The bactericidal defect of neutrophil function with lithium therapy

Lithium in the treatment of neutropenia

PURPOSE OF REVIEW

The capacity of lithium to induce neutrophilia and increase circulating CD34(+) cells of marrow origin has long been known. Lithium has been the object of hematological investigations for many years, but no definitive use in hematology has yet emerged.

RECENT FINDINGS

We review the evidence that lithium increases granulocyte colony-stimulating factor (G-CSF) and augments G-CSF effects, showing its potential use in stem cell mobilization and engraftment of stem cell transplantation.

SUMMARY

We suggest possible therapeutic uses of lithium in neutropenia. In bone marrow transplantation, preharvest lithium-assisted hematopoietic stem cell mobilization may be useful as well.

The immunoregulatory effects of antidepressants

There is some evidence that major depression is accompanied by activation of the inflammatory-response system (IRS). It has been hypothesized that increased production of proinflammatory cytokines may play a role in the etiology of major depression. If increased production of proinflammatory cytokines is at all involved in the etiology of depression, one would expect antidepressive treatments to have negative immunoregulatory effects. This paper reviews the effects of antidepressants, such as tricyclic antidepressants (TCAs), selective serotonin reuptake inhibitors (SSRIs), heterocyclic antidepressants (HCAs), serotonin-noradrenaline reuptake inhibitors (SNRIs), lithium, l-5-hydroxytroptophan (L-5-HTP), reversible inhibitors of MAO-A (RIMA) on the production of proinflammatory cytokines, e.g. interferon-gamma (IFNgamma), and negative immunoregulatory cytokines and agents, e.g. interleukin-10 (IL-10). In depressed patients, prolonged treatment with antidepressants and mood stabilizers normalizes signs of activation of the IRS, such as increased serum IL-6 and acute phase protein concentrations. In vitro, it has been shown that various types of antidepressive drugs, including TCAs (imipramine; clomipramine); SSRIs (citalopram, fluoxetine, sertraline); lithium; SNRIs (venlafaxine); HCAs (trazodone); RIMAs (moclobemide) and L-5-HTP significantly suppress the ratio of IFNgamma/IL-10 production by peripheral blood immunocytes. These antidepressant drugs appear to have a common effect on the IRS, i.e. in vitro they increase the production of IL-10 by peripheral blood leukocytes. Thus, the results suggest that antidepressants have negative immunoregulatory effects. It may be speculated that antidepressants exert some of their antidepressant effects through their negative immunoregulatory capacities. Copyright 2001 John Wiley & Sons, Ltd.

Effects of short-term lithium treatment on peripheral blood lymphocytes and granulocytes in healthy volunteers

The effects of a short-term treatment with lithium carbonate on lymphocytes and granulocytes were studied in six normal subjects. The lithium effects are related to a direct, immediate and quickly reversible action of the drug on the bone marrow, as demonstrated by the granulocyte number and variations in Arneth's index. Although lymphocyte and granulocyte functions do not seem to be affected by lithium when investigated by the usual methods, the ability of the drug to counteract the theophylline-induced inhibition of cellular functions would suggest that lithium acts mainly through the modulation of intracellular levels of cyclic nucleotides. This is confirmed by evaluation of cellular cyclic 3',5'-adenosine monophosphate (cAMP). The above hypothesis could explain the quick onset and loss of lithium action on granulopoiesis.