Post-transplant Bacterial Infections Research Articles

P-2257. Pseudomonas aeruginosa and other Bacterial Infections After Lung Transplant: Risk Factors, Airway Stenosis and other Clinical Outcomes

Abstract Background Pseudomonas aeruginosa (PsA) and other bacterial infections after lung transplant can lead to worse patient outcomes. The aim of this study was to investigate whether isolation of microbial pathogens post-lung transplantation increased the risk of airway stenosis requiring bronchoscopic interventions. Table 1Table 1.Demographic, donor/recipient characteristics, peri-operative/post-operative characteristics and outcomes. Methods A single-center retrospective study of lung transplant recipients (LTR) between January 2017 and October 2023 was performed. Our center performs routine surveillance bronchoscopies at 1, 3, 6 and 12 months. Donor/recipient characteristics, microbiologic data, bronchoscopy findings and interventions, and 1-year outcomes were analyzed. Results In this 6.8-year study period, 327 subjects underwent lung transplant with survival greater than 30 days. The most common indication for lung transplant was restrictive lung disease. 64 (20%) had PsA infections, 77 (23%) had non-PsA bacterial infections (infect), and 186 (57%) did not have a bacterial infection within 6-months post-transplant. Recipient and donor characteristics were similar among the cohorts. A greater proportion of the PsA and infect cohorts required dialysis and mechanical ventilation and/or ECMO for >48 hours and had a longer index hospitalization than the uninfected cohort [Table 1]. A greater proportion of the PsA and infect cohorts developed airway stenosis requiring bronchial intervention (22% vs 17% vs 2%, p=< 0.001). The median time to first infection post-transplant occurred prior to the development of stenosis (72 vs 112 days; 52 vs 110 days). 44% of LTR with PsA growth had fluoroquinolone resistance on the initial culture. Rates of rejection and 1-year survival were not statistically different among the cohorts. Conclusion PsA and other bacterial infections within the first 6-months post lung transplantation led to a higher incidence of airway stenosis requiring bronchial intervention but was not associated with increased mortality or rejection at 1-year. The impact of treating bacterial colonization and other strategies to minimize post-transplant bacterial infections and decreasing the occurrence and time to airway stenosis needs further study. Disclosures All Authors: No reported disclosures

Long-term outcomes and risk factors for early bacterial infection after pediatric liver transplantation: a prospective cohort study.

Liver transplantation (LT) is the most efficient treatment for pediatric patients with end-stage liver diseases, while bacterial infection is the leading reason for post-transplant mortality. The present study is to explore the outcomes and risk factors of early bacterial infection (within 1 months) after pediatric LT. In this prospective cohort study, 1316 pediatric recipients [median (IQR) age: 9.1 (6.3-28.0) months; male: 48.0%; median (IQR) follow-up time: 40.6 (29.1-51.4) months] who received LT from September 2018 to April 2022 were included. Bacterial culture samples such as sputum, abdominal drainage, blood, and so on were collected when recipients were presented with infective symptoms. Kaplan-Meier analysis was applied to estimate the long-term survival rates and logistic regression was used to identify independent risk factors. To explore the role of pretransplant rectal swab culture (RSC) in reducing post-transplant bacterial infection rate, 188 infant LT recipients [median (IQR) age: 6.8 (5.5-8.1) months; male: 50.5%] from May 2022 to September 2023 were included. Log-binomial regression was used to measure the association of pretransplant RSC screening and post-transplant bacterial infection. The 'Expectation Maximization' algorithm was used to impute the missing data. Bacterial infection was the primary cause for early (38.9%) and overall mortality (35.6%) after pediatric LT. Kaplan-Meier analysis revealed inferior 1-year and 5-year survival rates for recipients with post-transplant bacterial infection (92.6 vs. 97.1%, 91.8 vs. 96.4%, respectively; P <0.001). Among all detected bacteria, Staphylococcus spp. (34.3%) and methicillin-resistant coagulase-negative Staphylococci (43.2%) were the dominant species and multidrug resistant organisms, respectively. Multivariable analysis revealed that infant recipients [adjusted odds ratio (aOR) 1.49; 95% CI: 1.01-2.20], male recipients (aOR, 1.43; 95% CI: 1.08-1.89), high graft-to-recipient weight ratio (aOR, 1.64; 95% CI: 1.17-2.30), positive post-transplant RSC (aOR, 1.45; 95% CI: 1.04-2.02) and nasopharyngeal swab culture (aOR 2.46; 95% CI: 1.72-3.52) were independent risk factors for early bacterial infection. Furthermore, RSC screening and antibiotic prophylaxis before transplantation could result in a relatively lower post-transplant infection rate, albeit without statistical significance (adjusted RR, 0.53; 95% CI: 0.25-1.16). In this cohort study, post-transplant bacterial infection resulted in an inferior long-term patient survival rate. The five identified independent risk factors for post-transplant bacterial infection could guide the prophylaxis strategy of post-transplant bacterial infection in the future. Additionally, pretransplant RSC might decrease post-transplant bacterial infection rate.

