Improved survival among ICU-hospitalized patients with community-acquired pneumonia by unidentified organisms: a multicenter case-control study.

A retrospective analysis from prospectively collected data was conducted in intensive care units (ICUs) at 33 hospitals in Europe comparing the trend in ICU survival among adults with severe community-acquired pneumonia (CAP) due to unknown organisms from 2000 to 2015. The secondary objective was to establish whether changes in antibiotic policies were associated with different outcomes. ICU mortality decreased (p = 0.02) from 26.9 % in the first study period (2000-2002) to 15.7 % in the second period (2008-2015). Demographic data and clinical severity at admission were comparable between groups, except for age over 65 years and incidence of cardiomyopathy. Over time, patients received higher rates of combination therapy (94.3 vs. 77.2 %; p < 0.01) and early (<3 h) antibiotic delivery (72.9 vs. 50.3 %; p < 0.01); likewise, the 2008-2015 group was more likely to receive adequate antibiotic prescription [as defined by the Infectious Diseases Society of America/American Thoracic Society (IDSA/ATS) guidelines] than the 2000-2002 group (70.7 vs. 48.2 %; p < 0.01). Multivariate analysis showed an independent association between decreased ICU mortality and early (<3 h) antibiotic administration [odds ratio (OR) 3.48 [1.70-7.15], p < 0.01] or adequate antibiotic prescription according to guidelines (OR 2.22 [1.11-4.43], p = 0.02). In conclusion, our findings suggest that ICU mortality in severe CAP due to unidentified organisms has decreased in the last 15 years. Several changes in management and better compliance with guidelines over time were associated with increased survival.

Genetic engineering strategies to prevent the effects of antibody and complement on xenogeneic chondrocytes.

Advances in animal transgenesis may allow using xenogeneic chondrocytes in tissue-engineering applications for clinical cartilage repair. Porcine cartilage is rejected by humoral and cellular mechanisms that could be overcome by identifying key molecules triggering rejection and developing effective genetic-engineering strategies. Accordingly, high expression of α1,2-fucosyltransferase (HT) in xenogeneic cartilage protects from galactose α1,3-galactose (Gal)-mediated antibody responses. Now, we studied whether expression of a complement inhibitor provides further protection. First, porcine articular chondrocytes (PAC) were isolated from non-transgenic, single and double transgenic pigs expressing HT and moderate levels of human CD59 (hCD59) and their response to human serum was assessed. High recombinant expression of human complement regulatory molecules hCD59 and hDAF was also attained by retroviral transduction of PAC for further analyses. Complement activation on PAC after exposure to 20 % human serum for 24 hours mainly triggered the release of pro-inflammatory cytokines IL-6 and IL-8. Transgenic expression of HT and hCD59 did not suffice to fully counteract this effect. Nevertheless, the combination of blocking anti-Gal antibodies (or C5a) and high hCD59 levels conferred very high protection. On the contrary, high hDAF expression attained the most dramatic reduction in IL-6/IL-8 secretion by a single strategy, but the additional inhibition of anti-Gal antibodies or C5a did not provide further improvement. Notably, we demonstrate that both hCD59 and hDAF inhibit anaphylatoxin release in this setting. In conclusion, our study identifies genetic-engineering approaches to prevent humoral rejection of xenogeneic chondrocytes for use in cartilage repair.

Exploiting natural anti-carbohydrate antibodies for therapeutic purposes.

Natural anti-carbohydrate antibodies (NAbC) are antibodies that target glycans and are continuously produced without apparent external antigen stimulation. Clinically, NAbC are recognized by the adverse reactions to ABO mismatched blood transfusions or organ transplantation and the rejection of xenografts. These clinical effects do not reflect the biological functions of NAbC. However, they launch the possibility of using NAbC for boosting immunity in different clinical settings by means of: 1) expression of glycan antigens in elements that do not hold them to allow the binding and reactivity of existing NAbC; 2) removal of existing NAbC; 3) manipulation of the glycosylation pattern of NAbC.

Inhibition of complement component C5 protects porcine chondrocytes from xenogeneic rejection.

