ANTI-SC1 IN PREGNANCY

Anti‐Sc1 was detected in a gravida‐2 patient at 12 weeks' gestation. At 29 weeks, the antibody was found to be of the IgG3 subclass with a titer of 16, score 36, by the indirect antiglobulin test, and it produced 7 percent lysis by antibody‐dependent cellular cytotoxicity (ADCC) assay, a finding that suggested an unaffected fetus. The titer remained constant throughout the pregnancy, as did the IgG subclass and activity in the ADCC assay. At delivery of the full‐term infant, the cord hemoglobin was 13.5 g per dL and the direct antiglobulin test was positive (3 +) with anti‐IgG. The infant did not require transfusion. A sample taken 9 weeks after delivery showed 44 percent lysis in the ADCC assay. The anti‐Sc1 titer was 32, score 65. 1990 AABB