Validation of a novel point-of-care test for alanine aminotransferase measurement: A pilot cohort study.

BACKGROUND: Alanine aminotransferase (ALT) measurement is essential for evaluation of liver disease. We validated a novel rapid point-of-care (POC) test for ALT1 against laboratory ALT. METHODS: Stored plasma samples from adults with chronic liver disease (Test cohort n = 240; Validation cohort n = 491) were analysed using the BioPoint® antigen immunoassay POC ALT1 lateral flow test, which provides quantitative ALT results (Axxin handheld reader) or semi-quantitative results (visual read, cut off 40 IU/ml). The accuracy of POC ALT1 to detect ALT > 40 IU/L was determined by ROC analysis. In patients with chronic hepatitis B, treatment eligibility (EASL criteria) was determined using POC ALT1 and compared to laboratory ALT. RESULTS: POC ALT1 test had good accuracy for laboratory ALT > 40 IU/L: AUROC 0.93 (95% CI: 0.89-0.96) in the Test cohort and AUROC 0.92 (95% CI: 0.88-0.95) in the Validation cohort. POC ALT1 cut off of 0.8 for ALT > 40 IU/L maximised sensitivity (97%) and specificity (71%) in the Test cohort (42% laboratory ALT > 40 IU/L) and yielded PPV 84% and NPV 91% in the Validation cohort (19% laboratory ALT > 40 IU/L). Semi-quantitative POC ALT1 had good accuracy for laboratory ALT in the Validation cohort (AUROC 0.85, 95% CI: 0.81-0.99; sensitivity 77% and specificity 93%). Combined with HBV DNA and transient elastography, both quantitative and semi-quantitative POC ALT1 tests had good accuracy for excluding hepatitis B treatment needs (sensitivity 96%, specificity 78% and NPV 99%). CONCLUSION: The POC ALT1 test had good accuracy for elevated ALT levels and for determining treatment eligibility among people with chronic hepatitis B.

Diabetes IN hospital - Glucose and Outcomes in the COVID-19 pandemic (DINGO COVID-19): the 2020 Melbourne hospital experience prior to novel variants and vaccinations.

BACKGROUND AND AIMS: A relationship between diabetes, glucose and COVID-19 outcomes has been reported in international cohorts. This study aimed to assess the relationship between diabetes, hyperglycaemia and patient outcomes in those hospitalised with COVID-19 during the first year of the Victorian pandemic prior to novel variants and vaccinations. DESIGN, SETTING: Retrospective cohort study from March to November 2020 across five public health services in Melbourne, Australia. PARTICIPANTS: All consecutive adult patients admitted to acute wards of participating institutions during the study period with a diagnosis of COVID-19, comprising a large proportion of patients from residential care facilities and following dexamethasone becoming standard-of-care. Admissions in patients without known diabetes and without inpatient glucose testing were excluded. RESULTS: The DINGO COVID-19 cohort comprised 840 admissions. In 438 admissions (52%), there was no known diabetes or in-hospital hyperglycaemia, in 298 (35%) patients had known diabetes, and in 104 (12%) patients had hyperglycaemia without known diabetes. ICU admission was more common in those with diabetes (20%) and hyperglycaemia without diabetes (49%) than those with neither (11%, P < 0.001 for all comparisons). Mortality was higher in those with diabetes (24%) than those without diabetes or hyperglycaemia (16%, P = 0.02) but no difference between those with in-hospital hyperglycaemia and either of the other groups. On multivariable analysis, hyperglycaemia was associated with increased ICU admission (adjusted odds ratio (aOR) 6.7, 95% confidence interval (95% CI) 4.0-12, P < 0.001) and longer length of stay (aOR 173, 95% CI 11-2793, P < 0.001), while diabetes was associated with reduced ICU admission (aOR 0.55, 95% CI 0.33-0.94, P = 0.03). Neither diabetes nor hyperglycaemia was independently associated with in-hospital mortality. CONCLUSIONS: During the first year of the COVID-19 pandemic, in-hospital hyperglycaemia and known diabetes were not associated with in-hospital mortality, contrasting with published international experiences. This likely mainly relates to hyperglycaemia indicating receipt of mortality-reducing dexamethasone therapy. These differences in published experiences underscore the importance of understanding population and clinical treatment factors affecting glycaemia and COVID-19 morbidity within both local and global contexts.

