The effect of lactic acid on mononuclear cell secretion of proinflammatory cytokines in response to group B streptococci.

Abstract

This study found that lactate alone had a stimulatory effect (207.1 +/- 16.3%; P = .001) on tumor necrosis factor (TNF)-alpha production by human mononuclear cells with the most profound secretion being at pathologic concentrations of 4-8 mM lactate. Furthermore, exposure of these mononuclear cells to group B streptococci (GBS, 10(5) cfu) resulted in TNF-alpha production of up to 621.1 +/- 42% of control; the combination of lactic acid and GBS increased TNF-alpha production up to 1019.3 +/- 16.1% (P = .001). The combination of GBS and lactate also enhanced the secretion of interleukin (IL)-1beta and IL-6. Lactate in pathologic concentrations, therefore, likely enhances the secretion of these inflammatory mediators and contributes to septic shock and meningitis caused by GBS.