Introduction
Hypertensive pregnancy diseases affect up to 10 % of all pregnancies
worldwide.1,2 Among them are preeclampsia,
characterized by hypertension and proteinuria as well as HELLP syndrome,
a multisystemic disorder, defined by haemolysis, elevated liver enzymes
and low platelet count.3 The HELLP syndrome shares a
variety of features with other liver diseases, which compromise
approximately 3% of all pregnancies worldwide.4 Acute
fatty liver of pregnancy (AFLP) is a rare but often devastating disease
with an incidence that varies between 1:7000 and 1:20’000
pregnancies.5 AFLP and HELLP syndrome share multiple
clinical symptoms and up to date for both clinical conditions delivery
remains the only treatment. Some clinical approaches recommend immediate
delivery in AFLP whereas in HELLP syndrome delivery can be delayed, in
particularly before 34 gestational weeks to assure fetal lung maturation
following corticoid administration. 6-8 Compared to
HELLP syndrome AFLP, however, carries an even higher risk of adverse
maternal and fetal outcome.9 Patients affected by
HELLP syndrome with or without preeclampsia and those compromised by
AFLP share - apart from clinical features - also common laboratory
findings such as thrombocytopenia, haemolysis and especially elevated
liver enzymes.10 A prerequisite for prompt diagnosis
is a robust diagnostic tool to differentiate between these
liver-associated pregnancy complications with clinical and laboratory
overlapping features.
The gold standard for the diagnosis of AFLP is histological confirmation
following liver biopsy. These interventions, however, are rarely
performed due to the risk of haemorrhages and the urgent need to deliver
affected patients. Therefore, non-invasive Swansea criteria have been
proposed to identify patients with AFLP.5, 11 In a
large population-based prospective study, Knight et al have shown that
six or more Swansea criteria reasonably well agreed with the clinical
diagnosis.
Angiogenic factors play an important role in the pathogenesis of
placenta-associated complications such as preeclampsia with and without
HELLP syndrome.12 Angiogenic profiling using
sFlt-1/PLGF ratio can be helpful to identify women with impending
preeclampsia and these markers have also the potential to tailor the
management in women with established preesclampsia although this point
is still controversial.13-15 The data on angiogenic
factors in AFLP is scarce. Initial studies investigating the angiogenic
status in AFLP patients assume that the anti-angiogenic condition
aggravates compared to patients with HELLP syndrome.16,
17
The aim of this study was to analyse the angiogenic profile in
pregnancies compromised by AFLP and to assess whether angiogenic factors
may be useful to discriminate between AFLP and HELLP syndrome.