Specific features of red cell blood types in migrant populations: How to resolve this challenge in Europe?

Transcription

1 Thierry PEYRARD PharmD, PhD, EurClinChem French National Institute of Blood Transfusion (INTS) - Paris National Immunohematology Reference Laboratory (CNRGS) Specific features of red cell blood types in migrant populations: How to resolve this challenge in Europe?

2 I declare no conflict of interest related to this presentation

3 PRESENTATION OVERVIEW French experience with regard to the management of migrant patients, especially those of African descent Rare blood challenge, especially for SCD patients Case studies European perspective

4 ETHNIC POPULATION BACKGROUND IN FRANCE France: 66 million inhabitants Ethnically mixed population o o o Migrant people from the former French colonies of Africa (1 st or 2 nd generation) Overseas territories Recent population movements through Southern Europe

5 POPULATION BACKGROUND Former French colonies of Africa p, P k Ge:-2,3, Lan- Jk(a-b-), At(a-) RH:-46 (R N R N ) Fy(a-b-) RH:-18 (Hr S -) RH:-34 (Hr B -) RH:-57 (cejal/cejal) RH:-58 (cecf/cecf) RH:-59 (ceag/ceag) RH:-61 (cemo/cemo) Js(b-) At(a-) S-s-U-/U+ var Dantu

6 POPULATION BACKGROUND U-/U+ var, Js(b-) Hr S -, Hr B - Jk(a-b-) D r y r y U-/U+ var U-/U+ var, Bombay, Dantu, Hr S -, Hr B -, RH:-61 (cemo/cemo) Jk(a-b-) French overseas territories

7 MAJOR TRANSFUSION ISSUES IN FRANCE Patients of African descent with a rare blood type and who need chronic transfusion => sickle cell disease patients Fetus, newborn and their mother of African descent, alloimmunized to a high-prevalence antigen Emergence of new challenges due to recent population movements

8 SICKLE CELL DISEASE IN FRANCE Sickle cell disease (SCD) is the most frequent genetic disease in France ( 15,000 patients, number expected to double by the next 15 years) Patients often transfused and at high risk of developing RBC alloantibodies => systematic match for Rh (C,E,c,e) and K for over 30 years (1985) Many rare blood types in people of African descent (Rh, MNS, Kell, Dombrock, etc.)

9 WHICH TESTS DO WE PERFORM FOR SCD PATIENTS?

10 SEROLOGICAL TESTING Most Africans are D+C-E-c+e+, Fy(a-b-), Jk(a+b-), S-s+ (if Fy(b-) excluded, compatible blood is present in less than 0.3% of Europeans) Some antigens are very rare in Europeans but frequent in Africans (e.g. V, VS, D W, DAK, Js a, He, etc.) Low prevalence V/VS Js a D W DAK He Europeans "Balanced" prevalence Fy a : 66%* High prevalence U

11 SEROLOGICAL TESTING Some antigens are very rare in Europeans but frequent in Africans (e.g. V, VS, D W, DAK, Js a, He, etc.) Low prevalence Africans "Balanced" prevalence D W Fy a DAK He Js a V VS 5% 10% 20% 40% U High prevalence

12 SEROLOGICAL TESTING If RBC units are transfused in an intra-ethnic background, higher risk of developing anti-vs, anti-js a, anti-d W, etc., which are not detectable by routine antibody screening panels! => Panels sold in Europe are poorly appropriate for patients of African descent. Different approach in Asia (inclusion of Mi(a+) RBCs) and Brazil (inclusion of Di(a+) RBCs)

13 SEROLOGICAL TESTING Systematic serological crossmatch mandatory in France for SCD patients, whatever the background (age, gender, immunization status) Systematic search for anti-v/vs, anti- Js a, anti-d W in all SCD patients investigated in our reference laboratory Match for V/VS and Js a status for all rare units delivered to SCD patients, whenever possible

14 RH VARIANTS IN PEOPLE OF AFRICAN DESCENT Significant prevalence of Rh antigen variants of clinical relevance In our experience (SCD patients) 10% of D+ are partial D 35% of C+ are partial C! 3-5% of e+ are partial e 2% of c+ are partial c Usually not screened by standard typing reagents

15 RH VARIANTS IN AFRICANS Essential to distinguish common RHD/RHCE variants and those with proven clinical significance (publications) In France, for example: - DAU-0 is not considered partial D - RHCE*ce733G and RHCE*ce48C,733G are common alleles not considered to be at risk: no proven alloanti-hr B to date, only autoanti-e after full serological workup. It is not because a genotype is claimed to encode an apparent hr B - type that alloimmunization to hr B is possible

