Peripheral blood mononuclear cells from patients with chronic renal failure release factors which suppress erythropoietin secretion <italic>in vitro</italic>

Abstract

Decreased production of erythropoietin (Epo) as a result of reduced renal mass is considered the main factor underlying the anaemia that is invariably associated with chronic renal failure (CRF). Other mechanisms such as accumulation of inhibitors of Epo also contribute. In this study we show that supernatant from peripheral blood mononuclear cells (PBMC) cultured from patients with CRF inhibits Epo release by Hep G2 cells in vitro. Ten patients (5 male) with CRF (mean age 42 years, range 25-60) were studied. Five were approaching end-stage renal failure and five were maintained on haemodialysis (HD). Ten apparently healthy volunteers were used as controls. Full blood counts and serum Epo (RIA) levels were determined and adherent PBMC were cultured for 48 h with and without LPS. There was a significant rise in TNF-alpha and IL1-beta levels measured in monocyte supernatant (MS) from patients and controls after LPS stimulation (P < 0.05) and in IL-1 alpha levels in patients (P < 0.05). IL-1 beta levels were higher in patients compared to controls both before and after stimulation with LPS (P < 0.05). Hep G2 cells were cultured in 5% CO2 and 20% O2 and incubated with MS from patients and controls for 24 h. Hep G2 harvest fluids were then analysed for Epo levels, which were expressed as a function of total cell protein (mU/mg). Epo production was inhibited by MS from patients compared to controls both before and after stimulation with LPS (P < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)