Abstract 2325: Endothelial Progenitor Cells Are Decreased In the Blood And In The Graft Of Heart Transplant Patients With Microvasculopathy
We assessed the relationship between peripheral blood progenitor cells (PCs), their incorporation into allografts and coronary microvascular function in heart transplant (HT) patients.
Methods: PCs were determined by flow cytometry on the basis of the surface expression of CD34, CD133, and KDR antigens: CD34+, CD133+, CD34+CD133+, CD34+KDR+, CD133+KDR+, and CD34+CD133+KDR+. Biopsies at 2 different time points were examined. Immunoistochemistry for stem cells marker c-Kit, endothelial progenitor cells VEGFR-2, and CD34 was performed in serial sections in the all biopsies. Cells positive for each marker was counted in all biopsy area-section and the number obtained was corrected by area-section. Coronary flow velocity in the anterior descending coronary artery was detected at rest and during i.v. adenosine by transthoracic echocardiography. Coronary flow reserve (CFR) was the ratio of hyperaemic diastolic mean velocity (DMV) to resting DMV. CFR < 2 was considered abnormal. CFR was measured in 29 pts (24 M, age at HT 50 ± 12 years) and was abnormal in 6 (group A) and normal in 23 (group B).
Results: CFR was lower in group A (1.5 ± 0.1 vs 3.3 ± 0.8, p < 0.0001). CD34+KDR+, CD133+KDR+, and CD34+CD133+KDR+ cell count were lower in group A (p < 0.05) (Figure⇓). Endothelial progenitor cells VEGFR-2 on biopsies tended to be lower in group A (p < 0.06) and are related with circulating CD133+KDR+, and CD34+CD133+KDR+ (r = 0.752, p = 0.003 and r = 0.513, p = 0.052, respectively).
Conclusion: Endothelial progenitor cells are decreased in the blood and in the graft of HT patients with microvasculopathy. Mobilization and engraftment of PCs in HT may be involved in the pathogenesis of allograft vasculopathy.