Abstract
Infection is known to account for 20～30% of the causes of death in hemodialysis (HD) patients in Japan. Peripheral blood mononuclear cells (PBMC) obtained from HD patients were reported to decrease interferon (IFN)-γ mRNA expression stimulated with phytohemagglutinin (PHA). As zinc is involved in the control of immunity through intracellular signal transduction, zinc administration could be expected to promote IFN-γ production from PBMC in HD patients. We administrated zinc (34 mg/day) orally for 16 weeks to 14 HD participants with serum zinc of less than 65 μg/dL, and investigated the changes of IFN-γ production from PBMC stimulated with PHA by measuring the number and mean gray value of spots, which reflect the status of IFN-γ-producing cells, using the images obtained from the positive control in T-SPOT®.TB kit (Oxford Immunotec, Inc.). Serum zinc increased significantly at 5 weeks (p<0.01 vs. baseline) and remained unchanged. Although we found no changes in the number of spots at 4 weeks, a significant decrease was shown at 12 weeks (p<0.05 vs. baseline, 4 weeks). Although we found a significant decrease in the mean gray value of spots at 4 weeks (p<0.05 vs. baseline), we found significant increases at 8 weeks (p<0.05 vs. 4 weeks) and 12 weeks (p<0.01 vs. baseline, 4 weeks, 8 weeks). In 20 HD patients without zinc administration, a decrease of the number and an increase of the mean gray value were observed. Therefore, zinc administration in HD patients for 4 weeks would be expected to promote innate immunity by the increase of IFN-γ production from PBMC, although longer administration might have a risk of decreasing IFN-γ production.
