A National Survey of Practice Patterns for Accepting Living Kidney Donors With Prior COVID-19.

INTRODUCTION: A critical question facing transplant programs is whether, when, and how to safely accept living kidney donors (LKDs) who have recovered from COVID-19 infection. The purpose of the study is to understand current practices related to accepting these LKDs. METHODS: We surveyed US transplant programs from 3 September through 3 November 2020. Center level and participant level responses were analyzed. RESULTS: A total of 174 respondents from 115 unique centers responded, representing 59% of US LKD programs and 72.4% of 2019 and 72.5% of 2020 LKD volume (Organ Procurement and Transplantation Network-OPTN 2021). In all, 48.6% of responding centers had received inquiries from such LKDs, whereas 44.3% were currently evaluating. A total of 98 donors were in the evaluation phase, whereas 27.8% centers had approved 42 such donors to proceed with donation. A total of 50.8% of participants preferred to wait >3 months, and 91% would wait at least 1 month from onset of infection to LD surgery. The most common reason to exclude LDs was evidence of COVID-19-related AKI (59.8%) even if resolved, followed by COVID-19-related pneumonia (28.7%) and hospitalization (21.3%). The most common concern in accepting such donors was kidney health postdonation (59.2%), followed by risk of transmission to the recipient (55.7%), donor perioperative pulmonary risk (41.4%), and donor pulmonary risk in the future (29.9%). CONCLUSION: Practice patterns for acceptance of COVID-19-recovered LKDs showed considerable variability. Ongoing research and consensus building are needed to guide optimal practices to ensure safety of accepting such donors. Long-term close follow-up of such donors is warranted.

Early Posttransplant Blood Transfusion and Risk for Worse Graft Outcomes.

INTRODUCTION: Blood transfusion is a risk factor for allosensitization. Nevertheless, blood transfusion posttransplant remains a common practice. We evaluated the effect of posttransplant blood transfusion on graft outcomes. METHODS: We included nonsensitized, first-time, kidney-alone recipients transplanted between 1 July 2015 and 31 December 2017. Patients were grouped based on receiving blood transfusion in the first 30 days posttransplant. The primary end point was a composite outcome of biopsy-proven acute rejection, death of any cause, or graft failure in the first year posttransplant. Secondary outcomes included the individual components of the primary outcome and the cumulative incidence of de novo donor-specific antibodies (DSAs). RESULTS: Two hundred seventy-three patients were included. One hundred twenty-seven (47%) received blood transfusion. Patients in the transfusion group were more likely to be older, have had a deceased donor, and have received induction with basiliximab. There was no difference between groups in the composite primary outcome (adjusted hazard ratio = [HR] 1.34; 95% confidence interval [CI], 0.83-2.17; P = 0.23). The cumulative incidence of de novo DSAs during the first year posttransplant was similar between groups (12.8% transfusion vs. 10.9% no transfusion, P = 0.48). CONCLUSION: Early transfusion of blood products in kidney transplant recipients receiving induction with lymphocyte depletion was not associated with an increased hazard of experiencing acute rejection, death from any cause, or graft loss.

The strength of donor-specific antibody is a more reliable predictor of antibody-mediated rejection than flow cytometry crossmatch analysis in desensitized kidney recipients.

The aim of this study was to evaluate the utility of donor-specific antibodies (DSA) and flow cytometry crossmatch (FCCM) as tools for predicting antibody-mediated rejection (AMR) in desensitized kidney recipients. Sera from 44 patients with DSA at the time of transplant were reviewed. Strength of DSA was determined by single antigen Luminex bead assay and expressed as mean fluorescence intensity (MFI). T- and B-cell FCCM results were expressed as mean channel shift (MCS). AMR was diagnosed by C4d deposition on biopsy. Incidence of early AMR was 31%. Significant differences in the number of DSAs (p = 0.0002), cumulative median MFI in DSA class I (p = 0.0004), and total (class I + class II) DSA (p < 0.0001) were found in patients with and without AMR. No significant difference was seen in MCS of T and B FCCM (p = 0.095 and p = 0.307, respectively). The three-yr graft survival in desensitized patients with DSA having total MFI < 9500 was 100% compared to 76% with those having total MFI > 9500 (p = 0.022). Desensitized kidney transplant recipients having higher levels of class I and total DSA MFI are at high risk for AMR and poor graft survival. Recipient DSA MFI appears to be a more reliable predictor of AMR than MCS of FCCM.

Pyrrolidine dithiocarbamate-zinc(II) and -copper(II) complexes induce apoptosis in tumor cells by inhibiting the proteasomal activity.

Zinc and copper are trace elements essential for proper folding, stabilization and catalytic activity of many metalloenzymes in living organisms. However, disturbed zinc and copper homeostasis is reported in many types of cancer. We have previously demonstrated that copper complexes induced proteasome inhibition and apoptosis in cultured human cancer cells. In the current study we hypothesized that zinc complexes could also inhibit the proteasomal chymotrypsin-like activity responsible for subsequent apoptosis induction. We first showed that zinc(II) chloride was able to inhibit the chymotrypsin-like activity of a purified 20S proteasome with an IC(50) value of 13.8 microM, which was less potent than copper(II) chloride (IC(50) 5.3 microM). We then compared the potencies of a pyrrolidine dithiocarbamate (PyDT)-zinc(II) complex and a PyDT-copper(II) complex to inhibit cellular proteasomal activity, suppress proliferation and induce apoptosis in various human breast and prostate cancer cell lines. Consistently, zinc complex was less potent than copper complex in inhibiting the proteasome and inducing apoptosis. Additionally, zinc and copper complexes appear to use somewhat different mechanisms to kill tumor cells. Zinc complexes were able to activate calpain-, but not caspase-3-dependent pathway, while copper complexes were able to induce activation of both proteases. Furthermore, the potencies of these PyDT-metal complexes depend on the nature of metals and also on the ratio of PyDT to the metal ion within the complex, which probably affects their stability and availability for interacting with and inhibiting the proteasome in tumor cells.