1. HLA Department, Lab Complex
NRL for DNA diagnostics
Institute of Hematology and Blood Transfusion
MONITORING OF CELL CHIMERISM IN ADULT PATIENTS AFTER ALLOGENEIC HEMATOPOIETIC STEM CELL TRANSPLANTATION
Ing. Kristýna Pegová
11th East West Immunogenetics Conference, Olomouc

2. Introduction
Chimerism - coexistence of genetically different cells in one body
- arise after allogeneic hematopoietic stem cell transplantation
Clinical significance - monitoring of engraftment dynamics
- activity allogeneic hematopoiesis
- first signs of autologous repopulation
- early detection of relapse and disease recurrence

3. Chimerism testing in ÚHKT
Regularly investigation since 1992
From 1992 to 2016 – 1139 transplantations in 1083 patients
More than one transplantation underwent 49 patients
44 patients two transplantations
4 patients three transplantations
1 patient four transplantations

4. Conditioning and donors
Conditioning - 69% myeloablative
- 31% nonmyeloablative
Donors - 61% unrelated
- 39% related % haploidentical (annual increase)
The first
successfull

5. Diagnostics groups
The most frequent
82%

6. Methods Short tandem repeats (STR) – sensitivity 1%
Quantitative real-time PCR (qPCR) –
Median of complete chimerism achievement (only donor genotype)
– 28th day after alloHSCT
Median of engraftment (< 50% of recipient genotype)
– 14th day after alloHSCT
sensitivity 1%
high sensitivity (0,035%)

7. Results Level of cell chimerism corresponds to cell graft status
The survival probability depends on:
Diagnosis
Presence of autologous hematopoesis (MC vs. CC)
Relapse and disease recurrence

8. Survival curve - diagnosis
77%
40%
Transplantation date

9. Survival curve – recipient genotype presence
62%
29%
Transplantation date
Increase from CC to MC means in most cases relapse

10. Survival curve – relapse I
59%
31%
Transplantation date
Relapse occurred in 25% of patients
Median of relapse arise is 180 days after transplantation

11. Survival curve – relapse II
17%
Relapse date
50% of patients die within seven months from the relapse detection

12. Conclusion Using sufficiently sensitive method (as qPCR)
The ability to detect lower percentage of autologous haematopoiesis
Earlier detection of relapse and disease recurrence
Early potential therapeutic intervention (e.g. donor lymphocyte infusion - DLI)
Higher survival probability
Cell chimerism examination is the important marker for post-transplant monitoring

13. External proficiency testing
Organizing since 2005
Since 2014 on the list of EPT providers within European Federation for Immunogenetics (EFI)
Current offer – two variants
basic
extended
Recipient + donor
5 quantification samples/year
Recipient + donor
10 quantification samples/year
EFI standard – v6.3, point C6.4.7
Contact: Mgr. Hana Čechová, tel , 117,

14. Acknowledgement Sponsors: - Ing. Pavla Hrabáková - Mgr. Hana Čechová
- MUDr. Renáta Přerovská
- Mgr. Lucie Pavlátová
- RNDr. Monika Leontovyčová
- Dagmar Březinová
- Martina Staňková
Supported by the project Ministry of Health, Czech Republic for conceptual development of research
organization ( , UHKT)
Sponsors: