Increased non-transferrin bound iron in plasma-depleted SAG-M red blood cell units.
OBJECTIVE
Non-transferrin bound iron (NTBI) is associated with increased morbidity in a number of transfusion-dependent disease states such as the severe haemoglobinopathies. We hypothesized that this may be related to excess NTBI present in plasma-depleted red blood cell units that are free of clear haemolysis.


METHODS
The level of NTBI was determined using the bleomycin assay in samples from 20 stored plasma-depleted red cell units, at approximate 5-day intervals up to day 33 after donation. Forty units of fresh-frozen plasma (FFP) and 40 units of platelet concentrates were used as negative controls, and samples from 12 units of FFP were also serially assessed.


RESULTS
Median [interquartile range (IQR)] NTBI was 0 microm (0-0.35) in samples taken from units 3-10 days after donation. Thereafter, the levels of NTBI increased, becoming significant (median 3.05; IQR: 0.05-6.7 microm) 17-22 days after donation. After 30 days, NTBI was detectable in all red cell units. NTBI was undetectable in platelet concentrates and FFP.


CONCLUSIONS
Increased levels of NTBI become detectable 17-22 days after donation and increase further with storage time. This excess NTBI may promote bacterial infection in iron-loaded individuals.
Marwah
S S
SS
The City Hospital NHS Trust, Birmingham, UK. Sukhijinder.Marwah@cityhospbham.wmids.nhs.uk
Blann
A
A
Harrison
P
P
Lumley
M A
MA
Wright
J
J
McDowell
J
J
Phillips
J D
JD
Rea
C
C
Bareford
D
D
D001424:Bacterial Infections; D001793:Blood Preservation / Q000379:methods; D017707:Erythrocyte Transfusion; D004912:Erythrocytes; D006801:Humans; D019190:Iron Overload / Q000150:complications / Q000209:etiology*; D010952:Plasma Substitutes / Q000737:chemistry*; D013997:Time Factors; D014168:Transferrin / Q000502:physiology
D010952:Plasma Substitutes; C051020:SAG-M blood; D014168:Transferrin