Hepatitis B Virus Flares After Nucleot(s)ide Analogue Cessation Are Associated With Activation of Toll-Like Receptor Signaling Pathways.

BACKGROUND: We evaluated the patterns of peripheral Toll-like receptor (TLR) signaling activity and the expression of TLRs and natural killer (NK) cell activation in a cohort of patients experiencing severe hepatitis flares after stopping nucleot(s)ide analogues (NAs) therapy. METHODS: Samples were collected longitudinally from patients with chronic hepatitis B who were enrolled in a prospective study of NA discontinuation. Patients experiencing hepatitis flares were compared with patients with normal alanine aminotransferase. Peripheral blood mononuclear cells (PBMCs) were stimulated with TLR ligands and cytokine secretion in the cell culture supernatant measured. Expression of TLR2/4, NKG2D, NKp46, and triggering receptor expressed on myeloid cells 1 (TREM-1) on monocytes, NK, and NK-T cells was measured. RESULTS: Seventeen patients with severe reactivation hepatitis flares were compared to 12 nonflare patients. Hepatitis flares were associated with increased activity of TLR2-8 and TLR9 signaling in PBMCs at the time of peak flare compared to baseline. Hepatitis flares were also associated with (1) upregulation of TLR2 and (2) TREM-1 receptor expression on NK. There were no differences at baseline between flare patients and nonflare patients. CONCLUSIONS: Hepatitis flares off NA therapy have a significant innate inflammatory response with upregulation of TLR signaling on peripheral monocytes and TLR2 and TREM-1 expression on NK cells. This implicates the innate immune system in the immunopathogenesis of hepatitis B flares.

Discontinuation of nucleot(s)ide analogue therapy in HBeAg-negative chronic hepatitis B: a meta-analysis.

BACKGROUND AND AIMS: Sustained virological suppression and hepatitis B surface antigen (HBsAg) loss have been described after nucleot(s)ide analogue (NA) discontinuation for patients with hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (CHB). We performed a meta-analysis of the clinical outcomes after NA discontinuation for HBeAg-negative CHB. METHODS: Studies involving NA cessation in HBeAg-negative CHB individuals with a median follow-up of ≥12 months were included. Participants were HBeAg-negative at the time of NA initiation. Random effects meta-analyses were performed for the following clinical outcomes: (1) virological relapse (VR) at 6 and 12 months; (2) clinical relapse (CR) at 6 and 12 months and (3) HBsAg loss. Effect of other variables was estimated using subgroup analysis and meta-regression. Studies including patients stopping entecavir (ETV) and/or tenofovir disoproxil fumarate (TDF) were considered separately to studies including patients stopping older generation NA. RESULTS: N=37 studies met inclusion criteria. Cumulative incidence of VR and CR after stopping ETV/TDF was 44% and 17% at 6 months and 63% and 35% at 12 months. Similar relapse rates were observed after stopping older NAs. Among patients stopping ETV/TDF, TDF cessation was associated with increased CR rates at 6 months versus ETV. There was an association between follow-up ≥4 years and HBsAg loss rates when stopping older NAs. Hepatic decompensation and hepatocellular carcinoma were rare but occurred more frequently in studies including cirrhotic individuals. CONCLUSION: VR is common after NA discontinuation, however, CR was only seen in one-third of patients at 12 months. Stopping NA therapy can be followed by HBsAg clearance, and rates are higher with longer follow-up.

Assessment of the cobas® HBV RNA investigational assay in the setting of nucleoside analog therapy cessation.

HBV RNA is used as a marker of cccDNA transcription and is applicable in the setting of nucleos(t)ide analog (NA) treatment, which suppresses HBV DNA. Traditional assays for quantification of HBV RNA rely on labor-intensive 3'RACE assays targeting the polyA tail. In this study, the high-throughput Roche cobas®HBV RNA investigational assay was assessed on the Roche cobas® 6800 automated platform. Of 969 samples collected for a NA treatment cessation trial, and tested on the cobas assay, 249 were analyzed for sensitivity, reproducibility, sample type applicability, and results were compared to a RACE-based assay. Results of 97 paired serum and plasma samples demonstrated an excellent correlation of 0.98. However, 14.5% of plasma samples yielded detectable (below the limit of quantification) results, when the paired serum was undetectable, and plasma was shown to yield a statistically significant (p < 0.001) greater mean 0.119 log10 copies/ml. Quantification of 152 samples showed good correlation (0.91) between the cobas and RACE assays. The cobas assay demonstrated superior lower limit of quantification, 10 copies/ml, which resulted in detection of 13.2% more samples than the RACE assay. Reproducibility and linear range of the automated assay were also confirmed. The Roche cobas assay for HBV RNA is sensitive and highly recommended.