Epidemiology and Risk Factors of Early Bacterial Infections After Pediatric Living Donor Liver Transplantation

Advancements in surgical techniques, immunosuppression regimens, and peri-operative and postoperative care have resulted in marked improvement in outcomes after pediatric living donor liver transplantation (PLDLT). Despite these developments, infectious complications remain a major cause of morbidity and mortality. This is a retrospective cohort analysis of pediatric recipients from January 2004 to December 2018. Patients were classified into infected and non-infected groups based on the occurrence of bacterial infection during the first 3 months after transplant. Perioperative risk factors for early post-transplant bacterial infections and postoperative outcomes were investigated. Seventy-two out of 221 children developed early bacterial infection (32.6%). The first episodes of bacterial infection most frequently occurred in the second week after LDLT (37.5%). In multivariate analysis, active infection before transplant and complications with Clavien-Dindo grading >3 were the only independent risk factors. Early bacterial infections were independently associated with longer intensive care unit stays, longer hospital stays, and a higher incidence of readmission for bacterial infection during the first year after transplant. Additionally, the overall patient survival rate was significantly higher in the non-infected group (P = .001). Risk factors for infection, such as age, weight, disease severity, ABO-incompatible, and other operative factors, were not identified as independent risk factors. We have demonstrated that there are similarities and disparities in the epidemiology and risk factors for early bacterial infection after transplant between centers. Identification and better characterization of these predisposing factors are essential in the modification of current preventive strategies and treatment protocols to improve outcomes for this highly vulnerable group.

2111. Impact of Colonization by Multi Drug Resistant Bacteria on Graft Survival, Risk of Infection, and Mortality in Recipients of Solid Organ Transplant: Systematic Review and Meta-analysis

Abstract Background Colonization with multi-drug resistant bacteria (MDR) in solid organ transplant (SOT) recipients increases the risk of post-transplant bacterial infection. MDR colonization impact on graft survival and mortality is not well established. Methods A search was executed by an expert librarian on PROSPERO, OVID Medline, Ovid EMBASE, Wiley Cochrane Library, ProQuest dissertations and Theses Global and SCOPUS, from inception until October 26, 2021. Adult SOT colonized with Methicillin resistant Staphylococcus aureus (MRSA), Vancomycin-resistant Enterococci (VRE), Extended-spectrum beta-lactamase (ESBL) or AmpC producing bacteria, carbapenem resistant Enterobacteriaceae (CRE), or MDR Pseudomonas were included and compared to non-colonized SOT. Pairs of reviewers screened abstracts and full studies for inclusion, and extracted data independently. We used RevMan to conduct a meta-analysis using random effects models to calculate the pooled risk ratio (RR) with 95% confidence interval (CI) for the incidence of infection, mortality, and graft failure. Statistical heterogeneity was determined using the I2 statistic. Figure-1 PRISMA chart, systemic review and metanalysis on Impact Of Colonization By Multi Drug Resistant Bacteria on Graft Survival, Risk of Infection, and Mortality in Recipients of Solid Organ Transplant. Results 59 articles spanning from 1989 to 2021 were included (Figure-1). Liver transplant (43 studies) and VRE colonization (17 studies) were the most common organ and MDR pathogen. MDR surveillance was performed by culture (71%) and PCR (6.7%). In liver transplant recipients, VRE and MRSA colonization were associated with increased infection risk, but not mortality (VRE infection: RR= 2.40 (95%CI 1.54-3.73; p&amp;lt; 0.001), I2= 66%; VRE mortality: RR= 1.64 (95%CI 0.88-3.05; p=0.12), I2= 44%; MRSA infection: RR= 4.07 (95%CI 2.66-6.24; p&amp;lt; 0.001), I2= 59%; MRSA mortality RR=1.47 (95%CI 0.79-2.76; p=0.23), I2= 35%). ESBL and CRE colonization were associated with increased risk of infection (ESBL: RR=9.87 (6.12-15.93); p&amp;lt; 0.001), I2=13%; CRE: RR= 13.64 (95%CI 5.73-32.47); p&amp;lt; 0.001), I2= 66%). CRE colonization was associated with increased mortality, RR=5.79 (95% CI 1.80-18.63; p=0.003), I2=0%. Conclusion While colonization with MRSA and VRE in liver transplant was not associated with increase mortality, CRE colonization was associated with almost 6-fold increased risk of death. These data should be taken into account when stratifying the risk of transplant. Disclosures Carlos Cervera, Associate Professor, Astra-Zeneca: Advisor/Consultant|AVIR Pharma: Grant/Research Support|AVIR Pharma: Honoraria|Lilly: Advisor/Consultant|Merck: Advisor/Consultant|Merck: Grant/Research Support|Merck: Honoraria|Sunovion: Advisor/Consultant|Takeda: Advisor/Consultant|Takeda: Honoraria|VerityPharma: Advisor/Consultant Dima Kabbani, MD, MSc, AVIR Pharma: Grant/Research Support|AVIR Pharma: Honoraria|GSK: Honoraria|Merck: Grant/Research Support.

