Are there any additional mechanisms for haemolysis in HELLP syndrome?

HELLP syndrome is a microangiopathy that leads to severe maternal complications. The objective of this study was to identify any additional mechanisms that could have contributed to HELLP syndrome-induced haemolysis. This is a pilot, prospective and observational study that lasted 9months. All patients with HELLP syndrome treated at academic tertiary care women hospital accepted to participate. Sixteen patients were included. In ten patients (63%), schizocytes were detected following a blood smear test. Six patients (38%) were diagnosed with a partial expression deficiency of proteins regulating the complement system (CD 55 or CD 59). In nine patients (56%), an activation of the complement classical pathway was detected. In two patients (13%), an ADAMTS 13 activity below 30% was detected. Three patients (19%) were diagnosed with a folate deficiency and one (6%) with an antiphospholipid syndrome. All patients developed maternal or fetal morbidity including nine (56%) an acute kidney injury. All patients but one had at least one additional mechanism that could contribute to haemolysis, besides a simple physical injury. Larger studies should be promoted to understand haemolysis in HELLP syndrome.