Severe infections requiring intensive care unit admission in kidney transplant recipients: impact on graft outcome

Efficacy and safety of carrimycin in ten patients with severe pneumonia following solid organ transplantation

BACKGROUND

The number of patients undergoing solid organ transplantation has increased annually. However, infections in solid organ transplant recipients can have a severe effect on patient survival owing to the continued use of immunosuppressants. Carrimycin is a novel macrolide antibiotic produced by genetically engineered streptomyces spiramyceticus harboring a 4''-O-isovaleryltransferase gene (ist) from streptomyces thermotoleran. Carrimycin has good antibacterial and antiviral effects. However, no relevant studies have been conducted on the efficacy and safety of carrimycin in patients with severe pneumonia (SP) after solid organ transplantation.

AIM

To explore the efficacy and safety of carrimycin in patients with SP after solid organ transplantation to provide a medication reference for clinical treatment.

METHODS

In March 2022, ten patients with SP following solid-organ transplantation were treated at our hospital between January 2021 and March 2022. When the condition was critical and difficult to control with other drugs, carrimycin was administered. These ten patients' clinical features and treatment protocols were retrospectively analyzed, and the efficacy and safety of carrimycin for treating SP following solid organ transplantation were evaluated.

RESULTS

All ten patients were included in the analysis. Regarding etiological agent detection, there were three cases of fungal pneumonia, two cases of bacterial pneumonia, two cases of Pneumocystis pneumonia, and three cases of mixed infections. After treatment with carrimycin, the disease in seven patients significantly improved, the course of the disease was significantly shortened, fever was quickly controlled, chest computed tomography was significantly improved, and oxygenation was significantly improved. Finally, the patients were discharged after curing. One patient died of acute respiratory distress syndrome, and two patients discontinued treatment.

CONCLUSION

Carrimycin is a safe and effective treatment modality for SP following solid organ transplantation. Carrimycin may have antibacterial and antiviral effects in patients with SP following solid organ transplantation.

Can the pan-immune-inflammation value predict gram negative bloodstream infection-related 30-day mortality in solid organ transplant patients?

BACKGROUND

The recently used pan-immune-inflammation value (PIV) has not been adequately studied as a predictive marker for mortality in immunosuppressed patients. The aim of this study was to evaluate the usefulness of baseline PIV level as a predictor of 30-day mortality in solid organ transplant (SOT) recipients with gram negative bloodstream infections (GN-BSI).

METHODS

This retrospective, cross-sectional study was conducted between January 1, 2019, and December 31, 2022, in 1104 SOT recipients. During the study period, 118 GN-BSI were recorded in 113 patients. Clinical, epidemiological, and laboratory data were collected, and mortality rates (30-day and all-cause) were recorded.

RESULTS

The 113 recipients had a median age of 50 years [interquartile range (IQR) 37.5-61.5 years] with a male predominance (n = 72, 63.7%). The three most common microorganisms were as follows: 46 isolates (38.9%) of Escherichia coli, 41 (34.7%) of Klebsiella pneumoniae, and 12 (10.2%) of Acinetobacter baumannii. In 44.9% and 35.6% of the isolates, production of extended-spectrum beta-lactamases and carbapenem resistance were detected, respectively. The incidence of carbapenem-resistant GN-BSI was higher in liver recipients than in renal recipients (n = 27, 69.2% vs n = 13, 17.6%, p < 0.001). All-cause and 30-day mortality rates after GN-BSI were 26.5% (n = 30), and 16.8% (n = 19), respectively. In the group with GN-BSI-related 30-day mortality, the median PIV level was significantly lower (327.3, IQR 64.8-795.4 vs. 1049.6, IQR 338.6-2177.1; p = 0.002). The binary logistic regression analysis identified low PIV level [hazard ratio (HR) = 0.93, 95% confidence interval (CI) 0.86-0.99; p = 0.04], and increased age (HR = 1.05, 95% CI 1.01-1.09; p = 0.002) as factors associated with 30-day mortality. The receiver operating characteristic analysis revealed that PIV could determine the GN-BSI-related 30-day mortality with area under curve (AUC): 0.723, 95% CI 0.597-0.848, p = 0.0005.

CONCLUSIONS

PIV is a simple and inexpensive biomarker that can be used to estimate mortality in immunosuppressed patients, but the results need to be interpreted carefully.

Severe Community-Acquired Pneumonia in Immunocompromised Patients

Due to higher survival rates with good quality of life, related to new treatments in the fields of oncology, hematology, and transplantation, the number of immunocompromised patients is increasing. But these patients are at high risk of intensive care unit admission because of numerous complications. Acute respiratory failure due to severe community-acquired pneumonia is one of the leading causes of admission. In this setting, the need for invasive mechanical ventilation is up to 60%, associated with a high hospital mortality rate of around 40 to 50%. A wide range of pathogens according to the reason of immunosuppression is associated with severe pneumonia in those patients: documented bacterial pneumonia represents a third of cases, viral and fungal pneumonia both account for up to 15% of cases. For patients with an undetermined etiology despite comprehensive diagnostic workup, the hospital mortality rate is very high. Thus, a standardized diagnosis strategy should be defined to increase the diagnosis rate and prescribe the appropriate treatment. This review focuses on the benefit-to-risk ratio of invasive or noninvasive strategies, in the era of omics, for the management of critically ill immunocompromised patients with severe pneumonia in terms of diagnosis and oxygenation.

