Relation between pyridoxal and pyridoxal phosphate concentrations in plasma, red cells, and white cells in patients with critical illness
Date
2008-07-01Author
Vasilaki, Katerina
McMillan, Donald C.
Kinsella, John
Duncan, Andrew
O'Reilly, Denis St J.
Talwar, Dinesh
Metadata
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Vasilaki, K., McMillan, D.C., Kinsella, J., Duncan, A., O'Reilly, D.S.J. and Talwar, D. (2009) ‘Relation between pyridoxal and pyridoxal phosphate concentrations in plasma, red cells, and white cells in patients with critical illness’, The American Journal of Clinical Nutrition, 88(1), pp. 140-146.
Abstract
Background: Evidence suggests that the relation between plasma
and red cell vitamin B-6 concentrations is perturbed as part of the
systemic inflammatory response in critically ill patients.
Objective: The aim was to examine the cross-sectional and longitudinal interrelations between pyridoxal (PL) and pyridoxal phosphate (PLP) concentrations in plasma and red and white cells in
patients with critical illness.
Design: PLP and PL concentrations were measured by HPLC in
plasma and red and white cells in normal subjects (n 126) and
critically ill patients (n 96) on admission and on follow-up.
Results: On admission, compared with the controls, median plasma
PLP and PL (P 0.001 and 0.01, respectively) and red cell PLP
and PL (P0.001 and0.05, respectively) andtheir ratio (PLP:PL)
in plasma and red cells (P 0.001 and 0.01, respectively) were
significantly lower in the critically ill. In critically ill patients,
plasma PLP:PL was significantly lower than red cell PLP:PL (P
0.001) and white cell PLP:PL (P 0.008). Plasma PL concentration
was directly associated with both red cell PL (rs 0.73, P 0.001)
and white cell PL (rs 0.68, P 0.001). Red cell PL and white cell
PL were directly associated with red cell PLP (rs 0.82, P 0.001)
and white cell PLP (rs 0.68, P 0.001), respectively. Longitudinal measurements (n 48) were similar.
Conclusions: The relation between plasma PLP and PL was significantly perturbed in critical illness. This effect was less pronounced
in red and white cells. Therefore, these results confirm the hypothesis that intracellular PLP concentrations are more likely to be a
reliable measure of status than are plasma measurements in the
critically ill patient.