Marijuana use and post-transplant complications and non-compliance in liver transplant patients

BackgroundLiver transplant (LT) is a lifesaving treatment for patients with end stage liver disease. Historically, institutions across the United States have deemed active marijuana use as an exclusion criterion for listing. This study aims to investigate LT outcomes in patients with history of marijuana use prior to LT. MethodsWe performed a retrospective review of 111 patients who tested positive for marijuana on urine drug screen during initial LT evaluation between February 2016 and January 2021. 100 non-marijuana users who underwent LT were cross matched for control. Patient demographics, substance use history, and transplant decisions were recorded. Post-LT variables were also collected up to 1 year post surgery including postoperative infections, issues with non-compliance, and continued substance use. Chi-square analysis was used to assess the association between pre-transplant marijuana use and post-transplant complications. Logistics regression was implemented to measure associations amongst the entire cohort. ResultsFrom 111 marijuana users, 32 (29%) received a transplant. There was no statistical difference in post-LT outcomes between marijuana and non-marijuana users, including incidence of cardiac, respiratory, renal, psychiatric, or neurological complications, as well as readmission rates post-surgery. There were no statistically significant associations between marijuana use with post-transplant bacterial or fungal infections, medication non-compliance, or continued substance use (all p>0.05). Marijuana use was associated with pre-LT tobacco use (p = 0.020). ConclusionsOur data indicates that marijuana is not associated with increased risk of postoperative noncompliance, other organ complications, infections, or death. As a single factor, marijuana may not need to be a contraindication for LT.

Reduced upper limb lean mass on dual energy X-ray absorptiometry predicts adverse outcomes in male liver transplant recipients.

BACKGROUNDPre-transplant muscle wasting measured by computed tomography has been associated with adverse clinical outcomes after liver transplantation including increased rates of sepsis and hospitalisation days. Upper limb lean mass (LM) measured by dual-energy X-ray absorptiometry (DEXA) was recently identified as a novel predictor of sarcopenia-associated mortality in men waitlisted for transplantation.AIMTo investigate the use of DEXA LM in predicting gender-stratified early post-transplant outcomes.METHODSLiver transplant recipients who underwent pre-transplant DEXA body composition imaging between 2002 and 2017 were included. Endpoints included post-transplant mortality and graft failure, bacterial infections, acute cellular rejection (ACR) and intensive care and total hospital length of stay.RESULTSFour hundred and sixty-nine patients met inclusion criteria of which 338 were male (72%). Median age was 55.0 years (interquartile range 47.4, 59.7) and model for end-stage liver disease (MELD) score 16. Median time from assessment to transplantation was 7 mo (3.5, 12). Upper limb LM was inversely associated with bacterial infections at 180 d post-transplant (hazard ratio = 0.42; 95% confidence interval: 0.20-0.89; P = 0.024) in males only. There was a negative correlation between upper limb LM and intensive care (τb = -0.090, P = 0.015) and total hospital length of stay (τb = -0.10, P = 0.0078) in men. In women, neither MELD nor body composition parameters were associated with post-transplant adverse outcomes or increased length of stay. Body composition parameters, MELD and age were not associated with 90-d mortality or graft failure in either gender. There were no significant predictors of early ACR.CONCLUSIONSarcopenia is an independent and potentially modifiable predictor of increased post-transplant bacterial infections and hospital length of stay in men with cirrhosis. DEXA upper limb LM provides a novel measure of muscle wasting that has prognostic value in this cohort. The lack of association in women requires further investigation.

Prevalence, risk factors and Impact of Post-transplant Tuberculosis on Live Donor Kidney Transplant Recipients: A Retrospective Study

