Advanced Tertiary Lymphoid Tissues in Protocol Biopsies are Associated with Progressive Graft Dysfunction in Kidney Transplant Recipients

Background: Tertiary lymphoid tissues (TLTs) are ectopic lymphoid tissues found in chronically inflamed organs. Although studies have documented TLT formation in transplanted kidneys, the clinical relevance of these TLTs remains controversial. We examined the impacts of TLTs on future graft function using our histological TLT maturity stages and the association between TLTs and Banff pathologic scores. We also analyzed the risk factors for the development of TLTs Methods: Serial protocol biopsy samples (0-hour, 1-, 6-, and 12-months) without rejection were retrospectively analyzed from 214 patients who underwent living donor kidney transplantation. TLTs were defined as lymphocyte aggregates with signs of proliferation and their stages were determined by the absence (stage I) or presence (stage II) of follicular dendritic cells. Results: Only 4% of patients exhibited TLTs at the 0-hour biopsy. Prevalence increased to almost 50% at the 1-month biopsy and then slightly further for 12 months. The proportion of advanced stage II TLTs increased gradually, reaching 19% at the 12-month biopsy. Presence of stage II TLTs was associated with higher risk of renal function decline after transplantation compared to patients with no TLT or stage I TLTs. Stage II TLTs were associated with more severe tubulitis and interstitial fibrosis/tubular atrophy at 12 months and predicted poorer graft function independently from the degree of interstitial inflammation. Pre-transplantation rituximab treatment dramatically attenuated the development of stage II TLTs. Conclusions: TLTs are commonly found in clinically stable transplanted kidneys. Advanced stage II TLTs are associated with progressive graft dysfunction, independent of interstitial inflammation

Proximal Tubule p53 in Cold Storage/Transplantation-Associated Kidney Injury and Renal Graft Dysfunction

Kidney injury associated with cold storage/transplantation is a primary factor for delayed graft function and poor outcome of renal transplants. p53 contributes to both ischemic and nephrotoxic kidney injury, but its involvement in kidney cold storage/transplantation is unclear. Here, we report that p53 in kidney proximal tubules plays a critical role in cold storage/transplantation kidney injury and inhibition of p53 can effectively improve the histology and function of transplanted kidneys. In a mouse kidney cold storage/transplantation model, we detected p53 accumulation in proximal tubules in a cold storage time-dependent manner, which correlated with tubular injury and cell death. Pifithrin-α, a pharmacologic p53 inhibitor, could reduce acute tubular injury, apoptosis and inflammation at 24 h after cold storage/transplantation. Similar effects were shown by the ablation of p53 from proximal tubule cells. Notably, pifithrin-α also ameliorated kidney injury and improved the function of transplanted kidneys in 6 days when it became the sole life-supporting kidney in recipient mice. in vitro, cold storage followed by rewarming induced cell death in cultured proximal tubule cells, which was accompanied by p53 activation and suppressed by pifithrin-α and dominant-negative p53. Together, these results support a pathogenic role of p53 in cold storage/transplantation kidney injury and demonstrate the therapeutic potential of p53 inhibitors.

Survival of Post-Transplant Lymphoproliferative Disorder after Kidney Transplantation in Patients under Rapamycin Treatment

Background: One of the important causes of mortality and morbidity in kidney transplanted patients is Post Transplant Lymphoproliferative Disease (PTLD), which is due to immunosuppression therapy and viral activity. It seems that Rapamycin, with dual antineoplastic and immunosuppressive effects, may have a pivotal role in the treatment of PTLD patients and preserving transplanted kidneys. Methods and Materials: Twenty patients with PTLD were enrolled. Immunosuppressive therapy was reduced or ceased, and Rapamycin was initiated at the time of PTLD diagnosis. We evaluated the effects of switching immunosuppressive drugs to Rapamycin on graft status, the response of tumor, and 6, 12 months, and 5-year survival in patients. Results: PTLD remission was achieved in 14 patients, while six patients died; no relapse was detected in recovered patients. The median of PTLD free time was 25 months, and the mean overall survival in patients with PTLD treated by Rapamycin was 84.8 (95% CI=61.3-108.23).The five-year survival rate was 67%, 12 months survival was 73.8%, and six months' survival was 80%. The response rate to Rapamycin and immunosuppression reduction alone was 46.6%. Four out of 13 Diffuse Large B-Cell Lymphoma patients achieved a complete response just only after the reduction of immunosuppressive drugs and the consumption of Rapamycin. Conclusion: The present study demonstrated the effectiveness of conversion from immunosuppressive medication, particularly of Calcineurin inhibitors to Rapamycin in PTLD patients. However, more research is needed to confirm the Rapamycin effect on patients with PTLD.

