Evaluation of Infectious Complications in the First Year After Kidney Transplantation

Kidney Transplant-Associated Viral Infection Rates and Outcomes in a Single-Centre Cohort

BACKGROUND

Opportunistic infections remain a significant cause of morbidity and mortality after kidney transplantation. This retrospective cohort study aimed to assess the incidence and predictors of post-transplant DNA virus infections (CMV, EBV, BKV and JCV infections) in kidney transplant recipients (KTR) at a single tertiary centre and evaluate their impact on graft outcomes.

METHODS

KTR transplanted between 2000 and 2021 were evaluated. Multivariate logistic regression analysis and Cox proportional hazard analyses were used to identify factors associated with DNA virus infections and their impact on allograft outcomes respectively. A sub-analysis of individual viral infections was also conducted to describe the pattern, timing, interventions, and outcomes of individual infections.

RESULTS

Data from 962 recipients were evaluated (Mean age 47.3 ± 15 years, 62% male, 81% white). 30% of recipients (288/962) had infection(s) by one or more of the DNA viruses. Individually, CMV, EBV, BKV and JCV viruses were diagnosed in 13.8%. 11.3%, 8.9% and 4.4% of recipients respectively. Factors associated with increased risk of post-transplant DNA virus infection included recipient female gender, higher number of HLA mismatch, lower baseline estimated glomerular filtration rate (eGFR), CMV seropositive donor, maintenance with cyclosporin (rather than tacrolimus) and higher number of maintenance immunosuppressive medications. The slope of eGFR decline was steeper in recipients with a history of DNA virus infection irrespective of the virus type. Further, GFR declined faster with an increasing number of different viral infections. Death-censored graft loss adjusted for age, gender, total HLA mismatch, baseline eGFR and acute rejection was significantly higher in recipients with a history of DNA virus infection than those without infection (adjusted hazard ratio (aHR, 1.74, 95% CI, 1.08-2.80)). In contrast, dialysis-free survival did not differ between the two groups of recipients (aHR, 1.13, 95% CI, 0.88-1.47).

CONCLUSION

Post-transplant DNA viral infection is associated with a higher risk of allograft loss. Careful management of immunosuppression and close surveillance of at-risk recipients may improve graft outcomes.

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.

Incidence and Causes of Late Hospital Readmissions After Living Donor Renal Transplant: A Retrospective Study

OBJECTIVES

Our primary aim was to find the incidence, causes, and factors responsible for late hospital readmissions.

MATERIALS AND METHODS

There were 185 patients included in the study. The patients were divided into 2 groups: those with late readmission after discharge and those with no late readmission. Inpatient records and charts were assessed for the medical status of the patients, cause of chronic kidney disease, comorbidities, vintage and modality of dialysis, and hospital admissions 3 months before transplant. Collected patient data included recipient age, sex, height, weight, body mass index, hepatitis C status, donor age, methods of immunosuppression and induction, duration of hospital stay, postoperative complications and secondary procedures, number, duration, and causes of hospital readmission after transplant, and methods of evaluation and management during readmission.

RESULTS

There were 80 patients who received 127 late hospital readmissions. The most common cause of late hospital readmission was infection, which led to 45 admissions (35.43%). Of 45 admissions for infections, 18 were caused by urinary tract infections. Other reasons for admission were pneumonia (10 admissions), cytomegalovirus infection (11 admissions), and tuberculosis (6 admissions). The second most common cause of readmission was infectious or noninfectious diarrhea, which led to 29 admissions (22.88%). There were 28 late hospital readmissions (22.4%) for the evaluation or management of graft dysfunction. Newonset diabetes after transplant and febrile illness were causes of late hospital readmission in 8 cases each (6.9%), with 9 late hospital readmissions (7.08%) the result of other causes.

CONCLUSIONS

Incidence of late hospital readmission is high (43.2%), and the most common cause is infection, particularly urinary tract infections. Age of the recipient and early hospital readmission are predictive factors for late hospital readmission.

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.

