Month: Dec 2020

Framework for Establishing the Use of Universal Low-Titer Group A Plasma

drzeyd

This post outlines a framework for establishing the use of low-titer group A plasma as a universal donor.  Manual titering large number of donor specimens in my organization is not practical.  Using an automated system will also increase the precision of the results.

Process:

  1. Select a cut-off anti-B titer.  This should be determined by the blood bank medical director.
    1. I selected saline 1:64 based on recent THOR (Thrombosis Hemostasis Oxygenation Research) meetings
  2. Perform a survey of the anti-B titers in your blood donor population.
    1. At my sites, about 50% had titers less than or equal to 1:64.
    2. Determine how stable the titer is:
      1. For serial donor plasmapheresis, how long could you accept the donor as low-titer?
      2. Does the titer change between whole blood donations?
  3. Determine the target inventory level for universal plasma (group AB and low-titer A) based on current/past usage.
  4. Assess availability of automated immunohematology analyzers for titration.
    1. Titration may take up to 30 minutes per sample, during which time the machine cannot be used for any other purpose.
  5. Add a new blood type AU (for group A universal) for plasma in your blood typing algorithm.
    1. AU should be used interchangeably with group AB.
  6. Software:
    1. Set up new truth table in your blood bank computer system.
    2. Validate the modification in your blood bank donor and patient modules.
    3. Update ISBT code for this new product, verify your transfusion service module can read this.

Special notes:

  1. At my last location, we had only 3 analyzers capable of doing the titration.  Thus, we could only do 6 titrations per hour at the expense of stopping all other testing.  You will have to coordinate the titration with your other immunohematology testing.  Also, verify if all these equipment interface to your production software.  In my system, any test (including titration) could be performed at any location and its results be used for production purposes.
  2. Donor ABO antibody titers may fluctuate.  I would not use previous results to qualify a donor to be AU.  I would repeat the anti-B titer each donor encounter.  If I collect donor plasmapheresis, I would determine for how long the titer can be used (see 2.2.1 above).

References:

  1. Technical Manual, Current Edition, Bethesda, MD, USA
  2. Standards for Blood Banks and Transfusion Services Current Edition, AABB, Bethesda, MD, USA
  3. Medinfo Hematos IIG Donor Production Module

Platelet Depletion Apheresis Form

drzeyd

This is the apheresis form used for reductive thrombapheresis developed by my apheresis team and me. In particular, I want to thank Dr. Saloua Al Hmissi, Consultant Transfusion Medicine, and Ms. Mini Paul, Head Apheresis Nurse, all their hard work.

The attached form can be developed into a computer entry form if one has a suitable hospital information system. It is organized so that the apheresis nurse can quickly enter the data on one screen. Never forget that our goal is treat the patient–not spend all of our time on data entry!!

20/12/20

Data Entry Verification: Updated Version

drzeyd

This is an update from the previous version posted to include low-titer group A FFP/FP24 and low ABO-titer group O whole blood.

Principle:

This policy outlines steps taken to minimize the risk of data entry errors and is based on a dualistic approach:  review of results by a senior technologist and/or supervisor and various computer safeguards built into the Medinfo Hematos IIG blood bank computer HIIG system.  This policy also discusses the verification (here called authorization) and purge processes of HIIG.

Policy:

