Pre-eclampsia

Purpose:
The Programme aims to assess the performance of organisations utilising biochemical markers to aid in the diagnosis of pre-eclampsia in pregnancy. The NICE guideline on hypertension in pregnancy defines pre-eclampsia as new hypertension with significant proteinuria after 20 weeks’ gestation. Biochemical Markers for pre-eclampsia include, Placental growth factor, (PlGF) used on its own, or as a ratio to Soluble fms-like tyrosine kinase-1 (sFlt-1 or sVEGFR-1) i.e sFlt-1 / PIGF ratio.

Clinical use of biomarkers – NICE Diagnostics guidance [DG23] May 2016 Recommendations:

1.1 The Triage PlGF test and the Elecsys immunoassay sFlt-1/PlGF ratio, used with standard clinical assessment and subsequent clinical follow-up, are recommended to help rule-out pre-eclampsia in women presenting with suspected pre-eclampsia between 20 weeks and 34 weeks plus 6 days of gestation.

When pre-eclampsia is not ruled-out using a PlGF-based test result, the result should not be used to diagnose (rule-in) pre-eclampsia.

1.2 The Triage PlGF test and the Elecsys immunoassay sFlt-1/PlGF ratio, used with standard clinical assessment and subsequent clinical follow-up, show promise in helping to diagnose (rule-in) pre-eclampsia in women presenting with suspected pre-eclampsia between 20 weeks and 34 weeks plus 6 days of gestation. However, there is currently insufficient evidence to recommend their routine adoption for diagnosing pre-eclampsia in the NHS. Further research is recommended on using these tests in women with suspected pre-eclampsia to rule-in pre-eclampsia.

Scope:
The programme aim is to cover the clinically relevant range, i.e. PlGF < 12 pg/ml to ≥100 pg/ml and sFlt-1/PlGF ratio of < 33 to > 110. However, the analytical measuring range will also be assessed where appropriate. The programme is suitable for both Laboratory and POCT applications.

Three liquid human samples are distributed monthly, with a minimum of 36 samples distributed over the year covering a wide clinically relevant range. The samples consist of endogenous samples from patients along with a panel of linearly related samples produced from donations from healthy volunteers spiked with PlGF and sFlt-1. They are distributed on a number of occasions over that period which allows for the assessment of the organisation’s and method’s performance, including linearity, bias, within and between batch imprecision.

Post – analytical interpretation of pre-eclampsia risk outcome is also assessed.