EFFECTS OF DIMETHYL SULFOXIDE AND SECOND-MESSENGER EFFECTOR ON CRYOPRESERVED PLATELET MEMBRANE EXPRESSIONS CD42b AND CD62p

Objective To observe the effect of cryopreservation with 0.02 dimethyl sulfoxide(DMSO) plus ThromboSol, a mixture of second-messenger effectors, on platelet membrane CD42b and CD62p, and to investigate the long-term (6 months) preservation effect of the platelet storage solution. Methods Platelet concentrates were treated with 0.02 DMSO, 0.06 DMSO and 0.02 DMSO plus ThromboSol, and then placed in liquid nitrogen. The samples were thawed and expression levels of CD42b and CD62p on platelet membrane were analyzed after one month, three months and six months, respectively. Results The platelet expression level of CD42b in the 0.02 DMSO-plus-ThromboSol group was not significantly different from those in the 0.06 DMSO group (F=3.13-5.01,q=1.12-1.76, P0.05), and the levels of both groups were higher than those in the 0.02 DMSO group (q=3.17-4.06, P0.05) one, three and six months later. The CD42b levels of the three groups were lower than those of the fresh platelets (q=3.09-4.15, P0.05). The platelets treated with 0.02 DMSO plus ThromboSol showed statistically lower CD62p expression than those frozen with 0.06 DMSO and 0.02 DMSO(F=5.75-9.77,q=3.20-4.34,P0.05). There were no obvious differences in CD62p expression between platelets treated with 0.06 DMSO and 0.02 DMSO (q=1.55-2.02, P0.05). But the three groups of frozen platelets showed significant increase of surface expression of CD62p in comparison to the fresh platelets (F=3.95, q=4.85-7.35, P0.01). Conclusion The second-messenger effectors could reduce the DMSO concentration. The 0.02 DMSO plus ThromboSol is superior to 0.06 DMSO in inhibiting the activation of platelets, and is stable within six months.