080 Würzburg, Deutschland
Deutsches Zentrum für Herzinsuffizienz Würzburg | Comprehensive Heart Failure Center | Am Schwarzenberg 15 | Haus A15 | 97078 Würzburg