Marcelo Pando UNOS Region 5 Collaborative March, 2017 Histocompatibility Evaluation for Sensitized Patients: Maximizing the Patient’s Benefit. Marcelo Pando UNOS Region 5 Collaborative March, 2017
Disclosure Relevant Financial Relationship None Off Label Usage
Learning Objectives Understand the complexity of the HLA system. Discuss some of the methodologies we use to detect antibodies against HLA. Understand the current HLA practice in solid organ transplantation. Discuss some educational cases.
The Human Leukocyte Antigen In Medicine: In Nature: Organ Transplantation Ag presentation DIVERSITY! Disease association Pregnancy HLA Interaction with KIR Drug hypersensitivity Mate selection!
Then… HLA in Transplantation.
The First Crossmatch
Crossmatch by complement-dependent cytotoxicity (CDC): Donor cells + CFDA Patient serum Complement EtBr carboxy- fluorescein diacetate
Crossmatch by Complement-Dependent Cytotoxicity (CDC): NEGATIVE POSITIVE
The HLA System: Antigens and alleles HLA-A Serology: A2 Molecular: A*02:01 Alleles of A2: A*02:01, A*02:02, A*02:03, A*02:04…… A*02:336 carboxy- fluorescein diacetate
HLA Epitopes AA Pos. 10 20 30 40 50 60 70 80 90 100 A*01:01:01:01 GSHSMRYFFT SVSRPGRGEP RFIAVGYVDD TQFVRFDSDA ASQKMEPRAP WIEQEGPEYW DQETRNMKAH SQTDRANLGT LRGYYNQSED GSHTIQIMYG A*02:01:01:01 ---------- ---------- ---------- ---------- ---R------ ---------- -G---KV--- ---H-VD--- ---------A ----V-R--- AA Pos. 110 120 130 140 150 160 170 180 190 200 A*01:01:01:01 CDVGPDGRFL RGYRQDAYDG KDYIALNEDL RSWTAADMAA QITKRKWEAV HAAEQRRVYL EGRCVDGLRR YLENGKETLQ RTDPPKTHMT HHPISDHEAT A*02:01:01:01 ----S-W--- ---H-Y---- ------K--- ---------- -T--H----A -V---L-A-- --T--EW--- ---------- ---A------ --AV------ AA Pos. 210 220 230 240 250 260 270 280 290 300 A*01:01:01:01 LRCWALGFYP AEITLTWQRD GEDQTQDTEL VETRPAGDGT FQKWAAVVVP SGEEQRYTCH VQHEGLPKPL TLRWELSSQP TIPIVGIIAG LVLLGAVITG A*02:01:01:01 ------S--- ---------- ---------- ---------- ---------- --Q------- ---------- -----P---- ---------- ---F------ AA Pos. 310 320 330 340 A*01:01:01:01 AVVAAVMWRR KSSDRKGGSY TQAASSDSAQ GSDVSLTACK V A*02:01:01:01 ---------- ---------- S--------- ---------- - AA Pos 10 20 30 40 50 A*01 GSHSMRYFFT SVSRPGRGEP RFIAVGYVDD TQFVRFDSDA ASQKMEPRAP A*02 ---------- ---------- ---------- ---------- ---R------ AA Pos. 110 120 130 140 150 A*01 CDVGPDGRFL RGYRQDAYDG KDYIALNEDL RSWTAADMAA QITKRKWEAV A*02 ----S-W--- ---H-Y---- ------K--- ---------- -T--H----A AA Pos. 210 220 230 240 250 A*01 LRCWALGFYP AEITLTWQRD GEDQTQDTEL VETRPAGDGT FQKWAAVVVP A*02 ------S--- ---------- ---------- ---------- ---------- AA Pos. 310 320 330 340 A*01 AVVAAVMWRR KSSDRKGGSY TQAASSDSAQ GSDVSLTACK V A*02 ---------- ---------- S--------- ---------- - 1 2 3 4 6 5 β1 α1 α2 β2 Epitopes are defined by the differences of the self antigen and the immunogenic antigen.
