Paneth and Stem Cells are not affected during initial stages of acute cellular rejection in small bowel transplantation in humans.

PUCCI-MOLINERIS, MELISA; GONZALEZ-POLO, VIRGINIA; JUAN PABLO SANTILLI; CAROLINA RUMBO; HECTOR SOLAR MUNIZ; MARTIN RUMBO; GABRIEL E. GONDOLESI; DOMINIK MEIER

New York

Congreso; CIRTA 2017; 2017

Introduction: In spite of the last developments and improvements in long term outcome after intestinal transplantation, acute cellular rejection (ACR) remains as the most common cause of graft loss. The diagnosis of ACR is still based on pathological findings, but it is unclear, which cell type and which crypt zone (bottom (BZ) or transit-amplifying zone (TZ)) are the main target cells. Therefore, we wanted to elucidate which crypt zone is mainly disturbed by apoptosis and whether the early target cells of ACR are Paneth cells (PC) or stem cells (SC). Methods: Paraffin embedded intestinal biopsies from ITx-patients classified by an experimented pathologist as normal (N;n=8) or with mild (MR;n=8) or moderate (MoR;n=8) ACR were used. Immunofluorescent and histochemical detections were performed with anti-α-defensin-5 (DEFA5), anti-interleukin-22 receptor (IL22RA1), anti-cleaved-caspase-3 (CASP3) antibodies to identify PC, SC and apoptotic events, respectively. Then, we quantified each marker and evaluated their co-localization. To support that, we analyzed the expression of DEFA5, lysozyme (PC marker), Leucine-rich repeat-containing G-protein coupled receptor 5(LGR5) and IL22RA1 genes (SC markers) by qPCR in N (n=5) and MoR (n=6) groups using biopsies from non-transplanted patient as normalizer (n=4). Results: Our results show that there was an increasing number of apoptotic bodies in BZ as the diagnosis worsens from N to MoR. Apoptosis in TZ during MoR exhibited statistical differences compared with BZ and the TZ in N group (P