EFFECTS OF AGING IN AN EXPERIMENTAL MODEL OF INTESTINAL TRANSPLANTATION. PRELIMINARY RESULTS

GENTILINI M. VIRGINIA; PABLO STRINGA; ARRIOLA BENITEZ, P. CONSTANZA; NATALIA LAUSADA; JEREMIAS MOREIRA; IVANA IVANOFF; RODRIGO PAPPA-GOBI; MARTIN RUMBO; STEFAN G TULLIUS; GONDOLESI, GABRIEL E.

Congreso; REUNIÓN CONJUNTA SAIC SAI&FAIC SAFIS 2022; 2022

Older transplant recipients experience increased incidence of infection, malignancy, and death compared with younger patients, likely because of aging-associated immune senescence. Youthful allografts could theoretically drive rejuvenation, but the data are less clear. We aimed to evaluate the effects of aging in an experimental model of intestinal transplantation (ITx) Materials and Methods. Intestinal allografts from young Sprague-Dawley rats were transplanted in Wistar rats. Based on age of the recipient, two experimental groups were performed: 1-Old Recipient (OR, >9 months, n=4) and 2-Young Recipient (YR, 2 months, n=4). Intestinal graft and blood samples were collected at 30 minutes, 5, 7, 9 and 18 postoperative days (POD) after ITx. Graft and recipient survival, histopathological analysis in search of acute cellular rejection (ACR) signs (Wu Score), intestinal absorptive capacity; Kinetics of CD4 and CD8 frequency (flow cytometry) were compared between groups. Also, donor specific allorecognition were evaluated by Mixed Lymphocyte Reaction (MLR) assay (flow cytometry). Results: Despite the kinetic of histological ACR process was similar in both groups (mild to moderate at 7 POD, severe ACR at end-point), OR survived longer (OR: 14 vs YR: 8 POD) and showed lower percentage of body reduction than YR at the clinical endpoint (O: 20% vs Y: 25%). Glycemia curves were similar in both groups, demonstrating comparable graft absorptive capacity. During the ACR, a tendency to a reduction of CD4 (OR: 12% vs YR: 35%) and an increment in CD8 frequency (OR: 65% vs YR: 180%) in the gut was observed in both groups. Finally, a donor specific CD4 and CD8 allorecognition was demonstrated by MLR assays. Conclusion: Our preliminary results suggest that there is a difference in the ACR process depending on the recipient age. This study is currently being extended with a large number of animals