Diethylenetriaminopentaacetic acid is unsuitable for long-term preservation of RBCs.
BACKGROUND
The addition of an appropriate metal chelator, such as diethylenetriaminopentaacetic acid (DTPA) to stored blood has been shown to be effective in a short-term (0-12 days) prevention of lipid peroxidation of stored RBCS: However, its long-term effectiveness has not been carefully evaluated.


METHODS
Blood was preserved in simulated blood bank conditions with or without the addition of DTPA for 4 weeks. Aliquots of stored blood were taken weekly from the storage bag and the deformability profile was determined using a custom-built laser viscodiffractometer. Malondialdehyde (MDA), an index of lipid peroxidation, and the extent of vesiculation of the stored blood were quantified concurrently.


RESULTS
It was found that MDA values for DTPA-supplemented blood at the end of a 28-day storage period were significantly elevated compared with the DTPA-free counterpart (23.50 +/- 3.2 vs. 16.10 +/- 2.5 microM; p<0.05). In addition, DTPA-supplemented blood was more susceptible to vesiculation than its DTPA-free counterpart (31.26 +/- 4.1 vs. 10.26 +/- 1.5% of acetyl cholinesterase release, p<0.001). These data are also in accordance with the finding of the deformability profile result, indicating that DTPA-supplemented blood exhibits not only a decrease in deformability index, but also a tendency to shift the profile to a lower osmolality compared with that of controls (a dehydration phenomenon).


CONCLUSIONS
Long-term (0-28 days) preservation of human RBCs with DTPA caused a gradual increase in MDA production, a progressive enhancement of the severity of vesiculation, and an alteration in the deformability profile. Free-radical-mediated oxidative damage is likely to be the culprit for this observed phenomenon. In addition, the direct effect of DTPA on RBC structural integrity must be considered.
Liu
T Z
TZ
Department of Medical Technology, Fooyin Institute of Technology, Kaohsiung Hsien, Taiwan. n8898@ms21.hinet.net
Chiu
D T
DT
Stern
A
A
D001793:Blood Preservation; D004912:Erythrocytes; D006801:Humans; D004369:Pentetic Acid; D013997:Time Factors
D004369:Pentetic Acid