Fecal calprotectin level measurements in small bowel allograft monitoring: A pilot study

BACKGROUND. Protocol endoscopy with biopsy is currently the gold standard of small bowel transplantion (SBTx) monitoring, however it is invasive, costly, needs skilled operator, may require anesthesia and may cause complications. We investigated fecal calprotectin level (FCL) as a candidate noninvasive marker for monitoring patients after SBTx. METHODS. A pilot study was performed to test the use of FCL measurement in following up SBTx patients. Ileostomy effluents were collected at various postoperative days before endoscopy and biopsy. FCLs were measured by enzyme-linked immunosorbent assay and a cut-off level of 100 ng/mg was considered positive. The results were retrospectively evaluated in combination with clinical, endoscopic, and histopathological findings. FCLs are presented as median nanogram per milligram. RESULTS. FCLs were measured in 122 samples that were obtained from 29 patients after SBTx. Only 1 of 69 positive FCL did not accompany abnormal findings. Retrospective evaluation showed that 11 samples from six patients (FCL: 217) coincided with rejection episodes, six samples from three patients (FCL: 125) coincided with viral enteritis, 51 samples from 21 patients (FCL: 207) coincided with nonspecific inflammation, 11 samples from two patients (FCL: 998) coincided with chronic intestinal ulceration, and finally 50 samples from 19 patients (FCL: 43) coincided with normal findings. No significant FCL difference was found between rejection, infection, and inflammation. FCL evolution in individuals showed that FCL can predict rejection days before histopathological diagnosis. CONCLUSION. FCL is a sensitive test for ongoing organic intestinal allograft pathologies. It might be useful as prescreening marker to avoid unnecessary endoscopies.