Is anyone having 1+ reactions with 0.8% Surgiscreen cell number 2 that either show very few scant reactions or no reactions at all with panels A and B.?  We have opened new boxes of the same lot, VSS789, but still have the random 1+ positive on cell number 2.  We have had 6 patient samples, both Rh positive and Rh negative since we started this lot on 02/03/16. Very frustrating for my techs.

Several months ago may be 6 or more we had the same problem and with SCII.  We made a complaint to Ortho but they denied any problems with their product because there weren't enough complaints???.  we tried a second bottle from the same lot fearing the bottle was contaminated no difference.  The controls were always positive or negative as expected.  fortunately when this started happening we had a new lot of cells and all those we tested with SCII positive retested negative.  Of course this is after doing several panels .  I think the only patients that were effected were O+.

 

 

We discovered this issue last night and yes Ortho has had a number of complaints.  The recommendation is to use a different lot of 0.8% cells or to use 3% cells which have been diluted to 0.8%.

We have started making 0.8 cells from our 3% just this week, and all testing was negative. Thank you for the validation.

 

YES!   Glad to know we weren't the only ones!

I experienced this situation a few times (I think one is too many!) where the DAT is positive (gel IgG). This is why as soon as we receive a new lot, I perform lot to lot comparison. If there is an issue, I call right away Ortho and they ship me overnight stat a different lot # free of charge for us.

I know a few labs switched to 3-5% Biorad cells and make their own 0.8% daily suspension. I am thinking about it, but I do have other fish to fry for the moment!

Helen

Can I make some comments about this type of reaction 'from the other side'.  It is easy to forget that reagent red cells come from real donors who have complicated antigens on their red cells.  The donors will be tested for as many antigens as possible, and the presence or absence of those antigens will be noted on the accompanying antigen sheet.  However, it is impossible to test for all those low frequency antigens (LFA) out there.  And unfortunately, antibodies to LFA are often far more 'common' than you would expect.  So, if you're getting an unexplained positive reaction with a reagent red cell it's probably due to an antibody against a LFA.  And the manufacturer is not going to be able to identify it; all they can do is withdraw it from use for the future.  these results are not false positive but unidentified (and probably unidentifiable) positives.  Your reference lab might be able to identify it if they have a good sample from the patient together with a sample of the cell.

As for reagent red cells with positive DATs when used in gel (Frenchie) - you will sometimes see positive reactions in IgG or poly AHG in cards if you put the reagent red cells on to the cards without any plasma, due to the fact that the cells are not meant to be used in that way.  Usually if you repeat with neutral plasma, the 'positive DAT' disappears.  If it doesn't, either there is a real problem with the cell (unlikely) or it has become contaminated in your lab.  And - Frenchie again - I would advise you against diluting 3% cells for use in cards.  You could be creating more problems than you think you are solving.

Another reason that you might see unexplained positives is antibodies to Bg.  As far as I know all manufacturers test their cells with a panel of anti-Bg antisera.  However, we all know how variable Bg can be.  You can test a cell with 20 anti-Bg and maybe only 1 of them is positive; and vice versa someone with a known anti-Bg won't react with all Bg+ cells.  So if you are seeing a fairly high number of unexplained positives, especially in pregnant women, then you shuld suspect Bg.

 

4 hours ago, galvania said:

Can I make some comments about this type of reaction 'from the other side'.  It is easy to forget that reagent red cells come from real donors who have complicated antigens on their red cells.  The donors will be tested for as many antigens as possible, and the presence or absence of those antigens will be noted on the accompanying antigen sheet.  However, it is impossible to test for all those low frequency antigens (LFA) out there.  And unfortunately, antibodies to LFA are often far more 'common' than you would expect.  So, if you're getting an unexplained positive reaction with a reagent red cell it's probably due to an antibody against a LFA.  And the manufacturer is not going to be able to identify it; all they can do is withdraw it from use for the future.  these results are not false positive but unidentified (and probably unidentifiable) positives.  Your reference lab might be able to identify it if they have a good sample from the patient together with a sample of the cell.

As for reagent red cells with positive DATs when used in gel (Frenchie) - you will sometimes see positive reactions in IgG or poly AHG in cards if you put the reagent red cells on to the cards without any plasma, due to the fact that the cells are not meant to be used in that way.  Usually if you repeat with neutral plasma, the 'positive DAT' disappears.  If it doesn't, either there is a real problem with the cell (unlikely) or it has become contaminated in your lab.  And - Frenchie again - I would advise you against diluting 3% cells for use in cards.  You could be creating more problems than you think you are solving.

Another reason that you might see unexplained positives is antibodies to Bg.  As far as I know all manufacturers test their cells with a panel of anti-Bg antisera.  However, we all know how variable Bg can be.  You can test a cell with 20 anti-Bg and maybe only 1 of them is positive; and vice versa someone with a known anti-Bg won't react with all Bg+ cells.  So if you are seeing a fairly high number of unexplained positives, especially in pregnant women, then you shuld suspect Bg.

 

Beautifully written.

I have had one of these reactions . . . weak 1+ cell 2, neat panel is very clean, enzyme pretreated panel was a panagglutinin with a predilection for Rh(o)D+ cells (3+ vs 2+).

There have been discussions on the vagary of reactions in cell 2 over the past 3-4 years.  My take on these, which I have discussed extensively with Ortho, is:

 If I enzyme pretreat my panels  1) 75% of the time the reactivity is no longer detectable; 2)  28% of the time the R2R2 cells react 3-4+ and the patient is E negative. 3) 2% of the time I get interesting results (like the panaggl).

My belief is that the reactivity is valid for an HTLA or a naturally occurring, but weak, anti-E; I do not believe these are spurious reactions - if so they would not be just in the R2R2 screening cell . . .

