Positivity rates and performances of immunochemical faecal occult blood tests at different cut-off levels within a colorectal cancer screening programme.

BACKGROUND: Immunochemical faecal occult blood tests have greater sensitivity for colorectal cancer screening than guaiac-based tests; however the number of positive tests required is still under discussion. METHODS: A direct comparison of Hemoccult II with two immunochemical quantitative tests (OC-Sensor and FOB-Gold) using a 2-sample strategy was performed in over 30,000 patients undergoing colorectal cancer screening in France. RESULTS: Positivity ratio between immunochemical tests and Hemoccult II varied between 2.2 (OC-Sensor) and 2.4 (FOB-Gold) for the lowest cut-off value and 1.5-1.4 for the highest cut-off value. The positive predictive value for colorectal cancer was similar for immunochemical tests and Hemoccult II, and significantly higher for immunochemical tests for advanced adenomas. The detection rate of both colorectal cancer and advanced adenomas was higher with immunochemical tests than with Hemoccult II. With the 2-sample strategy and the lowest cut-off value the detection rate of colorectal cancer almost doubled and for advanced adenomas quadrupled. CONCLUSION: For colorectal cancer screening with immunochemical faecal occult blood tests, an acceptable strategy would be 2-day sampling with at least one positive test at a cut-off between 150 and 200 ng/mL (OC-Sensor) and 176 and 234 ng/mL (FOB-Gold). Data on the ease of test interpretation and cost-effectiveness now necessary to make definitive choices.

Fiber evanescent wave spectroscopy using the mid-infrared provides useful fingerprints for metabolic profiling in humans.

Fiber evanescent wave spectroscopy (FEWS) explores the mid-infrared domain, providing information on functional chemical groups represented in the sample. Our goal is to evaluate whether spectral fingerprints obtained by FEWS might orientate clinical diagnosis. Serum samples from normal volunteers and from four groups of patients with metabolic abnormalities are analyzed by FEWS. These groups consist of iron overloaded genetic hemochromatosis (GH), iron depleted GH, cirrhosis, and dysmetabolic hepatosiderosis (DYSH). A partial least squares (PLS) logistic method is used in a training group to create a classification algorithm, thereafter applied to a test group. Patients with cirrhosis or DYSH, two groups exhibiting important metabolic disturbances, are clearly discriminated from control groups with AUROC values of 0.94+/-0.05 and 0.90+/-0.06, and sensibility/specificity of 8684% and 8787%, respectively. When pooling all groups, the PLS method contributes to discriminate controls, cirrhotic, and dysmetabolic patients. Our data demonstrate that metabolic profiling using infrared FEWS is a possible way to investigate metabolic alterations in patients.

Sigma ESR: an erythrocyte sedimentation rate adjusted for the hematocrit and hemoglobin concentration.

The aim of the study was to simplify the first Sigma erythrocyte sedimentation rate (ESR) method (manual hematocrit adjustment to 0.35, sum of 4 sedimentation levels) and to confirm its clinical relevance. The erythrocyte sedimentation rate of undiluted blood samples from 576 patients was measured simultaneously with and without manual hematocrit adjustment to 0.35 to identify an approximate expression of the area under the curve and a formula for calculating the Sigma ESR. The Sigma ESR formula was based on the sum of 2 unadjusted sedimentation levels, at 30 and 60 minutes, together with the hematocrit value and the hemoglobin concentration. Sigma ESR values in 274 healthy subjects showed a gaussian distribution, no difference between men and women, and no significant increase with age. In recent-onset arthritis or disk-related lumbosciatic syndrome, Sigma ESR seemed to be a more reliable marker of inflammation than the Westergren ESR and C-reactive protein. We also obtained data clarifying the controversial relationship of ESR with lipid levels and arterial hypertension.

Serum ceruloplasmin and ferroxidase activity are not decreased in hepatic failure related to alcoholic cirrhosis: clinical and pathophysiological implications.

BACKGROUND: A decrease in serum ceruloplasmin (Cp), a protein involved in iron metabolism through its ferroxidase activity, is classically claimed to be observed in severe hepatic failure of non-wilsonian chronic liver disease and therefore to be a confounding factor for the diagnosis of Wilson's disease. Moreover, a simultaneous decrease in ferroxidase activity could be hypothesized as playing a role in the development of the hepatic siderosis frequently observed in advanced chronic liver diseases. The aim of this study was to test the validity of these two statements. METHODS: This study investigated Cp, determined by immunonephelometry, and its ferroxidase 1 activity determined by Erel's method in 33 male patients with severe alcoholic cirrhosis compared with 66 healthy male volunteers, selected on strict criteria. Each patient was age-matched with two controls. Nonparametric tests were used for statistical analysis. RESULTS: The mean values of Cp were significantly higher in cirrhotic patients as compared with control subjects. A significant elevation of Cp was also observed in the subgroup of 11 cirrhotic patients who had normal serum C-reactive protein levels. The mean values of ferroxidase 1 activity were similar to those obtained in control subjects. CONCLUSIONS: Low serum Cp should not be expected in severe hepatic cirrhosis of non-wilsonian origin. Hepatic siderosis in advanced chronic liver disease is likely to be unrelated to decreased ferroxidase activity.

Serum ceruloplasmin and ferroxidase activity are decreased in HFE C282Y homozygote male iron-overloaded patients.

BACKGROUND/AIMS: A body of evidence suggests that ceruloplasmin (Cp), the major serum copper-containing protein, acts in iron metabolism due to its ferroxidase activity which appears essential for iron movements and exchanges. METHODS: The present study investigated the serum levels of Cp and its ferroxidase activity in 53 C282Y homozygote genetic hemochromatosis (38 iron overloaded, 15 iron depleted) patients as compared to age and sex-matched healthy volunteers. RESULTS: Serum levels of Cp were significantly decreased in iron-overloaded male hemochromatotic patients vs. the control group (P=0.02). Furthermore, serum ferroxidase activity was strongly and significantly lower in iron-overloaded male hemochromatotic patients (P<0.001). In contrast, in iron-depleted male hemochromatotic patients, who were under maintenance therapy by regular phlebotomies, serum levels of Cp and ferroxidase activity were not statistically different from those observed in controls. CONCLUSIONS: These data: (i) show that serum Cp and ferroxidase activity are decreased when C282Y homozygote men are iron overloaded and normal when iron depleted; (ii) suggest that iron may modulate the Cp gene expression; and (iii) raise the issue of the putative role of decreased serum ferroxidase activity in the phenotypic expression of HFE-1 hereditary hemochromatosis.