CD40 and Sepsis: Down‐regulated monocyte HLA‐DR and CD86 expression, and up‐regulated monocyte CD40 and CD80 expression have also been reported in septic patients.33, 34 Reduced HLA‐DR and CD86 expression has been hypothesized to be in part due to reduced antigen presentation in these patients.34 However, the underlying mechanisms that drive immunomodulation of host defences in sepsis and surgical patients remain unclear.