Changes in Complement Levels and Activity of Red Blood Cells, Fresh Frozen Plasma, and Platelet Concentrates During Storage.

Complement cascade plays an important role in the field of transfusion medicine. The study aimed to detect the complement levels of different blood components and different blood types to explore the risk of transfusion of stored blood. The samples including red blood cells (n = 110), fresh frozen plasma (n = 120), and platelet concentrates (n = 104) from healthy blood donors in our center were collected. Complement components (C3, C4, C3b, C3d, and CH50) were assayed to evaluate the activation of complement. The complement levels of various blood components at different storage times were observed. The differences in complement levels of four blood types in various blood components were compared. The complement levels of red blood cells in storage were low, with no significant changes (P > 0.05). C3b and C3d levels in platelets began to significantly increase after storage for 3 days (P < 0.05). The fresh frozen plasma during storage had higher complement levels, and the concentrations of C3 and C4 decreased and C3b and C3d increased at month 4 (P < 0.05). The differences in complement levels of four blood types in various blood components did not significantly change (P > 0.05), but the C3b and C3d levels of AB fresh frozen plasma remained stable during storage, which different from other blood types. The transfusion of red blood cells was relatively safe in terms of complement activation. The activation of complement proteins occurred during the storage of platelet and plasma, except group AB plasma.

An experimental study on riboflavin photosensitization treatment for inactivation of circulating HCT116 tumor cells.

Surgical resection is one of the most common radical treatments for cancers. However, tumors may be compressed or the local intravascular pressure may be increased during surgical manipulation, causing the shedding and entry of tumor cells into the blood circulation and hence distant recurrence and metastasis of tumors. We have preliminarily established a method of riboflavin photosensitization treatment (RPT) for inactivation of circulating tumor cells. This technology promises to solve the problems of shedding and entry of solid tumor cells into blood circulation before surgical manipulation, and almost unavoidable hematogenous dissemination of tumor cells during surgical resection. In the present study, apoptosis detection and tumorigenicity experiment in immunodeficient mice were conducted to evaluate the effect of RPT for inactivation of circulating tumor cells respectively. Next, functional evaluation was carried out for the immune cells through detecting apoptosis rate and cytokine secretion of lymphocyte. Finally, thromboelastography (TEG) and free hemoglobin were detected to assess peripheral blood coagulation and red blood cell damage. The results showed that RPT (50 µmol/L riboflavin, 10.8 J/cm2 UV) could effectively make tumor cell lose the ability of proliferation in the peripheral blood. In the meantime, the damage caused to peripheral blood coagulation, immune cell function and red blood cells was generally acceptable. The results of the study showed that RPT had huge potential in addressing the problems of shedding and entry of solid tumor cells into blood circulation before surgical manipulation, and almost unavoidable hematogenous dissemination of tumor cells during surgical resection. This therapy is expected to be an auxiliary and supportive method to reduce the risk of hematogenous metastasis and recurrence of cancers, and to increase the surgical success rate of malignant solid tumors.