Folks, have noticed over the years blood bankers getting out of performing adsorptions on warm autos etc. by resorting to saline incubation at 30 minutes (no enhancement) and then "calling it good". I really have a problem from a technical standpoint supporting what I consider a bogus SOP. Can one actually detect alloantibodies via this method? I've never seen where it could. I mean really now. NO enhancement, then washing the cells, followed by AHG. I understand the convenience but what's the science to prove its reliability?

I see where the AABB technical manual still lists this "SOP" in their manual so of course this gives people tacit permission to use it. Opinions please.

Well labgirl153, there was a little paper written in 1945 by Coombs et al (Coombs RRA, Mourant AE, Race RR. Detection of weak and “incomplete” Rh agglutinins. Lancet 1945; ii: 15-16) that rather contradicts your theory of this SOP being "bogus". I think that you should remember that, before we had enhancement, this was the ONLY indirect antiglobulin technique that was available and that, although a few patients may have been "lost" due to incubation period, none were "lost" due to antibodies not being detected, as long as the test was performed correctly.

If you do not acknowledge,remember and learn from history, you are doomed to live through it again.

I agree with Malclom (as usual)

Malcolm, now you don't really expect me to adhere to a single paper from immunohematology's ancient priesthood to hold water do you? Hope you were being sarcastic. Where's any recent evidence (in this century) to support that this "technique" is actually capable of detecting significant antibodies? I want facts - not a 67 year-old paper. Have been a blood banker for many years, but have not seen any studies of comparison with this technique with any other to validate its existence. Are there papers on this since that time? Believe we're doomed if we don't revisit a technique that's older than most of us here. Immunology has come a long way since 1945.

My question was valid and deserves a better response. Can tell from the responses that this "technique" is indeed suspicious.

labgirl153,

If you don't mind, you seem the type that needs evidence for yourself, so I would recommend a little experiment at your convenience; make a serial delution of your Anti D reagent using Saline and cross this with standard Rh pos 3-5% reagent cells for varying lengths of time; ie Series 1:2 to 1:32 (to start) and run several sets of these reactions, one set at 15min 37C inc., another at 30min 37C inc, and 45min 37C inc, and lastly 1hr 37C inc. Wash and coombs and check for agglutination. Let us know what you get.

Edited August 5, 201213 yr by rravkin@aol.com

Well, that's mighty nice of you to suggest busy work for me RRavkin. My question relates to literature in the past half century. Surely, in the 67 years since its introduction, someone has made a comparison of the saline incubation technique to other methods. If not, then that speaks favorably toward tradition but is not so flattering toward the upper echelon in blood banking. Believe I'll take this SOP question up with the AABB folks and possibly CBBS. Hopefully I'll get a response directly pertaining to "papers" and "research". If not, then the answer will finally be clear.

Time out

Labgirl, are you referring to a 37C tube IAT, with red cells suspended in saline, with a 30 minute incubation, that gives a 'negative' result?

With all due respect labgirl, you asked for opinions. It appears you only want to hear opinions that are in line with your way of thinking. Differing opinions are healthy. Sometimes we come to see things differently and sometimes we have to agree to disagree. It is a shame this thread will probably end now that you have decided to take the discussion elswhere. :disbelief

Labgirl, I have not written any papers, but we do use the ancient technique in our lab occasionally. It was recommended to us by our reference lab. We use it when we are getting what appears to be a warm auto antibody in ortho gel. We have "uncovered" a couple of anti-E and an anti-K by using the saline "enhancement"/anti-IgG technique. I works for us, and we have not used autoabsorption in quite some time. Try it.....you might like it.....

Labgirl, I have not written any papers, but we do use the ancient technique in our lab occasionally. It was recommended to us by our reference lab. We use it when we are getting what appears to be a warm auto antibody in ortho gel. We have "uncovered" a couple of anti-E and an anti-K by using the saline "enhancement"/anti-IgG technique. I works for us, and we have not used autoabsorption in quite some time. Try it.....you might like it.....

