B Wattar | PubMed Health

PubMed1982

[Automated screening and identification of irregular anti-erythrocyte antibodies].

Screening of irregular antibodies performed on a Groupamatic MG50, a two or three channels auto-analyser, and with manual techniques, revealed 4,445 positive sera which were than identified on this auto-analyser system. It was concluded that the "saline-PVP-4 degrees C" channel recovers 17% of the screened sera, which appeared negative with the bromelin and polybrene channels. Saline -4 degrees C detected sera include all of the -M and -P1 specificities and about half of the -K, -Lea and Leb. Identification of cold and namely anti-I antibodies on this channel also leads to an improved analysis of polyspecific sera. The high sensitivity of this 3 channels auto-analyser seems to be optimal for screening and identification of irregular antibodies.

Antibody Specificity↗

PubMed1982

Automation of cross-matching and red cell antibody screening.

This automatic system combines the major cross-match with screening for allo- and autoantibodies. Moreover, the detected antibodies can be identified on a panel of frozen and thawed red blood cells (RBC). The system is made up of two connected samplers, three channels working, respectively, with bromelin PVP, LISP and saline PVP at 4 degrees C, three colorimeters or three red cell autocounters and their recorders. The optimal speed is 50 samples/h and one whole test requires 19 min. Our experience indicates that this automatic system is appreciably more sensitive and much more rapid and efficient than manual techniques. In spite of increased sensitivity, the ratio of rejected bags does not exceed 2.7%.

Autoantibodies↗

PubMed1975

[Automatic pre-transfusion serology].

This paper describes an automated apparatus combining Rosenfield's and Lalezari's antibody screening and identification basic technics. PVP bromelin and low ionic strength acid polybren channels are used; agglutinates are decanded; the remaining cells are hemolyzed and the optical density is then measured through a colorimeter and recorded on a chart; speed is of 40 samples an hour. This machine was also used for irregular antibody screening and identification. Sensitivity is shown to be equal to that of manual technics for ABO, Lewis, Lutheran as well as K, S, M, Kpb, Xga, U and Vel antibodies detection. Nevertheless, a much greater sensitivity is achieved (titers 3 to 10 times higher) than by manual technics for Rh, -k, S, Fya antibodies detection. Polybren channel is suitable for anti-Rh, Duffy, I and M (human detection; bromelin channel however, has a greater sensitivity for other specificities. Anti-M and anti-N sera from rabbits were shown to be non specific when using this machine. Over almost 15 000 sera tested, no antibody (detected by manual techniques) escaped the automated screening. This antibody detection machine was applied to compatibility tests prior to transfusion. (21 480 units were tested. aimed to be transfused to 5 611 patients). A third, PVP without bromelin, was set in parallel in order not to let escape any anti-M, even a weak one. The sera distributor was slaved to the cells distributor so that the whole procedure was automated. Furthermore, each serum was tested against red cells to be transfused, but also against the patient's own red cells to be transfused, but also against the patient's own red cells and against two selected red cells panels, so as to ensure irregular antibody detection at the same time. Using this machine, 3 to 4% of the cell samples were rejected, i.e. more than with usual techniques. All manually detected antibodies were identified, but also some others, which showed only weak reactions by classical techniques. Total results can be obtained within 20 to 30 minutes, which is quite rapid, compared to techniques using for example antiglobulin tests.

Antibody Specificity↗