Assessing hepatic steatosis by magnetic resonance in potential living liver donors.

PURPOSE: To determine the accuracy of magnetic resonance imaging-proton density fat fraction (MRI-PDFF) measurements for detecting liver fat content in potential living liver donors and to compare these results using liver biopsy findings. METHODS: A total of 139 living liver donors (men/women: 83/56) who underwent MRI between January 2017 and September 2021 were included in this analysis retrospectively. The PDFFs were measured using both MR spectroscopy (MRS) and chemical shift-based MRI (CS-MRI) for each donor in a blinded manner. RESULTS: Significant positive correlations were found between liver biopsy and MRS-PDFF and CS-MRI PDFF in terms of hepatic steatosis detection [r = 0.701, 95% confidence interval (CI): 0.604-0.798, r = 0.654, 95% CI: 0.544-0.765, P < 0.001, respectively). A weak level correlation was observed between liver biopsy, MRI methods, and vibration-controlled transient elastography attenuation parameters in 42 available donors. Based on receiver operating characteristic (ROC) analysis, MRS-PDFF and CS-MRI PDFF significantly distinguished >5% of histopathologically detected hepatic steatosis with an area under the ROC curve (AUC) of 0.837 ± 0.036 (P < 0.001, 95% CI: 0.766-0.907) and 0.810 ± 0.036 (P < 0.001, 95% CI: 0.739-0.881), respectively. The negative predictive values (NPVs) of MRS-PDFF and CS-MRI PDFF were 88.3% and 81.3%, respectively. In terms of distinguishing between clinically significant hepatic steatosis (≥10% on histopathology), the AUC of MRS-PDFF and CS-MRI were 0.871 ± 0.034 (P < 0.001 95% CI: 0.804-0.937) and 0.855 ± 0.036 (P < 0.001, 95% CI: 0.784-0.925), respectively. The NPVs of MRS-PDFF and CS-MRI were 99% and 92%, respectively. CONCLUSION: The methods of MRS-PDFF and CS-MRI PDFF provide a non-invasive and accurate approach for assessing hepatic steatosis in potential living liver donor candidates. These MRI PDFF techniques present a promising clinical advantage in the preoperative evaluation of living liver donors by eliminating the requirement for invasive procedures like liver biopsy.

BNT162b2 or CoronaVac as the Third Dose against Omicron: Neutralizing Antibody Responses among Transplant Recipients Who Had Received Two Doses of CoronaVac.

We evaluated neutralizing antibodies against the Omicron variant and Anti-Spike IgG response in solid organ (SOT) or hematopoietic stem cell (HSTC) recipients after a third dose of BNT162b2 (BNT) or CoronaVac (CV) following two doses of CV. In total, 95 participants underwent SOT (n = 62; 44 liver, 18 kidney) or HSCT (n = 27; 5 allogeneic, 22 autologous) were included from five centers in Turkey. The median time between third doses and serum sampling was 154 days (range between 15 to 381). The vaccine-induced antibody responses of both neutralizing antibodies and Anti-Spike IgGs were assessed by plaque neutralizing assay and immunoassay, respectively. Neutralizing antibody and Anti-Spike IgG levels were significantly higher in transplant patients receiving BNT compared to those receiving CV (Geometric mean (GMT):26.76 vs. 10.89; p = 0.03 and 2116 Au/mL vs. 172.1 Au/mL; p < 0.001). Solid organ transplantation recipients, particularly liver transplant recipients, showed lower antibody levels than HSCT recipients. Thus, among HSCT recipients, the GMT after BNT was 91.29 and it was 15.81 in the SOT group (p < 0.001). In SOT, antibody levels after BNT in kidney transplantation recipients were significantly higher than those in liver transplantation recipients (GMT: 48.32 vs. 11.72) (p < 0.001). Moreover, the neutralizing antibody levels after CV were very low (GMT: 10.81) in kidney transplantation recipients and below the detection limit (<10) in liver transplant recipients. This study highlights the superiority of BNT responses against Omicron as a third dose among transplant recipients after two doses of CV. The lack of neutralizing antibodies against Omicron after CV in liver transplant recipients should be taken into consideration, particularly in countries where inactivated vaccines are available in addition to mRNA vaccines.

