Biological variation in circulating levels of mannan-binding lectin (MBL) and MBL-associated serine protease-2 and the influence of age, gender and physical exercise.

Mannan-binding lectin (MBL) and MBL-associated serine protease 2 (MASP-2) are central components of the MBL pathway of complement activation, and may have potential as clinical biomarkers in colorectal cancer (CRC). Prior to clinical usage, knowledge of the biological variations of the molecules is needed. We here investigate variations of MBL and MASP-2 in healthy persons over time and in relation to gender, age and physical activity. MBL and MASP-2 concentrations were determined in serum from healthy adults over a 3-week period and this was repeated 6 months later (n = 32); during a 24-h period (n = 16); and in relation to physical exercise (n = 14). Concentrations in serum and plasma were compared (n = 198). No significant variation over 6 months and no circadian variation was found for MBL (P = 0.39 and P = 0.34 respectively) or MASP-2 (P = 0.54 and P = 0.55). Physical exercise did not affect the levels (P > 0.8). Serum and plasma levels were only marginally different, and were independent of age and gender. Circulating levels of MBL and MASP-2 are stable over time in healthy individuals, which is advantageous for their potential application as biomarkers.

Impact of elective resection on plasma TIMP-1 levels in patients with colon cancer.

OBJECTIVE: Pre- and post-operative plasma tissue inhibitor of metalloproteinases-1 (TIMP-1) levels have a prognostic impact on patients with colorectal cancer. However, the surgical trauma may play an essential role in regulation of plasma TIMP-1 levels, which in turn may influence subsequent TIMP-1 measurements. PATIENTS AND METHODS: Consecutively, 48 patients with colon cancer (CC) and 12 patients with nonmalignant colonic disease were randomised to undergo elective laparoscopically assisted or open resection followed by fast track recovery. Plasma samples were collected just before and 1, 2 and 6 h after skin incision, and 1, 2, 8 and 30 days after surgery. TIMP-1 was determined concurrently in all samples by a validated ELISA method. RESULTS: Geometric mean preoperative TIMP-1 level was 142 ng/ml (range 54-559 ng/ml) among CC patients compared with 106 ng/ml (range 64-167 ng/ml) among patients with nonmalignant diseases (P<0.0001). TIMP-1 levels were decreased significantly 2 h after skin incision compared to the preoperative levels returning to preoperative levels at 6 h. A highly significant (P<0.0001) maximum level was observed 1 day after surgery and was decreasing to preoperative levels 30 days after surgery. Patients undergoing laparoscopically assisted or open resection had similar TIMP-1 levels at each time point. CONCLUSIONS: Major surgery has considerable impact on plasma TIMP-1 levels. Intra- and post-operative changes of plasma TIMP-1 levels are independent of the surgical approach, and resection for CC does not lead to a significant decrease of plasma TIMP-1 levels within 30 days postoperatively.

Influence of open versus laparoscopically assisted colectomy on soluble vascular endothelial growth factor (sVEGF) and its soluble receptor 1 (sVEGFR1).

INTRODUCTION: Minimal invasive colectomy may attenuate surgery-induced immunomodulation. This may in part be due to a reduced postoperative inflammation-mediated angiogenic stimulus directed by the proangiogenic factor VEGF and its neutralizing receptor VEGFR1. Thus, we evaluated perioperative plasma concentrations of soluble VEGF (sVEGF) and soluble VEGFR1 (sVEGFR1) in patients undergoing elective colectomy. METHODS: 60 consecutive patients were randomized to undergo laparoscopically assisted or open right or left sided colectomy. Blood samples were drawn preoperatively, intraoperatively and postoperatively until 30 days after the operation. Commercially available ELISA methods were used for determination of sVEGF and sVEGFR1. RESULTS: Patients with cancer (n = 48) had higher preoperative levels of sVEGF compared to patients with benign disease (n = 12) (p = 0.04), while there was no significant difference in sVEGFR1 levels (p = 0.053). Soluble VEGF (p < 0.0001) and sVEGFR1 (p < 0.0001) levels fluctuated intra- and postoperatively. However, the intra- and postoperative levels of sVEGF and sVEGFR1 were similar at all time points in patients undergoing laparoscopically assisted or open resection. CONCLUSION: Although significant fluctuation in sVEGF and sVEGFR1 concentrations during the perioperative period was shown, patients who underwent laparoscopically assisted resection had similar levels as patients who underwent open resection.

Bacterial antigen induced release of soluble vascular endothelial growth factor (VEGF) and VEGFR1 before and after surgery.

