Accuracy of the median channel shift in the flow cytometry for predicting complement dependent cytotoxicity crossmatching in kidney transplant candidates.

Crossmatching either by complement-dependent cytotoxicity (CDC) and/or by flow cytometry (FCXM) are routinely used for assessing anti-HLA donor antibodies before kidney transplantation. FCXM has demonstrated greater sensitivity and many transplant centers have opted for its use without the concomitant CDC assay. The objective of this study was to evaluate the accuracy of the median channel shift (MCS) in the FCXM in predicting the CDC assay results. A total of 1516 T cell FCXM and 1408 B cell FCXM were studied in deceased donors lymphocytes between January/2016 and March/2017. The high detection rate of CDC+ results by FCXM+ resulted in 87% (FCXM-T) and 90% (FCXM-B) sensitivity, and 98% negative predictive value, for both. The low specificity of FCXM B (43%) is atributed to cases of CDC-/FCXMB+. FCXM T and B were able to detect 53% and 76% of cases with donor specific antibodies of classes I and II with intensity of fluorescence ≥5001. The MCS differentiated CDC+ (Md, P25 and P75) results: MCS-T 390 (245-469) and MCS-B 282 (180-350). Through ROC curve analysis (AUC), the MCS showed satisfactory performance in detecting CDC+: MCS-T 0.909 (0.886-0.933) and MCS-B 0.775 (0.724-0.826). Considering the accuracy and sensitivity evaluation, the MCS-T 245 and MCS-B 282 cutoffs showed a better prediction of CDC+. This study showed that it is possible to calibrate MCS based on CDC+ with accuracy >90%, however, that leads to a risk in terms of non-detection of low-titer anti-HLA antibodies.

[Renal transplantation without maintenance immunosuppression. Identical twins and kidney transplantation following a successful bone marrow graft]. / Transplante renal sem imunossupressão de manutenção. Pares monozigóticos e receptores de rim e medula óssea do mesmo doador.

Renal transplantation without maintenance immunosuppression has been sporadically reported in the literature. The cases include non-adherent patients who discontinued their immunosuppressive medications, transplantation between identical twins, kidney transplantation after a successful bone marrow graft from the same donor and simultaneous bone marrow and kidney transplantation for the treatment of multiple myeloma with associated renal failure. There are also ongoing clinical trials designed to induce donor specific transplant tolerance with infusion of hematopoietic cells from the same kidney donor. Here we describe two cases of renal transplantation without immunosuppression as examples of situations described above.

Transplante renal sem imunossupressão de manutenção. Pares monozigóticos e receptores de rim e medula óssea do mesmo doador / Renal transplantation without maintenance immunosuppression. Identical twins and kidney transplantation following a successful bone marrow graft

Resumo Pacientes que receberam transplantes renais sem imunossupressão de manutenção têm sido esporadicamente relatados. Os casos incluem relatos de pacientes não aderentes que suspenderam a medicação imunossupressora, transplantes entre gêmeos monozigóticos, transplante renal após um bem sucedido transplante de medula óssea do mesmo doador e transplante simultâneo de medula óssea e rim para tratamento de pacientes com mieloma múltiplo com insuficiência renal associada. Existem, atualmente, ensaios clínicos em andamento com o propósito de induzir tolerância imunológica específica ao doador utilizando a infusão de células hematopoiéticas do mesmo doador do enxerto renal. A seguir, descrevemos dois casos de transplante renal sem imunossupressão como exemplos de situações descritas acima.

Abstract Renal transplantation without maintenance immunosuppression has been sporadically reported in the literature. The cases include non-adherent patients who discontinued their immunosuppressive medications, transplantation between identical twins, kidney transplantation after a successful bone marrow graft from the same donor and simultaneous bone marrow and kidney transplantation for the treatment of multiple myeloma with associated renal failure. There are also ongoing clinical trials designed to induce donor specific transplant tolerance with infusion of hematopoietic cells from the same kidney donor. Here we describe two cases of renal transplantation without immunosuppression as examples of situations described above.