THE DIRECT EMBRYOTOXICITY OF IMMUNOGLOBULIN-G FRACTIONS FROM PATIENTS WITH SYSTEMIC LUPUS-ERYTHEMATOSUS

PROBLEM: To determine if IgG fractions from sera of individuals with systemic lupus erthymatosus (SLE) were toxic to cultures of whole rat embryos. METHODS: Head-fold stage rat embryos (9.5 days of gestation) were cultured on media consisting of 50% rat serum containing IgG fractions isolated from plasmapheresis plasma of six subjects with SLE and six with other autoimmune diseases. Each fraction was tested at 11 mg/ml and those toxic were also tested at 7.5 and 4 mg/ml. RESULTS: Of the six SLE IgG fractions, four were embryotoxic (embryolethal or teratogenic) while only one of the six non-SLE fractions were embryotoxic. CONCLUSION: IgG fractions from subjects with SLE can be toxic to cultures of whole rat embryos in the absence of maternal tissues or influence. Such cultures of whole embryos may be useful to identify those antibodies that represent a risk for fetal loss as well as to understand their mechanisms of embryotoxicity.