An unusual case of anti-D detection in two consecutive D+ patient samples: Antibody carryover on an automated gel platform.

BACKGROUND Laboratory results can be affected by sample to sample carryover. Carryover of different analytes occurring in automated clinical chemistry, immunology, hematology, and molecular laboratories is well described. However, carryover in a transfusion service laboratory is not reported in medical literature. MATERIALS AND METHODS Immunohematology testing results, demographic data, and clinical data were reviewed on three patients retrospectively from 2015 to 2019. RESULTS Type and screen samples tested on automated gel platform from two D+ patients were affected by anti-D carryover from a patient sample with a very high-titer anti-D. Additional immunohematology and molecular testing confirmed that anti-D in samples of two D+ patients was due to carryover. CONCLUSION A case of anti-D carryover caused false detection of anti-D in two D+ patients. Carryover can have implications for patient management. Transfusion laboratory staff need to be aware of it and investigate any unexpected results further.