Tabbie Posted July 12, 2016 Share Posted July 12, 2016 Hi Everyone I am currently studying and decided to do some ABO experiments with patient samples but with some odd results. Wondering if anyone could shed some light ? I cross matched a mix of incompatible red cells with patients plasma to see if there would be a difference in strength of ABO incompatibility. The AB and B red cells with the group A plasma gave negative results ? AB red cells with group B plasma was positive I.e. a group B patient being cross matched with AB red cells All samples were Rh D positive to avoid any incompatibility with that issue. I also repeated them with the same samples and got the same results. Thanks Moira Link to comment Share on other sites More sharing options...
gagpinks Posted July 12, 2016 Share Posted July 12, 2016 Did you incubate at 37? Did you consider clinical conditions? Link to comment Share on other sites More sharing options...
Tabbie Posted July 12, 2016 Author Share Posted July 12, 2016 Yes 37 incubation an patients I selected just pre op samples previously tested nothing out of ordinary ? Link to comment Share on other sites More sharing options...
Malcolm Needs ☆ Posted July 13, 2016 Share Posted July 13, 2016 Would you mind telling us what technology you were using (tubes, column agglutination technology, solid phase. etc)? Link to comment Share on other sites More sharing options...
yeleng22 Posted July 13, 2016 Share Posted July 13, 2016 (edited) Human Anti-A typically have a high titer as where Anti-B are usually weaker. Correct me if wrong, but I believe this is the reason for allowing GroupA plasma usage for emergency massive transfusion for most trauma hospitals now. Big AABB article sometimes in the end of 14' or early 15' about this. Edited July 13, 2016 by yeleng22 MTP added Yanxia 1 Link to comment Share on other sites More sharing options...
Tabbie Posted July 13, 2016 Author Share Posted July 13, 2016 Hi Malcolm CAT. I repeated with positive result. Sample I remixed and centrifuged an tested again when at room temperature. ? Anti-HI cold sample issue ? Or Secretor rule ? Will read more on that topic yeleng 22 Thanks for feedback Malcolm Needs 1 Link to comment Share on other sites More sharing options...
mrmic Posted August 2, 2017 Share Posted August 2, 2017 sugar sugar Link to comment Share on other sites More sharing options...
Cliff Posted August 4, 2017 Share Posted August 4, 2017 On 8/2/2017 at 3:03 PM, mrmic said: sugar sugar ? Link to comment Share on other sites More sharing options...
mrmic Posted August 4, 2017 Share Posted August 4, 2017 ABO antigens are basically sugars structures. The development and expression of these antigens and antibodies are controlled by various genes an individual inherits. The antibodies are also possibly produced based on the various "natural" exposures to similar antigens in the environment, gut, etc. and the immune system functionality of the antibody producer. (or in the case of commercial antisera, the particular antibody producer(s) or cell line(s) used to produce the antibody can vary from manufacturer to manufacturer). Actually, as I ponder this, maybe all antigens/antibodies are effected by some of the same processes...... Therefore, in my humble opinion, the strengths of the agglutination reaction within in any one test method, maybe affected by these factors as well as the method itself. If everyone was group O it would be nice for Blood Bank ................. but what's the adventure in that? Variety is the spice of life! BldBnker 1 Link to comment Share on other sites More sharing options...
Neil Blumberg Posted August 7, 2017 Share Posted August 7, 2017 Some individuals have very low titer/affinity antibodies, and this probably explains your negative results. Not all that surprising or uncommon. AuntiS and mrmic 2 Link to comment Share on other sites More sharing options...
Neil Blumberg Posted August 7, 2017 Share Posted August 7, 2017 Not mention that isoagglutinins may be absent entirely in the first half year to year of life, and in patients receiving intensive immunosuppressive/myeloablative therapy. So the source of your plasma may make a difference, if it was from patients in a hospital, as opposed to healthy blood donors. mrmic, Yanxia and AuntiS 3 Link to comment Share on other sites More sharing options...
Mabel Adams Posted August 8, 2017 Share Posted August 8, 2017 Another reason why our computers are better at selecting ABO compatible units than serological testing is. mrmic, MaryPDX, AuntiS and 5 others 8 Link to comment Share on other sites More sharing options...
Malcolm Needs ☆ Posted August 9, 2017 Share Posted August 9, 2017 11 hours ago, Mabel Adams said: Another reason why our computers are better at selecting ABO compatible units than serological testing is. Just SO true Mabel. Link to comment Share on other sites More sharing options...