OBJECTIVE: Tissue-based xenografts such as cartilage are rejected within weeks by humoral and cellular mechanisms that preclude its clinical application in regenerative medicine. The problem could be overcome by identifying key molecules triggering rejection and the development of genetic-engineering strategies to counteract them. Accordingly, high expression of α1,2-fucosyltransferase (HT) in xenogeneic cartilage reduces the galactose α1,3-galactose (Gal) antigen and delays rejection. Yet, the role of complement activation in this setting is unknown. DESIGN: To determine its contribution, we assessed the effect of inhibiting C5 complement component in α1,3-galactosyltransferase-knockout (Gal KO) mice transplanted with porcine cartilage and studied the effect of human complement on porcine articular chondrocytes (PAC). RESULTS: Treatment with an anti-mouse C5 blocking antibody for 5 weeks enhanced graft survival by reducing cellular rejection. Moreover, PAC were highly resistant to complement-mediated lysis and primarily responded to human complement by releasing IL-6 and IL-8. This occurred even in the absence of anti-Gal antibody and was mediated by both C5a and C5b-9. Indeed, C5a directly triggered IL-6 and IL-8 secretion and up-regulated expression of swine leukocyte antigen I (SLA-I) and adhesion molecules on chondrocytes, all processes that enhance cellular rejection. Finally, the use of anti-human C5/C5a antibodies and/or recombinant expression of human complement regulatory molecule CD59 (hCD59) conferred protection in correspondence with their specific functions. CONCLUSIONS: Our study demonstrates that complement activation contributes to rejection of xenogeneic cartilage and provides valuable information for selecting approaches for complement inhibition.

Quorum sensing communication between lipid-based artificial cells.

Population behavior based on quorum sensing communication is a key property of living microorganisms. Here, we show quorum sensing behavior in an artificial cell population consisting of giant lipid vesicles loaded with sender-receiver machinery (enzymes and responsive biomolecules). Our system allows the examination of the collective output based on cell density, fuel concentration and proximity, which are important factors controlling natural quorum sensing behavior.

Determinants of prescription and choice of empirical therapy for hospital-acquired and ventilator-associated pneumonia.

The objectives of this study were to assess the determinants of empirical antibiotic choice, prescription patterns and outcomes in patients with hospital-acquired pneumonia (HAP)/ventilator-associated pneumonia (VAP) in Europe. We performed a prospective, observational cohort study in 27 intensive care units (ICUs) from nine European countries. 100 consecutive patients on mechanical ventilation for HAP, on mechanical ventilation>48 h or with VAP were enrolled per ICU. Admission category, sickness severity and Acinetobacter spp. prevalence>10% in pneumonia episodes determined antibiotic empirical choice. Trauma patients were more often prescribed non-anti-Pseudomonas cephalosporins (OR 2.68, 95% CI 1.50-4.78). Surgical patients received less aminoglycosides (OR 0.26, 95% CI 0.14-0.49). A significant correlation (p<0.01) was found between Simplified Acute Physiology Score II score and carbapenem prescription. Basal Acinetobacter spp. prevalence>10% dramatically increased the prescription of carbapenems (OR 3.5, 95% CI 2.0-6.1) and colistin (OR 115.7, 95% CI 6.9-1,930.9). Appropriate empirical antibiotics decreased ICU length of stay by 6 days (26.3±19.8 days versus 32.8±29.4 days; p=0.04). The antibiotics that were prescribed most were carbapenems, piperacillin/tazobactam and quinolones. Median (interquartile range) duration of antibiotic therapy was 9 (6-12) days. Anti-methicillin-resistant Staphylococcus aureus agents were prescribed in 38.4% of VAP episodes. Admission category, sickness severity and basal Acinetobacter prevalence>10% in pneumonia episodes were the major determinants of antibiotic choice at the bedside. Across Europe, carbapenems were the antibiotic most prescribed for HAP/VAP.

A Phase I/II Clinical Trial to evaluate the efficacy of baricitinib to prevent respiratory insufficiency progression in onco-hematological patients affected with COVID19: A structured summary of a study protocol for a randomised controlled trial.

