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Antibody Screen before Issuing RhIg


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Hello,

 

What are your policies for requiring an antibody screen prior to issuing RhIg? Is the policy different for ED patients vs clinic patients?

 

If you have a blood type on file already, do any of you not require a sample for a screen in an ED situation where an Rh Neg mother gets an order for RhIg?

 

It seems that in almost all cases you will issue RhIg regardless of what the antibody screen result is? Is the point of the screen to have a "clean" pre RhIg sample in case there is a need to titer?

 

Thanks in advance,

 

Jesse

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If a patient comes through the emergency department and a request for RhIg has been placed, we would issue the RhIg regardless of whether we have a type on file. They sometimes place an order for a blood type but we have no requirement for this to be done.

The nursing units and the laboratory have different IS systems and so the floors may actually have a blood type somewhere in the patients file (for instance like prenatal workups) and we would not know.

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I agree with Dansket.  There is too much insurance card swapping and sharing going around to rely on a historical type, even if andministration of Rhogam would not necessarily be that harmful.  We require a current type for everything except emergency release/massive transfusion and even then we would like to a specimen sooner than later so we're not pouring out ON for child-bearing females.

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3 hours ago, bowerj1 said:

Thank you. I see what you mean about a current type. Myoriginal question was do you require an antibody screen prior to issuing RhoGam?

 

Thanks,

 

Jesse

We don't require an antibody screen test result prior to or after issuing RhoGAM.

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13 hours ago, John C. Staley said:

If I remember correctly we did not require an antibody screen if we had a record of a negative result during the current pregnancy. Otherwise one was performed.  At least that's what I seem to remember.  :confuse:

Agree with John.  We would want to know that we had a negative screen on her at one time during her current pregnancy before RHIG administration.   History from another facility was acceptable.  If time was an issue, we would issue RHIG and continue with screen.   

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27 minutes ago, BldBnker said:

According to AABB Standard 5.30.2 part 2; "the woman is not known to be actively immunized to the D antigen."  We perform an antibody screen, along with an  ABO/Rh on a current sample before issuing a Rhogam. This is for ED patients and LD patients.

AABB Standards only apply to AABB accredited facilities.  Is there a standardized protocol provided by the AABB to determine whether or not a woman is actively immunized to the D antigen then anti-D is identified in her blood sample?

Edited by Dansket
added phrase
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At what point do you decide that RhIg that has been administered prenatally is sufficient if the patient has a miscarriage or trauma?  I would assume the fetus was Rh positive and give another dose to cover the bases.

But like Goodchild, pharmacy issues RhIg and we may not even know about it if we wanted to do a screen.  There is a clue if the ED orders an ABO/Rh on a young female, but that's all they order and  occasionally they just give it based on patient information!

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5 hours ago, Dansket said:

AABB Standards only apply to AABB accredited facilities.  Is there a standardized protocol provided by the AABB to determine whether or not a woman is actively immunized to the D antigen then anti-D is identified in her blood sample?

Dansket, I am not sure I understand your question.  That is the standard AABB protocol.  You perform an antibody screen to determine if the woman has already been immunized to the D antigen (ab screen neg for Anti-D).  We are AABB accredited.  There would be no need to give Rhogam if the patient already has Anti-D.  Even if the patient receives a prenatal Rhogam, a postpartum Rhogam is required (if the baby is Rh pos) to provide adequate protection to the mother.  We also perform Fetal Screens (FMH) tests to ensure that 1 vial of Rhogam is adequate.  We probably have 4 or 5 patients a year that require additional Rhogams due to larger than normal fetal/maternal bleeds.

Hope this helps! 

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1 hour ago, Dansket said:

Do all feel that performing/charging for an ABO type on the mother as part of an antepartum or postpartum RhoGAM work-up is pertinent information and justifiable?

We perform a Type and Screen on all patients presenting to the Labor Room (just one per admission) even if there is a historical type.  That is what is used to determine Rhogam candidacy.  We don't do a "post-partum" Type and Screen. We perform a Fetal Screen (FMH) on a post-partum specimen.   

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39 minutes ago, BldBnker said:

Dansket, I am not sure I understand your question.  That is the standard AABB protocol.  You perform an antibody screen to determine if the woman has already been immunized to the D antigen (ab screen neg for Anti-D).  

If a positive antibody screen is detected per your protocol and anti-D is identified in the "pre-partum" blood sample, how do you determine if the anti-D identified represents "active immunization to the D antigen" or "passive immunization due to a recent RhIg injection" in the absence of any record of recent RhIg injection.

