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To assess the utility of spleen stiffness as a diagnostic tool in individuals with human immunodeficiency virus (HIV) and non-cirrhotic portal hypertension (NCPH).The Philips EPIQ7, a new point shearwave elastography (pSWE) technique, was used to assess liver and spleen stiffness in 3 patient groups. Group 1: HIV and NCPH (n = 11); Group 2: HIV with past didanosine (ddI) exposure without known liver disease or NCPH (n = 5); Group 3: HIV without known liver disease or ddI exposure (n = 9).Groups were matched for age, HIV chronicity, and antiretroviral treatment (including cumulative ddI exposure in Groups 1 and 2). Differences in liver and spleen stiffness (in kPa) between groups were analyzed using the Mann-Whiney U test.Liver and spleen stiffness were both significantly higher in NCPH versus ddI-exposed (P = .019 and P = .006) and ddI-unexposed controls (P = .038 and P < .001). Spleen stiffness was more effective than liver stiffness at predicting NCPH, area under receiver operating characteristic (AUROC) 0.812 versus 0.948. Combining the 2 variables improved the diagnostic performance, AUROC 0.961. The optimal cut-off for predicting NCPH using splenic stiffness was 25.4 kPa, with sensitivity 91%, specificity 93%, positive predictive value (PPV) 91%, negative predictive value (NPV) 93%, positive likelihood ratio 12.73, negative likelihood ratio 0.10. Spleen and liver stiffness scores were strongly correlated (P = .0004, 95% confidence interval [CI] 18, 59).Elevated spleen stiffness is observed in HIV with NCPH and can be quantified easily using pSWE with high diagnostic accuracy. Novel strategies such as pSWE for longitudinal monitoring of patients with HIV and NCPH should be considered.

Background: Neuroinflammation plays an important role in HIV-associated neurological disorders; however, its role prior to the onset of symptomatic disease is unclear. We imaged microglial activation, the hallmark of neuroinflammation, in asymptomatic HIV-infected patients on effective combination ART., Methods: Seven neurologically and cognitively asymptomatic adults with chronic HIV-infection and nine healthy volunteers were investigated with [11C]-PK11195 PET, a marker of translocator protein (TSPO) expressed by activated microglia. In the HIV-infected patients, cognitive speed, accuracy and executive function were also assessed. Between-group differences in [11C]-PK11195 binding potential were localized throughout the brain with statistical parametric mapping (SPM) and associations between levels of [11C]-PK11195 binding and cognitive performance were interrogated using linear regression modelling., Results: In HIV-infected patients, Statistical parametric mapping detected clusters of significantly increased [11C]-PK11195 binding in corpus callosum (P = 0.001), anterior cingulate (P = 0.001), posterior cingulate (P = 0.008) and temporal (P = 0.026) and frontal (P = 0.038) areas. Cognitive functions were intact in the HIV group, however, a significant association between greater [11C]-PK11195 binding and poorer executive function performance was observed in the anterior cingulate (P = 0.031), corpus callosum and posterior cingulate (P = 0.001)., Conclusion: Despite effective control of HIV infection, neuroinflammation, as evidenced by the presence of focal cortical areas of activated microglia, occurs in asymptomatic HIV-infected patients and levels correlate with poorer executive performance. Further studies are needed to establish whether detection of activated microglia in HIV-infected patients represents a marker of future neurocognitive decline.

Objective: To measure changes in psychometric state, neural activation, brain volume (BV), and cerebral metabolite concentrations during treatment of minimal hepatic encephalopathy., Methods: As proof of principle, 22 patients with well-compensated, biopsy-proven cirrhosis of differing etiology and previous minimal hepatic encephalopathy were treated with oral l-ornithine l-aspartate for 4 weeks. Baseline and 4-week clinical review, blood chemistry, and psychometric evaluation (Psychometric Hepatic Encephalopathy Score and Cognitive Drug Research Score) were performed. Whole-brain volumetric and functional MRI was conducted using a highly simplistic visuomotor task, together with proton magnetic resonance spectroscopy of the basal ganglia. Treatment-related changes in regional BV and neural activation change (blood oxygenation level dependent) were assessed., Results: Although there was no change in clinical, biochemical state, basal ganglia magnetic resonance spectroscopy, or in regional BV, there were significant improvements in Cognitive Drug Research Score (+1.2, p = 0.003) and Psychometric Hepatic Encephalopathy Score (+1.5, p = 0.003) with treatment. This cognitive amelioration was accompanied by changes in blood oxygenation level-dependent activation in the posterior cingulate and ventral medial prefrontal cortex, 2 regions that form part of the brain's structural and metabolic core. In addition, there was evidence of greater visual cortex activation., Conclusions: These structurally interconnected regions all showed increased function after successful encephalopathy treatment. Because no regional change in BV was observed, this implies that mechanisms unrelated to astrocyte volume regulation were involved in the significant improvement in cognitive performance.

