Abstract:
The effect of pyridoxine (PN) supplementation on lymphocyte
responsiveness was investigated in 15 elderly volunteers (aged
65-81 years) by measuring lymphocyte proliferation to T and B cell
mitogens, lymphocyte subpopulations with monoclonal antibodies
(T3, T4, T8) and plasma pyridoxal 5'-phosphate (PLP) concentration
at pre-supplementation and after 1 and 2 months of daily
supplementation. Eleven subjects received 50mg of PN-HC1 and 4
received a placebo. Dietary histories were also evaluated for
Intake of vitamin B-6, protein and kilocalories. Mitogens used
for the stimulation of lvmphocyte proliferation were phytohemagglutinin (PHA), concanavalln A (Con A), pokeweed mitogen
(PWM), and Staphylococcus aureus Cowain I (SAC). Plasma PLP was
measured by a radio tracer method. Before supplementation, mean
PLP of the 15 subjects was 31.7 +/- 14.1 nM; 5 PN and 3 placebo
treated subjects had low PLP levels. After 1 and 2 months of
PN-HCl supplementation, the PLP levels Increased by 195 +/-88 nM
and 201 +/-84 nM, respectively. Lymphocyte proliferation In
response to PHA, PWM, and SAC Increased significantly (p < 0.05)
with PN supplementation. Among PN-treated subjects, Ivmpbocyte
blaatogenesls was significantly greater In response to Con A and
PWM in individuals whose initial PLP was low. Percentages of T3+
and T4+, but not T8+ cells increased significantly In PN-treated
individuals. These results suggest that vitamin B-6 status is
important in maintaining immunocompetence in the elderly.