I'm not aware of any serological test that all experts agree will definitively differentiate between active and passive immunization in all situations.  If there is such a publication I would like the reference.  Malcolm please advise.

Edited by Dansket
revised wording, added last sentence
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For antepartum we perform a quick blood type and issue the Rhogam prior to performing the screen.  For post-partum - if we have a type and screen that admission we only perform the fetal screen and/or K-B prior to issuing the Rhogam.  Our LDR usually only orders blood types upon admission, so in that case we would perform the screen prior to issuing the Rhogam as well.

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15 hours ago, Dansket said:

If a positive antibody screen is detected per your protocol and anti-D is identified in the "pre-partum" blood sample, how do you determine if the anti-D identified represents "active immunization to the D antigen" or "passive immunization due to a recent RhIg injection" in the absence of any record of recent RhIg injection.

I'm not aware of any serological test that all experts agree will definitively differentiate between active and passive immunization in all situations.  If there is such a publication I would like the reference.  Malcolm please advise.

We call the OB clinic for that patient and ask if and when prenatal Rhogam was given.  We document that on the patient's record.  Usually, prenatal Rhogam yields a weak Anti-D.  We do most of the prenatal work-ups for out patients since the clinics use our lab. The initial antibody screen is usually negative. If there is a question about passive vs. active Anti-D, a Rhogam is given (to err on the side of caution).

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"If there is a question about passive vs. active Anti-D, a Rhogam is given (to err on the side of caution). "

 

That is sort of what I was getting at. At our facility we do not require a new ABO\Rh test result each time RhIg is issued. We will issue with an historical Type (we do this for yellow products as well). Our current policy says that we "should" perform an antibody screen prior to issuing RhIg, for example to an ED patient. This is where I am seeking to clarify the SOP. I know that RhIg should not be administered to a patient that has been alloimmunized to D. But practically how do you determine active vs passive D, especially when you have a patient miscarrying in the ED and time is limited. Since it seems prudent to err on the side of caution and give RhIg regardless, I'm having a hard time seeing the value of the antibody screen test, since it seems RhIg would be issued regardless of the result.

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On ‎3‎/‎23‎/‎2017 at 8:27 AM, BldBnker said:

According to AABB Standard 5.30.2 part 2; "the woman is not known to be actively immunized to the D antigen."  We perform an antibody screen, along with an  ABO/Rh on a current sample before issuing a Rhogam. This is for ED patients and LD patients.

I'm not understanding how performing an antibody screen determines whether or not "the woman is not known to be actively immunized to the D antigen" meets the AABB requirement.  If I understand correctly you perform and antibody screen and do antibody identification, and if anti-D is identified (in the absence of a record of recent RhIG injection) you ignore that finding and give RhoGAM.  

In our process, we do an Rh type only and if patient is Rh negative and in the absence of a record of recent RhIG injection, we issue RhoGAM.  So for this hypothetical patient, we both come the same conclusion and issue RhoGAM.

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  • 2 months later...
On 3/23/2017 at 6:27 PM, Dansket said:

If a positive antibody screen is detected per your protocol and anti-D is identified in the "pre-partum" blood sample, how do you determine if the anti-D identified represents "active immunization to the D antigen" or "passive immunization due to a recent RhIg injection" in the absence of any record of recent RhIg injection.

I'm not aware of any serological test that all experts agree will definitively differentiate between active and passive immunization in all situations.  If there is such a publication I would like the reference.  Malcolm please advise.

At my prior facility we used to constantly get patients with positive antibody screens due to antepartum RhIG. In order to help differentiate between passive and active immunization, we performed a 1:4 titer on the patient's plasma. If the titer was greater than 4, we would suspect active vs passive. We never had one over 4 as far as I can remember. I don't recall were they obtained the reference material, but they are AABB, FDA, CAP, and JC accredited. 

Hope this helps.

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14 hours ago, seraph44 said:

At my prior facility we used to constantly get patients with positive antibody screens due to antepartum RhIG. In order to help differentiate between passive and active immunization, we performed a 1:4 titer on the patient's plasma. If the titer was greater than 4, we would suspect active vs passive. We never had one over 4 as far as I can remember. I don't recall were they obtained the reference material, but they are AABB, FDA, CAP, and JC accredited. 

Hope this helps.

In uk if quantification level is 0.4 IU/mL or above we consider as a immune anti-D and we do not issue RhIg.  However if lady comes in ED we perform Group and antibody screen before we issue RhIg.

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