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.

MO1016: Features of the Formation of Post-Infectious and Post-Vaccinal Humoral Immune Response to SARS-COV-2 in Kidney Recipients

BACKGROUND

This paper presents the results of studying the characteristics of the antibody response in kidney recipients who are at high risk of severe COVID-19.

METHOD

The study of features of the formation of post-infectious anti-SARS-CoV-2 IgG was carried out in the group of kidney recipients (n = 171) with PCR confirmed diagnosis of COVID-19. Studies of the characteristics of post-vaccination immunity were carried out in a group of vaccinated recipients (n = 49) with Sputnik V (Russia) or Vero Cell (China).

ELISA was used to detect IgG to S and N proteins of the SARS-CoV-2.

Comparative studies used a simple randomized selection of immunocompetent COVID-19 patients (n = 163).

Statistical data processing was carried out using the χ2 and Wald's methods.

RESULTS

It was found that 30 days after the onset of clinical symptoms of COVID-19 in kidney recipients, IgG to S and/or N proteins of SARS-CoV-2 were detected in 89.5% (83.9%–93.3%) of them. The detection rate of IgG to the S protein was higher than that to the N protein [87.7% (81.9%–91.9%) and 62.0% (54.5%–68.9%), respectively). At the same time, the seroprevalence to the pathogen varied by age: in the 18–34-year-old group it was 77.7% (59.9%–88.9%), in the 50–64-year-old group it was 96.7% (88.2%–99.8%) and in the group >64 years old it was 80.0% (66.8%–89.0%). This trend of antibody production in older recipients correlated with the highest frequency of registration in them of moderate and severe forms [66.7% (56.4%–75.6%)]. Differences due to the severity of the disease were noted both in the frequency of detectable antibodies [80.3% (69.5%–88.0%) in recipients with a mild form of COVID-19 and 96.0% in recipients with a severe form of infection (P < .001)] and in the intensity of the formed anti-SARS-CoV-2 immunity. Thus, high values of PC (positivity coefficient) (>12) to S protein were recorded in 52.7% (39.8%–65.3%) and 63.2% (53.1%–72.2%) patients with mild and severe forms of COVID-19, respectively, which indicated a direct dependence of the production of antiviral antibodies on the severity of the infection. It was found that in 62.6% (55.1%–69.5%) of recovered recipients anti-SARS-CoV-2 IgG persisted for a period of 3 months from the onset of infection. In a significant proportion of recipients [42.8% (35.5%–50.2%)], antibodies were detected for up to 15 months. In general, the post-infectious antibody response in kidney recipients and immunocompetent patients had similar patterns of development. Despite the general mechanism of antibody production, in immunocompetent patients, the frequency of detection of antiviral antibodies (to N protein: 82.9% and to S protein: 91.2%), tension indicators (high values of PC to N protein: 51.0% and to S protein: 75.5%) and the duration of retention (in 50.3% at 15 months of monitoring) were slightly higher than the same parameters in recipients with COVID-19.

In kidney recipients after immunization with Sputnik V and Vero Cell (n = 34), a rather low detection rate of antiviral IgG [52.9% (36.7%–68.6%) compared with a similar parameter (P < .001) in vaccinated immunocompetent individuals [96.8% (94.8%–98.1%)] was found. The seroprevalence in the group of recipients with hybrid immunity (after illness and vaccination, n = 15) was 86.7% (60.9%–97.5%). In a comparative analysis of the intensity of post-vaccination immunity, high values of PC to S protein (>12) were recorded in 44.0% (26.7%–62.9%) of recipients vaccinated with Sputnik V and 50.0% (31.4%–68.6%) of recipients vaccinated with Vero Cell. The inverse relationship was observed in immunocompetent individuals: 64.7% (58.1%–70.7%) for Sputnik V and 44.2% (36.8%–51.8%] for Vero Cell.

CONCLUSION

The patterns of antibody response to the causative agent in recipients with COVID-19 are comparable to those in immunocompetent patients, while for vaccinated recipients, a low frequency of detection of antiviral antibodies was shown, which indicates the need to continue research on the humoral immunity in people with vulnerable immunity in order to select the best tactics for COVID-19 immunization.

