To investigate whether -159C/T promoter polymorphism of the CD14 gene influences the CD14 expression as well as release in whole blood culture.One hundred and eighteen healthy human blood donors were included in the present study. CD14 mRNA expression and soluble CD14 levels were measured using a whole blood cell culture model with or without lipopolysaccharide (LPS) stimulation. The CD14 gene polymorphism was determined by polymerase chain reaction and subsequent HaeIII restriction enzyme digestion of the polymerase chain reaction products. TNF-alpha production in the whole blood culture was also measured.Among the 118 individuals, there were 40 subjects homozygous for the T allele (TT), 62 were heterozygous (CT), and 16 had the genotype CC. The CD14 mRNA expression in leukocytes and soluble CD14 levels in supernatant were higher in TT homozygotes and carriers of the genotype TC compared with individuals homozygous for the C allele (P < 0.05 or 0.01). In addition, the highest values of TNF-alpha production were found in TT homozygote [(352 +/- 215) pg/ml] compared with both genotype TC and CC [(261 +/- 163) pg/ml, (198 +/- 122) pg/ml, both P < 0.05].The -159C/T promoter polymorphism of the LPS receptor CD14 may influence the CD14 expression as well as release in whole blood culture, and it might be associated with TNF-alpha response to LPS stimulation.