ABSTRACT Hepatic encephalopathy (HE) is a common complication of advanced liver disease causing brain dysfunction. This is likely due to the accumulation of unfiltered toxins within the bloodstream. A known risk factor for developing or worsening HE is the placement of a transjugular intrahepatic portosystemic shunt (TIPS), which connects the pre-hepatic and post-hepatic circulation allowing some blood to bypass the dysfunctional liver and decreases portal hypertension. To better understand the pathophysiology of post-TIPS HE, we conducted a multi-center prospective cohort study employing metabolomic analyses on hepatic vein and peripheral vein blood samples from participants with cirrhosis undergoing elective TIPS placement, measuring chemical modifications and changes in concentrations of metabolites resulting from TIPS placement. In doing so, we identified numerous alterations in metabolites, including bile acids, glycerophosphocholines, and bilirubins possibly implicated in the development and severity of HE.
Of the approximately one in 1000 pregnant women who develop the syndrome of hemolysis, elevated liver enzymes, and low platelets (HELLP), 2 to 3 per cent develop hepatic complications, including liver failure for which liver transplantation (LT) may be required. Between February 1, 1984, and December 31, 2006, eight women without a history of liver disease underwent LT for complications of HELLP syndrome. All received cadaveric grafts with a mean interval from delivery to LT of 7 days. The mean admission Child-Turcotte-Pugh score was 13.1 (class C), and the mean model for end-stage liver disease score was 40. Manifestations of liver failure included encephalopathy (seven patients), renal failure (four), disseminated intravascular coagulation (three), and respiratory failure (one). There were no intraoperative deaths. Complications of LT included biliary leaks (three patients), reoperation (three), and retransplantation (two). There was one death from sepsis on postoperative day 91 and one death from cholangitis/sepsis more than 5 years postoperatively. After LT, 1-, 5-, and 10-year patient survival rates were 88 per cent, 88 per cent, and 65 per cent; 1-, 5-, and 10-year graft survival rates were 64 per cent, 64 per cent, and 48 per cent. This is the largest single-center report of LT for HELLP. Early recognition and transfer to a transplant center will yield best results with this challenging complication of pregnancy.
Background. To investigate the impact of intrapatient variability (IPV) in the levels of immunosuppressant drugs on health outcomes after liver transplantation. Methods. A comprehensive systematic review and meta-analysis were conducted, examining literature from MEDLINE/PubMed, Embase, Web of Science, Cochrane Reviews, and Cochrane CENTRAL. Results. The analysis focused on acute rejection, graft survival, acute kidney injury, and cancer risk as health outcomes. Of 2901 articles screened, 10 met the inclusion criteria. The results indicate a 19% reduction in the risk of acute rejection in patients with lower IPV (RR = 0.81; 95% confidence interval, 0.66-0.99), although 6 studies found no significant association between high IPV and acute rejection. Contrasting results were observed for graft survival, with 1 study indicating worse outcomes for high IPV, whereas another reported no significant difference. High IPV was consistently associated with acute kidney injury across 3 studies. One study suggested a link between high IPV and hepatocellular carcinoma, although a meta-analysis for these outcomes was not feasible. Conclusions. These findings point to a marginal but statistically significant association between high IPV and an increased risk of acute rejection, highlighting the importance of precise management of immunosuppressive drugs in liver transplant recipients to enhance patient outcomes.
The two identical genomic RNA strands inside each HIV‐1 viral particle are linked through homodimerization of an RNA stem‐loop, termed SL1, near their 5′ ends. SL1 first dimerizes through a palindromic sequence in its loop, forming a transient kissing‐loop complex which then refolds to a mature, linear duplex. We previously reported the NMR structure of a 23‐base truncate of SL1 in kissing‐dimer form, and here report the high‐resolution structure of its linear isoform. This structure comprises three short duplex regions – derived from the central palindrome and two stem regions of each strand, respectively – separated by two bulges that each encompass three unpaired adenines flanking the palindromes. The stacking pattern of these adenines differs from that seen in the kissing‐loop complex, and leads to greater colinear base stacking overall. Moreover, the mechanical distortion of the palindrome helix is reduced, and base pairs ruptured during formation of the kissing‐loop complex are re‐established, so that all potential Watson‐Crick pairs are intact. These features together likely account for the greater thermodynamic stability of the mature dimer as compared to its kissing‐loop precursor.