Metabolic syndrome in kidney transplant recipients with adverse cardiovascular events

Introduction

Kidney transplantation helps reduce cardiovascular mortality in patients receiving renal replacement therapy but the incidence of cardiovascular disorders in kidney transplant recipients remains significantly higher than in the general population. Metabolic syndrome is a combination of cardiovascular risk factors that can reinforce each other and increase the risk of cardiovascular disease and death in the general population.

Purpose

To study the incidence of the preceding metabolic syndrome in kidney transplant recipients with adverse cardiovascular events.

Methods

237 recipients six months after kidney transplantation were included in the study. 79 (33.3%) of them had adverse cardiovascular events during three years of observation. Other patients had no cardiovascular complications. The study groups were comparable by gender, age and traditional cardiovascular risk factors.

Results

The average waist circumference in kidney transplant recipients with adverse cardiovascular events was 98±14 cm, which was higher than in kidney transplant recipients without adverse cardiovascular events – 94±13 cm, p&lt;0.05.

The triglyceride level in the group of kidney transplant recipients with adverse cardiovascular events was 1.70 (1.30–2.50) mmol/L, which was higher than in kidney transplant recipients without cardiovascular complications – 1.45 (1.08–1.80) mmol/L, p&lt;0.01. Hypertriglyceridemia was more frequently diagnosed in recipients with adverse cardiovascular events – 44.3% (n=35) versus 27.8% (n=44), p&lt;0.05. In the study groups no statistically significant differences were found in the level of high-density lipoproteins and the incidence of their reduced level depending on the occurrence of adverse cardiovascular events – 1.30 (1.21–1.42) mmol/L and 20.3% (n=16) versus 1.31 (1.21–1.45) mmol/L and 8.4% (n=29).

The blood pressure level and the incidence of arterial hypertension was comparable in the study groups – 77.2% (n=61) and 69.6% (n=110).

Blood glucose levels and the incidence of hyperglycemia did not differ in the study groups, but post-transplant impaired glucose tolerance or post-transplant diabetes mellitus in recipients with adverse cardiovascular events were more common – 20.3% (n=16) versus 9.5% (n=15), p&lt;0.05.

So 41.8% (n=99) of the study patients had metabolic syndrome. The previous metabolic syndrome was more frequent in recipients with adverse cardiovascular events – 58.2% (n=46) versus 33.5% (n=53), p&lt;0.001.

Conclusion

Based on the study it was found that the metabolic syndrome increases the risk of adverse cardiovascular events in kidney transplant recipients. The main components of metabolic syndrome that have prognostic value in kidney transplant recipients were an increase in waist circumference, high blood triglyceride levels and the incidence of hypertriglyceridemia, a high incidence of post-transplant impaired glucose tolerance or post-transplant diabetes mellitus.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Belarusian State Medical UniversityMinsk Scientific and Practical Center of Surgery, Transplantology and Hematology

MO065DIAGNOSTIC CRITERIA OF HUMORAL REJECTION IN RENAL TRANSPLANT RECIPIENTS WITH PRE-EXISTING ANTI-HLA ANTIBODIES BASED ON SENTINEL SKIN FLAP BIOPSY

Background and Aims

Twenty years of transplantation of composite vascularised allografts have revealed the high immunogenicity of the constituent parts, especially the skin.Several researchers have proposed the use of vascular stalk flaps, which allow to performe skin biopsy and diagnose rejection without biopsy of the transplanted solid organ.Pre-existing anti-HLA antibodies represent a serious immunological barrier to successful kidney transplantation.We are not aware of any studies on the diagnosis of antibody-associated acute kidney allograft rejection from deceased donors in recipients with pre-existing antibodies, based on morphological examination of a sentinel skin flap on a vascular stalk.

The Aim: To determine the morphological features of humoral rejection in renal transplant recipients with pre-existing anti-HLA antibodies based on sentinel skin flap biopsy.

