Risks Of Organ Transplantation Research Articles

A blueprint for electronic utilization of ambiguous molecular HLA typing data in organ allocation systems and virtual crossmatch

Virtual crossmatch (VXM) compares a transplant candidate’s unacceptable antigens to the HLA typing of the donor before an organ offer is accepted and, in selected cases, supplant a prospective physical crossmatch. However, deceased donor typing can be ambiguous, leading to uncertainty in compatibility prediction. We have developed a prototype web application that utilizes ambiguous HLA molecular typing data to predict which unacceptable antigens are present in the donor HLA genotype as donor-specific antibodies (DSA). The application compares a candidate’s listed unacceptable antigens to computed probabilities of all possible two-field donor HLA alleles and UNOS antigens. The VIrtual CrossmaTch for mOleculaR HLA typing (VICTOR) tool can be accessed at http://www.transplanttoolbox.org/victor. We reanalyzed historical VXM cases where a transplant center’s manual interpretation of molecular typing results influenced offer evaluation. We found that interpretation of ambiguous donor molecular typing data using imputation could one day influence VXM decisions if the DSA predictions were rigorously validated. Standardized interpretation of molecular typing data, if applied to the match run, could also change which offers are made. HLA typing ambiguity has been an underappreciated source of immunological risk in organ transplantation. The VICTOR tool can serve as a testbed for development of allocation policies with the aim of decreasing offers refused due to HLA incompatibility.

Circulating biomarkers of tolerance.

On the basis of reviewed literature here we describe models of tolerance and summarize the evidence of circulating biomarkers suitable for the assessment of immunological risk in organ transplantation. We focused on results of evaluation of specific peripheral immune cell populations and transcripts in peripheral blood of operationally tolerant liver and kidney transplant recipients. Validation of described markers to define potentially tolerant patients before their use in clinical trials is critical.

Transplantation of a Kidney With a Renal Cell Carcinoma After Living Donation: A Case Report

Transmission of cancer is a serious risk in organ transplantation. We present a case of renal cell carcinoma (RCC) in a kidney obtained from a living donor. A 48-year-old mother was evaluated for donation to her 12-year-old daughter. Donor renal ultrasound, intravenous pyelography, and angiography were normal. A 5 × 5 mm nodule found on the surface of the kidney during harvesting was totally excised before transplantation. The histology revealed RCC with free margins at 2 weeks after transplantation. The immunosuppressive drugs consisted of cyclosporine, mycophenolate mofetil, and prednisolone. The graft function remained stable. Donor and recipient are without evidence of tumor recurrence at 15 months after transplantation. This experience indicated that donor kidneys with small, incidental RCC may be managed with excision and transplantation, without tumor recurrence in recipients who are informed of the potential risks of recurrence and metastases.

Accidental transplantation of a kidney with a cystic renal cell carcinoma following living donation: management and 1 yr follow-up

Transmission of cancer is a fatal risk in organ transplantation. We present a case of incidental renal carcinoma in a kidney obtained from a living donor. A 56-yr-old father was evaluated for donation for his 28-yr-old daughter. An MRT scan revealed two cysts in the right kidney. Right-sided donor nephrectomy and subsequent transplantation was performed. The wall of the prominent cyst was partially excised prior to transplantation. Histology revealed a high-grade renal clear cell carcinoma 10 d after transplantation. Following careful evaluation the recipient underwent partial nephrectomy. Immunosuppression was switched to rapamune. The graft function remained stable. Donor and recipient are without evidence of tumor recurrence 1 yr after transplantation. Our policy to obtain the kidney presenting anatomical variations proved to be beneficial for the donor. In case of transmission of cancer partial resection preserving graft function might be justified.