Implementation of a molecular genotyping protocol for patients with warm autoantibodies

Warm autoantibodies (WAAs) cause delays and additional expenses while determining suitable products when using a traditional protocol (TP). In 2013, Carter BloodCare Immunohematology Reference Laboratory (IRL) introduced a molecular protocol (MP) for patients with WAAs.

Retrospective review of records for samples referred to the IRL from November 2004 to September 2020, was performed. Referrals, alloantibody(ies), gender, and age were recorded. Additionally, the count of common clinically significant antigens needed for phenotypically matched red blood cells (RBCs) were recorded for patients in MP. To further analyze charges and time spent testing patients with WAAs, 300 patients were selected.

Analysis of average charges to the referring hospital and time spent testing in the IRL determined savings at two or more referrals. Overall, 219 of 300 (73%) of patients in the study met or exceeded the number of referrals. Further analysis shows that while the population of patients with WAA (n = 300) shared similar demographics, there was a statistically significant difference between the average time testing patients in TP (M = 264.18, SD = 15.06) and MP (M = 156.00, SD = 90.37), t(157) = 14.46, p < .001, 95% confidence interval [CI] (93.41-122.97). Additionally, the assumption that each patient received two RBCs per referral provided no statistically significant difference between average charges to the hospitals of patients in TP (M = 1222.58, SD = 165.69) and MP (M = 1269.78, SD = 433.52), t(192) = -1.25, p = .214, 95% CI (-121.95-27.54).

The MP has been effective in saving time spent testing patients with WAAs, which benefits referring hospitals, patients, and IRLs. Charges for prophylactic phenotypically matched blood were negligible and a MP would alleviate some of the current laboratory difficulties while providing safe products to patients.