Case Scenario: Crossmatch Is Positive, What to do?
Case Study: 40 y/o Female with ESRD (Ankita) and on dialysis for 1 month with unknown etiology, with her husband as donor. Rest of her workup is normal. After you rule out her husband as donor, one of her 2 sons come forth as potential donor though Ankita does not want them to donate. Immunological workup is below.
| Sensitization History | 2 Pregnancies | |||||
| HLA Typing | A | B | C | DRB1 | DQB1 | DQA1 |
| Donor | 02:11, 24:07 | 08:01, 52:01 | 03:01, 10:01 | 02:01, 05:01 | 01:01, 01:01/04 | |
| Recipient | 11:01, 24:02 | 35:03, 51:01 | 04:04, 13:01 | 03:02, 06:03 | 01:03, 03:01 | |
| XM | T cells | B Cells | ||||
| CDC XM | Positive | Positive | ||||
| Flow XM | Positive | Positive | ||||
| Single Antigen Bead SAB Report 1 – Click to view |
Class I : Multiple anti HLA Abs | Class II: Multiple Anti HLA Abs. |
Questions & Answers
Q1. Which of the class II HLA antibodies are donor specific?
Ans: DRB1*03:01, DRB 10:01 negative. DQB1*02:01 is positive, DQB1*05:01 is negative.
Q2. What are these DRB3, DRB4, DRB5 Antibodies and how do we figure out if they are donor specific?
Ans: These are additional drop in antigens also called DR 51,52, 53 and can be assessed from linkage analysis, though not perfect, or additional typing.
Q3. Are HLA DP antibodies, important or can we ignore those antibodies? Do I really need to get HLA DP typing?
Ans: Yes, lots of DP antibodies in this recipient and hence will need DP typing prior to proceeding for transplant for this recipient.
Q4. Why does she have so many HLA antibodies, when her exposure is to only HLA from her husband?
Ans: HLA alleles and antigens have many common epitopes and as they are shared between them, reactivity to common epitopes can show up as broad anti-HLA sensitization.
Q5. How would you counsel the family and Who would be the best donor for her?
Ans: Reviewing her antibodies with her son, she has no antibodies against her elder son, it is likely that the younger son has the antigens from the husband that she has made antibodies against. Important to make haplotypes within families HLA to assess for family relationships and also to make it easier to assess for HLA incompatibility.
