Evaluation of the Ph. Eur. anti-A and anti-B assay on a pipetting robot in combination with a camera guided reading mode.

The main objective of this study was the standardization of the direct anti-A, anti-B haemagglutination assay for immunoglobulin products in microtitre plates and gelcards by automation on a liquid handling robot. In addition, the evaluation of the pipetted microtitre plates with a computer-controlled camera was investigated and these results were related to titres from visual live reading. The titres obtained with the automated and the manual assay in microtitre plates and gelcards were compared. They were in excellent agreement: the titres of samples processed with the automated method varied maximally one titre step relative to the median titres of the same sample analysed with the manual method. The implementation of a camera guided test plate reading further increased the repeatability of the reported titres. In summary, the automated haemagglutination assay combined with a camera improved the consistency plus the traceability of the results and reduced the required hands-on time.

Anti-A and anti-B haemagglutinin levels in intravenous immunoglobulins: are they on the rise? A comparison of four different analysis methods and six products.

Recent reports of severe haemolytic reactions upon high dose treatment with new generation intravenous immunoglobulins (IVIGs) prompted us to examine the anti-A and anti-B haemagglutinin content of these therapeutics. We compared four different test methods, namely the indirect and direct haemagglutination test as described in the European Pharmacopoiea (Ph. Eur.) and two commercial gelcard systems with the aim to define the most reliable method for a large-scale comparison of different IVIG products. Absolute titres varied when the same samples were analyzed by the four methods, while the relative ranking of six different IVIG preparations representing different manufacturing classes was identical. New generation IVIGs showed 1-2 titre steps higher anti-A titres than the older products. Haemagglutinin titres of all 48 IVIG batches analyzed were within the current Ph. Eur. specification of ≤1:64 when tested by the official pharmacopoeial method. Based on efficiency, reliability and lower costs, the direct gelcard method could be a valid alternative to the official Ph. Eur. method to serve as a limit test. However, due to the highest intermediate precision, the official Ph. Eur. method seems to be most suitable to compare haemagglutinin titres of different IVIG products.