Epidemiology, risk factors, and clinical impact of early post-transplant infection in older kidney transplant recipients: the Korean organ transplantation registry study

Background

As in younger recipients, post-transplant infection is a frequent and devastating complication after kidney transplantation (KT) in older recipients. However, few studies have analyzed characteristics of post-transplant infection in older kidney recipients. In this study of a nation-wide cohort of older kidney recipients, we investigated the current epidemiology, risk factors, and clinical impacts of early post-transplant infection, which was defined as infectious complications requiring hospitalization within the first 6 months after KT.

Methods

Three thousand seven hundred thirty-eight kidney recipients registered in the Korean Organ Transplantation Registry between 2014 and 2017 were enrolled. Recipients were divided into two groups, younger (n = 3081) and older (n = 657), with a cutoff age of 60 years. We observed characteristics of early post-transplant infection, and investigated risk factors for the development of infection. We also analyzed the association of early post-transplant infection with clinical outcomes including cardiac events, rejection, graft loss, and all-cause mortality.

Results

The incidence of early post-transplant infection was more frequent in older recipients (16.9% in younger group and 22.7% in older group). Bacteria were the most common causative pathogens of early post-transplant infection, and the most frequent site of infection was the urinary tract in both older and younger recipients. Older recipients experienced more mycobacterial infections, co-infections, and multiple site infections compared with younger recipients. In older recipients, female sex (HR 1.398, 95% CI 1.199–1.631), older donor age (HR 1.010, 95% CI 1.004–1.016), longer hospitalization after KT (HR 1.010, 95% CI 1.006–1.014), and experience of acute rejection (HR 2.907, 95% CI 2.471–3.419) were independent risk factors for the development of early post-transplant infection. Experiencing infection significantly increases the incidence of rejection, graft loss, and all-cause mortality.

Conclusion

Our results illustrate current trends, risk factors, and clinical impacts of early post-transplant infection after KT in older recipients. Considering the poor outcomes associated with early post-transplant infection, careful screening of recipients at high risk for infection and monitoring of recipients who experience infection are advised. In addition, since older recipients exhibit different clinical characteristics than younger recipients, further studies are needed to establish effective strategies for treating older recipients.

Supplementary Information

Supplementary information accompanies this paper at 10.1186/s12877-020-01859-3.

Epidemiology, Risk Factors, and Outcome of Bloodstream Infection Within the First Year After Kidney Transplantation

BACKGROUND

Multi-drug resistant organisms have been emerging among kidney transplant (KT) recipients with bloodstream infections (BSI). The investigation for epidemiology, risk factors and outcome of these infections following KT was initiated.

MATERIALS AND METHODS

A retrospective study of all adult KT recipients who developed a BSI within the first year after KT in 2016 at a single transplant center was conducted. The cumulative incidence of BSI was estimated with Kaplan-Meier methodology. Clinical characteristics and outcome were extracted. Risk factors were analyzed with Cox proportional hazards models.

RESULTS

Among 171 KT recipients, there were 26 (15.2%) episodes of BSI. Fifty-nine percent were men and the mean ± SD age was 43 ± 12 years. The cumulative incidence of BSIs was 10.1% at 1 month, 13.5% at 6 months, and 15.2% at 12 months. Gram-negative bacteria were responsible for 92% of BSIs, Escherichia coli was the most common pathogen (65%) followed by Klebsiella pneumoniae (11%). Among those, 71% were resistant to extended-spectrum cephalosporins. The genitourinary tracts were the predominant source of BSIs (85%). The second kidney transplantation (HR, 4.55; 95% CI, 1.24-16.79 [P = 0.02]) and receiving induction therapy (HR, 3.05; 95% CI, 1.15-8.10 [P < 0.03]) were associated with BSI in a multivariate analysis. One patient (4%) developed allograft rejection, allograft failure and death from septic shock.

CONCLUSIONS

One out of six KT recipients could develop BSI from gram-negative bacteria within the first year after transplant, particularly in those that received the second transplantation or induction therapy.

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.