Effect of Pretransplant Infections on Clinical Outcomes in Live-Donor Liver Transplant Recipients.

Owing to impaired immune function, surgical procedures, and multiple hospitalizations, patients with end-stage liver disease are at risk for numerous infectious complications while waiting for transplantation. Infection in transplant recipients remains the main cause of mortality and morbidity, despite advances in surgical techniques and the development of new repressive agents. The purpose of this study is to examine the infections that develop during the pretransplantion period in live donor liver transplant recipients and their effect on post-transplant clinical outcomes. The retrospective analysis of adult live donor liver transplant recipients in the last 4 years was conducted at Ankara University Hospital, a 1900-bed tertiary-care university hospital, in Ankara, Turkey. Demographic characteristics, preoperative infections, and clinical outcomes were analyzed. Patients were divided into 2 groups according to whether they had developed an infection before transplantation. The diagnoses were based on clinical, laboratory, and microbiological findings. Statistical analyses were performed using Stata version 9.0 (StataCorp, College Station, Tex., United States), and P < .05 were considered statistically significant. In univariate analyses, having diabetes mellitus or a pretransplant infection, the number of pretransplant infection attacks, the need for a reoperation, and developing a post-transplant infection were the statistically significant factors associated with 1-year mortality (P < .001, χ2 test). In multivariate analyses, diabetes mellitus (Odds ratio [OR] = 7.44, 95% confidence interval [CI], .03-45.79; P = .013), reoperation (OR = .33, 95% CI, .25-2.20; P < .001), having a pretransplantation infection (OR = 12.47, 95% CI, .011-87.67; P = .013), and the number of pretransplantation infection attacks (OR = .028, 95% CI, .013-.47; P < .001) were found to be statistically significant risk factors for 1-year mortality. Our study showed the effect of pretransplantation infections on post-transplant morbidity but not on rejection or mortality. According to the situation of patients, manageable pretransplantation infection is not an absolute contraindication for liver transplantation. Awareness of the increased risk for post-transplant infections and fast-acting antimicrobial coverage are the most important facts for patient survival.

Carbapenemase-Producing Bacterial Infections in Patients With Liver Transplant.

Carbapenemase-producing Enterobacteriacea (CPE) cause serious and life-threatening infections. They are resistant to carbapenems and many other classes of commonly used antimicrobial agents; therefore, managing infections caused by them poses a substantial challenge in clinical practice. They can also cause morbidity and mortality in patients with liver transplant. A retrospective analysis of CPE culture-positive patients with a history of liver transplant can help to examine the epidemiology and microbiology of these bacteria, as well as gain information on the possible infection sources, susceptibility patterns, and expected mortality in infected populations. In addition, study of these bacteria could help formulate a consensus on the appropriate use of empirical and directed antibiotic therapy, which can effectively reduce infections in these patients. We reviewed the medical records of 142 subjects who underwent liver transplantation at Ankara University Hospital, a 1900-bed tertiary care university hospital, in Ankara, Turkey, between January 2014 and August 2018. Patients showing signs of infection with culture positivity for CPE-producing organisms were included from the study. Statistical analysis was performed and a value of P < .05 is considered statistically significant. In most cases, the source of infection was the abdomen. Klebsiella species was also predominant in these cases. Model for End-Stage Liver Disease scores and length of hospital stay were higher and statistically significant when compared to patients who were CPE negative. Mortality was highest in the CPE-positive group. Infection is the most important cause of mortality and morbidity after liver transplantation and increases the cost of treatment. Regarding the culture sensitivity patterns and resistance mode, empirical therapy with carbapenems does not produce a solid result. The high mortality observed with these infections reflects very limited therapeutic options.