JHH1999

Typically expiration dates are established by the manufacturer. They perform stability testing for the duration of the assigned expiration date to support it with data. Data shows the product is capable of performing up until the claimed expiration date. It may continue to function they just do not have data to support it. This should be done to support any "reagent" made that is not at least qualified in some way each day of use. Assigning an expiration date based upon the shortest dated component is not very good science. The different ingredients could be compatible with each other or could have a negative impact to on another. From a pure scientific and quality aspect one would prepare a reagent and place it on a stability schedule and test it periodically for performance. This data is then used to support the use. Any assessor should accept this science. A simple analogy I like. If you made a cake today with milk that had a use by date of tomorrow does that mean the cake is not good after a day. Of course not, since it is now in a different form and could be stored in a different way.

Basically some labs struggle with QC and the actual intent. They also may have issues with staff not detecting weak reactions, specifically in tubes. Manufacturer's in the US tend to make QC material so strong that it is less likely to be missed. The result is the manufacturer avoids product complaints and the labs do not have QC failures requiring investigation. However, the intent of QC is missed in my opinion. QC should ensure your test system is capable of detecting weak reactions. QC products manufactured where I work were developed (IgG coated control cells and Daily QC Kit) to detect if there is a weakness rather than just checking a box that QC has been done.

As a reagent manufacturer one of the requirements is to ensure products work as intended over the shelf life of the product when in the end users hands. This includes ensuring the product is able to withstand shipping. Manufacturers perform stability testing of these products to a greater extent than most end users would be cabable of repeating. This would include making sure red cells antigens are viable. Daily QC of red cell panels by the end user is not necessary in my opinion and a waste of time and resources.

Using expired antisera and panel cells is and has been standard practice for years in my experience. It has become more sound with additional QC people are now doing. If ever cited for this I would push back. Provide scientific rationale and a risk evaluation for what you are doing. These are tools used to solve problems. Without them your hands are tied and patients may not receive compatible blood. A bigger risk. No matter what you call them (inspectors, investigators, assessors) they all have opinions and you may not be about to change their mind during the inspection. What they may cite you for during an inspection can be disputed in your response. The repsonse is typically reviewed by others. Some of these things are just driving up the cost of health care without improving actual patient care.

I agree with Malcolm. DNA work can predict, but does not show if the antigen is expressed. To complicate things, does it matter regarding transfusion therapy. Do we provide "gene" compatible blood? This could decrease your donor pool. Additionally, it will be interesting to see how insurance companies will see paying for something more expensive when less expensive serological phenotyping is available and still meets patient needs. DNA work is interesting and can be a good tool for investigating the strange and unusual, but it may complicate things too much for routine testing and currently not licensed by FDA.

Check the package insert for the monoclonal Anti-IgG. It may give you an indication if that particular reagent does not detect IgG4 antibodies. We have seen this before for some alloantibodies such as Anti-Yta which can be IgG4.

I am not familiar with UK regulations, but in the USA blood grouping reagent specifications are listed under 21 CFR 660 Subpart C. The other document available is older, but it is currently the only guidance I'm aware of that indicates which low incidence antibodies are required to be ruled out. Bg antibodies are not required, but we try our best to rule them out to prevent problems for customers. There has been the rare occassion where a polyclonal reagent does contain a low incidence contaminant that is not required to be ruled out. The availability of rare cells can be a problem and where does it end with all the lows known to exist. No enzyme testing is required. http://www.fda.gov/downloads/BiologicsBloodVaccines/GuidanceComplianceRegulatoryInformation/Guidances/Blood/UCM080926.pdf

I have been performing serological tube testing my entire career (over 20 years) and I don't recall seeing anyone covering tubes when centrifuging for typing, screens or panels. We still use old reliable Clay-Adams Sero-fuges as well as cellwasher 2s. Someone I guess could be concerned about creating aerosols, but I think the risk is extremely low. It may be just referring to spinning down samples at initial receipt (larger volumes). If you were to take this statment seriously and cover all tubes when centrifuging, I would say good luck when the covered tubes are placed in an automated cell washer like a cellwasher 2.

At this point I do not believe molecular testing is licensed. Molecular testing can be used for screening and investigating strange serological reactions. Since it is not licensed I do not think you can label the units. You would need to confirm the antigen typing with a licensed test method.

If you are not detecting the Anti-E on the Tango and also now not detecting it in gel or tube with PeG, it does not sound like a problem with different methods.

Glad I could help. Now being in the reagent manufacturing world we get to see some strange things like this come up when trying to resolve customer problems with reagents. This just happened to be one we saw recently. Reminds me of old reference lab days.

This sounds like a little known phenotype that has been previously identified. The patient is most likely S-s+U-Dantu+. We found a donor with this phenotype not long ago. It was also described in Marion Reid's The Blood Group Antigen Facts Book.

We have found DTT to be very stable when frozen. As long as you run a proper control to ensure the DTT is working each day of use, it should be fine for many years. It may be wise to establish some stability data (what manufacturers of reagents do) that can be used to support its use over time if you are making it up yourself. This can be done by preparing DTT and storing it frozen in aliquots. Then periodically test it to ensure it denatures a Kell system antigen for example. This data can then be used to support an assigned expiration date.

I am not aware of any regulatory requirement for blood banks to validate the use of a FDA licensed reagent. The FDA does not validate reagents. They review and approve the work done by the manufacturer to ensure their claims are accurate. If you follow the manufacturer's instructions and run the necessary controls daily, you should be able to put them into use without any further testing. Any additional work would be in my opinion a waste of time and valuable reagent. As far as the gel thing, I have heard something about the patent on that technology ending allowing others to start making gel system supplies to compete with Ortho.

Just an FYI. All licensed blood grouping reagents must meet FDA requirements for potency, reactivity and specificity. In order to license these reagents they must undergo significant clinical trial testing to ensure they are giving accurate results. It is one thing to compare or evaluate how these reagents perform against each other in your hands, but the manufacturers have performed far more testing than most end users would even think of doing. I would caution against going overboard on "validating" the use of these reagents. As previously mentioned, pay close attention to the directions for use. Some newer monoclonals have different incubation/spin time requirements and even different saline requirements. If these are not followed, your reactions may not be what you would expect.