Effects of Corticosteroids on Human Monocyte Function

Abstract

A B S T R A C T This report examined the effect of corticosteroids in vitro on human peripheral blood monocytes, essential cells in both immune and nonimmune cellular defense mechanisms. Monocyte chemotaxis in response to sera, Escherichia coli filtrate, and lymphokine chemotactic factor was markedly reduced (P < 0.01) by hydrocortisone succinate (HCS) at 16 Ag/ml. Methylprednisolone succinate and unesterified hydrocortisone produced similar impairment of monocyte chemotaxis while two drugs which unmodified do not enter cells, hydrocortisone phosphate (HCP) and cortisone acetate, had no effect on chemotaxis. HCS also significantly impaired monocyte random migration at 16 jug/ml. Monocyte bactericidal activity was reduced by HCS at 16 Ag/ml (P < 0.01) ) but was not affected by HCP even at 120 Lg/ml. In comparison, HCS did not alter granulocyte chemotaxis even at 500 Ag/ml, and bactericidal activity was reduced at 16 jg/ml (P < 0.01). Monocyte phagocytosis of cryptococci was reduced only 20% (P < 0.05) at 120 Ag/ml. HCS at 120 Ag/ml did not alter monocyte base-line or postphagocytic hexosemonophosphate shunt activity, viability by trypan blue exclusion, adherence to tissue culture flasks, or surface binding of IgG globulin. These corticosteroid-induced defects in monocyte function may contribute to reduced cellular defense during corticosteroid therapy.

Successful Additional Corticosteroid Treatment in a Patient with <i>Mycoplasm</i>a <i>pneumoniae</i> Pneumonia in whom a Monobacterial Infection was Confirmed by a Molecular Method Using Bronchoalveolar Lavage Fluid

“…The downregulation of the cell-mediated immune response by corticosteroids has been previously reported (14,15) and therefore the additional corticosteroid treatment during severe M. pneumoniae pneumonia may have a favorable effect by reducing the hyperimmunemediated pulmonary injury. In addition, corticosteroids downregulate the immune responses mediated by Th1 cells, and therefore corticosteroids may reduce the immunemediated pulmonary injury induced by M. pneumoniae.…”

Effect of corticosteroids on the human monocyte IgG and complement receptors.

“…In the latter study Atkinson et al demonstrated that IgG-sensitized erythrocytes were cleared in corticosteroid-treated guinea pigs as if they had fewer IgG molecules per red cell, suggesting a decreased recognition of immunoglobulin-or complement-coated cells by the macrophages of the reticuloendothelial system of the steroid-treated animal. Indeed recent studies have shown that corticosteroids can affect macrophage (9) and monocyte (10) activity. However, none of these studies have shown an effect of corticosteroids on monocyte or macrophage receptor function.…”

Possible Pivotal Role of Latent Chronic T. gondii Infection in the Pathogenesis of Atherosclerosis

“…GCs have been reported to interfere with a variety of both intra-and extracellular activities of mononuclear phagocytes, and GC receptors have been identified in monocytes and macrophages [725] . Hydrocortisone and prednisone diminished human monocyte chemotaxis [726] , bactericidal capacity [727,728] , receptor activity for IgG and C3 complement [727] , and specifically inhibited macrophage elastase, collagenase, and PAI secretion [729] . Moreover, GCs inhibited the expression and action of most cytokines [730] .…”