  1. Review by senior technical, supervisory, or transfusion medical staff:
    1. Designated test procedures require review by a second technologist before authorization.
    2. Complex immunohematology testing and specimens showing aberrant results (e.g. ABO/D discrepancies) are reviewed by the supervisors or designates and ultimately a transfusion medicine physician before authorization.
  2. Computer system HIIG rules:
    1. Privileges:
      1. System restricts which staff can perform specific tests
    2. Patient/donor identity:
      1. System asks end-users to verify patient/donor identity before starting any access to the patient/donor record.
      2. System performs historical database checking and flags any inconsistencies (e.g. historical ABO/D typing differences, etc.)
    3. Testing:
      1. Only selected staff have privileges to authorize or purge.
      2. ABO/D testing algorithms require entry of reactions, not interpretation of results and are compared to a truth table.
        1. Aberrant results require special review before ABO/D typing results can be authorized/purged.
        2. D-controls must be negative to allow D typing results to be authorized for liquid D-typing reagents.
      3. DAT results require appropriate controls to meet truth-table criteria.
      4. Eluates require last wash to be negative before authorization
    4. Blood components:
      1. Selection of RBC or plasma units requires two independent sample determinations within 72 hours of each other.
      2. ABO-incompatible RBC or FFP/FP24 transfusions are not allowed.
      3. Titer-based ABO blood group selection:
        1. Low titer group A FFP may be used as universal plasma like group AB.
        2. Group O whole blood with low anti-A and anti-B titers may be used for all ABO types.
        3. Acceptable titer threshold is specifically defined as parameters in Medinfo.
      4. Donors with any detectable clinically significant antibodies are permanently deferred.
      5. Depending on the patient’s antibody history, release of RBC units may require antigen-matched units.  Examples:
        1. Mandatory matching (only antigen negative matched units allowed—no antigen positive or antigen-untyped units):  Antibodies against H, D, c, K, k, Kpa, Kpb, Jsa, Jsb, Jka, Jkb antigens, anti-PP1Pk
        2. Priority matching (incompatible or untested can be approved by a transfusion medicine physician):  C,E, e, Fya, Fyb, M, S, s
        3. Antigen matching not required:  Lea, Leb, N
      6. Least-incompatible crossmatch require special authorization to release
      7. Protocols to force irradiation or other modified components can be setup in HIIG.
    5. Donors:
      1. Donor tests have same criteria as the same test used in patient testing for controls, etc.
      2. Donor demographics are read directly from the Ministry of Interior database—no manual entry (bar code only used).

References:

  1. Workflows for Hematos IIG (1001 through 1005), 2013-2020
  2. Standards for Blood Banks and Transfusion Services, Current Edition, AABB, Bethesda, MD, USA
  3. Guidelines to the Preparation, Use, and Quality Assurance of Blood Components, European Committee (Partial Agreement) on Blood Transfusion (CD-P-TS), Current Edition

Sample Stem Cell Collection Apheresis Form

drzeyd

This is a sample of the stem cell therapeutic apheresis form that my apheresis team and I developed. It can be readily made into an electronic form. I want to thank Dr. Saloua Al Hmissi, Apheresis Consultant, and Ms. Mini Paul, Head Apheresis Nurse, for their efforts in making this form a success.

Preventing Graft vs. Host Hemolytic Anemia

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Principle:

Donor lymphocytes in an organ transplant may make antibodies and cause a clinically significant hemolytic anemia, i.e. a graft vs. host hemolytic anemia GVHHA.  Optimal handling in these cases should include antibody screening/identification for all potential donors and recipients.  The transfusion medicine physician should review the results for possible issues of antibody/antigen incompatibilities to proactively select matched blood components and avoid GVHHA.

In the Medinfo blood bank computer system, we can make custom rules to ensure release of only antigen-matched units as needed.

Policy:

  1. Perform antibody screen and identification (if indicated) for all prospective organ donors and recipients.
  2. If the organ donor has clinically significant antibodies, check if the recipient has the corresponding antigens.  If so, select RBC units negative for the donor antibody specificities. 

Example:  Donor has anti-Kell (K1) and patient is K1-positive.  Use only K1-negative RBCs post-transplant.

  • Send the case to the transfusion medicine physician to review.  He will contact the clinicians as indicated.
  • Create a rule in Medinfo forcing the antigen matching.

References:

  1. Technical Manual, Current Edition, Bethesda, MD, USA
  2. Standards for Blood Banks and Transfusion Services Current Edition, AABB, Bethesda, MD, USA

Patient D-Typing Algorithm Using Ortho Monoclonal Cocktail Reagents

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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:

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

Information to Collect Before Contacting the Transfusion Medicine Physician

drzeyd

The Transfusion Medicine Physician needs certain minimal information to make a medical/clinical assessment and decide what action needs to be taken.

Policy:

  1. Before contacting the transfusion medicine physician, please obtain the following:
    1. Clinical diagnosis
    2. Transfusion history
    3. Medication history
  2. In the case of transfusion reactions, follow Interim Policy Transfusion Reaction Workup and be certain to include the following information before contacting:
    1. Vital signs (BP, pulse, temperature, respiratory rate) both pre- and post-transfusion
    2. Clinical symptoms (e.g. rash, urticaria, fever, respiratory distress, etc.)
    3. Pre-transfusion DAT if post-transfusion DAT is positive.
    4. Donor Unit DAT and eluate on the post-transfusion specimen if the post-transfusion DAT is positive and pre-transfusion negative.
    5. Eluate on the post-transfusion specimen if both the pre- and post-transfusion DAT are positive.

