Overview, History, Evaluation and Future Developments of the AutoGrouper 16-C

Evaluation of a new automated instrument for pretransfusion testing

BACKGROUND

A number of automated devices for pretransfusion testing have recently become available. This study evaluated a fully automated device based on column agglutination technology (AutoVue System, Ortho, Raritan, NJ).

STUDY DESIGN AND METHODS

Some 6747 tests including forward and reverse ABO group, Rh type and phenotype, antibody screen, autocontrol, and crossmatch were performed on random samples from 1069 blood donors, 2063 patients, and 98 newborns and cord blood. Also tested were samples from 168 immunized patients and 53 donors expressing weak or variant A and D antigens. Test results and technician times required for their performance were compared with those obtained by standard methods (manual column agglutination technology, slide, semiautomatic handler).

RESULTS

No erroneous conclusions were found in regard to the 5028 ABO group and Rh type or phenotype determinations carried out with the device. The device rejected 1.53 percent of tests for sample inadequacy. Of the remaining 18 tests with discrepant results found with the device and not confirmed with the standard methods, 6 gave such results because of mixed-field reactions, 10 gave negative results with A2 RBCs in reverse ABO grouping, and 2 gave very weak positive reactions in antibody screening and crossmatching. In the samples from immunized patients, the device missed one weak anti-K, whereas standard methods missed five weak antibodies. In addition, 48, 34, and 31 of the 53 weak or variant antigens were detected by the device, the slide method, and the semiautomated handler, respectively. Technician time with the standard methods was 1.6 to 7 times higher than that with the device.

CONCLUSION

The technical performance of the device compared favorably with that of standard methods, with a number of advantages, including in particular the saving of technician time. Sample inadequacy was the most common cause of discrepancy, which suggests that standardization of sample collection can further improve the performance of the device.

Trial of ABO and Rh blood typing with an automated blood cell counter

We designed a method for ABO and Rh typing using a blood cell counter. Blood specimens were diluted with physiological saline, mixed with an antiserum, and incubated. The cell count and size distribution curves were obtained by an automated blood cell counter. The samples with agglutination had a decreased cell count and a characteristic size distribution curve with a population of doublet cells on the right side. The results were correlated with the degree of agglutination observed by the manual method, used as a reference. It should be possible to adapt blood cell counters for use in blood typing.

The evolution of pretransfusion testing: from agglutination to solid-phase red cell adherence tests

Hospital transfusion services and blood centers still use manual hemagglutination tests for most of their serological procedures. Automation of hemagglutination reactions has proven to be difficult, primarily because hemagglutination lacks an objective endpoint which can be easily interpreted by inexpensive instruments. Alternatively, solid-phase red cell adherence assays for ABO cell and serum grouping, Rh typing, red cell and platelet antibody screening, red cell and platelet crossmatching, IgA deficiency screening, hepatitis B surface antigen, and HIV antibody screening have been developed. The performance of these assays compares favorably with current hemagglutination and enzyme immunoassay methods. All of these tests share a common objective endpoint of adherence or nonadherence of indicator red cells. This uniformity allows easy interpretation of results visually, spectrophotometrically, or by image analysis. The latter technique has the potential to revolutionize the reading and interpretation of all agglutination tests. Solid-phase red cell adherence tests in microplates are ideal for batch processing large numbers of specimens. However, adherence tests are not restricted to this format. Therefore, blood grouping dipsticks have been produced, which permit testing of individual blood samples even outside of the laboratory.

Blood grouping with the Olympus PK7100 testing system

The Olympus PK7100, an automated microtitre blood typing machine, identifies, aliquots, and dilutes samples, adds reagents, photometrically detects agglutination, and records reaction results, with a throughput of 240 samples/h. A total of 20,147 donors was tested in parallel with the Groupamatic 360. Of these, 207 could not be ABO typed after two runs. Three samples typed as B by the Olympus were found to be A2B. Seventy-seven could not be typed for D after two runs. Of these, 55 were Rh positive and 22 negative. The Olympus identified 37 of 48 Du positive samples as Rh positive, while it typed three as Rh negative, and eight as 'uncertain'. None of these samples was identified as Rh positive by the Groupmatic 360. The Olympus PK7100 is accurate, reliable, easy to operate, and capable of high throughput with minimal operator intervention.

Considerations in the use of laboratory robots: aspects of safety and accuracy

A general-purpose laboratory robot was configured to prepare blood samples for the HBsAg and anti-HIV tests. Several issues were studied in order to eliminate problems and optimize the system. These included pipetting accuracy, intersample carryover, reagent interference, splashing and aerosol generation and user-related issues. A number of general guidelines were developed to assist others in developing and implementing systems for this and similar applications.

Solid-phase techniques in blood transfusion serology

For nearly a century, erythrocyte agglutination has persisted as the most widely used method for the demonstration of antigen-antibody reaction in immunohematology. So far, no other system has been developed which can match its simplicity, versatility, and general reliability. The major disadvantage of agglutination reactions is the lack of an objective endpoint, which has severely hindered attempts to automate routine pretransfusion tests. To overcome this problem, we have designed a series of solid-phase assays for ABO and Rh grouping, antibody screening, compatibility, and hepatitis tests. Each of these solid-phase assays shares a common endpoint of red cell adherence, which is easily interpreted visually or spectrophotometrically. Computer interface permits the automatic interpretation and recording of results. We believe this solid-phase system should finally bring the blood bank laboratory into the age of automation.

Automated determination of ABO/Rh in microplates

A semi-automated system for determining the ABO group and Rh type of blood samples has been developed using a commercially available automated microplate (ELISA) reader and a microcomputer. Optimization of serologic, measurement and interpretation parameters was accomplished without significantly changing an existing manual procedure. The first pass noninterpretation rate of this system in the laboratory prior to field trials is 7.1%. A commercial system of this type should be cost-effective as a primary instrument for small to medium sized blood centers and transfusion services.