Background: TB is encountered worldwide more frequently among renal transplant recipients than in the general population. It is reported to be nearly 50 times higher in the renal transplant population because of immunosuppression. TB may arise from unrecognized infection in the allograft or acquisition of new infection after transplantation. Objective: The aim of the current work was to determine prevalence and risk factors for development post-transplant TB, and the impact of post-transplant TB in live donor renal transplantation on both patient and graft survival. Patients and methods: This retrospective cohort study carried out in the Nephrology Unit, Mansoura Urology and Nephrology Centre in Association with Nephrology Unit, Zagazig University Hospitals in the period between January 2020 to December 2020. Included 210 patients out of 3200 kidney transplant recipients (KTRs) who underwent renal transplantation in the period between March 1976 and December 2019, divided into 2 main groups according to development of post-transplant tuberculosis, a group of 70 (KTRs) who developed tuberculosis after transplantation served as a study group and a matched group of 140 (KTRs) who did not develop tuberculosis after transplantation served as control group and evaluation of two groups through risk factor to develop TB, demographical data, clinical, laboratory and radiological evaluation. After that TB group was subdivided into 2 groups according to the site of infection: pulmonary and urinary TB. Results: Body mass index was higher among control group with statistically significant difference. Associated medical disorders as post-transplant diabetes, post-transplant bacterial and CMV infection had higher incidence among TB group. Liver enzymes and calcineurin (CNI) levels showed statistically significant difference among TB group before and during anti tuberculous treatment, in which liver enzymes were elevated while CNI levels were significantly reduced during antituberculous treatment. Post- transplant CMV infection was higher in patients who developed pulmonary TB. Graft and patient survival were comparable among both groups with no significant difference. Conclusions: It could be concluded that post-transplant diabetes, bacterial and CMV infections increase risk of development of post-transplant TB. There was no effect of post-transplant tuberculosis on both patient and graft survival.

MO987IMPACT OF POST-TRANSPLANT TUBERCULOSIS ON LIVE DONOR KIDNEY TRANSPLANT RECIPIENTS: RISK FACTORS AND OUTCOME

Abstract Background and Aims TB is encountered worldwide more frequently among renal transplant recipients due to of the state of immunosuppression. Antituberculosis drugs cause CYP-450 enzyme induction that increase the metabolism of CNI and mTORi So, decreasing the plasma trough level which in turn expose the transplant recipient to the risk of rejection. Our study concerned with the impact of post-transplant TB on live donor kidney transplant recipients outcome. Method This is retrospective cohort study held in Urology and Nephrology Center, Mansoura University, Egypt. The study included 210 patients out of 3200 kidney transplant recipients (KTRs) who underwent renal transplantation at Mansoura urology and Nephrology Centre between March 1976 and December 2019. The patients were divided into 2 main groups according to history of post-transplant tuberculosis, a group of 70 kidney transplant recipients who developed tuberculosis after transplantation served as a study group and a matched group of 140 kidney transplant recipients who did not develop tuberculosis after transplantation served as control group. Study group was then subdivided into pulmonary and urinary TB groups. Results We found that patients with Low BMI are associated with higher incidence of post-transplant TB (p value: 0.023). While, post-transplant TB was associated with increased incidence of post-transplant DM, bacterial infection, CMV infection and surgical wound infection. Exposure to rejection episodes (either acute or chronic) is comparable among both groups. Post-transplant diabetes incidence was higher among TB group with statistical significant difference (p value: 0.01). Bacterial infection incidence including pneumonia, urinary tract infection and gastroenteritis were associated with higher incidence of TB with statistically significant difference (p value: 0.012). CMV infection incidence was significantly higher among TB group (p value: 0.02). Incidence of wound infection post-transplantation was higher among TB group with statistically significant difference (p value: 0.014). Both groups were comparable regarding creatinine and creatinine clearance at last follow-up (p value: 0.61, 0.51 respectively). Overall, there was no statistically significant difference among both groups regarding 5, 10 and 15 years graft and patient survival (p value: 0.54, 0.15 respectively). During treatment of TB in the study group, there was statistical significant difference regarding liver enzymes and CNI doses either before or during anti-tuberculous treatment as liver enzymes were elevated (p value: 0.023) and higher doses of CNI were required to achieve satisfactory trough level during antituberculus treatment (p value: 0.037). Liver enzymes dropped significantly and lower doses of CNI were used after cessation of anti-tuberculous treatment (p value: 0.041, 0.03 respectively). Study group was then subdivided into 2 main groups: pulmonary TB (42 KTRs) and Urinary TB (28 KTRs). There was no statistical significant difference among both groups regarding baseline data, transplantation data, post-transplant medical complication except that CMV infection incidence was higher among pulmonary TB group (p value: 0.012). Patient and graft survival were comparable. Conclusion Among renal transplant recipients, tuberculosis is a serious problem for both the disease itself and its treatment with anti-tuberculous medications. In our series the rejection was comparable in both groups (with or without tuberculosis) this may be explained by frequent monitoring of the immunosuppressive drug level.

Pre- and post-transplant bacterial infections in liver transplant recipients.

