How much GMP do we need to infuse contaminated HPC and DLI products

We read with interest the article by Kelly et al.1 which emphasizes the importance of the clinical impact of infusion of haemopoietic progenitor cells (HPC)/donor lymphocytes (DLI) potentially contaminated with bacteria. They suggest that infusions of HPC/DLI, contaminated with bacteria do not cause significant clinical sequelae. However, there is no randomized trial that deals with this important topic. The increasing manipulation of HPC for transplantation and immunotherapy in clinical practice highlights the importance of maintaining sterility of the processed products.2 The sterility of HPC/DLI is of particular relevance because of the implementation of the EU directive 2004/23/EC in April 2006, which specifies good manufacturing practice (GMP), including the processing of haemopoietic progenitor cells-apheresis (HPC-A), haemopoietic progenitor cells-marrow (HPC-M) and DLI in certified clean rooms.3, 4, 5, 6, 7