The prevalence and predictive factors of urinary tract infection in patients undergoing renal transplantation: A meta-analysis

Diagnosing and Managing Urinary Tract Infections in Kidney Transplant Recipients

In the article, the authors review antibiotic treatment options for both acute uncomplicated UTI and complicated UTI. In addition, they review alternative regimens which are needed in the setting of drug-resistant pathogens including vancomycin-resistant Enterococcus, -extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E), carbapenem-resistant Enterobacterales, and carbapenem-resistant Pseudomonas, which are encountered with more frequency.

Recipient donor sex combinations in solid organ transplantation and impact on clinical outcome: A scoping review

INTRODUCTION

Solid organ transplantation (SOT) is a lifesaving treatment for end-stage organ failure. Although many factors affect the success of organ transplantation, recipient and donor sex are important biological factors influencing transplant outcome. However, the impact of the four possible recipient and donor sex combinations (RDSC) on transplant outcome remains largely unclear.

METHODS

A scoping review was carried out focusing on studies examining the association between RDSC and outcomes (mortality, graft rejection, and infection) after heart, lung, liver, and kidney transplantation. All studies up to February 2023 were included.

RESULTS

Multiple studies published between 1998 and 2022 show that RDSC is an important factor affecting the outcome after organ transplantation. Male recipients of SOT have a higher risk of mortality and graft failure than female recipients. Differences regarding the causes of death are observed. Female recipients on the other hand are more susceptible to infections after SOT.

CONCLUSION

Differences in underlying illnesses as well as age, immunosuppressive therapy and underlying biological mechanisms among male and female SOT recipients affect the post-transplant outcome. However, the precise mechanisms influencing the interaction between RDSC and post-transplant outcome remain largely unclear. A better understanding of how to identify and modulate these factors may improve outcome, which is particularly important in light of the worldwide organ shortage. An analysis for differences of etiology and causes of graft loss or mortality, respectively, is warranted across the RDSC groups.

PRACTITIONER POINTS

Recipient and donor sex combinations affect outcome after solid organ transplantation. While female recipients are more susceptible to infections after solid organ transplantation, they have higher overall survival following SOT, with causes of death differing from male recipients. Sex-differences should be taken into account in the post-transplant management.

Effect of increasing age and ureteral stent implantation on urinary tract infections after kidney transplantation - update of recent literature

PURPOSE OF REVIEW

This review aims to present the recent literature regarding effects of aging and ureteral stent implantation (UrS) on the risk of urinary tract infections (UTIs) in kidney transplant (KTX) recipients.

RECENT FINDINGS

UTIs in kidney transplant recipients remain a clinical challenge and represent a leading cause of morbidity, hospitalization rates, and mortality. Higher age was described as a significant risk factor for UTIs in several studies including a recent Brazilian analysis, indicating a 3.6%/years of age increase in UTI risk. Subsequently, a large meta-analysis, published in 2023, confirmed the correlation between older age and elevated UTI risk. The Swiss Transplant Cohort Study in 2022, largest of its kind, similarly confirmed a link between advanced age and heightened risk of recurrent UTIs in KTX. A recent prospective study highlighted UrS placement as a modifiable risk factor, emphasizing the need for careful consideration and antibiotic prophylaxis. Additionally, the type of stents played a crucial role, with external stents associated with a 1.69 times higher UTI risk. The challenge of determining optimal UrS removal timing further complicates posttransplant care, with insufficient evidence to guide practices.

SUMMARY

The aging population of KTX recipients requires a personalized approach to effectively reduce and manage UTIs as one of the most important complications following KTX. Prophylactic stent implantation is successful in lowering ureteral complications, however, is associated with an increased incidence of UTIs. To reduce the increased risk of UTIs, the length of stent insertion requires strict supervision and maintenance.

Influence of diabetes and other risk factors on in-hospital mortality following kidney transplantation: an analysis of the Spanish National Hospital Discharge Database from 2016 to 2020

INTRODUCTION

To assess time trends in incidence, clinical characteristics, complications, and hospital outcomes among patients with type 1 diabetes (T1D), with type 2 diabetes (T2D), and patients without diabetes who underwent kidney transplant (KT); to identify variables associated with in-hospital mortality (IHM); and to determine the impact of the COVID-19 pandemic.

RESEARCH DESIGN AND METHODS

We used a nationwide discharge database to select KT recipients admitted to Spanish hospitals from 2016 to 2020. We stratified patients according to diabetes status. We used multivariable logistic regression to identify the variables associated with IHM.

RESULTS

A total of 14 594 KTs were performed in Spain (T2D, 22.28%; T1D, 3.72%). The number of KTs rose between 2016 and 2019 and and decreased from 2019 to 2020 in all groups. In patients with T2D, the frequency of KT complications increased from 21.08% in 2016 to 34.17% in 2020 (p<0.001). Patients with T2D had significantly more comorbidity than patients with T1D and patients without diabetes (p<0.001). Patients with T1D experienced KT rejection significantly more frequently (8.09%) than patients with T2D (5.57%).COVID-19 was recorded in 26 out of the 2444 KTs performed in 2020, being found in 6 of the 39 patients deceased that year (15.38%) and in 0.83% of the survivors.The variables associated with IHM were comorbidity and complications of KT. The presence of T1D was associated with IHM (OR 2.6; 95% CI 1.36 to 5.16) when patients without diabetes were the reference category. However, T2D was not associated with a higher IHM (OR 0.86; 95% CI 0.61 to 1.2).

CONCLUSIONS

The COVID-19 pandemic led to a decrease in the number of transplants. Patients with T1D have more rejection of the transplanted organ than patients with T2D. Fewer women with T2D undergo KT. The presence of T1D is a risk factor for IHM.

Molecular characterization of ESBL-producing uropathogenic Escherichia coli isolates among kidney transplant patients: Emergence and spread of B2-ST131 clone type

This study was conducted to identify the distribution of virulence determinants in uropathogenic Escherichia coli (UPEC) isolates obtained from kidney transplant (KTP) and non-transplant patients (non-KTP) with urinary tract infections (UTI). Additionally, the (GTG)5 fingerprinting technique was used to investigate the genetic diversity of Extended-Spectrum B-Lactamase (ESBL)-positive isolates. In this case-control study, 111 urine isolates were obtained from non-KTPs and KTPs, respectively. The presence of genetic markers encoding adhesion proteins, toxins and major E. coli phylogroups was assessed through PCR amplification. Molecular typing of ESBL-positive UPEC strains was performed using (GTG)5 fingerprinting and Multilocus sequence typing (MLST) techniques. Overall, 65 and 46 UPEC isolates were obtained from non-KTPs and KTPs, respectively. Among the studied isolates, traT (85.6%) gene was the most frequently observed virulence gene, followed by kpsMT (49.5%). Using the 80% cut-off point, all the 35 UPEC isolates were classified into four major clusters, namely A, B, C, and D. The majority of the Sequence Type (ST) 131 isolates belonged to cluster A. Additionally, three ST1193 isolates belonged to cluster A and phylogroup B2. Moreover, ST38, ST131 and ST10 were in different cluster. In general, we observed significant differences in the papA, ompT, sat, and vat genes between KTPs and non-KTPs. Furthermore, since all the isolates carried one or more virulence factors (VFs), these findings are concerning in the context of managing UTIs caused by the UPEC strain. Additionally, the distribution of ST and Clonal Complex (CC) among isolates in the main clusters revealed significant differences between MLST and (GTG)5 fingerprinting analysis.

Urine microbiome in individuals with an impaired immune system

With the advent of next generation sequencing, it is now appreciated that human urine is not sterile. Recent investigations of the urinary microbiome (urobiome) have provided insights into several urological diseases. Urobiome dysbiosis, defined as non-optimal urine microbiome composition, has been observed in many disorders; however, it is not clear whether this dysbiosis is the cause of urinary tract disorders or a consequence. In addition, immunologically altered disorders are associated with higher rates of urinary tract infections. These disorders include immunoproliferative and immunodeficiency diseases, cancer, and immunosuppressant therapy in transplant recipients. In this review, we examine the current state of knowledge of the urobiome in immunologically altered diseases, its composition and metabolomic consequences. We conclude that more data are required to describe the urobiome in immune altered states, knowledge that could facilitate understanding the role of the urobiome and its pathophysiological effects on urinary tract infections and other disorders of the urinary tract.

