[Detection and side effects of isoantibodies in intravenously administered immunoglobulin preparations].

Background: Intravenous immunoglobulins (IvIg) contain not only the declared antibodies against pathogenic microorganisms, but also all the other antibodies of the blood donors, e.g. against erythrocytic antigens.

Materials and methods: We tested 14 IvIg from 7 manufacturers (a total of 40 charges) for isoantibodies and irregular antibodies. To improve the reading of our tests we used the gel centrifugation method (ID-Microtyping-System, Fa. Diamed, Bensheim, Germany).

Results: The highest isoantibody titers were (in 8 charges) 1:32 or 1:64 in the Liss-Coombs test. Irregular antibodies were found in 5 IvIg (maximal titer 1:8).

Conclusions: Isoantibodies in the IvIg can influence blood group serologic tests. With an example of a newborn who had received IvIg we point to the potential danger of misinterpretation of a positive direct antiglobulin test after administration of IvIg. Therefore we recommend to carry out the direct antiglobulin test before administration of IvIg and to examine all eluates after a positive direct Coombs test not only with 0 RBCs but also with A or B RBCs of the AB0 blood group of the patient.