Management of Immunosuppressive Therapy in Kidney Transplant Recipients with Sepsis: A Multicenter Retrospective Study

BACKGROUND

Up to 6% of kidney transplant recipients (KTRs) experience life-threatening complications requiring intensive care unit (ICU) admission, and one of the most common medical complications requiring ICU admission is infection. This study aimed to evaluate the effect of immunosuppressive therapy (IST) modification on prognosis of KTRs with sepsis.

METHODS

We conducted a multicenter retrospective study in 4 university-affiliated hospitals to evaluate the effect of adjusting the IST in KTRs with sepsis. Only patients who either maintained IST after ICU admission or those who underwent immediate (within 24 h of ICU admission) reduction or withdrawal of IST following ICU admission were included in this study. "Any reduction" was defined as a dosage reduction of any IST or discontinuation of at least 1 IST. "Complete withdrawal of IST" was defined as concomitant discontinuation of all ISTs, except steroids.

RESULTS

During the study period, 1596 of the KTRs were admitted to the ICU, and 112 episodes of sepsis or septic shock were identified. The overall in-hospital mortality rate was 35.7%. In-hospital mortality was associated with higher sequential organ failure assessment score, simplified acute physiology score 3, non-identical human leukocyte antigen relation, presence of septic shock, and complete withdrawal of IST. After adjusting for potential confounding factors, complete withdrawal of IST remained significantly associated with in-hospital mortality (adjusted coefficient, 1.029; 95% confidence interval, 0.024-2.035) and graft failure (adjusted coefficient, 2.001; 95% confidence interval, 0.961-3.058).

CONCLUSIONS

Complete IST withdrawal was common and associated with worse outcomes in critically ill KTRs with sepsis.

Management of the kidney transplant recipient in the intensive care unit

PURPOSE OF REVIEW

Kidney transplantation is the ideal treatment for patients with chronic kidney disease and end stage renal disease. While centers are performing more transplants every year, the need for organ transplantation outpaces the supply of organ donors. Due to a growing population of patients with advanced kidney disease and a scarcity of kidneys from deceased donors, patients face extended wait times. By the time patients approach transplantation they have multiple comorbidities, in particular cardiovascular complications. Their risk of complications is further compounded by exposure to immunosuppression post kidney transplantation. Kidney transplant recipients (KTRs) are medically complex and may require acute management in the intensive care unit (ICU), as a result of cardiovascular complications, infections, and/or respiratory compromise from lung infections and/or acute pulmonary edema. Acute complication of immunosuppression, such as thrombotic microangiopathy and posterior reversible encephalopathy syndrome may also warrant ICU admission. This review will cover assessment of high-risk complications and management strategies following kidney transplantation.

RECENT FINDINGS

For intensivists caring for KTRs, it is imperative to understand anatomical considerations of the transplanted kidney, unique infectious risks faced by this population, and appropriate modulation of immunosuppression.

SUMMARY

Recognizing potential complications and implementing appropriate management strategies for KTRs admitted to the ICU will improve kidney allograft and patient survival outcomes.

Acute Kidney Injury in Kidney Transplant Patients in Intensive Care Unit: From Pathogenesis to Clinical Management

Kidney transplantation is the first-choice treatment for end-stage renal disease (ESRD). Kidney transplant recipients (KTRs) are at higher risk of experiencing a life-threatening event requiring intensive care unit (ICU) admission, mainly in the late post-transplant period (more than 6 months after transplantation). Urosepsis and bloodstream infections account for almost half of ICU admissions in this population; in addition, potential side effects related to immunosuppressive treatment should be accounted for cytotoxic and ischemic changes induced by calcineurin inhibitor (CNI), sirolimus/CNI-induced thrombotic microangiopathy and posterior reversible encephalopathy syndrome. Throughout the ICU stay, Acute Kidney Injury (AKI) incidence is common and ranges from 10% to 80%, and up to 40% will require renal replacement therapy. In-hospital mortality can reach 30% and correlates with acute illness severity and admission diagnosis. Graft survival is subordinated to baseline estimated glomerular filtration rate (eGFR), clinical presentation, disease severity and potential drug nephrotoxicity. The present review aims to define the impact of AKI events on short- and long-term outcomes in KTRs, focusing on the epidemiologic data regarding AKI incidence in this subpopulation; the pathophysiological mechanisms underlying AKI development and potential AKI biomarkers in kidney transplantation, graft and patients' outcomes; the current diagnostic work up and management of AKI; and the modulation of immunosuppression in ICU-admitted KTRs.

