Elution, yes or no?

[Peggy]

When a physician orders a DAT, and it is IgG positive, does your institution automatically perform an elution if the patient has an 'OK' hemoglobin and no record of transfusion? I assume in most cases, the physician is looking to diagnos/monitor. I am on the fence with this one, and not consistent.What is everyone else doing?

[Likewine99]

Our pts only get elutions when the autocontrol is pos on a panel AND the pt has been tx in the last 21 days.

I've had docs ask for this and invariably the elution is neg. We use gel for our panels/autocontrols.

[David Saikin]

Anti-IgG positive is automatic elution at my place.

[JOANBALONE]

If this is the first time we are seeing this patient our medical director would like us to do an eluate.

[bpkelly]

We only perform the elution if the patient has been transfused and/or if the physician specifically orders the eluate.

[Eagle Eye]

positive DAT---we do elution.

[janet]

We only elute if the patient has been transfused......In anyone's experience has an elution done more than make alot of work when it was an auto-antibody or drug/disease induced?

[GilTphoto]

I'm really surprised that so many do automatic eluates! We only do them if the patient has been transfused within the past 3 months, or is pregnant.

I can understand the rationale in shortening the 3 month period, since after a few weeks the antibody response should be strong enough to be detected in the plasma.

The only purpose in doing a DAT, is as an indicator of a hemolytic process going on. What information can be gotten from the elution if not transfused recently?

Positive DAT can be caused by:

1. Antibody response to transfusion or pregnancy. An antibody may be coating transfused cells and be undetectable in the serum.

2. Passively aquired antibody

Newborns: (HDN). We only do elutions on newborns if the mother has a significant antibody capable of HDN and the baby is antigen positive. We don't do elutions when the positive DAT is likely to be ABO related (O mother has an A or B baby). In both cases, the doctor only has to monitor the bilirubin, to see whether exchange transfusion is indicated, or more time under the bili light.

Adults: If the patient has been transfused blood other than type specific such as an AB patient receiving many A cells or platelets, and the elution using O cells is negative (Gamma Elu-kit), a Lui-Freeze/Thaw elution should be done using A + B cells, to rule out anti-B (or anti-A if B cells were given). While anti-A,B passively acquired this way, causes a positiver DAT, it rarely causes a hemolytic anemia.

3. Drug Induced - A complete drug history should be obtained. Drugs taken within the past 3 months should be considered. While many drugs cause a positive DAT, only a few cause a hemolytic anemia. The eluate may be all positive, but is usually all negative. While elutions can be performed with drug coated cells, no useful information is obtained by doing the elution. If the doctor suspects a drug induced hemolytic anemia, the patient will respond to elimination of the drug, or sometimes reduction in dosage.

4. AIHA (Auto-immune hemolytic anemia - usually the panel is all positive too. The eluate will also be all positive. Could be warm, cold or a mixture of both. No useful info is obtained from this eluate either. Adsorptions have to be done to rule out underlying significant antibodies. Other indicators of hemolytic anemia should also be tested including Hgb, LDH, K, haptoglobin, immunoglobulins, etc. It

WARM ANTIBODY

1. Idiopathic

2. Systemic Lupus erythematosis

3. Evan's syndrome (anti-platelet and other hemolytic antibodies)

4. Chronic lymphocytic anemia

5. Drugs (methyldopa)

COLD ANTIBODY

1. Idiopathic cold agglutinin (or hemagglutinin) disease (CAD or CHD) - Autoanti-I that does not prewarm away easily (without cold absorption) and has a titer >1000. Would recommend a blood warmer in this case only! (not for the routine cold autos that prewarm away). Complement is positive.

2. Infectious mononucleosis - usually an autoanti-i can be demonstrated in the serum (stronger with cord cells, than adult cells).

3. Paroxysmal cold hemaglobinuria PCH - (rare) usually seen in children. Complement is positive. Serum contains an anti-P (not P1) a bi-phasic hemolysin demonstrated by the Donath/Landsteiner test.

4. Lymphoma

Diagnosis related positive DAT

Several diagnosis' have been associated with a positive DAT:

RETICULOENDOTHELIAL NEOPLASMS

1. Chronic lymphocytic anemia

2. Hodgkin's Disease

3. Non-Hodgkin's lymphoma

4. Thymomas

5. Multiple Myeloma

6. Waldenstrom's macroglobulinemia

7. LIver Disease

COLLAGEN DISEASES

8. Systemic Lupus erythematosis

9. Scleroderma

10. Rheumatoid Arthritis

INFECTIOUS DISEASES

11. Childhood viral syndromes

12. Maleria

13. Mycoplasma pneumonia infection

14. Infectious mononucleosis

IMMUNOLOGIC

15. Hypogammaglobulinemia

16. Dysglobulinemias

17. Immune deficiency syndromes

GASTROINTESTINAL DISEASE

18. Ulcerative colitis

BENIGN TUMORS

19. Ovarian dermoid cyst

POSITIVE DAT - Cause unknown - As many as 10% of hospital patient's may have a positive DAT with no known factors, and without a hemolytic anemia.

