Intensive care patients with preeclampsia – Clinical risk factors and biomarkers for oxidative stress and angiogenic imbalance as discriminators for severe disease

Background: Approximately 180 mothers are treated in Swedish Intensive Care Units (ICU) due to preeclampsia each year. Although several clinical risk factors are known, prediction of critical disease is challenging. Two scavenger proteins, hemopexin (Hpx) and alpha-1-microglobulin (A1M) have been suggested to be associated with the oxidative stress seen in preeclampsia. The ratio of two other biomarkers, soluble fms-like tyrosine kinase (sFlt-1) to placental growth factor (PIGF), is predictive of adverse pregnancy outcomes. Methods: In total 121 women were included in this study where we compared risk factors for preeclampsia, plasma levels of Hpx and A1M in ICU-patients with preeclampsia (n = 41) compared to uncomplicated preeclampsia cases (n = 40) and normotensive pregnancies (n = 40), with the objective to identify clinical risk patterns for severe disease. The sFlt-1/PIGF ratio was investigated in early and late onset preeclampsia ICU-patients. Blood samples were collected at admission to ICU and within 27 h postpartum for all groups. Results: Hemopexin and A1M levels were significantly lower in the preeclampsia ICU-cohort compared to uncomplicated preeclampsia patients. The sFlt-1/PIGF-ratio was elevated in the ICU-patients but there was no difference between early and late onset preeclampsia. The ICU-patients had more clinical risk factors, refractory hypertension, and an increased rate of emergency Caesarean section. Conclusion: Intensive care patients have more clinical risk factors and a Hpx and A1M profile suggestive of depletion and thereby a reduced capacity to respond to oxidative stress. The ratios of sFlt-1/PIGF were high in the ICU-cohort and in accordance with pre-delivery levels predictive of adverse pregnancy outcomes.