Month: Aug 2021

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

Processes and Software Building: Profile Cards 1-2-3 for Extended Antigen Typing

drzeyd

This is an update of a previous post.

In any case with nonspecific antibodies and for all new patients who will require chronic transfusions, I perform extended Rh (CcEe)/Kell and the three Diamed (now Biorad) profile cards.

It is very easy in Medinfo to write a process for any group of antigen typings as long as you know the manufacturer’s criteria for accepting results.  Some cards have controls, others do not.  In the latter case, the “control” is a negative reaction in the card or series of cards of the same type.

In Medinfo, one can also look for errors in using the card:  In Profile Card 3, i.e. the MNSsFyaFyb card, one must reject the card if no reactions in any well appear:  Did the technologist forget to add the cells or reagents?  Did he/she use the wrong diluent (i.e. bromelin enzyme) which would destroy the labile antigens?

One can set the acceptable range of reactivity, flag for mixed field, etc. and record these findings in the official record.  One can define which reactions you will accept an automatic reading of the card.  For the other readings, one can force a manual review and result entry.

Note that Profile Cards 1 and 2 both have an internal control whereas Profile Card 3 (enzyme-labile antigens) does not.

Here are the processes for all three profile cards:

Policy: Division Head Transfusion Medicine Role in Policy Making

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Principle:

The Division Head, Transfusion Medicine and Blood Banks, is responsible for all aspects of transfusion medicine at HMC for the State of Qatar.  The following policy documents some of those roles.

Policy:

  1. The Division Head, Transfusion Medicine HTM, serves as a member of the Corporate Transfusion Committee
  2. The HTM through the CTC establishes criteria for transfusion of blood components and passes these through the HMC corporate process for establishing official guidelines.
  3. The HTM reviews blood component requests, especially in times of shortage to triage in conjunction with the Medical Director and Chairperson, DPLM
  4. The HTM establishes transfusion practices through the interim policies, which are in turn used to prepare processes and procedures through corporate transfusion medicine.
  5. The HTM serves as Project Manager for the Medinfo Hematos IIG computer system and prepares policies, processes, and procedures for Transfusion Laboratory Information Systems.

References:

Standards for Blood Banks and Transfusion Services, Current Edition AABB, Bethesda, MD, USA

Policy: Extended Rh and Kell Phenotyping

drzeyd

Principle:

Based on recent cases of rare phenotypes in the Rh system, we will proactively detect such patients and donors most likely for this.

Policy:

Extended Rh (C, c, E, e) and Kell (K1) typing should be done on all donors and patients meeting the any of the following criteria:

  1. D-negative phenotype
  2. Patients with positive antibody screens

References:

Standards for Blood Banks and Transfusion Services, AABB, Current Edition, Bethesda, MD, USA