Antibiotic therapy in case of positive cultures of kidney transplant preservation fluid: a nationwide survey of prescribing practices

Our survey aimed to describe current prescribing practices for perioperative antibiotic prophylaxis in French kidney transplant centers. We conducted a nationwide cross-sectional clinical vignette-based survey that we sent via email to hospital practitioners involved in perioperative management of kidney transplant patients (KTR). Nearly half of practitioners contacted (182/427, 42.6%) were respondents. A total of 167 getting enough kidney transplant activity were eligible for the survey. The response rate was 50.7% (68/134) among interns and 33.8% (99/293) among seniors. Positive perfusion fluids (PF) cultures for methicillin-susceptible Staphylococcus aureus were associated with antibiotic prescribing in 35% of cases, with no difference in prescribing in patients with diabetes, obesity, or delayed graft function. Antibiotic prescribing was most frequent with Pseudomonas aeruginosa (67%) and Klebsiella pneumoniae strains producing extended spectrum β-lactamases (57%). About 77%, 16%, and 13% of respondents, respectively, reported the existence of local practice guidelines for surgical antibiotic prophylaxis, a standardized approach for antibiotic prescribing in case of positive kidney transplant PF cultures, and local practice guidelines for systematical antibiotic prophylaxis in the early post-transplant period. In France, antibiotic prophylaxis practices in the perioperative kidney transplant period are very heterogeneous. To prevent unnecessary prescribing and bacterial resistance, evidence-based practice guidelines should be developed.

Gut uropathogen abundance is a risk factor for development of bacteriuria and urinary tract infection

The origin of most bacterial infections in the urinary tract is often presumed to be the gut. Herein, we investigate the relationship between the gut microbiota and future development of bacteriuria and urinary tract infection (UTI). We perform gut microbial profiling using 16S rRNA gene deep sequencing on 510 fecal specimens from 168 kidney transplant recipients and metagenomic sequencing on a subset of fecal specimens and urine supernatant specimens. We report that a 1% relative gut abundance of Escherichia is an independent risk factor for Escherichia bacteriuria and UTI and a 1% relative gut abundance of Enterococcus is an independent risk factor for Enterococcus bacteriuria. Strain analysis establishes a close strain level alignment between species found in the gut and in the urine in the same subjects. Our results support a gut microbiota–UTI axis, suggesting that modulating the gut microbiota may be a potential novel strategy to prevent UTIs.

Urinary tract infections (UTIs) are associated with changes in the gut microbiome. Here, the authors evaluate the relationship between the gut microbiome and development of UTI in kidney transplant patients and show that uropathogenic gut abundance might represent a risk factor for development of bacteriuria and UTI.

Risk factors and etiology of repeat infection in kidney transplant recipients

Kidney transplantation (KT) is the best therapy available for patients with end-stage renal disease, but postoperative infections are a significant cause of mortality.In this retrospective study the frequency, risk factors, causative pathogens, and clinical manifestations of infection in KT recipients from Beijing Chao-Yang Hospital, Capital Medical University were investigated. Ninety-seven KT recipients who were hospitalized with infection between January 2010 and December 2016 were included. Clinical characteristics, surgery details, laboratory results, and etiology were compared in patients who developed single infection and patients who developed repeated infection (2 or more) after KT.A total of 161 infections were adequately documented in a total of 97 patients, of which 57 patients (58.8%) had 1 infection, 24 (24.7%) had 2, 11 (11.3%) had 3; 3 (3.1%) had 4, and 2 (2.1%) had 5 or more. The most common infection site was the urinary tract (90 infections; 56%), both overall and in the repeated infection group. The most frequently isolated pathogen was Pseudomonas aeruginosa. In the repeated infection patients, in most cases of P. aeruginosa infection (54%) it was cultured from urine. For first infections, a time between KT and infection of ≤ 21 days (area under receiver operating characteristic curve [AUC] 0.636) and a tacrolimus level ≥ 8 ng/mL (AUC 0.663) independently predicted repeat infection. The combination of these two predictive factors yielded an AUC of 0.716, which did not differ statistically significantly from either predictor alone.With regard to first infections after KT, a time between KT and infection of ≤ 21 days, and a tacrolimus level ≥ 8 ng/mL each independently predicted repeated infection in KT recipients.

