Increased circulating heat shock protein 27 (HSPB1), heat shock protein 60 (HSPD1) and heat shock protein 90 (HSPC1) levels in normal pregnancy and preeclampsia.

OBJECTIVE

The aim of this study was to evaluate circulating levels of heat shock protein 27 (HSPB1, Hsp27), heat shock protein 60 (HSPD1, Hsp60) and heat shock protein 90 (HSPC1, Hsp90) in a large cohort of healthy non-pregnant and pregnant women, as well as in patients with preeclampsia. In addition, we investigated whether serum levels of these heat shock proteins are associated with clinical characteristics and routine laboratory parameters of the study population.

METHODS

The study included 60 women with preeclampsia, 60 healthy pregnant women with uncomplicated pregnancies and 59 healthy non-pregnant controls. Serum concentrations of Hsp27, Hsp60 and Hsp90 were measured with ELISA. Standard clinical chemistry parameters were assessed on an automated analyzer. Statistical analyses were performed using nonparametric methods.

RESULTS

Serum levels of Hsp27, Hsp60 and Hsp90 were significantly higher in healthy pregnant women compared with healthy non-pregnant controls. Moreover, preeclamptic patients exhibited significantly elevated levels of all three heat shock proteins compared with both control groups. In the preeclamptic group, serum Hsp27 levels showed significant positive correlations with serum bilirubin and lactate dehydrogenase activity. Hsp60 levels were positively correlated with blood urea nitrogen, creatinine, aspartate aminotransferase activity and lactate dehydrogenase activity. Hsp90 levels showed a significant positive correlation with aspartate aminotransferase activity.

CONCLUSIONS

Moderately increased circulating levels of Hsp27, Hsp60 and Hsp90 in otherwise healthy pregnancies may reflect adaptive physiological responses. In contrast, markedly elevated levels observed in preeclampsia may be associated with placental ischemia and oxidative stress, as well as maternal systemic inflammation, endothelial dysfunction, and tissue injury in both placental and maternal organs.