OBJECTIVES: Baricitinib is supposed to have a double effect on SARS-CoV2 infection. Firstly, it reduces the inflammatory response through the inhibition of the Januse-Kinase signalling transducer and activator of transcription (JAK-STAT) pathway. Moreover, it reduces the receptor mediated viral endocytosis by AP2-associated protein kinase 1 (AAK1) inhibition. We propose the use of baricinitib to prevent the progression of the respiratory insufficiency in SARS-CoV2 pneumonia in onco-haematological patients. In this phase Ib/II study, the primary objective in the safety cohort is to describe the incidence of severe adverse events associated with baricitinib administration. The primary objective of the randomized phase (baricitinib cohort versus standard of care cohort) is to evaluate the number of patients who did not require mechanical oxygen support since start of therapy until day +14 or discharge (whichever it comes first). The secondary objectives of the study (only randomized phase of the study) are represented by the comparison between the two arms of the study in terms of mortality and toxicity at day+30. Moreover, a description of the immunological related changes between the two arms of the study will be reported. TRIAL DESIGN: The trial is a phase I/II study with a safety run-in cohort (phase 1) followed by an open label phase II randomized controlled trial with an experimental arm compared to a standard of care arm. PARTICIPANTS: The study will be performed at the Institut Català d'Oncologia, a tertiary level oncological referral center in the Catalonia region (Spain). The eligibility criteria are: patients > 18 years affected by oncological diseases; ECOG performance status < 2 (Karnofsky score > 60%); a laboratory confirmed infection with SARS-CoV-2 by means of real -time PCR; radiological signs of low respiratory tract disease; absence of organ dysfunction (a total bilirubin within normal institutional limits, AST/ALT≤2.5 X institutional upper limit of normal, alkaline phosphatase ≤2.5 X institutional upper limit of normal, coagulation within normal institutional limits, creatinine clearance >30 mL/min/1.73 m2 for patients with creatinine levels above institutional normal); absence of HIV infection; no active or latent HBV or HCV infection. The exclusion criteria are: patients with oncological diseases who are not candidates to receive any active oncological treatment; hemodynamic instability at time of study enrollment; impossibility to receive oral medication; medical history of recent or active pulmonary embolism or deep venous thrombosis or patients at high-risk of suffering them (surgical intervention, immobilization); multi organ failure, rapid worsening of respiratory function with requirement of fraction of inspired oxygen (FiO2) > 50% or high-flow nasal cannula before initiation of study treatment; uncontrolled intercurrent illness (ongoing or severe active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements); allergy to one or more of study treatments; pregnant or breastfeeding women; positive pregnancy test in a pre-dose examination. Patients should have the ability to understand, and the willingness to sign, a written informed consent document; the willingness to accept randomization to any assigned treatment arm; and must agree not to enroll in another study of an investigational agent prior to completion of Day +28 of study. An electronic Case Report Form in the Research Electronic Data Capture (REDCap) platform will be used to collect the data of the trial. Removal from the study will apply in case of unacceptable adverse event(s), development of an intercurrent illness, condition or procedural complication, which could interfere with the patient's continued participation and voluntary patient withdrawal from study treatment (all patients are free to withdraw from participation in this study at any time, for any reasons, specified or unspecified, and without prejudice). INTERVENTION AND COMPARATOR: Treatment will be administered on an inpatient basis. We will compare the experimental treatment with baricitinib plus the institutional standard of care compared with the standard of care alone. During the phase I, we will define the dose-limiting toxicity of baricitinib and the dose to be used in the phase 2 part of the study. The starting baricitinib dose will be an oral tablet 4 mg-once daily which can be reduced to 2 mg depending on the observed toxicity. The minimum duration of therapy will be 5 days and it can be extended to 7 days. The standard of care will include the following therapies. Antibiotics will be individualized based on clinical suspicion, including the management of febrile neutropenia. Prophylaxis of thromboembolic disease will be administered to all participants. Remdesivir administration will be considered only in patients with severe pneumonia (SatO2 <94%) with less than 7 days of onset of symptoms and with supplemental oxygen requirements but not using high-flow nasal cannula, non-invasive or invasive mechanical ventilation or extracorporeal membrane oxygenation (ECMO). In the randomized phase, tocilizumab or interferon will not be allowed in the experimental arm. Tocilizumab can be used in patients in the standard of care arm at the discretion of the investigator. If it is prescribed it will be used according to the following criteria: patients who, according to his baseline clinical condition, would be an ICU tributary, interstitial pneumonia with severe respiratory failure, patients who are not on mechanical ventilation or ECMO and who are still progressing with corticoid treatment or if they are not candidates for corticosteroids. Mild ARDS (PAFI <300 mmHg) with radiological or blood gases deterioration that meets at least one of the following criteria: CRP >100mg/L D-Dimer >1,000µg/L LDH >400U/L Ferritin >700ng/ml Interleukin 6 ≥40ng/L. The use of tocilizumab is not recommended if there are AST/ALT values greater than 10 times the upper limit of normal, neutrophils <500 cells/mm3, sepsis due to other pathogens other than SARS-CoV-2, presence of comorbidity that can lead to a poor prognosis, complicated diverticulitis or intestinal perforation, ongoing skin infection. The dose will be that recommended by the Spanish Medicine Agency in patients ≥75Kg: 600mg dose whereas in patients <75kg: 400mg dose. Exceptionally, a second infusion can be assessed 12 hours after the first in those patients who experience a worsening of laboratory parameters after a first favourable response. The use of corticosteroids will be recommended in patients who have had symptoms for more than 7 days and who meet all the following criteria: need for oxygen support, non-invasive or invasive mechanical ventilation, acute respiratory failure or rapid deterioration of gas exchange, appearance or worsening of bilateral alveolar-interstitial infiltrates at the radiological level. In case of indication, it is recommended: dexamethasone 6mg/d p.o. or iv for 10 days or methylprednisolone 32mg/d orally or 30mg iv for 10 days or prednisone 40mg day p.o. for 10 days. MAIN OUTCOMES: Phase 1 part: to describe the toxicity profile of baricitinib in COVID19 oncological patients during the 5-7 day treatment period and until day +14 or discharge (whichever it comes first). Phase 2 part: to describe the number of patients in the experimental arm that will not require mechanical oxygen support compared to the standard of care arm until day +14 or discharge (whichever it comes first). RANDOMISATION: For the phase 2 of the study, the allocation ratio will be 1:1. Randomization process will be carried out electronically through the REDcap platform ( https://www.project-redcap.org/ ) BLINDING (MASKING): This is an open label study. No blinding will be performed. NUMBERS TO BE RANDOMISED (SAMPLE SIZE): The first part of the study (safety run-in cohort) will consist in the enrollment of 6 to 12 patients. In this population, we will test the toxicity of the experimental treatment. An incidence of severe adverse events grade 3-4 (graded by Common Terminology Criteria for Adverse Events v.5.0) inferior than 33% will be considered sufficient to follow with the next part of the study. The second part of the study we will perform an interim analysis of efficacy at first 64 assessed patients and a definitive one will analyze 128 assessed patients. Interim and definitive tests will be performed considering in both cases an alpha error of 0.05. We consider for the control arm this rate is expected to be 0.60 and for the experimental arm of 0.80. Considering this data, a superiority test to prove a difference of 0.20 with an overall alpha error of 0.10 and a beta error of 0.2 will be performed. Considering a 5% of dropout rate, it is expected that a total of 136 patients, 68 for each study arm, will be required to complete study accrual. TRIAL STATUS: Version 5.0. 14th October 2020 Recruitment started on the 16th of December 2020. Expected end of recruitment is June 2021. TRIAL REGISTRATION: AEMPs: 20-0356 EudraCT: 2020-001789-12, https://www.clinicaltrialsregister.eu/ctr-search/search (Not publically available as Phase I trial) Clinical trials: BARCOVID19, https://www.clinicaltrials.gov/ (In progress) FULL PROTOCOL: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol."