BK virus histopathologic disease severity does not predict allograft outcome in renal transplant recipients

AIMS

BK polyomavirus nephropathy (BKPyVN) is an important cause of allograft failure after renal transplantation. Despite early screening for the virus, allograft loss from BKPyVN is still experienced in up to 14% of all renal transplant recipients. The aim of this study was to investigate the association between BKPyVN histopathologic disease severity and allograft outcome at our center.

METHODS

Kidney transplant recipients who had undergone transplantation between 2002 and 2014 with biopsy proven BKPyVN were eligible for this retrospective study. Each biopsy was re-evaluated by a single pathologist blinded to the clinical data and scored according to the Banff criteria for rejection and BKPyVN. Serum creatinine and BK viral load at the time of biopsy diagnosis as well as allograft outcomes to include allograft survival and serum BK viremia resolution were collected for each recipient to determine if BK virus histopathologic disease severity could predict allograft outcome.

RESULTS

Twenty cases of BKPyVN were identified from 1031 total renal transplants performed. There was no statistical association between allograft loss and BKPyVN histopathology (p = 0.49). There was also no statistical association between BKPyVN histopathology and BK viral load at the time of biopsy diagnosis (p = 0.38) or serum BK viremia resolution (p = 0.16).

CONCLUSIONS

BKPyVN histopathology does not appear to be useful in predicting renal allograft outcome in those recipients diagnosed with BKPyVN which is in contrast to some previously published data.

Prevalence and Risk Factors of BK Viremia and Clinical Impact of BK Virus Surveillance on Outcomes in Kidney Transplant Recipients: A Single-Center Cross-Sectional Study

OBJECTIVES

BK virus is a polyomavirus that can cause nephropathy and graft loss after kidney transplant. The aim of our study was to screen the BK viremia prevalence, to understand the value of the inter-vention for BK virus nephropathy, and to determine the risk factors associated with BK viremia after kidney transplant in our center.

MATERIALS AND METHODS

Our retrospective cross-sectional study included 91 adult kidney transplant recipients who were seen between 2015 and 2017 and who had follow-up from 1 month to over 2 years. BK viremia was evaluated by use of plasma quantitative polymerase chain reaction. The prevalence of BK viremia and the clinical treatments and outcomes of BK virus nephropathy were assessed.

RESULTS

The prevalence of BK viremia was 5.5% (5/91 patients). BK virus nephropathy was confirmed by allograft biopsy in 4.4% (4/91 patients) of all patients. Delayed graft function was found to be an independent risk factor for BK viremia (P < .001). Patients with BK viremia had significantly higher serum creatinine levels (P = .04). Patients who were diagnosed with BK viremia at 1 to 5 years after kidney transplant had higher serum creatinine (P = .02) and uric acid levels (P = .02). After reduction or discontinuation of calcineurin inhibitor, BK virus was cleared in all patients with BK virus nephropathy, with higher level of serum creatinine but no graft loss.

CONCLUSIONS

Delayed graft function was considered as a risk factor for viremia. Early detection of BK viremia replication is important. The strategy of reduction of immunosuppression was effective for BK virus nephropathy and graft function improvement.

Risk of relapse of multiple myeloma following kidney transplantation

Background

Autologous stem cell transplantation (ASCT) and novel therapies have improved the prognosis for patients with multiple myeloma (MM). For those who undergo ASCT while on dialysis, a similar survival compared with the overall MM population has been reported. Therefore, for patients achieving remission following ASCT, kidney transplantation is an attractive option, offering an improved quality of life and significant economic advantage.

Method

This case series investigates the outcome of five patients who underwent an ASCT for MM with subsequent kidney transplantation between 2006 and 2012.