6/11/20

Rh Immune Globulin Candidacy Triage

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Principle:

All D-negative women without immune anti-D must be screened for the need to receive Rh immune globulin as soon as possible after birth.  If the mother is determined to be a candidate, then her specimen must either be screened for a large fetomaternal hemorrhage (FMH—e.g. by the E-rosette or similar technique) or directly quantitated for FMH by either the Kleihauer-Betke or flow cytometry.  The whole process must be completed so that the mother receives the entire dose of RhIG within 72 hours after delivery.

Pregnant women should have an ABO/D typing early in the pregnancy and an antenatal dose between 26-32 weeks.  Thus, at the time of birth, passive anti-D may be detected.  It is essential to know the history of RhIG administration.  In the following example, RhIG is dispensed by the Pharmacy.  If the RhIG is released by the blood bank, records should be easily obtained.

This procedure covers the hospital blood bank processes.  Close coordination between Transfusion Medicine and the obstetricians is essential for a successful Rh immunoprophylaxis program.

Abbreviations:

RhIG:  Rh immune globulin

FMH:  Fetomaternal hemorrhage

All plasma derivatives, including RhIG, are dispensed from Pharmacy.  It is the responsibility of the blood bank technologist to check the Pharmacy records for the history of RhIG administration.

For immunoprophylaxis after accidental Rh(D)-incompatible RBC transfusions, see the separate interim policy by that name.

Policy Details:

  1. Mothers with active (immune) anti-D are excluded from this procedure.  They do NOT need RhIG and to give them it is a waste of a valuable resource.
    1. If the D-negative patient has other RBC antibodies but no anti-D, then she remains a candidate for RhIG prophylaxis.
    2. RhIG has no effect for preventing alloimmunization to other RBC antigens.
  2. D-negative mothers with first-trimester abortions should be given at least 50 mcg IM RhIG dose.
    1. If clinically a large fetomaternal hemorrhage is suspected, then screen/quantitate for fetomaternal hemorrhage as detailed below.
  3. If the D-negative mother undergoes amniocentesis, version, or has had abdominal trauma, the obstetrician may request RhIG or if he suspects significant hemorrhage, fetomaternal hemorrhage quantitation and calculation of the RhIG dose as indicated below.
  4. Platelet transfusions from Rh(D) positive donors:
    1. Platelets derived from a Rh(D)-positive donor prepared by the buffy coat method or by apheresis, either suspended in plasma or PAS do not require RhIG administration.
    2. If a D-negative mother receives legacy, platelet-rich-plasma-derived platelets from a D-positive donor, it is at the discretion of the clinician to request one 300 mcg vial IM RhIG as potential immunoprophylaxis.  (Note:  PRP platelets are no longer prepared at HMC.)
  5. The cord blood of all infants from D-negative mothers without immune anti-D must be typed immediately for the D antigen upon receipt in the Blood Bank.
  6. If the D-negative mother received antenatal RhIG or if it is unclear if the anti-D detected in her blood is passive (i.e. antenatal) or active (immune), she must still be screened by this procedure.
  7. If the baby is D-negative, no further processing is necessary:  it is not necessary to give RhIG.
  8. If the baby is D-positive or if its D type is unknown, a maternal sample (EDTA-anticoagulated blood) must be screened for FMH (e.g. by the E-rosette technique).  This is done in Hematology Laboratory.
    1. The E-rosette test will detect a minimum of 10 ml of fetal RBCs.
  9. If the screen is not available, then direct FMH quantitation must be done (e.g. by either the Kleihauer-Betke staining or flow cytometry).  This is done in Hematology Laboratory.
  10. If the FMH screen is negative, then the mother should receive one 300 mcg. standard vial of IM-RhIG.
  11. If the FMH screen is positive, the dosage of RhIG must be determined by the amount of fetal bleed (expressed as “ml of fetal bleed”.)
  12. All FMH quantitation results must be calculated by a transfusion medicine physician or by the clinical service physician responsible for patient’s care and the dose of RhIG must be calculated as follows:
    1. Verify the type of RhIG available in Pharmacy:
      1. Type: IV or IM
      2. Dosage:  240/300 mcg and manufacturer’s suggested protection level:
        1. Each 240 mcg IM usually protects against 12 ml fetal bleed
        2. Each 300 mcg IM usually protects against 15 ml fetal bleed
        3. Note:  dosage depends on the origin of the pharmaceutical material.
    1. Calculate the number of vials as follows:
      1. Blood Volume in ml = (Weight in kg) X 70 ml/kg
      2. RBC Volume in ml = (Blood Volume in ml) X Hematocrit
      3. Fetal Bleed in ml = (%Fetal Bleed) X (RBC volume in ml)
      4. # Vials 300 mcg IM RhIG preparation = (Fetal Bleed in ml)/15
      5. # Vials RhIG 240 mcg IM = (Fetal Bleed in ml)/12
      6. Note:  some would add 1 additional vial to this calculation.
  13. If the calculation is performed by the Transfusion Medicine Physician, he should append a comment to the postpartum antibody screen ABID result of the mother using Medinfo Hematos IIG.
    1. If the calculation is performed by a designated individual outside Transfusion Medicine, he should document it in the patient’s medical record.
  14. The appropriate RhIG dose should be administered within 72 hours of delivery whenever possible.
    1. If greater than 72 hours post-delivery, still administer the dosage; however, the efficacy at preventing Rh(D) alloimmunization may be reduced.

