NICE has recommended the Triage PlGF test (Alere International) and the Elecsys immunoassay sFlt-1/PlGF ratio (Roche Diagnostics), used together with clinical judgement, to help rule-out pre-eclampsia in women between their 20th and 35th week of pregnancy.
The Triage PlGF test and the Elecsys immunoassay sFlt-1/PlGF ratio measure levels of placental growth factor (PlGF) in the blood. PlGF is a protein involved in the development of new blood vessels in the placenta. In pre-eclampsia levels of PlGF can be abnormally low. In normal pregnancy, PlGF levels rise and peak at 26 to 30 weeks, so when PlGF levels do not rise during pregnancy this may be an indicator that the placenta is not developing properly.
The Elecsys immunoassay sFlt-1/PlGF ratio also measures soluble FMS-like tyrosine kinase-1 (sFlt-1), a protein which is thought to disable proteins associated with blood vessel formation, such as PlGF. In women who develop pre-eclampsia, the levels of sFlt-1 are thought to be higher than those seen in normal pregnancy.
The draft diagnostics guidance on tests to aid the assessment of suspected pre-eclampsia is available on the NICE website: http://www.nice.org.uk/guidance/indevelopment/gid-dt26