Results

Four patients presented with end-stage renal disease (ESRD) and one progressed to ESRD shortly after diagnosis. Induction chemotherapy regimens with novel agents including thalidomide and bortezomib were utilized. Following attainment of very good partial remission or complete remission, high-dose melphalan ASCTs were performed after a median of 10 months. Kidney transplantation (living donor n = 3, deceased donor n = 2) with tacrolimus-based immunosuppression regimens was completed at a median of 27 months after ASCT. Patients 1 and 3 experienced relapse of myeloma at 6 and 16 months after kidney transplantation. Patients 2, 4 and 5 remain alive at 55 months (median) after kidney transplantation with no evidence of relapse.

Conclusion

Forty percent of our cohort experienced a relapse in MM within 2 years of kidney transplantation. Death-censored graft survival and patient survival were 80% at 4 years. Our study adds to the growing literature supporting kidney transplantation following successful ASCT for MM and is useful when counselling patients regarding renal and haematological outcomes.

Human Vascular Pericytes and Cytomegalovirus Pathobiology

Pericytes are multipotent cells of the vascular system with cytoplasmic extensions proximal to endothelial cells that occur along the abluminal surface of the endothelium. The interactions between endothelial cells and pericytes are essential for proper microvascular formation, development, stabilization, and maintenance. Pericytes are essential for the regulation of paracellular flow between cells, transendothelial fluid transport, angiogenesis, and vascular immunosurveillance. They also influence the chemical composition of the surrounding microenvironment to protect endothelial cells from potential harm. Dysregulation or loss of pericyte function can result in microvascular instability and pathological consequences. Human pericytes have been shown to be targets for human cytomegalovirus (HCMV) infection and lytic replication that likely contribute to vascular inflammation. This review focuses on human vascular pericytes and their permissiveness for HCMV infection. It also discusses their implication in pathogenesis in the blood⁻brain barrier (BBB), the inner blood⁻retinal barrier (IBRB), the placenta⁻blood barrier, and the renal glomerulus as well as their potential role in subclinical vascular disease.

BK virus salivary shedding and viremia in renal transplant recipients

OBJECTIVES

This study aimed to verify the presence of polyomavirus BK (BKPyV) in the saliva of kidney transplant recipients and to correlate it with blood viremia.

MATERIAL AND METHODS

We have conducted a cross-sectional study with a sample involving 126 renal transplant recipients. 126 samples of saliva and 52 samples of blood were collected from these patients. Detection and quantification of BKPyV were performed using a real-time PCR. To compare the presence of BKPyV in blood and saliva, the binomial proportion test was used. To verify associations between salivary shedding BKPyV and post-transplant periods (in months), the Mann-Whitney test was used. Spearman's correlation was used to correlate the viral load in the saliva with blood of kidney transplant recipients.

RESULTS

The mean age of the study group was 51.11±12.45 years old, and 69 participants (54.8%) were female, with a mean post-transplantation time of 4.80±6.04 months. BKPyV was quantified in several samples of saliva and blood, with medians of 1,108 cp/mL and 1,255 cp/mL, respectively. Only 16/52 (30.8%) participants presented BKPyV in blood, and 59/126 (46.8%) excreted the virus in saliva (p=0.004). BKPyV shedding was found in patients at a shorter post-transplantation period (3.86±5.25, p=0.100). A weak correlation was observed between viral quantification in saliva and blood (Spearman's correlation coefficient=0.193).

CONCLUSION

The results of this study suggested that, although saliva excretes more BKPyV than blood, there is no reliable correlation between salivary shedding and blood viremia, showing two independent compartments of viral replication.

Evaluation of early and late-term infections after renal transplantation: Clinical experiences of Sanko University Medical Faculty Transplantation Center

OBJECTIVE

Infections play an important part in post-transplantation causes of morbidity and mortality. The purpose of this study is to evaluate short-, and long-term infections encountered in after renal transplantations.

