Major Crossmatch versus Type&Screen : Why to choose for Type&Screen

1. Major Crossmatch versus Type&Screen : Why to choose for Type&Screen Major Vandenvelde Christian, Physician – Biologist, Head of Military Service for Blood Transfusion, Head of Brugmann U.H.C. / Queen Fabiola Children U.H.C. / C.T.R. / Heysel R.C. Immuno - Haematology Laboratory

2. What is a Major Crossmatch ? • Compatible RBC Bag(s) request → • Patient RBC ABO-D(-CcEe)(-K) Typing → • Typing-compatible RBC Bag(s) selection → • Bag(s) RBC crossmatching with Patient plasma → • Bag(s) RBC compatible with Patient plasma → RBC Bag(s) reservation for Patient • What if positive Major Crossmatch ?

3. What is a Type&Screen ? • Compatible RBC Bag(s) request → • Patient RBC ABO-D(-CcEe)(-K) Typing + Patient plasma Screening for Irregular anti-RBC Ab by “crossmatching” with commercially available selected 3-RBC-panel(s) → • Patient plasma negative IAT → Typing-compatible RBC Bag(s) selection when needed • What if positive IAT ?

4. What if positive MXM / IAT ? • Positive MXM → • Either : further Bag(s) RBC Crossmatching with Patient plasma • Or : Patient plasma Screening for Irregular anti-RBC Ab → … • Positive IAT → • Irregular anti-RBC Ab Identification with commercially available 11-RBC-panel(s) → Typing- & Identification-compatible RBC Bag(s) selection when needed • What if available Bag(s) RBC were not phenotyped for concerned Ag ? • What if Patient anti-RBC Ab remain(s) unidentified ?

5. What if unidentified Patient Ab / non-phenotyped Bag(s) RBC Ag ? • Available Typing-compatible Bags RBC Crossmatching with Patient plasma • Available Typing-compatible Bags RBC phenotyping for concerned Ag • Typing- / Identification-compatible RBC Bag(s) searching by B.T.C. in : • national BTI RBC Bags stocks • international BTI Frozen-Phenotyped-RBC Bags stocks

6. PRELIMINARY CONCLUSION • Most of the time the right question will be : “Why to choose either for MXM or for T&S as FIRST RBC compatibility test ?” • 4 Ways to go : • MXM only → Example : Q.A.M.H. Blood Bank • T&S only → Example : Military Ops Support • First T&S, then MXM → Example : Brugmann U.H.C. (Laeken + Schaerbeek + Jette sites) / Queen Fabiola Children U.H.C. / Centre for Traumatology & Rehabilitation / Heysel Rehabilitation Centre Blood Bank • First MXM, then T&S → Example(s) : cfr previous presentation

7. Type&Screen resources constraints • Reagents : commercially available Screening RBC-panels are expensive but → • Technologists : Screening procedures are easy to automate but → • Equipments : Screening automates are expensive but → • RBC Bags stock : Screening allows • an average RBC Bags stock reduction of +/- 33% • an average RBC Bags expiry rate reduction of +/- 95%, especially when a M.S.B.O.S. has been successfully implemented, but →

8. Type&Screen Patient risks • Screening misses 1 allo-Ab per 3000 RBC compatibility tests but → • Screening misses 1 weakly-reactive potentially clinically significant allo-Ab per 30000 RBC compatibility tests but → • Screening-missed allo-Ab likely would not result in life-threatening reactions but → • Screening misses clerical ABO-compatibility RBC Bags selection / labelling errors but → • Screening is mandatory followed by an ABO-compatibility check but → • Screening misses allo-Ab present in residual plasma of RBC Bags but → • National BTIs have to warrant the absence of clinically significant allo-Ab in produced L.B.C.

9. MXM only : Burn Unit Q.A.M.H. Blood Bank support • Reagents & Equipments : • no de novo allo-Ab in 13 years • 3 allo-Ab at admission in 13 years • +/- 66% of requested RBC Bags are transfused • Technologists : • no experience in allo-Ab identification • 1 MXM for 2 RBC Bags from same apheresis donor • presence required for other lab tasks • RBC Bags stock : 2 times the average number of transfused RBC Bags • Patients risks : ABO-D-CcEe-Kk-compatible RBC Bags are electronically selected

10. T&S only : Military Ops Q.A.M.H. Blood Bank support • Reagents, Technologists & Equipments : • Screening before departure makes field-lab compatibility testing useless • Screening-positive soldiers remain in Belgium (0.01%) • RBC Bags stock : 20 refrigerated + 1200 frozen O Rh/K-negative RBC Bags are continuously available • Patients risks : • O Rh/K-negative RBC Bags are “universal” • RBC Bags are systematically tested for auto- & allo-Ab • Donor Typing occurs at least 2 times before first donation

11. First T&S, then MXM : Brugmann Blood Bank resources constraints • Reagents : unusually high frequency of allo-immunised, polytransfused & multipregnancy patients • Technologists : • important experience in allo-Ab identification • 4 years ago, 15% of requested RBC Bags were transfused • Equipments : 4 years ago, unusually high frequency of RBC Bags requests • RBC Bags stock : after 4 years, RBC Bags needs & expiry rates have already been reduced by 33% & 85%, respectively

12. First T&S, then MXM : Brugmann Blood Bank risks management • Extended phenotyping of haematology / oncology patients at first admission • As extended as possible electronic-crossmatch for haematology / oncology / childbearing patients • Maximal use of ABO-D-CcEe-Kk-DAT-IAT screened RBC Bags • Maximal availability of extendedly phenotyped RBC Bags • ABO-compatibility check at patient’s bed

13. FINAL CONCLUSION • QUESTION : “Why to choose either for Major Crossmatch or for Type & Screen as (FIRST) RBC compatibility test ?” • ANSWER : “It only depends on hospital blood bank human and material resources and patients risks management capabilities”