The effect of cyclosporine-A on labeling blood cells with radiopharmaceuticals.

The effect of cyclosporine-A (CsA) on the labeling efficiencies of red blood cells with reduced 99mTcO4-; leukocytes and platelets with 111In oxine was studied. Blood was used from rats treated with CsA (30 mg/kg body weight) for 28 consecutive days and from control rats. For 99mTc labeling of RBCs, blood was obtained from individual rats and in vitro labeling technique was used. For leukocyte and platelet labeling, blood was pooled from 5 rats either treated with CsA or control. Leukocytes/platelets were labeled with 111In oxine using routine techniques. The labeling efficiency for 99mTc RBCs was 83.42 +/- 0.83% (CsA treated) and 84.85 +/- 0.62% (control); 111In-oxine leukocytes was 38.5 +/- 1.75% (CsA treated) and 42.5 +/- 3.53% (control); and for 111In-oxine platelets, it was 74.0 +/- 2.5% (CsA treated) and 78.0 +/- 1.41% (control). Comparison of the results indicate that there is no difference between the percent labeling efficiencies of 99mTc RBCs, 111In-oxine leukocytes, and 111In-oxine platelets for CsA-treated and control rats. Hence, CsA does not interfere with the labeling process of blood cells with radiopharmaceuticals.