Mabel Adams

I would turn these out as "too weak to titrate" if tube testing of neat sample was < 1+ in tube/saline/IgG. One could also say "Titer < 1" which is what I did if I had gone ahead and done the titer and it came out neg (or <1+) in the first tube.

I have just changed jobs and moved to Oregon. They are ramping back up to a level III NICU here and we are to meet with the new neonatologist. I have some questions for you with NICU experience. Do you worry about giving Rh neg plts to female neonates that are Rh neg or do you consider their immune systems too immature to make anti-D that could affect them in their child-bearing years? What do you do for emergency transfusion of plts to neonates when your usual stock of AB plts in unavailable at the moment you need to transfuse plts to a baby with unknown or non-O type? We do not have the ability to volume reduce. Obviously we would use type compatible if available, but what if the only products available are plasma incompatible? Do you leave it up to the doc whether to wait for some to come in (6 hours) or give plasma incompatible? Can you direct me to a good source of filters and syringes to use to aliquot red cell and plt units in the BB? How would you validate these? What is different about saline that is labeled "safe for neonatal use" compared to Normal Saline? How long do you use an irradiated unit for a baby after it was irradiated (my reference says due to K+ increase, they should be given ASAP)? Recommendations for sterile docking devices also appreciated. Thanks

I think Galvania covered this pretty well. Too bad our terminology and reagents don't really correlate with the biology. Weak D is a misnomer for a partial D that types 4+. We have changed Du, weak D etc. terminology at least 3 times in the past 30 years; maybe we should make another try that fits the situations better--or should we wait for molecular testing to clarify things?

Although we allow 2 single-dose K cells, we must not fall into the belief that this is actaully more sensitive than one single-dose cell. Due to dosage, a double-dose cell may be more sentitive. But using 2 single-dose cells reduces the likelihood that an anti-K will be missed because one of the K+ cells did not react due to technical or other difficulties. Statistically, anti-K is a very common antibody so it is worth some extra effort to make sure it is not there.

I will tell a story if it could help someone else. We used to wash our cell suspensions for fetalscreens (and for everything else for that matter). I would decant the washings by holding more than one patient's tubes in my hand--usually some prenatals I was doing along with the fetalscreen. On several occasions I got similar results to what you are finding. I figured out that the other tube in my hand was always an Rh pos patient. When I flicked my wrist at the end of the decant, I must have splashed a miniscule amount of Rh pos cells into the fetascreen cell suspension. This was never enough to show up in any other kind of testing I did on it, but it did cause some rosettes to form. When I would repeat the fetalscreen on a new cell suspension, it would be neg. This might not be your problem. What do you find when you repeat the same and new cell suspensions on your fetalscreens? I have another theory since many of us use EDTA for ab screens now. Fact: reticulocytes will end up on the top layer if you spin a sample down in a capillary tube. Fetal blood is more likely to have retics (and bigger cells that are somewhat like retics), so if we don't do fetalscreens and Kleihauers on well-mixed samples, could we pull the fetal cells off first? We draw our fetalscreens in purple tops instead of the pink tops we use for gel testing just so we don't spin them down out of habit, then sample only from the top layer of cells when we make the suspension.

I have been trying to order anti-C monoclonal from Immucor and find that it is backordered indefinitely. I am guessing that it is backordered till the price increase is in effect, but maybe not. Does anyone know what is going on? Gammaclone control and anti-IgG green are also backordered. I can get by without these for awhile but I am about out of anti-C Anyone know of a source of monoclonal anti-C that uses the same testing steps as Gammaclone (IS & 15 min RT)?

The denominator is total cells in our calculation.

Good point. I must admit I am going from memory and didn't think that part through particularly. They might have estimated the residual from flow cytometry (D antigen) or even repeat fetal screens or just D typing.

We do it every time based on the KISS principle. Then new techs and generalists don't have one more set of exceptions to remember. It is quick, easy and cheap. Complement him on his higher understanding of serologic principles then tell him to do it anyway just to keep things simple and consistent. Put that brain to use thinking about something that can make better use of his intelligence! I bet he would be good at making suggestions of ways to improve processes--changes that could be written into SOPs that everyone would follow consistently. Changes that would make more difference to the end product than tilting at this windmill. Sorry, got going a bit, didn't I?