Note:

  1. RhIG will only protect against forming anti-D antibodies, not any other clinically significant antibodies.
  2. If the patient is D-negative but has other clinically significant antibodies, still administer the RhIG as per the protocol above.

References:

  1. Technical Manual, Current Edition, Bethesda, MD, USA
  2. Standards for Blood Banks and Transfusion Services Current Edition, AABB, Bethesda, MD, USA

Opinion: Understanding Each Step of the Process

drzeyd

During an AABB inspection many years ago, I observed the Lead Assessor interacting with a medical technologist at the bench.  As expected, the Assessor asked in detail about the test and where the documentation and any teaching aids were located.  Most importantly, the tech was asked to explain the procedure step-by-step and if they knew WHY each step was done and how the various outcomes affected the test.

In my opinion, the WHY is the most important issue.  In our testing and processing, we are not baking a cake.  We do not need a mindless automaton to perform the steps without knowing what they are doing.  To get it right, the technologist must understand why he/she does each and everything—and what are the consequences for not following the procedure precisely.  If the staff member knows this, he/she has respect for the process and is more likely to adhere to the proper method.

In my interactions with my staff, I want to engage them in the importance of their testing to the patient’s care.  If they know that the result may affect the care, they may become more respectful of their work since they are part of the patient care team.

I want them to understand what each of the various results will mean to the patient, i.e. how he will be handled.  I give them updates about the patient’s condition.  A caring technologist is more likely to follow the steps properly.  They understand that a deviation from the process may adversely affect the patient.

To this day, I often go to the technologists and quiz them about what they are doing, e.g. why do they add a particular reagent, why the incubation time is 15 minutes versus 60 minutes.  I encourage them to check and recheck what they are doing if they have any doubts.  Working the bench is not a quiz or examination.  If they are uncertain, I want them to seek out the information, ask questions.  In fact, I tell them there is no shame in saying, “I don’t know”—but be certain to add, “I will find out what to do.”

Blood bank can be fatal to those who guess.  Each of us must know our individual limitations and seek the necessary knowledge.  In fact, many of my assessments are open-book.  They can use any resource in the blood bank or references on-line.  This is real life:  I discourage them from relying on memory if they are understand.  Our end point is the correct action.

13/12/20

Pre- and Post-Exposure Antiretroviral HIV Prophylaxis

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Principle:

Use of anti-retroviral therapy as prophylaxis for pre- or post-exposure (PrP or PEP) HIV prophylaxis may lower the viral load below detectable levels.

Policy:

  1. Defer any donor taking PrP or PEP anti-retroviral ART medications for three (3) months since the last dose.
  2. Donors taking ART drugs as treatment for HIV infection are still indefinitely deferred.
  3. Donor information pamphlets should be updated to include this new deferral.

References:

  1. AABB Association Bulletin #4, The Impact on Blood Safety of Effective Antiretroviral Medications for HIV Prevention and Treatment, 5/5/20
  2. DHQ Medical Deferral List, Version 2.1, AABB, Bethesda, MD, USA, June 2020