Safety, Pharmacokinetics, and Pharmacodynamics of the Oral TLR8 Agonist Selgantolimod in Chronic Hepatitis B.

BACKGROUND AND AIMS: In patients with chronic hepatitis B (CHB) infection, activation of toll-like receptor 8 may induce antiviral immunity and drive functional cure. Selgantolimod, a toll-like receptor 8 agonist, was evaluated in patients with CHB who were virally suppressed on oral antiviral treatment or viremic and not on oral antiviral treatment. APPROACH AND RESULTS: In this phase 1b study, patients were randomized 4:1 to receive either selgantolimod or placebo once weekly. Virally suppressed patients received either 1.5 mg (for 2 weeks) or 3 mg (for 2 weeks or 4 weeks). Viremic patients received 3 mg for 2 weeks. The primary endpoint was safety, as assessed by adverse events (AEs), laboratory abnormalities, and vital sign examination. Pharmacokinetic and pharmacodynamic parameters were assessed by plasma analysis. A total of 38 patients (28 virally suppressed, 10 viremic) were enrolled from six sites in Australia, New Zealand, and South Korea. Twenty patients (53%) experienced an AE and 32 (84%) had laboratory abnormalities, all of which were mild or moderate in severity. The most common AEs were headache (32%), nausea (24%), and dizziness (13%). With a half-life of 5 hours, no accumulation of selgantolimod was observed with multiple dosing. Selgantolimod induced transient dose-dependent increases in serum cytokines, including IL-12p40 and IL-1RA, which are important for the expansion and activity of multiple T- cell subsets and innate immunity. CONCLUSION: Selgantolimod was safe and well-tolerated in virally suppressed and viremic patients with CHB and elicited cytokine responses consistent with target engagement. Further studies with longer durations of selgantolimod treatment are required to evaluate efficacy.

A qualitative exploration of enablers for hepatitis B clinical management among ethnic Chinese in Australia.

An estimated 18% of people living with chronic hepatitis B (CHB) in Australia were born in China. While guideline-based care, including regular clinical monitoring and timely treatment, prevent CHB-related cirrhosis, cancer and deaths, over three-quarters of people with CHB do not receive guideline-based care in Australia. This qualitative study aimed to identify enablers to engagement in CHB clinical management among ethnic Chinese people attending specialist care. Participants self-identified as of Chinese ethnicity and who attended specialist care for CHB clinical management were interviewed in Melbourne in 2019 (n = 30). Semi-structured interviews covered experiences of diagnosis and engagement in clinical management services, and advice for people living with CHB. Interviews were recorded with consent; data were transcribed verbatim and thematically analysed. Receiving clear information about the availability of treatment and/or the necessity of long-term clinical management were the main enablers for participants to engage in CHB clinical management. Additional enablers identified to maintain regular clinical monitoring included understanding CHB increases risks of cirrhosis and liver cancer, using viral load indicators to visualize disease status in patient-doctor communication; expectations from family, peer group and medical professionals; use of a patient recall system; availability of interpreters or multilingual doctors; and largely subsidized healthcare services. In conclusion, to support people attending clinical management for CHB, a holistic response from community, healthcare providers and the public health sector is required. There are needs for public health programmes directed to communicate (i) CHB-related complications; (ii) availability of effective and cheap treatment; and that (iii) long-term engagement with clinical management and its benefits.

The QuantiFERON Monitor® assay is predictive of infection post allogeneic hematopoietic cell transplantation.

