THE RELATIONSHIP OF PLASMA ZINC TO LYMPHOCYTE SUBSETS IN CHILDREN WITH CHRONIC UPPER RESPIRATORY-TRACT INFECTIONS

Plasma zinc level (PZL) and peripheral blood lymphocyte subsets were s imultaneously assessed in children with plasma zinc levels >0.80 mg/L (Group I, 20 cases), and in children with plasma zinc levels <0.70 mg/ L, with chronic upper respiratory infection (Group II, 22 cases) durin g one of the silent periods; and before (Group III-A, 11 cases) and af ter (Group III-B) 2 mg/kg/30 days zinc sulphate supplementation. Among all the significant findings of Student's t-test and regression analy sis, the outstanding significant differences were: 1) between T4T8 rat ios (P < .001, t = 3.469) in Groups I and II; and 2) between T-4/T-8 r atios (P < .013, t = 2.715) in Groups III-A and III-B. Significant pol ynomial parabolic relations were found 1) between Ts counts and the PZ L in Group II (P < .009, r = 0.626) and in Group III-A (P < .039, r = 0.746), respectively; and 2) between B lymphocyte (B lym) populations and the PZL in Group II (P < .002, r = 0.688) and in Group m-A (P < .0 20, r = 0.790) respectively. Significant multifactorial relations were found 1) between PZL-T-8-B lym (P < .007, r = 0.636) in Group II and (P < .014, r = 0.812) in Group III-A (thus, low PZL affects both T-8 a nd B lym counts); and 2) between PZL-T-8-T-4/T-8-B lym in Group II (P < .014, r = 0.660) and Group III-A (P < .023, r = 0.850). However, the same relations were not seen when the plasma-zinc value was normal or after zinc supplementation. We did not come across any report in the literature concerning regression analyses and curve illustrations in c hildren with upper respiratory tract infection and low plasma zinc lev el. In conclusion, children with chronic upper respiratory tract infec tions presenting a low plasma zinc level would seem to benefit if zinc is supplemented. (C) 1997 Wiley-Liss, Inc.