As far as waiting for the doctors to order an eluate, I think you'll be waiting a long time! I don't think most of them know what it is. I've never had a doctor order one in my 33 years doing lab. We add the order ourselves when it's indicated

Edited August 28, 2008 by GilTphoto
typos

[kate murphy]

If we've never seen the patient, we do an eluate.

Otherwise, only if they have been transfused in the past 3 months.

[jalomahe]

If we are doing the DAT due to a positive antibody screen in anticipation of possible transfusion we will do an eluate IF it is IgG. That way we have a baseline to compare to when/if we have to do the patient in the future.

If we are doing the DAT where the physician has ordered it and the patient has no transfusion history, then we do not perform an elution. The physician would have to request one. The physician ordering an elution, as you might imagine, rarely happens.

Just remember that however you decide to set your policy up you must have it clearly defined as to when you will perform an elution (or any test) reflexively based on other testing and that information needs to be communicated to physicans that use your lab. Under federal guidelines, you cannot perform testing without a written order from a licensed practioner. We do this by including in our Laboratory User's Manual a table that lists "Reflexive Testing" and it gives the what the primary order is and then what the reflexive order would be and then under what circumstances the reflexive order is performed i.e.

Primary Reflexive Circumstance for Reflexive

Antibody Screen Antibody Identification Antibody Screen is positive

This reflexive order list is circulated to the medical heads of all departments and distributed to the physicians we have outreach contracts with.

jlmh

[omer alsaweed]

If DAT positive & IgG positive . First thing check Pateint Medication & Do antibody screening (ABS) If ABS positive run Panel. No need to do Eluate if the patien not transfused Blood on three month past or not pregnents.

[jhaig]

We only do eluates on a positive DAT if the patient has been transfused within the previous three months. If I asked one of our physicians what an elaute is, they'd probably say that's it's some kind of hooved mammal...:cool:

[Mabel Adams]

Wow, Gil. What a great posting on DATs. I am going to email it to some newbies as a great source for their education.

[Philip Thornton]

Wow, Gil. What a great posting on DATs. I am going to email it to some newbies as a great source for their education.

Exemplary justification! I've printed this off for the new techs. Our facility like yours only does an elution if recently pregnant or transfused.

[NedB]

Reflex elutions is our course of action too, when the Patient has been transfused or been pregnant within previous 90 days. The 90 days is probably overkill since most antibodies will show on the antibody screen much sooner. But, I had not thought of telling our outreach clients this would be automatic - thanks.

[Marilisa]

When a physician orders a DAT, and it is IgG positive, does your institution automatically perform an elution if the patient has an 'OK' hemoglobin and no record of transfusion? I assume in most cases, the physician is looking to diagnos/monitor. I am on the fence with this one, and not consistent.What is everyone else doing?

We only perform an eluate if the patient has been transfused within the last 14 days.

[sassai13]

Hello Everybody! This is my first time that I'm replaying to somebody question.

First I would like to introduced my self my name is Saša and I work for Blood Transfusion Center of Slovenia (Europe), working as Lab Technition in Reference laboratory.

We do elution when autocontrol and DAT is positive, especially when IgG is positive. I agree with Janet, I think if the patient hasn't got transfusion lately (or being pregnant), elution is not neccesary.

S.

[Karen Olsen]

We would only perform the eluate if the patient had been transfused or was pregnant in the last 3 months. Or if a physician specifically ordered it - but that would never happen!

[rcurrie]

I vote nay on automatic elutions. Get a history if the DAT is positive, and consult with the physician.

BC

[Joanne P. Scannell]

We do an elution only if the patient has been transfused. Q: What are you looking for? A: Antibodies that you will do something about in the future. In other words, WE need to know! (The MD really doesn't care what it's name is ... just get compatible blood next time.)

If the patient hasn't been transfused, your eluate will be 'all cells positive' or 'all cells negative' ... so what's the point?

AND if you happen to find one of those auto-antibodies that looks like an Anti-E or such ... you are only just going to confuse the world when it comes to transfusing the patient later. (The proper answer is you don't honor it. So again, what's the point?)

Ok, I agree ... there may be times when an eluate is useful ... such as if the MD wants to determine if a drug is causing the problem. But again, if he/she is suspecting that, he/she will either d/c the medication to clear the positive DAT or wait until the patient develops symptoms and THEN d/c the medication. We don't test eluates against drugs here. So, if that is ever requested, if we cannot convince the MD he doesn't need it, we'd send it to a reference lab that can perform the tests appropriately.

I guess my simple answer to your question is 'NO!'.

[Sandy L]

We would only do an elution if there is history of transfusion within the last 4 weeks. I cannot find the refence now, but John Judd published a study (my recollection if in Transfusion and some time ago) regarding detection of alloantibodies post transfusion in eluates. His findings were that after 4 weeks the antibody that is recovered in the eluate is also detected in the plasma so that nothing is gained by doing an eluate beyond that time frame. That was there policy at UMich I think

[tburns]

Our policy is to perform an elution only when a patient needs an rbc transfusion, and if the patient has received blood w/in the past 3 months.