Th1 and Th2 subsets in orthopaedic surgery by single-cell cytokine analysis

Significant immunosuppression can occur following allogeneic blood transfusion or surgery. Cytokine stimulation controls immune responses and determines their type and intensity. Infusion of autologous or allogeneic blood provides elements, including cytokines, which may result in transfusion-associated immunomodulation. This study investigates to what extent autologous/cell salvage transfusions affect levels of intracellular cytokines interferon-gamma and interleukin-4, and if this indicates a shift in the T-helper 1/T-helper 2 cell ratio using a novel method of detecting intracellular cytokines, the Magnetic Activated Cell Sorter Cytokine Secretion Assay (MACS Assay). Comparisons were made between patients receiving autologous blood or no blood transfusion, for pre- and post-operation levels of interferon-gamma and interleukin-4. Interferon-gamma producing T-helper 1 cells decreased post-operatively. Concomitantly, interleukin-4 producing T-helper 2 cells increase. These results demonstrate a measurable shift from T-helper 1 to T-helper 2 cells post-operatively. Secondly, the study showed surgery alone instigates the same level of immunomodulation as autologous/cell salvage blood transfusion in combination with surgery.