Assessment of Oxidative Stress Markers in Hypothermic Preservation of Transplanted Kidneys

Ischemia-reperfusion injury (IRI) after renal transplantation is a complex biochemical process. The first component is an ischemic phase during kidney storage. The second is reperfusion, the main source of oxidative stress. This study aimed to analyze the activity of enzymes and concentrations of non-enzymatic compounds involved in the antioxidant defense mechanisms: glutathione (GSH), glutathione peroxidase (GPX), catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GR), glutathione transferase (GST), thiobarbituric acid reactive substances (TBARS), malondialdehyde (MDA), measured in preservation fluid before transplantation of human kidneys (KTx) grafted from brain dead donors. The study group (N = 66) was divided according to the method of kidney storage: Group 1—hypothermic machine perfusion (HMP) in LifePort perfusion pump, n1 = 26, and Group 2—static cold storage (SCS), n2 = 40. The measurements of kidney function parameters, blood count, and adverse events were performed at constant time points during 7-day hospitalization and 3-month follow-up. Kidney perfusate in Group 2 was characterized by significantly more acidic pH (p < 0.0001), higher activity of GPX [U/mgHb] (p < 0.05) and higher concentration of MDA [μmol/L] (p < 0.05). There was a statistically significant improvement of kidney function and specific blood count alterations concerning storage method in repeated measures. There were aggregations of significant correlations (p < 0.05) between kidney function parameters after KTx and oxidative stress markers: diuresis & CAT, Na+ & CAT, K+ & GPX, urea & GR. There were aggregations of significant correlations (p < 0.05) between recipient blood count and oxidative stress markers: CAT & MON, SOD & WBC, SOD & MON. Study groups demonstrated differences concerning the method of kidney storage. A significant role of recipient’s gender, gender matching, preservation solution, and perfusate pH was not confirmed, however, basing on analyzed data, the well-established long-term beneficial impact of HMP on the outcome of transplanted kidneys might partially depend on the intensity of IRI ischemic phase and oxidative stress, reflected by the examined biomarkers.

The stiffness of transplanted kidneys changes with time after renal transplantation

Background Kidney transplantation is one of the most effective ways to treat end-stage kidney disease. However, 5000 renal transplant recipients start or restart dialysis because of chronic allograft nephropathy (CAN) every year in the United States. Detecting changes in the stiffness of transplanted kidneys can help diagnose transplanted kidney disease. Purpose To explore changes in the stiffness of transplanted kidneys after renal transplantation using shear wave elastography (SWE). Material and Methods This study conducted consecutive follow-up observations on 10 patients after kidney transplantation. SWE examination was performed in the first week, second week, first month, second month, third month, fourth month, fifth month, and sixth month after surgery. This study also analyzed the graft stiffness of 86 patients with stable renal function recovery one month after surgery. Results The results show that there is a change in the stiffness of the transplanted kidney over time after renal transplantation. It decreases rapidly within one month after renal transplantation and tends to be stable after one month. The mean renal cortical and pyramidal stiffness of patients with stable renal function were 28.48 ± 4.27 kPa and 21.97 ± 3.90 kPa, respectively. Conclusion Consecutive stiffness measurement of transplanted kidneys is an effective method for monitoring the function of transplanted kidneys. According to the change in transplanted kidney stiffness, we can designate a more scientific review plan to determine the functional status of the transplanted kidney.

A kadáverdonor-vesék elfogadási gyakorlatának vizsgálata a debreceni transzplantációs centrumban

