Levels of tissue inhibitor of metalloproteinases-1 in blood transfusion components

Blood transfusion during surgery for solid tumors may reduce patient survival because of various bioactive substances present in blood preparations. The anti-proteolytic protein tissue inhibitor of metalloproteinases-1 (TIMP-1) present in large quantities in platelets has been shown to stimulate cell growth and to inhibit apoptosis and may therefore be considered to influence tumor progression. We measured TIMP-1 levels in blood transfusion preparations. especially in platelet-containing preparations, before and after leucofiltration and at different time-points during storage. The mean TIMP-1 levels in whole blood (WB) and platelet-rich plasma (PRP) were slightly reduced by leucofiltration; WB: 41.6 microg/L versus 34.9 microg/L. PRP: 139.8 microg/L versus 127.2 microg/L. However, with prestorage leucofiltration. TIMP-1 levels in buffy-coat-derived platelet (BCP) pools were significantly reduced from 134.2 microg/L to 102.2 microg/L (p=0.0013). In saline-adenine-glucose-mannitol (SAG-M) blood preparations in which the platelet content is reduced by more than 99%,. TIMP-1 could not be detected. Extracellular TIMP-1 accumulated significantly in non-filtered WB and in aferesis platelet concentrates (APC), but TIMP-1 was at no time detectable in SAG-M blood during storage. In conclusion. TIMP-1 is present in various platelet-containing blood preparations, but not in platelet-free preparations such as SAG-M, indicating that most of the TIMP-1 measured in blood preparations originates from platelets. Furthermore, TIMP-1 levels increased during storage in preparations containing platelets. which suggests a continuous disintegration of platelets. These data imply that information on preoperative blood transfusions should be taken into account when evaluating plasma TIMP-1 levels in patients.