Tag: Donor Immunohematology

Donor ABO/D typing, antibody screening, antibody identification, ABO antibody titration

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

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

Enzyme Panel Details

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Principle:

Performing antibody panels using both enzyme (ficin, bromelin, and/or papain)-treated  and routine panel cells may be necessary to detect most clinically significant antibodies

Policy:

  1. Regular (LISS) panels are to be performed using AHG reagents whereas enzyme panels done by the gel technology must use the saline (NaCl)-enzyme card.
  2. Perform BOTH enzyme and routine panels in the following situations
    1. All patients with sickle cell anemia and thalassemia
    2. Antibody pattern of panreactivity with a negative autocontrol (see attached examples)
    3. Antibody workup that does not show a specific pattern with the regular panel alone
    4. Any case with a previous history of antibodies with a current negative antibody screen
    5. Any other case that you are directed to do so by the transfusion medicine consultant, supervisor, or senior technologist.
  3. Remember the reactivities of the following antibody specificities with enzyme-treated cells:
    1. Reactions may not be the same with papain vs ficin-treated cells!
    2. Enzyme-labile with both papain- and ficin-treated cells:  Fya, Fyb, M, N, Ge2, Yta, Rg, Ch, Pr, Tn, Mg, Mia, Cla, Jea, Nya, JMH, Inb
    3. Variable, enzyme-labile or weakened, some unchanged with both papain and ficin-treated cells:  S, s, U
    4. Variable reactions with papain (labile, weakened, unchanged, or increased) but usually increased or unchanged with ficin-treated cells:  Kell system (K, k, Kpa, Kpb)
    5. Reactions are increased or unchanged with both papain and ficin-treated cells:  Rh (D, C, c, E, e), Jka, Jkb, Lea, Leb, Lua, Lub, P1, H, most cold antibodies, autoantibodies, Tja (PP1Pk)

Example 1:

Antibody to High-Incidence/Prevalence or Public Antigen:

Reactions destroyed by enzyme (typical of anti-Ge2):

Example 2:

Antibody to high-incidence antigen, reactions unchanged or enhanced by enzyme—VERY DANGEROUS PATTERN:  Examples:  Anti-H, Anti-Tja (PP1Pk), anti-k (cellano), anti-U

Processes and Software Building 56: Multi-Site Patient and Donor Considerations

drzeyd

As our hospital network expanded, there were many patients who moved between locations.  They might first start in an emergency room and then be transferred to a specialty hospital.  These locations might be served from different hospital blood banks/transfusion services.  What happens if work is progress from one site when the new site receives the patient.  Must the previous workup be repeated or could it be used for transfusion at the next site?

For example, the ABO typing could be performed at one site and the antibody screen at a second site, and the antibody identification at still another site.  Could the results be used across the entire system?

I had multiple hospital blood banks and blood donor centers.  The general and specialty laboratories had multiple sites.  The hospital information system was set up so that the various tests could only be performed at specific designated sites.  This posed problems as patients were moved around or if some site(s) became inoperative since the specimens then had to transported at great distances for testing.  Only a few basic STAT tests were available at all sites.

It was my decision to allow all test categories at all sites, e.g. a DAT request from any site, any methodology, could be used to satisfy the order.  Similarly, all donor processes were available at all donor centers (the processes could be completed at one or more sites).  Different hospital blood banks had different equipment but all the test categories were the same across site—the methodologies might differ.  We had at least four different DATs across our system.

The interface between the blood bank and hospital system worked as follows:  In the hospital information system HIS, test orders pointed to a category of testing and any methodology for that category at any site could be used in the blood bank system for testing and reporting back to the HIS.  Any test in a category from any site could be used to satisfy the test request.  Blood bank staff would choose the particular test methodology to use.  It was NOT specified by the HIS!

In summary, for blood banks and donor centers within our system, the work could be flexibly moved between sites.  There was no need to repeat testing when a patient transferred to a new site.  The only type the work was repeated if testing was done at an institution outside our system.

Training Future Transfusion Medicine Physicians: Need for Technical-Medical Expertise

drzeyd

In a previous post, I discussed transfusion training for hematology fellows and general pathology residents.  I have no expectations that most of them have any interest in the field so I suggested concentrating on the interpretation of the direct antiglobulin test DAT and turn-around-times for services.

In contrast, the transfusion medicine physician in-training needs to understand in detail all processes, donor and patient—especially test interpretation so that he/she can make medical decisions and variances.