23 hours ago, galvania said:

Can I make some comments about this type of reaction 'from the other side'.  It is easy to forget that reagent red cells come from real donors who have complicated antigens on their red cells.  The donors will be tested for as many antigens as possible, and the presence or absence of those antigens will be noted on the accompanying antigen sheet.  However, it is impossible to test for all those low frequency antigens (LFA) out there.  And unfortunately, antibodies to LFA are often far more 'common' than you would expect.  So, if you're getting an unexplained positive reaction with a reagent red cell it's probably due to an antibody against a LFA.  And the manufacturer is not going to be able to identify it; all they can do is withdraw it from use for the future.  these results are not false positive but unidentified (and probably unidentifiable) positives.  Your reference lab might be able to identify it if they have a good sample from the patient together with a sample of the cell.

As for reagent red cells with positive DATs when used in gel (Frenchie) - you will sometimes see positive reactions in IgG or poly AHG in cards if you put the reagent red cells on to the cards without any plasma, due to the fact that the cells are not meant to be used in that way.  Usually if you repeat with neutral plasma, the 'positive DAT' disappears.  If it doesn't, either there is a real problem with the cell (unlikely) or it has become contaminated in your lab.  And - Frenchie again - I would advise you against diluting 3% cells for use in cards.  You could be creating more problems than you think you are solving.

Another reason that you might see unexplained positives is antibodies to Bg.  As far as I know all manufacturers test their cells with a panel of anti-Bg antisera.  However, we all know how variable Bg can be.  You can test a cell with 20 anti-Bg and maybe only 1 of them is positive; and vice versa someone with a known anti-Bg won't react with all Bg+ cells.  So if you are seeing a fairly high number of unexplained positives, especially in pregnant women, then you shuld suspect Bg.

 

19 hours ago, goodchild said:

Beautifully written.

23 hours ago, galvania said:

I would advise you against diluting 3% cells for use in cards.  You could be creating more problems than you think you are solving.

 

This dilution of the 3% cells is the advice given to me by Ortho Tech Support.

20 hours ago, goodchild said:

On Thursday, February 18, 2016 at 10:08 AM, galvania said:

 And - Frenchie again - I would advise you against diluting 3% cells for use in cards.  You could be creating more problems than you think you are solving.

 

 

 

this is what our vendors are recommending (Ortho).  I pretty much use my Ortho panel to deal with scenarios like the w+ cell2 and RhIg anti-Ds.  I use other vendors' panels, diluted to 0.8%, for most of my antibody ID's.

I completely agree with the variability of Bg antigens on the red cell, as the most common cause of these types of reactions. Even though Ortho screens for these- they can come and go on the red cell in terms of their expression strength. We must not forget  a strong 'I' expression; a strong cold agglutination  w/ 'I' specificity -can be a common causal issue for these type of reactions-and something manufacturers don't routinely type for. Changing manufacturers will not solve the problem, as you'll note by doing research on this site- they are all plaqued by this sometimes .... The joys of blood bank- and the need for knowledgeable techs!!!

On ‎02‎/‎19‎/‎2016 at 11:12 AM, David Saikin said:

this is what our vendors are recommending (Ortho).  I pretty much use my Ortho panel to deal with scenarios like the w+ cell2 and RhIg anti-Ds.  I use other vendors' panels, diluted to 0.8%, for most of my antibody ID's.

I'm bringing back an old post here  ... If you dilute a 3% panel cell to 0.8% is there any additional QC you perform?  It is stated that the diluted cell suspension is stable for 24 hours - is this sufficient?  Thank you! 

Very interesting post - especially given that we are having current problems with Cell 2 also (R2R) with our Solid Phase RS3 strips on our ECHO.  We received a new lot# of strips last week and are doing better - just odd that it is cell 2 in both types of systems. 

When I was diluting red cells to 0.8%, I ran QC straight from the bottle for tube (because we always do QC for tube), then repeated with the diluted cells for gel. The QC on the 0.8% dilution is going to cover the entire process, including the dilution step, and the reagents. We made up fresh cells every 24 hours, as required by the manufacturer.

3 hours ago, AMcCord said:

When I was diluting red cells to 0.8%, I ran QC straight from the bottle for tube (because we always do QC for tube), then repeated with the diluted cells for gel. The QC on the 0.8% dilution is going to cover the entire process, including the dilution step, and the reagents. We made up fresh cells every 24 hours, as required by the manufacturer.

Thank you SO MUCH for the feedback!!  We perform QC on the 3% (tube method) upon arrival - did you dilute the entire panel every 24 hours for use?  Or only do so when needed... how did you decide which specific antibody to use as QC?  We will only be diluting as needed, mainly for select cells/rule outs.   

19 hours ago, BloodBanker80 said:

Thank you SO MUCH for the feedback!!  We perform QC on the 3% (tube method) upon arrival - did you dilute the entire panel every 24 hours for use?  Or only do so when needed... how did you decide which specific antibody to use as QC?  We will only be diluting as needed, mainly for select cells/rule outs.   

We diluted the antibody screen daily, panel cells as needed. QC antibody for the antibody screen was dilute anti-D and dilute anti-c. We wanted a 1-2+ reaction for QC, so diluted antisera accordingly. You could also use commercially available QC kits. For the panel cells, we selected a K+k+ cell for a positive control and a K-k+ cell for a negative control, testing with anti-K (polyclonal) diluted 1:20. In previous discussions about QC Malcolm suggested Fya or Fyb positive cells for a positive control since that antigen can deteriorate during storage. If you are using the diluted cells for select cells/rule outs, you could choose to use a cell positive for one of the antigens you are using the cell to rule out as your positive control with the appropriate antibody. A cell negative for that same antigen would be your negative control.