Prevalence and risk factors of urinary tract infection in kidney recipients: a meta-analysis study

BACKGROUND

A kidney recipient's urinary tract infection (UTI) can result in infectious problems and be a risk factor for less successful transplant outcomes. UTI risk factors are still controversial. The present study aimed to investigate the prevalence of UTI and its association with risk factors in kidney recipients.

METHOD

Twenty-six papers published between 2005 and 2022 were retrieved using keywords and searching Medlib, ScienceDirect, PubMed, and other databases. If possible, the pooled prevalence of UTI in kidney recipients and odds ratio (OR) with a 95% confidence interval for each risk factor were calculated. The data were analyzed using the random effects model in R and Stata 14.

RESULTS

The total sample size was 72,600, with an average age of 48.7 years. The pooled prevalence of UTI was 35% (95% CI, 30-40%). The estimated risk factors for UTI were female (OR = 3.13; 95%CI: 2.35-4.17), older age (OR = 1.03; 95%CI: 1-1.05), history of UTI (OR = 1.31; 95%CI) CI: 1.05-1.63), receiving a kidney from a deceased donor (OR = 1.59; 95%CI: 1.23-2.35), long-term use of an indwelling catheter (OR = 3.03; 95%CI: 1.59-6.59), a ureteral stent (OR = 1.54; 95%CI: 1.16-2.06), diabetes (OR = 1.17; 95%CI: 0.97-1.41), hypertension (OR = 1.6; 95%CI: 1.26-2.28), acute rejection process (OR = 2.22; 95%CI: 1.45-3.4), and abnormal urinary tract anatomy (OR = 2.87; 95%CI 1.44-5.74).

CONCLUSION

This meta-analysis revealed that UTIs are a significant problem in kidney recipients. Factors such as female sex, old age, history of UTIs, deceased donor, long-term use of an indwelling catheter, diabetes, acute rejection process, use of ureteral stent, abnormal urinary tract anatomy, and hypertension were related to an increased risk of UTIs in kidney recipients.

Recurrent Urinary Tract Infection in Living Donor Renal Transplant Recipients and the Role of Behavioral Education Program in Management: A Single-Center Experience

BACKGROUND

Urinary tract infections (UTIs) are the most prevalent type of kidney transplant (KT) recipients. We aimed to investigate the incidence, causes, and clinical impact of early recurrent UTI post-living donor KT and to examine the role of behavioral education program in management.

METHODS

This retrospective cohort chart-review study included all KT recipients with recurrent UTI necessitating hospital admission between September 2017 and August 2021. All patients with recurrent UTI were subjected to behavioral education for a month.

RESULTS

UTI was found in 14 of 145 patients (9.6%), with recurrent UTI in 11 (7.6%). A total of 93% of UTIs occurred during the first 6 months post-transplant and represented 52% of KT readmissions during the same period. A total of 64.3% of patients were older than 50 years. The mean (SD) length of hospital stay was 5 (2.5) days, with an equal incidence in both sexes. The most common bacterial isolates in early recurrent UTI were Escherichia coli in 80.9%. Both Extended-spectrum beta-lactamases and multidrug-resistant organisms (resistance in ≥3 drugs) were seen in 82.4% of isolates. Furthermore, the most effective antibiotic was meropenem, with 86.7% effectiveness. A total of 65% of UTIs were managed with a single antibacterial course. A total of 64.3% of patients were older than 50 years. In patients who developed UTI, the mean (SD) serum creatinine was 1.31 (0.52) mg/dL, with a mean increase in serum creatinine of 0.19 mg/dL on having the episodes; at 1 year post-transplant, serum creatinine declined to 1.23 (0.43) mg/dL. Four patients (36%) had no recurrence of UTI after behavioral education.

CONCLUSIONS

The multidrug-resistant bacterial isolates account for 82.4% of the UTIs. Therefore, antibiotic prescription should follow the antimicrobial stewardship guidelines. Behavioral education significantly reduced the incidence of recurrent UTI.

Influence of Graft Ureter Length, a Donor-Related Factor, on Urinary Tract Infections After Living-Donor Kidney Transplantation: A Single-Center Analysis of 211 Cases

Urinary tract infection (UTI) occurs in 25% of recipients of living-donor kidney transplantation (LDKT). Female sex, age, and anatomical abnormalities have been reported as recipient-related risk factors for UTI after LDKT; few studies have reported donor-related factors. We retrospectively examined UTI occurrence within 5 years of transplantation in recipients (n = 211) who underwent LDKT at our hospital between April 2011 and April 2021. All nephrectomies were performed using a retroperitoneal pure laparoscopic approach. The ureter was dissected at the lower level of the common iliac artery and trimmed to the shortest length, enough to reach the bladder using extra vesicular ureterocystoneostomy with a 3 cm submucosal tunnel. Twenty-nine recipients (13.7%) developed UTI within 5 years, and the median time to onset was 40.0 days. After adjusting for the well-known factors, including recipient sex, graft ureter length was an independent factor for UTI occurrence (HR 1.25, 95% CI 1.02∼1.53, p = 0.028) in the multivariate Cox regression analysis. The long ureter is usually trimmed, and the widest part is used for anastomosis, which may increase the possibility of reflux from the bladder to the ureter in the standard technique. The ureter length may be associated with the incidence of UTI after LDKT.

Analysis of Complications and Recipients' and Graft Survival in Patients 60 Years of Age and Older in the Long-Term Follow-up Period After Kidney Transplant: A Single-Center, Paired Kidney Analysis

BACKGROUND

Long-term results of kidney transplant (KTx) in older patients may differ from younger recipients owing to increased cardiovascular comorbidities. The study aimed to analyze surgical and nonsurgical complications that develop in the long-term follow-up period after KTx, and factors that influence results of KTx in recipients aged 60 years and older (≥60) compared with younger recipients (<60).

METHODS

One hundred seventy-five patients aged ≥60 years and 175 patients aged <60 years who received a kidney graft from the same deceased donor were enrolled in the study. In the long-term follow-up period (3 months to 5 years after KTx) the incidence of surgical and nonsurgical complications, as well as patient and kidney graft survival, were compared. Additionally, the influence of early complications on patients and kidney graft survival was assessed.

RESULTS

There were no differences between recipients aged ≥60 years compared with recipients aged <60 years in occurrence of surgical complications (graft artery stenosis: 0.6% vs 2.3%; ureter stenosis: 3.4% vs 1.1%; lymphocele: 6.9% vs 3.4%) and nonsurgical complications (urinary tract infection: 19.4% vs 23.4%; pneumonia: 8.6% vs 8.6%; cytomegalovirus infection: 6.3% vs 8%; new-onset diabetes after transplant: 16.6% vs 17.1%; cancer incidence: 5.7% vs 4.6%; acute rejection episode: 13.1% vs 17.1%). Five-year recipient survival was lower in a group of patients aged ≥60 years (death, 15.4% vs 8%; death with functioning graft, 12% vs 5.1%).

CONCLUSIONS

The incidence of surgical and nonsurgical complications, as well as kidney-graft survival, in recipients aged ≥60 years in a 5-year follow-up period is comparable to younger recipients aged <60 years.

Risk Factors and Outcomes of Acute Graft Pyelonephritis with Bacteremia Due to Multidrug-Resistant Gram-Negative Bacilli among Kidney Transplant Recipients

Acute graft pyelonephritis (AGP) is the leading cause of bloodstream infection in kidney transplant (KT) recipients. The prevalence of urinary tract infections caused by multidrug-resistant (MDR) Gram-negative bacilli is increasing. This 14-year prospective observational study sought to determine the clinical characteristics, risk factors, and outcomes of AGP with bacteremia due to MDR Gram-negative bacilli. Overall, 278 episodes of AGP with bacteremia due to MDR Gram-negative and non-MDR Gram-negative bacilli were identified and compared in 214 KT recipients; MDR Gram-negative bacilli were the cause in 28.4%. Overall 30-day mortality was low (1.1%). Risk factors independently associated with AGP due to MDR Gram-negative bacilli were male sex (OR 3.08; 95%CI 1.60–5.93), previous episode of bacteremic AGP (OR 2.11, 95%CI 1.09–4.09), prior antibiotic therapy in the preceding month (OR 2.47, 95%CI 1.33–4.57), and nosocomial acquisition (OR 2.03, 95%CI 1.14–3.62). Forty-three percent of MDR Gram-negative episodes received inappropriate empirical antibiotic therapy. The risk factors identified in this study may help physicians when selecting empirical antibiotic treatment for AGP. Previous antibiotic use was the main modifiable factor. Its presence highlights the importance of avoiding unnecessary antibiotics in order to bring down the high rates of MDR Gram-negative bacilli infections in this population.

