Background: Leukapheresis is often performed in cancer patients to harvest stem cells, manufacture therapeutic vaccines, or follow immunologic response to therapy. We have recently described the minimal impact of leukapheresis on normal donors. Here we provide additional immunologic data from patients with advanced cancer who underwent leukapheresis.
Methods: Using data from cancer patients on clinical trials who had leukapheresis (n = 64) or peripheral blood draws only (n = 90) as controls for immune analysis, we evaluated the impact of leukapheresis on number and function of lymphocytes.
Results: In the leukapheresis group, median age was 63.5 (range 38-82); 87.5 % were male. Comparing pre- and post-leukapheresis values within the groups, with each patient as its own control, there was no significant difference in enzyme-linked immunosorbent spot (ELISPOT), antivector humoral response, absolute lymphocyte count (ALC), or T cell number. Twelve patients completed three leukaphereses with subsequent ELISPOT analysis; seven had increased responses to flu (1.1- to 2.3-fold) with an even distribution around no change. Nineteen patients had matched ALC values after completing three leukaphereses with no significant change from baseline.
Conclusions: These data provide evidence that leukapheresis has no detectable effects on a cancer patient's immune system in terms of number or function. These results contribute to a growing body of evidence refuting the hypothesis that a patient's immune competence is meaningfully affected by the procedure. Limitations include a restriction to 2-L leukapheresis procedure and small sample size.
Keywords: Apheresis; Clinical trial; Immunotherapy; Vaccine.