Tag: Immunohematology

Immunohematology testing and processes

Ortho D Typing Reagents for Patients

drzeyd

Policy:  Ortho Rh1 D Typing Reagents for Patients

Zeyd Merenkov, MD, FCAP, FASCP

Independent Consultant in Transfusion Medicine and Blood Bank IT

Revision Date:  21/3/18

Principle:

We must select D-negative RBC units for transfusion if the patient is truly D-negative or if he/she is a partial D since transfusion of a partial D positive unit may induce antibodies against any part of the D molecule.  Thus, for patients, we will consider patients with partial D as D-negative.  Note that this is NOT the usual practice in the USA;  however, AABB Standards do allow that we do NOT test patients for weak D and give D-negative RBCs instead.

Background:

Ortho Diagnostics Reagents use two different monoclonal antibody cocktails that react variably with the antigen D (Rh1)—these are found on the card:  Anti-A/B/A,B/D/D/Ctrl:

Anti-D/Anti-RH1—IgM monoclonal antibody clone D7B8 can detect most examples of weak and partial D including weak D types 1, 2, 3, 4.0, and D categories II, III, IV, V, VII, DBT, and R0Har.  It does NOT detect category VI.  Retest positive reactions of 2+ or less by an alternate method.

Anti-D/Anti-RH1—IgM monoclonal antibody RUM1 can detect most examples of weak and partial D including weak D types 1, 2, 3, 4.0, and D categories II, III, IV, V, VII, DBT, and R0Har.  It does NOT detect category VI.  Retest positive reactions of 2+ or less by an alternate method.

Policy:

  1. Follow the manufacturer’s instruction for storage, handling, and usage of all reagents.
  2. If the D-control is positive, the reactions are indeterminate, repeat by another method.
  3. Run both anti-D reagents listed—do not use the donor typing algorithm or reagents.
  4. Use the following table for interpretation and further actions if needed:
Pattern #Anti-D/D7B8Anti-D RUM1D-Interpretation
1PositivePositiveD-positive
2PositiveNegativeDo additional testing
3NegativePositiveDo additional testing
4NegativeNegativeD-negative  

If the reaction is 2+ or less with either the Ortho anti-D/D7B8 reagent or anti-D/RUM1 or if the patterns 2 or 3 above, repeat by another manufacturer’s reagents.  In the meantime, consider the patient as D-negative.

Medinfo-Ortho interface settings for Patient Testing in Hematos Medinfo IIG:

Anti-D/D7B8Anti-D RUM1D-Interpretation
3, 43, 4D-positive
3, 40~
03, 4~
00D-negative
~~~

Note all of the following:

  1. If the result is D-indeterminate, use D-negative RBCs.
  2. No reagents may be able to detect all D variants.
  3. ~ means any other value for that reagent (1+, 2+, mf, hemolyzed)
  4. Note that this new algorithm makes a 2+ reactivity as indeterminate with Anti-D/D7B8 or Anti-D/RUM1.

References:

  1. Publication e631300291, Product Insert, Anti-A/B/A,B/D/CDE/Control Card, 2010, Ortho Clinical Diagnostics, High Wycombe, Buckinghamshire/UK
  2. Standards for Blood Banks and Transfusion Services, Current Edition, AABB, Bethesda, MD, USA