MATERIAL AND METHODS

Two hundred and thirteen cases that consisted of both living and cadaver donors, who suffered from late period renal insufficiency and had renal transplant between June 2011 and January 2016 at the Transplantation Center of Sanko University School of Medicine were included in the study. In this study the short-, and long-term infections seen in post renal transplantation were examined retrospectively. Infection types, frequency and periods of infection, infection agents and predisposing factors were determined as the examination parameters.

RESULTS

Of the 213 patients who received renal transplant, 139 were males (65.3%) and 74 were women (34.75%) and the mean age was 42±11,8 (range, 14-70) years. Twelve (5.6%) patients exited after renal transplantation. Post-transplant infections were seen in 49 patients (23.1%) within 1-6 months; in 13 patients (6.1%) within 6-12 months; and in 5 patients (2.4%) after the 12^th month. The most common infections after renal transplantation were associated with urinary tract (70 patients, 34.3%). The most frequently isolated agents were E. coli (n=66; 30.9%), Kebsiella spp. (n=18; 8.4%) and Enterococci (n=18; 8.4%) respectively. The renal transplants from the cadavers were observed to contract infections 1.78 times more frequently compared to the living donors (OR=1.78, 95% CI=1.03-3.09).

CONCLUSION

The most common complication after renal transplantation are infections. The majority of the infections are seen within the first year especially between 1-6 months. Post-transplant infections are often related to urinary system. E.coli is the most frequently isolated agent and it may be responsible for urosepsis in renal transplant patients. Infection more often seen in renal transplantations from cadavers.

Epitope-Specific Humoral Responses to Human Cytomegalovirus Glycoprotein-B Vaccine With MF59: Anti-AD2 Levels Correlate With Protection From Viremia

The human cytomegalovirus (HCMV) virion envelope protein glycoprotein B (gB) is essential for viral entry and represents a major target for humoral responses following infection. Previously, a phase 2 placebo-controlled clinical trial conducted in solid organ transplant candidates demonstrated that vaccination with gB plus MF59 adjuvant significantly increased gB enzyme-linked immunosorbent assay (ELISA) antibody levels whose titer correlated directly with protection against posttransplant viremia. The aim of the current study was to investigate in more detail this protective humoral response in vaccinated seropositive transplant recipients. We focused on 4 key antigenic domains (AD) of gB (AD1, AD2, AD4, and AD5), measuring antibody levels in patient sera and correlating these with posttransplant HCMV viremia. Vaccination of seropositive patients significantly boosted preexisting antibody levels against the immunodominant region AD1 as well as against AD2, AD4, and AD5. A decreased incidence of viremia correlated with higher antibody levels against AD2 but not with antibody levels against the other 3 ADs. Overall, these data support the hypothesis that antibodies against AD2 are a major component of the immune protection of seropositives seen following vaccination with gB/MF59 vaccine and identify a correlate of protective immunity in allograft patients.

Mesangial cells, specialized renal pericytes and cytomegalovirus infectivity: Implications for HCMV pathology in the glomerular vascular unit and post-transplant renal disease

Background

Human Cytomegalovirus (HCMV) infection is problematic after kidney transplantation. Human mesangial cells along with human glomerular endothelial cells and podocytes constitute the renal glomerular vascular unit (GVU). HCMV infection of the GVU is poorly understood.

Methods

GVU cells infectivity was analysed by microscopy and immunofluorescence. Cytokines profiles were measured by Luminex assays. Renal tissue analysis for HCMV infection was performed by immunohistochemistry.

Results

Mesangial cells and glomerular endothelial cells but not podocytes were permissive for both lab adapted and clinical strains of HCMV. Luminex analysis of cytokines expressed by mesangial cells exposed to the SBCMV clinical strain was examined. A Tricell infection model of the GVU maintains >90% viability with a unique cytokine profile. Finally, we show αSMA stained mesangial cells permissive for HCMV in renal tissue from a transplant patient.

Conclusions

HCMV infection of mesangial cells induces angiogenic and proinflammatory cytokines that could contribute to glomerular inflammation.

Oral shedding of human herpesviruses in renal transplant recipients

OBJECTIVE

To describe the shedding profile of human herpesviruses in the saliva of renal transplant recipients.

