Pat Distler

I think we need to pose that question to the FDA, since I'm only interpreting this regulation. I will see what I can find out about their current thinking, but this may take a few days.

Dedicated units are when a donor is allowed to donate more frequently than the usual 8 weeks for whole blood because of the special value of the units to the patient. This is most common when a parent is donating small amounts of blood on a weekly basis for a sick infant. Dad comes in once a week and gives 100 mL, for example. As long as his hematocrit is acceptable (or with medical exception), he donates weekly. His blood is used exclusively for one patient, his child. The blood might well be eligible for crossover, but you wouldn't want to cross it over routinely. If you did, it might appear as if you were violating the 8-week rule without good cause. On the issue of 21 CFR 606.121 (. I understand that during the transition from Codabar to ISBT 128, FDA will allow some over-labeling of non-product code information. This is so that facilities can deal with blood suppliers being out of synch on converting (some converting earlier than others). However, this flexibility shouldn't extend to overlabeling an ISBT 128 label with another ISBT 128 label, as was described in the scenario above.

First, we need to differentiate between a designated unit and a directed unit. A designated unit is one from a donor selected by the collection facility because it has some special value to the recepient--e.g., it's an HLA-matched platelet, or perhaps a cellular therapy product that is carefully matched to the intended recipient. Directed is when the patient has selected his donor (family member, friend, etc.) and asked them to donate a unit of blood. These definitions can be found in the US Consensus Standard, page viii (beginning of the document). So, 4 in the product code is for a designated donation. Is this how it is being used? This product could logically be crossed over. If it's an HLA-matched platelet, and the intended recipient didn't use it, you would certainly would not want to waste it. (For cellular therapy, even if it could be crossed over, it's unlikely that another patient could use it.) Relabeling (affixing a new product code) or not is up to you. It is not required--the 4 merely shows a history of having been drawn as a designated unit. However, if you choose to relabel it, a "V" would be appropriate. A "D" (directed) is not appropriate for a unit that was collected as a designated. Had it been labeled with a "D" for directed, you also have the choice of whether or not to re-label. Again, "V" would be appropirate. Leaving the "D" label merely shows the unit was originally collected as a directed donation. We are not using "directed, for crossover" codes in the ABO/Rh in the US. This is because it would make the ABO/Rh look very different--and you'd almost have to re-label the ABO/Rh if you wanted to cross it over. Not only is there a risk to overlabeling the ABO/Rh, I interpret 21 CFR 606.121 ( to indicate you shouldn't be obscuring the ABO/Rh of the collection facility. So, to avoid the need to over-label the ABO/Rh, the US chose not to encode "directed, eligible for crossover" into the ABO/Rh. (It can be encoded in the product code, as is discussed in this thread). Other directed types are infrequently used in the US (directed, not eligible for cross-over or directed, biohazard). Because these units cannot be crossed over, it's okay that the ABO/Rh label shows it's intended for one, and only one, patient. I'm not familiar with this aspect of the Digi-Trax software, and defer this question to Richard Kriozere. Richard?

The first time you make an alilquot, you can designate the parent unit as A0, and the first aliquot as B0. Thereafter, the parent unit remains A0 and subsequent aliquots are named Aa, Ab, Ac, etc. There is no requirement that the aliquots be removed at the same time, or that the be of equal size.

Using the ISBT 128 red cell antigen (special testing) bar code is entirely optional. You may continue to label the red cell antigen phenotype as you have in the past. The advantage of bar coding the informtion would be to verify that the unit has been labeled correctly, if your computer system is able to interpret this bar code.

Although I was asking about ISBT 128 labels at the time, an FDA staffer told me this information was not necessary.