What if a patient presents a donor card with his blood type on it? Would we accept that? If so, how would we document it. In fact, documenting any outside type in your computer system might be what determines what you will accept. Computers often run out lives!

The clinical situation would have impact but even with something chronic like myelodysplastic syndrome, you'd think the doc would want to see if they are even lower. Most other situations might have mitigated themselves over 4 weeks making transfusion unnecessary or even dangerous. In a chronic outpatient I don't see how you should go back more than about a week--less if more acute causes are implicated.

We went to diluting our own screening cells (Immucor's) to 0.8% and our false positive rate in gel is now quite manageable.

I wonder if the second tech forgot to put serum in the IS xm tube. The volume would have been low, but if she were distracted enough she might not have noticed it.

We have two main concerns: Bacterial growth if unit contaminated and factor degradation. Plt in closed system can be stored for 5 days at room temp, but we know they have a higher frequency of transmitting bacteria to the recipient (unless the newer approaches have improved this). Plts are so precious that may be an acceptable risk not willingly taken on for FFP. There is now a good bit of research about factor changes over time, but I am not sure it includes much with room temp. storage. This would be a good SBB project, no?

We don't repeat types for add-on orders, but our policy requires checking that the band number and patient ID match for specimen currently used and specimen on record. Also our computer keeps all add-ons on the same specimen number for the life of the specimen (3 days) so it is easy to make sure we are using the same specimen. We do a DAT or Auto control only with Ab IDs, not screens. We are an independent lab serving 2 hospitals that total about 150 beds.

I assume the c3d check cells are run in gel in a separate well from the patient test. In tube testing we run check cells to make sure washing was adequate; since there is no washing in gel, it seems to me we should only have to run the check cells once each day of use, to prove the anti-c3d reagent is active.

We use Immucor's EGA kit for removing antibody from cells we need to be able to type afterward, like for weak D testing on a baby with a positive DAT.

Dade cellwashers, even though they have a resuspend cycle, don't completely resuspend the cell button between washes. This is why they aren't as good for PEG testing. This might be where the recommendation to check this came from.

As far as I know Meditech chose to maintain the A & B etc. suffixes when it makes aliquots or when it imports them. It gets really messy if you need to modify them (make components) like thawing FFP or irradiating aliquots. They are supposed to be realeasing a DTS that helps with this problem. I will try to remember to post the number when I get to work tomorrow.

Some of us don't make "thawed plasma" and need those codes for our 24 hr. exp. products.

We serve as the lab and transfusion service for a small hospital 15 min. away. The "lab" at that hospital is a phlebotomy area with the blood fridge in it. We have a log book that units placed into the fridge are logged into by lab couriers or phlebotomists so we can track every step of the unit's life. The nurses add to this log when they take a unit out (or return and reissue). Two nurses check all ID etc. at the bedside. This hospital recently had a state surveyor say that they need to have two people there in the lab to issue the blood from the fridge. They could bring two nurses down to sign out blood, but that is a staffing issue. We could train phlebotomists to sign out blood but I am not comfortable due to the training process, "culture" and high turnover. We think of their fridge as a remote fridge (not part of the transfusion service) so in our minds "issue" (with all its regualatory requirements) happens when we send the blood over there. We issue from the computer system here which is not available to them over there. All documentation there is on paper. What do others with remote refrigerators do to 1) meet regulatory requirements and 2) assure that the right blood is being taken to transfuse?

Our supplier is still trying to decide if pre-pooled cryo should have a 4 or 6 hour exp. once thawed. They hope to have an FDA license by fall.

We only do screens not types in gel so far. We use a known neg patient sample for the screen neg control. Can your blood supplier give you some AB plasma? Can you use the "plasma" from the segments on an AB unit? (that might be dicey since there really isn't that much plasma there--mostly Adsol). What might cause a false positive in a gel reverse type? There's the card, the diluent, the cells and the plasma. Would any of the first 3 cause a false positive reaction with plasma but not with albumin, diluent or any of the other suggested controls? If there would be no difference then those should work as controls.

Thawing for in-house use does not require it, but pooling/aliquoting does is my understanding.

It seems splitting the grades is most useful when we want to compare reactions--looking for dosage or a different specificity on a panel, for instance. It doesn't seem like there is much to compare with routine grouping/typing. Maybe in bone marrow transplants where you are watching a patient's type change over time as the graft takes hold it could be useful??? Even then I would think full grades would be sufficient.