Early (<1month) bacterial infection after liver transplant is a major cause of morbidity and mortality among liver transplant recipients. We investigated the impact of pre-transplant bacterial infection on early post-transplant bacterial infection incidence and outcomes. A retrospective cohort study identified all patients who underwent liver transplantation between January 1, 2011, and December 31, 2012, at a single tertiary center in the United States. Infections occurring within the 30days prior to transplant and within the 30 following transplant were identified. Information regarding pre-transplant morbidity and post-transplant outcomes was collected. One-hundred seventy-four patients were included in the study. Forty patients (23%) experienced a total of 50 pre-transplant infections. Fifty-two (30%) developed a total of 62 post-transplant infections. Patients with a pre-transplant infection were more likely to develop a post-transplant infection compared to patients without a pre-transplant infection (48% [19 of 40] vs. 25% [33 of 134], respectively, P=.006). Patients with a pre-transplant infection had a longer mean post-transplant length of stay compared to those without a pre-transplant infection (16.3days vs. 10.4days, respectively, P<.001), but survival at 30days was similar in both groups (95% [38 of 40] vs. 97% [130 of 134, respectively, P=.56). Among liver transplant recipients, pre-transplant infection is an important risk factor for early post-transplant bacterial infections. Pre-transplant infection is associated with increased early morbidity but not mortality after transplant.

Impact of MBL2 gene polymorphisms on the risk of infection in solid organ transplant recipients: A systematic review and meta-analysis.

Mannose-binding lectin (MBL) is a soluble pattern recognition molecule involved in complement activation. Single nucleotide polymorphisms (SNPs) in the MBL2 gene have been associated with susceptibility to infection, although data in solid organ transplant recipients remains inconclusive. This meta-analysis was primarily aimed at investigating the association between posttransplant bacterial and fungal infection and variant alleles of MBL2 gene SNPs in the promoter/5' untranslated region and exon 1. Cytomegalovirus (CMV) infection and/or disease were considered secondary outcomes. PubMed, EMBASE, and Web of Knowledge were searched for relevant articles up to August 2018. Eleven studies (comprising 1858 patients) were included, with liver transplant (LT) recipients accounting for 80.4% of the pooled population. As compared to high-MBL expression haplotypes (YA/YA, YA/XA), any MBL-deficient haplotype was associated with an increased risk of posttransplant bacterial and fungal infections (risk ratio [RR]: 1.30; P=.04). Low/null-MBL expression haplotypes (XA/O, O/O) also increased the risk of primary outcome (RR: 1.51; P=.008) and CMV events (RR: 1.50; P=.006). No effect was observed for individual promoter SNPs. In conclusion, MBL-deficient haplotypes are associated with a significant, albeit moderate, increase in the risk of posttransplant infection, with this association being mainly restricted to LT recipients.

265. Identification of Solid-Organ Transplant Antimicrobial Stewardship Opportunities in Pediatric Liver Transplant Patients

BackgroundThrough the prospective audit with feedback program, postoperative antimicrobial use for pediatric liver transplant was observed to extend beyond the recommended 24 hours for surgical site infection (SSI) prophylaxis. Bacterial infections in the immediate post-transplant period represent significant risk in pediatric liver-transplant recipients, including SSI. We describe our posttransplant antimicrobial (PTA) utilization in the largest pediatric liver transplant center to determine opportunities for the antimicrobial stewardship program (ASP).MethodsAll children who underwent a liver transplant between January 1, 2017 and September 30, 2017 at our institution were included. Antimicrobials initiated within 14 days posttransplant were captured, presence of fever within 14 days, positive microbiologic data within 30 days, and massive transfusion protocol (MTP) status were collected. The primary endpoint was duration of PTA. Clinical factors associated with PTA use >48 hours were evaluated.ResultsThirty-eight children underwent a liver transplant during the study period and 29 (76%) received a broad-spectrum Gram-negative (GN) antibiotic for > 48 hours posttransplant. Half of the patients received vancomycin and 15 (40%) received an antifungal posttransplant. Fever occurred in 21 (55%) of patients with a median onset of 1 day; 3 (8%) patients had a culture-proven posttransplant bacterial infection, with no resistant Gram-positive organisms identified. Eight patients (21%) met MTP and received PTA for ≥7 days and none had a positive bacterial culture. No differences were detected in fever or culture proven posttransplant infection between patients who received ≤48 hours of GN antibiotics compared with those who received >48 hours.ConclusionThe majority of children received PTA beyond 48 hours which was not attributable to prolonged posttransplant fevers or positive cultures. We identified ASP opportunities, including limiting GN antibiotics to 48 hours posttransplant, eliminating empiric vancomycin, restricting antifungals to MTP only, and limiting MTP PTA to 5 days.Disclosures All authors: No reported disclosures.

Ventricular assist devices as bridge to heart transplantation: impact on post-transplant infections.