Hi Swede...you're the first tech I've read of that's found positive reactions using it to uncover significant allos. Thanks for your input.

And to BMarotto...no, I don't have my own agenda at all...am looking for the science behind it, not a history lesson.

Well, that's mighty nice of you to suggest busy work for me RRavkin. My question relates to literature in the past half century. Surely, in the 67 years since its introduction, someone has made a comparison of the saline incubation technique to other methods. If not, then that speaks favorably toward tradition but is not so flattering toward the upper echelon in blood banking. Believe I'll take this SOP question up with the AABB folks and possibly CBBS. Hopefully I'll get a response directly pertaining to "papers" and "research". If not, then the answer will finally be clear.

Please let us know what you find.

Well, that's mighty nice of you to suggest busy work for me RRavkin. My question relates to literature in the past half century. Surely, in the 67 years since its introduction, someone has made a comparison of the saline incubation technique to other methods. If not, then that speaks favorably toward tradition but is not so flattering toward the upper echelon in blood banking. Believe I'll take this SOP question up with the AABB folks and possibly CBBS. Hopefully I'll get a response directly pertaining to "papers" and "research". If not, then the answer will finally be clear.

I worked in two UK Blood Transfusion reference centres (Bristol and Cambridge) prior to Ross & Ducie publishing anything on enhancement solutions like LISS for IAT. The standard technique for both antibody identification and then cross-match was one hour at 37oC for IAT. If they needed blood quicker and couldn't wait then use O neg...

Hi labgirl153,

I won't weigh in with an opinion or facts regarding your question, I will ask that you reconsider your harsh tone toward some very smart people who are offering advice and their many years of experience. People here are not paid for the time they spend helping others, and responses such as your will lessen their willingness to continue. Remember, You can catch more flies with honey than with vinegar.

We are a CAP accredited lab and 2x year we compare all our testing methods. We compare gel, LISS, PEG, saline techniques. All methods have detected all clinically significant antibodies.

R1R2

We are a CAP accredited lab and 2x year we compare all our testing methods. We compare gel, LISS, PEG, saline techniques. All methods have detected all clinically significant antibodies.

R1R2

I should, perhaps, also mention that the Red Cell Reference Laboratory of the WHO INTERNATIONAL Blood Group Reference Laboraotory (the IBGRL) t NHSBT-Filton Centre, Bristol, England, uses tube IAT almost exclusively, and they aren't bad at serology!!!!!!!!

I think I'll pass on joining this discussion since I am old, retired and can't possibly contribute, but thanks for asking.

Labgirl, I'm gently disagreeing with you as well. Not everyone does autoadsorptions, and far fewer can do homologous adsorptions on the recently transfused or have the luxury of the time and $$ to send it out to a reference lab to perform. While, in some cases, it may be less sensitive than some techniques, saline testing will still do a good job of detecting most antibodies. There was no plague of acute hemolytic reactions during the decades when saline or albumin testing was the norm. No technique is the best in all cases, and the sensitivity of gel and solid phase can be a double-edged sword when autoantibodies and other insigificant findings pop up in the testing. What about the "garbage" reactions seen with these technologies, where techs report "Gel- (or solid phase-) reactive antibody of undetermined specificity" and give crossmatch-compatible, or repeat the screen with PEG and just report it as negative? There are many other scenarios where there may be a slight trade-off in sensitivity, such as the dilutional factor involved with using inhibitory substances (Lewis, P1, Sda, Ch/Rg, REST etc), but it's acceptable in terms of the outcome ("calling it good"). There are acceptable risks associated with any transfusion, such as those with immediate spin or computer crossmatches, where antibodies to low-incidence antigens not on the screening cells may be missed. The potential risk of "missing" an antibody that's teetering on the edge of detectability is outweighed by the advantage of getting rid of the interfering activity and getting your patient some blood.

