Background: We performed a laboratory and clinical evaluation of Kroma iT (Linear Chemicals S.L), an immunoturbidimetric analyzer for the detection of fecal occult blood.
Materials and methods: After a familiarization period, the imprecision, linearity of dilution and carry-over were determined and a clinical evaluation was performed on 210 patients.
Results: Within-run imprecision ranged between 1.06% and 8.04%. Between-run imprecision ranged between 3.11% and 13.09%. Linearity of dilution revealed a mean recovery of all dilutions of 95.24%, with a standard deviation of 7.47%. No carry-over was detected. The clinical evaluation demonstrated that the mean hemoglobin levels of the fecal immunochemical test values from patients with advanced neoplasms (colorectal cancer plus advanced adenoma) were significantly higher than those of cases with a normal colonoscopy examination. Sensitivity for advanced neoplasms at cut-off values between 80 and 300 ng/ml (6.4-24 mg Hb/Kg feces) ranged from 45.5% to 36.4% and the specificity ranged from 86.8% to 92.3%. The positive predictive values for detecting colorectal cancer and advanced adenomas were 5.4-6.4% and 27-34% respectively and the negative predictive value ranged from 92.5% to 91.7%. Using two samples per patient, a substantial increase of sensitivity was observed, with only a slight decrease in specificity.
Conclusion: Kroma iT analyzer is easy to handle and safe for personnel to use. Its analytical and clinical performance makes it suitable for use in a clinical chemistry laboratory for the early detection of advanced neoplasms.
Keywords: Colorectal cancer; Kroma iT; analyzer evaluation; fecal occult hemoglobin.