Impact of a Dedicated Pretransplant Infectious Disease Consultation on Respiratory Tract Infections in Kidney Allograft Recipients: A Retrospective Study of 516 Recipients

BACKGROUND

Respiratory tract infections (RTIs) are a leading cause of death after kidney transplant. Preventive strategies may be implemented during a dedicated infectious disease consultation (IDC) before transplantation. Impact of IDC on RTIs after transplant has not been determined.

METHODS

We conducted a monocentric retrospective cohort analysis including all kidney transplant recipients from January 2015 to December 2019. We evaluated the impact of IDC on RTIs and identified risk and protective factors associated with RTIs.

RESULTS

We included 516 kidney transplant recipients. Among these, 145 had an IDC before transplant. Ninety-five patients presented 123 RTIs, including 75 (61%) with pneumonia. Patient that benefited from IDC presented significantly less RTIs (p = 0.049). RTIs were an independent risk factor of mortality (HR = 3.64 (1.97-6.73)). Independent risk factors for RTIs included HIV (OR = 3.33 (1.43-7.74)) and HCV (OR = 3.76 (1.58-8.96)). IDC was identified as an independent protective factor (OR = 0.48 (0.26-0.88)). IDC prior to transplantation is associated with diminished RTIs and is an independent protective factor. RTIs after kidney transplant are an independent risk factor of death. Implementing systematic IDC may have an important impact on reducing RTIs and related morbidity and mortality.

Gram-negative bacteremia in solid organ transplant recipients: Clinical characteristics and outcomes as compared to immunocompetent non-transplant recipients

BACKGROUND

Outcomes from Gram-negative bacteremia (GNB) in solid organ transplant (SOT) recipients are poorly understood.

METHODS

This is a single center prospective cohort study comparing the clinical characteristics and outcomes of SOT recipients with GNB to immunocompetent non-SOT patients with GNB between 1/1/2002 through 12/31/2018. Outcomes of interest included incidence of septic shock, respiratory failure, and time to death. A multivariable logistic regression model was used to determine factors associated with incidence of septic shock and respiratory failure. Time to death was evaluated using Cox proportional hazard models.

RESULTS

A total of 297 SOT and 1245 immunocompetent non-SOT patients were included. Incidence of septic shock did not significantly differ between the groups (SOT 25.3% vs. non-SOT 24.6%, p = .8225). Overall survival did not significantly differ by transplant status (30-day survival: SOT 76%, 95% confidence interval [CI] 70, 92, non-SOT 74%, 95% CI 71, 77: log rank: p = .76). SOT recipients taking three immunosuppressive medications had significantly lower odds of developing septic shock or respiratory failure requiring intubation and mechanical ventilation than those taking ≤1 agent (shock: adjusted odds ratio [aOR] 0.29, 95% CI 0.09, 0.90, p = .0316; respiratory failure: aOR 0.14, 95% CI: 0.04, 0.49, p = .0020).

CONCLUSIONS

SOT recipients with GNB do not experience higher rates of septic shock, respiratory failure, or mortality than immnon-SOT recipients with GNB. Among SOT recipients, a greater number of immunosuppressive medications may be associated with improved outcomes during GNB. Future studies are needed to understand the potential relationship between levels of immunosuppression and clinical outcome in SOT recipients with GNB.

Sepsis affects kidney graft function and one-year mortality of the recipients in contrast with systemic inflammatory response

Background

Infections remain a major cause of morbidity and mortality after kidney transplantation. The aim of our study was to determine the effect of sepsis on kidney graft function and recipient mortality.

Methods

A prospective, observational, single-center study was performed. Selected clinical and biochemical parameters were recorded and compared between an experimental group (with sepsis, n = 34) and a control group (with systemic inflammatory response syndrome, n = 31) comprising kidney allograft recipients.

Results

Sepsis worsened both patient (HR = 14.77, p = 0.007) and graft survival (HR = 15.07, p = 0.007). Overall one-year mortality was associated with age (HR = 1.08, p = 0.048), APACHE II score (HR = 1.13, p = 0.035), and combination immunosuppression therapy (HR = 0.1, p = 0.006), while graft survival was associated with APACHE II (HR = 1.25, p = 0.004) and immunosuppression. In sepsis patients, mortality correlated with the maximal dose of noradrenalin (HR = 100.96, p = 0.008), fungal infection (HR = 5.64, p = 0.024), SAPS II score (HR = 1.06, p = 0.033), and mechanical ventilation (HR = 5.97, p = 0.033), while graft survival was influenced by renal replacement therapy (HR = 21.16, p = 0.005), APACHE II (HR = 1.19, p = 0.035), and duration of mechanical ventilation (HR = 1.01, p = 0.015).

Conclusion

In contrast with systemic inflammatory response syndrome, septic kidney allograft injury is associated with early graft loss and may represent a significant risk of mortality.

