Transplantation Technologies & Research

Mesenchymal stem cells are able to differentiate in various cell lineages and they have shown immunomodulatory properties in vitro, altering the cytokine secretion profile of T helper, T effector and dendritic cells and stimulating natural killer cells towards an anti-inflammatory and tolerant phenotype. In vivo they prolong skin allograft survival and may decrease graft-versus-host disease after hematopoietic stem cell transplants. In this work we studied the effects of mesenchymal stem cell treatment in an allogeneic heterotopic heart-lung transplant model.

The following experimental groups were formed: A) Control B) Immunosuppressive therapy (Cyclosporine A) C) Mesenchymal stem-cell intravenous infusion D) Mesenchymal stem-cell infusion plus immunosuppressive treatment.

The infusion of mesenchymal stem cells improved the mean graft survival up to 14.5±3.7 days with respect to the control group (3±0.6 days). Treatment with Cyclosporine A plus mesenchymal stem cells (group D) produced a mean survival time of 18.25±4.9 days, and was not significantly different to the results for group B (21.75±3.5 days). Furthermore, in the immunosuppressive treatment and the mesenchymal stem cell treatment, histological analysis revealed a reduction in the grade of rejection in heart and lung grafts. This decrease was most significant in group D.

In conclusion, mesenchymal stem cells alone or in combination with Cyclosporine A were able to prolong graft survival time. These data suggest that, in vivo, mesenchymal stem cells retain their ability, already shown in vitro, to suppress lymphocyte activation and proliferation.

Background: There is little information in literature on renal allograft biopsy findings in renal allograft dysfunction in live related renal transplant recipients.

Material and Methods: A retrospective review of 1210 renal allograft biopsies from 575 renal transplant patients was carried out over a period of seven years from June 1997 till December 2004. The demographic, clinical, laboratory and biopsy findings were collected and analyzed.

Results: A total of 1210 graft biopsies were performed on 575 patients. The mean age of recipients and donors was 29.2±9.7 years, and 35.7±10.5 years, respectively. The males were predominant among recipients (76.7 vs. 23.3%), while among donors they only slightly outnumbered females (51.8 vs. 48.2%).

Regarding pathological lesions, acute rejection was seen in 292 (24%) cases, followed by acute tubular injury and cyclosporine A (CsA) toxicity, found in 281 (23.2%) and 134 (11%) cases respectively. Chronic allograft nephropathy (CAN) with variable degree of tubular atrophy was seen in 361 (29.8%) cases. Seventy nine cases (6.5%) of acute pyelonephritis were detected on graft biopsies. A number of rare lesions were also found, including 13 (1.07%) cases of recurrent/de novo renal disease, and 13 (1.07%) of polyoma virus infection. Five cases of CsA induced hemolytic uremic syndrome (HUS) were also noted.

Conclusion: In conclusion, the incidence of acute rejection is low in our patients as compared to cadaveric renal transplant recipients as reported in Western studies and CsA toxicity is more common. Recurrent/de novo renal disease is uncommon in our patients.