Control of endemic multidrug-resistant Gram-negative bacteria after removal of sinks and implementing a new water-safe policy in an intensive care unit.

BACKGROUND: Contaminated handwashing sinks have been identified as reservoirs that can facilitate colonization/infection of patients with multidrug-resistant (MDR) Gram-negative bacteria (GNB) in intensive care units (ICUs). AIM: To assess the impact of removing patients' sinks and implementing other water-safe strategies on the annual rates of ICU-acquired MDR-GNB. METHODS: This six-year quasi-experimental study was conducted from January 2011 to December 2016. The intervention was carried out in August 2014 in two adult ICU wards with 12 rooms each. To assess the changes in annual MDR-GNB rates before and after the intervention, we used segmented regression analysis of an interrupted time-series. Crude relative risk (RR) rates were also calculated. FINDINGS: The incidence rates of MDR-GNB were 9.15 and 2.20 per 1000 patient-days in the pre- and post-intervention periods, respectively. This yielded a crude RR of acquiring MDR-GNB of 0.24 (95% confidence interval: 0.17-0.34). A significant change in level was observed between the MDR-GNB rate at the first point of the post-intervention period and the rate predicted by the pre-intervention time trend. CONCLUSION: The implementation of a new water-safe policy, which included the removal of sinks from all patient rooms, successfully improved the control of MDR-GNB spread in an ICU with endemic infection. Our results support the contribution of sink use with the incidence of MDR-GNB in endemic environments.