Visceral Leishmaniasis After Kidney Transplant: An Unusual Presentation and Mode of Diagnosis

Infection caused by Leishmania species has been increasingly reported in solid-organ transplant recipients since the first case report in 1979. Visceral leishmaniasis is endemic in central and eastern regions of India. Clinical features may simulate a variety of other infections, and a high index of suspicion is required for the diagnosis. Early diagnosis of this endemic infection is likely to result in improved outcome. We describe an unusual presentation of leishmaniasis in a kidney allograft recipient with organomegaly and pancytopenia sans fever detected by isolation of amastigotes in duodenal biopsy. To the best of our knowledge, this is the first case report of this kind in a kidney transplant recipient.

Survival Outcome of Sepsis in Recipients of Solid Organ Transplant

Sepsis is a complex disease stemming from a dysregulated immune response toward an infectious agent. In transplantation, sepsis remains one of the leading causes of morbidity and mortality. Solid organ transplant recipients have impaired adaptive immunity due to immunosuppression required to prevent rejection. Immunosuppression has unintended consequences, such as increasing the risk of infections and sepsis. Due to its high morbidity and mortality, early detection of sepsis is paramount to start aggressive treatment. Several biomarkers or combination of biomarkers of sepsis have emerged in the last decade, but they are not dependable for early diagnosis or for outcome prognosis.

Bacteremia in solid organ transplant recipients as compared to immunocompetent patients: Acute phase cytokines and outcomes in a prospective, matched cohort study

We undertook a prospective, matched cohort study of patients with Staphylococcus aureus bacteremia (SAB) and gram-negative bacteremia (GNB) to compare the characteristics, outcomes, and chemokine and cytokine response in transplant recipients to immunocompetent, nontransplant recipients. Fifty-five transplant recipients (GNB n = 29; SAB n = 26) and 225 nontransplant recipients (GNB n = 114; SAB n = 111) were included for clinical analysis. Transplant GNB had a significantly lower incidence of septic shock than nontransplant GNB (10.3% vs 30.7%, p = .03). Thirty-day mortality did not differ significantly between transplant and nontransplant recipients with GNB (10.3% vs 15.8%, p = .57) or SAB (0.0% vs 11.7%, p = .13). Next, transplant patients were matched 1:1 with nontransplant patients for the chemokine and cytokine analysis. Five cytokines and chemokines were significantly lower in transplant GNB vs nontransplant GNB: IL-2 (median [IQR]: 7.1 pg/ml [7.1, 7.1] vs 32.6 pg/ml [7.1, 88.0]; p = .001), MIP-1β (30.7 pg/ml [30.7, 30.7] vs 243.3 pg/ml [30.7, 344.4]; p = .001), IL-8 (32.0 pg/ml [5.6, 53.1] vs 59.1 pg/ml [39.2, 119.4]; p = .003), IL-15 (12.0 pg/ml [12.0, 12.0] vs 12.0 pg/ml [12.0, 126.7]; p = .03), and IFN-α (5.1 pg/mL [5.1, 5.1] vs 5.1 pg/ml [5.1, 26.3]; p = .04). Regulated upon Activation, Normal T Cell Expressed and Secreted (RANTES) was higher in transplant SAB vs nontransplant SAB (mean [SD]: 750.2 pg/ml [194.6] vs 656.5 pg/ml [147.6]; p = .046).

Effect of Different Rituximab Doses on B Cell Count, Anti-A/B Antibody Titer, Graft Function, and Infectious Complications in ABO-Incompatible Renal Transplantation: A Prospective Study

BACKGROUND

ABO-incompatible kidney transplantation (ABOiKT) has been accepted as a viable and cost-effective modality with outcomes comparable to ABO-compatible transplants, but there is a concern regarding higher infectious complications in ABOiKT because of the heightened immunosuppression. The desensitization protocol normally includes antibody removal, B cell depletion by rituximab (RTX), and immunomodulation with intravenous immunoglobulin. Efforts have been made over the years to decrease the dose of RTX in an effort to decrease the infective complications. There is limited literature about the minimum effective dose of RTX, which can cause an effective B cell depletion. This prospective study was designed to correlate the RTX dose with peripheral absolute B cell count, graft function, graft and patient survival, and infective complications.

METHODS

This study included 52 adult ABOiKT recipients with anti-A/B antibody titer up to a maximum of 1:512. The participants were divided into 2 groups of 26 each according to the RTX dosage used: Group A received 100 mg/patient, and Group B received 200 mg/patient. RTX was given 14 days prior to transplant after B cell measurement by flow cytometry. The outcomes were compared after 1 year of follow-up.

RESULTS

Both the dosages effectively depleted the absolute B cell count. Although patient survivals, graft survival, graft function, acute rejection episodes, and post-transplant hospital stay were similar in both groups, infective complications were significantly higher in group B.

CONCLUSION

A low dose (100 mg/patient) of RTX produces effective depletion of B cells while lowering the infective complications in ABOiKT.

