BENEFICIAL EFFECT OF GLUCOCORTICOIDS ON THE COURSE OF HAEMATOGENOUSLYACQUIRED STAPHYLOCOCCUS-AUREUS NEPHRITIS

The effect of combined antibiotic and corticosteroid treatment on the course of haematogenously acquired Staphylococcus aureus nephritis was studied. Mice were given a single injection of S. aureus producing to xic shock syndrome toxin-1 in a dose capable of inducing a high freque ncy of inflammatory kidney lesions and divided into three groups accor ding to a treatment regimen. In all untreated animals inflammatory inf iltrates were seen in kidney cortex and medulla with high frequencies of glomerular (90%) and tubular damage (50%) as well as fibrotic chang es (50%). The treatment with antibiotics alone reduced significantly o nly the occurrence of focal inflammatory infiltrates. In contrast, the mice treated with a combination of antibiotics and corticosteroids di splayed in 64% of cases normal histological kidney appearance and a si gnificant decrease in occurrence of glomerular (P<0.01) and tubular (P <0.05) lesions. Immunohistochemically, the combined treatment resulted in a more pronounced decrease in numbers of CD4, IL-2R (four to fivef old) and CD8 positive cells in kidney inflammatory lesions compared to antibiotics only treated group. Thus, glucocorticoids in association with antibiotics are shown to improve the outcome of septic murine nep hritis, possibly due to suppression of kidney infiltrating T cells.