The ERA Registry Annual Report 2021: a summary

Background

The European Renal Association (ERA) Registry collects data on kidney replacement therapy (KRT) in patients with end-stage kidney disease (ESKD). This paper is a summary of the ERA Registry Annual Report 2021, including a comparison across treatment modalities.

Methods

Data was collected from 54 national and regional registries from 36 countries, of which 35 registries from 18 countries contributed individual patient data and 19 registries from 19 countries contributed aggregated data. Using this data, incidence and prevalence of KRT, kidney transplantation rates, survival probabilities and expected remaining lifetimes were calculated.

Result

In 2021, 533.2 million people in the general population were covered by the ERA Registry. The incidence of KRT was 145 per million population (pmp). In incident patients, 55% were 65 years or older, 64% were male, and the most common primary renal disease (PRD) was diabetes (22%). The prevalence of KRT was 1040 pmp. In prevalent patients, 47% were 65 years or older, 62% were male, and the most common PRDs were diabetes and glomerulonephritis/sclerosis (both 16%). On 31 December 2021, 56% of patients received haemodialysis, 5% received peritoneal dialysis, and 39% were living with a functioning graft. The kidney transplantation rate in 2021 was 37 pmp, a majority coming from deceased donors (66%). For patients initiating KRT between 2012-2016, 5-year survival probability was 52%. Compared to the general population, life expectancy was 65% and 68% shorter for males and females receiving dialysis, and 40% and 43% shorter for males and females living with a functioning graft.

Factors influencing kidney transplantation rates: a study from the ERA Registry

BACKGROUND

Large international differences exist in kidney transplantation (KT) rates. We aimed to investigate which factors may explain the total, deceased donor, and living donor KT rates over the last decade.

METHODS

KT experts from 39 European countries completed the Kidney Transplantation Rate Survey on measures and barriers and their potential effect on the KT rate in their country. In the analyses, countries were divided into low, middle, and high KT rate countries based on the KT rate at the start of study period in 2010.

RESULTS

Experts from low KT rate countries reported more frequently to have taken measures regarding staff, equipment and facilities to increase total KT rate compared with middle and high KT rate countries. For donor type specific KT, the largest international differences in measures taken were reported for deceased donor KT, with middle and high KT rate countries taking more measures, such as the use of expanded criteria donor kidneys, the presence of transplantation coordinators, and (inter)national exchange of donor kidneys. Once a measure was taken, experts' opinion on its success was similar across the low, middle and high KT rate countries. Experts from low KT rate countries more often reported potential barriers, such as patients' lack of knowledge and distrust in the health care system.

CONCLUSIONS

In particular in low KT rate countries, KT rate might be stimulated by optimizing staff, equipment, and facilities. In addition, all countries may benefit from deceased and living donor specific measures.

Trends in kidney transplantation rate across Europe: Study from the ERA Registry

BACKGROUND

The aim of this study was to identify trends in total, deceased donor and living donor kidney transplantation (KT) rates in European countries.

METHODS

The European Renal Association (ERA) Registry and the Global Observatory on Donation and Transplantation (GODT) databases were used to obtain the number of KTs in individual European countries between 2010 and 2018. General population counts were obtained from Eurostat or the national bureaus of statistics. The KT rate per million population (pmp) and the average annual percentage change (APC) were calculated.

RESULTS

The total KT rate in the 40 participating countries increased with 1.9% annually (95% confidence interval (CI): 1.5, 2.2) from 29.6 pmp in 2010 to 34.7 pmp in 2018, reflecting an increase of 3.4 pmp in the deceased donor KT rate (from 21.6 pmp to 25.0 pmp, APC: 1.9% [95%CI: 1.3, 2.4]) and of 1.5 pmp in the living donor KT rate (from 8.1 pmp to 9.6 pmp, APC: 1.6% [95%CI: 1.0, 2.3]). The trends in KT rate varied widely across European countries. An East-West gradient was observed for deceased donor KT rate with Western European countries performing more KTs. In addition, most countries performed less living donor KTs. In 2018, Spain had the highest deceased donor KT rate (64.6 pmp) and Turkey the highest living donor KT rate (37.0 pmp).