BackgroundVentricular assist devices (VAD) are valuable options for patients with heart failure awaiting cardiac transplantation. We assessed the impact of pre-transplant VAD implantation on the incidence of post-transplant infections in a nationwide cohort of heart transplant recipients.MethodsHeart transplant recipients included in the Swiss Transplant Cohort Study between May 2008 and December 2012 were analyzed. Cumulative incidence curves were used to calculate the incidence of bacterial or Candida infections (primary endpoint) and of other infections (secondary endpoint) after transplant. Cox regression models treating death as a competing risk were used to identify risk factors for the development of infection after transplant.ResultsOverall, 119 patients were included in the study, 35 with a VAD and 84 without VAD. Cumulative incidences of post-transplant bacterial or Candida infections were 37.7 % in VAD patients and 40.4 % in non-VAD patients. In multivariate analysis, the use of cotrimoxazole prophylaxis was the only variable associated with bacterial/Candida infections after transplant (HR 0.29 [95 % CI 0.15-0.57], p < 0.001), but presence of a VAD was not (HR 0.94, [95 % CI 0.38-2.32], p = 0.89, for continuous-flow devices, and HR 0.45 [0.15 – 1.34], p = 0.15, for other devices). Risk for post-transplant viral and all fungal infections was not increased in patients with VAD. One-year survival was 82.9 % (29/35) in the VAD group and 82.1 % (69/84) in the non-VAD group. All 6 patients in the VAD group that died after transplant had a history of pre-transplant VAD infection.ConclusionIn this nationwide cohort of heart transplant recipients, the presence of VAD at the time of transplant had no influence on the development of post-transplant infections.Electronic supplementary materialThe online version of this article (doi:10.1186/s12879-016-1658-0) contains supplementary material, which is available to authorized users.

Vitamin D deficiency is associated with increased risk of bacterial infections after kidney transplantation.

Background/AimsThere may be an association between vitamin D levels and allograft outcomes in kidney transplant recipients (KTRs). However, few studies have been conducted to determine the association between vitamin D levels and post-transplant infections. This study investigated the impact of vitamin D deficiency on the risk of infection after kidney transplantation.MethodsWe measured 25-hydroxyvitamin D (25(OH)D) levels prior to kidney transplantation. Vitamin D deficiency was defined as a serum 25(OH)D level < 20 ng/mL. We examined the incidence of various post-transplant infections during follow-up period. We used Cox proportional hazards regression analysis to determine factors associated with increased risk of post-transplant infections during the follow-up period.ResultsA total of 164 KTRs were followed up for a mean of 24.8 ± 10.7 months. Among them, 135 patients (82.3%) had vitamin D deficiency. Patients with vitamin D deficiency had a significantly higher incidence of urinary tract infection (p = 0.027) and any bacterial infection (p = 0.010) compared to those without vitamin D deficiency. Vitamin D deficiency was not significantly associated with incidence of viral or fungal infections. Cox proportional hazards regression analysis revealed that vitamin D deficiency (hazard ratio, 11.07; 95% confidence interval, 1.46 to 84.03; p = 0.020) was independent risk factor for post-transplant bacterial infections.ConclusionsPre-transplant vitamin D deficiency was a significant risk factor for bacterial infections after kidney transplantation. Further studies are needed on possible benefits of vitamin D supplementation for preventing post-transplant bacterial infection.

Pretransplant Levels of Endotoxin Can Predict the Risk of Bacterial Infections and Graft Liver Function after Liver Transplantation

Although endotoxin (Et) has been used as a biological index of bacterial infections, Et can also be used to evaluate liver functions because Et present in the portal vein blood is processed by the hepatic reticuloendothelial system. In the field of posttransplant management, it is important for liver transplant recipients to monitor the presence of posttransplant bacterial infections and graft liver functions because these results are directly correlated with a graft prognosis. Therefore, the measurement of Et during liver transplantation (LT) may be the detection of posttransplant infections and graft liver functions. This retrospective study investigated whether Et measured by the Et activity assay (EAA) in the peripheral venous blood during living donor LT (LDLT) can predict the incidence of posttransplant bacterial infections and graft liver functions. The study subjects consisted of 21 patients who underwent LDLT between April 2010 and February 2011. Et activity (EA) was measured using the EAA in peripheral venous blood samples collected 1 or 2 days before LDLT, and on postoperative days (PODs) 1, 5, 7, and 14. We included LDLT recipients with intra-abdominal infections, respiratory infections, and bacteremia in the group with posttransplant bacterial infections. The incidence rates of posttransplant bacterial infections or hyperbilirubinemia after LDLT were 57.1%. The LDLT recipients with posttransplant bacterial infections or hyperbilirubinemia had significantly higher levels of EA in comparison with patients without complications before LDLT (0.22 ± 0.10 vs. 0.07 ± 0.05, p < 0.001), but they had no statistically significant increase of EA between PODs 1 and 14. Based on a receiver operating characteristic curve analysis of pretransplant levels of EA in patients with posttransplant bacterial infections or hyperbilirubinemia, the recommended cutoff value to diagnose posttransplant bacterial infections or hyperbilirubinemia was set at 0.16 (sensitivity 83.3%, specificity 88.9%, and area under the curve 0.940). At a pretransplant level of EA greater than 0.16, patients had an augmented risk for developing posttransplant bacterial infections or hyperbilirubinemia.