METHODS

This is a prospective case-control study of 50 renal transplant recipients and control group of 50 individuals (non-transplanted and immunocompetent). Mouthwash samples were collected via oral rinse and then submitted to screening for the presence of eight types of herpesviruses by using multiplex PCR. Fisher's exact, chi-square, and Student t tests were used for statistical analysis, and the significance level was set at 5%.

RESULTS

The mean age of the study group was 49.42 ± 12.94 years, 28/50 (56%) were female, and the time elapsed after transplantation was 68.20 ± 67.19 months. Herpes simplex virus 1 (HSV-1) (P = 0.025) and Epstein-Barr virus (EBV) (P = 0.024) were, statistically, more excreted in the saliva of renal transplant recipients compared to control group. Gender (P = 1.00) and age (P = 0.563) did not influence the salivary shedding of herpesviruses in renal transplant recipients. Individuals who excreted varicella-zoster virus in saliva had a shorter mean time of transplantation (22:00 + 2.82 months) (P < 0.001).

CONCLUSION

Renal transplant recipients excreted herpesviruses more often than controls, especially HSV-1 and EBV, with salivary shedding of herpesviruses being more frequent in patients with recent kidney transplantation.

CLINICAL RELEVANCE

The present findings support other longitudinal studies evaluating the relationship between oral shedding of human herpesviruses and clinical presence of active infection and renal transplant failure.

Epidemiology of Infectious Complications in Renal Allograft Recipients in the First Year After Transplant

OBJECTIVES

Renal transplant is one of the best ways to extend life of patients in the end stage of renal disease. Infections are significant causes of morbidity and mortality after renal transplant. The aim of this study was to evaluate frequency, risk factors, causative pathogens, and clinical manifestations in renal transplant recipients from Mashhad City during the first year after transplant.

MATERIALS AND METHODS

This research was conducted at Montaserie Hospital of Mashhad University of Medical Sciences from March 2013 to July 2015. All studied cases were followed for 1 year. In this retrospective study, our study cohort comprised 193 kidney transplant recipients, including 118 male (61.1%) and 75 female (38.9%) patients, with mean age of 34.4 ± 12.2 years. Of the total patients, 58 received kidneys from living donors (30.1%) and 135 received kidneys from deceased donors (69.9%).

RESULTS

We found that 151 infectious episodes had occurred in 96 patients. The most common infectious site involved the urinary tract (39.1%). Escherichia coli was the most frequently isolated pathogen. The only significant infection risk factor to affect transplant outcomes during the first year was age.

CONCLUSIONS

Infections are highly prevalent during the first year after transplant. Prevention and effective antibiotic therapy can reduce the related adverse effects.

BK nephropathy in the native kidneys of patients with organ transplants: Clinical spectrum of BK infection

Nephropathy secondary to BK virus, a member of the Papoviridae family of viruses, has been recognized for some time as an important cause of allograft dysfunction in renal transplant recipients. In recent times, BK nephropathy (BKN) of the native kidneys has being increasingly recognized as a cause of chronic kidney disease in patients with solid organ transplants, bone marrow transplants and in patients with other clinical entities associated with immunosuppression. In such patients renal dysfunction is often attributed to other factors including nephrotoxicity of medications used to prevent rejection of the transplanted organs. Renal biopsy is required for the diagnosis of BKN. Quantitation of the BK viral load in blood and urine are surrogate diagnostic methods. The treatment of BKN is based on reduction of the immunosuppressive medications. Several compounds have shown antiviral activity, but have not consistently shown to have beneficial effects in BKN. In addition to BKN, BK viral infection can cause severe urinary bladder cystitis, ureteritis and urinary tract obstruction as well as manifestations in other organ systems including the central nervous system, the respiratory system, the gastrointestinal system and the hematopoietic system. BK viral infection has also been implicated in tumorigenesis. The spectrum of clinical manifestations from BK infection and infection from other members of the Papoviridae family is widening. Prevention and treatment of BK infection and infections from other Papovaviruses are subjects of intense research.