In vitro labelling of platelets. Experimental study on splenectomized patients with lymphomas using two different incubation media.

Duplicate platelet survival studies, using autologous platelets labelled in vitro with radioactive sodium chromate, were carried out on 5 lymphoma patients who had been splenectomized 14-21 months earlier. In the first experiment plasma was employed as the incubation medium and in the second a Ringer-citrate-dextrose (RCD) solution. The uptake of chromate by the platelets was 2.0 times higher in the RCD as compared to the plasma experiments. An identical pattern for the immediate behaviour of infused labelled platelets was observed in the duplicate studies, and the recovery of platelet-bound radioactivity remained stable at the 90% level during 2 h after infusion. In these experiments the means for platelet mean life span were almost identical, 5.4+/-0.6 and 5.3+/-0.5 days, respectively, and significantly (p less than 0.05) shorter than the mean for a control group consisting of 21 healthy males (6.9+/-0.3 days). It is concluded that RCD and plasma seem to serve equally well as incubation medium at the in vitro labelling of platelets.