Post kidney transplant histoplasmosis: An under-recognized diagnosis in India

Histoplasmosis is an invasive mycosis caused by fungus Histoplasma capsulatum. Clinical features of histoplasmosis are often nonspecific, but patients with disseminated infection may present with severe manifestations posing an increasing threat to patients with various immunocompromised conditions. It is often misdiagnosed as tuberculosis in endemic regions leading to high mortality. There is under-reporting of histoplasmosis in solid organ transplant from India undermining its actual incidence and impact. As a result of the potentially fatal nature of the disease, careful evaluation with tissue diagnosis is recommended. We present a series of five cases of disseminated histoplasmosis in renal transplant recipients from our centre, highlighting its significance as differential diagnosis in this population. To our knowledge, this is the largest case series reported from India in renal transplant patients.

The Inhibition of P-Selectin Reduced Severe Acute Lung Injury in Immunocompromised Mice

In an immunocompetent host, excess infiltration of immune cells in the lung is a key factor in infection-induced severe acute lung injury. Kidney transplant patients are immunocompromised by the use of immunosuppressive drugs. Immune cell infiltration in the lung in a renal transplant recipient suffering from pulmonary infection is significantly less than that in an immunocompetent host; however, the extent of lung injury in renal transplant patients is more serious than that in immunocompetent hosts. Therefore, we explored the role of platelet activation in a Klebsiella pneumoniae-induced lung injury model with P-selectin gene knockout mice or wild-type mice. Our study suggested that the inhibition of platelets reduced severe acute lung injury and increased survival after acute lung infection in mice. In addition, P-selectin expression on the surface of platelets in mice increased after administration of immunosuppressive drugs, and the extent of lung injury induced by infection decreased in P-selectin gene knockout mice. In conclusion, p-selectin plays a key role in severe acute lung injury in immunocompromised mice by reducing platelet activation and inflammatory processes.

Outcomes of kidney transplant recipients admitted to the intensive care unit: a retrospective study of 200 patients

Background

Risk of over-immunosuppression or immunization may mitigate the overall and long-term renal outcomes of kidney transplant recipients (KTR) admitted to the ICU in the modern era but remain poorly described. Thus, there is an unmet need to better characterize the survival of KTR admitted to the ICU, but also the renal and immunological outcomes of survivors.

Methods

Retrospective observational study that included 200 KTR admitted between 2010 and 2016 to the ICU of a teaching hospital (median age 61 years [IQR 50.7–68]; time from transplantation 41 months [IQR 5–119]). Survival curves were compared using the Log-rank test.

Results

Mortality rates following admission to the ICU was low (26.5% at month-6), mainly related to early mortality (20% in-hospital), and predicted by the severity of the acute condition (SAPS2 score) but also by Epstein Barr Virus proliferation in the weeks preceding the admission to the ICU. Acute kidney injury (AKI) was highly prevalent (85.1%). Progression toward chronic kidney disease (CKD) was observed in 45.1% of survivors. 15.1% of survivors developed new anti-HLA antibodies (donor-specific antibodies 9.2% of cases) that may impact the long-term renal transplantation function.

Conclusions

Notwithstanding the potential biases related to the retrospective and monocentric nature of this study, our findings obtained in a large cohort of KTR suggest that survival of KTR admitted in ICU is good but in-ICU management of these patients may alter both survival and AKI to CKD transition, as well as HLA immunization. Further interventional studies, including systematic characterization of the Epstein Barr virus proliferation at the admission (i.e., a potential surrogate marker of an underlying immune paralysis and frailty) will need to address the optimal management of immunosuppressive regimen in ICU to improve survival but also renal and immunological outcomes.

Diagnostic and therapeutic approach to infectious diseases in solid organ transplant recipients

Purpose

Prognosis of solid organ transplant (SOT) recipients has improved, mainly because of better prevention of rejection by immunosuppressive therapies. However, SOT recipients are highly susceptible to conventional and opportunistic infections, which represent a major cause of morbidity, graft dysfunction and mortality.

Methods

Narrative review.

Results

We cover the current epidemiology and main aspects of infections in SOT recipients including risk factors such as postoperative risks and specific risks for different transplant recipients, key points on anti-infective prophylaxis as well as diagnostic and therapeutic approaches. We provide an up-to-date guide for management of the main syndromes that can be encountered in SOT recipients including acute respiratory failure, sepsis or septic shock, and central nervous system infections as well as bacterial infections with multidrug-resistant strains, invasive fungal diseases, viral infections and less common pathogens that may impact this patient population.

Conclusion

We provide state-of the art review of available knowledge of critically ill SOT patients with infections.