OBJECTIVE: The influence of surgery on release of soluble vascular endothelial growth factor (sVEGF) and the soluble inhibitory receptor (sVEGFR1) is unknown. The effect of major and minor surgery on variations in sVEGF and sVEGFR1 concentrations in vivo was studied, and on bacterial antigen-induced release of sVEGF and sVEGFR1 from whole blood in vitro. MATERIAL AND METHODS: Sixty-one patients with abdominal diseases undergoing five different surgical procedures were included in the study. Blood samples were drawn from patients before and after the operation. White blood cells and platelets were counted, and plasma sVEGF and sVEGFR1 were determined. Whole blood from each blood sample was stimulated in vitro with bacteria-derived antigens (lipopolysaccharides or protein A) and sVEGF and sVEGFR1 levels were subsequently determined in the supernatants. RESULTS: Neither sVEGF nor sVEGFR1 concentrations in plasma changed during surgery. In vitro stimulation of blood samples with bacteria-derived antigens resulted in a significant increase in sVEGF (p < 0.0001) and a less pronounced but still significant increase in sVEGFR1 (p < 0.01). Bacterial antigen-induced release of sVEGF correlated significantly with neutrophil cell counts (0.53 < r < 0.78; p < 0.0001). Bacterial antigen-induced sVEGFR1 release did not correlate with cell counts. CONCLUSIONS: Plasma sVEGF and sVEGFR1 concentrations did not change during surgery. In vitro bacterial stimulation led to increased release of sVEGF, which was not compensated for by an equivalent increase in sVEGFR1. There was a positive impact of major abdominal surgery on release of sVEGF. The bacterial antigen-induced changes in sVEGF may be related to the number of circulating neutrophils.

Elevated plasma levels of vascular endothelial growth factor and plasminogen activator inhibitor-1 decrease during improvement of psoriasis.

OBJECTIVE AND DESIGN: An evaluation of angiogenesis related molecules during open treatment of psoriasis. MATERIALS AND SUBJECTS: Plasma samples and skin biopsies from 16 patients with psoriasis and plasma samples from 13 healthy controls. TREATMENT: Ranitidine 300 mg orally twice daily for 6 months. METHODS: Vascular endothelial growth factor (VEGF) and plasminogen activator inhibitor-1 (PAI-1) were determined by ELISA methods in plasma collected from the patients before treatment and after 1, 3 and 6 months. Vessel counts were performed in biopsies from affected skin areas taken before treatment and after 3 and 6 months. The results were compared to simultaneous PASI scores. RESULTS: Pre-treatment plasma levels of VEGF and PAI-1 were significantly elevated in patients compared with levels in healthy persons (p = 0.02 and p = 0.04, respectively). The plasma levels decreased significantly during treatment (p = 0.03 and p = 0.01, respectively), and the decrease in combined levels correlated with the decrease in PASI score. However, the vessel density in affected skin did not change during treatment. CONCLUSIONS: Increased pre-treatment levels of VEGF and PAI-1 and decrease during improvement of the disease suggest that the two molecules may play a role in pathogenesis of psoriasis.

Bacteria-induced release of white cell--and platelet-derived vascular endothelial growth factor in vitro.

BACKGROUND AND OBJECTIVES: Poor prognosis after resection of primary colorectal cancer may be related to the combination of perioperative blood transfusion and subsequent development of infectious complications. White blood cell--and platelet-derived cancer growth substances, including vascular endothelial growth factor (VEGF), may be involved in this process. Therefore, we studied the in vitro release of VEGF from white blood cells and platelets stimulated by bacterial antigens and supernatants from stored red cell components. MATERIALS AND METHODS: Eight units of whole blood (WB) and eight units of buffy-coat-depleted red cell (SAGM) blood were donated by healthy blood donors. Subsequently, half of every unit was leucocyte depleted by filtration, and all 32 half-units were stored under standard conditions for 35 days. Just after storage, and on days 7, 21 and 35 during storage, aliquots of the supernatants were removed from the units and frozen at -80 degrees C. WB from other healthy donors was stimulated for 2 h with sodium chloride (controls), with Escherichia coli lipopolysaccharide (LPS) alone, or with LPS plus supernatants from the non-filtered or prestorage leucofiltered WB units (diluted 1:10), or from non-filtered or prestorage leucofiltered SAGM blood units (diluted 1:20) stored for 0, 7, 21, or 35 days, respectively. Similar assays were performed using Staphylococcus aureus-derived protein A as a stimulatory antigen. The concentration of VEGF was determined in supernatants from stored blood and in assay supernatants by using enzyme-linked immunosorbent assay (ELISA). RESULTS: The concentration of VEGF increased significantly (P < 0.0001) in a storage time-dependent manner in non-filtered WB and SAGM blood, while the increase was abrogated by prestorage leucofiltration. The supernatant concentration of VEGF was significantly increased in LPS-stimulated (P = 0.002) and in protein A-stimulated (P < 0.0001) assays compared with controls. Addition of supernatants from stored, non-filtered WB or SAGM significantly increased the assay supernatant VEGF concentration storage-time dependently (P = 0.006) in LPS assays. In protein A assays, only supernatants from non-filtered WB significantly increased the assay supernatant VEGF concentration storage-time dependently (P = 0.022). This additional effect by supernatants from stored blood components was not observed with prestorage leucofiltered blood. CONCLUSIONS: Extracellular VEGF may accumulate in non-filtered red cell components, but this can be prevented by prestorage leucocyte depletion using filtration. In addition, bacterial antigens appear to induce release of VEGF from white blood cells and platelets. Addition of supernatants from stored, non-filtered WB or SAGM blood may increase the VEGF levels in a storage time-dependent manner, while prestorage leucofiltration may prevent further increase by supernatants.