Pilot investigation demonstrating positive autoantibody testing of Australian intravenous immunoglobulin products

Sam Salman, Nic Acquarola, Christine Bundell, Paul Sjollema, Andrew P. McLean-Tooke, Lloyd D’orsogna

Research output: Contribution to journalAbstract/Meeting Abstract

Abstract

Background: Intravenous immunoglobulin (IVIg) is used in antibody deficiency and treatment of autoimmune disorders. Produced from the pooled plasma of more than 1,000 donors, positive testing of autoantibodies has been reported for some products.1 Currently, there is no data for the three IVIg products available in Australia.

Methods: Residual amounts of three different lots of Intragam 10, Privigen and Flebogamma were diluted 1:10 in negative serum (final product concentration of 10 g/L to approximate human IgG concentration) before they were run on a battery of autoimmune antibody tests at PathWest Laboratories.

Results: Testing for anti-GAD, anti-TPO and anti-TG antibodies were low/moderate positive with borderline results for anti-IA-2 for all three products. A ‘flat’ cANCA was seen with Intragam without a PR3/MPO antibody as well as borderline IgG anti-cardiolipin while anti-parietal cell antibody was seen with the other two products.

Discussion: All three IVIg products available in Australia had positive autoantibody testing. Some differences were found which may arise from donor selection or production methods, as the positive result may represent true antibody or interfering factors.2 Clinicians should be aware of the possibility of false positive results for some autoantibody tests in patients receiving IVIg.
Original languageEnglish
Pages (from-to)S68
JournalPathology
Volume51
DOIs
Publication statusPublished - 1 Feb 2019

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