Anti–Rh D Activity of Commercial Intravenous Immunoglobulin Preparations

Abstract

BACKGROUND AND OBJECTIVES: The presence of antibodies against Rh D in intravenous immunoglobulin (IVIG) products has been proposed as causing adverse reactions and blood grouping problems, although data on the incidence and titre of such antibodies is sketchy. This study was conducted to investigate methodology for carrying out haemagglutination tests on IVIG products, and to examine in retrospect 200 IVIG batches for the presence of anti-D and other haemagglutinins. MATERIALS AND METHODS: Batches of commercial IVIG products were tested using the low-ionic-strength indirect antiglobulin test (LIAT). Positive batches were further investigated using a typed red cell panel and direct haemagglutination tests. RESULTS: 44 batches of IVIG gave positive LIAT. Of these, 12 contained specific anti-D. 11 batches had LIAT anti-D titres of 2-8; a further batch contained anti-D with a LIAT titre of 64. The remaining 32 batches agglutinated all erythrocyte phenotypes tested with LIAT titres </=4; 14 of these batches showed positive direct haemagglutination and the presence of rouleaux. CONCLUSION: 6% of commercial IVIG batches contained specific anti-D, including one batch (0.5%) showing unusually high titre. 16% of batches contained haemagglutinins of unknown/non-specificity.