Method

Three skin-kidney allografts recipients underwent skin flap biopsy on 2nd day after transplantation. A kidney allograft biopsy was performed on day 7, 30, 60, 90.The results of morphological studies are presented using the Banff classification of renal allograft and skin allograft pathology. All recipients were female; 35, 44, and 57 years old. Two patients were re-transplanted and the main cause of CKD was chronic glomerulonephritis. The third patient, with congenital abnormality of the urinary tract, received her first graft.Pre-existing anti-HLA antibody levels before transplantation were 50%, 60%, 80%, respectively.

Results

All recipients showed signs of humoral rejection of the skin flap with thrombosis of the feeding vascular bundle, phlebitis, predominantly intimal arteritis with median necrosis, detachment and areactive necrosis of epidermis and epithelium of skin appendages. Clinical rejection, similar to the algorithm proposed by Etra J.W. et al. to assess preclinical skin rejection in an animal model (2019), was interpreted as G2 in two cases and G3 in one case. The Banff classification of the skin flap offers a qualitative assessment of certain biopsy parameters, while the kidney graft has qualitative-quantitative criteria for assessing rejection.

When comparing the two classifications, a quantitative gradation of pathological changes in the skin flap according to the parameter of intimal arteritis (v) and immunoreactivity of the C4d marker similar to renal rejection was possible. In histological examination of skin flap biopsies, the degree of vasculitis was assessed in a large feeding artery: in all three cases this parameter was equal to v3. C4d expression was analyzed in the endothelium of microcirculatory blood vessels of the dermis and hypodermis: C4d1 in one case and C4d3 in the other two. The analysis of renal allograft biopsies revealed signs of humoral rejection (v1) only at day 30 in two recipients whose C4d expression in the skin and hypodermis was strong (C4d3).

Conclusion

Antibody-mediated rejection of a vascularized sentinel skin flap in recipients with combined skin-kidney transplantation is characterized by vasculitis affecting a core vascular bundle in the form of endarteritis with necrosis of media,phlebitis and associated thrombosis.Further studies are required to determine the feasibility of using a vascular stalked skin flap in the diagnosis of humoral rejection after renal transplantation.

P1742POTENTIAL TREATMENT METHOD OF RECURRENT URINARY TRACT INFECTION IN POSTMENOPAUSAL KIDNEY TRANSPLANT RECIPIENTS: THE RESULTS OF PILOT STUDY

Background and Aims

Infectious complications remain a major cause of morbidity and mortality among transplant recipients. Urinary tract infection (UTI), especially recurrent UTI, is a common problem, with the prevalence up to 75% among kidney transplant (KTx) recipients. Older age, female gender and delayed graft function are among the independent risk factors for recurrent UTIs in renal transplant recipients*. Postmenopausal women with recurrent UTI after KTx especially caused by bacteria with multidrug antibiotic resistance (MDR) form a large and growing up group of patients with almost unachievable remission. The aim of the study was to assess the efficiency of different treatment schemes of recurrent UTI in postmenopausal female transplant recipients.

*prospective study presented at the 50th Interscience Conference on Antimicrobial Agents and Chemotherapy

Method

The randomized prospective pilot study was conducted to assess the efficiency of 3 different therapy schemes, study period: 2017-2019. Recurrent UTIs were defined as ≥2 UTIs in 6 months or ≥3 UTIs in 12 months. A UTI was diagnosed based upon the presence of pyuria defined as &gt;5 WBCs/high-power field and a urine culture of &gt;100,000 colonies/mL. All consecutive female patients with postmenopausal history who presented to the transplant clinic for follow-up over the study period of six months were prospectively randomized into 3 groups. The primary outcome was occurrence of UTI at 6 months.

Results

Escherichia coli was the responsible pathogen for recurrent UTI in 55% of cases. Other causative organisms include Klebsiella pneumoniae (35%) as well as Enterobacter spp (10%). The rate of resistance to all tested antibiotics was the highest in Klebsiella pneumoniae. The first episode of UTI occurred at 16 (8,5;42) week after KTx.

