Serum concentrations of activin and follistatin are elevated and run in parallel in patients with septicemia

Objective: Activin is a growth and differentiation factor of many cell types, and has recently been implicated in inflammatory processes. Clinical data linking activin and its binding protein, follistatin (FS), are lacking. We measured serum levels of activin and FS in patients diagnosed with septicemia. Patients and measurements: Eight male and seven female patients of different ages, various forms of septicemia and different clinical outcome were investigated and compared with age- and sex-matched healthy controls. Serum concentrations of FS, activin, C-reactive protein (CRP) and blood leukocyte counts were determined during septicemia. Results: The median of the maximum activin concentrations of septicemic patients was 3.9-fold higher than in age- and sex-matched healthy control subjects (P < 0.01); the median of the maximum FS concentrations was 2.6-fold higher (P < 0.01). The highest increase of activin in septicemic patients was approximately 15.8-fold, whereas FS increased by up to 13.2-fold above normal. FS, activin and CRP serum levels generally paralleled each other, but were not correlated with leukocyte counts or clinical outcome. Conclusions: Circulatory concentrations of activin and FS are elevated in patients diagnosed with septicemia, consistent with potential roles in the systemic inflammatory response.