During my training, I was fortunate to be in a residency training program that also had an American Specialist-in-Blood Bank SBB training program.  To a large extent, I attended the SBB program and even worked on the “wet” specimens.

I had no delusions that I would ever function as technologist or SBB in the blood bank.  However, that extended blood bank training has made me the physician I am.  I can correlate advanced, even reference, procedures to my medical knowledge and thus provide a unique offering.  In contrast, even the SBB is not a physician and cannot make the medical correlations.  Recently, I was flattered at an AABB meeting when the speaker thought that I was an SBB.

In certain regions where reference immunohematology laboratories and SBBs or equivalent are rare, the transfusion medicine should have sufficient technical background to help fill this gap.  In my practice, I review all antibody and DAT workups and make interpretative comments for the physicians and nursing staff.  These comments are entered into the blood bank computer system.

I personally tutor the trainees and make certain that they understand potentially dangerous patterns such as antibodies to high-incidence antigens, significance of the autocontrol in panreactivity, and assessing for fatal acute transfusion reactions—both hemolytic and non-hemolytic.

It also helps when I can discuss with my technical staff my interpretations and choices for clinical management.  They get a better idea how important their work is for patient care and understand how any errors may adversely affect the patient.

In regions where there are good immunohematology reference laboratories, some of this may be less necessary.  I lament that transfusion medicine physicians may not maintain these skills and must rely on others to their detriment.  Even if one is comfortable with this, the physician is still ultimately responsible for making the clinical decision.

ABO Subgroup Testing for Organ Donors

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Principle:

Organ donors with a history of RBC transfusion within the past three months must have ABO subgroup (weak A as detected by A2 cells and anti-A1 lectin) if the transfusion included group A RBCs.

Policy:

  1. Organ donors who are typed as A should be tested to distinguish group A1 from weak subgroups of A.
  2. Use anti-A1 lectin and A2 cells as indicated.

Reference:

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

Clarification on Quality Control of Reagents for Antibody Screening and Identification

drzeyd

Principle:

This policy is a reiteration of current policy to QC reagents used for antibody screening and identification to document how current practice meets these requirements.  This policy is NOT a change from current practice.

Policy:

  1. Each cell used for antibody detection must be checked each day of use for reactivity of at least one antigen using antisera of 1+ or greater avidity:
    1. We will use reactivity encountered during the daily antibody testing:  reactions of 1+ in each screening cell will be deemed acceptable.  For panel cells, reactions of 1+ or greater for any specificity will be deemed acceptable.
  2. Typing reagents such as anti-D, anti-K, anti-Fya, etc. must be checked each day of use.
    1. Already defined explicitly in SOPs
  3. Anti-IgG reactivity of antiglobulin reagents may be checked during antibody screening and crossmatching:
    1. Currently performed as per manufacturer’s instructions (e.g., Immunocor, Biorad, Grifols, Ortho) for gel and tube reagents.
  4. Typing sera and reagent cells must be checked for reactivity and specificity on each day of use, including a check against known positive and negative cells or antisera:
    1. Already defined explicitly in SOPs

References:

  1. Standards for Blood Banks and Transfusion Services, Current Edition, AABB, Bethesda, MD, USA
  2. Guidelines to the Preparation, Use, and Quality Assurance of Blood Components, European Committee (Partial Agreement) on Blood Transfusion (CD-P-TS), Current Edition
  3. TRM.31400, CAP Checklist, current version

Donor Unit Discrepancies

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Principle:

All donor unit mislabeling is potentially life-threatening and must be stringently investigated as soon as possible after the discrepancy is detected.  Most importantly, if there is one error, there may be possibly ADDITIONAL donor unit errors (e.g. switch of donor tubes or units, etc.).  All donor units processed in the same batch must be also quarantined until the discrepancies are resolved.

The blood bank computer system will detect many errors;  however, if the donor unit or its samples are mislabeled in the beginning, these may not be detected.  Medinfo enforces checks on the final ISBT label and will compare current results to the historical record and will alert to any errors. Additionally, the use of ISBT specimen labels will obviate the risk of barcode reading errors.

