ALB and tick-borne encephalitis: The cerebrospinal fluid (CSF) of TBE patients is characterized by the increased albumin concentration and albumin CSF/serum index persisting during the convalescent period, indicating protracted BBB disruption, elevated IgG index pointing to the intensive intrathecal humoral response [17], and a tendency for a relatively low initial pleocytosis with a high neutrophil fraction [4, 18].