Complement component 5 does not interfere with physiological hemostasis but is essential for Escherichia coli-induced coagulation accompanied by Toll-like receptor 4

There is a close cross-talk between complement, Toll-like receptors (TLRs) and coagulation. The role of the central complement component 5 (C5) in physiological and pathophysiological hemostasis has not, however, been fully elucidated. This study examined the effects of C5 in normal hemostasis and in Escherichia coli-induced coagulation and tissue factor (TF) up-regulation. Fresh whole blood obtained from six healthy donors and one C5-deficient individual (C5D) was anti-coagulated with the thrombin inhibitor lepirudin. Blood was incubated with or without E. coli in the presence of the C5 inhibitor eculizumab, a blocking anti-CD14 monoclonal antibody (anti-CD14) or the TLR-4 inhibitor eritoran. C5D blood was reconstituted with purified human C5. TF mRNA was measured by quantitative polymerase chain reaction (qPCR) and monocyte TF and CD11b surface expression by flow cytometry. Prothrombin fragment 1+2 (PTF1·2) in plasma and microparticles exposing TF (TF-MP) was measured by enzyme-linked immunosorbent assay (ELISA). Coagulation kinetics were analyzed by rotational thromboelastometry and platelet function by PFA-200. Normal blood with eculizumab as well as C5D blood with or without reconstitution with C5 displayed completely normal biochemical hemostatic patterns. In contrast, E. coli-induced TF mRNA and TF-MP were significantly reduced by C5 inhibition. C5 inhibition combined with anti-CD14 or eritoran completely inhibited the E. coli-induced monocyte TF, TF-MP and plasma PTF1·2. Addition of C5a alone did not induce TF expression on monocytes. In conclusion, C5 showed no impact on physiological hemostasis, but substantially contributed to E. coli-induced procoagulant events, which were abolished by the combined inhibition of C5 and CD14 or TLR-4.

Prostatic specific antigen and prostatic acid phosphatase in the monitoring and staging of patients with prostatic cancer

Serum prostatic specific antigen and prostatic acid phosphatase levels were measured retrospectively and evaluated in 357 men with benign prostatic hypertrophy and in 209 men with various stages of prostatic carcinoma. Although prostatic specific antigen values were elevated in 21 per cent of the patients with benign prostatic hypertrophy, the elevations usually were low and did not interfere with clinical interpretation. Prostatic specific antigen was elevated in 98 per cent of 86 men with active stage D2 disease; in 22 per cent of the men prostatic specific antigen was the only elevated marker. In contrast, prostatic acid phosphatase was the only elevated marker in 1 per cent of the patients with stage D2 disease and neither marker was elevated in 2 per cent. Among 74 patients in whom prostatic specific antigen and prostatic acid phosphatase determinations were made before radical prostatectomy, prostatic specific antigen was elevated substantially (greater than 10 ng. per ml.) in 59 per cent (26 of 44) with extracapsular disease and in only 7 per cent (2 of 30) without extracapsular disease. More importantly, of those 28 patients with substantially elevated prostatic specific antigen levels 26 (93 per cent) had extracapsular disease. Serial serum measurements showed that prostatic specific antigen either reflected or predicted clinical status in more than 97 per cent of the patients. We conclude that prostatic specific antigen is an excellent serum tumor marker for monitoring patients with prostatic carcinoma and that it surpasses prostatic acid phosphatase in this regard. Prostatic specific antigen also may be useful in staging prostatic carcinoma and it may change our attitudes significantly about the therapeutic responses to this cancer.