Problem: Low serum placental isoferritin (PLF), an immunosuppressive cytokine-like protein, was found in women with underlying placento-vascular dysfunction, such as intrauterine growth retardation and preeclamptic toxemia. The possible contribution of this placental product in the assessment of pregnant patients with either systemic lupus erythematosus (SLE) and/or antiphospholipid syndrome (APS) was investigated.
Method of study: Seventy-five healthy pregnant women used as controls and 25 preselected pregnant patients with either SLE and/or APS were enrolled in the study. Study patients were in remission during conception and all patients agreed to give 5 ml of venous blood at midgestation. The samples were frozen and analyzed retrospectively. After delivery, pregnancy outcomes were gathered from hospital records.
Results: Seventeen (68%) women had uneventful pregnancies and deliveries (normal) whereas 8 (32%) showed pathologic obstetric outcomes. Mean midgestational serum PLF levels were similar in the control and normal outcome groups (87 U/ml), whereas significantly lower levels (37 U/ml) were measured in the pathologic outcome group. Using a cutoff level of 10 U/ml, 85% from the normal outcome group and 15% from the pathologic outcome group were above this threshold level, with 60% specificity and 100% sensitivity.
Conclusions: These preliminary data suggest that PLF values may reflect placento-vascular functions. These may represent a predictive biomarker for developing obstetric complications in pregnant women with either SLE and/or APS.