Dysregulated expression of T-helper cell responses and susceptibility to infections in high-risk liver transplant recipients

Preoperative hypoalbuminaemia in liver surgery: an observational study at a university medical centre

OBJECTIVES

Preoperative hypoalbuminaemia is associated with adverse outcome, including increased postoperative mortality in cardiovascular surgery, neurosurgery, trauma and orthopaedic surgery. However, much less is known about the association between preoperative serum albumin and clinical outcomes after liver surgery. In this study, we sought to determine whether hypoalbuminaemia before partial hepatectomy is associated with a worse postoperative outcome.

DESIGN

Observational study.

SETTING

University Medical Centre in Germany.

PARTICIPANTS

We analysed 154 patients enrolled in the perioperative PHYsostigmine prophylaxis for liver resection patients at risk for DELIrium and postOperative cognitive dysfunction (PHYDELIO) trial with a preoperative serum albumin assessment. Hypoalbuminaemia was defined as serum albumin <35 g/L. Subgroups classified as hypoalbuminaemia and non-hypoalbuminaemia consisted of 32 (20.8%) and 122 (79.2%) patients, respectively.

OUTCOME MEASURES

The outcome parameters of interest were postoperative complications according to Clavien (moderate: I, II; major: ≥III), length of intensive care unit (ICU) stay, length of hospital stay and survival rates 1 year after surgery.

RESULTS

Preoperative hypoalbuminaemia was associated with the occurrence of major postoperative complications (OR 3.051 (95% CI 1.197 to 7.775); p=0.019) after adjusting for age, sex, randomisation, American Society of Anesthesiologists physical status, preoperative diagnosis and Child-Pugh class. Both ICU and hospital lengths of stay were significantly prolonged in patients with preoperative hypoalbuminaemia (OR 2.573 (95% CI 1.015 to 6.524); p=0.047 and OR 1.296 (95% CI 0.254 to 3.009); p=0.012, respectively). One-year survival was comparable between patients with and without hypoalbuminaemia.

CONCLUSIONS

We found that low serum albumin before surgery was associated with a worse short-term outcome after partial hepatectomy, which strengthens the prognostic value of serum albumin in the setting of liver surgery.

TRIAL REGISTRATION NUMBERS

ISRCTN18978802 and EudraCT 2008-007237-47.

T cell cytokine signatures: Biomarkers in pediatric multiple sclerosis

Although multiple sclerosis is predominantly regarded as a disease of young adulthood, up to 5% of MS patients are diagnosed prior to age eighteen. The predominant form of MS is relapsing-remitting characterized by exacerbations of symptoms followed by periods of remission. The majority of disease modifying drugs target T cell proliferation or block migration into the central nervous system. Although these treatments reduce relapses, disease progression still occurs, warranting therapeutic strategies that protect the CNS. Biomarkers to indicate relapses would facilitate a personalized approach for add-on therapies that protect the CNS. A multiplex cytokine bead array was performed to detect T cell associated cytokines in sera from patients 6-20years of age with pediatric onset MS clinically diagnosed in relapse or remission compared to healthy control patients. Of the 25 cytokines evaluated, 17 were increased in patients clinically diagnosed in relapse compared to sera from control patients in contrast to only 9 cytokines in the clinically diagnosed remission group. Furthermore, a linear regression analysis of cytokine levels in the remission population showed 12 cytokines to be statistically elevated as a function of disease duration, with no effect observed in the relapse population. To further explore this concept, we used a multivariable stepwise discriminate analysis and found that the following four cytokines (IL-10, IL-21, IL-23, and IL-27) are not only a significant predictor for MS, but have important predictive value in determining a relapse. Since IL-10 and IL-27 are considered anti-inflammatory and IL-21 and IL-23 are pro-inflammatory, ratios of these cytokines were evaluated using a Duncan's multiple range test. Of the six possible combinations, increased ratios of IL-10:IL-21, IL-10:IL-23, and IL-10:IL-27 were significant suggesting levels of IL-10 to be a driving force in predicting a relapse.

Hypoalbuminemia Within Two Postoperative Days Is an Independent Risk Factor for Acute Kidney Injury Following Living Donor Liver Transplantation: A Propensity Score Analysis of 998 Consecutive Patients

OBJECTIVE

Acute kidney injury is a known major complication of liver transplantation. Previous reports have shown that hypoalbuminemia is associated with an increased risk of acute kidney injury. However, little is known about the relationship between the early postoperative albumin level and acute kidney injury after living donor liver transplantation. The aim of this study was to identify the influence of the postoperative albumin level on acute kidney injury prevalence after living donor liver transplantation.

DESIGN

A retrospective analysis.

SETTING

A tertiary care university hospital.

