Some insight please

[3cardmoe]

Could someone please explain this to me:

              

             -Panagglutination in a gel panel (W+ to 1+) with a negative autocontrol

             -A tube screen with PeG was performed. Immediate spin was negative and 2 of the 3 screening cells were weakly positive at Coombs. Again, a negative autocontrol at IS and Coombs

 

 

The sample was sent off to the reference lab and they called a Cold Autoantibody. If a Cold Autoantibody was suspected, would we not expect it to show at immediate spin? Especially since it followed through to Coombs? Or at least would we call something in addition to the Cold?

 

Any insight would help!

Edited November 15, 2013 by hillDi

[L106]

Quite frequently, a cold autoantibody may not react on immediate spin (or demonstrate a positive reaction in the auto control), until the testing is dropped to a colder temperature.

 

We often observe a "panagglutinin" (or often, reactions with some panel cells but not all panel cells, giving us a pattern that cannot be identified.)  When we test the patient's plasma with screening cells and an auto control and incubate the tubes in the refrigerator for 15-30 minutes, then we see all the cells and auto giving 3+ or 4+ reactions (indicating the presence of a cold autoantibody.)

 

Donna

[David Saikin]

I like to run an ABO compatible cord cell or 2 when I do a cold screen.  I will run 3 screening cells, an auto, and 2 cord cells at immed spin, after 5 minutes at room temp and then again after 5 min at 4C. I may also run an A1 and A2 cell if the pt is an A or AB and I suspect anti-IH - just for fun.  You have to read the 4C tubes very quickly after centifugation because you are not blasing them with cold as Donna does.  If you let them sit around the rxs will disappear rapidly as they warm up (if they were even there to begin with).

[Yanxia]

Could someone please explain this to me:

              

             -Panagglutination in a gel panel (W+ to 1+) with a negative autocontrol

             -A tube screen with PeG was performed. Immediate spin was negative and 2 of the 3 screening cells were weakly positive at Coombs. Again, a negative autocontrol at IS and Coombs

 

 

The sample was sent off to the reference lab and they called a Cold Autoantibody. If a Cold Autoantibody was suspected, would we not expect it to show at immediate spin? Especially since it followed through to Coombs? Or at least would we call something in addition to the Cold?

 

Any insight would help!

I don't think it is cold auto. I prefer to call it warm antibodies very weak to show specificity.

[Abdulhameed Al-Attas]

I agree with David Saikin.

[Auntie-D]

Why are we still bothering with tubes? In the UK tubes are only done in XM to confirm ABO compatibility, everything else is done in gel...

[Eagle Eye]

why do the reference lab always run panel/screen at 4C. We are in east coast and more than 60-70% of our patient comes back with cold autoantibody and some thing else.

I am asking same Q. why are we doing screen or panel at 4C.

[Malcolm Needs ☆]

Not all Reference Laboratories do this Eagle Eye!  We don't.

[Eagle Eye]

Well......talking about US east coast...

sorry....

Edited November 18, 2013 by Eagle Eye

[David Saikin]

Why are we still bothering with tubes? In the UK tubes are only done in XM to confirm ABO compatibility, everything else is done in gel...

I don't know about others but gel is the not the end-all, be-all in antibody studies.  For instance, if I am doing an warm auto - I have never been able to absorb all the warm ab out of the specimen if I test in gel.  I always go with a PeG autoabsorption and do my studies in tubes rather than gel.  I don't think I am going to miss any signficant allosensitization using tubes for this scenario.  I still have referrals that use tubes and 22% albumin or LISS routinely, I like to be able to reproduce their results using the modalities that they use (when necessary).  Sometmes gel is just way too sensitive and if I back off the sensitivity I can get a clear cut result. I feel the same way about the capture technology - sometimes it is way too sensitive.  Tube testing, I believe, is still the standard of care regardless of what the vendors are saying or even that the majority of users use the newer technologies.  I also do NOT run all specs in the cold - only if the studies indicate a likely cold reacting moiety.

Edited November 19, 2013 by David Saikin

[Malcolm Needs ☆]

I agree David.  We use tube techniques on almost a daily basis in my Reference Laboratory (although Bio-Rad gel column agglutination technology is our first line of defence).