Detection of anti-IgA antibodies using the particle gel immunoassay: a rapid test for increased patient safety.

BACKGROUND: Patient safety is a major issue in transfusion medicine and commands continuous efforts to develop valid control methods aiming to avoid serious transfusion-related complications. Anti-IgA antibodies can cause anaphylactic transfusion reactions in IgA-deficient individuals. Since standard quantitative methods for anti-IgA measurement require considerable time to be performed, in an emergency situation it can be a challenge to prevent or to quickly interpret and manage acute transfusion reactions suspected to be a consequence of anti-IgA. The purpose of this study was to test and validate at our transfusion centre a rapid assay for the identification of patients with anti-IgA antibodies.

MATERIALS AND METHODS: Forty-six samples (6 from healthy controls and 40 from IgA-deficient patients) were collected. Sera were analysed blindly by three different clinical laboratory technologists using two DiaMed particle gel immunoassays (ID-PaGIA) for IgA deficiency and for antibodies to IgA. The results were subsequently checked with the results of a fluorescence enzyme immunoassay conducted in the reference immunology laboratory.

RESULTS: The ID-PaGIA had a sensitivity of 91.7% and specificity of 97.1% for the IgA deficiency test. With regards to the detection of anti-IgA antibodies, the sensitivity was 89.3% and the specificity 100%. The reproducibility of the test was 100%.

DISCUSSION: The ID-PaGIA screening assays are suitable for the investigation of transfusion-related anaphylactic reactions in a routine blood bank laboratory. Although the gel card technique does not quantify the level of anti-IgA antibodies, it is readily available, providing an effective and simple method for the diagnosis of anti-IgA related anaphylaxis and guidance for the appropriate transfusion practice in an emergency.