Biodistribution of bone marrow mononuclear cells in chronic chagasic cardiomyopathy after intracoronary injection.

ABSTRACT

BACKGROUND: Animal and human clinical studies have indicated that bone marrow (BM) mononuclear cell (MNC) therapy for Chagasic Cardiomyopathy (ChC) is feasible, safe and potentially efficacious. Nevertheless, little is known about the retention of these cells after intracoronary (IC) infusion. METHODS: Our study investigated the homing of technetium-99m ((99m)Tc) labeled BM MNCs and compared it to thallium-201 ((201)Tl) myocardial perfusion images using the standard 17-segment model. Six patients with congestive heart failure of chagasic etiology were included. RESULTS: Scintigraphic images revealed an uptake of 5.4%±1.7, 4.3%±1.5 and 2.3%±0.6 of the total infused radioactivity in the heart after 1, 3 and 24h, respectively. The remaining activity was distributed mainly to the liver and spleen. Of 102 segments analyzed, homing took place in 36%. Segments with perfusion had greater homing (58.6%) than those with decreased or no perfusion (6.8%), p<0.0001. There was no correlation between the number of injected cells and the number of segments with homing for each patient (r=-0.172, p=0.774). CONCLUSIONS: These results indicate that (99m)Tc-BM MNCs delivered by IC injection homed to the chagasic myocardium. However, cell biodistribution was heterogeneous and limited, being strongly associated with the myocardial perfusion pattern at rest. These initial data suggest that the IC route may present limitations in chagasic patients and that alternative routes of cell administration may be necessary.