Jump to content

Anti-G????


Bet'naSBB
 Share

Recommended Posts

We have an Rh neg patient who has received 4 units of Rh neg RBC's and has made what looks to be a perfect anti-D.   We do not have a pre-transfusion sample - so the C typing is mixed field (in gel- not strong......more negative cells at the bottom of the column compared to positive cells at the top - like you might imagine in a patient who is C neg and received 1 unit of C pos blood......) leaving us to wonder if they're C pos or C neg.....  We typed the 4 units they received and one is C pos.  We "want" to say this is an anti-G - but, there's absolutely NO anti-C reactivity.  Not even with enzymes. DAT is negative. We've also scoured the few lit. resources we have and none of them address that an anti-G could / would do this.....  We even repeated the weak D's on the units...........all tested weak D neg.  Any insight??

Side note: We've checked about IVIG, other drugs - nothing.  They did get 2 units of A pos FP24 - but that, IMHO - shouldn't have caused any of this.

@Malcolm Needs??

Link to comment
Share on other sites


1 hour ago, Bet'naSBB said:

We "want" to say this is an anti-G - but, there's absolutely NO anti-C reactivity.

Reading between the lines, I believe you're saying that C+D- (r'r) panel cells are nonreactive, thereby excluding the presence of anti-C, If that's the case, and since said cells should carry the G antigen, it is very unlikely you're dealing with anti-G. Anti-LW may mimic an anti-D pattern by demonstrating reactivity only with D+ cells.

It's also very remotely possible that one of the donors carries a rare form of D-antigen that is not readily detected by typical commercial reagents. However, those are very rare and their ability to stimulate an immune response is not well understood.

Link to comment
Share on other sites

I agree ENTIRELY with the answer given by exlimey.

Anti-G usually (not always, but usually) reacts more strongly with the C antigen than the D antigen, so that R1R1 and r'r red cells would give stronger reactions than would R2R2, whereas both anti-D and anti-LW would react more strongly with R2R2 red cells than R1R1 and r'r red cells.

I agree that one of the units could express an unusual D type (I was caught out once in a pregnancy case when the dad had the unusual D type of RHD(L214F)-CE(7)-D - which I thought was rather unfair of him!).

Have you tried rr cord bloods against the patient's plasma/serum sample?  The LW antigen is expressed much more strongly on cord red cells than adult red cells.

Link to comment
Share on other sites

I've been wracking my brains over this one, but I have hit a brick wall.

If it is not an anti-LW, I can see no alternative to an anti-D (possibly caused by a previous pregnancy - if the patient is female [or, these days, possibly a transexual who is now a male], or by one of the donors having a very rare RHD mutation).

Somebody will now come up with an explanation that is quite simple, and I really should have thought of immediately!!!!!!!!!!!

Link to comment
Share on other sites

I was also thinking of a prior sensitization. A weird, barely detectable D+ phenotype may not generate a new immune response, but may be enough to reactivate the primed lymphocytes in an individual who's anti-D has faded into non-detectability. Tiny re-exposure and wham ! Nice, strong, clear-cut anti-D, apparently out of nowhere.

Link to comment
Share on other sites

16 hours ago, RRay said:

I've had this come up before with incomplete transfusion history (transfusions at another facility) and with IV drug use / sharing needles.  Occam's razor?

Agreed....history is always a wildcard.

I had a case once where there a teenaged male individual had antibodies to red cells (I can't remember the specificity) with no apparent transfusion history. Later questioning revealed that the person was part of a "Blood Brothers" group who routinely and ritually exchanged blood through self-inflicted cuts. Each to their own.

Link to comment
Share on other sites

48 minutes ago, exlimey said:

Agreed....history is always a wildcard.

I had a case once where there a teenaged male individual had antibodies to red cells (I can't remember the specificity) with no apparent transfusion history. Later questioning revealed that the person was part of a "Blood Brothers" group who routinely and ritually exchanged blood through self-inflicted cuts. Each to their own.

VERY good point.  When I was working at Westminster Hospital (many, many moons ago now), we came across a male Jehovah's Witness patient who swore blind that he had never been transfused, with one of the strongest polyclonal human-derived Fya antibodies I have ever seen.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

  • Advertisement

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.