jill

We dissolve 7.7g of DTT into 250 mL phosphate buffered saline made from a cube of saline that had a bottle of pHix(from Immucor) added to it.

Are you referring to 0.2M DTT or 0.01M DTT? There may be a procedure for making them up in the Methods section of the AABB Technical Manual.

Are your panels tested in tube or solid phase? If in tube, there's a possibility that this antibody may have formed against a constituent in your reagent cells based on the fact that all other allos are ruled out and you are seeing are seeing strong reactions with no pattern. I have seen these antibodies titer high. Try testing panels with washed reagent cells to see if it gets rid of the reactivity.

Did you try the prewarm testing technique to see if the Anti-M reacts at AHG? Did you try the prewarm testing technique to see if the Anti-M reacts at AHG?

The article I just cited was the same article as above by Sererat, Veidt and Dutched. (sorry)

We have a 1 hr TAT on STAT T&S. We usually meet that time frame because the ECHO takes 22 minutes to complete the test. We have to edit the sample in the computer and manually enter in results. This adds on another 5 minutes to the testing time.

There is an excellent article in Immunohematology, Vol 16, #4,2000 that decribes the validation of this procedure by the ARC in Columbus, OH. It compard 26 samples using IgG blocking, glycine acid EDTA, and chloroquine diphosphate treated red blood cells in typing for s,S,Fya,Fyb,Jka, and Jkb. The procedure works well with samples that have a w+ to 2+ DAT. One sample tested Fyb+ with the blocking method and Fyb- with chloroquine and glycine acid EDTA treated cells. I remember reading in the insert that chloroquine diphosphate treatment of red cells can weaken the Fyb antigen.

To demonstrate mixed field in forward typing, mix together the contents of one segment from a grp A blood unit and one segment from a grp O blood unit.

We use oil and run a positive and negative control.

I found out about it in Oct 2010 from a former coworker/blood banker while having dinner.

We require a new sample for each new admission. In this case a sample would be drawn for a ABO/Rh type.

We wash a suspension of cord red blood cells maunually 3x. From these washed cells we do an ABO and Rh type in tube. Also, from the washed cell suspension, 1 and 2 drops of it are placed into 2 respective tubes, wash 3-4 times in the cells washer and then add 2 drops of Anti-IgG to eaxh tube for the DAT.

The gel testing could be picking up a cold autoantibody. Do a cold antibody screen in tube. Do a DAT.

We do a type on screen on neonates for possible transfusion. We transfuse type specific blood so we also carry the Baby's plasma to the AHG phase when mom is grp O and baby is grp A, B, or A,B to check for presence of isohemagglutinin. If present we give grp O. The type and screen sample is good for the lenght of stay the infant is in house which can go up to 4 months as an expiration. A DAT must me performed if a previous cord sample was never done. If the screen is positive due to an alloantibody we try and identify it in the neonate's sample. If QNS, we use mom's plasma for ID and x-match.

OES I believe stands for Orhto Enhancenent Solution which is a low ionic strength solution. Often times warm autoantibodies are seen to be reactive using gel, peg, and'or solid phase but do not react in a low ionic strength medium. By testing patient plasma with it one can use it to rule out any coexisting allosntibodies. Another way to test patient plasma is by using 2 drops of palsma with one drop od reagent red blood cell. Incubate 30-60' at 37C, wash 4X, add Anti-IgG. warm autoantibodies often do not react using this technique.

I agree with you. Maybe we will in time especially since we do see alot of patients with warm autoantibodies.

We also have a signature line on our emergency release uncrossmatched tags. The Dr. signs at a bottom portion of the tag which has a perforated line locatd above so that this bottom portion tears off and is returned to the blood bank.

We do not set up phenotypically matched units for patients with a warm autoantibody. We transfuse Rh and K matched red cells to our sickle cell patients.

If the antibody is newly formed this can occur due to a "poor fit" that the new antibody has. As time goes on the antibody's FAB portion changes to fit its epitope better as the B cells become more mature in recognizing the red cell antigen.