Drug Delivery Nanosystems for the Localized Treatment of Glioblastoma Multiforme.

Glioblastoma multiforme is one of the most prevalent and malignant forms of central nervous system tumors. The treatment of glioblastoma remains a great challenge due to its location in the intracranial space and the presence of the blood⁻brain tumor barrier. There is an urgent need to develop novel therapy approaches for this tumor, to improve the clinical outcomes, and to reduce the rate of recurrence and adverse effects associated with present options. The formulation of therapeutic agents in nanostructures is one of the most promising approaches to treat glioblastoma due to the increased availability at the target site, and the possibility to co-deliver a range of drugs and diagnostic agents. Moreover, the local administration of nanostructures presents significant additional advantages, since it overcomes blood⁻brain barrier penetration issues to reach higher concentrations of therapeutic agents in the tumor area with minimal side effects. In this paper, we aim to review the attempts to develop nanostructures as local drug delivery systems able to deliver multiple agents for both therapeutic and diagnostic functions for the management of glioblastoma.

Bloodstream infection related to catheter connections: a prospective trial of two connection systems.

Bloodstream infections (BSIs) related to central venous catheters (CVCs) and arterial catheters (ACs) are an increasing problem in the management of critically ill patients. Our objective was to assess the efficacy of a needle-free valve connection system (SmartSite), Alaris Medical Systems, San Diego, CA, USA) in the prevention of catheter-related bloodstream infection (CR-BSI). Patients admitted to an intensive care unit were prospectively assigned to have a CVC and AC connected with either a needle-free valve connection system (NFVCS) or a three-way stopcock connection (3WSC). The characteristics of the patients were similar in the two groups. Before manipulation, the NFVCS was disinfected with chlorhexidine digluconate 0.5% alcoholic solution. The 3WSC was not disinfected between use but it was covered with a protection cap. A total of 799 patients requiring the insertion of a multilumen CVC or AC for >48h from 1 April 2002 to 31 December 2003 were included. CR-BSI rates were 4.61 per 1000 days of catheter use in the disinfected NFVCS group and 4.11 per 1000 days of catheter use in the 3WSC group (P=0.59). When CVC-BSIs and AC-BSIs were analysed separately, the rate of CVC-BSI was 4.26 per 1000 days of catheter use in the NFVCS group, compared with 5.27 in the 3WSC group (P=0.4). The incidence rate of AC-BSI was 5.00 per 1000 days of catheter use in the NFVCS group, compared with 2.83 in the 3WSC group (P=0.08). The use of NFVCS does not reduce the incidence of catheter-related bacteraemia. The arterial catheter (AC) is a significant source of infection in critically ill patients.

Lectin-gated and glycan functionalized mesoporous silica nanocontainers for targeting cancer cells overexpressing Lewis X antigen.

Gated mesoporous silica nanoparticles can deliver payload upon the application of a predefined stimulus, and therefore are promising drug delivery systems. Despite their important role, relatively low emphasis has been placed on the design of gating systems that actively target carbohydrate tumor cell membrane receptors. We describe herein a new Lewis X (Lex) antigen-targeted delivery system comprising mesoporous silica nanoparticles (MSNs) loaded with ATTO 430LS dye, functionalized with a Lex derivative (1) and capped with a fucose-specific carbohydrate-binding protein (Aleuria aurantia lectin (AAL)). This design takes advantage of the affinity of AAL for Lex overexpressed receptors in certain cancer cells. In the proximity of the cells, AAL is detached from MSNs to bind Lex, and selectins in the cells bind Lex in the gated MSNs, thereby inducing cargo delivery. Gated MSNs are nontoxic to colon cancer DLD-1 cells, and ATTO 430LS dye delivered correlated with the amount of Lex antigen overexpressed at the DLD-1 cell surface. This is one of the few examples of MSNs using biologically relevant glycans for both capping (via interaction with AAL) and targeting (via interaction with overexpressed Lex at the cell membrane).

The serum level of xenoantibodies, and hDAF or alphaGAL expression on pig cells, modulate in vitro the protection given by hDAF to primate complement-mediated damage.