Prise en charge du transplanté rénal en réanimation

La transplantation rénale est la thérapeutique de choix de l’insuffisance rénale chronique au stade ultime, son usage est de plus en plus large. Les progrès réalisés dans les traitements immunosuppresseurs ont permis une amélioration de la durée de vie du greffon, mais au prix d’une augmentation des complications cardiovasculaires et infectieuses. Environ 5 % des transplantés rénaux présentent des complications sévères qui nécessitent une prise en charge intensive. Elles sont principalement de cause infectieuse et dominées par la défaillance respiratoire aiguë. L’insuffisance rénale aiguë est commune, elle affecte la fonction du greffon à court et long termes. La prise en charge en réanimation de ces complications doit prendre en compte le terrain particulier du transplanté rénal et les effets délétères de l’immunosuppression, condition nécessaire à une amélioration de la mortalité qui reste à plus de 30 %.

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.

Cytomegalovirus infection and graft rejection as risk factors for pneumocystis pneumonia in solid organ transplant recipients: A systematic review and meta-analysis

A growing number of publications have reported the outbreaks of post-transplant pneumocystis pneumonia (PJP). In most studies, the onset of PJP was beyond 6-12 months of prophylaxis. Cytomegalovirus (CMV) infection and allograft rejection have been repeatedly reported as probable risk factors for post-transplant PJP. In this systematic review and meta-analysis, we determined the pooled effect estimates of these 2 variables as risk factors. Data sources included PUBMED, MEDLINE-OVID, EMBASE-OVID, Cochrane Library, Networked Digital Library of Theses and Dissertations, World Health Organization, and Web of Science. We excluded publications related to hematopoietic stem cell transplantation (HSCT) or Human Immunodeficiency Virus (HIV) patients. Eventually, 15 studies remained for the final stage of screening. Cytomegalovirus infection (OR: 3.30, CI 95%: 2.07-5.26, I² : 57%, P = 0.006) and allograft rejection (OR:2.36, CI95%: 1.54-3.62, I2: 45.5%, P = 0.05) significantly increased the risk of post-transplant PJP. Extended prophylaxis targeting recipients with allograft rejection or CMV infection may reduce the risk of PJP.

Patients immunodéprimés, quel pathogène pour quel déficit immunitaire ? (en dehors de l’infection à VIH)

Le nombre de patients immunodéprimés ne cesse d’augmenter en raison de l’amélioration du pronostic global du cancer et de l’utilisation croissante d’immunosuppresseurs tant en transplantation qu’au cours des maladies auto-immunes. Les infections sévères restent la première cause d’admission en réanimation dans cette population et sont dominées par les atteintes respiratoires. On distingue les déficits primitifs, volontiers révélés dans l’enfance, des déficits secondaires (médicamenteux ou non), les plus fréquents. Dans tous les cas, les sujets sont exposés à des infections inhabituelles de par leur fréquence, leur type et leur sévérité. À côté des pyogènes habituels, les infections opportunistes et la réactivation d’infections latentes font toute la complexité de la démarche diagnostique. Celle-ci doit être rigoureuse, orientée par le type de déficit, les antécédents, les prophylaxies éventuelles et la présentation clinicoradiologique. Elle permettra seule de guider le traitement probabiliste et les examens étiologiques, l’absence de diagnostic étant associée à une mortalité élevée.

Clinical Features of Kidney Transplant Recipients Admitted to the Intensive Care Unit

INTRODUCTION

There is a paucity of data regarding the complications in kidney transplant patients who may require intensive care unit (ICU) management, despite being the most common solid organ transplant worldwide.

OBJECTIVE

To identify the main reasons for ICU admission and to determine the factors associated with hospital mortality in kidney transplant recipients.

DESIGN

This single-center retrospective cohort study was conducted between September 2013 and June 2014, including all consecutive kidney transplant patients requiring ICU admission. We collected data on patient demographics, transplant characteristics, clinical data, and prognostic scores. The independent determinants of hospital mortality were identified by multiple logistic regression analysis. We also assessed the performance of Simplified Acute Physiology Score 3 (SAPS 3) and Acute Physiology and Chronic Health Evaluation II (APACHE II) scores.

RESULTS

We analyzed data from 413 patients, the majority of whom were admitted late after renal transplantation (1169 days; 63-3003 days). The main reason for admission was sepsis (33.2%), followed by cardiovascular disease (16%). Age (odds ratio [OR] 1.05, confidence interval [CI], 1.01-1.09), SAPS 3 score (OR 1.04, CI, 1.01-1.08), the need for mechanical ventilation (OR 26.47, CI, 10.30-68.08), and vasopressor use (OR 3.34, CI, 1.37-8.13) were independently associated with hospital mortality. The performance of SAPS 3 and APACHE II scores was poor in this population and overestimated the mortality rates.

CONCLUSION

Sepsis was the main reason for ICU admission in kidney transplant recipients, followed by cardiovascular disease. Age and disease severity were associated with hospital mortality.

The diagnostic yield and complications of open lung biopsies in kidney transplant patients with pulmonary disease

BACKGROUND

The purpose of this study was to assess the efficacy of open lung biopsy (OLB) in determining the specific diagnosis and the related complications in patients with undiagnosed diffuse pulmonary infiltrates.