Definitions:

Responsible blood bank physician:  specialist or consultant physician on-call at the time the discrepancy is detected

Policy Details:

The following steps MUST be performed as soon as possible:

  1. The Component Processing Supervisor or Senior Technologist must be IMMEDIATELY notified of any discrepancy.
  2. The Blood Bank Supervisor will inform the Division Head, Transfusion Medicine.  If the Head is not available, notify the Transfusion Medicine on-call.
  3. Quarantine ALL donor units collected and processed in the same batch.
  4. Obtain copies of all testing including photos of the gel/glass bead cards documenting the discrepancy.
  5. Obtain copies of all worksheets used in donor processing for the affected batch.
  6. Perform repeat ABO/D typing of ALL DONOR UNITS in the affected batch.  Any further discrepancies must be investigated and resolved.
  7. Identify all staff who were involved in handling the donor unit (phlebotomist, blood bank technicians processing and labelling the unit).  Identify those associated directly with the error.
  8. Submit all documents and photos to the Blood Bank Supervisor or designate.
  9. Prepare an occurrence/variance OVA report documenting all the data, findings, and interpretations.
  10. All investigations must be reviewed by the Supervisor, responsible blood bank physician, and one of the senior consultants.
  11. All such investigations must then be finally reviewed and approved by the Division Head, Transfusion Medicine or his designate.  Only when the issue(s) are completely resolved and investigation is approved may the donor unit be properly relabeled and released into available stock.  Also, only at that time may the other units in the affected batch be released into available stock!!
  12. Photograph the correctly relabeled unit and attach it to the other documentation of the incident.
  13. If the discrepancy cannot be resolved, ALL units in the affected batch must be discarded.
  14.  The implicated staff’s personnel record should be reviewed for previous errors.   Appropriate disciplinary action should be taken and documented in the personnel record.  If a verbal warning is given, it should still be documented in the written record.
  15. If there is a systemic cause for the error, appropriate measures should be taken to minimize reoccurrence.
  16. All actions must be in accordance with the institution’s policies and regulations.

2/11/20

Blood Bank Software is Dynamic, NOT Static

drzeyd

I was recently talking with one of the hospital software system administrators from my previous site.  He had originally worked on building the Medinfo system, but was then reassigned to the laboratory modules of the hospital information system.

His alarming comment to me was that the Medinfo build was completed so there was no need to worry about it now—it was finished.  I guess he was looking from the perspective of the general laboratory software.  There is no need to make major changes to the build, just update interfaces and troubleshoot.

I was surprised.  He had no idea of how many times we have to update the structure for new rules and regulations, and changes in blood bank practice—let alone emerging pathogens such as ZIKA, dengue, Chikungunya, and most recently, COVID-19.

My daily morning routine was to survey several blood bank websites with changes to blood donor criteria including US FDA CBER, read the transfusion journals (Transfusion, Vox Sanguis, etc.), AABB, and ASFA.  If there were any changes pertinent to our organization, I had to make interim policies and procedures, and finally prepare specifications for changes in the Medinfo software.

The Medinfo engineers would prepare flow charts of the proposed changes and implement them in a test environment for the Super-Users to test.  I had to prepare validation protocols for the testing, and then review the validation results and finally approve the adoption of the changes.

I cannot remember even a month going by without some revision in the donor protocols.  When COVID-19 came, I had to prepare a parallel, but separate, processing and allocation/release system.

This was a never-ending story that kept the Super Users and the local Medinfo engineers busy.  I always reminded the hospital information system staff that playing with blood bank software was like playing with fire:  there is a good chance you will get burned if you do not set it up properly.

31/10/20

Processes and Software Building 53: Donor Extended Rh and Kell Typing

drzeyd

For this typing, I always had both automated and manual methods set up on the blood bank computer system Medinfo Hematos IIG.  The automated method had a bidirectional interface between Medinfo and the instrument.   Medinfo did not need a separate middleware.  A truth table was prepared for acceptable results for automatic interpretation.  Other results had to be manually interpreted by someone with the appropriate security level.

It was standard in my donor processing laboratory that extended Rh typing (EeCc) and Kell were performed.  We were in a region with many sickle cell and thalassemia patients.  Having all RBC units pre-typed in the Blood Donor Center expedited selection and release in the hospital blood bank—especially for matching K-negative units to K-negative patients and extended Rh phenotypes for sickle cell patients.

The manual testing option is structured similarly.  Within Medinfo, it is easy to change the methodology or have more than one methodology if the system is so built.  Thus, if the analyzer for this typing was down, the staff could select the manual methodology.  Likewise, if one testing center went off-line, the work could be completed at another site—no need to repeat testing already completed from the first site.  This flexibility could apply to any test in system.

The manufacturer’s recommendations for the particular reagents in use were strictly followed.  Most importantly, Medinfo can be configured for any set of reagent values.

Please refer to the sample flowchart which also includes Cw and DVI+ typing.  The same process could apply to patient testing, but some reagents would use a DVI- reagent.

18/10/20