Összefoglaló. Bevezetés: A magyarországi vesetranszplantáció 2013 óta az Eurotransplant (ET) keretein belül zajlik. A debreceni vesetranszplantációs centrumhoz évente kb. 200 kadáverdonorvese-felajánlás érkezik, melyek 37%-a kerül a megismert adatok alapján elfogadásra. Nem minden elfogadott vese kerül beültetésre, aminek számos oka lehet. Célkitűzés: A debreceni szakmai gyakorlat elemzése és bemutatása reprezentatív mintán. Módszer: A debreceni centrumhoz 2016. november és 2020. március között 624 vesefelajánlás érkezett. A felajánlott vesék 37%-a (n = 229) került előzetesen elfogadásra, később az elfogadott vesék 63%-a (n = 144) került beültetésre. Centrumunkban az ún. ’standard criteria’, azaz tökéletes minőségű donorvesék szignifikánsan magasabb arányban kerültek elfogadásra, majd beültetésre, mint az ’extended criteria’, azaz kompromisszummal vállalhatók. Az elfogadott és nem elfogadott veséket vizsgálva a KDPI (kidney donor profile index) és a KDRI (kidney donor risk index) értéke szignifikánsan magasabb volt az elutasított donorok esetében (p<0,001). Eredmények: Elemeztük, hogy a felajánlott, de a centrum által nem beültetett donorveséket más ET-centrumban elfogadták-e. Látható, hogy a felajánlott 624 donorvese közül 144 Debrecenben, 313 pedig más ET-centrumban került beültetésre, viszont 167 vese beültetése egyik ET-centrumban sem történt meg (discarded organ). A 36–85 KDPI-értékkel rendelkező csoportból került beültetésre a legtöbb donorvese (180 vese) más ET-centrumban. A Debrecenben beültetett kadáverdonor-vesék KDPI- és KDRI-értéke szignifikánsan alacsonyabb volt a nekünk felajánlott, majd máshol beültetett vesékhez képest. Következtetés: Összességében elmondható, hogy a debreceni centrumban a magas rizikócsoportba tartozó donorszervek elutasításra kerültek, miközben más centrumban a nagy részüket beültették. Ez alapján a 36–85 KDPI-értékű csoport a transzplantációs esetszám bővítésének lehetséges forrása a recipiens ismeretében. Orv Hetil. 2021; 162(26): 1022–1028. Summary. Introduction: Kidney transplantation in Hungary is carried out via Eurotransplant (ET). Our centre in Debrecen receives around 200 kidney offers a year, of which 37% are accepted. Not all accepted kidneys are transplanted, which can be a result of a number of causes. Obejctive: A debreceni szakmai gyakorlat elemzése és bemutatása reprezentatív mintán. Method: Between November 2016 and March 2020, the centre of Debrecen received 624 kidney offers. 37% (n = 229) of the offered kidneys got preliminarily accepted, of which 63% (n = 144) were transplanted later. In our centre, standard criteria donor kidneys were accepted and transplanted in significantly higher rate, than extended criteria donor kidneys. Looking at accepted and rejected kidneys, KDPI and KDRI values were significantly higher in the case of the refused ones (p<0.001). Results: Part of our assessment is to analyze whether kidneys offered to and refused by us got accepted in other transplant centres. In the examined period, of the 624 kidneys offered to our centre 144 were transplanted in Debrecen, 313 were transplanted in other ET centres, while 167 were not transplanted at all (discarded organ). The majority of transplanted kidneys in other ET centres had KDPI values between 36 and 85 (180 kidneys.) KDPI and KDRI values of kidneys transplanted in our centre were significantly lower than those that were offered to us, but got transplanted elsewhere. Conclusion: To summarize, we can say that high-risk donor organs are refused in the transplant centre of Debrecen, while the majority of them are being transplanted in other centres. Based on this, kidneys of KDPI value between 36 and 85 are a possible source of expanding the number of transplantations, with regards to the recipient. Orv Hetil. 2021; 162(26): 1022–1028.

Clinical outcomes associated with long-term exposure to airborne particulate pollution in kidney transplant recipients

Background Researchers have yet to investigate the specific association between 10-μm particulate matter (PM10) levels and the risk of graft failure, kidney disease, or the functional decline of transplanted kidneys, in kidney transplant recipients (KTRs). Furthermore, we know very little about the association between PM10 levels and the development of allograft rejection in transplanted kidneys. Identification of air pollution as a potential contributor to kidney disease could help reduce future disease burden, stimulate policy discussions on the importance of reducing air pollution with respect to health and disease, and increase public awareness of the hazards of air pollution. We aimed to evaluate the relationship of PM10 with the risk of graft failure, mortality, and decline of graft function in KTRs. Methods Air pollutant data were obtained from the Korean National Institute of Environmental Research. We then investigated potential associations between these data and the clinical outcomes of 1532 KTRs who underwent kidney transplantation in a tertiary hospital between 2001 and 2015. Survival models were used to evaluate the association between PM10 concentrations and the risk of death-censored graft failure (DCGF), all-cause mortality, and biopsy-proven rejection (BPR), over a median follow-up period of 6.31 years. Results The annual mean PM10 exposure after kidney transplantation was 27.1 ± 8.0 μg/m3. Based on 1-year baseline exposure, 1 μg/m3 increase in PM10 concentration was associated with an increased risk of DCGF (hazard ratio (HR): 1.049; 95% confidence interval (CI): 1.014–1.084) and BPR (HR: 1.053; 95% CI: 1.042–1.063). Fully adjusted models showed that all-cause mortality was significantly associated with 1-year average PM10 concentrations (HR, 1.09; 95% CI, 1.043 to 1.140). Conclusions Long-term PM10 exposure is significantly associated with BPR, DCGF, and all-cause mortality in KTRs.