When I worked with Alba's partial D kit we used saline cubes buffered with phosphate.

Thanks David.

The reference lab I worked in performed all initial work ups using LISS. If negative, and a cold was suspected then a ficin panel was tested. Also if LISS panel was negative a PEG screen was tested. For a short while prior to this, only PEG was used and a 4:1 screen at IS, RT and 4C were set up as the initial testing. A few of the submitting hospitals were requesting that our reference lab should acquire the gel methodology so we could duplicate their results. Gel/ProVue were subsequently acquired in the ref lab. Our experience also in this reference lab was that the requesting facility would detect nnspecific reactions in gel and solid phase and we would get negative results using LISS, PEG, and ficin treated reagent red cells. My experience now with solid phase has been seeing what looks like an antibody detected reacting 3-4+ with all 14 wells with negative and then negative reactions using gel and tube. When rouleaux has been rule out, I suspect that there is an antibody in the patient sample that is reacting against some unknown entitiy(stroma or chemical) that is affixed to the bottom of the u-shaped well. Also with solid phase, newly forming antibodies whose make up is largely composed of the IgM isotype (primary immune response) are on a few occasions missed using solid phase and then shown to demonstrate a clear pattern of reactivity in tube/LISS in which there is that valuable 37C reading. Also, the newly forming antibodies to not have the proper affinity in the hypervariable reagions of the FAB portion of the immunoglobulin which does not result in its proper fit with its epitope. This latter characteristic would result in a hard to or too weak to identify pattern using any methodology. Bottom line is to use all methodolgy that is available for ID purposes. If time and cost start to be an issue then flow charting based on what type of reactions seen with what methodolgy is of primary importance.

We recently had an OB patient with no history of antibodies have a positive 2 cell screen in solid phase. All 14 wells in panel were negative. The gel panel showed 3+ and 3- cells identifying an Anti-S. In tube/LISS this Anti-S reacted positive with the S+ reagent cells and at AHG all these reactions were negative.

The reference lab I worked in performed all initial work ups using LISS. If negative, and a cold was suspected then a ficin panel was tested. Also if LISS panel was negative a PEG screen was tested. For a short while prior to this, only PEG was used and a 4:1 screen at IS, RT and 4C were set up as the initial testing. A few of the submitting hospitals were requesting that our reference lab should acquire the gel methodology so we could duplicate their results. Gel/ProVue were subsequently acquired in the ref lab. Our experience also in this reference lab was that the requesting facility would detect nnspecific reactions in gel and solid phase and we would get negative results using LISS, PEG, and ficin treated reagent red cells. My experience now with solid phase has been seeing what looks like an antibody detected reacting 3-4+ with all 14 wells with negative and then negative reactions using gel and tube. When rouleaux has been rule out, I suspect that there is an antibody in the patient sample that is reacting against some unknown entitiy(stroma or chemical) that is affixed to the bottom of the u-shaped well. Also with solid phase, newly forming antibodies whose make up is largely composed of the IgM isotype (primary immune response) are on a few occasions missed using solid phase and then shown to demonstrate a clear pattern of reactivity in tube/LISS in which there is that valuable 37C reading. Also, the newly forming antibodies to not have the proper affinity in the hypervariable reagions of the FAB portion of the immunoglobulin which does not result in its proper fit with its epitope. This latter characteristic would result in a hard to or too weak to identify pattern using any methodology. Bottom line is to use all methodolgy that is available for ID purposes. If time and cost start to be an issue then flow charting based on what type of reactions seen with what methodolgy is of primary importance.

Hi Shelly, We do the same, however, we recently changed the last step in that we no longer need a physicians signature. Instead of the signature, we enter a charted comment in the patients profile that allows the blood banker to call this warm autoaby as a critical result to the RN. Any units that are least incompatible due to a warm auto or HTLA are considered critical results.