mini panel for passive Anti-D

[kpend]

Hello,

 

I am seeking to understand how a mini-panel is used in patients suspected of a passive Anti-D from Rhogam.

Our OB patients almost all have a Type and Screen ordered on admit for delivery. Since we are gel users, we pick up a lot of what we suspect to be anti-D from the antenatal rhogam. We perform the screen and then an 11 cell panel, reporting it out as an anti-D, Rhogam given XX/XX/XX. We are fortunate to have easy access the the patient's Rhogam history in most situations.

 

1. What is a mini panel?

2. Can I make a mini panel from the Immucor 16 cell panel? What about an Ortho 11 cell panel?

3. Is a mini panel ever used in situations other than passive anti-D?

 

Thank you

[galvania]

Basically a mini-panel is (usually) a 6-cell panel where at least 5 of the cells are D negative, and between them contain all the relevant antigens needed to detect  antibodies that are clinically relevant in pregnancy.  they are primarily used where you know that the patient has received prophylax, and the object is to know whether the patient has any other antibodies present.  If you use just a 3-cell screen, 2/3 will be positive.  Obviously if the minipanel is positive, then a full panel has to be carried out to identify the additional antibodies.  Other than that the minipanel can of course be used as a source of additional cells when carrying out antibody identifications.

[Auntie-D]

It doesn't have to be even as big as 5 or 6. We use a 2 cell rr screen. It doesn't eliminate the possibility of Anti-C or Anti-E so if blood was needed you would need to crosasmatch C-E- units. With the scoring if it greater than 2+ you would expect to be due to an allo antibody and send for quantification then repeat at 3 months.

 

This is the link to the product insert

 

http://hospital.blood.co.uk/media/2121/3e3f3172-7b60-42df-8197-cf0ec6d22dd5.pdf

 

Edited November 12, 2014 by Auntie-D

[jayinsat]

Basicallly, a mini-panel is running the 4 cells with the "@" in the "SPECIAL ANTIGEN TYPE" column on the ORTHO 0.8% PANEL A panel.  These cells are r'r,r"r, and 2 rr cells that, if all 4 are negative, will rule out all other significant systems homozygously.  It is the same thing as running only the minimum number of rh negative panel cells to rule out all other antigen systems. 

[AuntiS]

We set up a 5 or 6 cells panel for patient's known to have been given RHIg.  It depends on the panel in use - but we set up 1 D+ cell and then 4-5 additional D- cells to eliminate the rest of the commonly significant antibodies on the panel.  We might skip the M or N if they won't all fit in 5 cells.  We right the cells on the plastic panel holder so they are readily available when needed

[goodchild]

In my experience the "@" symbol D-neg cells rarely cover panel cells with homozygous expression and aren't effective as a mini rule out panel. I'm not really sure what Ortho is thinking with this one. For example with our current lot if you went by the @ symbol panel you wouldn't have a rule out for Fy^a, Jk^b, or S, even if you had included the three cell from the antibody screen.

 

In the past we were proactive and marked off the suggested cells to run on a blank antigram (preferrably one that included the 4 cell, autocontrol and 4 more cells so it would fit on one card), made copies and left it in a "Use for RhIg folder" but that's fallen into disuse now that we no longer have any new associates.

[David Saikin]

I select  5 cells to use in r/o RhIg anti-D.  I do not select from an Ortho Panel (I get .

[mollyredone]

I have discovered that too with the @ cells on the Ortho panel.  Sometimes it does rule everything out with a homozygous cell, but not all the time.

 

Here's another question.  We have a special antibody for Rhogam recipients, D residual Rhogam, which is resulted out only if we have a definite date for Rhogam.  With a real anti-D, we would always do a gel crossmatch.  We are doing that with Rhogam as well, even though the panel is negative.  Is it safe to discontinue gel crossmatches if we have negative antibody screens after that?  We had a patient who was last in with Rhogam in 2005, but has had three negative screens this year.  I feel it is safe to revert to an immediate spin and delete the antibody.

 

Thanks!

 

Mari

[tbostock]

We use the Ortho panel with the @ symbols with no problems.  Here's why I don't care so much that it doesn't rule out everything with a double dose/homozygous expression:

 

Passive Anti-D isn't really an "antibody" as far as our rule out "rules" go.  We have information that the patient received the RhIg, which confirms the reactions in the screen.

 

If we detect an antibody, we are mostly concerned with identifying it.  If they have a history of antibodies, we are mostly concerned with looking for new ones.  With an "interference", like a RhIg or non-clinically significant cold agglutinin, we are just trying to get it to go away.

 

If you look at your screening cells, we are ruling out with single dose cells every single day.  So I look at the @ cells as a screen of D negative cells.  I'm not really considering them rule outs in the true sense.

[Malcolm Needs ☆]

Hi Mari,

 

I would agree with you - disregard the passively acquired anti-D.

 

godchild and Terri - I noted that you both used the term "homozygous expression".  Yee ha!  My moaning about correct terminology must be getting through, even if it is only to stop me moaning again!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

:D :D

 

[tbostock]

I did it just for you Malcolm! And any of my SBB instructors that may be lurking.  HAHAHA...