METHODS

This single center, retrospective study included adult kidney transplant patients who underwent OLB. The patients had diffuse pulmonary infiltrates without definitive diagnoses and failed to respond to empiric antibiotic treatment. We analyzed the number of specific diagnoses, changes in treatment and the occurrence of complications in these patients. A logistic regression was used to determine which variables were predictors of hospital mortality.

RESULTS

From April 2010 to April 2014, 87 patients consecutively underwent OLB. A specific diagnosis was reached in 74 (85.1%) patients. In 46 patients (53%), their therapeutic management was changed after the OLB results. Twenty-five (28.7%) patients had complications related to the OLB. The hospital mortality rate was 25.2%. Age, SAPS3 score and complications related to the procedure were independent predictors of all-cause mortality.

CONCLUSIONS

OLB is a high-risk procedure with a high diagnostic yield in kidney transplant patients with diffuse pulmonary infiltrates who did not have a definitive diagnosis and who failed to respond to empiric antibiotic treatment. Complications related to OLB were common and were independently associated with intra-hospital mortality.

Outcomes and Mortality in Renal Transplant Recipients Admitted to the Intensive Care Unit

INTRODUCTION

In the intensive care unit (ICU), mortality is considered higher among renal transplant recipients than among nontransplantation patients. However, data regarding severe complications after kidney transplantation are scarce.

MATERIALS AND METHODS

In this study, we evaluated all consecutive renal transplant recipients admitted to our ICU between July 2012 and July 2013 (n = 70), comparing their outcomes with those of a control group of nontransplantation patients admitted during the same period (n = 153). Among the transplant recipients, we compared survivors and nonsurvivors to identify predictors of ICU mortality.

RESULTS

The mean age of the transplant recipients was 52 ± 13 years. Of the 70 transplant recipients, 18 (25%) required mechanical ventilation, 28 (40%) required inotropic support, and 27 (39%) required hemodialysis, all of which are factors that worsen the prognosis significantly. Twenty-two (31%) of the transplant recipients died in the ICU and 17 (24%) died within 30 days after ICU discharge, rates similar to those observed for the control group.

CONCLUSIONS

We observed similar mortality between recipient and control groups, albeit the mortality was higher in the clinical group. In the multivariate model, the need for mechanical ventilation and the need for hemodialysis were independently associated with mortality.

Bacteria Isolated From Respiratory Tract Specimens of Renal Recipients With Acute Respiratory Distress Syndrome Due to Pneumonia: Epidemiology and Susceptibility of the Strains

OBJECTIVE

We estimated species distribution and frequency of antimicrobial resistance among bacterial pathogens isolated from respiratory tract specimens of renal recipients with acute respiratory distress syndrome (ARDS) due to pneumonia.

METHODS

We retrospectively collected patient demographics and clinical characteristics and microbiologic culture data with the use of standard microbiologic procedures and commercially available tests.

RESULTS

From January 2001 to August 2014, 320 respiratory tract specimens were obtained from 94 renal recipients with ARDS. Bacterial cultures were positive in 134 specimens from 68 recipients (72.3%), yielding 139 bacterial strains. The most commonly isolated species were gram-negative bacteria (111 isolates) with dominance of Acinetobacter baumanii (29.7%) and Pseudomonas aeruginosa (18.0%). The gram-negative bacteria were relatively resistant to 1st- and 2nd-generation cephalosporin and monocyclic beta-lactam and relatively sensitive to levofloxacin and meropenem, with rates of resistance of 80.2%, 76.6%, 73.9%, 36.0%, and 44.1%, respectively. The gram-positive bacteria, excluding Streptococcus uberis, were sensitive to glycopeptides and oxazolidone.

CONCLUSIONS

Gram-negative bacteria predominated as 79.9% of isolates from respiratory tract specimens of renal recipients with ARDS. The gram-negative bacteria were relatively sensitive to levofloxacin and meropenem and the gram-positive bacteria were sensitive to glycopeptides and oxazolidone.

Mortality predictors in recipients developing acute respiratory distress syndrome due to pneumonia after kidney transplantation

BACKGROUND

The aim of the present study was to investigate the risk factors related to hospital mortality due to infection in kidney recipients with ARDS meeting the Berlin definition.

METHODS

Univariate and multivariate logistic regression analysis were used to confirm the independent risk factors related to infection-associated mortality.

RESULTS

From January 2001 to August 2014, a total of 94 recipients with acute respiratory dress syndrome (ARDS) caused by pneumonia following kidney transplantation were enrolled in the present study. The most common type of infection was bacterial (52/94; 55.3%), viral (25/94; 26.6%), and polymicrobial (14/94; 14.9%). The most common ARDS was diagnosed within 6 months after transplantation (76/94; 80.9%). There were 39 deaths in these recipients (39/94; 41.5%). Eleven (11.7%) patients had mild, 47 (50.0%) moderate, and 36 (38.3%) severe ARDS; mortality was 27.3, 27.7, and 63.9%, respectively. The independent predictors of infection-related mortality were serum creatinine level >1.5 mg/dL at ARDS onset (OR 3.5 (95%CI 1.2-10.1), p = 0.018) and severe ARDS (OR 3.6 (95%CI 1.4-9.7), p = 0.009) in the multivariate analysis.

