Multi-centre evaluation of pre-transfusional routine tests using 8-column format gel cards (DG Gel®)

Production of Feline Universal Erythrocytes with Methoxy Polyethylene Glycol

Blood group mismatch in veterinary medicine is a significant problem in blood transfusion, sometimes leading to severe transfusion reactions and even patient death. Blood groups vary from species to species and there are three known blood groups in cats: A, B and AB. While A-type cats are most common, there is a shortage of feline B-type blood groups in cats. By using methoxy polyethylene glycol (mPEG) to protect antigenic epitopes on red blood cells (RBCs), we aimed to find the optimal conditions for the production of feline universal RBCs. The surfaces of feline A-type RBCs were treated with mPEG at various molecular weights and concentrations. Agglutination tests showed that the coating of feline A-type RBCs with mPEG of 20 kDa and 2 mM blocked hemagglutination to feline anti-A alloantibodies over 8 h. While no differences in RBC size and shape between intact and mPEG-treated RBCs were seen, coating RBCs with mPEG inhibited the binding of feline anti-A alloantibodies. Furthermore, the mPEG-treated RBCs did not cause spontaneous hemolysis or osmotic fragility, compared to control RBCs. According to a monocyte monolayer assay, mPEG treatment significantly reduced feline anti-A antibody-mediated phagocystosis of RBCs. These results confirm the potential of using activated mPEG on feline A-type RBC to create universal erythrocytes for transfusion to B-type cats.

Investigation of Discrepant ABO Blood Grouping Results from an Autoanalyzer

Background

A paucity of studies evaluating failed cases of ABO grouping using autoanalyzers exists. We investigated autoanalyzer rejected cases, including serologically suspicious ABO subgroups and discrepant ABO blood grouping results from Erytra Eflexis (Grifols, Spain), to demonstrate efficient use of autoanalyzers for ABO grouping.

Methods

Samples requested for ABO grouping throughout 2020 were tested using two Eflexis instruments and standard ABO RhD and reverse grouping cards. Neonatal cards were not used. When necessary, a conventional tube technique (TUBE) was used to resolve rejected/discrepant Eflexis ABO grouping results.

Results

The overall sample rejection rate (RR) was 3.2% (628/19,466), 1.3% of which were due to various error flags and 1.9% for discrepant results. Cases from neonates ≤1 year old accounted for 35.3% of the rejected cases based on Eflexis results. The ABO groups with the highest and lowest RR (excluding neonates) were A and O, respectively. The 628 samples resulted in 682 rejections, which were frequently associated with reverse grouping, including 28.4% against A₁ and 54.5% for B red cells. Among 14 serologically weakened A and/or B blood groups, six A₂BW and two ABw, which had been missed by Eflexis, were detected using TUBE and our follow-up laboratory criteria.

Conclusions

The ABO group and a proportion of neonatal samples influenced the RR due to weak reverse grouping reactivity, especially toward B red cells. Confirmatory ABO grouping by TUBE in a new patient and/or extra rejection criteria for forward grouping are needed to detect cis-AB, which is relatively common in Korea.

A comparison of three column agglutination tests for red blood cell alloantibody identification

Objective

Commercial kits of column tests for pre-transfusion testing have progressively replaced conventional tube tests in most laboratories. Aim of this study was to compare three commercial test cell panels for the identification of irregular red blood cell (RBC) alloantibodies. Overall, 44 samples with a positive indirect antiglobulin test (IAT) by routine testing were used for comparison of following panels: Ortho RESOLVE^® panelC (Ortho Clinical Diagnostics (OCD), Milan, Italy), ID-DiaPanel(-P) (Bio-Rad Laboratories, CA, USA) and Identisera Diana(P) (Grifols, Barcelona, Spain). Column agglutination techniques were used, with microtubes containing either microgel (Bio-Rad/Grifols) or glass bead microparticles (Ortho).

