Blood Bank Review. Case #1 ABO/Rh. Case #1 Antibody Screen. Is the ABO grouping discrepant? No Interpretation: O positive

Transcription

1 Blood Bank Review Mary Burroughs Blood Bank Technical Specialist Mercy Health Saint Mary s Case #1 ABO/Rh Forward Grouping Reverse Grouping Anti-A Anti-B Anti-D A1 cells B cells Is the ABO grouping discrepant? No Interpretation: O positive 2 Case #1 Antibody Screen Screening Cell AHG Reaction I 0 II 4+ Antibody Screen is Positive Next Step: Antibody Identification 3 1

2 Case #1 Antibody Identification Typically, perform antibody identification using same methodology as that used in antibody screen Perform auto control - Patient Cells with Patient Plasma Assess reactions - Perform cross-off procedure 4 Case #1 Cross-Off Procedure Identify non-reactive cells Cross off antigens present on the non-reactive cells - If blood group system exhibits dosage, only cross off based on homozygous donor (double dose antigen) - Dosage systems: Rh, Duffy, Kidd, MNS Continue cross off with all non-reactive cells - Don t forget to use non-reactive Screening Cell Case #1 Cross-off 2

3 Case #1 Crossed Off Case #1 Assess Results Identify any antigens not crossed off Ignore (for now) any low prevalence antigens not crossed off - V, C w, Kp a, Js a, Lu a Assess remaining antigens Case #1 Assess Results Does the pattern appear to match just one antibody? - Are there variation in strengths? Dosage? Multiple antibodies? - Is there extra reactivity? Most likely additional antibody 3

4 Case #1 Assess results Assess for satisfaction of Rule of Three - Three reactive cells where antigen is present - Three non-reactive cells where antigen is absent - If multiple antibodies satisfy the Rule of Three independently for each antibody - Gives 95% certainty that antibody identification is correct. Case #1 Further Work? Are all non-suspect antigens ruled out? - Yes Have we satisfied the Rule of Three? - Do we have 3 E+K- cells that reacted? No need one more - Do we have 3 E-K+ cells that reacted? No we need two more - Do we have 3 E-K- cells that failed to react? Yes Case #1 Further Work Find additional cells that will fit the phenotype needed Run cells using same methodology Reassess for expected reactivity 4

5 Case #1 Select/Run Additional Cells Case #1 Assess Additional Cells Case #1 Assess Additional Cells Did we achieve the expected reactions? - Yes Have we satisfied the Rule of Three - Yes 3 E+K- cells that are reactive 3 E-K+ cells that are reactive 3 E-K- cells that are non-reactive Are variations in reaction strength explainable? - Yes E+e- cells are reacting stronger than E+e+ anti-e is stronger than anti-k 5

6 Case #1 - Transfusion If this patient needs an RBC Transfusion - Must supply E-K- unit - Must perform serologic AHG crossmatch - If units are incompatible look for additional antibody (ies) Case #2 ABO/Rh Forward Grouping Reverse Grouping Anti-A Anti-B Anti-D A1 cells B cells Is the ABO grouping discrepant? Yes Interpretation:?? 17 Case #2 Saline Replacement Saline Replacement Technique - Spin reverse grouping tubes - Remove plasma with pipette - Replace removed plasma with 2 drops of saline - Shake out tubes - True agglutination will remain but rouleaux will disperse Reverse Grouping before Saline Replacement A1 cells B cells Reverse Grouping after Saline Replacement A1 cells B cells

7 Case #2 Antibody Screen Gel Card Causes for Mixed Field in Gel Patient Reacting to pre-diluted cells - Most common reason we see mixed field in gel in our lab - Resolve by diluting 3% cells to 0.8% and repeating in gel - BUT in this case we also have the ABO discrepancy Rouleaux - Already attempted saline replacement in ABO discrepancy without resolution Actual two cell population - Would not be seen in antibody screen since commercial cells are from non-transfused donors IgM antibodies - Start our investigation here. Case #2 Antibody Screen Screening Cell AHG Reaction I mf II 0 Antibody Screen is Invalid Next Step: Antibody Identification Alternate Method 21 7

8 Case #2 Original Panel LISS/Tube Case #2 Cross-Off Procedure Identify non-reactive cells in all 3 phases Cross off antigens present on the non-reactive cells - If blood group system exhibits dosage, only cross off based on homozygous donor (double dose antigen) - Dosage systems: Rh, Duffy, Kidd, MNS Continue cross off with all non-reactive cells Case #2 Assess Results Identify any antigens not crossed off Ignore (for now) any low prevalence antigens not crossed off - V, C w, Kp a, Js a, Lu a Assess remaining antigens 8

9 Case #2 Cross-Off Case #2 Assess Results Does the pattern appear to match just one antibody? - Are there variation in strengths? Yes Dosage? Yes Multiple antibodies? No evidence at this point - Is there extra reactivity? No Case #2 Further Work? Are all non-suspect antigens ruled out? - No - Need one M-S+s- - Need one M-Jk a -Jk b + Once we run these additional rule out cells, will we have satisfied our Rule of Three? - Three M+ cells that are reactive? Yes (cells 12, 13, 15, 17, 18, 20, 21) - Three M- cells that are non-reactive? Yes (cells 15, 19, 22) 9

