Related Experiment Video
Updated: Aug 30, 2026
Microbial Control and Monitoring Strategies for Cleanroom Environments and Cellular Therapies
Published on: March 17, 2023
Bacterial contamination of ex vivo processed PBPC products under clean room conditions
Markus Ritter1, Joachim Schwedler, Jörg Beyer
1Department of Haematology, Oncology and Immunology, Philipps-University Hospital, Marburg, Germany. markus.ritter@mailer.uni-marburg.de
Background:
Patients undergoing high-dose radio- and/or chemotherapy and autologous or allogeneic PBPC transplantation are at high risk for infections owing to profound immunosuppression. In this study, the rate of microbial contamination of ex vivo processed PBPC products was analyzed, comparing preparation under clean room conditions to standard laboratory conditions.
Study Design And Methods:
After implementation of good manufacturing practice conditions in the two participating institutions, the microbial contamination rate of 366 PBPC harvests from 198 patients was determined under certified clean room conditions (Group A) from 2000 until 2002. To investigate influence of improved environmental conditions along with other parameters, this set of samples was compared with a historical control set of 1413 PBPC products, which have been processed ex vivo under a clean bench in a regular laboratory room and were harvested from 626 patients (Group B) from 1989 until 2000.
Results:
In Group B microbial contamination was found in 74 PBPC products (5.2%) from 57 patients. In Group A microbial growth was detected in 3 leukapheresis products (0.8%) from 3 patients. After exclusion of PBPC products, which were probably contaminated before manipulation, statistical analysis showed a significant difference (chi2= 10.339; p < 0.001).
Conclusion:
These data suggest an impact of clean room conditions on the bacterial contamination rate of PBPC products. To identify confounding variables, variables like technique of leukapheresis, culture methodology, and microbial colonization of central venous catheters were taken into account. Further variables might be identified in following studies.
Insights
Implementing clean room conditions significantly reduced microbial contamination in peripheral blood progenitor cell (PBPC) products. This improvement is crucial for reducing infection risk in immunocompromised patients undergoing transplantation.
Area of Science:
- Hematology
- Microbiology
- Infectious Disease
Background:
- Patients undergoing high-dose chemotherapy and PBPC transplantation face high infection risks due to immunosuppression.
- Microbial contamination of PBPC products is a significant concern in patient safety.
Purpose of the Study:
- To analyze the rate of microbial contamination in ex vivo processed PBPC products.
- To compare contamination rates between preparation under clean room conditions versus standard laboratory conditions.
Main Methods:
- A prospective study (Group A) analyzed 366 PBPC harvests under certified clean room conditions (2000-2002).
- A historical control group (Group B) of 1413 PBPC products processed under standard laboratory conditions (1989-2000) was used for comparison.
- Good Manufacturing Practice conditions were implemented in participating institutions.
Main Results:
- Microbial contamination was found in 5.2% of PBPC products in Group B (standard conditions).
- In contrast, only 0.8% of PBPC products showed microbial growth in Group A (clean room conditions).
- Statistical analysis revealed a significant difference (p < 0.001) in contamination rates.
Conclusions:
- Clean room conditions significantly reduce bacterial contamination rates in PBPC products.
- Further studies are needed to identify other confounding variables impacting contamination.
- Implementing GMP and clean room environments is vital for enhancing PBPC product safety.