Distribution and Antibiotic Susceptibility Pattern of Multidrug-Resistant Bacteria and Risk Factors Among Kidney Transplantation Recipients with Infections Over 13 Years: A Retrospective Study

Background

Infection ranks as the most common complication after kidney transplantation (KT) and threatens outcomes of kidney transplantation recipients (KTR). This study aimed to investigate the microbiological profile of infection, assess bacterial resistance and identify risk factors for multidrug-resistant (MDR) bacterial infection among KTR.

Methods

During the study period, 866 recipients underwent kidney transplant surgery. We studied the distribution of pathogens, resistance rate of MDR bacteria and the risk factors of MDR bacterial infection.

Results

Totally, 214 species of pathogens (110 species were MDR bacteria) were isolated in 119 KTR. Escherichia coli (E. coli) was the most common bacteria of the infection. MDR extended spectrum β-lactamase (ESBL)-producing Enterobacteriaceae (ESBL-E) were most resistant to ampicillin, cefazolin, ciprofloxacin and complex sulfamethoxazole, while quite sensitive to imipenem, amikacin and piperacillin/tazobactam (PIT). All MDR gram-positive bacteria were quite sensitive to linezolid and vancomycin, except that MDR Staphylococcus was also susceptible to rifampicin. Female gender (OR = 3.497, 95% CI = 1.445–8.467, P = 0.006), pathogen types > 1 (OR = 3.832, 95% CI = 1.429–10.273, P = 0.008) and postoperative time < 3 months (OR = 0.331, 95% CI = 0.137–0.799, P = 0.014) were independent risk factors for MDR bacterial infection.

Conclusion

PIT and amikacin may be an alternative choice of ESBL-E infection. Rifampicin can also be prescribed for MDR Staphylococcus infection. MDR bacterial infection was associated with female gender, pathogen types more than 1 and 3 months postoperative period.

Urinary Tract Infections in Kidney Transplant Recipients-Is There a Need for Antibiotic Stewardship?

(1) Background: Urinary tract infections (UTI) are the most common infections after kidney transplantation. Given the risk of urosepsis and the potential threat to the graft, the threshold for treating UTI and asymptomatic bacteriuria with broad spectrum antibiotics is low. Historically fluoroquinolones were prescription favorites for patients that underwent kidney transplantation (KT). After the recent recommendation to avoid them in these patients, however, alternative treatment strategies need to be investigated (2) Methods: We retrospectively analyzed the charts of 207 consecutive adult kidney transplantations that were performed at the department of General, Visceral and Transplantation Surgery of the University Hospital of Tuebingen between January 2015 and August 2020. All charts were screened for the diagnosis and treatment of asymptomatic bacteriuria (ASB) and urinary tract infections (UTI) and the patients' clinical characteristics and outcomes were evaluated. (3) Results: Of the 207 patients, 68 patients suffered from urinary tract infections. Patients who developed UTI had worse graft function at discharge (p = 0.024) and at the 12 months follow-up (p < 0.001). The most commonly prescribed antibiotics were Ciprofloxacin and Piperacillin/Tazobactam. To both, bacterial resistance was more common in the study cohort than in the control group. (4) Conclusions: Urinary tract infections appear to be linked to worse graft functions. Thus, prevention and treatment should be accompanied by antibiotic stewardship teams.

Short versus prolonged antibiotic treatment for complicated urinary tract infection after kidney transplantation

There is no consensus regarding the optimal duration of antibiotic therapy for urinary tract infection (UTI) following kidney transplantation (KT). We performed a retrospective study comparing short (6-10 days) versus prolonged (11-21 days) antibiotic therapy for complicated UTI among KT recipients. Univariate and inverse probability treatment weighted (IPTW) adjusted multivariate analysis for composite primary outcome of all-cause mortality or readmissions within 30 days and relapsed UTI 180 days were performed. Overall, 214 KT recipients with complicated UTI were included; 115 short-course treatment (median 8, interquartile range [IQR] 6-9 days), 99 prolonged course (median 14, IQR 12-21 days). The composite outcome occurred in 33 (28.6%) in the short-course group and 30 (30%) in the prolonged-course group; relapsed UTI occurred in 19 (16.5%) vs. 21 (21%), respectively. Duration of antibiotic treatment was not associated with any of these outcomes. The only risk factor for mortality/readmissions in multivariate analysis was deceased donor. No differences between groups were demonstrated for length of hospital stay, rates of bacteraemia, resistance development, and serum creatinine at 30 and 90 days. In conclusion, we found no difference in clinical outcomes between KT recipients treated for complicated UTI with short-course antibiotic (6-10 days) versus longer course (11-21 days).

A Current Review of the Etiology, Clinical Features, and Diagnosis of Urinary Tract Infection in Renal Transplant Patients

Urinary tract infection (UTI) represents the most common infection after kidney transplantation and remains a major cause of morbidity and mortality in kidney transplant (KT) recipients, with a potential impact on graft survival. UTIs after KT are usually caused by Gram-negative microorganisms. Other pathogens which are uncommon in the general population should be considered in KT patients, especially BK virus since an early diagnosis is necessary to improve the prognosis. UTIs following kidney transplantation are classified into acute simple cystitis, acute pyelonephritis/complicated UTI, and recurrent UTI, due to their different clinical presentation, prognosis, and management. Asymptomatic bacteriuria (ASB) represents a frequent finding after kidney transplantation, but ASB is considered to be a separate entity apart from UTI since it is not necessarily a disease state. In fact, current guidelines do not recommend routine screening and treatment of ASB in KT patients, since a beneficial effect has not been shown. Harmful effects such as the development of multidrug-resistant (MDR) bacteria and a higher incidence of Clostridium difficile diarrhea have been associated with the antibiotic treatment of ASB.

The Impact of Timing of Stent Removal on the Incidence of UTI, Recurrence, Symptomatology, Resistance, and Hospitalization in Renal Transplant Recipients

Purpose

To evaluate the impact of early (<3 weeks) versus late (>3 weeks) urinary stent removal on urinary tract infections (UTIs) post renal transplantation.

Methods

A retrospective study was performed including all adult renal transplants who were transplanted between January 2017 and May 2020 with a minimum of 6-month follow-up at King Abdulaziz Medical City, Riyadh, Saudi Arabia.

Results

A total of 279 kidney recipients included in the study were stratified into 114 in the early stent removal group (ESR) and 165 in the late stent removal group (LSR). Mean age was 43.4 ± 15.8; women: n: 114, 40.90%; and deceased donor transplant: n: 55, 19.70%. Mean stent removal time was 35.3 ± 28.0 days posttransplant (14.1 ± 4.6 days in the ESR versus 49.9 ± 28.1 days in LSR, p < 0.001). Seventy-four UTIs were diagnosed while the stents were in vivo or up to two weeks after the stent removal “UTIs related to the stent” (n = 20, 17.5% in ESR versus n = 54, 32.7% in LSR; p=0.006). By six months after transplantation, there were 97 UTIs (n = 36, 31.6% UTIs in ESR versus n = 61, 37% in LSR; p=0.373). Compared with UTIs diagnosed after stent removal, UTIs diagnosed while the stent was still in vivo tended to be complicated (17.9% versus 4.9%, p: 0.019), recurrent (66.1% versus 46.3%; p: 0.063), associated with bacteremia (10.7% versus 0%; p: 0.019), and requiring hospitalization (61% versus 24%, p: 0.024). Early stent removal decreased the need for expedited stent removal due to UTI reasons (rate of UTIs before stent removal) (n = 11, 9% in the early group versus n = 45, 27% in the late group; p=0.001). The effect on the rate of multidrug-resistant organisms (MDRO) was less clear (33% versus 47%, p: 0.205). Early stent removal was associated with a statistically significant reduction in the incidence of UTIs related to the stent (HR = 0.505, 95% CI: 0.302-0.844, p=0.009) without increasing the incidence of urological complications. Removing the stent before 21 days posttransplantation decreased UTIs related to stent (aOR: 0.403, CI: 0.218-0.744). Removing the stent before 14 days may even further decrease the risk of UTIs (aOR: 0.311, CI: 0.035- 2.726).