CONCLUSIONS

The total KT rate increased due to a rise in the KT rate from deceased donors and to a lesser extent from living donors, with large differences between individual European countries.

Leucine-Rich Alpha-2-Glycoprotein (LRG-1) as a Potential Kidney Injury Marker in Kidney Transplant Recipients

Background

Kidney transplantation is the treatment of choice for most patients with end-stage renal disease. To improve patient and transplant survival, non-invasive diagnostic methods for different pathologies are important. Leucine-rich alpha-2-glycoprotein (LRG-1) is an innovative biomarker that is elevated in cases of angiogenesis, inflammation, and kidney injury. However, there are limited data about the diagnostic role of LRG-1 in kidney transplant recipients. The aim of this study was to evaluate the association between serum LRG-1, urine LRG-1, and kidney transplant function and injury.

Material/Methods

We enrolled 35 kidney transplant recipients in the study. LRG-1 in the serum and urine was detected using ELISA. We evaluated the correlation of serum and urine LRG-1 with traditional serum and urine kidney injury markers.

Results

A higher level of serum LRG-1 correlates with a higher level of urine LRG-1. Serum LRG-1 has a positive correlation with transplant age, serum urea, serum creatinine, serum cystatin C, proteinuria, and fractional excretion of sodium (FENa) and a negative correlation with hemoglobin and estimated glomerular filtration rate (eGFR). Urine LRG-1 has a positive correlation with serum cystatin C, proteinuria, and urine neutrophil gelatinase-associated lipocalin (NGAL).

Conclusions

Higher levels of serum and urine LRG-1 are associated with kidney transplant injury and functional deterioration. Thus, LRG-1 might be also as a biomarker for tubular dysfunction in patients after kidney transplantation.

MO945SERUM AND URINE LEUCINE RICH ALPHA-2-GLYCOPROTEIN-1 IS ASSOCIATED WITH KIDNEY TRANSPLANT INJURY AND FAILURE

Background and Aims

Kidney transplantation is the treatment of choice for most of the patients with end stage chronic kidney disease. To improve patient and graft survival, early diagnostics and discovery of specific biomarkers is important. Leucine rich alpha-2-glycoprotein-1 (LRG-1) is an innovative, non-invasive biomarker that is elevated in case of angiogenesis, inflammation and kidney injury. Aim was to evaluate biomarker LRG-1 level in serum and urine in kidney transplant recipients in accordance with kidney injury markers and time period after kidney transplantation.

Method

In the study 35 patients were enrolled. Patients had functioning kidney grafts and they were more than one year post transplant. We detected patient serum and urine LRG-1 levels, using ELISA. Correlation between serum LRG-1, urine LRG-1 and kidney graft structural and functional damage markers was performed. Also, we compared serum LRG-1 levels between subgroups (patients >5 years post transplant and ≤ 5 years post transplant).

Results

Serum LRG-1 had positive correlation with serum cystatin-C (r=0,46, p<0,01), serum urea (r=0,53, p<0,01) and negative correlation with eGFR (r= -0,39, p=0,02). Patients with >5 years post transplant had higher serum LRG-1 level compared with patients ≤5 years post transplant (p<0,01). Serum LRG-1 had positive correlation with a longer time period after transplantation (r=0,53, p=0,01). Urine LRG-1 had correlation with proteinuria (r=0,58, p<0,01) and NGAL level in urine (r=0,44, p<0,01). The most common maintenance immunosuppressive regimen was therapy with tacrolimus, mycophenolate and prednisolone (48,6%).

Conclusion

Higher serum LRG-1 level correlates with decreased kidney transplant function and with longer time period after transplantation. Higher LRG-1 level in serum and urine is related to kidney transplant injury and failure. Urine LRG-1 can be a useful biomarker for tubular dysfunction in kidney transplant recipients.

