Maternal Serum Ischemia-Modified Albumin: A Biomarker to Distinguish Between Normal Pregnancy and Preeclampsia?

OBJECTIVE: To determine whether a biological marker of ischemia, ischemia-modified albumin (IMA), alone or normalized to albumin serum concentration, was modified during the course of pregnancy and so could be used for discrimination between normal pregnancy and preeclampsia. METHODS: Serum IMA concentrations and IMA to serum albumin ratio (IMA/alb) were compared in 22 nonpregnant healthy women (NP), 19 healthy pregnant women (HP) and 20 pre-eclamptic women (PE). Influence of age of gestation on these markers was also investigated. RESULTS: IMA to albumin ratio (IMA/alb) was significantly increased in HP compared with NP (IMA/alb. HP: 2.60 +/- 0.38 kU/g and IMA/alb. NP: 2.10 +/- 0.22 kU/g; p < 0.05). Both IMA and IMA/alb were significantly elevated during PE compared with HP (IMA HP: 98.4 +/- 9.2 kU/l and IMA PE 116.9 +/- 12.3 kU/l, p < 0.001; IMA/alb HP: 2.60 +/- 0.38 kU/g and IMA/alb PE: 3.79 +/- 0.75 kU/g p < 0.001)). Both IMA and IMA/alb were increased in PE up to delivery. No correlation could be demonstrated between gestational age and maternal IMA both in HP (r = 0.13; p = 0.071) or PE (r = 0.05; p = 0.318). CONCLUSIONS: IMA and IMA normalized to albumin appear to be significantly increased during pathological pregnancies. These results confirm that IMA could be used as a biological marker of preeclampsia. These data need to be confirmed by determining intra-individual IMA change during normal and pathological pregnancy.