Conclusion

Early ureteric stent removal defined as less than 21 days post renal transplantation reduced the incidence of UTIs related to stent without increasing the incidence of urological complications. UTIs occurring while the ureteric stent still in vivo were notably associated with bacteremia and hospitalization. A randomized trial will be required to further determine the best timing for stent removal.

Overview on urinary tract infection, bacterial agents, and antibiotic resistance pattern in renal transplant recipients

Background:

Urinary tract infection (UTI) is a mainly common infection in kidney transplant recipients. This study decided to investigate UTI, bacterial agents, and antibiotic resistance pattern in kidney transplant recipients from Iran.

Materials and Methods:

Search process was conducted for UTI, bacterial agents, and antibiotic resistance pattern in kidney transplant recipients from Iran via electronic databases (Scopus, PubMed, Web of Science, etc.,) with Mesh terms in either Persian and English languages without limited time to May 31, 2020. Data were analyzed by comprehensive meta-analysis software.

Results:

The combined prevalence of UTI in renal transplant recipients was reported by 31.1%. The combined prevalence of Gram-negative bacteria was 69%. The most common pathogens among Gram negatives were E. coli followed by Klebsiella pneumoniae with frequency 43.4% and 13%, respectively. Subgroup analysis for Gram-positive bacteria showed the combined prevalence of 31%. The most common microorganism among Gram positives belonged to coagulase-negative Staphylococci and Enterococci with a prevalence of 10.2% and 9%, respectively. Subgroup meta-analysis of antibiotic resistance for Gram-negative showed the most resistance to cephalexin followed by carbenicillin with a prevalence of 89.1% and 87.3%, respectively.

Conclusion:

Our review showed a noticeable rate of UTI (31.1%) among renal transplant recipients in Iran and a high prevalence of Gram-negative (69%) and Gram-positive (13%) microorganisms. A high resistance rate was seen against almost all antibiotics used for the treatment of UTI. Therefore, empirical prescription of antibiotics should be avoided, and it should be based on data obtained from antibiogram tests.

Carbapenem-resistant Enterobacteriaceae among kidney transplant recipients - insights on the risk of acquisition and CRE infection

BACKGROUND

Kidney transplant recipients are a risk group for carbapenem-resistant Enterobacteriaceae infection.

OBJECTIVES

This study aimed to identify risk factors for CRE acquisition and infection among kidney transplant recipients.

METHODS

We conducted a case-control study; we defined the case as kidney transplant recipient with positive culture for carbapenem-resistant Enterobacteriaceae identified between January 2010 and February 2019. Controls were chosen among kidney transplant recipients hospitalized in the same period of cases (1:2). Surveillance culture for carbapenem-resistant Enterobacteriaceae was performed at admission and weekly during hospital stay. The risk factors analysis for carbapenem-resistant Enterobacteriaceae infection was performed among patients colonized by these bacteria.

RESULTS

We identified 331 patients colonized with carbapenem-resistant Enterobacteriaceae; The median time from transplantation to first carbapenem-resistant Enterobacteriaceae positive culture was 42 days (range from 3 to 7399 days); 125(37.8%) patients developed infection; the most common site was urinary tract. Risk factors for carbapenem-resistant Enterobacteriaceae acquisition were recipient age >45-year, diabetes nephropathy, donor age >55-year, ureteral stent at kidney transplantation, delay of graft function, median lymphocytes count <800cells/mm³, and acute cellular rejection. Risk factors for carbapenem-resistant Enterobacteriaceae infection were recipient age at CRE acquisition >50-year; median lymphocytes count ≤700 cells/mm³, carbapenem use, and colonization by polymyxin-resistant strain. Patients colonized by polymyxin and carbapenem resistant Enterobacteriaceae strain who used carbapenem had a 93.8% probability of developing infection by this agent.

CONCLUSION

Carbapenem-resistant Enterobacteriaceae acquisition after kidney transplant is related to graft conditions, immunosuppression degree. Among carbapenem-resistant Enterobacteriaceae colonized patients, special attention is needed for those harbouring polymyxin-resistant strains.

Efficacy and Safety of SGLT-2 Inhibitors for Treatment of Diabetes Mellitus among Kidney Transplant Patients: A Systematic Review and Meta-Analysis

BACKGROUND

The objective of this systematic review was to evaluate the efficacy and safety profiles of sodium-glucose co-transporter 2 (SGLT-2) inhibitors for treatment of diabetes mellitus (DM) among kidney transplant patients.

METHODS

We conducted electronic searches in Medline, Embase, Scopus, and Cochrane databases from inception through April 2020 to identify studies that investigated the efficacy and safety of SGLT-2 inhibitors in kidney transplant patients with DM. Study results were pooled and analyzed utilizing random-effects model.

RESULTS

Eight studies with 132 patients (baseline estimated glomerular filtration rate (eGFR) of 64.5 ± 19.9 mL/min/1.73m2) treated with SGLT-2 inhibitors were included in our meta-analysis. SGLT-2 inhibitors demonstrated significantly lower hemoglobin A1c (HbA1c) (WMD = -0.56% [95%CI: -0.97, -0.16]; p = 0.007) and body weight (WMD = -2.16 kg [95%CI: -3.08, -1.24]; p < 0.001) at end of study compared to baseline level. There were no significant changes in eGFR, serum creatinine, urine protein creatinine ratio, and blood pressure. By subgroup analysis, empagliflozin demonstrated a significant reduction in body mass index (BMI) and body weight. Canagliflozin revealed a significant decrease in HbA1C and systolic blood pressure. In terms of safety profiles, fourteen patients had urinary tract infection. Only one had genital mycosis, one had acute kidney injury, and one had cellulitis. There were no reported cases of euglycemic ketoacidosis or acute rejection during the treatment.

CONCLUSION

Among kidney transplant patients with excellent kidney function, SGLT-2 inhibitors for treatment of DM are effective in lowering HbA1C, reducing body weight, and preserving kidney function without reporting of serious adverse events, including euglycemic ketoacidosis and acute rejection.

Institutional protocol adherence in the incidence of recurrent urinary tract infection after kidney transplantation

OBJECTIVES

Recurrent urinary tract infections (rUTIs) occur frequently after kidney transplantation (KT), however their optimal management remains undefined. This study aimed to identify risk factors for rUTI and to validate a protocol for UTI and rUTI treatment after KT.

METHODS

This retrospective cohort study involved patients undergoing KT between January 2013 and July 2016. Patients were followed-up from day of KT until graft loss, death or end of follow-up (31 December 2018). We analysed all episodes of symptomatic UTI. The main outcome measure was rUTI after KT. Analysis was done per episode in a multilevel approach; patient features were considered in the distal level and UTI features in the proximal level. Univariate and multivariate analyses were performed by Cox regression. A propensity score was used to adjust the risk of patients with carbapenem-resistant Enterobacteriaceae.

RESULTS

During the study period, 787 patients underwent KT, of whom 152 (19.3%) developed 356 UTI episodes. The most common micro-organisms wereEscherichia coli (165/356; 46.3%) and Klebsiella pneumoniae (101/356; 28.4%). Multidrug-resistant micro-organisms were isolated in 161 UTIs (45.2%). Risk factors for rUTI were diabetic nephropathy as the cause of end-stage renal disease (P = 0.02), UTI in first 180 days after KT (P = 0.04), anatomic alteration of the urinary tract at UTI diagnosis (P = 0.004) and length of time to effective therapy (P = 0.002); UTI treatment duration according to institutional protocol (P = 0.04) was the only protective factor identified.

CONCLUSION

Appropriate therapy duration has an impact on rUTI prevention after KT.

Predictive factors and management of urinary tract infections after kidney transplantation: a retrospective cohort study

BACKGROUND

Urinary tract infection (UTI) is one of the most common infectious complications in kidney transplant recipients. The aims of our study were to identify possible predictive factors for UTI and advocate for the management of UTI after kidney transplantation (KT).

METHODS

Between January 2013 and December 2018, 182 adult patients with end-stage kidney disease who underwent KT were retrospectively analyzed. Patients who had urinary symptoms and positive urine culture were diagnosed with UTI. The types of urinary bacteria causing UTIs were also examined.

