Background/Case Studies: Warm autoantibodies (WAA) in patient samples cause delay and additional expenses when determining product suitability through traditional testing. In 2013, our Immunohematology Reference Laboratory (IRL) introduced a modified testing protocol for WAA patients that provides prophylactic phenotypically matched red blood cells (RBC) for qualifying patients with a molecular genotype. Patients subsequently referred to the IRL with WAA history, after initial visit, are investigated using either the traditional protocol (TP) or molecular protocol (MP). MP was only performed when antibody screen and DAT were reactive.
Study
Design/Methods: Retrospective record review was performed for IRL samples referred from 2004-2020. Referrals, alloantibodies, gender, and age were recorded. Additionally, the number of common clinically significant antigens needed to supply phenotypically matched RBCs for each patient was also recorded for the MP group. To analyze charges and time testing, 300 patients were randomly selected, and testing performed in each protocol was estimated. Initial investigations included Direct Antiglobulin Tests (DAT) (Polyspecific, IgG, and Complement), six antibody identification panels, one elution study, one red cell treatment, and one differential adsorption. TP included DATs, four antibody identification panels, one elution study, and one differential adsorption. MP included DATs and one antibody identification panel using both LISS and PEG enhancements.
Results/Findings: Analysis of charges and time spent on IRL testing determined there were savings at two or more referrals. Overall, 219/300 (73%) of patients met or exceeded the number of referrals for savings. Table 1 shows further analysis between the two groups. Demographics were similar while statistically significant (p < 0.001) differences were seen in both time and antigen typing required. Conclusions: The MP is effective in saving time and charges on WAA investigations for referring hospitals and the IRL after two visits. In this group, additional charges for molecular genotyping and providing phenotypically matched RBCs were not statistically significant and provides additional benefits to patients. Implementing a MP should be considered if equipped with acceptable inventory.
Importance of research: While workloads have increased due to an aging population and a steady increase in vacancy rates for immunohematology laboratory technical staff, automated molecular testing has been utilized to alleviate the burden of the repeat testing in patients with warm autoantibodies. This research explores the implementation of a molecular genotyping protocol for patients with warm autoantibodies and determines if the molecular protocol has been beneficial for both patients and testing laboratories.