HLA Epitopes: The Bw4/Bw6 Case AA Pos. 10 20 30 40 50 60 70 80 90 100 B*07:02:01 GSHSMRYFYT SVSRPGRGEP RFISVGYVDD TQFVRFDSDA ASPREEPRAP WIEQEGPEYW DRNTQIYKAQ AQTDRESLRN LRGYYNQSEA GSHTLQSMYG B*13:01:01 ---------- AM-------- ---T------ ---------- T---MA---- ---------- --E---S-TN T--Y--N--T ALR------- ---II-R--- B*13:02:01 ---------- AM-------- ---T------ ---------- T---MA---- ---------- --E---S-TN T--Y--N--T ALR------- ----W-T--- B*15:13:01 ---------- AM-------- ---A------ ---------- ----MA---- ---------- ------S-TN T--Y--N--I ALR------- ---II-R--- B*15:16:01 ---F------ AM-------- ---A------ ---------- ----MA---- ---------- --E-RNM--S ---Y--N--I ALR------- ----W-R--- B*44:02:01:01 ---------- AM-------- ---T------ -L-------- T---K----- ---------- --E---S-TN T--Y--N--T ALR------- ---II-R--- B*14:01:01 ---------- ---------- ---------- ---------- ---------- ---------- ------C-TN T--------- ---------- ------W--- B*14:02:01 ---------- A--------- ---------- ---------- ---------- ---------- ------C-TN T--------- ---------- ------W--- B*15:01:01:01 ---------- AM-------- ---A------ ---------- ----MA---- ---------- --E---S-TN T--Y------ ---------- ------R--- B*15:02:01 ---------- AM-------- ---A------ ---------- ----MA---- ---------- ------S-TN T--Y------ ---------- ---II-R--- B*15:03:01 ---------- AM-------- ---------- ---------- ---------- ---------- --E---S-TN T--Y------ ---------- ------R--- B*15:10:01 ---------- AM-------- ---------- ---------- ---------- ---------- ------C-TN T--Y------ ---------- ------R--- B*15:11:01 ---------- AM-------- ---A------ ---------- ----MA---- ---------- --------TN T--Y------ ---------- ------R--- B*15:11:02 *--------- AM-------- ---A------ ---------- ----MA---- ---------- --------TN T--Y------ ---------- ------R--- B*15:11:03 *--------- AM-------- ---A------ ---------- ----MA---- ---------- --------TN T--Y------ ---------- ------R---
The Dogma of AMR Assumptions: Antibody to the Donor Antibody Mediated Rejection Assumptions: Antibody is specific to the donor The test detects clinical relevant antibodies There is enough antibody to trigger IR
The Dogma of AMR DSA AMR
Tests for Antibody Screening
Luminex: Two different targets PRA Beads Phenotype: A2, A3; B7, B44; Cw4, Cw7 Less sensitive More stable SAB SA: A2 High sensitivity Less stable = denature Ags = False Positives
SAB
Phenotype Beads (PRA Beads) AECI294 AECI294
Calculated Panel of Reactive Antibodies (cPRA) the percentage of donors that will be excluded probability of having a positive crossmatch likelihood of getting an incompatible organ 100-cPRA = probability of getting a compatible organ
Examples of cPRA Patient with 20% cPRA 20% of donors will be excluded 20% of crossmatches will be positive 80% probability of getting a compatible organ
Maximizing Successful Offers The CPRA game Likelihood of Compatible Donor
Allele Specific Antibody DRB3*02 Single Antigen Beads o con un unico antigeno de HLA
CPRA Single Antigen Beads o con un unico antigeno de HLA
Single Antigen Bead (SAB) test results: Single Antigen Beads o con un unico antigeno de HLA
Case 1: 100% cPRA patient
Case 2: 100% cPRA patient
Unacceptable antigens Case 1: A1 A2 A3 A11 A23 A24 A25 A26 A29 A36 A34 A43 A66 A68 A69 A80 B13 B27 B2708 B44 B58 B60 B61 B7 B73 B76 B8 B81 B57 DR4 DQ7 DQ8 DQ9 Case 2: A1 A3 A11 A2403 A25 A26 A29 A30 A32 A33 A34 A36 A43 A66 A68 A69 A74 A80 B7 B8 B13 B27 B2708 B42 B45 B49 B50 B56 B57 B58 B62 B63 B67 B71 B72 B73 B75 B76 B77 B81 Cw1 Cw5 Cw6 Cw7 Cw8 Cw12 Cw14 Cw16 Cw17 Cw18 DR1 DR4 DR7 DR8 DR10 DR103 DR11 DRB1*13:03 DRB1*14:02 DR15 DR16 DRw51 DRw52 DQB1*06:03 DQ2 DQ5 DQ7 DQA1*04:01 DPB1*01:01 DPB1*04:01 DPB1*05:01 DPB1*19:01
cPRA Case 1: A1 A2 A3 A11 A23 A24 A25 A26 A29 A36 A34 A43 A66 A68 A69 A80 B13 B27 B2708 B44 B58 B60 B61 B7 B73 B76 B8 B81 B57 DR4 DQ7 DQ8 DQ9 Case 2: A1 A3 A11 A2403 A25 A26 A29 A30 A32 A33 A34 A36 A43 A66 A68 A69 A74 A80 B7 B8 B13 B27 B2708 B42 B45 B49 B50 B56 B57 B58 B62 B63 B67 B71 B72 B73 B75 B76 B77 B81 Cw1 Cw5 Cw6 Cw7 Cw8 Cw12 Cw14 Cw16 Cw17 Cw18 DR1 DR4 DR7 DR8 DR10 DR103 DR11 DRB1*13:03 DRB1*14:02 DR15 DR16 DRw51 DRw52 DQB1*06:03 DQ2 DQ5 DQ7 DQA1*04:01 DPB1*01:01 DPB1*04:01 DPB1*05:01 DPB1*19:01 100% 99.5069% 100% 99.9971%
Probability of 1: 203 donors cPRA Case 1: Case 2: 100% 99.5069% Probability of 1: 203 donors 100% 99.9971% Probability of 1: 34,483 donors
Maximizing Successful Offers Unacceptable Ags A2: 48% CPRA
Summary An accurate definition of a antibody profile can give more opportunities to waiting list patients. Determining the list of HLA antigens to avoid is patient specific and depends on several factors. Highly sensitized patients, particularly the 100% cPRA, needs especial assessment to maximize their opportunities. These patients, although a minority in the waiting list, have enormous differences in the opportunity of getting a compatible organ.
Thanks!