The ability of human complement regulatory molecules to prevent xenograft rejection following pig-to-primate xenotransplantation is limited. We assayed the efficacy of transgenic human decay accelerating factor (hDAF) expressed on porcine cells to inhibit the in vitro complement activity of primate sera. We measured the cytotoxic activity of baboon or human sera against peripheral blood lymphocytes (PBLs) from hDAF or nontransgenic pigs using a flow cytometry complement-mediated cytotoxicity assay (FCCA). We also analyzed the anti-Galalpha1-3Gal (alphaGal) antibody titer of the baboon sera by ELISA and the expression of hDAF and alphaGal on the PBL surface by immunofluorescence. Transgenic hDAF expression was capable of protecting pig cells against injury produced by both baboon and human serum. However, the hDAF molecule was more efficient against human than baboon sera. The humoral cytotoxicity capacity correlated with the level of both IgG and IgM anti-alphaGal antibodies. In addition, inhibition of complement-mediated cytotoxicity of hDAF pig cells correlated with the expression of hDAF and alphaGal molecules on target cells. These results confirm in vitro the protective role of hDAF in pig cells to heterologus complement mediated damage, but they also suggest that protection decreases in the presence of high levels of anti-porcine antibodies in serum, low expression of hDAF, or high expression of alphaGal on pig cells.

Predictors of long-term mortality in patients with cirrhosis undergoing cardiac surgery.

AIM: Little is known regarding the long-term outcome in cirrhotic patients undergoing cardiac surgery. The objective of this study was to identify preoperative and postoperative mortality risk factors and to determine the best predictors of long-term outcome. METHODS: Fifty-eight consecutive cirrhotic patients requiring cardiac surgery between January 2004 and January 2009 were prospectively studied at our institution. Seven patients (12%) died. A complete follow-up was performed in the whole survival group until November 2012 (mean 46±28 months). Variables usually measured on admission and during the first 24 h of the postoperative period were evaluated together with cardiac surgery scores (Parsonnet, EuroSCORE), liver scores (Child-Turcotte-Pugh, Model for End-Stage Liver Disease, United Kingdom End-Stage Liver Disease score), and ICU scores (Acute Physiology and Chronic Health Evaluation II and III, Simplified Acute Physiology Score II and III, Sequential Organ Failure Assessment). RESULTS: Twelve patients (23.5%) died during follow-up; six were Child class A and six class B. Comparing survivors vs. non-survivors using univariate analysis, variables associated with better long-term outcome were lower arterial lactate 24 h after admission (1.7±0.4 vs. 2.1±0.7 mmol·L(-1), P=0.03) and higher urine output in the first 24 h (2029±512 vs. 1575±627 mL, P=0.03). The receiver operating characteristic curve showed that the Simplified Acute Physiology Score III score had the best predictive value for long-term outcome (AUC: 77.4±0.76%; sensitivity: 83.3%; specificity: 64.9%, P=0.005). Multivariate analysis identified Simplified Acute Physiology Score III score (P=0.02) and urine output in the first 24 h (P=0.02) as independent factors associated with long-term outcome. Long-term survival was 82.4% for Child A, 47.6% for Child B and 33.3% for Child C (P=0.001). CONCLUSION: Long-term survival in cirrhotic patients requiring cardiac surgery is a more valuable prognostic measure than short-term survival. Urine output in the first 24 h may be a valuable predictor of long-term outcome in these patients. The Simplified Acute Physiology Score III is also useful.

Incidence and risk factors associated with the development of cytomegalovirus disease after intestinal transplantation.

From May 1990 to March 1993, 38 patients (21 adults and 17 children) received 40 allografts that included the small bowel (14 isolated small bowel, 21 small bowel and liver, and 5 multivisceral transplantations). Fifteen patients (39%) had 26 episodes of CMV disease: 7 with one episode, 6 with two, and 1 each with three and four. CMV enteritis accounted for 21 (81%) of the episodes, hepatitis and pneumonitis for 2 each, and a viral syndrome for 1. Cox's proportional hazards univariate and multivariate analyses showed that significant first-episode risk factors were: CMV seropositive donors for negative recipients (relative risk [RR], 3.86; P = 0.02), the average daily plasma trough level of tacrolimus (RR, 2.15; P = 0.04), and total amount of steroid boluses (RR, 2.90; P = 0.02). CMV disease recurrence factors were: CMV seronegative recipients (RR, 8.60; P = 0.02) and total amount of steroid bolus pulses (RR, 12.39; P = 0.004). Because long courses of ganciclovir prophylaxis could not prevent the development of CMV disease, avoidance of CMV seropositive grafts in seronegative recipients and new strategies to prevent heavy immunosuppression without the penalty of rejection will be necessary to ameliorate this problem in intestinal transplant recipients.

