extra testing to ID passive anti-D

[Mabel Adams]

At my new workplace the policy is to do a tube antibody screen of a 1/4 dilution of plasma to determine if a patient that has received RhIG in the past 6 months should be considered as having passive rather than active anti-D. If negative at a 1/4 dilution it is determined to be RhIG, if positive it is titered as a likely anti-D.

[David Saikin]

I guess you can "assume" you are detecting passive anti-D. I let the docs make that decision. We report anti-D and recommend repeat in 3-4 months afterlast dose of RhIg to verify active vs passive sensitization. My docs never have done the repeat.

[krichards]

We do a full workup antibody ID for our Rhogam Ds. If they have a known history on their chart of RhIG in the past few months, then we report the antibody as "Anti-D, possibly due to Rhogam". We leave it to the docs to follow up with a repeat should they have any questions regarding passive or active immunization.

[John C. Staley]

We ID the anti-D and ask the patient/Dr./Nurse if the patient has had RhIG recently. If the answer is yes we result it as Anti-D Possibly Due to RhIg and add a comment that the patient had received antenatal RhIG.

If the answer is no we result it as an allo anti-D and treat it as the real deal from then on.

If we can not get an answer we, well we've never not received an answer one way or the other but if we did we would probably result it as an allo anti-D and treat it as the real deal from then on.

[Mabel Adams]

I should point out that we do the gel screen and identify anti-D first before proceeding to testing the 1:4 dilution. Sorry for the confusion.

[Eagle Eye]

We do similar to John. If we ID anti-D, we check with the floor for the history of RHIg and if patient received RHIg we do not do any further testing. If we do not get a hold of RHIg history then we do anti-D titer.

[L106]

We handle this the same as krichards and John Staley do.

However, if we are told that the pt has not received RhIG, we report out a comment "Pt has not received RhIg recently, per Dr. Soandso's nurse Nancy." (And it almost always turns out that the pt had received RhIg and Nancy just didn't know where to look!)

[Likewine99]

We run the 2 cell screen, call the OB clinic or L&D and get documented date of RhIg administration. Then run the Ortho A panel with the 6 cells designated with the @ sign and one more D+ cell.

This gives us our required 3 D+ cells and 4 D- cells that also r/o K,E,C. We charge for the screen and the full panel, our CDM doesn't have a code for an abbreviated panel. We call the antibody, "passive due to RhIG administration".

If not able to document RhIG we do the whole workup like it was a "real" anti-D and call it anti-D.

[GilTphoto]

If the anti-D is < 2+ at IAT only and the patient has received RhIG, we report passive.

If it reacts at IS or 37C, or is 3+ or stronger, we titer.

<= 1:4 - we report passive anti-D

> 1:4 - we report immune anti-D

[webersl]

We use gel Selectogen for the screen. If both cells positive, we run the few marked cells (@ - to rule out everything but D) on gel Ortho A panel. If we've issued RhIg recently, we call it "D presumably due to RhIg". If we haven't issued RhIg, we call the floor and ask if the pt has received it. If it cannot be verified that the pt received RhIg, we do a titer and report the results of the titer.

[Mabel Adams]

If the anti-D is < 2+ at IAT only and the patient has received RhIG, we report passive.

If it reacts at IS or 37C, or is 3+ or stronger, we titer.

<= 1:4 - we report passive anti-D

> 1:4 - we report immune anti-D

Are these reaction strengths LISS/tube, gel or ???

[csjuarez]

After documenting that the patient has received RhIg, we place a comment on the Anti-D result indicating this fact (de facto assuming the Anti-D is due to the RhIg adminstration). We do not perform additional testing to try to differentiate the passive anti-D from that actively produced by the patient.

[Jeni Matsunaga]

We perform a full antibody identification and get a patient history of recent Rhogam administration. It is reported as "Anti-D, probably due to Rhogam administration on (date of shot)."

[adiescast]

If we have a negative screen from earlier in the pregnancy and a date of RhIg injection, we assume the anti-D is passive and report it as "anti-D due to RhIg given [date]". If we have a date of RhIg injection, but no negative screen history from this pregnancy, we hedge the bet and report it as "anti-D possibly due to RhIg given [date]" (but don't titer). If we have no history of RhIg (either we know none was given or we cannot elicit a history), we assume it is an active antibody and report it as anti-D. Titer is performed if the woman is still pregnant but not if she has delivered.

[BSIPHERD]

We do a 1:8 dilution and a Modified Antibody Screen (to rule out other antibodies). If the 1:8 is negative and the patient has a history of receiving RhIG recently, we report

Probable Passive Anti-D is present in the plasma.

It is thought to be passive because the titer is

less than 8 and the patient received Rh Immune

Globulin on MM/DD/YY.

[kelliott]

After ID of anti-D in D negative woman of child bearing age we investigate for RhIG administration. If RhIG has been admininstered within the previous 5 months [gel technique used for ABS] we report "results consistent with RhiG administration, administered XXXXXX."

[GilTphoto]

Are these reaction strengths LISS/tube, gel or ???

tube method

[GilTphoto]

We actually had an interesting case related to this poll.

A pregnant mother can in at term with an anti-D reacting 2+ at IAT and one cell that reacted at 37C.

Titer was 1:16 score=43. She had received RhIG at 5 and 7 months. This was her 3rd preg.

Her baby had a positive DAT with anti-D in the eluate. Bilirubin rose from 3 to 9, over 3 days, then decreased.

The mother also had a positive Fetal Screen and K/B. ratio=0.0043.

Just in case the high titer was due to receiving 2 doses of RhIG, we played it safe and gave her an additional 2 doses.

Just wondering what everyone else might have done. Would anyone call it an immune anti-D and not give RhIG?

[John C. Staley]

I don't think I would be willing to call it an allo anti-D until the patient was about 6 - 8 months from the last RhIG injection and still testing positive.