Hi,

We have a baby whose DAT is Pos, coated with maternal Anti -E.

Now, we need to perform xm using the mom's plasma to transfuse the baby. We have a mom's specimen which is 5 days old (expired specimen) drawn before the delivery.

Should we use the specimen for xm or do we need to draw a new specimen? Which one is the better choice?

Thanks.

Autumn

You need a specimen drawn after delivery which is less than 3 days old.

Autumn,

Bill's response is the standard thinking when working with inpatients however in this case the pre-delivery specimen would be the specimen that the fetus experienced prior to delivery and when performing the IgG xm, would promote a greater reactivity, if any, then the post specimen. If any products are needed for mom then a new specimen would be in order.

You may, however, need to consider the storage conditions your 5 day old sample was subjected to. Antibodies do weaken over time, particularly if the sample sits at room temperature as ours often do.

Is there any reason collecting a new sample from mom would not be a reasonable thing to do such as she has gone home and lives 1000 miles away? I can think of a few reasons the 5 day old sample would not be my first choice and they were mentioned above. I can think of no resons why I would hesitate to collect another sample from mom other than she is not available.

Is there anything wrong with actually using a sample from the baby (if there is enough plasma) rather than needing a sample from the mother?

When I was working in a pediatric BB we used samples collected directly from the baby. We did a type and screen and AHG (gel) crossmatch on the specimen and repeated this every 72 hours as long as the baby needed to be transfused.

AABB standards refer to using either the maternal or neonatal plasma - you can test neonate, then give units that either do not contain the corresponding antigen OR are compatible by AHG xm.

I would just give antigen negative units. Baby can't make his/her own antibody so if you've identified the anti-E in Mom, ruled out other antibodies and have proven that baby does have the passive Anti-E, my understanding is that you just have to give antigen negative units until the passive antibody is no longer demonstrable in baby's system, no need for any crossmatch. For an anti-E, I would probably just give E-negative units without/XM until the baby is 4 months old or no longer needs blood (which ever happens first) without repeating any tests to see if the Anti-E is still demonstrable; it doesn't hurt to give E-negative units even if the antibody is out of the baby's system.

We use the baby's blood unless it is impossible (or harmful) to obtain. We do one type and screen, identify the passively acquired antibody, then give antigen negative blood uncrossmatched. We do retest the baby every 7 days to see if the antibody is gone. Once the antibody is gone, we treat the baby like any other less than 4 month old.

I'm a bit uncomfortable with the term "passively acquired antibody", because amternal IgG antibody is actively transported across the placenta, and the concentration of maternal IgG antibody can be, and often is, pound for pound, great er in the baby than the mother. I much prefer the term "maternal antibody", BUT THEN, I AM KNOWN TO BE A PEDANT!!!!!!!!!!!!

I have more story on the baby. Yesterday, we were not able to collect a new sample from mom. She was discharged and not available. We transfused the baby with E neg unit that was xm'd with 5 days old mom's plasma (has been kept in a fridge). Today, we called mom back and collected a new sample. Her new sample shows an additional antibody; Anti-E and Jka now. She has not been transfused. At the time of her delivery, BK test was neg. I am not sure exactly at what stage the L&D draw the BK sample, but assume it was a pre delivery sample. No post partum BK test was done. So, we are going to transfuse the baby with E neg and Jka neg units from now on; xm'd with fresh mom's sample according to our SOP. Here is a my new question. Do we have to give a baby Jka neg unit although mom had only anti-E at delivery? If we decide not to give Jka neg unit, IgG xm with mom's sample would be positive.

Autumn.

Autumn,

In the pre-delivery specimen the Anti-Jka was at such a low concentration that it was not detectable through your testing procedure. Does that mean that there was not a significant enough concentration that crossed the placenta into the fetus? One of the previous posters described how the concentration of the antibody would be hire in the fetus. This stands to reason given that this is where the sensitizing antigen resides. So it is better to error on the side of caution and transfuse antigen negative PC's for this neonate especially in the absence of a direct specimen.

Autumn,

Is it not possible to test the baby's plasma for maternal antibodies? If there is no detectable antibody in baby's plasma you do not have to give antigen negative or crossmatched blood. What does your procedure/policy state?