Influence of Pretransplant Dialysis Vintage on Repeated Kidney Transplantation Outcomes

Dialysis has a dose-dependent effect on first kidney transplantation outcomes, and a shorter waiting time on dialysis is associated with superior graft function. There are not enough data to support this statement in the case of a repeated transplantation. As such, we aimed to evaluate the influence of the dialysis vintage before the last transplantation on graft function as well as patient and graft survival in repeated transplantation situations. Patients who underwent repeated kidney transplantations were included in the retrospective study. Specifically, 79 patients were included who were divided into 4 groups according to the dialysis vintage before the last transplantation. We assessed graft function and patient and graft survival rates after 1- and 3-year follow-up. One-year graft function was worse for patients with a dialysis vintage of more than 31 months (P = .005), but there was no difference after 3 years. One- and 3-year graft survival was better for patients with a dialysis vintage of less than 12 months (P = .017). We concluded that a longer waiting time on dialysis was associated with worse graft function and diminished long-term graft survival after repeated kidney transplantation.

Human papillomavirus type 18 infection in a female renal allograft recipient: a case report

BACKGROUND

Human papillomavirus type 18 is the second most common cause of cervical cancer and is found in 7 to 20 % of cases of cervical cancer. The oncogenic potential of high-risk human papillomavirus is associated with expression of early proteins E6 and E7. Due to long-term immunosuppressive therapy, renal transplant recipients have a higher risk of developing persistent human papillomavirus infection.

CASE PRESENTATION

A 29-year-old white woman from Latvia with chronic focal segmental glomerulosclerosis received renal allograft transplantation and was prescribed immunosuppressive therapy with cyclosporine, prednisolone, and mycophenolate mofetil. Two weeks after renal transplantation, her cervical swab was positive for human papillomavirus consensus sequences. After 6 months, quantitative polymerase chain reaction showed a high viral load of 3,630,789 copies/10⁵ cells of high-risk human papillomavirus type 18 and expression of E6 and E7 oncogenes in her cervical swab and urine sample. One year after renal transplantation, the viral load in her cervical swab increased significantly to 7,413,102 copies/10⁵ cells. Messenger ribonucleic acid of human papillomavirus type 18 E6 and E7 oncogenes were also detected. Shortly after this, she had an unsuccessful pregnancy which resulted in a spontaneous abortion at 6/7 weeks. Two months after the abortion her viral load sharply decreased to 39 copies/10⁵ cells. Oncogenes E6 and E7 messenger ribonucleic acid expression was not observed in this period.

CONCLUSIONS

This case report represents data which show that immunosuppressive therapy may increase the risk of developing persistent high-risk human papillomavirus infection with expression of E6 and E7 oncogenes in renal transplant recipients. However, even during this therapy the immune status of a recipient can improve and contribute to human papillomavirus viral load reduction. Spontaneous abortion can be considered a possible contributory factor in human papillomavirus clearance.

Reactivation of BK Virus in the Early Period After Kidney Transplantation

BACKGROUND

Typically, polyoma BK virus (BKV) remains latent in the urogenital tract after primary infection. Reactivation of BKV in recipients of kidney allografts can cause progressive graft dysfunction known as BK virus nephropathy (BKVN). The cornerstone of treatment for BKVN is prevention; therefore, it is important to detect BKV reactivation early and reduce immunosuppression. We sought to identify the BKV reactivation rate and associated factors in a prospective study.

MATERIALS AND METHODS

We studied 37 consecutive unselected adult recipients who underwent deceased donor kidney transplantation in 2007 and completed at least 3 months of observation. Qualitative nested polymerase chain reaction (PCR) testing was performed to detect BKV DNA in urine and plasma specimens.

RESULTS

In all cases, BK viremia or viruria was not detected on the postoperative day or 2 weeks thereafter. At 3 months, BKV reactivation developed in 6 (16%) of 37 recipients. Simultaneous viremia and viruria were present on 5 patients and viremia only in 1 patient. Significant risk factors for BK viremia were body mass index >30 kg/m(2) (P = .02), retransplantation (P =.04), and use of tacrolimus (P = .02). Serum creatinine values at 3 months after transplantation were significantly higher among patients with active BKV infection (P = .008).

CONCLUSIONS

Early BKV reactivation is associated with worse graft function as early as 3 months after transplantation. Obesity, retransplantation, and use of tacrolimus were factors promoting early development of BKV viremia.