RESULTS

UTIs occurred in forty-one patients (25.1%), and the median time to UTI onset (UTI-free survival) after KT was 189 days. The Cox hazard regression analysis showed that the predictive factors for UTI onset were as follows: posttransplant urinary catheterization, including indwelling urinary catheterization and clean intermittent catheterization; a maximum bladder capacity before KT of less than 150 ml; and a low serum albumin level at 1 month after KT. The most common causative agent was Escherichia coli (56.6%), followed by Enterococcus spp. (15.6%) and Klebsiella spp.

CONCLUSIONS

Kidney transplant recipients with prolonged postoperative malnutrition, posttransplant voiding dysfunction and/or urinary storage disorder had an increased risk of UTI. Bladder function tests, such as uroflowmetry, postvoid residual urine tests, and urodynamic tests, were needed to predict UTI. For patients with malnutrition, care should be taken to ensure sufficient calorie intake. Kidney transplant recipients who develop UTI should be treated as complicated UTI patients.

Fosfomycin-trometamol for Urinary Tract Infections in Kidney Transplant Recipients

BACKGROUND

The treatment of urinary tract infections (UTIs) in kidney transplant recipients (KTRs) with oral antibiotics is complicated by increasing resistance to trimethoprim-sulfamethoxazole, amoxicillin/clavulanic acid, and ciprofloxacin. Fosfomycin-trometamol (FT) could be an alternative, but evidence on clinical effectiveness is scarce. We evaluated the use, effectiveness and safety of FT for UTI in KTRs.

METHODS

Data were retrospectively collected in 2 Dutch transplant hospitals from adult KTRs that were treated with FT as initial treatment for lower UTI or asymptomatic bacteriuria (ASB) or as stepdown treatment for upper UTI after initial intravenous antibiotics. Exclusion criteria were in vitro resistance to FT or concomitant antibiotic treatment. Endpoints were clinical cure within 14 days and severe clinical failure, microbiological cure, relapse, recurrence, and acquired resistance within 90 days postend of treatment.

RESULTS

Fifty-three episodes in 40 KTRs were included (ASB, n = 15; lower UTI, n = 33; upper UTI, n = 5). Fosfomycin-trometamol was used for a median short duration in a heterogeneous gift interval. Fosfomycin-trometamol resulted in microbiological cure in 25%, 28%, and 100% of ASB, lower UTI and upper UTI with initial positive culture and follow-up culture performed, respectively. Clinical cure rates were 67% for lower UTI and 80% for upper UTI. Relapses or recurrences occurred in 31% and 24% of symptomatic UTI episodes, without severe clinical failure. Acquired resistance to fosfomycin was observed in 6 episodes.

CONCLUSIONS

Fosfomycin-trometamol has a reasonable effectiveness as last-resort oral treatment for lower UTI and stepdown treatment for upper UTI in KTRs. Randomized controlled trials with optimal dosage regimens are warranted. Use of FT is not recommended for ASB.

Early Complications After Kidney Transplantation in Patients Aged 60 Years and Older: A Single-Center, Paired-Kidney Analysis

OBJECTIVES

As the population ages, the number of people suffering from cardiovascular diseases (CVD) and diabetes mellitus (DM) increases. The coexistence of these diseases can affect the results of kidney transplantation (KT) in the elderly. The aim of this study was to analyze surgical and nonsurgical complications in the early period after KT and to identify the factors that influence their development in recipients aged ≥ 60 years compared to younger recipients < 60 years.

METHODS

One hundred seventy-five recipients of KT ≥ 60 years and 175 recipients of KT < 60 years who received kidneys from the same deceased donor were enrolled into the study. The incidence of surgical and nonsurgical complications, factors that may influence their development, early graft function, and patient and kidney-graft survival were analyzed during a 3-month follow-up period. Donor sources complied with the Helsinki Congress and Istanbul Declaration and organs were not procured from prisoners and individuals who were coerced or paid.

RESULTS

Older recipients were characterized by higher body mass index ± SD (26.1 ± 3.5 vs 24.7 ± 3.4 kg/m²) and suffered more often from pretransplant DM (20.6% vs 11.4%) and CVD (34.3% vs 10.3%) and less frequently underwent previous KT (6.3% vs 20.0%). There were no differences between the ≥ 60 year old and < 60 year old groups in reference to surgical (20.6% vs 24%) and nonsurgical complications (28.6% vs 27.4%), early graft function, serum creatinine, and proteinuria. Recipients (95.4% vs 97.1%) and kidney-graft survival (93.1% vs 95.4%) were similar in both groups. The recipient factors that influenced the development of infectious complications were age, dialysis duration, pretransplant DM, and CVD.

CONCLUSIONS

Despite higher co-incidence of CVD and DM, the risk of surgical and nonsurgical complications in elderly recipients is comparable to younger recipients in the early period after KT.

Five compelling UTI questions after kidney transplant

PURPOSE

Urinary tract infection (UTI) is the most common bacterial infection among infectious complications in kidney transplant recipients (KTR). After transplantation, infections can result from surgical complications, donor-derived infections, pre-existing recipient infections, and nosocomial infections. Post-transplant infection is still a major cause of morbidity, mortality, graft dysfunction and rejection. In this paper, we aimed to review a few compelling questions in kidney transplantation (KTX).

METHODS

To identify relevant clinical questions regarding KTX and UTI a meeting was conducted among physicians involved in the KT program in our hospital. After discussion, several clinically relevant questions related to UTI after KTX. The 5 first rated in importance were judged generalizable to other clinical settings and selected for the purposes of this review.

RESULTS

Nearly half of the patients present in the first three months of transplant with UTI. The most common uropathogens in post-transplant UTIs are Escherichia coli, Klebsiella pneumoniae, and Enterococcus faecalis. Risk factors for UTI include female sex, advanced age, recurrent UTI before transplant, prolonged urethral catheterization, delayed graft function, and cadaveric kidney transplant.

CONCLUSION

The incidence of post-transplant UTI is similar in both developed and developing countries. E.coli is the most common pathogen in most of studies. Cadaveric donor and post-dialysis transplantation are defined as independent risk factors for post-transplant UTI. Further studies are still required to identify risk factors after kidney transplantation and UTI's importance for graft function and patient outcome.

Urinary tract infections in renal transplant recipients at a quaternary care centre in Australia

Background

Urinary tract infections (UTI) are the most common of infections after renal transplantation. The consequences of UTIs in this population are serious, with increased morbidity and hospitalisation rates as well as acute allograft dysfunction. UTIs may impair overall graft and patient survival. We aimed to identify the prevalence and risk factors for post-transplant UTIs and assess UTIs’ effect on renal function during a UTI episode and if they result in declining allograft function at 2 years post-transplant. Additionally, the causative organism, the class of antibacterial drug employed for each UTI episode and utilisation rates of trimethoprim/sulfamethoxazole (TMP/SMX) prophylaxis were also quantified.

Methods

This was a retrospective study of 72 renal transplant patients over a 5-year period who were managed at the Royal Brisbane and Women’s Hospital. Patient charts, pathology records and dispensing histories were reviewed as part of this study and all UTIs from 2 years post transplantation were captured.

Results

Of these patients, 20 (27.8%) had at least one UTI. Older age (p = 0.015), female gender (p < 0.001), hyperglycaemia (p = 0.037) and acute rejection episodes (p = 0.046) were risk factors for developing a UTI on unadjusted analysis. Female gender (OR 4.93) and age (OR 1.03) were statistically significant risk factors for a UTI on adjusted analysis. On average, there was a 14.4% (SEM 5.20) increase in serum creatinine during a UTI episode, which was statistically significant (p = 0.027), and a 9.1% (SEM 6.23) reduction in serum creatinine after the UTI episode trending toward statistical significance.

(p = 0.076). Common organisms (Escherichia coli and Klebsiella pneumoniae) accounted for 82% of UTI episodes with 70% of UTI cases requiring only a single course of antibiotic treatment. Furthermore, the antibiotic class used was either a penicillin (49%) or cephalosporin (36%) in the majority of UTIs. The use of TMP/SMX prophylaxis for Pneumocystis carinii pneumonia prophylaxis did not influence the rate of UTI, with > 90% of the cohort using this treatment.

Conclusions

There was no significant change in serum creatinine and estimated glomerular filtrate rate from baseline to 2 years post-transplant between those with and without a UTI.

