Case Scenario: Who, How, What and when not to : of desensitization.
Case Study: 20 year old boy (Amit) going for his third transplant, first transplant 2011 with father, second 2/20 unrelated, nephrectomy of second transplant 6/22 for graft intolerance. Has single antigen bead positive for multiple anti- HLA antibodies from 2019 and in 5/2022. He has multiple potential donors
| Sensitization History | 2 transplant and 10 blood transfusions | |||||
| HLA Typing | A | B | C | DR | DQ | DP |
| 1st Donor (B+) | 01, 01 | 49, 81 | 03, 11 | 02,03 | ||
| Father | ||||||
| 2nd txp donor (unrelated) | 02, 30 | 7, 42 | 03, 11 | 02, 06 | ||
| Father’s sister potential donor | 01, 36 | 53, 81 | 11,11 | |||
| Maternal Cousin | 30, 36 | 45, 53 | 04, 16 | 03, 15 | 04, 06 | |
| Emotionally related donor | 30, 68 | 42, 58 | 16, 17 | 03, 13 | 03, 04 | |
| Recipient (B+) | 01, 23 | 08, 81 | 04, 11 | 03, — | ||
| XM | T cells | B Cells | ||||
| CDC XM | Not Done | Not Done | ||||
| Flow XM | Not Done | Not Done | ||||
| Single Antigen Bead 2019 SAB Report – Click to View & 2022 SAB Report – Click to View |
Class I : Multiple anti HLA Abs | Class II: Multiple Anti HLA Abs. | ||||
Questions & Answers
Q1. Is the SAB from 2019 of any use currently or should we only rely on the 2022 SAB report?
Ans: Historic DSA are also of importance as they provide evidence of sensitization and likelihood of memory B cells, which may get activated post transplant and lead to Acute or chronic AMR in the long run, though may not cause hyperacute rejection. Hence we should evaluate with both historic and current SAB reports.
Q2. Which donor would you want to proceed with?
Ans: Unrelated potential donor would be immunologically best as no current antibodies and least historic antibodies. However legal and external committee requirements would be needed.
Q3.Any additional concerns that you have related to the immunological risk from the selected donor?
Ans: The unrelated potential donor is 3/6 match with the 2nd transplant donor and so concern is that post nephrectomy her antibody levels against that donor may increase and then there may be cross-reactivity to the new donor as well. Hence a repeat SAB should be done now.
Q4. What risks would you discuss with patient, donor and family?
Ans: Risk for AMR and need for desensitization will need to be discussed, should also consider other donors and preferably 2 haploidentical sibling, if present.
Q5. What would your desensitization plan be for this transplant?
Ans: ATG extra, increase tac, mmf and prednisone with higher maintenance.
