Cold-Reactive Autoantibodies - Reporting:
Many cold agglutinins are considered “nuisance” reactions during pre-transfusion compatibility testing, and efforts are made to avoid their inadvertent detection (e.g., by eliminating the use of room temperature/immediate spin phase testing during antibody screening and crossmatching and using anti-IgG without anti-C3 when performing the IAT).
Once a cold agglutinin has been confirmed, however, its presence should be reported so that the clinician may determine whether formal testing of titer or thermal amplitude is warranted. The results of these investigations may aid in the assessment of the cold agglutinin’s clinical significance, although, as with warm-reactive autoantibodies, the clinical significance of a cold-reactive autoantibody is best determined by assessing the patient for signs of disease (either hemolytic anemia or acrocyanosis).
Units crossmatched for patients with cold agglutinin disease are usually compatible, as cold agglutinins are generally non-reactive during IAT testing. Use of blood warmers during administration is almost never required except in the most extreme cases.