RichU

Thanks for still cogitating on this. How strong would an antibody have to be to block antigen sites? ( Difficult to answer given the lack of cases, I assume) Also, given the presumed whoppingness(!) of the titre, wouldn't you expect at least some sign of HDFN? Cheers p.s. I have had to postpone the presentation due to circumstances beyond even World leaders.

There's always a caveat with serology! Sometimes when things are so ingrained it's easy to take them as read.

Sorry, it's not that I don't recognise the significance of a titre of 32, just that I wished to illustrate that a rising titre is significant during any pregnancy but if you don't do any titrations, due to detecting an antibody in a previous pregnancy, how would you pick it up?

I always understood it was the change (especially upwards trend) in titre throughout pregnancy which indicated whether there might be a problem for the current fetus (and likely antigen status) rather than just a historic or latest result. A change of titre from 2 to 32 is more alarming than a titre which is 32 at booking but remains at 32.

Forgot to mention that all our transfusion lab samples must be handwritten at the bedside with no amendments or missing details and signed/dated/timed with matching printed form. As you can imagine we reject lots of samples.

We always require a second confirmatory sample before issuing group specific units if there is no historical group. We request this as soon as we know the patient has not been seen by us before. This doesn't impact on the speed of providing cross matched blood due to the shorter test time for a forward group compared to a full group, antibody screen and cross match. The units are selected based on a rapid tube spin group and set up with the first sample group and screen. We do not do electronic issue for any patients.

As an island with a small population and limited opportunity for Blood product deliveries, we only tend to keep group A platelets (high titre anti-B negative). We do require a group result either as a current case or historical. For planned transfusions most patients get the group A (trauma) stock unless their count doesn't increment with non-group specific. "The expiration date of the specimen does not apply to non RBC containing blood products, so as long as the patient is wearing the corresponding BB Band, we will issue Plasma, Platelets and/or Cryo." Joanne P Scannell With regards to platelets being free of red cells - we give IgG anti-D to females <50 years old who are RhD - but get RhD+ platelets

Hi Arno, I am unsure about this. Why might she have been given IVIG and what effect could this have on the serology? Cheers, Rich

Again thank you. The phenotype is probably R1R2 which is why I opted for anti-f and not anti-c. No transfusion history. The second pregnancy delivered in March 2018. We had no sample after her 28 week routine A/N in Dec '17. The booking sample in which we found anti-f was in June '19 (approx 10 week gestation) The woman's partner in the latest pregnancy is K- but we know how much store to set by that! I will go with this. Rich

Thanks. I did hypothesise that stimulation of her immune system by current pregnancy triggered production of antibodies made in response to previous baby which were sub detectable at booking. ie. Patient made anti-f, anti-K and anti-Fya when previously pregnant, current fetus (f+, K-, Fya-) lead to stimulation and increase in production of all 3 antibodies by general triggering of immune system. Not sure if this occurs and didn't want to float that idea straight away. Rich

Unofficially! IAT gelcard. Result 1+ was weaker than DAT 2+ and control Fya+b+ cell 4+. Even though Fya type not valid the K antigen type is.

I HAVE REPOSTED THIS IN THE IMMUNOHAEMATOLOGY FORUM.

I PUT THIS Q IN TRANSFUSION SECTION BUT I GUESS MORE RELEVANT HERE. We recently had an antenatal case which showed some unusual features. This was the third pregnancy, the first miscarried at less than 10 weeks. The second was delivered after a seemingly uneventful pregnancy. At booking we found enzyme anti-f. At 28 weeks anti-f, anti-K and a further unidentified Ab. (f and K enzyme only). By 32 weeks She also had anti-Fya and possibly Cw. From 38 weeks gestation we kept 4 R1R1 K- Fya- units crossmatched in case of emergency. These were compatible. 4 days later the sample had a positive DAT and all units were incompatible. The patient delivered before we could get the sample referred to the NHSBT lab in the UK. The baby typed as R1r K-. The baby had a weak positive DAT so Fya antigen typing was not officially performed ( I did the test and am certain It was Fya-) So, my questions are; How can the anti-K and anti-Fya be stimulated by this fetus? Has anyone else seen this happen? I was hoping to present a simple(ish) talk on anti-f to the multi-disciplinary on-call team at my hospital but don't want to scare them! Thanks, Rich

We recently had an antenatal case which showed some unusual features. This was the third pregnancy, the first miscarried at less than 10 weeks. The second was delivered after a seemingly uneventful pregnancy. At booking we found enzyme anti-f. At 28 weeks anti-f, anti-K and a further unidentified Ab. (f and K enzyme only). By 32 weeks She also had anti-Fya and possibly Cw. From 38 weeks gestation we kept 4 R1R1 K- Fya- units crossmatched in case of emergency. These were compatible. 4 days later the sample had a positive DAT and all units were incompatible. The patient delivered before we could get the sample referred to the NHSBT lab in the UK. The baby typed as R1r K-. The baby had a weak positive DAT so Fya antigen typing was not officially performed ( I did the test and am certain It was Fya-) So, my questions are; How can the anti-K and anti-Fya be stimulated by this fetus? Has anyone else seen this happen? I was hoping to present a simple(ish) talk on anti-f to the multi-disciplinary on-call team at my hospital but don't want to scare them! Thanks, Rich