Objectives to evaluate the impact of thrombotic microangiopathy (TMA) on perinatal and maternal outcomes in patients with systemic lupus erythematosus (SLE).
Methods This study included 21 SLE patients with pregnancy, who developed TMA signs during pregnancy. Patients underwent general survey, clinical and laboratory assessment for disease activity and APL-antibodies. All of them had low SLE-activity indices.
ResultsTMA signs were found in 7/21 SLE patients (33%). Patients with TMA had significantly higher systolic and diastolic blood pressure (P≤0.05), higher serum creatinine and lower estimated glomerular filtration rate (P≤0.05) than that of those without TMA lesions (tabl.1). APLA positivity was significantly more frequent in patients with TMA (3/7 vs 0/14). TMA onset in 2 patients occurred before 20 gestational weeks, 5/7 have developed PE signs (23–38 weeks), only 3/7 had classical HELLP syndrome. There was no PE in patients without TMA. There was a significant association between the detection of TMA and adverse perinatal outcomes (tabl.2).
Patient with TMA and SLE had a poor outcome and most severe course: 5/7 had a PE (3/7 developed HELLP),3/7 had antenatal fetal death, 3/7had signs of heart damage,5/7 a variety of neurological manifestations. Despite of PE signs in 5/7 with TMA the blood sFlt1/PLGF levels were slightly above normal (average sFlt/PLGF levels in preeclampsia without SLE in our another study is 404,47)
Conclusions TMA is not an uncommon disorder in pregnant patients with SLE. It is associated with APLA positivity only in 1/3 cases. TMA was significantly associated with renal impairment, systemic hypertension and adverse perinatal outcomes. Less increased ratio of sFlt-1/PlGF in TMA patients than “pure” PE may confirm that PE in patients with TMA is not a condition due to angiogenic factors imbalance. Circulating concentrations of angiogenic factors appear not to be suitable markers to assess the severity of PE and adverse outcomes in SLE patients. Thus, TMA may be an important cause of renal injury and renal dysfunction in a subset of pregnant patients with SLE and associated with worse renal and perinatal prognosis. Complement over-activation via both classical (SLE+APS) and alternative pathways might play an important role in the pathogenesis of TMA in SLE.
Disclosure of Interest None declared