Summary: Soluble CD27 (sCD27) is a potential biomarker for diseases involving immune dysfunction. As there is currently little data on cerebrospinal fluid (CSF) sCD27 concentrations in the general population we measured CSF and plasma concentrations in 486 patients (age range 18–92 years, 57% male) undergoing spinal anesthesia for elective surgery. Across the complete cohort the median [range] sCD27 concentrations were 163 [400,000] pg/mL in plasma. Plasma sCD27, age and Qalb were the factors most strongly associated with CSF sCD27 levels. Reference sCD27 concentration intervals (central 95% of values) in a sub-group without the indication of neuropsychiatric, inflammatory or systemic disease (158 patients) were <50 pg/mL – 419 pg/mL for CSF and 2344–36422 pg/mL for plasma. These data provide preliminary reference ranges that could inform future studies of the validity of sCD27 as a biomarker for neuro- and systemic inflammatory disorders.
