Infectious agents after liver transplant: etiology, timeline and patients' cell-mediated immunity responses

Applicability of common inflammatory markers in diagnosing infections in early period after liver transplantation in intensive care setting

Infections remain an important cause of morbidity and mortality early after liver transplantation. The aim of this prospective longitudinal study was to evaluate clinical utility of c-reactive protein (CRP), procalcitonin, and neutrophil-to-lymphocyte ratio (NLR) in surveillance of infections early after liver transplantation in intensive care setting. A total of 60 liver transplant recipients were included. CRP, procalcitonin, and NLR assessed at 12-hour intervals were primary variables of interest. Infections and severe complications during postoperative intensive care unit stay were the primary and secondary end-points, respectively. Infections and severe complications were diagnosed in 9 and 17 patients, respectively. Only peak CRP beyond first 48 hours was associated with infections (p = 0.038) with AUC, positive and negative predictive value of 0.728, 42.9% and 92.2%, respectively (cut-off: 142.7 mg/L). Peak procalcitonin over first 60 hours was the earliest predictor (p = 0.050) of severe complications with AUC, positive and negative predictive value of 0.640, 53.3% and 80.0%, respectively (cut-off: 42.8 ng/mL). In conclusion, while CRP, procalcitonin, and NLR cannot be used for accurate diagnosis of infections immediately after liver transplantation, peak CRP beyond 48 hours and peak procalcitonin over first 60 hours may be used for initial exclusion of infections and prediction of severe complications, respectively.

Clinical relevance of a CD4+ T cell immune function assay in the diagnosis of infection in pediatric living-donor liver transplantation

The aim of the present study was to investigate the potential of the Immuknow immune cell function assay for the diagnosis of infection after pediatric living-donor liver transplantation (LDLT). Based on clinical data obtained following liver transplantation, 66 patients were divided into infection (n=28) and non-infection (n=38) groups. The following factors were considered in the present analysis: Primary disease, lymphocyte count, tacrolimus plasma concentration/dose (C0/D) ratio, CD4+ T lymphocyte ATP levels, at pre-transplant stage and at weeks 1-4, and 2 and 3 months post-transplant. The CD4+ T lymphocyte ATP values were plotted in a receiver operating characteristic (ROC) curve. The CD4+ T lymphocyte ATP value of the infection group was significantly lower compared with that of the non-infection group (188.6±93.5 vs. 424.4±198.1 ng/ml, respectively; P<0.05). No correlation was observed between the ATP value and tacrolimus plasma C0/D ratio (R2=0.0001484); however, a correlation was reported between the ATP value and lymphocyte count (R2=0.2149). Analysis of the ROC curve indicated that the ATP levels of CD4+ T cells were significantly associated with the diagnostic value of infection (area under the curve=0.866). These findings suggest that low CD4+ T lymphocyte ATP levels may be an independent risk factor for infection following pediatric LDLT, and that the Immuknow assay may be used as a tool to evaluate T lymphocyte function in such patients to predict the risk of infection.

Immune function as predictor of infectious complications and clinical outcome in patients undergoing solid organ transplantation (the ImmuneMo:SOT study): a prospective non-interventional observational trial

Background

Solid organ transplantation (SOT) is a well-established and life-saving treatment for patients with end-stage organ failure. Organ rejection and infections are among the main complications to SOT and largely determines the clinical outcome. The correct level of immunosuppression is of major importance to prevent these complications. However, it is a consistent observation that in recipients on the same immunosuppressive regimens the clinical outcome varies, and no reliable marker exists to monitor immune function.

Methods

In a prospective, observational study, we plan to enroll 630 adult patients with a planned organ transplantation at Rigshospitalet, University of Copenhagen, Denmark. Prior to and on different time points up to two years after transplantation we will perform a complete immunological profile on the recipients. This profile will consist of classical descriptive immune phenotyping (flow cytometry and circulating biomarkers) and the functional assay TruCulture®. In TruCulture® whole blood is incubated ex vivo with stimulants imitating bacterial, viral and fungal infections, where after a panel of selected cytokines is quantified. Clinical data from electronic health records will be obtained from the PERSIMUNE (Centre of Excellence for Personalized Medicine of Infections Complications in Immune Deficiency at Rigshospitalet, Copenhagen) data repository, a warehouse of data generated as part of routine care including vital signs, biochemistry, microbiology, pathology as well as medication, demographics, diagnoses, hospital contacts, surgical procedures and mortality.

Discussion

This will be the first large scale study to determine several aspects of immune function and perform a complete immunological profiling in SOT recipients. It is expected that knowledge generated will provide information to generate prediction models identifying patients at increased risk of infection and/or rejection. If the study is successful, we will subsequently use the generated prediction models to propose personalized immunosuppressive regimens to be tested in future randomized controlled trials.

Trial registration

This study has been approved by the Regional ethical committee (H-17024315), the Danish Data Protection Agency (RH-2016-47, RH-2015-04, I-Suite 03605) and the Danish National board of Health (3–3013-1060/1). The trial is retrospectively registered at clinicaltrials.gov (NCT03847285) the 20th February 2019.

Infections in live donor liver transplant recipients: A study of timeline, aetiology and antimicrobial resistance of bacterial and fungal infections from the developing world

Infections are the leading cause of morbidity and mortality in liver transplant (LT) recipients. We studied timeline, spectrum of infection, system involved, and antimicrobial resistance in 64 patients undergoing live donor LT with 6-month follow-up. Of 64 patients, 38 (59.5%) patients had 103 infectious episodes, 10 patients had single infectious episode and 28 patients had two or more infectious episodes. 96 (93.2%) were bacterial and Candida infections were in 7 (6.8%). Early phase had 30 (29.1%) episodes; intermediate phase 25 (24.2%) and late phase 48 (46.6%). Mortality was 11/64 (17.1%). Knowledge of timeline, aetiological agent and antimicrobial resistance is useful to guide empirical therapy and infection prevention.