Comparison Between Conventional and Automated Techniques for Blood Grouping and Crossmatching: Experience from a Tertiary Care Centre

A Flow Cytometric Approach to Assess RBC-Bound IgG Antibodies in Different Age Populations

BACKGROUND

RBC-bound IgG antibody-mediated agglutination occurs when red blood cells (RBCs) cluster together due to the presence of antibodies or other contributing factors. This process could be favorable in the elderly population. Not only is it critical for blood typing procedures, but also plays a significant role in autoimmune hemolytic anemia, a condition characterized by escalated destruction of RBCs. Understanding these mechanisms are essential for precise diagnoses, ensuring the safety of blood transfusions, and facilitating laboratory testing protocols in clinical settings.

OBJECTIVE

This study explores to detect RBC-bound IgG antibodies in various age groups using flow cytometry method.

MATERIALS AND METHODS

A total of 120 Serum samples were taken from different age groups of healthy individuals. In addation, 30 samples were obtained from individuals with autoimmune diseases, and another 30 samples were collected from healthy elderly individuals of the same ages. Serum (100 μL) were added in eppendorf tube containing equal amount of normal saline and 50 μL of 2 % RBC, mixed well and then kept in water bath at 37 °C for 30 min. After incubation, antihuman globulin (AHG) was added and checked for the index of agglutination (IAG) using flow cytometry method. A control sample was also analyzed using the same method.

RESULTS

Flow cytometry analysis revealed significant differences in IAG between younger individuals and the elderly (P-value 0.003), demonstrating a positive linear relationship. Interestingly, no agglutination was observed in the younger group, whereas elderly healthy individuals exhibited agglutination. Furthermore, significant differences were found between autoimmune disease patients and elderly healthy individuals of the same age groups (P-value 0.0001), with strong IAG in autoimmune patients compared to relatively less agglutination in the elderly population.

CONCLUSION

Our study has successfully detected RBC-bound IgG antibodies in various age groups. Young age groups showed negative IAG while elderly individuals and patients with autoimmune diseases exhibited the presence of RBC-bound IgG antibodies.

Benefits of VISION Max automated cross-matching in comparison with manual cross-matching: A multidimensional analysis

BACKGROUND

VISION Max (Ortho-Clinical Diagnostics, Raritan, NJ, USA) is a newly introduced automated blood bank system. Cross-matching (XM) is an important test confirming safety by simulating reaction between packed Red Blood Cells (RBCs) and patient blood in vitro before transfusion. We assessed the benefits of VISION Max automated XM (A-XM) in comparison with those of manual XM (M-XM) by using multidimensional analysis (cost-effectiveness and quality improvement).

MATERIALS AND METHODS

In a total of 327 tests (130 patients), results from A-XM and M-XM were compared. We assessed the concordance rate, risk priority number (RPN), turnaround time, hands-on time, and the costs of both methods. We further simulated their annual effects based on 37,937 XM tests in 2018.

RESULTS

The concordance rate between A-XM and M-XM was 97.9% (320/327, kappa = 0.83), and the seven discordant results were incompatible for transfusion in A-XM, while compatible for transfusion in M-XM. None of the results was incompatible for transfusion in A-XM, while compatible for transfusion in M-XM, meaning A-XM detect agglutination more sensitively and consequently provides a more safe result than M-XM. A-XM was estimated to have a 6.3-fold lower risk (229 vs. 1,435 RPN), shorter turnaround time (19.1 vs. 23.3 min, P < 0.0001), shorter hands-on time (1.1 vs. 5.3 min, P < 0.0001), and lower costs per single test than M-XM (1.44 vs. 2.70 USD). A-XM permitted annual savings of 46 million RPN, 15.1 months of daytime workers' labor, and 47,042 USD compared with M-XM.

CONCLUSION

This is the first attempt to implement A-XM using VISION Max. VISION Max A-XM appears to be a safe, practical, and reliable alternative for pre-transfusion workflow with the potential to improve quality and cost-effectiveness in the blood bank.

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.

Multi-Center Evaluation of the Automated Immunohematology Instrument, the ORTHO VISION Analyzer

BACKGROUND

ORTHO VISION Analyzer (Vision), is an immunohematology instrument using ID-MT gel card technology with digital image processing. It has a continuous, random sample access with STAT priority processing. The efficiency and ease of operation of Vision was evaluated at 5 medical centers.

METHODS

De-identified patient samples were tested on the ORTHO ProVue Analyzer (ProVue) and repeated on the Vision mimicking the daily workload pattern. Turnaround times (TAT) were collected and compared. Operators rated key features of the analyzer on a scale of 1 to 5.

RESULTS

A total of 507 samples were tested on both instruments at the 5 trial sites. The mean TAT (SD) were 31.6 minutes (5.5) with Vision and 35.7 minutes (8.4) with ProVue, which renders a 12% reduction. Type and screens were performed on 381 samples; the mean TAT (SD) was 32.2 minutes (4.5) with Vision and 37.0 minutes (7.4) with ProVue. Antibody identification with eleven panel cells was performed on 134 samples on Vision; TAT (SD) was 43.2 minutes (8.3). The installation, training, configuration, maintenance and validation processes are all streamlined to provide a short implementation time. The average rating of main functions by the operators was 4.1 to 4.8. Opportunities for improvement, such as flexibility with editing QC results, maintenance schedule, and printing options were identified. The capabilities to perform serial dilutions, to accept pediatric tubes, and review results by e-Connectivity are enhancements over the ProVue.

CONCLUSIONS

Vision provides shorter TAT compared to ProVue. Every site described a positive experience using Vision.

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.