Antibodies against glutamic acid decarboxylase in intravenous immunoglobulin preparations can affect the diagnosis of type 1 diabetes mellitus.

Background And Objectives: Intravenous immunoglobulins (IVIgs) contain various autoantibodies, including those against glutamic acid decarboxylase (GADAb), a valuable biomarker of type 1 diabetes mellitus. Passive transfer of GADAb from IVIgs to patients poses a risk of misdiagnosis, and information on the specific titres of GADAb and their impact on diagnostic accuracy remains limited. This study aimed to provide further insights into the origin of GADAb detected in patient serum following IVIg infusion.

Autoantibody profiles in intravenous immunoglobulin preparations: A possible cause of mistaken autoimmunity diagnosis.

Background: Intravenous immunoglobulins (IVIgs) derived from the pooled plasma of thousands of donors contain numerous types of IgG molecules, including autoantibodies commonly used to diagnose autoimmunity. While these autoantibodies can cause misinterpretation of serological tests for IVIg recipients, their profiles in IVIg preparations are not fully understood.

Study Design And Methods: Using binding-capability based immune assays, we measured 18 varieties of clinically relevant autoantibodies in domestic blood donor-derived IVIg products.