Decreased immunoglobulin G levels after living‐donor liver transplantation is a risk factor for bacterial infection and sepsis

Several studies have suggested an association between post-transplant immunoglobulin (Ig) levels and the development of infection in solid organ transplantation. We therefore conducted exploratory analyses of potential factors associated with bacterial infection/sepsis after living-donor liver transplantation (LDLT). Blood samples from 177 recipients who received primary LDLT between September 1999 and November 2011 were available for study. Hypogammaglobulinemia was defined as having at least 1 IgG level <650 mg/dL within 7 days after LDLT. Risk factors for developing post-transplant bacterial infection and sepsis within 3 months after LDLT were analyzed. Fifty (28.2%) recipients experienced bacterial infection within 3 months of LDLT. Eighty-four (47.5%) recipients had hypogammaglobulinemia, although no recipients had hypogammaglobulinemia before LDLT. Hypogammaglobulinemia, undergoing hepaticojejunostomy, and portal pressure at closure >15 mmHg were independent risk factors for developing bacterial infection within 3 months of LDLT (P < 0.0001 P = 0.0008, and P = 0.011, respectively). The odds ratio (OR) and confidence interval (CI) for hypogammaglobulinemia were 4.79 and 2.27-10.7, respectively. Twenty-four (13.6%) recipients developed bacterial sepsis within 3 months. Hypogammaglobulinemia, operative time >14 h, model for end-stage liver disease score >15, and no mycophenolate mofetil use were independent risk factors for developing bacterial sepsis (P = 0.009, P = 0.001, P = 0.003, and P = 0.005, respectively). The OR and CI for hypogammaglobulinemia were 3.83 and 1.38-12.0, respectively. Hypogammaglobulinemia within 7 days of LDLT was a significant risk factor for post-transplant bacterial infection and sepsis.

Bacterial infection after liver transplantation.

Infectious complications are major causes of morbidity and mortality after liver transplantation, despite recent advances in the transplant field. Bacteria, fungi, viruses and parasites can cause infection before and after transplantation. Among them, bacterial infections are predominant during the first two months post-transplantation and affect patient and graft survival. They might cause surgical site infections, including deep intra-abdominal infections, bacteremia, pneumonia, catheter-related infections and urinary tract infections. The risk factors for bacterial infections differ between the periods after transplant, and between centers. Recently, the emergence of multi-drug resistant bacteria is great concern in liver transplant (LT) patients. The instructive data about effects of infections with extended-spectrum beta lactamase producing bacteria, carbapenem-resistant gram-negative bacteria, and glycopeptide-resistant gram-positive bacteria were reported on a center-by-center basis. To prevent post-transplant bacterial infections, proper strategies need to be established based upon center-specific data and evidence from well-controlled studies. This article reviewed the recent epidemiological data, risk factors for each type of infections and important clinical issues in bacterial infection after LT.

Clinical Significance of Perioperative Prophylactic Antibiotics in Renal Transplantation

Introduction: Despite the advances in organ transplantation, the occurrence of infection remains a major cause of morbidity and mortality in renal transplant recipients. Although antimicrobial prophylactic regimens have become an integral part of medical therapy early after transplantation, the impact of the perioperative prophylactic antibiotics on the infectious complications following kidney transplantation has not been well studied. Methods: We retrospectively reviewed the medical records of 174 cases of renal transplantation performed at the Ajou University Medical Center from January 2006 to July 2010. The study population was divided into two different groups as follows, 70 patients with perioperative prophylactic antibiotic treatment; the other 104 patients without perioperative prophylactic antibiotic treatment. We analyzed the incidence of the various infectious complications within 1 month after renal transplantation with comparison between the groups. Results: We could not find any significant differences in patient demographic variables, such as age of recipient, donor source, gender, diabetes, and duration or modality of dialysis between the groups. We also could not find the statistically significant differences in the incidences of post-transplant bacterial infections during the hospital stays, including urinary tract infections (UTIs), surgical site infections (SSIs), surgical drain-related infections, and catheter-related bloodstream infections. Discussions: The results of this study demonstrate that prophylactic use of antibiotics could fail to make a difference in preventing the clinically evident bacterial infections, although renal transplantation is classified as a clean-contaminated surgery. To prevent bacterial infection after kidney transplantation, the other preventive measures such as intensive skin preparation, aseptic technique during surgery, copious irrigations into the urinary bladder before open, clean environment in the surgery room would be more important than the use of antibiotics.

