Hege Tøn

OBJECTIVE: Fecal calprotectin concentration in stool has recently been proposed as a marker of colonic neoplasm and inflammation, but the intraindividual day-to-day variability has so far received little attention. The present study was undertaken to determine the biological variability of fecal calprotectin in patients referred for colonoscopy. METHODS: A prospective design was applied. In each of 14 consecutive patients submitted for colonoscopy, eight stool samples were collected before the endoscopy. A detailed questionnaire was used. Calprotectin was measured by quantitative enzyme-linked immunoassay, and standard deviation for the within-patient variability was estimated from one-way analysis of variance. RESULTS: In absence of colonic neoplasm and inflammation, two populations of patients emerged: one (36%) with remarkably low and stable fecal calprotectin values all within the recommended cut-off of 50 microg/g, and one (64%) with labile values also beyond this limit. In this latter group. fecal calprotectin was 70 microg/g (mean) (single tests ranged from 9 to 461), and SD within patients was 52 microg/g, showing considerable day-to-day variation. History, concurrent diseases, or findings at colonoscopy could not explain labile values. A similar pattern was observed for spot variation in one stool sample from healthy volunteers, suggesting that factors other than disease contribute to the significant intraindividual biological variation of fecal calprotectin. CONCLUSIONS: Day-to-day variation of fecal calprotectin is considerable in patients without colonic inflammation or neoplasm, for whom the pattern of stabile low fecal calprotectin may seem to be a valid negative predictor. The origin and pattern of fecal calprotectin excretion deserve further attention.

BACKGROUND: The aim of this study was to evaluate fecal calprotectin in patients treated for colorectal cancer. Furthermore, the changes in fecal calprotectin concentration from before to after surgery were investigated. METHODS: In 155 patients with newly diagnosed colorectal cancer, two spot samples were taken from the same feces on two consecutive days. RESULTS: Three ways of evaluating calprotectin excretion were compared, (1st spot 1st stool; maximum of 1st spot 1st stool and 2nd spot 1st stool; maximum of 1st spot 1st stool and 1st spot 2nd stool) and gave similar results with median fecal calprotectin values 47 mg/l, 52 mg/l and 54 mg/l, respectively. Median calprotectin concentration did not differ significantly between different tumor stages, although the levels were slightly lower in Dukes stage A tumor than in the rest of the stages. Neither were there any differences in the concentrations related to the localization, size or the histological grading of the carcinoma. As the currently used cut-off level for fecal calprotectin is 10 mg/l, 87% of all patients had elevated fecal calprotectin. Seventy-nine percent of the patients had levels above 15 mg/l and 74% had levels above 20 mg/l (1st spot 1st stool). In patients who delivered fecal samples after the operation the calprotectin value fell significantly from a preoperative median value of 45 mg/l to 14 mg/l after the resection. CONCLUSIONS: The majority of patients with colorectal cancer have increased fecal concentration of calprotectin. One single fecal spot seems to be sufficient for determination of the calprotectin level. Measurement of fecal calprotectin may possibly become of value as a marker for colorectal cancer, although calprotectin, similar to fecal occult blood (FOB) tests, is a non-specific test for colorectal pathology, also being elevated in inflammatory bowel diseases. Further investigation of its specificity is therefore needed.

UNLABELLED: Fecal calprotectin (CPT) is elevated in the majority of patients with known colorectal cancer (CRC), but the specificity is not clarified. AIM: To evaluate if a CPT test (PhiCal ELISA) was more sensitive than Hemoccult II test in detecting colorectal neoplasia, and to obtain reference values in subjects with normal colonoscopy. To evaluate a possible relation between number and extent of dysplasia of adenomas in first degree relatives of patients with CRC and the stage of the carcinoma in the index casus. Further to study the prevalence of CRC and adenomas in the first degree relatives of patients operated for CRC. METHOD: In a multicenter study, 253 first degree relatives of patients with CRC, aged 50-75 years (mean age 60 years) underwent colonoscopy after having delivered stool samples and three Hemoccult II slides. RESULTS: In 237 first degree relatives from 148 patients with CRC, polyps were found in 118 (50%). Seventy three (31%) had adenomas and 17 had adenomas > or =10 mm. Five had asymptomatic cancers. The specificity of fecal CPT for adenomas at cut off levels <or =10, < or =15 and < or =20 mg/l were 47.4, 59.6 and 71.1%, respectively (max of three samples). The sensitivity at same cut off levels was 56.2, 45.2 and 31.5% and 4/5 of patients with carcinoma had CPT values >15 mg/l. The sensitivity of Hemoccult II for adenomas was 8%, and 4/5 of patients with carcinoma had negative Hemoccult II. The specificity for adenomas was 95%. CONCLUSION: Fecal CPT test was more sensitive than Hemoccult II in detecting colorectal neoplasia but the specificity was lower. In a high risk group like first degree relatives of patients with CRC, there are good reasons to consider fecal CPT as a first test in selecting patients for endoscopy.

Background: Diabetic nephropathy is one of the most serious and most frequent secondary complications of diabetes mellitus, resulting in increased morbidity and mortality rates. Microalbuminuria is the earliest stage of diabetic nephropathy and is characterized by a persistent and significant elevation in urinary albumin excretion. When quantifying urine proteins, creatinine measurements are used to correct for varying diuresis because creatinine is produced at an approximately constant rate. Methods: The Afinion AS100 Analyzer is a compact, benchtop, multiassay analyzer for point-of-care testing. The Afinion ACR assay presented here analyzes both the albumin and creatinine levels in a urine sample simultaneously within a single device. Albumin is quantified using an immunometric membrane flow through assay, using monoclonal antibody-coated membrane and monoclonal antibodies conjugated to colloidal gold. Creatinine is quantified using an enzymatic colorimetric test involving 4 enzymatic steps. At analysis completion, the concentrations of albumin, creatinine, and albumin-creatinine ratio (ACR) are shown on the Afinion AS100 Analyzer display screen. Results: Measurement ranges are 5 to 200 mg/L (albumin) and 16 to 340 mg/dL (creatinine). Both assays are linear over the whole dynamic range. Comparison of Afinion with Siemens DCA2000 and Roche Modular using 95 samples resulted in a linear correlation coefficient (r) of 0.99 for albumin (both methods) and 0.99 and 1.00, respectively, for creatinine. Total imprecision is 5.5% or lower for albumin, 3.8% or lower for creatinine, and 6.0% or lower for ACR. Conclusions: The Afinion ACR assay provides a reliable, precise, and convenient point-of-care method for simultaneous determination of albumin, creatinine, and ACR in 5½ minutes.