16 GENOTYPING IN SCD PATIENTS New policy implemented in late 2016 (pilot phase): All SCD patients are subject to RHD and RHCE genotyping, except those with 12 transfusion episodes being nonalloimmunized (including at least one transfusion with D+ RBCs for R 0 R 0 patients) (considered low-responders ) => cost/efficiency approach (genotyping not reimbursed so far!) This threshold value of 12 RBC units is consistent with a work published by a Dutch team in August 2016

17 Rh/K matched

18 STANDARD DNA-CHIP PERFORMED IN ALL SCD PATIENTS REFERRED TO OUR LAB System Phenotype System Phenotype MNS U- DI Di(b-) U+ var SC Sc:-1 RH Hr B - LU Lu(b-) k- DO Hy- Jo(a-) KEL Kp(b-) CO Co(a-) Js(b-) LW LW(a-) 13 rare blood types simultaneoulsy screened in one single test (BeadChip HEA v1.2 BioArray/Immucor)

19 Two other DNA chips: RHD and RHCE RH*C cesl RH*E ceti RH*c cert RH*e cera RH*C w Ce-D(4)-Ce [R N ] RH*C x DHAR cear ceek cebi cemo [ce(667)] ce S [ce(733,1006] ce s [ce(733)] ce s (340) ce S (748) cecf r G CeMA CeVA CeVG E type I E type II (EKK) E type III E type IV EKH Example of the RHCE chip: 6 rare Rh blood types simultaneously screened in people of African descent Hr S - (RH:-18) Hr B - (RH:-34) R N R N (RH:-46) RH:-57 (RHCE*ceJAL/RHCE*ceJAL) RH:-58 (RHCE*ceCF/RHCE*ceCF) RH:-61 (RHCE*ceMO/RHCE*ceMO)

20 RH*C RH*E RH*c RH*e cesl ceti cert cera RH*C w Ce-D(4)-Ce [R N ] RH*C x cear ceek cebi (& cesm screening) cemo ce S ce s ce s (340) ce S (748) cecf DHAR r G CeMA CeVA CeVG E type I E type II (EKK) E type III E type IV EKH Two major limitations c.254c>g mutation (ceag) (RH:-59 if homozygous) and heterozygous R N variants are not screened => 2 additional tests - SSP-PCR for R N screening in all C+ patients - SSP-PCR for RHCE*ce254G screening RHCE*ceAG found at the heterozygous state in 20% (30/150) of a cohort of young SCD patients in France! => allele frequency = 10% (manuscript in preparation)

21 ONGOING STUDY Investigation of 150 children with SCD (0 to 18 yo) followed up in one single hospital (Paris area) and by the same medical team Systematic molecular testing 3 DNA chips (HEA, RHD, RHCE) SSP-PCR for RHCE*ceAG and R N in C+ patients RHD exon 8 sequencing, because the RHD chip is unable to detect all the DAU types, especially those out of DAU-0, considered to be partial 8% show a partial RHCE antigen, 13% a partial D! (Manuscript in preparation)

22 PATIENTS OF AFRICAN ORIGIN AND RARE BLOOD

23 ACTIVITY OF THE FRENCH NATIONAL RARE BLOOD BANK ~ 7,200 frozen RBC units (-80 C) from 1,800 donors 300 rare RBC units delivered per year (80 patients) 40% of rare RBC units transfused to sickle cell disease patients 5% of RBC units shipped abroad

24 ACTIVITY OVER THE LAST 3 YEARS 854 THAWED RARE RBC UNITS Peyrard T. Immunohematology 2016

25 46 UNITS SHIPPED ABROAD 2013/ /10 Most requests for patients of African ancestry

26 46 UNITS SHIPPED ABROAD 2013/ /10 A few examples in Europe Germany: 4 p, 3 Fy(a-b-), 2 Hr B -, 1 U- Switzerland: 4 P 1k, 3 U-, 2 Hy, 1 O h Belgium: 4 RH:-46 (R N R N ) Portugal: 1 U-

27 THE S-s- RARE BLOOD TYPE Mean prevalence in Africans is 1-2% but may reach up to 40% in equatorial Africa Highest gap between supply and demand in France! 8% of the requested rare units within the last 3 years Also becomes a major problem in several European countries

28 A FEW REMINDERS ON THE RARE S-s- BLOOD TYPE Several molecular backgrounds for the S-srare blood type encountered in Africans 50% are S-s-U- => deletion of the GYPB gene (delgypb/delgypb) 50% are S-s-U+ var => weak and partial U - P2 (90%) - NY (10%) All are able to develop anti-u, with the strongest examples found in S-s-U- S-s-U+ var RBCs are not compatible with anti-u made by S-s-U- patients

