IL6 and Alzheimer disease: For example, CSF concentrations of interleukin (IL)-6 were lower in participants with DLB compared with participants with AD and controls in one study,49 while other studies have found higher peripheral levels of IL-6 in DLB compared with controls,50 51 and another study has observed no differences in CSF IL-6 (or IL-1β) among DLB, AD or control groups.52