Does Transfusion of Red Blood Cells Impact Germline Genetic Test Results?

Maggie A Diguardo,Ann M Moyer,Scott A Hammel,Eapen K Jacob,Jennifer L Oliveira,Craig D Tauscher,Sarah J Kester,Christopher D Hofich,Sarah E Kerr,Victor J Mahaffey,Katelyn K Heaser

doi:10.3390/jpm10040268

Abstract

Purpose: molecular testing is often indicated for recently transfused patients. However, there are no guidelines regarding the potential interference from donor DNA or whether it is necessary to wait for a period of time post-transfusion prior to genetic testing. While the majority of patients are transfused in the non-trauma setting using leukoreduced (LR) red blood cell products, the degree of leukoreduction varies among centers and is not universally practiced. Methods: whole blood units collected from anonymous donors were used in an in vitro transfusion model. One unit was split: half being leukoreduced simulating a leukopenic recipient and half left untreated. Donors were simulated by leukoreduced, partially leukoreduced (PLR), or non-leukoreduced units, transfused in 2, 5, or 16 unit equivalents. DNA from the combinations were subjected to short tandem repeat (STR) analysis for chimerism detection. Results: donor DNA was not detectable in any of the LR combinations, but detected in the PLR combinations, ranging from 0.1 to 1.5% donor DNA in the immunocompetent recipient and 6.3–27.8% in the leukopenic recipient. Non-LR donor DNA was also detected (13–95%). Conclusion: donor-derived DNA from leukoreduced blood products is unlikely to interfere with the interpretation of germline genetic testing in immunocompetent recipients but may interfere in immunocompromised recipients.

Highlights

IntroductionIs it ok to order a genetic test or do I need to wait?” is a commonly encountered question in the clinical genetics laboratory due to concerns about the possible presence of donor DNA in the transfused blood product(s)
Transfusion-associated microchimerism has been well documented in trauma patients receiving both whole and leukoreduced blood products; study results have been mixed regarding the presence of donor DNA from the transfusion of leukoreduced (LR) blood components in non-trauma patients [4,5,6,7,8,9,10]
Given that no donor DNA was detectable in the simulated transfusion of any amount of LR product in the leukopenic recipient, the short tandem repeat (STR) chimerism test for the simulation of 16 units of LR product to an immunocompetent recipient, which failed, was not repeated

Summary

Introduction

Is it ok to order a genetic test or do I need to wait?” is a commonly encountered question in the clinical genetics laboratory due to concerns about the possible presence of donor DNA in the transfused blood product(s). While most medical centers currently transfuse leukoreduced red blood cell products for non-trauma patients, it is not a requirement; approximately 70% of RBC and platelet products are pre-storage leukoreduced in the United States [11]. Due to the underlying indications for these tests, it is not uncommon for a number of these subspecialty patients to have received a red blood cell (RBC) transfusion and since the most common specimen collected for molecular testing is peripheral blood, the possibility of microchimerism conveys potential impacts for testing. We sought to determine what quantity, if any, of infused LR, partial-LR (PLR) or non-LR (NLR) RBC units lead to detectable donor DNA in both simulated immunocompetent and compromised patient (recipient) blood samples and how this may impact the spectrum of genetic testing

Methods

Results

Conclusion