Thomas Pich (Leipzig/ DE), Dr. Malvina Bourgeois (Leipzig/ DE), Dr. Raymund Buhmann (Leipzig/ DE), Natalia Thriemer (Leipzig/ DE), Dr. Sven Starke (Leipzig/ DE), PD Dr. Jörn-Sven Kühl (Leipzig/ DE), Uwe Platzbecker (Leipzig/ DE), Prof. Dr. Reinhard Henschler (Leipzig/ DE), Georg-Nikolaus Franke (Leipzig/ DE)
Background
Stem cell transplantation is a quality-controlled key element in treatment of hematological disorders. Characterization of stem cell products follows internationally standardized criteria and is supervised by accreditation standards. We aimed to characterize the quality of all allogenic stem cell products obtained in our collection center produced within a 5-year period, and investigate stem cell function by engraftment criteria in two subcohorts of related donors transplanted in our hospital.
Methods
A total of 193 G-CSF mobilized peripheral blood (PBSC) and 74 bone marrow (BMSC) products collected 2018-2022 were analyzed for a total of 27 parameters including volume, CD34+ and T cell content. Graft function was analyzed in a cohort of adult patients with malignancies receiving PBSC (n=24) and pediatric mainly nonmalignant patients receiving BMSC (n=12). Successful engraftment was defined as neutrophil (NEU, >0.5 G/l), platelet (PLT > 50 G/l) and complete donor chimerism (>90%) determined by STR analysis and absence of overt relapse. Median follow-up for patients in the subcohort of related transplantations was 321 days.
Results
Unrelated PBSC contained a median of 7.9 x106 (range: 3.2–28.9) and related PBSC a median of 7.5 (range: 3.4–22.1) x106 CD34+/kg. Unrelated BMSC contained median 3.3 (range: 1–22.2) and related BMSC median 5.7 (range: 1.6–20.7) x106 CD34+/kg. In the related cohorts, median transplanted cell doses were 8.2 PBSC x106 CD34+/kg (3.4–22.1) and 7.0 x106 BMSC CD34+/kg (1.58–12.32). Median time to NEU recovery in days was 17 (10–23; PBSC) and 22 (14–28; BMSC) and to PLT recovery 15 (12–37; PBSC) and 22 (15–37; BMSC). Complete donor chimerism was reached in 20/24 of PBSC and 12/12 of BMSC patients. In the PBSC group, 1 patient died before engraftment and 1 rejected the graft. In BMSC, high graft volumes were difficult to apply in most children.
Conclusion
Guideline-conform in vitro product quality was reached throughout. Engraftment analysis indicated a slightly slower NEU and PLT engraftment in the BMSC compared with PBSC cohort. All but 2 PBSC patients reached engraftment. Grade 3 and 4 GvHD was so far observed in 1 PBSC and 1 BMSC transplant recipient. Pediatric BMSC could be optimized by volume reduction. Our analysis demonstrates that conform in vitro transplant quality is associated with robust stem cell regenerative function in our center.
Offenlegung Interessenkonflikt:
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