To compare immune cell subsets and interferon (IFN) expression in placentas from patients with systemic lupus erythematosus (SLE), primary Sjögren’s disease (pSjD), antiphospholipid syndrome (APS), healthy controls (HC) and of women with adverse pregnancy outcomes (APO) without these systemic rheumatic diseases (SRD). This evidence concerns the gene IFNA1 and systemic lupus erythematosus.