Clinical Usefulness of Fecal Cytokeratin-19 Assay with Rapid Test

Lee, Jehoon; Kim, Yonggoo; Kim, Myungshin; Lim, Jihyang; Yoon, Sangsoon; Han, Kyungja

Abstract

BACKGROUND: The fecal occult blood test (FOBT) is presently the only laboratory test for screening a population for colorectal cancer. However, the effectiveness of FOBT to reduce the mortality from colorectal cancer is still controversial. The cytokeratin-19 (CK-19) is highly expresssed in gastrointestinal (GI) epithelium. Therefore, fecal CK-19 excretion could be increased in gastrointestinal diseases.
METHODS
We estimated fecal CK-19 using cytokeratin-19 enzyme-linked immunosorbent assay (Roche Diagnostics, Mannheim, Germany) on 53 stool samples from patients with various GI diseases and 100 stool samples from control patients. We conducted a study of rapid fecal CK-19 test using gold immunochromatography developed by DiNonA Research Institute (Seoul, Korea) and the fecal occult blood test (FOBT) on 115 stool samples from patients with various GI diseases and 181 stool samples from control patients.
RESULTS
The cutoff value of fecal CK-19 was 408.7 pg/80mg. The sensitivity of the rapid fecal CK-19 kit was 10,000 epithelial cells /ml. The positive rate of rapid fecal CK-19 test was 4.4% in the controls, 83.9% in the thrombotic microangiopathy patients after BMT and it was higher than the positive rate of FOBT (58.1%, P=0.0264). In the overall GI diseases including GI cancers, the sensitivity of rapid fecal CK-19 test was 56.5%, and that of FOBT was 21.7%. The specificity of rapid fecal CK-19 test was 95.6%.
CONCLUSIONS
The rapid fecal CK-19 test in conjunction with the FOBT could be a valuable screening method for GI diseases especially for GI inflammation.