We will sometimes use no enhancement media to avoid warm autos (and colds), using 3-4 drops serum, a 60 minute incubation, and mixing the tubes a few times during the incubation to let more cells bump into more IgG.

And it's not a bad idea to check it out yourself if you have doubts about any procedure. Our LISS reagent cautions about maintaining the proper 2/2/1 ratio of LISS/serum/cells, which made me nervous about some techs not carefully counting their drops. So I titered antibodies in non-reactive serum and tried the dilutions with 2/2/1, 4/4/1, 4/2/1 and 2/4/1 ratios and found no appreciable differences. I'm not advocating going against P&P but I felt better knowing the world wouldn't end if someone added an extra drop. You might feel better yourself about the saline technique.

Quote: "We will sometimes use no enhancement media to avoid warm autos (and colds), using 3-4 drops serum, a 60 minute incubation,..."

We also use this technique as the only way we can attempt to see under Solid Phase/PEG warm autoimmunes here. We have used the procedure for years and can routinely see the known alloantibodies, if still present. Since our Reference Lab (I will put in a plug here for the finest reference lab I have worked with - Gulf Coast Regional in Houston, TX - fast, accurate and nice to work with) is a plane flight away, sometimes we have to do the best we can with what we can do on site. Allo and Auto Absorbtions haven't been doable here for some time, so we use the one hour, saline enhancement procedure for "looking under" warm autos. We will back down in sensitivity through Peg and LISS first, but if the warm is still interfering, we will go to 1 hr, saline enhancement as our last resort. We have had allo and autos (still!) show with this routine. The method has been validated with several known antibodies and was originally recommended in a AABB seminar from another reference lab, but I don't remember who or when.

I appreciate so much, all of the help and advice and shared knowledge found on this site, especially from some of the senior posters such as Malcolm. I too objected to your tone and responses. Try validating the SOP yourself, you will find it does work and you may find you appreciate the method.

labgirl153, step back a minute and re-read this sentence: now you don't really expect me to adhere to a single paper from immunohematology's ancient priesthood to hold water do you?

You have asked the folks on this board to comment. If you choose not to "agree" with someone that's fine but you are coming across a little snipp-ey for lack of a better description. rravikin is not suggesting more work for you, I read his suggestion as just that, a suggestion.

We have lots of tools on our antibody ID toolbelt and saline enhancement is just one of them. Think about it, there is no enhancement medium "in vivo" so what's wrong with using this technique? If your not comfortable with it don't use it. Just because it's in the AABB technical manual doesn't mean you have to use it either.

Do what you feel is best for the patients you care for and relax. This is a fun place to exchange information, not snipe at your fellow Blood Bankers.

Well, well! Looks like I rattled a few of you. :cool:. Just didn't want someone to get away with patronizing me after that first response regarding "history" (and yes, it was patronizing). I do appreciate many of the insightful and thoughtful responses that eventually were offered. I will re-read and take each into consideration as well (honestly).

Have worked with some very tough crews and frankly, blood bankers often "eat their young" so if I came off as snippy, then I apologize - my background and experience surviving the "superior" crowd has shown through. Have asked many a question here and given a few in reply over the years w/o being "snippy" so this is a first. I do grow tired of the "priesthood" and the stuffiness encountered over the years.

Well I ,for one, thought it was a good line! I had assumed that your "tone" was a bit of a tease and (at least a bit) tounge-in-cheek!

Scott

I just want to mention the saline titration procedures that are in the Technical Manual and that the CAP promotes as their preferred procedure. Their supporting paper will pretty clearly show that saline technique can detect antibodies (see the CAP website). I have seen many antibodies react when titrated by a saline technique.

Mabel I've used the saline titration as well...some of the antibodies successfully titrate to a decent degree but I've seen where others are "wimpy" and unsatisfactory. Depends on the antibody and Ig class.

A wise man you definitely are Scott

Dr. Pepper asked:

Think about it, there is no enhancement medium "in vivo" so what's wrong with using this technique?

Edited August 8, 201213 yr by labgirl153
grammar