Historically, the Lui-Freeze-Thaw elution method was used to detect ABO antibodies in suspected cases of ABO hemolytic disease of the fetus/newborn HDFN. However, the detection of such antibodies does not mean that they are clinically significant. If a clinically significant antibody is suspected, perform acid elution instead. If you want to detect ABO antibodies in a neonate or in a transplant setting, you can use this eluate against reagent A and B cells.
Policy:
For suspected cases of significant ABO antibodies (HDFN, organ transplant), perform acid-elution:
For ABO antibodies, test the eluate against reagent A and B cells using antiglobulin phase.
If the mother is ABO-incompatible with the neonate and the neonate’s DAT is positive with a negative eluate against panel cells, then test against A and B cells to rule out ABO antibodies
The same applies to organ transplant cases to detect ABO antibodies.
For detection of non-ABO antibodies, test the eluate against an antibody panel (i.e. group O cells).
References:
Technical Manual, Current Edition, AABB, Bethesda, MD, USA
Standards for Blood Banks and Transfusion Services, Current Edition, AABB, Bethesda, MD, USA
Guidelines to the Preparation, Use, and Quality Assurance of Blood Components, European Committee (Partial Agreement) on Blood Transfusion (CD-P-TS), Current Edition
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.
The following was my interim policy at HMC for permissible matching and mismatching. This assumes that the patient is not being transfused while in a hypothermic state.
The prohibited options were blocked in the Medinfo Hematos IIG computer system. WAIHA least-incompatible release required physician approval. This protocol did not apply to low-titer group A or low-ABO-titer whole blood units, which were not available at the time.
Physicians must enter their interpretations and recommendations for each transfusion reaction review. In addition, they may enter comments against any of the data. This post shows the process used in Medinfo Hematos IIG.
By highlighting Interpretation (left side), they then click on the Result Field (right side) and select their interpretation from the drop-down menu. They can also select other and then enter a comment.
References:
Standards for Blood Banks and Transfusion Services, Current Edition, AABB, Bethesda, MD, USA
Guidelines to the Preparation, Use, and Quality Assurance of Blood Components, European Committee (Partial Agreement) on Blood Transfusion (CD-P-TS), Current Edition
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:
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:
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.
Typing reagents such as anti-D, anti-K, anti-Fya, etc. must be checked each day of use.
Already defined explicitly in SOPs
Anti-IgG reactivity of antiglobulin reagents may be checked during antibody screening and crossmatching:
Currently performed as per manufacturer’s instructions (e.g., Immunocor, Biorad, Grifols, Ortho) for gel and tube reagents.
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:
Already defined explicitly in SOPs
References:
Standards for Blood Banks and Transfusion Services, Current Edition, AABB, Bethesda, MD, USA
Guidelines to the Preparation, Use, and Quality Assurance of Blood Components, European Committee (Partial Agreement) on Blood Transfusion (CD-P-TS), Current Edition
Maintaining an adequate blood supply and expedited compatibility testing are critical in disaster planning. Medinfo Hematos IIG allows us to get dynamic updates of our blood supply and dynamically reallocate blood components as needed.
Policy:
Determinate total available blood supply across all locations by using the Cumulative Stock Display program in Medinfo Hematos IIG.
Recheck stock at least every hour during the disaster.
At each transfusion service site, in conjunction with a Transfusion Medicine Consultant:
Cancel reservations for elective surgical and non-emergency medical cases of affected ABO/D types.
Retain reservations for antigen-matched, oncology, NICU, and high-risk obstetrical cases.
Inform Donor Recruitment/Logistics to send SMS, radio, and television messages for blood donors—all types.
Contact ALL staff and have them report to duty.
At the Blood Donor Center, the Head Nurse, Recruitment, Supervisor, Component Processing, and Supervisor, Marker Testing will contact staff.
At hospital transfusion services, the site supervisor will contact all staff.
Process blood components using automated component technology (Reveos).
Perform all donor marker testing including single-well NAT.
Abbreviation of donor marker testing is only at the discretion of the Division Head, Transfusion Medicine.
Transfusion Services:
Release blood component according to the various protocols as needed:
Massive Transfusion Protocols
Emergency release
STAT
Priority
Routine
Compatibility testing will be electronic, immediate-spin, or full AHG as per our protocols.
References:
Standards for Blood Banks and Transfusion Services, Current Edition, AABB, Bethesda, MD, USA
Guidelines to the Preparation, Use, and Quality Assurance of Blood Components, European Committee (Partial Agreement) on Blood Transfusion (CD-P-TS), Current Edition
Although we did extended Rh and Kell typing for all cases with a non-negative antibody screen, we did not routinely do this for patients with a negative antibody screen.
Principle:
Based on recent cases of rare phenotypes in the Rh system (e.g. r’r’), we will proactively test such patients most likely for this.
Policy:
Extended Rh (C, c, E, e) and Kell typing should be done on all patients meeting the any of the following criteria:
This is the sample examination I made for the senior-most staff and candidates. This is really a projective exercise. How far can you go with this? The candidate must specify what additional information he/she needs to complete the assessment.
Name: Badge #:
Date of Exam:
Answer the following questions:
What is the ABO blood type in each of the following results:
Anti-A
Anti-B
Anti-A,B
A1 cells
B cells
O Cells
ABS
Type?
