Rh control

[SRTECH]

RH Controls when performing weak D testing; is Saline or 6% albumin acceptable?

Is it necessary to QC the 6% albumin daily? Would you use chech cells as a possitive control?

Also for AB pos patient; which is acceptable? 6% albumin or an autocontrol?

I've searched several of the previous threads and inserts and am still not sure

which is correct.

Thanks for your much anticipated answer!

[jill]

For an AB patient you can use 2 drops of saline with one drop of the patient cell suspension as your

control.

We us a commercially prepared Rh Control reagent. This would be better to use than 6% albumin because the maufacturer puts the same material, minus the Anti-D, as what is in the vial of Anti-D.

The Rh Control reagent can be QC'd daily with the other reagents used for typing.

[clmergen]

It depends on your manufacturer. Immucor makes a D control for use with it's monoclonal Anti-D reagents. Ortho package inserts says that a D control is not necessary but if the customer requires the use of one, then the use of 6-8% albumin is acceptable.

[David Saikin]

I use 6-8% albumin; theoretically you only need to run Rh ct when you have a pt type as AB+. The protein concentration of the anti-A or anti-B is equivalent to that of the anti-D (if you are using monoclonal abs). You should run the control if performing weak D testing (in case the pt has a positive DAT).

[kharbert]

I would like to ask if we can clean up our terminology. Due to the legacy of Rh testing history, we continue to use the term "Rh control" for what is now truly a monoclonal control for those of us using monoclonal reagents. Antisera package inserts instruct us to perform a monoclonal control any time the blood type is presumably AB positive. The requirement to perform a control when patient testing yields a presumed AB positive result is because ALL of the cell testing (with Anti-A, anti-B AND anti-D) is suspect because we can't know whether the agglutination reactions were the expected antigen:antibody reactions, or if the cells agglutinated for another reason. We then run a monoclonal control--a solution identical to the A, B and D antisera, but without added antibodies. The monoclonal control in this situation, then, is a control for the A, B, AND D testing, and is not an "Rh control". A positive reaction with the monoclonal control invalidates A, B AND D testing because it demonstrates that the cells agglutinate in the absence of antibodies.

Thanks, don't mean to rant, but our history, expertise and extensive experience is getting in the way of accurate terminology in this instance.

[Malcolm Needs ☆]

I could NOT agree more kharbert.

Correct terminology in everything prevents mistakes (my first ever thread - I think).

[David Saikin]

I understand What you are saying but I tend to disagree . . . I do not run a "monoclonal" control when I use monoclonal antibodies directed against other blood group system ags (K, Jk, MN, P, . . . ). I use 6-8% albumin ONLY to validate my Rh(o)D typing - and I use it all the time when/if tube testing is done. (Knowing human nature, I may be tempted to NOT run it when necessary. It is also a moot point when using and ABD Reverse card). With decades of experience, I think I have seen an i.s. positive Rh Control 1 time and that was when it was "high protein" anti-D (30% albumin). We are not speaking of Weak D's where the pt has a +DAT, rather that "spontaneous" agglutination caused by immunogloblin coated cells in a protein environment. Maybe we should call it a "protein" control.