Numerous studies have reported associations between chronic hepatitis C virus (HCV) infection and fatigue, depression and impairments in health-related quality of life, which are independent of the severity of liver disease. Although there are a large number of potential explanations for these symptoms, including a history of substance abuse and associated personality types, or the effect of the diagnosis of HCV infection itself, there has been recent interest in the possibility of a biological effect of HCV infection on cerebral function. There is emerging evidence of mild, but significant neurocognitive impairment in HCV infection, which cannot be wholly attributed to substance abuse, co-existent depression or hepatic encephalopathy. Impairments are predominantly in the domains of attention, concentration and information processing speed. Furthermore, in-vivo cerebral magnetic resonance spectroscopy studies in patients with hepatitis C and normal liver function have reported elevations in cerebral choline-containing compounds and reductions in N-acetyl aspartate, suggesting that a biological mechanism may underlie the cognitive findings. The recent detection of HCV genetic sequences in post-mortem brain tissue raises the intriguing possibility that HCV infection of the central nervous system may be related to the reported neuropsychological symptoms and cognitive impairment.

Background: Organ cold storage times may be extended by modifications to organ preservation solutions., Methods: Three preservation solutions were investigated for their ability to maintain viable hepatic bioenergetics in stored pig livers: modified University of Wisconsin (mUW); mUW+adenosine (1.34 g/L), and mUW+ iloprost (10(-8)mol/L), a prostacyclin analogue. Using human liver retrieval and storage techniques, pig livers were stored on ice for either 2 or 16 hr, after which phosphorus-31 spectra were collected every 2 min during the period of cold ischemia and hypothermic reperfusion (HtR). During HtR, metabolite concentration changes associated with phosphomonoesters, inorganic phosphate, gamma-nucleotide triphosphate (NTP), and beta-NTP were measured for all solutions., Results: After a 2-hr storage, beta-NTP regeneration in mUW+iloprost produced +57.7% (P<0.01) more beta-NTP, at a faster initial rate of +66.3% (P<0.001), compared with mUW, and mUW+adenosine regenerated +35.6% (P<0.05) more beta-NTP, compared with mUW. Storage for 16 hr did not slow the rates of regeneration, and the total NTP produced during the course of the experiment remained unchanged for the respective preservation solutions. Cessation of HtR invoked a net accumulation of nucleotide diphosphate, indicating differential kinetics of adenine nucleotide hydrolysis., Conclusion: This large animal model study suggests significant improvements to human organ preservation solutions using prostacyclin analogues and adenosine with respect to hepatic bioenergetics.

The aim of this study was to assess the possibility of regenerating nucleotide triphosphates (NTP) in the pig liver following its harvest and subsequent storage on ice. This study has used a pig model that allowed human donor liver retrieval techniques and methods of storage to be utilized. In vitro phosphorus-31 nuclear magnetic resonance (31P-NMR) spectroscopy was used to evaluate the changes associated with phosphorus containing metabolites such as NTP, phosphomonoesters (PME), phosphodiesters (PDE), and inorganic phosphate (Po). During 4 hr storage NTP levels were reduced to undetectable levels but its regeneration was possible over a period of 2 hr of oxygenated hypothermic reperfusion. Resynthesized NTP reached values that were only 30% reduced from pre-harvest values. There was a corresponding reduction in Pi over the same period. Glycolytic intermediates, 3-phosphoglycerate and 2,3 diphosphoglycerate, both increased significantly during the period of storage and subsequently declined following hypothermic reperfusion. Cellular damage, indicated by the concentrations of glycerophosphorylcholine (GPC) and glycerophosphorylethanolamine (GPE) was minimal during cold storage. However upon hypothermic reperfusion, concentrations of GPC and GPE reduced, indicating a degree of cellular damage caused by reperfusion. This study has shown for the first time that is possible to regenerate high energy phosphate nucleotides following a period of hypothermic reperfusion in a large, clinically related animal model. This technique warrants investigation clinically to improve the outcome of orthotopic liver transplantation. It also provides a method to study the effects of different preservation fluids and methods of storage and organ reperfusion.