Urinary tract infection in children with nephrotic syndrome: A systematic review and meta-analysis

OBJECTIVE

Urinary tract infection (UTI) is among the most common infection diseases in children with nephrotic syndrome (NS), resulting in treatment failure and relapse. No systematic reviews have estimated the prevalence of UTI in children with NS on a global scale, therefore, did the first systematic review and meta-analysis study to estimate the prevalence of UTI in children with NS in different geographical regions and different countries.

METHODS

PubMed, EMBASE, Scopus, Web of Science and Google Scholar databases were systematically searched up to 20 February 2019, for studies assessing the prevalence of UTI in children with NS. Pooled prevalence of UTI was calculated using the random effects model. Data were stratified based on WHO geographical regions and individual countries. Subgroup analysis regarding the gender and socio-demographic variables were also performed.

RESULTS

Thirty studies involving 6314 children with NS were included. The pooled prevalence of UTI was 21.6% (95%CI, 17.1-26.5%), with the highest prevalence in the African region (34.8%, 95%CI: 4.7-73.9%), and lowest prevalence in the region of the Americas (7.4%, 95% CI: 1.7-16.2%). With respect to countries, the lowest and highest prevalence rates were reported from USA (3.3%) and Indonesia (45.9%). In subgroup analyses, a higher prevalence was observed in females, and in countries with lower levels of income and human development index. The most common isolated bacteria were Escherichia coli (28%), and Klebsiella spp. (22.4%).

CONCLUSIONS

The high prevalence of UTI in children with NS reported in this study is a significant health threat for these patients. These results call for intervention strategies and preventive measures for children with NS to reduce the burden of UTI.

Risk Factors for Urinary Tract Infection After Kidney Transplant: A Retrospective Analysis

OBJECTIVES

Urinary tract infections are the most common type of infections in kidney transplant recipients. They are also important factors for increased morbidity and mortality. The aims of this study were to evaluate the number of urinary tract infections, to identify possible donor/receiver-based risk factors, and to evaluate the impact of these infections on graft function.

MATERIALS AND METHODS

Medical records of patients who had undergone kidney transplant between 2010 and 2017 were retrospectively analyzed.

RESULTS

Our study included 145 patients (49 women [33.8%] and 96 men [66.2%]), with mean age of 35.2 ± 12.4 years. There were 105 episodes of urinary tract infections in 55 of 145 patients (37.9%) during the first year after transplant. Female sex (P = .001), glomerulonephritis as primary kidney disease (P = .04), pretransplant diabetes (P = .05), and presence of ureteral stent (P = .03) were significant risk factors for the development of urinary tract infections. The most frequent pathogens identified were Escherichiacoli and Klebsiella pneumoniae. Mean glomerular filtration rate t 12 months was significantly lower in patients with urinary tract infection than in patients without infection (80 ± 25 vs 68 ± 28 mL/min; P = .006).

CONCLUSIONS

In kidney transplant recipients, urinary tract infections are common complications and have negative outcomes on graft function. These infections remain an important disease that requires frequent investigations and new ways of approach for prevention.

Phenotypic and Genotypic Characterization of Escherichia coli Causing Urinary Tract Infections in Kidney-Transplanted Patients

Urinary tract infection (UTI), frequently caused by uropathogenic Escherichia coli (UPEC), is the most common infection after kidney transplantation (KTx). Untreated, it can lead to urosepsis and impairment of the graft function. We questioned whether the UPEC isolated from KTx patients differed from the UPEC of non-KTx patients. Therefore, we determined the genome sequences of 182 UPEC isolates from KTx and control patients in a large German university clinic and pheno- and genotypically compared these two isolated groups. Resistance to the β-lactams, trimethoprim or trimethoprim/sulfamethoxazole was significantly higher among UPEC from KTx than from control patients, whereas both the isolated groups were highly susceptible to fosfomycin. Accordingly, the gene content conferring resistance to β-lactams or trimethoprim, but also to aminoglycosides, was significantly higher in KTx than in control UPEC isolates. E. coli isolates from KTx patients more frequently presented with uncommon UPEC phylogroups expressing higher numbers of plasmid replicons, but interestingly, less UPEC virulence-associated genes than the control group. We conclude that there is no defining subset of virulence traits for UPEC from KTx patients. The clinical history and immunocompromised status of KTx patients enables E. coli strains with low uropathogenic potential, but with increased antibiotic resistance to cause UTIs.

Urinary tract infections in solid organ transplant recipients: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of urinary tract infections (UTI) in solid organ transplantation, focusing on kidney transplant (KT) recipients. KT recipients have unique risk factors for UTI, including indwelling stents and surgical manipulation of the genitourinary tract. KT recipients experience multi-drug antibiotic-resistant infections-UTI prevention and management strategies must consider risks of antimicrobial resistance. Non-antimicrobial prevention strategies for UTI in KT recipients are reviewed. It is important to recognize that some renal transplant recipients with UTI may primarily present with fever, malaise, leukocytosis, or a non-specific sepsis syndrome without symptoms localized to the urinary tract. However, asymptomatic bacteriuria (AB) must be distinguished from UTI because AB is not necessarily a disease state. Accumulating data indicate that there are no benefits of antibiotics for treatment of AB in KT recipients more than 2 months after post-transplant. Further research is needed on management of AB in the early (<2 months) post-transplant period, prophylaxis for UTI in this era of antibiotic resistance, recurrent UTI, non-antimicrobial prevention of UTI, and uropathogens identified in donor urine and/or preservative fluid cultures.

Updates on urinary tract infections in kidney transplantation

Urinary tract infection (UTI) represents the most common infection after kidney transplantation; it is associated with an increased risk for acute kidney rejection and impaired graft function in the early post-transplant period. Kidney transplant recipients with UTIs are often clinically asymptomatic due to the immunosuppressive therapy; however, asymptomatic bacteriuria may progress to acute pyelonephritis, bacteremia and urosepsis, particularly in the early post-transplant period, that are independent risk factors for short and long-term graft and patient survival. This article reviews the definitions, incidence, risk factors and the management of UTI in kidney transplant recipients; furthermore, the main controversial and still unanswered questions, regarding the causes of recurrent UTIs, adequate use of antibiotics to avoid antibiotic resistance, dosing and timing for prophylaxis and treatment of symptomatic infections, are also discussed. The emerging definition of urinary microbiota introduces new concepts in understanding the complexity of the disease and might represent the future target for therapeutic interventions.

Incidence Rate of Post-Kidney Transplant Infection: A Retrospective Cohort Study Examining Infection Rates at a Large Canadian Multicenter Tertiary-Care Facility

Background

Reducing post-operative infections among kidney transplant patients is critical to improve long-term outcomes. With shifting disease demographics and implementation of new transplantation protocols, frequent evaluation of infection rate and type is necessary.

Objective

Our objectives were to assess the incidence and types of post-operative infections in kidney transplant recipients at a large tertiary-care facility and determine sample sizes needed for future intervention trials.

Design

Retrospective cohort study.

Setting

The Ottawa Hospital, Ottawa, Ontario.

Patients

Adult kidney transplant patients, N = 142.

Measurements

Demographic data, transplant protocol, infections up to 2 years following transplantation.

Methods

Infections within 2 years following transplantation in all kidney transplant recipients between January 2011 and December 2012 were reviewed. Sample sizes were determined using all-cause infection rates and infection-free survival data.

Results

Of 142 patients, 44 (31.0%) had at least one infection. The incidence of infection was 36.2 per 100 patient-years by 2 years post-transplant. A total of 32 (22.5%) patients had 56 infection-related hospitalizations with 73.2% occurring in the first year. In the first 2 years, urinary tract infections had the highest incidence (18.1 per 100 patient-years) followed by skin (3.9 per 100 patient-years), cytomegalovirus (3.9 per 100 patient-years), and bacteremia (3.9 per 100 patient-years). Results indicate that 206 patients per study arm would be needed to show a 30% reduction in the 2-year incidence of infection post-transplantation.

Limitations

Infection rates may be slightly underestimated due to the relatively short 2-year follow-up; however, the highest infection-risk period was captured within this time frame.

Conclusions

Infections post-kidney transplant are still common, particularly urinary tract infections. They are associated with significant morbidity and hospitalization. Given the feasible sample sizes calculated in this study, intervention trials are indicated to further reduce infection rates within the first 2 years post-kidney transplantation.

