Clinical Study Of Large-scale Monocyte Collection For Cancer Immunotherapy

objectives To investigate the clinical efficiency and applicability of large-scale monocyte colletion in oncology patients who intend to receive dendritic cell (DC) immunotherapy.Study design and methods Mononuclear cell (MNC) collections were first performed as large volume leukapheresis (LVL)using the Cobe Spectra AUTO PBSC program in each patient in order to enrich the monocytes, then the purification processes were conducted subsequently in Gambro Elutra system. Cell counts were determined for peripheral blood before and after MNC collection, as well for the MNC products after leukapheresis by using automatic cell counter.Results Totally, 18 patients with various cancers are involved with a break of 2 to 3 weeks after end of their last cycle of chemo- or radiotherapy. The collection resulted in a PBV/TBV (processed blood volume/ total body blood volume) value at 3.17 (2.28 - 4.06). No significant anticoagulant related side effects were observed. MNC products contained 30.3%(13% - 58.3%)monocytes with absolute number at 2.80×109(1.50×109 - 3.58×109). The collection efficiency for monocyte by LVL was 50.5%(33.98% - 69.95%). FACS determination revealed the comparable result of monocytes collected within the MNC products at 2.52×109 ( 1.07×109 - 3.61×109), leading to a final yield of monocytes at 2.0×109(1.1×109 -2.9×109), purity of 86.1%(75.6% - 89.8%)and recovery of 81.8%(39.0% - 99.9%)respectively, after elutriation with Gambro Elutra system. The yield of monocyte was positively related to the peripheral blood WBC count before apheresis (P<0.005,r=0.67). However, the collection also led to decrease of peripheral blood WBC and platelet count after collection at 12.47%(3.82% - 19.16%)and 19.27%(9.6% - 33.0%)respectively.Conclusions Large volume leukapheresis in oncology patients can result in sufficient production of monocyte for the generation of DC vaccines. It is a suitable approach for clinical routine application for most of oncology patients in the purpose of receiving immunotherapy by using monocyte-derived DC vaccination, despite some clinical side effects may exist.