Plasma zinc level and thymic hormone activity in young cancer patients
E Mocchegiani, P Paolucci, D Granchi, L Cavallazzi, L Santarelli and N Fabris
Gerontology Research Department, Italian National Research Centers on Aging
(INRCA), Ancona.
It has been reported that in many neoplastic diseases, including leukemia,
alterations in plasma zinc levels may frequently occur, although the causes
for such alterations have yet to be clearly defined. Since zinc is required
to induce biological activity to thymulin (Zn-FTS), a biochemical defined
thymic hormone, and marginal zinc deficiencies may prevent its peripheral
biological activation, we investigated the plasma level of zinc and of both
active thymulin (Zn- FTS) and total zinc saturable thymulin (Zn-FTS + FTS)
in 91 young patients affected by acute lymphoblastic leukemia (ALL) at
various stages of the disease. It was discovered that the plasma zinc level
was reduced at the onset and relapse, whereas in complete remission and in
off-therapy it was in the normal range. Total zinc-saturable thymulin
concentration did not change during the disease, whereas the active
fraction was reduced at the onset and in relapse when compared with values
observed in the other stages of the disease or in healthy controls. These
data suggest that zinc plasma deficiency is present in ALL patients at the
onset and during relapse, and that such a deficiency causes a decrease in
the activity of thymulin despite a nearly normal production by the thymus.
An impairment of peripheral immune efficiency in ALL patients is commonly
found. The existence of positive correlations between zinc or active
thymulin and peripheral immunological parameters (phytohemagglutinin [PHA]
and concanavalin A [ConA]) at various stages of the disease suggests a link
between derangement of peripheral immune function, thymic hormone activity,
and zinc failure. These findings, considered together, suggest the
possibility of a carefully controlled clinic trial with zinc in ALL
patients at the onset and in relapse even in the light of in vitro
ineffectiveness of physiological zinc or thymulin concentrations on the
duplicative index of human lymphoblastoid cells.
Volume 83,
Issue 3,
pp. 749-757,
02/01/1994
Copyright © 1994 by The American Society of Hematology
