By extending our CSF profiling to patients with viral encephalitis (VE) and patients with CNS-involved hemophagocytic lymphohistiocytosis (HLH), for example, we are able to observe a breadth of CD8+ T-cell activation states (Supplementary Fig. S7), such that patients with VE and HLH harbored elevated levels of CD8+ T-cell activation that are rarely observed in other disease states including other ADS, MOGAD, and MS (Supplementary Fig. S7). Here, CD8A is linked to hemophagocytic syndrome.