29 THE S-s- RARE BLOOD TYPE IN FRANCE 78 U- donors, all confirmed by genotyping => 237 frozen units 83 U+ var 76 P2 279 units 7 NY 17 units

30 ANTI-U ALLOIMMUNIZATION 340 patients with alloanti-u reported in France 70 SCD patients followed with anti-u Major difficulties when patients are U- and also: C-e- (R 1 R 1 ): 2 donors (A and O) O, D-: 9 donors e-: only 2 donors (A and B) SCD patients with anti-u is a huge problem for RBC exchange programs!

31 THE S-s CHALLENGE ~20% of our S-s- rare RBC units come every year from the Martinique Island, in the Caribbean sea

32 CASE STUDIES

33 CASE STUDY 1 SCD patient, scheduled to undergo a complex surgery with bleeding risk A, D+C-E-c+e+, K-, Fy(a-b-), Jk(b-), M-N+S+s- Antibodies: anti-c, anti-e, anti-jk b, anti-m, anti-s Only 4 compatible blood donors in France!

34 CASE STUDY 2 SCD patient with severe crisis and anemia O, D+C-E-c+e+, K-, Fy(a-b-), Jk(a-), S-s-U+ var Anti-D (partial D DAR), anti-jk a, anti-u Only 8% of Africans are Jk(a-) => one single compatible donor with 3 frozen units!

35 CASE STUDY 3 36 yo patient of African origin Group O, D+C+E-c-e+, K- This Rh phenotype is very uncommon in Africans => at risk of being a rare Rh blood type named RH:-46 or Sec- (R N R N )

36 High risk for R N R N (RH:-46) to be now overlooked with most column agglutination devices!

37 CASE STUDY 3 RH:-46 rare type confirmed by phenotyping and genotyping Extended phenotype performed Fy(a-b-), Jk(b-), M-N+S-s-! Genotyping to confirm if U- or U+ var

38 CASE STUDY 3 => Incidental finding of a rare Js(b-) type! => U- phenotype

39 This Fy(a-b-) patient shows three rare blood types! RH:-46 U- Js(b-) CASE STUDY 3 Probably the only one reported in the world! Not alloimmunized as of today

40 CASE STUDY 4 Blood samples referred from Belgium in August 2016 Anti-LU13!

41 CASE STUDY 4 Other rare blood specificities potentially found in refugees from the Middle Eastern countries: In(b-), Ge:-2, p, P 1k, O h, etc.

42 THE FUTURE Cultured RBCs? Cultured RBCs obtained from - CD34+ cells from apheresis - Human induced pluripotent stem cells (hipsc)

43 HUMAN INDUCED PLURIPOTENT STEM CELLS (hipscs) Fibroblast RBC Dedifferentiation Reprogramming Pluripotent stem cell

44 APPLICATION TO TRANFUSION OF SICKLE CELL DISEASE PATIENTS From 1996 to 2011, one single donor with group O, D-C-E-, K-, Fy(a-b-), Jk(b-), M-S-s- U-, V-, VS-, Js(a-), Do(a-) would have theoretically met 73% of the needs of SCD patients requiring blood from the National Rare Blood Bank (Peyrard T & al. Transf Med Rev 2011) One individual with such a phenotype was found in 2016 in the Paris area!

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46 COMMENTS/CONCLUSION Many specific features and constraints for the transfusion of patients of African origin IVD companies need to be more aware of this in Europe Inclusion of new antigens in antibody screening panels (VS, Js a, He ) Typing reagents able to screen the major Rh variants Optimization of genotyping devices («African DNA-chip»?)

47 COMMENTS/CONCLUSION Rare blood types in SCD patients, especially U-, represents a major challenge in many European countries International collaboration and active network for sharing of experience and rare blood supply is necessary Besides the International Rare Donor Panel (Bristol, UK), should not a European registry of rare donors be implemented? Ongoing project at the EDQM

48 COMMENTS/CONCLUSION No official European rare blood bank anymore (one used to exist in Amsterdam) Should we not consider this again? As used to be the case in Amsterdam, could this blood bank potentially be partly funded by the European Council? A critical mass of frozen RBC units in one or two locations would be necessary to better ensure rare blood supply (cost/efficiency approach and 24/7/365 activity)

49 HAPPY ETRUSCAN RETIREMENT! THANK YOU FOR YOUR ATTENTION!