Does the urinary tract infection caused by carbapenem-resistant Gram-negative bacilli impact the outcome of kidney transplant recipients?

The incidence of urinary tract infection (UTI) after kidney transplantation (KT) caused by multidrug-resistant (MDR) bacteria is growing. The aim of this study was to analyze the impact of UTI caused by carbapenem-resistant Gram-negative bacteria (CR-GNB) in the survival of graft and recipients following KT. This was a retrospective cohort study involving patients who underwent KT between 2013 and 2016. Patients were followed since the day of the KT until loss of graft, death or end of the follow-up period (31th December 2016). The outcomes measured were UTI by MDR following KT and graft and patient survival. Analyses were performed using Cox regression; for the graft and patient survival analysis, we used a propensity score for UTI by CR-GNB to matching a control group. UTI was diagnosed in 178 (23.9%) of 781 patients, who developed 352 UTI episodes. 44.6% of the UTI cases were caused by MDR bacteria. Identified risk factors for UTI by MDR bacteria were DM, urologic disease as the cause of end-stage renal failure, insertion of ureteral stent, carbapenem use, and delayed graft function (DGF). Risk factors for death during the follow-up period were female gender, patients over 60 years old at the time of KT, DM, body mass index over 31.8, UTI caused by CR-GNB. In conclusion, UTIs caused by CR-GNB have great impact on patients' survival after KT.

European experience of robot-assisted kidney transplantation: minimum of 1-year follow-up

OBJECTIVES

To evaluate functional results, graft survival and late complications in patients who underwent robot-assisted kidney transplantation (RAKT) and who had a minimum of 1 year of follow-up data, and to analyse the correlations between surgical data and functional results at a minimum of 1-year postoperatively and between renal function in the immediate postoperative period and after 1 year.

MATERIALS AND METHODS

A common prospectively collected RAKT database was created by the European Robotic Urological Section (ERUS) RAKT working group, which included eight different European centres. In each centre RAKTs were performed with kidneys from living donors. Data on demographic variables, surgical results, graft survival, functional outcomes (creatinine and estimated glomerular filtration rate [eGFR]) on postoperative days 7 and 30 and at 1 year, and late complications were extracted from the common database.

RESULTS

A total of 147 RAKTs were performed by the ERUS RAKT working group. Of the 147 patients, 83 had at least 1-year follow-up (mean [range] 21 [13-27] months). Of these 83 patients, 30 were women. The patients' median (range) age was 43 (30-75) years, body mass index was 25.3 (20-40) kg/m² , pre-transplantation serum creatinine was 517 (198-1 414) μmol/L and estimated GFR (eGFR) was 10 (3-29) mL/min per 1.73 m² . Of the 83 cases, 46 were pre-emptive. The median (range) overall ischaemia time was 116 (53-377) min. The median (range) rewarming time was 60 (35-110) min. At 1-year follow-up, the median (range) serum creatinine was 131 (66-244) μmol/L, with a median (range) eGFR of 57.4 (28-97) mL/min per 1.73 m² . There was no statistically significant difference between functional data at postoperative day 30 and those at 1 year for creatinine (P = 0.78) or eGFR (P = 0.91). Regarding the correlation between the surgical data and the functional outcomes, the data showed that overall operating time and rewarming time did not affect the graft function at 1 year. Three cases of graft loss occurred as a result of massive arterial thrombosis within the first postoperative week. Late complications comprised one case of ureteric stenosis and one case of graft pyelonephritis. No late vascular complications or cases of incisional hernia were recorded.

CONCLUSION

Findings at 1-year follow-up indicate RAKT from a living donor to be a safe procedure in a properly selected group of recipients. RAKT was associated with a low complication rate and there was maintenance of excellent graft survival and function. This is the first and largest study to report functional results after RAKT from a living donor with a minimum follow-up of 1 year.

Value of perioperative genitourinary screening culture and colonization status in predicting early urinary tract infection after renal transplantation

Background

We aimed to assess whether patients colonized with certain organisms in the genitourinary tract would have greater urinary tract infection (UTI) risk during the post-transplantation period, and whether information on the perioperatively colonized organisms may help identify the causal organisms during early UTI.

Methods

We retrospectively reviewed the culture results of preoperative urine, preoperative urethral swab, and postoperative urinary catheter tip specimens of 420 renal transplant recipients. The colonization status was compared to the culture results during the first UTI episode within 6 months after transplantation.

Results

Twenty six (6.2%) patients developed early UTI, and the presence of common uropathogens in the perioperative genitourinary specimen was positively associated with a higher early UTI risk odds ratio [OR], 3.23; 95% confidence interval [CI], 1.44 to 7.24; P = 0.003). However, the actual causal organism during UTI was observed perioperatively only in 15 patients (40.5%). Neither perioperative colonization nor early UTI was associated with subsequent acute cellular rejection or graft failure.

Conclusions

Renal transplantation patients who were colonized with common uropathogens were more likely to develop early UTI. However, the usefulness of the culture results of perioperative colonizers in predicting the causal organism during early UTI seems limited due to the low concordance rate.

Prevalence and predictive factors of urinary tract infection among patients with stroke: A meta-analysis

BACKGROUND

Urinary tract infection (UTI) is thought to be a common complication of stroke and is regarded as a potential risk factor for poor stroke outcomes. However, there is a controversy among predictive factors of stroke-associated UTIs. We aim to estimate the prevalence and predisposing factors of UTIs among patients with stroke.

METHODS

PubMed, EMBASE, and Elsevier Science Direct were searched by 2 independent researchers. Sixteen studies with a total of 13,513 patients were included to evaluate the prevalence and predictive factors of stroke-associated UTIs published from the earliest records to March 10, 2017. Pooled effect sizes were calculated using the fixed effect model or random effect model according to I² and P values.

RESULTS

The pooled prevalence of UTI was 19.0% (95% confidence interval [CI], 15%-22%; P <.01). The predisposing factors for UTIs include female sex (odds ratio [OR], 1.93; 95% CI, 1.55-2.41), older age (OR, 1.28; 95% CI, 1.09-1.50), higher modified Rankin Scale score (OR, 1.90; 95% CI, 1.43-2.53), and postvoid residual volume >100 mL (OR, 3.69; 95% CI, 2.09-6.52).

CONCLUSIONS

Approximately one-fifth of patients with stroke contracted at least 1 UTI after cerebral apoplexy. Female sex, older age, higher modified Rankin Scale score, and postvoid residual volume >100 mL were associated with higher risk of UTI.

The challenge of urinary tract infections in renal transplant recipients

Urinary tract infections (UTI) are an important cause of morbidity and mortality in renal transplant patients. These infections are quite common, and the goal of care is to identify and reduce risk factors while providing effective prophylaxis and treatment. Better understanding of long-term outcomes from these infections has led to the distinctions among UTI, recurrent UTI, and asymptomatic bacteriuria (ASB), and that each requires a different therapeutic approach. Specifically, new research has supported the perspective that asymptomatic bacteriuria should not be treated. Symptomatic UTI, on the other hand, requires intervention and remains an ongoing challenge for infectious disease clinicians. Many bacteria species are responsible for UTI in renal transplant patients, and in recent years there has been a global rise in infection caused by bacteria with newly acquired antibacterial resistance genes. Many renal transplant patients who experience UTI will also have multiple recurring episodes, which likely has a distinct pathophysiological mechanism leading to chronic colonization of the urinary tract. In these cases, long-term management includes bacterial suppression, which aims to reduce rather than eliminate bacteria to levels below the threshold for symptomatic infection. This review will address the current understanding of UTI epidemiology, pathogenesis, and risk factors in the renal transplant community, and also focus on current prevention and treatment strategies for patients who face an environment of increasingly antibiotic-resistant bacteria.

The urine biomarker panel [IGFBP7]x[TIMP-2] (NephroCheck® parameter) does not correlate with IGFBP7 and TIMP-2 gene expression in urinary sediment

Background

Acute kidney injury (AKI) is frequently observed in serious infections, following nephrotoxic medication, surgery and trauma. Here we tested whether the detection of two recently identified biomarkers for AKI, Tissue Inhibitor of Metalloproteinase-2 (TIMP-2) and Insulin-Like Growth Factor Binding Protein 7 (IGFBP7), depends on the expression of these proteins in cells of the urinary sediment.