Rates of first infection following kidney transplant in the United States

We studied the incidence, trends and clinical correlates of infections following kidney transplantation in the United States Renal Data System over the years 1995-2003 in 46,471 adults with Medicare primary coverage at the time of their first kidney transplant. The incidence of most infections has declined only slightly since 1995 but infection with cytomegalovirus significantly declined while that with hepatitis C significantly increased. Relative frequencies of different types of infections (bacterial, viral, fungal and parasitic) were relatively constant, both during early and late periods following transplant. Using the Cox proportional hazards analysis we found that the clinical correlates for post-transplant bacterial and viral infections included older age, female gender, diabetes as the cause of end-stage renal disease, deceased (vs. living) donor source, time on dialysis before transplant, hepatitis B and C viral pre-transplant serologic status and pre-transplant donor-recipient cytomegalovirus serology. Our study shows that despite identifiable risk factors, the incidence of most post-transplant infections has changed little since 1995.

Impact of Pretransplant Neutropenia on Post-Transplant Outcome in Patients with Myelodysplastic Syndrome (MDS).

MDS comprises a spectrum of clonal hematopoietic disorders with very heterogeneous clinical courses. Several classification and scoring systems have been developed in an attempt to define subgroups of patients with similar prognoses. The International Prognostic Scoring System (IPSS) incorporates marrow myeloblast count, karyotype, and peripheral blood cytopenias. The recent addition of transfusion requirements to the IPSS (WPSS) has sharpened this prognostic tool. Isolated neutropenia is not reflected in these classifications, but bacterial and fungal colonization and infection are problems in patients with MDS. Hematopoietic cell transplantation is the only treatment strategy that has been shown to have curative potential, and many patients come to transplantation with neutropenia, particularly when the disease progresses. We wanted to determine the impact of neutropenia before transplantation on transplant success. We reviewed results in 291 patients with MDS (including MDS that had transformed to AML [tAML]), 1 to 66 (median 50) years of age, who from 1994 through 2003 were transplanted from related or unrelated donors following conditioning with myeloablative regimens. There were 178 patients (61%) who had neutropenia, defined as <1,500/microliter; in 16 of these (9%) neutropenia was an isolated finding. Among the 178 patients, 137 (47%) had neutrophil counts below 1,000, and 86 (30%) below 500. Patients with neutropenia following recent chemotherapy were excluded. The risk of clinically relevant bacterial infections after transplantation was significantly increased in patients with neutropenia (p=0.001). Neutropenic patients had an increased risk for infections with gram-positive (relative risk [RR] 1.77, p=0.02), but not gram negative bacteria (RR 1.33, p=0.53). Specific organisms for which the RR was significantly increased included coagulase negative Staphylococcus, Bacillus species and Corynebacterium spp., suggesting that at least part of this risk was associated with intravascular catheters. The RR for invasive fungal infections (Candida and Aspergillus spp.) was 2.56 (p=0.03) for patients with <1,500 neutrophils. The hazard rate (HR) for non-relapse mortality by day 100 (21%) was 1.8 (p=0.03), and by 5 years (42%) was 1.62 (p=0.01). The most frequent causes of death were infections. The HR for 5-year mortality was 1.55 (p=0.007) for neutropenic patients. The pattern for the small group of patients with isolated neutropenia was identical to that for all patients with neutropenia. Pre-transplant neutropenia had no significant impact on engraftment or graft-versus-host disease. The probability of survival did not differ significantly between patients with IPSS scores of 0 and 0.5 with isolated or multiple cytopenias. In summary, only few patients with MDS who undergo transplantation have isolated neutropenia. However, pre-transplant neutropenia in patients with MDS is associated with a significantly increased risk of posttransplant bacterial infections, fungal infections, and non-relapse mortality, and a decreased probability of survival after myeloablative transplantation. A correlation with pre-transplantation colonization remains to be determined. Intensified and possibly extended antibiotic coverage should be considered.

Nosocomial Infection in Kidney Transplant Recipients: A Retrospective Analysis of a Single-Center Experience

Posttransplant bacterial infections are important because of their influence on patient and graft outcomes. Therefore, prevention of infection as well as prompt diagnosis and appropriate treatment are crucial. In this retrospective analysis, we reviewed all posttransplant bacterial infections occurring during the admission of kidney transplant patients from January 2000 to May 2004. Of our patients, 25% had at least one episode of infection. Patients with immunosuppression based on an mTOR inhibitor showed the highest rate of wound infections compared to those receiving a calcineurin inhibitor (odds ratio 5.6, P < .001). Patients with renal failure caused by a urologic disease revealed a increased risk of a urinary tract infections (odds ratio 5.9, P < .001). Although infection complications are an important cause of morbidity in renal transplantation, the extensive use of antibiotics should be avoided in favor of a strict policy for infection prevention and control.