Evaluation of calprotectin level in intestinal content as an early marker for graft rejection.

HERNÁN CAGNOLA; HORACIO SCAVRONATTI; CABANNE, ANA; BIANCHI CLAUDIA; GRUZ, FERNANDO; ERREA AGUSTINA; ZAMBERNARDI, AGUSTINA; DOMINIK MEIER; FERNANDO CHIRDO; GUILLERMO DOCENA; GABRIEL E. GONDOLES; M RUMBO

TRANSPLANTATION PROCEEDINGS

ELSEVIER SCIENCE INC

Lugar: Huston; Año: 2010 p. 57 - 61

0041-1345

<!-- /* Font Definitions */ @font-face {font-family:Tahoma; panose-1:2 11 6 4 3 5 4 4 2 4; mso-font-charset:0; mso-generic-font-family:swiss; mso-font-pitch:variable; mso-font-signature:1627421319 -2147483648 8 0 66047 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:none; mso-layout-grid-align:none; punctuation-wrap:simple; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-font-kerning:14.0pt; mso-fareast-language:ES-AR;} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> Introduction: Diagnosis of rejection after intestinal transplant is still performed by endoscopic biopsy monitoring. Less invasive diagnostic procedures are desirable,although they are not available so far. Calprotectin, a stable cytosolic granulocyte protein, previously used as marker of inflammatory processes, has been proposed as a biochemical marker for rejection. The aim of the present work was to analyse the concordance between the calprotectin level in intestinal content and the presence of graft rejection after small bowel transplantation. Methods: Calprotectin level was measured using a commercial ELISA kit on 137 samples of intestinal content randomly collected during endoscopies performed on 11 ITx patients along 2 years of follow up. Calprotectin determinations were correlated to histological and clinical findings. The cut-off level was determined retrospectively by ROC analysis. Results: Based on histological findings and clinical record, samples were sort out as rejection samples (37/137), samples with absence of rejection (35/137) and samples with no clinical, endoscopic or histologycal findings (65/137). A cut-off value of 65 μg of calprotectin/g of intestinal content provided the best assay parameters according to clinical findings: 76 % sensitivity and 47 % of specificity. False positive results were found and they corresponded to patients with gastrointestinal infections (13%), systemic infections (13%), ulcers (10%) or unspecific histologycal alterations of the mucosa (15%). The other false positive cases corresponded to postsurgical samples (4%), or patients with concomitant gastrointestinal sympotms (2%). Most of the false negative results (78%) were observed during the recovery of severe acute rejection episodes, in patients successfully treated. In these cases, epithelial reconstitution and no mucosal infiltration was observed. If the latter group were discarded,,sensitivity would rise to 93 %; specificity, to 50% and negative predictive value, to 96%. Furthermore, a weak correlation was observed between calprotectin levels and the severity of rejection. Conclusions: This study confirm the results obtained by other groups:, fecal calprotectin dosage has a good sensitivity with low specificity for diagnosing intestinal rejection, since high calprotectin level can also be found in other clinical conditions. Nevertheless, it might be used as a first line of continiuous evaluation of the intestinal transplantation status, like other biochemical parameters that are used in kidney or liver transplantation, before considering the need for a biopsy.