The TreaT-Assay: A Novel Urine-Derived Donor Kidney Cell-Based Assay for Prediction of Kidney Transplantation Outcome

Abstract

Donor-reactive immunity plays a major role in rejection after kidney transplantation, but analysis of donor-reactive T-cells is not applied routinely. However, it has been shown that this could help to identify patients at risk of acute rejection. A major obstacle is the limited quantity or quality of the required allogenic stimulator cells, including a limited availability of donor-splenocytes or an insufficient HLA-matching with HLA-bank cells. To overcome these limitations, we developed a novel assay, termed the TreaT (Transplant reactive T-cells)-assay. We cultivated renal tubular epithelial cells from the urine of kidney transplant patients and used them as stimulators for donor-reactive T-cells, which we analyzed by flow cytometry. We could demonstrate that using the TreaT-assay the quantification and characterization of alloreactive T-cells is superior to other stimulators. In a pilot study, the number of pre-transplant alloreactive T-cells negatively correlated with the post-transplant eGFR. Frequencies of pre-transplant CD161+ alloreactive CD4+ T-cells and granzyme B producing alloreactive CD8+ T-cells were substantially higher in patients with early acute rejection compared to patients without complications. In conclusion, we established a novel assay for the assessment of donor-reactive memory T-cells based on kidney cells with the potential to predict early acute rejection and post-transplant eGFR.

Immune monitoring facilitates the clinical decision in multifocal COVID-19 of a pancreas-kidney transplant patient

“…In addition, the role of cytotoxic CD4+T cells for the SARS‐CoV‐2 clearance as shown by our and other groups for other viruses is also not clear 15 . Few data on SARS‐CoV‐2 reactive T cells have been published so far regarding nonimmunosuppressed patient cohorts 16‐20 . Data on SARS‐CoV‐2 reactive cellular immunity in immunosuppressive patients are lacking.…”

Donor HLA genotyping of ex vivo expanded urine cells from kidney transplant recipients

“…Recently, urine-derived cells harvested within the first week after kidney transplantation were used to stimulate donorreactive T cells in order to predict early acute rejection. 28 The combination of the urine-derived cell expansion technique with post-transplantation immune monitoring tools opens opportunities for lifelong, individualized immune risk assessment for kidney transplant recipients.…”

A noninvasive diagnostic approach to retrospective donor HLA typing in kidney transplant patients using urine

“…The biopsy cylinder was immediately stored at À80 °C and DNA was extracted subsequently. Another option was expanding donor tubular cells from the recipients' urine as described earlier [15,16]. Human urinary Primary Tubular Cells (huPTC) were cultured over a period of 3 weeks, with two passages until a confluent 10 cm 2 culture dish was available for DNA extraction (Fig.…”

“…We have recently applied this technique to clarify the genetic background of a kidney donor more than ten years after her death [15]. Very recently another group has used this technique to introduce an interesting method of co‐culturing donor tubular cells with recipient´s T cells to monitor allogenic responses [16]. Our study introduces this procedure as a reliable method to retrospectively perform donor HLA typing wherever and whenever necessary.…”