Effects of human serum on the release of haemopoietic growth factors

Abstract

S ummary . Unstimulated peripheral blood cells incubated without serum release unexpectedly high amounts of colony‐stimulating activity (CSA) and burst‐promoting activity (BPA). This ‘basal’release of haemopoietic growth factor activity is strongly reduced by the presence of normal human serum. Serum from patients with aplastic anaemia partly lacks this inhibitory activity on the release of CSA and BPA.