[MeganPLT]

We use the 16 panocell from Immucor and it has 3-4 cells bracketed for the use of a "mini-panel" similar to the @ for ortho.  However - if you look at the note at the bottom of the immucor panel it says this about the bracketed cells:

"In those instances where a patient's serum is known to contain anti D, it may be desirable to perform antibody screening tests with D negative red cells. The panel cells whose vial numbers are set off by brackets [()] can be used together to form a three or four vial D negative antibody screening reagent. All bracketed cells must be used to construct a complete screening reagent"

.

The intent of the bracketed panel is not to perform antibody ID but to be used as an additional extended screen (especially if you use a 3 cell screen where cell 3 will be positive in cases of RhIg administraion). So we perform this "mini panel" as a screen - not as antibody identification.  Remember - Screening cells are not required to have homozygous expression for antigens.  Big distinction so I think people may be trying to use this for more than what it's intent is really for....like tbostock described above.

[goodchild]

Hi Mari,

 

I would agree with you - disregard the passively acquired anti-D.

 

godchild and Terri - I noted that you both used the term "homozygous expression".  Yee ha!  My moaning about correct terminology must be getting through, even if it is only to stop me moaning again!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

:D :D

 

Contrary to popular belief in my local area, I love being corrected and learning from my mistakes. I hate appearing as dumb as I really am!

 

Haha, thanks Malcolm.

[John C. Staley]

We stopped doing routine T&S on all OB patients.     This took care of 99% of the problems. 

[Auntie-D]

We stopped doing routine T&S on all OB patients.     This took care of 99% of the problems. 

 

What about those that have >2+ expression though that may have developed an antibody late in pregnancy? Those we send for quanification and do follow up.

[CMCDCHI]

We stopped doing routine T&S on all OB patients.     This took care of 99% of the problems. 

Do you have a big L&D service?  We do a T&S on all L&D admissions.  This saves us time (and anxiety) when it comes to a delivery going bad.  It also makes our RhIg evaluations faster.  I'm all for eliminating unnecessary work, but I can't imagine not doing a T&S on our OB patients.

[mollyredone]

Most of our OB docs are doing OP T&S on early prenatal visits.  This is a big help.  We get Draw and Hold on normal deliveries and T&S on C-sections.

[John C. Staley]

Do you have a big L&D service?  We do a T&S on all L&D admissions.  This saves us time (and anxiety) when it comes to a delivery going bad.  It also makes our RhIg evaluations faster.  I'm all for eliminating unnecessary work, but I can't imagine not doing a T&S on our OB patients.

 

Yes, we had a very busy labor and delivery service to include a 35 bed NICU.  Also, we performed virtually all of the prenatal testing and antenatal RhIG distribution for the docs who delivered at our facility.  Of course not everyone had prenatal care either with our docs or at all and they recieved any testing ordered at admission. We still had a sample collected and labeled at admission on all L&D patients but only ran the testing as ordered.

[CMCDCHI]

The first story in this article was at our facility.  Needless to say, I don't think we will be cutting back on our OB T&S anytime soon.  This one is too fresh (though it was before my time here).

http://www.5280.com/magazine/2013/08/hero-work?page=full

[L106]

The first story in this article was at our facility.  Needless to say, I don't think we will be cutting back on our OB T&S anytime soon.  This one is too fresh (though it was before my time here).

http://www.5280.com/magazine/2013/08/hero-work?page=full

 

Oh, wow!!  Thanks for the article.  I will share with my staff.  So glad that your event had a positive outcome.  Incredible!!

[Auntie-D]

It's such a happy story but so sad that the woman saved feels cheated and disappointed that after her ordeal the baby looks like her father.

[DPruden]

The first story in this article was at our facility.  Needless to say, I don't think we will be cutting back on our OB T&S anytime soon.  This one is too fresh (though it was before my time here).

http://www.5280.com/magazine/2013/08/hero-work?page=full

I remember that day!

[CMCDCHI]

We had another suspected amniotic fluid embolism hours after I posted that article.  Amazingly, mom is doing well and is being moved out of the ICU today.  

[Ruth Hugeback]

This topic thread is over a year old but it is a perfect place for my question. 

We are a small, critical access hospital with an OB department, surgery, ICU and ER.  We do not perform any antibody identification.  All positive antibody screens are sent to another hospital 2 hours away for investigation. 

As MeganPLT noted, the @’ed or bracketed cells from the panel are not intended for ABID but as an appropriate method of detecting unexpected antibodies – when the patient is known to have anti-D either passive or immune.   If we could use a D-negative antibody screen we could save critical hours.  We use Capture strips for antibody detection and could get a few panel strips to use for this purpose. 

Is a D-negative antibody screen acceptable for a facility which does not perform antibody identification?

[goodchild]

This question brought to mind Title 21 CFR 660.33: 

"Group O Reagent Red Blood Cells used in the detection or identification of unexpected antibodies shall include at least the following common antigens in each lot of the product: D, C, E, c , e, K, k , Fy a, Fy b, Jk a, Jk b, Le a, Le b, P1, M, N, S, and s ."

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=660&showFR=1&subpartNode=21:7.0.1.1.8.4