PATIENTS

Nine hundred and ninety-eighty patients underwent living donor liver transplantation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We divided the enrolled patients into two groups: group 1 included patients whose postoperative albumin level was less than 3.0 g/dL (n = 522), and group 2 included patients with an albumin level greater than or equal to 3.0 g/dL (n = 476). The prevalence of acute kidney injury, major adverse cardiac events, hospital stay, ICU stay, 30-day mortality, and overall mortality was analyzed using inverse probability of treatment weighting and propensity-score matching (n = 249 pairs) analysis. The prevalence of acute kidney injury was higher in group 1 defined by both Acute Kidney Injury Network (after adjusting for inverse probability of treatment weighting [n = 364; 69.7%] and propensity-score matching [n = 152; 61.0%]) and Risk, Injury, Failure, Loss, and End-stage kidney disease criteria (after adjusting for inverse probability of treatment weighting [n = 419; 80.3%] and propensity-score matching [n = 190; 76.3%]). The overall mortality was higher in group 1 after adjusting for inverse probability of treatment weighting (n = 61; 11.7%) and propensity-score matching (n = 23; 9.2%). The hospital (p < 0.001) and ICU (p = 0.006) stays were significantly prolonged in group 1. Acute kidney injury was associated with ICU stay by the Acute Kidney Injury Network criteria (p = 0.034), and overall mortality was correlated with acute kidney injury by the Risk, Injury, Failure, Loss, and End-stage kidney disease criteria (p = 0.014).

CONCLUSIONS

Early postoperative hypoalbuminemia is an independent risk factor for acute kidney injury, and postoperative acute kidney injury is related to postoperative ICU stay and overall mortality after living donor liver transplantation.

Preoperative factors associated with postoperative requirements of renal replacement therapy following cardiac surgery

Renal dysfunction is a major adverse event after cardiovascular surgery. Therefore, the preoperative prediction of which patients will require renal replacement therapy (RRT) after cardiac surgery is an important issue. In the present study, 1,822 consecutive patients who underwent cardiovascular surgery from 2008 and 2013 at a single institution were reviewed. Patients who were already receiving long-term hemodialysis before surgery (n = 134) were excluded. The remaining 1,688 patients were separated into 2 groups: those requiring postoperative RRT and those without RRT requirement. A total of 128 patients (7.6%) required RRT. Patients requiring RRT had greater perioperative blood loss, longer intubation time, and longer hospital stays (p <0.0001 for all). Multivariate analysis revealed that cardiopulmonary bypass use, preoperative body surface area, the left ventricular ejection fraction, serum albumin, and creatinine were independent risk factors for postoperative RRT (odds ratios 2.435, 0.204, 0.976, 0.556, and 5.394, 95% confidence intervals 1.471 to 4.140, 0.054 to 0.841, 0.962 to 1.025, 0.363 to 0.860, and 3.671 to 8.223, respectively, p <0.05 for all). A subgroup of patients with relatively preserved renal function before surgery (creatinine <1.12 mg/dl, a cut-off value for RRT requirement obtained from receiver-operating characteristic curve analysis [area under the curve 0.74748, sensitivity 60.2%, specificity 85.0%]) showed that preoperative serum albumin concentration was most significantly associated with postoperative RRT requirement (odds ratio 0.048, 95% confidence interval 0.023 to 0.095, p <0.0001). In conclusion, cardiopulmonary bypass use, preoperative renal impairment as reflected by elevated creatinine level, small body size, a low left ventricular ejection fraction, and hypoalbuminemia were associated with a requirement for postoperative RRT. In patients with preserved renal function, hypoalbuminemia was most significantly related to requirement for RRT.

Preoperative serum albumin levels predict 1-year postoperative survival of patients undergoing heart transplantation

BACKGROUND

Serum albumin concentration has been recognized as a marker of nutrition, severity of inflammation, and hepatic function in patients with various chronic diseases. The purpose of this study was to investigate the impact of pretransplant serum albumin concentration on post-transplant outcome in heart transplant recipients.

METHODS AND RESULTS

Preoperative laboratory variables, including albumin concentration and donor-related information, were obtained from 822 consecutive patients undergoing heart transplant at Columbia University Medical Center between 1999 and 2010. The association between pretransplant albumin concentration and post-transplant 1-year survival was analyzed. Available data from the United Network for Organ Sharing (n=13671) were also analyzed to evaluate the impact of preoperative albumin levels on post-transplant outcome. In our cohort, multivariable analysis revealed that preoperative albumin (mg/dL; hazard ratio, 0.46; P<0.0001) and preoperative total bilirubin (mg/dL; hazard ratio, 1.26; P=0.0002) were associated with post-transplant 1-year mortality. This implied that for every 1 mg/dL increase in albumin concentration, the post-transplant 1-year mortality rate decreased by 54%. The Kaplan-Meier analysis based on our patients cohort and the United Network for Organ Sharing dataset showed lower survival rate at 1-year post-transplant in patients with albumin levels ≤ 3.5 mg/dL compared with those with >3.5 mg/dL (our patients, 91.3 versus 72.4%; P<0.0001; United Network for Organ Sharing, 88.4 versus 84.8%; P<0.0001).

CONCLUSIONS

Pretransplant serum albumin concentration is a strong prognostic marker for post-transplant survival in heart transplant recipients.