Method

We collected urine samples of 33 kidney transplant recipients and 14 non-transplanted patients who all had AKI (stages 1–3 according to KDIGO), and measured [IGFBP7]x[TIMP-2] using the NephroCheck^® Astute1 40 ^™ meter. Concomitantly, we analyzed IGFBP7 and TIMP-2 mRNA expression by quantitative polymerase chain reaction (qPCR) from urinary sediment of the same patients, and correlated the results with [IGFBP7]x[TIMP-2] (protein), by linear regression analysis. We also determined the association between [IGFBP7]x[TIMP-2] and estimated glomerular filtration rate (eGFR), and between IGFBP7 and TIMP-2 mRNA expression and markers of inflammation. Light microscopy and confocal immunofluorescence served to illustrate changes in the urinary sediment over the time course of renal function improvement.

Results

Of the 47 analyzed AKI patients, 14 presented with ascending urinary tract infection. Serum creatinine (sCr), blood urea nitrogen (BUN) and eGFR in all patients were 3.9±2.28 mg/dL, 47.59±23.1 mg/dL and 22.88±16.0 mL/min/1.73m², respectively, on average ±standard deviation. [IGFBP7]x[TIMP-2] was 2.33±9.95 (ng/ml)²/1000, and did not associate with IGFBP7 and TIMP-2 gene expression (r = -0.0220, p = 0.4216; respectively r = 0.0972, p = 0.1909). [IGFBP7]x[TIMP-2] did not associate with eGFR; IGFBP7 and TIMP-2 mRNA expression. Improvement of renal function went along with disappearance of casts, decrease in aquaporin1 positive renal epithelial cells and leukocytes from the urinary sediment.

Conclusion

The gene expression pattern of IGFBP7 and TIMP-2 from urinary sediment, which contains desquamated renal tubular epithelial cells, did not correlate with [IGFBP7]x[TIMP-2] protein, indicating that IGFBP7 and TIMP-2 measured in the NephroCheck^® test originated predominantly from intact but stressed cells of the kidney itself.

Male kidney allograft recipients at risk for urinary tract infection?

Background

Urinary tract infection (UTI) is the most common infection after renal transplantation (RTx). Although female sex is a well-known risk factor for the development of UTI after RTx, the role of the donor sex in this context remains unclear.

Methods

In this case control study 6,763 RTx cases were screened for UTI when presenting at our transplant outpatient clinics. 102 different RTx patients fulfilled the inclusion criteria and were compared to 102 controls. Data on renal function was prospectively followed for 12 months. Results were compared to a previous RTx cohort from our transplant center. Additionally, we assessed the immunological response of leukocytes from 58 kidney recipients and 16 controls to lipopolysaccharide stimulation.

Result

After identification by univariate analysis, multivariate logistic regression analysis indicated female sex, minor height, advanced age and male kidney allograft sex to be associated with the occurrence of UTI after RTx. Female recipients who received male grafts had the best renal function 12 months after presentation. However, leukocyte response of recipients to lipopolysaccharide was impaired irrespective of donor and recipient sex to the same extend.

Conclusions

We conclude from our data that male kidney allografts are associated with the occurrence of UTI after RTx but did not influence the response of leukocytes to lipopolysaccharide. Further prospective studies are needed to identify the underlying mechanisms of higher male kidney donor dependent UTI.

Risk Factors for Urinary Tract Infections in Renal Allograft Recipients: Experience of a Tertiary Care Center in Hyderabad, South India

Renal transplantation is an effective and commonly performed procedure for end-stage renal disease. Urinary tract infections are a major cause of morbidity and mortality in renal transplant patients. As data on postrenal transplant urinary tract infections from the Indian subcontinent are limited, the present study was conducted to estimate the burden of urinary tract infections in this vulnerable group of patients. This was a prospective study on patients undergoing renal transplantation in 2014 at our tertiary hospital in South India with a follow-up of 2 years to evaluate the risk factors for urinary tract infections. The prevalence of urinary tract infections was 41.9% with a male preponderance of 76.9%. Mean age of the 31 patients was 32.4 ± 10.2 years (range: 16-55 years). Gram-negative bacilli were the most common isolates with Escherichia coli being the predominant pathogen (53.3%). All the infections occurred within 1 year of transplantation with delayed graft function (P < 0.001; confidence interval [CI]: 29.0-96.3) and prolonged hospital stay (P = 0.0281; CI: 42.1-99.6) being the significant risk factors for acquiring urinary tract infections. Carbapenemase production was noted in 33.3% of isolates and all the Gram-negative organisms isolated in the 1st month of transplantation were carbapenem-resistant (CR) E. coli. The high rate of carbapenem-resistant organisms in the early posttransplant period is a point of concern, especially with cadaver transplants. Infection control practices and catheter care need to be strictly monitored to minimize the risk for UTI in the immediate posttransplant period.

Integrating MRI and Chemokine Receptor CXCR4-Targeted PET for Detection of Leukocyte Infiltration in Complicated Urinary Tract Infections After Kidney Transplantation

Complicated urinary tract infections (UTIs) are frequent in immunosuppressed patients after kidney transplantation and may lead to allograft failure or urosepsis. Noninvasive detection of allograft involvement as well as localization of the primary site of infection are challenging. Therefore, we sought to determine whether molecularly targeted PET, combined with diffusion-weighted MRI, enables detection of leukocytes in renal allografts. Methods: Thirteen kidney transplant recipients with complicated UTIs underwent both PET with a specific CXCR4 ligand, ⁶⁸Ga-pentixafor, and diffusion-weighted MRI. The spatial distribution and intensity of CXCR4 upregulation in renal allografts as determined by SUVs on PET and diffusion restriction as determined by apparent diffusion coefficients (ADCs) on MRI were analyzed and compared with urinalysis, clinical chemistry and bacteriology, and biopsy, if available. Results: Combined PET/MRI detected acute allograft infection in 9 patients and lower UTI/nonurologic infections in the remaining 4 patients. Leukocyte infiltration was identified by areas of CXCR4 upregulation compared with unaffected parenchyma in PET (SUV_mean, 4.6 vs. 3.7; P < 0.01), corresponding to areas with increased cell density in MRI (ADC_min, 0.89 vs. 1.59 × 10^-3 mm²/s, P < 0.01). Allograft CXCR4 signal was paralleled by CXCR4 upregulation in lymphoid organs. Histopathologic evaluation supported a correlation between CXCR4 signal and presence of leukocytes. Conclusion: Combined CXCR4-targeted PET/MRI with ⁶⁸Ga-pentixafor may enable the noninvasive detection of leukocytes in renal allografts. This novel methodology may refine the characterization of infectious and inflammatory kidney diseases and may serve as a platform for future clinical studies targeting allograft infection.

Thirty Years of Experience at the First Tunisian Kidney Transplant Center

OBJECTIVES

The aim of this study was to report the results of 30 years of experience at the first kidney transplant center in Tunisia.

MATERIALS AND METHODS

All kidney transplants performed at the center between June 1986 and June 2016 were included. The study period was divided into 3 decades. Recipient and donor data and follow-up information were obtained from a local database and patient medical records. Comparative analyses were performed using the t test for continuous variables and the Χ² test for qualitative variables. Patient and graft survival rates were calculated according to the actuarial method, and comparison of survival curves was performed according to the logrank test.

RESULTS

The mean age of recipients was 32.7 ± 11.5 years (range, 6-65 y) with a gender ratio of 2.2. Duration of prekidney transplant dialysis varied from 2 months to 20 years (median, 27.5 mo); 1.7% of patients underwent transplant preemptively. Kidneys were recovered from deceased donors in 21.2% of cases and from living donors in 78.8%. The proportion of deceased donors dropped from 27.4% during the period 2006-2010 to 12.9% during the period 2011-2015 (P < .04). Patient survival rates at 1, 5, 10, 15, and 20 years were 96%, 89.3%, 79.5%, 71.1%, and 65.4%. Graft survival rates were 95%, 86.5%, 76.2%, 66.3%, and 57.2%. The annual graft loss was 2.9%, with a mortality rate of 2.4% and without significant differences between patients receiving deceased-donor and living-donor organs.

CONCLUSIONS

Kidney transplant activity remains suboptimal in our country. The reduction in deceased-donor organs could be related to the political transformations facing our country with their resulting social and economic consequences. Efforts should be made to increase governmental resources and to improve both public awareness of organ donation and the motivation of transplant teams.