Interference of hematocrit in the tacrolimus II microparticle enzyme immunoassay.

The authors studied the effect of hematocrit, bilirubin, and alkaline phosphatase on microparticle enzyme immunoassay for tacrolimus II (MEIA II) using specimens of whole blood obtained from 33 patients undergoing cyclosporine treatment. Tacrolimus was added to these samples at a final concentration of 7.5 microg/L and 15 microg/L. Both coefficients of variation were over 20% (21% at 7.5 macrog/L of tacrolimus and 22% at 15 microg/L of tacrolimus). No correlation was found between bilirubin and tacrolimus concentrations or between alkaline phosphatase and tacrolimus concentrations. On the other hand, negative correlations were found between hematocrit values and tacrolimus concentrations (r2 = 0.47; P < 0.0001 at 7.5 microg/L tacrolimus, r2 = 0.54; P < 0.0001 at 15 microg/L tacrolimus). Negative correlations were also found between hematocrit and the tacrolimus concentration using normal human red blood cells diluted with physiological saline solution (r2 = 0.93; P < 0.0001 at 7.5 microg/L tacrolimus, r2 = 0.91; P < 0.0001 at 15 microg/L tacrolimus). The results showed that the hematocrit interferes with the MEIA II for tacrolimus, and the magnitude of the interference is clinically significant. Beyond the normal range of hematocrit values, caution should be exercised in interpreting results as one may need to compensate for the levels of tacrolimus.

Usefulness of soluble dietary fiber for the treatment of diarrhea during enteral nutrition in elderly patients.

OBJECTIVES: We investigated the clinical usefulness of soluble dietary fiber (SDF) for the treatment of diarrhea during enteral nutrition in elderly patients. METHODS: This study included 10 men and 10 women (mean age +/- standard deviation: 79.3 +/- 5.1 y) who had diarrhea during long-term nutrition management. When administering SDF, the initial dose was 7 g and thereafter gradually increased at 1-wk intervals. After 4 wk, the administration was discontinued for 2 wk to confirm the effects of SDF. RESULTS: After the administration of SDF, serum diamine oxidase activity significantly increased (P < 0.001): The water content of the feces decreased significantly after the administration of fiber (P < 0.01). The frequency of daily bowel movements also decreased significantly (P < 0.05). Simultaneously, the fecal features improved. Concerning intestinal flora, there were no significant changes in the total number of bacteria or the number of anaerobic bacteria. The fecal pH decreased significantly 4 wk after the administration of fiber (P < 0.05). The total level of short-chain fatty acids increased significantly 4 wk after the administration of fiber (P < 0.05). There were no significant changes in the various nutritional indices. CONCLUSIONS: The administration of SDF is useful for controlling spontaneous, favorable bowel movement by improving symptoms of small intestinal mucosal atrophy and normalizing the intestinal flora.