Results

Alloantibody identification was possible in 38 samples, of which identical identification was shown in 33 samples by all methods. The remaining samples showed differences between certain methods, with the gel card system being superior to the glass card system for analyzing stored samples Considering that not all samples were evaluated in all three methods, the concordance rate reached 100% between Bio-Rad and Grifols, 90.5% between Bio-Rad and OCD, 86.5% between OCD and Grifols and 90.5% between all methods. Although differences in sensitivities were seen for specific antibodies, the three methods showed comparable performance for the identification of RBC alloantibodies.

Performance and reliability of a benchtop automated instrument for transfusion testing: a comparative multicenter clinical study in the US population

BACKGROUND

Heavy workload in hospital transfusion services and blood centers necessitates the implementation of automated platforms. We evaluated the performance of Erytra Eflexis (Diagnostic Grifols), a recently developed midsize automated instrument for pretransfusion testing, in comparison with a US Food and Drug Administration (FDA)-cleared device (Erytra). Reproducibility and repeatability of the results were also investigated.

STUDY DESIGN AND METHODS

Studies were conducted using the same card technology and reagents at three US sites. Tests were performed on 9174 specimens from hospital patients (55.61%) and blood donors (43.39%). Evaluations included 18,413 ABO/D/reverse typing; 9084 Rh phenotypes, 4640 K phenotypes, 2052 antibody screenings, 1232 antibody identifications, 469 direct antiglobulin tests, 612 IgG crossmatches, and 700 ABO-compatibility crossmatches. A reference blood panel was also sent to each center, for a total of 3900 replicate tests. Concordance between results with the two instruments and performance among the different centers were statistically evaluated.

RESULTS

Agreement between instruments was 99.84% for 37,202 test results, with 61 discrepancies (0.16%). Percentages of positive and negative agreement were 99.82% and 99.85%, respectively. No discrepancies were observed in 12,276 tests for direct ABO/D grouping. Discrepancies were observed during antibody identification (n = 19), antibody screening (n = 15), and reverse grouping (n = 10). Investigations of the discrepancies were resolved in favor of the study instrument in 55.73% of the cases. Erytra Eflexis obtained the expected results in the reproducibility analysis.

CONCLUSION

This multicenter study demonstrates that Erytra Eflexis with its gel card technology and reagents is reliable and substantially equivalent to the FDA-cleared instrument used as the reference.

Multicentre evaluation of Erytra Eflexis®, a benchtop fully automated analyser with a compact design for routine use in blood transfusion laboratory

OBJECTIVES

Evaluation of the compact benchtop Erytra Eflexis® automated analyser was performed at three health centres representing a range of routine transfusion workload.

BACKGROUND

Automation instruments with the simplicity and flexibility adequate for small- to mid-sized blood transfusion services are an unmet need.

METHODS

Performance in pre-transfusion testing (2109 ABO/D, 382 Rh/K phenotype, 2001 antibody screening, 113 antibody identification, 151 DAT, 88 extended phenotype; 655 cross matching) in comparison to Erytra® as reference device was assessed. Throughput [time to first result (TTFR), final turn-around time (TAT), processing rate] was calculated; usability and adaptability in laboratory practice under routine and with emergency samples were surveyed.

RESULTS

Agreement between systems was 99·8% (11/5499 test discrepancies, all due to weak/doubtful positive reactions). Erytra Eflexis produced six true positives (two Rh/D, two B positives, two screening), four false positives (three screening and one cross matching) and one false negative (screening). Processing of eight routine samples with the Erytra Eflexis for ABO/Rh(D) and screening took 34-38 min and 32-37 min, respectively, independent of the simultaneous processing of a STAT sample, whether or not the incubator for STAT was reserved. In this scenario, a STAT sample requested within 2 min after the routine load was processed in 14-26 min. Processing rate tended to stabilise and optimise in the larger workloads, particularly in ABO/Rh(D)/K cards (16·7, 18 and 19·5 results/h for 10, 15 and 24 specimens, respectively).

CONCLUSION

Erytra Eflexis analyser was found to be reliable and suitable for pre-transfusion routine tests performed in a small-/medium-sized blood transfusion laboratory.

