POSITIVE DIRECT ANTIGLOBULIN-TEST DUE TO ANTIPHOSPHOLIPID ANTIBODIES IN NORMAL HEALTHY BLOOD-DONORS

Objectives: Positive direct antiglobulin tests (DAT) occur occasionall y, without obvious cause, among normal blood donors. This is sometimes associated with a false-positive serologic test for syphilis. Positiv e DATs due to antiphospholipid antibodies (APAbs) are well documented in the antiphospholipid syndrome with systemic lupus erythematosus and the primary antiphospholipid syndrome. Methods: Using conventional ha ematologic and serologic methods, we tested 474,545 normal blood donor s in the west of Scotland during the years 1991 through 1993. Results: We identified 42 normal blood donors with a positive DAT and observed three who had positive DATs and false-positive VDRL tests, all of who m expressed raised APAbs. Conclusion: APAbs may be an incidental cause of positive DATs among healthy blood donors.