MORPHOLOGICAL ALTERATIONS AND INCREASED RESISTANCE TO HEMOLYSIS IN T-BUTYL HYDROPEROXIDE INCUBATED RBC FROM ELDERLY SUBJECTS

The response of human red blood cells (RBC) to oxidative stress has be en studied with the aim to evaluate any difference in the behavior of cells from young and old subjects. Thus, RBC from 5 young (27 +/- 2 ye ars) and 5 old (80 +/- 5 years) individuals have been treated with the organic peroxide t-butyl hydroperoxide (TBHP). The two groups behaved differently: after 4 hrs of incubation in 0.5 mM TBHP, RBC from young donors showed a higher level of hemolysis; instead, RBC from old indi viduals showed abnormal morphologies, being absent in unstressed RBC, with constriction and budding, which could be identified as poikilocyt osis. The same abnormal forms are found in patients with spectrin muta tion, leading us to hypothesize that TBHP causes damage to the cytoske letal spectrin. This suggests that poikilocytosis might be an early st age of red blood cell hemolysis bacause their presence is associated t o a lower level of hemolysis.