Effect of zinc supplementation on incidence of infections and hospital admissions in sickle cell disease (SCD)

Zinc deficiency is a common nutritional problem in adult sickle-cell diseas e (SCD) patients, Hyperzincuria and increased requirement of zinc due to co ntinued hemolysis in SCD are probable bases for zinc deficiency in these pa tients. Zinc deficiency affects adversely T-helper(1) (TH1) functions and c ell mediated immunity and interleukin (IL)-2 production is decreased in zin c deficient subjects. We hypothesized that zinc supplementation will improv e T-helper, function and decrease incidence of infections in patients with SCD. We tested this hypothesis in 32 SCD subjects who were divided in three groups (Grs A, B, and C). Grs A (n = 11)and B (n = 10)were zinc deficient based on cellular zinc criteria and Gr C (n = 11) were zinc sufficient. Gr A subjects were observed for 1 year (baseline), following which they receiv ed zinc acetate (50 to 75 mg of elemental zinc orally daily) for 3 years. G r B subjects were observed for 1 year(baseline), following which they recei ved placebo for 1 year and then switched to zinc supplementation (50 to 75 mg of elemental zinc orally daily) for 2 years. Gr C subjects did not recei ve any intervention inasmuch as they were zinc sufficient. Prolonged zinc s upplementation resulted in an increase in lymphocyte and granulocyte zinc(P = 0.0001), and an increase in interleukin-a production (P = 0.0001), decre ased incidence of documented bacteriologically positive infections (P = 0.0 026), decreased number of hospitalizations and decreased number of vaso-occ lusive pain crisis (P = 0.0001). The predominant pathogens isolated were st aphylococci and streptococci involving the respiratory tract and aerobic gr am-negative bacteria, particularly Escherichia coli, involving the urinary tract, Further confirmation of our observations will require prospective st udies of zinc supplementation in a larger number of SCD patients. Am. J. He matol. 61:194-202, 1999. (C) 1999 Wiley-Liss, Inc.