An evaluation of the DiaMed assays for immunoglobulin A antibodies (anti‐IgA) and IgA deficiency

BACKGROUND: Immunoglobulin A antibodies (anti‐IgA) are rare but can cause transfusion‐associated anaphylaxis. The detection of anti‐IgA has traditionally been performed using a labor‐intensive hemagglutination assay in a limited number of reference laboratories.STUDY DESIGN AND METHODS: Two simple gel card assays are now available that can be used to screen for anti‐IgA and IgA deficiency. A total of 24 serum samples that had been previously assayed for anti‐IgA over a 3‐year period were used to assess the DiaMed anti‐IgA and IgA deficiency assays.RESULTS: The DiaMed assays correctly identified patients (n = 6) who had significant IgA deficiency and anti‐IgA. All patients with an abnormal anti‐IgA titer by hemagglutination assay and who were also IgA‐deficient had anti‐IgA detected using the DiaMed screening test. One patient, previously shown to have an IgA level of less than 0.067 g per L, failed to be detected as IgA‐deficient in the DiaMed IgA deficiency test; however, anti‐IgA were not present. Samples with slightly increased anti‐IgA titers tended to have normal IgA levels.CONCLUSION: The DiaMed gel card screening assays are appropriate screening tools for the investigation of transfusion‐related anaphylactic reactions and can be used in any routine blood bank laboratory.