This could explain why in pregnancy I was tested as o negative and was given anti D shots but tested o positive this week after donating blood for the first time. I wish they had told me this was the case though instead of me wondering how my blood went from o neg to o pos in the last year!
False positive because the cells used for the test are already coated with IgG antibodies "In-vivo". The IgG antibodies that are already attached to the cells will react with the Anti-IgG (AHG) that is added to the tube. Your weak D and D control will both be positive if the DAT (Direct antiglobulin test) is positive.
Medical Lab Lady Gill a mother gave birth and was an RhIg Candidate and was typed O, D-negative. Cord blood was taken for ABO, Rh, & DAT. Cord blood was A neg, weak D positive, but was also DAT positive so they reported the type as "unknown". The med tech knows that the test for weak D could not be reported on the presence of a positive DAT.
Frank Harold I cannot help you cheat on a test. With that being said, I will answer the question. If the mother was given the RhIg, the positive DAT may be due to the medication and not the mother making Ab to the baby's cell Ag.
This could explain why in pregnancy I was tested as o negative and was given anti D shots but tested o positive this week after donating blood for the first time. I wish they had told me this was the case though instead of me wondering how my blood went from o neg to o pos in the last year!
I have a question please you said if u have a positive DAT and you did this test you will get false positive, why? What’s the correlation?
False positive because the cells used for the test are already coated with IgG antibodies "In-vivo". The IgG antibodies that are already attached to the cells will react with the Anti-IgG (AHG) that is added to the tube. Your weak D and D control will both be positive if the DAT (Direct antiglobulin test) is positive.
Why can't a weak D cord blood sample be reported in the presence of a positive DAT result?
Frank Harold
I'm not sure I understand what you're asking. Can you please elaborate about the scenario?
Medical Lab Lady Gill a mother gave birth and was an RhIg Candidate and was typed O, D-negative. Cord blood was taken for ABO, Rh, & DAT. Cord blood was A neg, weak D positive, but was also DAT positive so they reported the type as "unknown". The med tech knows that the test for weak D could not be reported on the presence of a positive DAT.
Medical Lab Lady Gill just got this from a case given to us by our professor. I hope you can help me! 😌
Frank Harold
I cannot help you cheat on a test.
With that being said, I will answer the question. If the mother was given the RhIg, the positive DAT may be due to the medication and not the mother making Ab to the baby's cell Ag.
Frank Harold
The best thing to do with this type of patient would to get a heel stick from the baby to confirm the testing. ☺
She talk too much
Ok keyboard warrior