Immunosuppression after liver transplantation is essential for preventing allograft rejection. However, long-term drug toxicity and associated complications necessitate investigation of immunosuppression minimization and withdrawal protocols. Development of such protocols is hindered by reliance on current paradigms for monitoring allograft function and rejection status. The current standard of care for diagnosis of rejection is histopathologic assessment and grading of liver biopsies in accordance with the Banff Rejection Activity Index. However, this method is limited by cost, sampling variability, and interobserver variation. Moreover, the invasive nature of biopsy increases the risk of patient complications. Incorporating noninvasive techniques may supplement existing methods through improved understanding of rejection causes, hepatic spatial architecture, and the role of idiopathic fibroinflammatory regions. These techniques may also aid in quantification and help integrate emerging -omics analyses with current assessments. Alternatively, emerging noninvasive methods show potential to detect and distinguish between different types of rejection while minimizing risk of adverse advents. Although biomarkers have yet to replace biopsy, preliminary studies suggest that several classes of analytes may be used to detect rejection with greater sensitivity and in earlier stages than traditional methods, possibly when coupled with artificial intelligence. Here, we provide an overview of the latest efforts in optimizing the diagnosis of rejection in liver transplantation.
ABSTRACT Background Inter- and intra-individual variability in tacrolimus dose requirements mandates empirical clinician-titrated dosing that frequently results in deviation from a narrow target range. Improved methods to individually dose tacrolimus are needed. Our objective was to determine whether a quantitative, dynamically-customized, phenotypic-outcome-guided dosing method termed Phenotypic Personalized Medicine (PPM) would improve target drug trough maintenance. Methods In a single-center, randomized, pragmatic clinical trial ( NCT03527238 ), 62 adults were screened, enrolled, and randomized prior to liver transplantation 1:1 to standard-of-care (SOC) clinician-determined or PPM-guided dosing of tacrolimus. The primary outcome measure was percent days with large (>2 ng/mL) deviation from target range from transplant to discharge. Secondary outcomes included percent days outside-of-target-range and mean area-under-the-curve (AUC) outside-of-target-range per day. Safety measures included rejection, graft failure, death, infection, nephrotoxicity, or neurotoxicity. Results 56 (29 SOC, 27 PPM) patients completed the study. The primary outcome measure was found to be significantly different between the two groups. Patients in the SOC group had a mean of 38.4% of post-transplant days with large deviations from target range; the PPM group had 24.3% of post-transplant days with large deviations; (difference -14.1%, 95% CI: -26.7 to -1.5 %, P=0.029). No significant differences were found in the secondary outcomes. In post-hoc analysis, the SOC group had a 50% longer median length-of-stay than the PPM group [15 days (Q1-Q3: 11-20) versus 10 days (Q1-Q3: 8.5-12); difference 5 days, 95% CI: 2-8 days, P=0.0026]. Conclusions PPM guided tacrolimus dosing leads to better drug level maintenance than SOC. The PPM approach leads to actionable dosing recommendations on a day-to-day basis. Lay Summary In a study on 62 adults who underwent liver transplantation, researchers investigated whether a new dosing method called Phenotypic Personalized Medicine (PPM) would improve daily dosing of the immunosuppression drug tacrolimus. They found that PPM guided tacrolimus dosing leads to better drug level maintenance than the standard-of-care clinician-determined dosing. This means that the PPM approach leads to actionable dosing recommendations on a day-to-day basis and can help improve patient outcomes.
