TY - JOUR T1 - Complement activation predicts adverse pregnancy outcome in patients with systemic lupus erythematosus and/or antiphospholipid antibodies JF - Annals of the Rheumatic Diseases JO - Ann Rheum Dis SP - 549 LP - 555 DO - 10.1136/annrheumdis-2017-212224 VL - 77 IS - 4 AU - Mimi Y Kim AU - Marta M Guerra AU - Elianna Kaplowitz AU - Carl A Laskin AU - Michelle Petri AU - D Ware Branch AU - Michael D Lockshin AU - Lisa R Sammaritano AU - Joan T Merrill AU - T Flint Porter AU - Allen Sawitzke AU - Anne M Lynch AU - Jill P Buyon AU - Jane E Salmon Y1 - 2018/04/01 UR - http://ard.bmj.com/content/77/4/549.abstract N2 - Objective Studies in mouse models implicate complement activation as a causative factor in adverse pregnancy outcomes (APOs). We investigated whether activation of complement early in pregnancy predicts APOs in women with systemic lupus erythematosus (SLE) and/or antiphospholipid (aPL) antibodies.Methods The PROMISSE Study enrolled pregnant women with SLE and/or aPL antibodies (n=487) and pregnant healthy controls (n=204) at <12 weeks gestation and evaluated them monthly. APOs were: fetal/neonatal death, preterm delivery <36 weeks because of placental insufficiency or preeclampsia and/or growth restriction <5th percentile. Complement activation products were measured on serial blood samples obtained at each monthly visit.Results APO occurred in 20.5% of SLE and/or aPL pregnancies. As early as 12–15 weeks, levels of Bb and sC5b-9 were significantly higher in patients with APOs and remained elevated through 31 weeks compared with those with normal outcomes. Moreover, Bb and sC5b-9 were significantly higher in patients with SLE and/or aPL without APOs compared with healthy controls. In logistic regression analyses, Bb and sC5b-9 at 12–15 weeks remained significantly associated with APO (ORadj=1.41 per SD increase; 95% CI 1.06 to 1.89; P=0.019 and ORadj=1.37 per SD increase; 95% CI 1.05 to 1.80; P=0.022, respectively) after controlling for demographic and clinical risk factors for APOs in PROMISSE. When analyses were restricted to patients with aPL (n=161), associations between Bb at 12–15 weeks and APOs became stronger (ORadj=2.01 per SD increase; 95% CI 1.16 to 3.49; P=0.013).Conclusion In pregnant patients with SLE and/or aPL, increased Bb and sC5b-9 detectable early in pregnancy are strongly predictive of APOs and support activation of complement, particularly the alternative pathway, as a contributor to APOs. ER -