Hamster to rat kidney xenotransplantation. Effects of FK 506, cyclophosphamide, organ perfusion, and complement inhibition.

Hamster to rat renal xenotransplantation was performed with recipient nephrectomies. Recipients were treated beginning on day 0 with continuous FK 506 monotherapy, a 7-day or open-ended monotherapeutic course of cyclophosphamide (CP), and the two drug regimens combined. CP alone (10 mg/kg/day) prevented a xenospecific antibody response and tripled median survival of the kidney (defined as recipient death) from 6 (control) to 18.5 days whereas FK 506 alone had no effect. The drugs in combination were no better than CP alone (15 days) unless the 5-day course of CP was given at a higher dose (15 mg/kg) and started 3 days preoperatively (79 days). In further experiments, adjuvant measures were added to the minimally effective FK 506/7-day CP regimen which gave a median survival of only 15 days. In the most successful modification, intraoperative antibody depletion by the temporary transplantation of third party hamster liver or en bloc kidneys increased median survival from 15 to 34 and 48 days, respectively. An intraoperative i.v. dose administration of the anticomplement drug K76 instead of antibody depletion increased survival to 26 days. Although the events of kidney rejection were similar to those of heart xenografts and partially forestalled by the antibody inhibiting CP treatment, or by antibody depletion, survival for > 100 days was accomplished in only 5 of 86 treated animals. The poorer survival previously reported with cardiac xenotransplantation is largely explained by the life support requirement of the kidneys. Renal failure was responsible for almost all deaths before 60 days, and subnormal renal failure was a pervasive adverse factor thereafter, frequently caused by pyelonephritis which is suspected to have had an immunologic etiology.

Effect of anticomplement agent K76 COOH on hamster-to-rat and guinea pig-to-rat heart xenotransplantation.

In normal rats, the xenobiotic K76 inhibited the C5 and probably the C2 and C3 steps of complement and effectively depressed classical complement pathway activity, alternative complement pathway activity, and the C3 complement component during and well beyond the drug's 3-hr half-life. It was tested alone and with intramuscular tacrolimus (TAC) and/or intragastric cyclophosphamide (CP) in rat recipients of heterotopic hearts from guinea pig (discordant) and hamster (concordant) donors. Single prevascularization doses of 100 and 200 mg/kg increased the median survival time of guinea pig hearts from 0.17 hr in untreated controls to 1.7 hr and 10.2 hr, respectively; with repeated injections of the 200-mg dose every 9-12 hr, graft survival time was increased to 18.1 hr. Pretreatment of guinea pig heart recipients for 10 days with TAC and CP, with or without perioperative splenectomy or infusion of donor bone marrow, further increased median graft survival time to 24 hr. Among the guinea pig recipients, the majority of treated animals died with a beating heart from respiratory failure that was ascribed to anaphylatoxins. Hamster heart survival also was increased with monotherapy using 200 mg/kg b.i.d. i.v. K76 (limited by protocol to 6 days), but only from 3 to 4 days. Survival was prolonged to 7 days with the addition of K76 of intragastric CP at 5 mg/kg per day begun 1 day before operation (to a limit of 9 days); it was prolonged to 4.5 days with the addition of intramuscular TAC at 2 mg/kg per day beginning on the day of transplantation and continued indefinitely. In contrast to the limited efficacy of the single drugs, or any two drugs in combination, the three drugs together (K76, CP, and TAC) in the same dose schedules increased median graft survival time to 61 days. Antihamster antibodies rapidly increased during the first 5 days after transplantation, and plateaued at an abnormal level in animals with long graft survival times without immediate humoral rejection. However, rejection could not be reliably prevented, and was present even in most of the xenografts recovered from most of the animals dying (usually from infection) with a beating heart. Thus, although effective complement inhibition with K76 was achieved in both guinea pig- and hamster-to-rat heart transplant models, the results suggest that effective interruption of the complement cascade will have a limited role, if any, in the induction of xenograft acceptance.

A prospective randomized trial comparing sequential ganciclovir-high dose acyclovir to high dose acyclovir for prevention of cytomegalovirus disease in adult liver transplant recipients.

