Adopting Automated Gel Testing in a Small Community Hospital Blood Bank: More Positive Antibody Screens and Failure to Accurately Type a Rare cisAB Genotype
RD Boyum, MA Brooks, JS Luster, BI Ruiz. Naval Hospital Pensacola, Pensacola, FL
Background: Automation is the primary advantage of using gel testing techniques rather than traditional tube testing in transfusion service laboratories. However, the performance characteristics of automated gel testing are not the same as those for traditional tube testing, and adopting this new technology poses unique challenges for small community hospital blood banks. We report an analysis of the first 13 months of automated gel technology use, to replace traditional tube testing, in a small community (US Navy) hospital.
Design: For data collected between April 1, 2006 and April 30, 2007, ABO/Rh typing, antibody screens, and antibody identification were performed using traditional tube testing with low ionic strength solution (LISS). For data collected between May 1, 2007 and June 30, 2008, ABO/Rh typing and antibody screens were performed using the Provue (Ortho-Clinical Diagnostics) automated gel testing system; antibody identifications were performed by a reference laboratory (Northwest Florida Blood Services, Pensacola, FL) using tube testing with low ionic strength solution (LISS) and polyethylene glycol (PEG).
Results: Of 2284 antibody screens performed with gel testing, 83 (3.63%) were positive, 42 (1.84%) were positive due to passively acquired anti-D (RhIg injection), and 20 (24.10% of all positive screens) had no antibody detected on confirmatory testing. Of 1606 antibody screens performed with tube testing, 31 (1.93%) were positive, 15 (0.93%) were positive due to passively acquired anti-D (RhIg injection), and 2 (6.45% of all positive screens) had no antibody detected on confirmatory testing. Antibody screening with automated gel testing detected a single case of anti-E, a clinically significant alloantibody, three months before it was detected and identified by tube testing. Automated gel testing failed to detect B antigen expressed by a rare cisAB genotype. When the same sample was testing using manual gel or traditional tube techniques, the B antigen was detected.
Conclusions: In comparison to traditional tube testing, automated gel testing apparently has increased sensitivity for the detection of both clinically insignificant (anti-D due to RhIg injection) and clinically significant (anti-E due to alloimmunization) antibodies. In contrast, automated gel testing has apparently decreased sensitivity for the detection of B-antigen expressed in a patient with a rare cisAB genotype; this decreased sensitivity was not seen with manual gel testing.
Wednesday, March 11, 2009 1:00 PM
Poster Session VI # 240, Wednesday Afternoon