10 Case #2 Select Additional Rule Out Cells Case #2 Select Cell Panel Results Case #2 Assess Additional Cells Did we achieve the expected reactions? - Yes Have we satisfied the Rule of Three - Yes 3 M+ cells that are reactive 3 M- cells that are non-reactive All additional common antigens have been ruled out Are variations in reaction strength explainable? - Yes M+N- cells are reacting stronger than M+N+ 10

11 Alternate Method for Rule Outs M-S+s- is a rare cell. What if not available? - Antigen Type the patient Cannot be transfused in past three months If antigen positive patient cannot make corresponding allo antibody Saves from having to rule out in the future Patient cannot have positive DAT if commercial antisera utilizes an AHG reaction. Cells are already coated with antibody and will give possible false positive reaction at AHG. What about our ABO Discrepancy? Commercial A1 and B cells are a pool of donors - Most likely several of those donors are M+ - Type commercial cells for M - Perform reverse grouping using known M- reverse grouping cells to resolve discrepancy Forward Grouping Reverse Grouping Anti-A Anti-B Anti-D M- A1 cells M- B cells Patient is A positive Case #2 - Transfusion If this patient needs an RBC Transfusion - Refer to institutional policy - Options: Supply AHG xm compatible, M- units Supply AHG xm compatible units Treat as non clinically significant and don t perform AHG crossmatch 11

12 Case #3 43yo Female with bowel obstruction Hgb 8.5 g/dl Scheduled for colectomy on 2/15/17 Case #3 ABO/Rh Forward Grouping Reverse Grouping Anti-A Anti-B Anti-D A1 cells B cells Is the ABO grouping discrepant? No Interpretation: B positive Case #3 Antibody Screen Screening Cell AHG Reaction I 0 II 4+ Antibody Screen is Positive Next Step: Antibody Identification 12

13 Case #3 Antibody Identification Case #3 Cross-Off Able to cross off all antigens except E and Kp a - Kp a is low incidence and we can ignore for now Have we met our Rule of Three for Anti-E? - 3 E+ cells that are reactive? - 3 E- cells that are non-reactive? - Yes we ve met the Rule of Three Crossmatch Units Even though only a type and screen was ordered: - Patient is going to surgery - Because of her antibody, patient is not eligible for abbreviated crossmatch procedure (IS or Electronic) and we can t supply blood quickly if patient needs it urgently - Crossmatch two E- units through AHG Patient does well in surgery and does not require transfusion 13

14 Six Days Later (2/21/17) Patient s hemoglobin has fallen to 6.8g/dl without obvious signs of bleeding Physician writes an order to transfuse one unit of leukoreduced, packed red blood cells Because we know she has an anti-e, we can run rule out cells instead of a whole panel if: - Antibody screen pattern matches that of the known antibody - Strength has not increased Case #3 Rule out Cells Case #3 Rule out Cell Reactions 14

15 Case #3 Full Panel Results Case #3 Cross-Off Case #3 Panel Assessment Other than the anti-e; what additional antibody appears to be present? - Kp a, Jk b, S, and Lu a remain after cross-off - Ignore low incidence for now: Kp a, Lu a - Looking at the E- cells, does the pattern fit Jk b or S perfectly? Yes perfect Jk b pattern showing dosage 15

16 Case #3 Additional Work Need to rule out anti-s with E-, Jk b -, S+s- cell Have we satisfied the Rule of Three? - We have 3 Jk b + cells that are reactive - We have 3 E-, Jk b - cells that are non-reactive - We only have 1 E+, Jk b - cell that is reactive Refer to institutional policy regarding previously identified antibodies What about the positive Auto Control? - Need to perform an elution and identify that antibody Case #3 Rule out S Elution Dissociate antibody from the cell for purposes of phenotyping the red cell - Acid/Glycine EDTA or Chloroquine Dissociate antibody from the cell leaving the antibody in usable form for identification - Heat or Freeze/Thaw used for ABO HDN investigations - Acid or organic solvents 16

17 Case #3 Eluate Results Case # 3 - Interpretation Anti-E and anti-jk b Anti- Jk b is also coating the patient cells - Where did this come from? Not present 6 days ago Patient had remained hospitalized and not received blood - Communication with patient revealed prior medical history in Florida and also a transfusion at a different hospital in Grand Rapids. Case #3 Medical History Investigation Called other Grand Rapids hospital - Positive antibody screen identified anti-e - Transfused two E- RBC on 2/14/17 (day before admission to our hospital) Called Florida hospital - Patient had been seen in previous years - Anti-E and anti-jk b identified!!!!!! 17

18 Case #3 - Conclusion Previous history of anti-e, anti-jk b Anti-Jk b had fallen to undetectable levels Both of the units given at neighboring GR hospital had been Jk b + Patient suffered Delayed Hemolytic Transfusion Reaction - Low grade fever - Hemoglobin fell from 8.5 g/dl to 6.8 g/dl in 7 days - Bilirubin rose from 0.5 mg/dl to 2.3 mg/dl - No pre LDH but post LDH was 430 IU/L Thank you for your attention today Good luck to the students taking the national certification exam Remember: Antibodies are what make blood banking fun! 18