Cytomegalovirus disease is an important cause of morbidity following liver transplantation. To date there has not been an effective prophylaxis for CMV disease after liver transplantation. One hundred forty-three patients were randomized to receive either high dose oral acyclovir (800 mg 4 times a day) alone for 3 months after transplantation (acyclovir group) or intravenous ganciclovir (5 mg/kg twice a day) for 14 days followed by high dose oral acyclovir to complete a 3-month regimen (ganciclovir group). Of 139 patients available for evaluation, 43 of 71 (61%) patients from the acyclovir group developed CMV infection compared with 16 of 68 (24%) from the ganciclovir group (relative risk, 3.69; 95% confidence interval, 2.07-6.56; P < 0.00001). Of those randomized, CMV disease was seen in 20 (28%) of the acyclovir group compared with 6 (9%) of the ganciclovir group (relative risk, 5.11; 95% confidence interval, 2.05-12.75; P = 0.0001). The median time to onset of CMV infection was 45 days in the acyclovir group compared with 78 days in the ganciclovir group (P = 0.004). The median time to onset of CMV disease was 40 days in the acyclovir group compared with 78 days in the ganciclovir patients (P = 0.02). With respect to primary CMV infection, there was no difference in the rates in the 2 groups, but tissue invasive disease and recurrent CMV disease were less frequent in the ganciclovir group. It is concluded that a course of 2 weeks of ganciclovir immediately after transplantation followed by high dose oral acyclovir for 10 weeks is superior to a 12-week course of high dose oral acyclovir alone for prevention of both CMV infection and CMV disease after liver transplantation. However, the lack of significant effect in seronegative recipients who received grafts from seropositive donors suggests that other strategies are needed to prevent CMV infection in this high risk population.

The influence of HLA matching on cytomegalovirus hepatitis and chronic rejection after liver transplantation.

Previous findings in liver transplantation patients have raised the concept that HLA plays a dualistic role. HLA matching will reduce rejection but may augment MHC restricted cellular immune mechanisms of liver allograft injury. To evaluate this concept, we studied CMV hepatitis in 399 FK506-treated liver transplant patients, including 355 cases for which complete HLA-A,B,DR,DQ typing information was available. CMV hepatitis developed in 25 patients, and 17 of them (or 68%) showed a one or two HLA-DR antigen match with the donor. In contrast, HLA-DR matches were found in only 35% of 330 patients without CMV hepatitis (P = 0.005). No significant associations were seen for HLA-A, HLA-B, and HLA-DQ antigens. In pretransplant CMV-seronegative patients with seropositive grafts (n = 39), the frequency of CMV hepatitis was 44% for HLA-DR-matched livers but 14% for HLA-DR-unmatched livers. In seropositive recipients (n = 187), these frequencies were 12% and 2% for HLA-DR-matched and unmatched liver grafts. Chronic rejection developed in 29 patients (or 8%) during a follow-up between 10 and 24 months after transplantation. Its incidence was higher in the CMV hepatitis group (24% vs. 6%) (P = 0.007). Although no associations were found between HLA matching and the incidence of chronic rejection, there was an earlier onset of chronic rejection of HLA-DR-matched livers irrespective of CMV hepatitis. These findings suggest that an HLA-DR match between donor and recipient increases the incidence of CMV hepatitis in both primary and secondary CMV infections. Although HLA compatibility leads to less acute cellular rejection, it is suggested that DR matching may accelerate chronic rejection of liver transplants, perhaps through HLA-DR-restricted immunological mechanisms toward viral antigens, including CMV.

Goals for transplantation in the new millennium.

Presentations at the XVIII International Congress of the Transplantation Society covered all key organ-specific and subspecialty areas of transplantation. Highlights were sessions under the auspices of two new sections of the Society, the International Xenotransplantation Association and the Section on Transplant Infectious Disease.

Basic and patient-oriented research in organ transplantation.

The first joint congress of the American Society of Transplant Surgeons (ASTS) and the American Society of Transplantation (AST)--TRANSPLANT 2000--, was held May 13-17, 2000, in Chicago, Illinois, U.S.A. Results were presented on the latest clinical advances in organ transplantation, as well as aspects of basic research, where genetics studies and gene therapy approaches are gaining in importance. In the clinic, immunosuppressants continue to play a key role in transplantation, and the appearance of new drugs (e.g., mycophenolate mofetil, sirolimus) in recent years has led to increased possibilities of combination regimens, some including as many as four drugs. First clinical studies with three new immunosuppressants--FTY-720, leflunomide and rituximab) were also presented. The stellar presentation at TRANSPLANT 2000 was of a trial of pancreatic islet transplantation in type-1 diabetic patients which led to sustained insulin independence.