Invasive fungal infection after liver transplantation: risk factors and significance of immune cell function monitoring

OBJECTIVE

Monitoring immune status in transplant recipients is essential for predicting the risk of infections. The aims of the study were to identify the correlation of a low ImmuKnow adenosine triphosphate (ATP) value with the development of invasive fungal infections (IFIs) and whether this is an independent risk factor for IFIs in liver recipients.

METHODS

We followed up 248 liver recipients who developed 157 infectious episodes. Peripheral CD4(+) T cells were selected freshly for ATP detection. Percentages of T-helper (Th, CD3(+) CD4(+) ) and T-suppressor (Ts, CD3(+) CD8(+) ) lymphocyte subgroups were also examined.

RESULTS

Overall 44 patients (17.7%) were diagnosed as IFIs, of whom 9 (20.5%) died. The average ImmuKnow ATP value in the IFI patients (109 ± 78 ng/mL) was significantly lower than that in common bacterial infections (174 ± 106 ng/mL, P < 0.01) or stable liver recipients (314 ± 132 ng/mL, P < 0.01), while there was no difference in the Th/Ts ratio among each group. Logistic regression analysis showed ImmuKnow ATP value less than 100 ng/mL was an independent risk factor of IFI (OR = 3.44, P = 0.0237). ImmuKnow ATP values had no correlation with lymphocytes or their subgroups, but tended to correlate with the number of neutrophils and total white blood cells.

CONCLUSIONS

ImmuKnow assay monitoring has the potential to identify the patients at risk of developing IFI after liver transplantation (LT), which may provide a feasible measure for optimizing liver recipients' immune cellular function after transplantation.

Impact of the duration of posttransplant renal replacement therapy on bacterial infections in liver transplant recipients

Whether the duration of renal replacement therapy (RRT) after liver transplantation influences the rate and types of bacterial infections is not known. In this study, 47 of 299 consecutive liver transplant recipients (16%) required posttransplant RRT. The incidence of bacterial infections was higher in the RRT group versus the non-RRT group (8.84 versus 1.38 per 1000 patient days, P < 0.001). In the RRT group, 49% of the patients (23/47) required long-term RRT (≥30 days), and 51% (24/47) required short-term RRT (<30 days). Long-term RRT (hazard ratio = 2.27, 95% confidence interval = 1.16-4.47, P = 0.017) was a significant predictor of infections. Bacteremia and intra-abdominal infections were the most common sources of infections, and Enterobacteriaceae and enterococci were the predominant pathogens in both groups. The mortality rate for patients requiring RRT was higher than the rate for patients not requiring RRT (P < 0.001), but the mortality rates of the short-term RRT group and the long-term RRT group did not significantly differ (P = 0.654). In conclusion, although both short-term RRT and long-term RRT confer a higher risk of bacterial infections, only long-term RRT is a statistically significant predictor of these infections.

T-helper 17 cell: A distinctive cell in liver diseases

T-helper (Th)17 cells, a new population of effector CD4(+) T cells, are characterized by the secretion of interleukin (IL)-17. It has been demonstrated that Th17 cells are distinct from Th1 and Th2 cells; they play important roles in the pathogenesis of numerous inflammatory and autoimmune diseases; and are closely related to host defense, tumorigenesis and transplant rejection. Moreover, it has been found that these cells have a close and intricate connection with the regulatory T cells, which play an important role in maintaining self-tolerance and down-tuning immune responses. In the present review, we find that they are significantly elevated in various kinds of liver diseases including liver autoimmunity and inflammatory diseases, alcoholic liver disease and hepatocellular carcinoma.

Pretransplant lymphocyte count predicts the incidence of infection during the first two years after liver transplantation

Patients with end-stage liver disease (ESLD) show a low absolute number of peripheral blood lymphocyte subpopulations (PBLSs). We investigated if the baseline PBLS could categorize orthotopic liver transplantation (OLT) recipients into groups at high or low risk for infection after transplantation. PBLSs were prospectively studied in 63 consecutive patients (42 males; mean age +/- standard deviation: 53.5 +/- 10.3 years) with ESLD prior to OLT. Thirty-five patients (55.6%) developed a total of 79 infectious episodes during the first 2 years post-OLT. The median total lymphocyte count and PBLS levels [CD3+ T cells, CD4+ T cells, memory (CD45RO+) CD4+ T cells, T cell receptor alphabeta+ and gammadelta+ subsets, and CD19+ B cells] at baseline were significantly lower in patients with an infection compared with those without one (P < 0.05). There was a significant correlation between the risk of development of a post-OLT infection and a baseline total lymphocyte count < 1.00 x 10(3)/microL (P = 0.001), a baseline CD3+ T cell count < 0.75 x 10(3)/microL (P = 0.009), and a baseline CD4+ T cell count < 0.5 x 10(3)/microL (P = 0.008). In the multivariate analysis, this association between the baseline total lymphocyte level and infection remained significant (odds ratio: 10.1; 95% confidence interval: 1.9-39.5). In conclusion, the pre-OLT total lymphocyte count identifies a subset of patients at high risk for infection. PBLS monitoring prior to OLT may offer an opportunity for surveillance, tapering of immunosuppression, and preemptive therapy.