Performance Evaluation of Automated Immunohematology Analyzer IH-500 for Blood Bank Testing

The automated immunohematology analyzer IH-500 (Bio-rad, Cressier FR, Switzerland) was developed recently for blood bank tests and this study evaluated performance of IH-500. 200 blood samples for ABO/Rh typing were collected. ABO/Rh typing results measured by IH-500 was compared with conventional manual methods. Antibody screening tests were performed with 100 samples using both IH-500 and the Ortho BioVue System, and results were compared. Antibody identification tests were conducted on 5 samples using both IH-500 and the Ortho BioVue System and results were compared. Crossmatching was performed with both IH-500 and conventional manual tube method using 4 patient serum samples and 10 blood cell donors, and 40 results were compared. Isoagglutinin titer of anti-A and anti-B was determined in 10 samples using both IH-500 and the automated analyzer Ortho AutoVue Innova and concordance rates were obtained. The concordance rates of ABO/Rh typing, antibody screening test, antibody identification test, and crossmatching between comparative manual methods and the IH-500 were all 100%. In the evaluation of isoagglutinin titer, 8 (80.0%) results out of 10 samples (80%) showed results within ± 1 titer between the IH-500 and the AutoVue Innova, which indicates the concordance rates of 80.0%. IH-500 reported results with two titers lower than Ortho AutoVue Innova in two samples. The IH-500 demonstrated good concordance rates and provided reliable results compared to comparative manual methods in the blood bank testing. IH-500 would be useful as a possible replacement for conventionally performed manual methods in blood bank testing.

Multicentre evaluation of the new ORTHO VISION® analyser

BACKGROUND

Implementation of fully automated analysers has become a crucial security step in the blood bank; it reduces human errors, allows standardisation and improves turnaround time (TAT).

OBJECTIVES

We aimed at evaluating the ease of use and the efficiency of the ORTHO VISION® Analyser (VISION) in comparison to the ORTHO AutoVue® Innova System (AutoVue) in six different laboratories.

METHODS

After initial training and system configuration, VISION was used in parallel to AutoVue following the daily workload, both automates being based on ORTHO BioVue® System column agglutination technology. Each participating laboratory provided data and scored the training, system configuration, quality control, maintenance and system efficiency. A total of 1049 individual samples were run: 266 forward and reverse grouping and antibody screens with 10 urgent samples, 473 ABD forward grouping and antibody screens with 22 urgent samples, 160 ABD forward grouping, 42 antibody screens and a series of 108 specific case profiles.

RESULTS

The VISION instrument was more rapid than the AutoVue with a mean performing test time of 27·9 min compared to 36 min; for various test type comparisons, the TAT data obtained from VISION was shorter than that from AutoVue. Moreover, VISION analysed urgent STAT samples faster. Regarding the ease of use, VISION was intuitive and user friendly.

CONCLUSIONS

VISION is a robust, reproducible system performing the most types of analytical determinations needed for pre-transfusion testing today, thus accommodating a wide range of clinical needs. VISION brings appreciated new features that could further secure blood transfusions.

Comparative Analysis of Clinical Samples Showing Weak Serum Reaction on AutoVue System Causing ABO Blood Typing Discrepancies

Background

ABO blood typing in pre-transfusion testing is a major component of the high workload in blood banks that therefore requires automation. We often experienced discrepant results from an automated system, especially weak serum reactions. We evaluated the discrepant results by the reference manual method to confirm ABO blood typing.

Methods

In total, 13,113 blood samples were tested with the AutoVue system; all samples were run in parallel with the reference manual method according to the laboratory protocol.

Results

The AutoVue system confirmed ABO blood typing of 12,816 samples (97.7%), and these results were concordant with those of the manual method. The remaining 297 samples (2.3%) showed discrepant results in the AutoVue system and were confirmed by the manual method. The discrepant results involved weak serum reactions (<2+ reaction grade), extra serum reactions, samples from patients who had received stem cell transplants, ABO subgroups, and specific system error messages. Among the 98 samples showing ≤1+ reaction grade in the AutoVue system, 70 samples (71.4%) showed a normal serum reaction (≥2+ reaction grade) with the manual method, and 28 samples (28.6%) showed weak serum reaction in both methods.