The total number of UTI episodes (per year) after treatment varies from 7 [5;8] in the 1st Group to 0 [0;0] at the 3rd Group (p&lt;0,001), in which 13 out of 15 patients achieved long-term remission during the observation period. Clinical data on the 1st check-up after treatment course and about UTI episodes are given bellow.

Conclusion

Frequent antibiotic usage often causes MDR as well as result in intestinal dysbacteriosis. Immunosuppression state, frequent antibiotic usage, intestinal disbiosis and also vaginal Ph decline form pathogenic vicious circle. Complex usage of fosfomycin that remains active against a considerable proportion of MDR gram-negative bacteria with bacteriophages, estrogen treatment and long-term probiotic supplement may reduce the UTI frequency in postmenopausal women after KTx.

P1703RESULTS OF RENAL TRANSPLANTATION IN PATIENTS WITH RHEUMATIC DISEASES

Background and Aims

Rheumatic diseases often involve the kidneys and it might lead to chronic kidney disease (CKD). In its final stage it must be treated with renal replacement methods such as dialysis (hemodialysis or peritoneal dialysis) or renal transplantation. Kidney transplantation is the preferred and most cost-effective treatment for the end-stage renal disease, it offers a better quality of life than dialysis. The most common types of renal pathology in rheumatic diseases include glomerular (systemic lupus erythematosus), vascular (ANCA-associated vasculitides) and tubulointerstitial (goat) diseases. According to a research conducted in 2010 at the Minsk Rheumatological Department, 25% of patients had clinical or laboratory features of CKD. The aims were to reveal the most frequent rheumatic diseases affecting the kidneys and evaluate the post-transplant period in these patients.

Method

94 medical case were studied retrospectively. All these patients had the end-stage renal disease with GFR of &lt;15 ml/min/1.73m2 and underwent renal transplantation between January 2011 and September 2019.

Results

A retrospective study of 94 kidney transplant patients was conducted on renal transplantation centers in Belarus. Among the patients that underwent renal transplantation from January 2011 till September 2019, the percentage of recipients with rheumatic diseases was 3.64%. The majority of the recipients (52 %) were females. The mean age was 44.36 years (range, 16-78 years). Of the sample, 90% of kidney allografts were received from brain-dead donors, whereas only 10% of recipients got a new kidney from living-donors. Systemic lupus erythematosus was the most common causative disease in patients with rheumatic diseases (31 cases, 33%) followed by goat (28 cases, 30%) and secondary amyloidosis (17 cases, 18%) that complicated the course of rheumatoid arthritis and seronegative spondylarthritis. The remaining part of patients suffered from ANCA-associated vasculitides (10 cases, 10.6%), anti-glomerular basement membrane disease (6 cases, 6.4%), and single cases were represented by progressive systemic sclerosis and antiphospholipid syndrome (2%). In the post-transplant period, the most common complications were arterial hypertension (38%), anemia (20%), infectious diseases (27%), among them the most frequent were urinary tract infection (20%) and cytomegalovirus infection (7%). The 1-year allograft survival rate was 86%, the 5-year rate was about 82%. The main reasons for failed outcomes were acute renal allograft rejection, postoperative complications and infection. The patient survival rate after 1 and 5 years after transplantation was 93% and 86%, respectively. Infectious diseases (44%) such as nosocomial pneumonia, sepsis and cardiovascular disease (33%) are still the two most important reasons of death.

Conclusion

1. The most common rheumatic diseases causing the end-stage renal disease are systemic lupus erythematosus (33%), goat (30%), rheumatoid arthritis, and seronegative spondylarthritis that lead to secondary amyloidosis (18%). 2. The 1-year allograft survival rate was 86%, the 5-year rate was about 82%, the patient survival rate after 1 and 5 years after transplantation was 93% and 86%, respectively. 3. The survival of patients with rheumatic diseases who underwent renal transplantation is comparable to patient survival after transplantation with another kidney pathology. 4. The main causes of death following renal transplantation are infectious and cardiovascular complications. Acute renal allograft rejection, postoperative complications, and infection are the main reasons of allograft failure.