[Protection of PNH red blood cells from lysis by transferring GPI-anchored protein vesicles of normal human RBCs in vitro].

OBJECTIVE: To observe the transfer of GPI-anchored protein CD59 from vesicles of normal RBCs to paroxysmal nocturnal hemoglobinuria(PNH) RBCs can correct the susceptibility to complement attack in vitro. METHODS: Vesicles released from normal RBCs under ATP depletion or storage, are rich in CD59. PNH CD59- RBCs were separated by elution from immunoaffinity column bound with monoclonal antibody CD59, and then incubated with normal RBCs vesicles. The content of CD59 in vesicles and RBCs was detected by Western blot and flowcytometric analysis respectively and hemolysis of PNH CD59- RBCs was detected by cobra venom factor hemolysis test. RESULTS: The fluorescence intensity of PNH CD59- RBCs were increased from (1.68 +/- 0.57)% to (58.42 +/- 8.25)% and the hemolysis was significantly decreased from (27.13 +/- 9.69)% to (19.49 +/- 7.61)% after incubation with vesicles prepared from normal donors (P < 0.05), while normal RBCs had no obvious change before and after the same treatment. (P > 0.05). CONCLUSIONS: It seems that CD59 protein molecules could be transfered from normal RBCs vesicles to PNH CD59- RBCs and retaining the complement regulatory function. CD59- RBCs could be rendered less liable to hemolyze during complement attack.