Histocompatibility Evaluations for HSCT at JHMI M. Sue Leffell, PhD Professor of Medicine Laboratory Director
JHMI Patient Population Adults Peds NMDP data >20,000 HSCT
JHMI HSCT Protocols Bone marrow (BMT) Mobilized peripheral blood (MPB) Double Cord Blood Units One haplotype matched* Donor Lymphocyte infusion (DLI)* * Non-myeloablative ( mini ) conditioning
Why Non-myeloablative? Permits transplantation of older patients Full marrow ablation is not tolerated well by adults due to other medical problems May be used for pre-transplant conditioning for bone marrow or mobilized peripheral blood transplants Also used for alternate protocols One haplotype matched Donor lymphocyte infusion
Myeloablative and Non-myeloablative HSCT Myeloablative: Intensive chemotherapy and irradiation Engraftment of HSCT is critical for patient survival Immunosuppression for GVHD. Non-myeloablative: Reduced chemotherapy, low dose irradiation Pre-Tx treatment necessary for engraftment Post-Tx immunosuppression controls rejection and GVHD.
JHMI Mini - Haplotype Matched Protocol Conditioning Regimen Dose level 2
Why Partial, One Haplotype Matches? Graft versus Leukemia (GVL) Effect Weiden, et al., N Engl J Med 304:1529, 1981 Patients with some GVHD have lower incidence of disease relapse One-haplotype donors selected to maximize GVL in mini haplotype and DLI protocols
Mobilized Peripheral Blood MPB) and Donor Lymphocyte Infusion (DLI) CD34+ stem cells mobilized in donor ± T cell depletion Variable periods of mixed chimerism Post-Transplant donor leukocyte infusions may be necessary for full donor chimerism Shlomchik WD. Nat Rev. 2007;7:340-352
Adult HLA Matching Requirements BMT or MPB related or unrelated donor Allele level match at HLA-A,B,Cw, DRB1, DQB1 (10/10) Mini Haplotype Donors selected to minimize HLA mismatch in hostversus-graft (HVG) direction; haplotype mm for GVL Donor lymphocyte infusion Donor must be mismatched for 2 or 3 alleles (A,B, DRB1) Preference for DRB1 mismatch in GVH direction
Pediatric HSCT Protocols: Matching Requirements Bone marrow HLA identical sibling preferred Fully matched unrelated donor 1 or 2 allele mismatch, related donor 1 or 2 allele mismatch, unrelated donor Mobilized peripheral blood Same as for bone marrow Double Cord blood Minimally matched at 4/6 antigens (A,B, DRB1) Must share at least 1 DRB1, allele ( full match preferred) Same criteria for adults (to 55 yo)
The image cannot be displayed. Your computer may not have enough memory to open the image, or the image may have been corrupted. Restart your computer, and then open the file again. If the red x still appears, you may have to delete the image and then insert it again. The image cannot be displayed. Your computer may not have enough memory to open the image, or the image may have been corrupted. Restart your computer, and then open the file again. If the red x still appears, you may have to delete the image and then insert it again. Kids are tough! They can tolerate full bone marrow ablation and partial HLA mismatches!
Histocompatibility Assessment HLA Typing Related donors :HLA ID vs. 1 haplotype Unrelated: NMDP Requirements for CT Antibody Screening and Crossmatching All unrelated donors All mismatched D:R pairs KIR typing primarily for research
Histocompatibility Assessment: HLA Typing Considers level of resolution needed Related donors Low resolution may be sufficient if genotyping possible High resolution needed for two siblings - for possible recombinant haplotypes Unrelated: NMDP Requirements for CT High resolution: HLA-A,B,C,DRB1, DQB1 Once selected all D:R pairs typed for HLA- A,B,Cw, DRB1, DQB1, DPB1 alleles
Typing Methods Low-Intermediate resolution Reverse SSOP/Luminex platform (One Lambda, Inc). Local serologic typing trays for back-up and confirmation of expression. High resolution Sequence based typing (SBT) Atria Genetics HLA-B and DRB1 kits Local HLA-A, Cw and DQB1 reagents
Typing Ambiguities!!! As of 07/11/08: HLA class I alleles 2215 HLA class II alleles 986
Ambiguity Resolution Integration of data from other test methods. SSOP hybridization patterns Genotyping data when available Additional testing with different amplicons and/or probes. Extension of sequence tested, eg. portions of introns or exon 4 for class I Allele separation with group specific primers, followed by sequencing of amplicons Cloning or other separation methods for hemizygous typing
Typing Protocol: HLA-Identical Siblings Pt + Family Members Limited family (genotyping not possible) Allele level typing of HLA-A, B,Cw, DRB1; DQ allele group level, unless higher resolution needed Sufficient family for genotyping Low resolution typing class I (A,B,Cw) Potential HLA-ID sibs Typing for class II (DR,DQ) 2 or more HLA-ID donors HLA-DP typing Possible Recombinants (parent homozygous at 1+ loci) - Allele level typing
HLA Typing: Unrelated Donors Patients: Allele level - HLA-A,B,C, DRB1 Allele groups DQB1 (unless needed as tie breaker) Donors: Allele level - HLA-A,B,C, DRB1 Allele groups DQB1 (unless needed as tie breaker) HLA-DP typing: Decision among multiple donors Risk factor for GVHD 1 MM increased GVL benefit 1 1 Shaw BE, et al., Clinical Importance of HLA-DPB1 in HSCT, 2007. Tissue Antigens; 69 (S1):36-41
Pending NMDP Confirmatory Typing Requirements Must perform high resolution typing for common, well documented alleles (CWD)* Do not have to resolve CWD alleles that have identical sequences in antigen recognition site Must test for 3 common null alleles A*2409N exon 4 B*5111N exon 4 Cw*0409N exon 7 * Cano P,et al. Common and well documented alleles: Report of the ad-hoc committee of the ASHI. Human Immunol 2007; 68:392-417.