0
4+
3+
0
0
0
0
3+
0
3+
1+
4+
0
Neg
3+
1+
3+
0
3+
0
Neg
Weak
0
2+
0
4+
0
Neg
0
0
0
4+
4+
4+
Pos, all cells
Weak
0
0
4+
4+
4+
Pos, all cells
0
4+
3+
4+
2+
0
Pos, SCIII
Mf
0
0
0
4+
0
Neg
ABS = antibody screen; mf = mixed field reaction
Assume that all reactions are the same by both the tube and gel methods.
In the above table, list any discrepancies in each of the testing panels. Describe what additional tests or information, if any, are required to resolve the type.
What is ABO and D typing in each of the following results?
Anti-A
Anti-B
Anti-D
D-control
A1 cells
B cells
O cells
ABS
4+
4+
4+
3+
4+
4+
4+
Pos All cells
Anti-A
Anti-B
Anti-D
D-control
A1 cells
B cells
O cells
ABS
0
0
4+
2+
4+
4+
0
0
Anti-A
Anti-B
Anti-D
D-control
A1 cells
B cells
O cells
ABS
0
0
4+
2+
4+
4+
2+
2+
Using anti-D antisera, explain the difference in reactivity you expect between R1R1 and R2R2 cells.
Describe at least two antibody specificities associated with a mixed field reaction.
Describe the discrepancy noted in the following gel reaction and provide a differential diagnosis for the possible cause(s).
Describe when to use Diluent 1 versus Diluent 2 with the Diamed gel cards.
There is a critical staffing shortage so you are working the bench when emergency, class I blood is released (O-positive to a 25 year old male victim of a car accident). You receive the specimen and obtain the following set of results:
Anti-A—0, Anti-B—0, A1 cells—4+, B cells—4+, ABS—3+ in SCI/II/III
What actions will you take now? What blood type will you release for subsequent RBC requests? Be explicit!
An extended phenotype is ordered and Diamed Profile I-II-III cards are used. The following results are obtained on Profile Card III:
M
N
S
S
Fya
Fyb
0
0
0
0
0
0
Interpret these results.
Describe the rationale for the prophylactic use of E-c- cells in a patient only showing anti-E.
A patient develops pain at the infusion site with back pain while a unit of packed RBCs is being transfused. The following results were obtained in the subsequent workup:
Pretransfusion ABO/D: B-positive—reverse typing normal
Post-transfusion ABO/D: B-positive—reverse typing normal
Returned unit ABO/D: B-positive
Repeat crossmatch—compatible
Give possible reasons for these findings. What further investigations would you do?
Interpret the following panels:
48 year old female with septic arthritis and severe anemia (Hgb 6.9 g/dl) and positive autocontrol 2+ (Polyspecific 2+, IgG 2+, C3d nil) and negative antibody screen:
The eluate panel results follow:
Please give your interpretation of the findings. Be sure to specify other information you may require if any.
71 year old female with aortic stenosis admitted for surgical correction, blood type AB positive, antibody screen 2+ positive in all 3 cells, autocontrol negative, no history of recent transfusions.
The use of irradiated components is to inactivate antigen-processing cells, which have been implicated in transfusion-associated graft versus host disease (TAGVHD). This condition is may be fatal and has been reported in a variety of clinical settings, both in immunocompromised and immunocompetent hosts.
Since we pathogen-inactivate platelet components, we are only irradiating RBC components. There is no need to irradiate any plasma components (e.g. FP24, thawed plasma, cryoprecipitate, or cryo-poor plasma.)
WARNING: Do not irradiate stem cell units!!
Policy:
Irradiation of packed RBCs will be given to the following patients:
All candidates for stem cell transplantation SCT or patients post-SCT
All severely immunosuppressed, excluding AIDS patients including:
Congenital immunodeficiency states
Intrauterine (i.e. fetal) transfusions
Premature (less than 1500 grams or 28 weeks gestation) infant transfusions
Neonatal Intensive Care Unit patients
All hematopoietic tumors, including
Hodgkin’s disease/lymphoma
Non-Hodgkin’s lymphomas
All acute leukemias
Myelodysplastic states
Myeloproliferative states
Histiocytosis X, Langerhans histiocytosis
Aplastic anemia
All recipients of directed donations of any type, i.e. apheresis or components prepared from whole blood
Recipients of HLA-selected platelets or platelets known to be HLA homozygous
Irradiation Specification:
Irradiate just prior to release if possible to minimize potassium leakage.
Target 2500 cGy (rads) of gamma irradiation to the mid-plane of the canister of a free-standing irradiator is used or to the central mid-plane of the irradiation field if a radiotherapy instrument is used
Using returned irradiated RBCs:
If an irradiated unit is returned and otherwise meets re-release criteria, it may be used for up to 28 days after the irradiation or the normal outdate limit, whichever is less.
For pediatric use (< 20 kg.), if the component was irradiated more than 24 hours previously, wash it prior to transfusion.
If you are uncertain whether to irradiate, ask the supervisor or the transfusion medicine physician.
References:
Standards for Blood Banks and Transfusion Services, Current Edition, American Association of Blood Banks, Bethesda, MD, USA.
Guidelines to the Preparation, Use, and Quality Assurance of Blood Components, European Committee (Partial Agreement) on Blood Transfusion (CD-P-TS), Current Edition
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.
