Lymphocyte proliferation in uremic patients: correlation with zinc status

The pivotal role of zinc in the immune response has been well demonstrated in animals with normal renal function; however, there are fewer studies in uremic patients. Twenty uremic patients on regular hemodialysis (HD), and 20 patients on continuous ambulatory peritoneal dialysis (CAPD) were studied for their lymphoproliferative response to concanavalin A, phytohemagglutinin and pokeweed mitogen. CAPD patients had significantly lower levels of plasma zinc (65.8 micrograms/dL vs 75.1 micrograms/dL, p < 0.05) and serum albumin (3.5 g/dL vs 4.4 g/dL, p < 0.05) than HD patients. However, the stimulation indices were similar between these two groups no matter what mitogens were used, although they were significantly lower than those for the normal control group. Regression analysis revealed that there was no correlation between zinc status and the stimulation indices. However, there was a significant correlation between serum zinc and the absolute counts in HD patients. These findings suggest that zinc does not play a consistent role in the impaired lymphoproliferative response among uremic patients receiving different modes of dialysis therapy.