Elevation of ST2 protein levels in cerebrospinal fluid following subarachnoid hemorrhage

Objective - To study the mode of appearance of ST2 in cerebrospinal fluid (CSF) after subarachnoid hemorrhage (SAH). Materials and methods - Immunoprecipitation and subsequent immunoblotting were performed to reveal the existence of ST2 in CSF after SAH. CSF samples from 21 patients were analyzed for ST2 using an enzyme-linked immunosorbent assay system. The ST2 levels were compared between serum and CSF after SAH. The ST2 levels in CSF were measured in six patients operated with other than SAH. Results - ST2 was secreted into CSF after SAH. The concentration of ST2 was the highest in the samples of the first post-operative day and declined thereafter. The patients operated with other than SAH did not show the elevation of ST2 in CSF. Conclusions - This study revealed the presence of ST2 in CSF for the first time and suggested a possibility that ST2 is related to the inflammatory reaction in the central nervous system after SAH.