Implant of mesenchymal cells decreases acute cellular rejection in small bowel transplantation

Objective

The objective of the study was to show adipose tissue-derived mesenchymal stem cells (AD-MSCs) immunomodulatory effects in small bowel transplantation (SBTx).

Materials and methods

Forty Wistar Han rats (age: 10-12 weeks): were allogenic receptor rats and were allotted in 2 groups. Control group: rats undergoing orthopic SBTx ; AD-MSCs group: rats undergoing orthotopic SBTx plus AD-MSCs. Male Lewis rats were allogeneic small bowel donors. Rejection was confirmed by histological study of the explanted intestine, enterocyte apoptosis was determined in crypts and the lamina propria of the small bowel. Cytokine concentration levels (enzyme-linked immunosorbent assay) (interleukin [IL]-4, IL-10, IL-12, IL-17, IL-21, IL-23, tumor necrosis factor-alpha, and transforming growth factor [TGF]-b1) and cell percentages (flow cytometry) (CD3+ CD4+, CD8+, CD4+/25+, CD8+/25+, CD4+/25+/Foxp3+, and CD8+/25+/Foxp3+) were assessed in peripheral blood preoperatively and after death.

Results

Treatment with AD-MSCs produced a significantly lower risk of rejection in the first 7 post-operative days (five rejection cases among 20 rats in the control group and only one case in the AD-MSCs group). T_reg cells and TGFb1 levels showed a significant increase in the AD-MSCs group.

Conclusions

The local implantation of AD-MSC in the anastomosis and the intestinal lumen can induce a regulatory immune response, by increasing the percentages of Treg cells and TGb-1 levels, leading to a lower risk of acute rejection by cell mediation, in the first 7 days of the intestinal transplant. We think that the implantation of AD-MSCs, in the anastomoses and in the lumen of the donor intestine, could give rise to a chimera of donor-recipient cells.

Abdominal wall transplantation in organ transplantation: Our experience

Abdominal wall transplantation has been consolidated as an alternative to primary abdominal wall closure in intestinal and multiple organ transplant recipients. Given that it is feasible to obtain the visceral graft and the abdominal wall graft from the same donor, abdominal wall transplantation could offer satisfactory outcomes and be easily coordinated. Non-vascularized fascia is one of the alternatives for abdominal wall closure in transplantation. We report two cases of non-vascularized fascia transplantation in intestinal and multivisceral transplants, respectively. Both donors were young (23 and 18 years old). Both recipients had endured multiple previous surgeries, and no surgical alternatives for primary wall repair could be offered. In both cases, a complete abdominal wall flap was retrieved from the donor, however, due to the characteristics of the recipient's abdominal wall defect, only non-vascularized fascia was used after removing skin and subcutaneous cellular tissue from the graft. Abdominal wall transplantation is an option to consider for abdominal wall closure in patients with multiple previous surgeries and no alternatives for primary wall repair.