Conclusions

ABO blood tying of 97.7% samples could be confirmed by the AutoVue system and a small proportion (2.3%) needed to be re-evaluated by the manual method. Samples with a 2+ reaction grade in serum typing do not need to be evaluated manually, while those with ≤1+ reaction grade do.

A multicenter study on the performance of a fully automated, walk-away high-throughput analyzer for pretransfusion testing in the US population

BACKGROUND

Moving to automation is a major focus of transfusion centers. Erytra (Grifols) is a walk-away analyzer with high-performance and -throughput capacity for pretransfusion testing. Efficiency and performance of Erytra with its cards and reagents were evaluated in comparison to Food and Drug Administration (FDA)-approved reference methods.

STUDY DESIGN AND METHODS

A total of 5279 blood samples (46% patients; 54% donors) were obtained from US blood establishment facilities. Samples were analyzed with Erytra and results were compared with the routine FDA-licensed automated platforms used by the clinical study sites. A total of 25,217 tests were performed (15,322 ABO/D/reverse typing; 4916 Rh phenotypes, 669 K typing, 838 antibody screens, 759 antibody identifications, 250 cross-matches, 244 ABO compatibilities by immediate-spin cross-match, and 219 direct antiglobulin tests [DATs]).

RESULTS

Global agreement between Erytra and the comparison platforms was 99.66%, with 99.82% positive percent agreement (95% lower confidence bound [LCB], 99.75%) and 99.50% negative percent agreement (95% LCB, 99.37%). There were 85 discrepancies (0.34%), including cross-matches (n = 13), antibody screens (n = 10), antibody identifications (n = 21), and DATs (n = 5), whereas an excellent concordance was obtained in blood grouping determinations (ABO/D/C/E/c/e/K, 0.04%-0.22% discrepancies). Analysis of the discrepancies showed that Erytra provided the correct result in 51 of them (60%), with only five false negatives (one O patient transplanted with A, one mixed-field reaction in a very weak D, one anti-Vel, two A2rr). Erytra results were 100% reproducible in a series of 3760 repetition tests.

CONCLUSION

Grifols' Erytra analyzer showed reliable efficacy compared with equivalent FDA-licensed reagents and FDA-cleared instruments.

Evaluation of Erytra® fully automated analyser for Routine Use in Transfusion Laboratory

OBJECTIVE

To evaluate efficiency and performance of Erytra® analyser in comparison to the reference platform of the NBT immunohaematology laboratory (Bio-Rad ID-System).

BACKGROUND

Moving to automation or semi-automation is a major focus of transfusion centres. The Erytra® (Grifols) is a new fully automated walk-away analyser with high volume processing capacity for pre-transfusion testing, designed to be used with the unique 8-column DG Gel® cards.

STUDY DESIGN AND METHODS

A total of 2201 immunohaematological tests (1041 ABO/D grouping, 1041 antibody screening, 51 antibody identification, 45 newborns (ABO/D and DAT) and 23 crossmatches were performed on 1160 donor/patient whole blood samples. Erytra®'s performance was assessed by means of a stress test replicating the routine work of a hospital laboratory.

RESULTS

Concordant results between the Erytra® and the reference method were obtained in 2195 (99·73 %) of the tests. There were only three discrepancies out of 6246 reactions (0·05%) in ABO/D grouping, all in the reverse group which did not mislead to group identification. Of the 1041 samples screened for antibody presence, Erytra® detected all the relevant antibodies [9 not detected weak prophylactic anti-D were determined to be clinically nonsignificant (<0·1 IU mL(-1) )] while Bio-Rad ID-System missed one anti-e and one anti-Jk(a) . Concordance for D grouping, crossmatching and newborns was 100%. Results of the simulated stress test exercise highlighted the capacity of Erytra® for absorbing into 4 h workloads equivalent to 24 h of routine.

CONCLUSIONS

Grifols' Erytra® analyser showed reliable high sensitivity, velocity and capacity to cope with high workload in the immunohaematology laboratory routine.