JB

Autumn,

Is it not possible to test the baby's plasma for maternal antibodies? If there is no detectable antibody in baby's plasma you do not have to give antigen negative or crossmatched blood. What does your procedure/policy state?

JB

JOANBALONE,

Working in a small hospital, we don't get many requests for neonate transfusion here. Most of times, we transfuse a baby with uncrossed, O neg, IRR, CMV neg PC's and the baby usually get transferred to other hospital. However, in this case, the baby has been staying with us for a while. Our SOP states that XM for neonate should be performed with the mom's plasma when the mom has an antibody. As a general bench tech, I am not empowered to modify our procedures.

Autumn

Autumn,

Is it not possible to test the baby's plasma for maternal antibodies? If there is no detectable antibody in baby's plasma you do not have to give antigen negative or crossmatched blood. What does your procedure/policy state?

JB

Joan,

You bring up a good piont here however, what you are actually saying is that your antibody detection method is not subject to error and so if no maternal antibodies are detected then "you do not have to give antigen negative blood." You should remember that the total volume of the neonate circulation is vastly lower then that of an adult and therefore any sensitization and/or reaction can have very serious consiquences, before/during/or after, the start of the neonates own immune system, approximately 120 days after birth; curiously the same time frame for circulating life of the very donated red cells. This is why I would think that it is better to error on the side of caution and issue maternal antigen compatible RBC's.

I will use the mother's plasma or the neonate's elution to do the XM. Because if there is antibodies in the neonate's circulation , it will prefer to combinate with the neonate's rbc then if there is more it will free in the neonate's plasma, if the antibodies is weak then the free will be neg. And some antigen on the neonate's rbc is not mature, not so strong as adult cells, after transfusion the combined antibodies will elution from the neonate cells then combined with the transfused cells then cause more severe hemolysis. Upset the original balance.My discription is a little complex, I wish I do it clear.:p:p

Edited April 9, 201114 yr by shily

no crossmatch is done at our facility. We would transfuse antigen negative, CMV- irradiated O neg blood

I wasn't clear whether the mom's original sample was tested for antibodies when it was fresh or only when it was 5 days old. The anti-E was clearly still there so it would only matter for additional antibodies. Kidd antibodies are some of the least stable in storage.

Also, if the baby were Jka neg the eluate would not be expected to contain anti-Jka (until after you gave Jka pos units and it attached to the transfused cells and you did a new eluate for the transfusion reaction ).

We avoid drawing our infants. If we had tested the mother's specimen "within 3 days of delivery", then we select units based on mom's antibodies at that time (type O, leukoreduced, irradiated, fresh, antigen negative) and they are given without crossmatch. All delivering moms get a type and screen/ID. If we did not have, or could not obtain, mom's specimen "drawn within 3 days of delivery", then we would use the stored (up to 7 days) cord blood to perform type and screen/ID, select appropriate units, and give uncrossmatched. The vast majority of infants are born here and have a cord blood specimen in the fridge on hold. Only if there were no "near delivery specimen" (or results) from mom, and no stored cord blood (or results), would we proceed to draw the infant.

I hate to be ignorant, but I was always under the impression that cord blood plasma could produce unreliable results in antibody screening. Stickiness from Wharon's Jelly and all that...

Yes, we learned about that in school; however, I have never actually experienced the wharton's jelly problem. I guess this is because the cord blood is no longer "milked" or "stripped" to get the blood out. It is collected by venipuncture into the vein in the cord. This must produce a much cleaner specimen?

I mean, weren't you also taught to always wash the cord cells several times before ABO testing? And do you? We no longer do this, and yet we do not experience any trouble as a result. Future ABO tests are not discrepant.

Yes, we learned about that in school; however, I have never actually experienced the wharton's jelly problem. I guess this is because the cord blood is no longer "milked" or "stripped" to get the blood out. It is collected by venipuncture into the vein in the cord. This must produce a much cleaner specimen?

You are lucky that your cord blood specimens are 'correctly' collected. Ours mostly seem to be dripped or stripped (explaining the fact that the exterior of the sample tubes are usually grossly contaminated and disgusting with cord blood!). Within the last two months, we had two cord specimens with very strong interference from Wharton's jelly. We were unale to perform an accurate blood type. A capillary specimen from baby was required to obtain an accurate blood type. With a specimen like that, I would doubt that an antibody screen (or any other test) would be reliable.