Strategy to Resolve Cw*040101/0409N Ambiguity Requires full length (3416bp) amplicon 5 UTR through 3 UTR Previous Cw typing only exons 2,3 sequenced; Cw*0409N requires exon 7 Amplicon length requires different DNA polymerase: GeneAmp High Fidelity enzyme mix (Applied Biosystems) Designed 12 sequencing primer mixes for exons 1,2,3,4,5,6,7 To reduce cost, single direction sequencing for exons 1(reverse), 4-7 (forward); bidirectional for exons 2,3.
Locus and Group Specific Amplification Loci Exons Seq Direction Supplier A 2,3,4 Bi-directional Local A2 2,3 Single Direction Local B 2,3,4 Bi-directional Commercial B-TA 2,3 Single Direction Local Cw 2,3 Bi-directional Local 1,4,5,6,7 Single Direction
HLA- Haplo ID Donors Pt and Potential Donors Low Resolution Typing Class I Class I Haplo ID Donors Low resolution Typing class II Donor Selection Best match to minimize rejection Pt and Donor Allele level typing HLA-A,B,Cw,DRB1 Allele group typing DQB1, DPB1
Antibody Testing: HSCT and Transfusion Support Hemapheresis/Transfusion Support Quick Screen run weekly Emergent samples, as needed AB identification on all + samples HSCT Candidates Screened monthly until TX Donors screened once selected AB identification on all + samples
Crossmatches: HSCT Timing Preliminary with donor evaluation Final within one week of TX Types and Methods Forward and reverse Autologous Virtual Xms in some cases
Antibody Testing: Methods Screening Pooled antigen/luminex platform (Tepnel, Inc) Pooled and single phenotypes/microarray chip (Invitrogen, Inc.) CDC panel (40-60 cells) Measure of AB titer Detection of IgM and auto-abs Antibody Identification Class I, II phenotype panels/ Luminex (Tepnel) Single antigen beads/ Luminex (One Lambda, Inc)
Risk of Graft Failure with a Positive Crossmatch 13/21 31/501 0/6 Mickelson, et al. Clin Transplants 2002.
Humoral Sensitization: Haplo ID Donors AB screens Pt and donor AB screen+ AB ID for DSA Pre-TX CDC Crossmatch (XM) XM+ and/or DSA + XM - and DSA - Evaluate other donors or Alternate treatment Post TX AB monitoring Suggested intervals: 1-2 months, or for suspected engraftment failure
Humoral Sensitization: Unrelated Donors Patient and Potential Donor Screened for HLA specific Antibodies (HLA-A,B,Cw,DR,DQ, DP) Pre TX CDC XM DP Antibody+ 1 1 80% or more of D:R pairs matched for 10/10 alleles (A,B,Cw,DRB1,DQB1) will likely be mismatched for at least 1 DP allele. Shaw, et al. 2007 5082 D:R pairs 54% mm for 1 allele 32% mm for 2 alleles
Humoral Sensitization: HLA-ID Sib Pairs Patient and Potential Donor Screened for HLA specific Antibodies (HLA-A,B, Cw, DR, DQ, DP) CDC XM for Highly sensitized Pts DP mm +, DP Antibody+ These options may be useful as decision factor if more than 1 donor is possible.
The Best Outcome!!