BACTERIAL DECONTAMINATION OF BLOOD STEM-CELL APHERESIS PRODUCTS

High-dose chemotherapy using autologous bone marrow or mobilized blood as the source of stem cells for haematologic rescue, is being widely used for a variety of haematological malignancies and solid tumours. T o collect sufficient numbers of haematopoietic stem cells for successf ul engraftment, standard apheresis procedures are performed. Newer tec hniques and refinements of the procedure allow using only 1 to 2 apher esis products (AP) for autografting. Bacterial contamination of the AP , although very rare, sometimes occurs and may lead to generalized inf ection in the recipient. The apheresis must be repeated, sometimes eve n including time-consuming and costly mobilization. At our institution , the patients' blood stem cells are usually mobilized with chemothera py followed by daily s.c. haematopoietic growth factor injections or w ith growth factor alone. An apheresis machine is used for collection t hrough a central venous line and the AP is routinely checked for bacte rial contamination. Results are only available after the product has b een processed and cryopreserved. In the last 5 years, we observed bact erial contamination in four of our AP. Therefore, we investigated the possibility of in vitro antibiotic decontamination. Using standard ant ibiograms, we determined the sensitivities of the contaminating bacter ia. By incubating the products with the specific antibiotics at bacter icidal concentrations, we were able to sterilize the probes from the c ontaminating bacteria. In the concurrently performed controls without the active substance, bacteria were still detectable. We conclude that in selected cases, in vitro decontamination using pretested antibioti cs, may be a feasible, cost-effective, and easy alternative to perform ing additional apheresis procedures. (C) 1998 Wiley-Liss,Inc.