Effect of Sera from Preeclamptic and Chronic Hypertensive Women on the Interleukin-6 Secretion in Human Umbilical Vein Endothelial Cell Culture

Kim, A; Koo, J N; Kim, J T; Lee, P Y; Lee, I S; Oh, W I; Mok, J E

Abstract

OBJECTIVES
Our purpose was to determine whether the sera of preeclamptic and chronic hypertensive women activate the interleukin-6 (IL-6) secretion in human umbilical vein endothelial cell (HUVEC) culture. Materials and
METHODS
Maternal sera were collected from 10 normal pregnant women, 10 preeclamptic patients, and 7 chronic hypertensive patients. Endothelial cells were isolated from human umbilical vein and cultured until cells were confluent. After the cells were incubated with the above sera for defined periods (0 hour, 6 hours, 12 hours, 24 hours, 48 hours), supernatants were collected for IL-6 assay. Concentration of IL-6 was measured by sensitive ELISA method. Statistical analysis was done by Kruskal-Wallis ANOVA, Dunn test, Chi-square analysis of contingency tables, and Mann-Whitney U test.
RESULTS
IL-6 was not detectable (less than 1 pg/ml) until 12 hour-incubation in all three groups. IL-6 was detected in small proportion of each of three groups only after 24 hour-incubation, but there was no statistical significance in the concentration of IL-6 among the groups (normal; median 0 pg/ml with range 0 to 4.3 pg/ml, preeclamptic; median 0 pg/ml with range 0 to 10.2 pg/ml, chronic hypertensive; median 0 pg with range 0 to 13 pg/ml). After 48 hour-incubation, preeclamptic group showed significantly higher concentrations of IL-6 than those of normal group (median 29.2 pg/ml with range 19.8 to 46.8 pg/ml vs. median 17.7 pg/ml with range 9.28 to 28.9 pg/ml, p<0.05). However, there was no statistical difference in the concentrations of IL-6 between chronic hypertensive and normal group (median 19.4 pg/ml with range 0 to 43.6 pg/ml vs. median 17.7 pg/ml with range 9.28 to 28.9 pg/ml).
CONCLUSION
It is suggested that sera of preeclamptic patients, not those of chronic hypertensive women,can activate the IL-6 secretion in HUVEC culture. This implys that preeclamptic sera may have a certain factor (s) which stimulate (s) cytokine secretion in HUVEC culture.