CONCLUSION

Infection-related mortality in kidney transplant patients with ARDS was associated with high serum creatinine level and severe ARDS.

The Critically Ill Kidney Transplant Recipient: A Narrative Review

Kidney transplantation is the most common solid organ transplantation performed worldwide. Up to 6% of kidney transplant recipients experience a life-threatening complication that requires ICU admission, chiefly in the late posttransplantation period (≥ 6 months). Acute respiratory failure and septic shock are the main reasons for ICU admission. Cardiac pulmonary edema, bacterial pneumonia, acute graft pyelonephritis, and bloodstream infections account for the vast majority of diagnoses in the ICU. Pneumocystis jirovecii pneumonia is the most common opportunistic infection, and one-half of the patients so infected require mechanical ventilation. The incidence of cytomegalovirus visceral infections in the era of preemptive therapy has dramatically decreased. Drug-related neutropenia, sirolimus-related pneumonitis, and posterior reversible encephalopathy syndrome are among the most common immunosuppression-associated toxic effects. Importantly, the impact of critical illness on graft function is worrisome. Throughout the ICU stay, acute kidney injury is common, and about 40% of the recipients require renal replacement therapy. One-half of the patients are discharged alive and free from dialysis. Hospital mortality can reach 30% and correlates with acute illness severity and reason for ICU admission. Transplant characteristics are not predictors of short-term survival. Graft survival depends on pre-ICU graft function, disease severity, and renal toxicity of ICU investigations and treatments.

Death and kidney allograft dysfunction after bacteremia

BACKGROUND

Some studies have reported causal associations between bacteremia and mortality or allograft loss in kidney transplant recipients (KTR). However, few studies have assessed the clinical course of kidney function and the risk of acute allograft rejection after bacteremia.

METHODS

We retrospectively reviewed 902 kidney transplants performed at Nagoya Daini Red Cross Hospital between January 1, 2002 and March 31, 2014. Forty-five living donor kidney transplant recipients with single bacteremia were included. We analyzed death, change in kidney function, and development of acute allograft rejection 12 months after bacteremia according to the following groups: primary source of bacteremia (urinary tract or other sources), site of acquisition (community acquired or nosocomial), severity (not meeting the systemic inflammatory response syndrome criteria and sepsis or severe sepsis and septic shock), empiric antibiotic use (appropriate or inappropriate), and baseline kidney function (estimated glomerular filtration rate ≤44.7 or ≥44.8 ml/min).

RESULTS

Urinary tract infection (UTI) was the leading cause of bacteremia (68.9 %), and Escherichia coli was the most common pathogen. Three cases (6.7 %) died of infection that caused bacteremia within 12 months. Pneumonia accounted for two-thirds. Kidney function declined 1 week after bacteremia (P < 0.05), particularly in severe cases. Thereafter, kidney function was comparable to baseline level in each group (P ≥ 0.05). Severe UTI was associated with subsequent acute allograft rejection (P = 0.03).

CONCLUSIONS

Pneumonia in KTR should be managed with caution. Kidney function generally returned to baseline level after bacteremia. However, severe UTI may be associated with subsequent acute allograft rejection.

The Risk of Septicemia in End-Stage Renal Disease With and Without Renal Transplantation: A Propensity-Matched Cohort Study

End-stage renal disease (ESRD) is a well-known risk factor for septicemia. Renal transplantation (RTx) is the treatment of choice for ESRD. However, RTx recipients should undergo long-term immunosuppressive therapy. The aim of this study was to evaluate the risk of septicemia in ESRD patients with and without RTx.This cohort study used the National Health Insurance (NHI) data of Taiwan from 2000 to 2010. The RTx group consisted of 3286 RTx recipients. The non-RTx comparison group also consisted of 3286 subjects with ESRD matched by propensity scores for age, sex, index date, comorbidities, and medications. The subjects were followed until the end of 2011 to evaluate the septicemia risk.The risk of septicemia was lower in the RTx group than the non-RTx group, with an adjusted hazard ratio of 0.73 [95% confidence interval (CI) = 0.64-0.84, P < 0.001]. In addition, we observed insignificantly lower intensive care unit (ICU) admission rate (35.8% vs. 39.8%) and lower 30-day all-cause mortality rate (17.2% vs. 18.5%) in the RTx group than the non-RTx group. However, the mean cost for septicemia in the RTx group was insignificantly higher than the non-RTx group (7175 vs. 6421 USD, P = 0.39).RTx recipients had a significantly reduced risk of developing septicemia compared to the propensity-matched non-RTx ESRD patients. The ICU admission and 30-day all-cause mortality rates also slightly decreased in RTx recipients but without statistical significance.