R1R2 Posted January 10, 2018 Share Posted January 10, 2018 Don't know if someone mentioned this idea earlier, but did you try serum? Reactions may be inhibited or weak if using EDTA plasma. Link to comment Share on other sites More sharing options...
Yanxia Posted January 11, 2018 Share Posted January 11, 2018 14 hours ago, R1R2 said: Don't know if someone mentioned this idea earlier, but did you try serum? Reactions may be inhibited or weak if using EDTA plasma. Would you explain this please? Thanks Link to comment Share on other sites More sharing options...
Malcolm Needs ☆ Posted January 11, 2018 Share Posted January 11, 2018 It is because serum would have Ca++, Mg++ and Mn++ ions present (needed to activate the classical complement pathway beyond initiation), whereas EDTA will, in effect, remove these ions from plasma by chelation. An ABO mis-match is far "easier" to detect using serum than plasma, and may even lead to haemolysis of the test cells, however, in both cases, IF the plasma of the proposed recipient has high levels of Type 1 ABO antigen (the ABO substance that is soluble in the plasma/serum - in other words the proposed recipient is a "strong secretor"), there is a slight danger, albeit slight, that this ABO substance may inhibit the reagent anti-A and/or anti-B, causing false negative results. exlimey and Yanxia 2 Link to comment Share on other sites More sharing options...
R1R2 Posted January 11, 2018 Share Posted January 11, 2018 6 hours ago, Malcolm Needs said: It is because serum would have Ca++, Mg++ and Mn++ ions present (needed to activate the classical complement pathway beyond initiation), whereas EDTA will, in effect, remove these ions from plasma by chelation. An ABO mis-match is far "easier" to detect using serum than plasma, and may even lead to haemolysis of the test cells, however, in both cases, IF the plasma of the proposed recipient has high levels of Type 1 ABO antigen (the ABO substance that is soluble in the plasma/serum - in other words the proposed recipient is a "strong secretor"), there is a slight danger, albeit slight, that this ABO substance may inhibit the reagent anti-A and/or anti-B, causing false negative results. Yes, what he said..... Malcolm Needs 1 Link to comment Share on other sites More sharing options...
SMILLER Posted January 11, 2018 Share Posted January 11, 2018 It's one of the reasons that washing patient cells before testing is one of the steps in resolving an ABO discrepancy. Scott Malcolm Needs 1 Link to comment Share on other sites More sharing options...
Malcolm Needs ☆ Posted January 11, 2018 Share Posted January 11, 2018 21 minutes ago, SMILLER said: It's one of the reasons that washing patient cells before testing is one of the steps in resolving an ABO discrepancy. Scott Absolutely right Scott. Link to comment Share on other sites More sharing options...
Yanxia Posted January 12, 2018 Share Posted January 12, 2018 On 2018/1/11 at 3:30 PM, Malcolm Needs said: It is because serum would have Ca++, Mg++ and Mn++ ions present (needed to activate the classical complement pathway beyond initiation), whereas EDTA will, in effect, remove these ions from plasma by chelation. An ABO mis-match is far "easier" to detect using serum than plasma, and may even lead to haemolysis of the test cells, however, in both cases, IF the plasma of the proposed recipient has high levels of Type 1 ABO antigen (the ABO substance that is soluble in the plasma/serum - in other words the proposed recipient is a "strong secretor"), there is a slight danger, albeit slight, that this ABO substance may inhibit the reagent anti-A and/or anti-B, causing false negative results. Thank you very much for the explanation. Just a little confusion how do the Ca++, Mg++ and Mn++ ions infect the agglutination? does it because the complements can enhance agglutination or because the complements caused haemolysis is a sign of ABO mis-match? Link to comment Share on other sites More sharing options...
Malcolm Needs ☆ Posted January 12, 2018 Share Posted January 12, 2018 It is the latter yan xia. The various metal ions have no effect on either sensitisation or agglutination, but, are vital co-factors for the complete initiation of the classical complement pathway (C1qrs), leading to the membrane attack complex (MAC), and it is this MAC that allows haemolysis to take place, and it is this haemolysis that allows the Hb to escape from the red cells, which we see as a pink/red colour in our tests, which equates to a positive result. As the classical complement pathway is a huge amplification system (one C1qrs complex, for example, results in the generation of some 8, 000 C3b molecules), it makes the test very sensitive indeed - much more so than just looking for agglutination. rravkin@aol.com, Yanxia and Tabbie 2 1 Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now