1. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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”