INTRODUCTION: Following allogeneic hematopoietic stem cell transplantation (alloHCT), excessive immunosuppression can be complicated by infection, while inadequate immunosuppression can result in graft-vs-host disease (GVHD). An accurate method to assess overall immune status post HCT is lacking. The QuantiFERON Monitor® (QFM) assay measures interferon gamma (IFN-γ) release from whole blood following incubation with both innate (Toll-like receptor 7, TLR7) and adaptive (CD3 antibody) stimulants and may result in a more complete assessment of the immune system. METHODS: Whole blood samples were prospectively collected from alloHCT recipients at conditioning followed by days 10, 30, 60, 90, 120, and 180 post-transplant and assayed by the QFM test. IFN-γ levels were correlated to time post HCT and episodes of infection and GVHD. RESULTS: Forty patients were enrolled in the study (68% male; median age 47 years; 58% matched related donors, 42% unrelated; 33% myeloablative). Post-stimulation IFN-γ levels rose steadily over the first 180 days post transplantation. IFN-γ levels were significantly lower in those with active infection compared to those without during the neutropenic period (P < .001). The assay was predictive of CMV reactivation (VL > 1000 copies/mL) post alloHCT (P = .001). CONCLUSION: This is a promising assay to demonstrate immune recovery and predict risk of infection after alloHCT and may allow tailoring of immunosuppression, antimicrobial treatment, and prophylaxis.

Clinical variation in the use of echocardiography in Staphylococcus aureus bacteraemia: a multi-centre cohort study.

The objective of this investigation was to assess whether between-hospital variation in echocardiography usage for patients with Staphylococcus aureus bacteraemia (SAB) is explained by differences in patients' pre-test probability of endocarditis. This was a retrospective cohort study at three neighbouring hospitals in Australia. Consecutive episodes of SAB were reviewed for the presence of three endocarditis risk factors (community onset, prolonged bacteraemia and the presence of an intracardiac prosthetic device) and the performance and results of all echocardiography studies within 30 days. Multivariate logistic regression was used to examine the effect of hospital site on the performance of (i) transoesophageal and (ii) transthoracic echocardiography controlling for major endocarditis risk factors. Significant variation in echocardiography usage was demonstrated between sites in a total cohort of 1167 episodes of SAB. None of the three sites were found to exhibit echocardiography usage that could be considered consistent with current guidelines, and each differed from the guidelines in different ways. Hospital site, rather than endocarditis risk factors, was the strongest predictor of transthoracic echocardiography use; however, the use of transoesophageal echocardiography was strongly predicted by endocarditis risk factors. Variation in echocardiography use between these hospitals is not adequately explained by differences in the risk factor profile of their SAB cohorts.

A novel immune function biomarker identifies patients at risk of clinical events early following liver transplantation.

Balancing immunosuppression after liver transplant is difficult, with clinical events common. We investigate whether a novel immune biomarker based on a laboratory platform with widespread availability that measures interferon γ (IFNγ) after stimulation with a lyophilized ball containing an adaptive and innate immune stimulant can predict events following transplantation. A total of 75 adult transplant recipients were prospectively monitored in a blinded, observational study; 55/75 (73.3%) patients experienced a total of 89 clinical events. Most events occurred within the first month. Low week 1 results were significantly associated with risk of early infection (area under the receiver operating characteristic curve [AUROC], 0.74; P = 0.008). IFNγ ≤ 1.30 IU/mL (likelihood ratio positive, 1.93; sensitivity, 71.4%; specificity, 63.0%) was associated with the highest risk for infection with minimal rejection risk. Nearly half the cohort (27/60, 45.0%) expressed IFNγ ≤ 1.30 IU/mL. Moreover, an elevated week 1 result was significantly associated with the risk of rejection within the first month after transplant (AUROC, 0.77; P = 0.002), but no episodes of infection. On multivariate logistic regression, IFNγ ≥ 4.49 IU/mL (odds ratio, 4.75) may be an independent predictor of rejection (P = 0.05). In conclusion, low IFNγ suggesting oversuppression is associated with infections, whereas high IFNγ indicating undersuppression is associated with rejection. This assay offers the potential to allow individualization and optimization of immunosuppression that could fundamentally alter the way patients are managed following transplantation. Liver Transplantation 23 487-497 2017 AASLD.

Toll-like Receptor Expression and Signaling in Peripheral Blood Mononuclear Cells Correlate With Clinical Outcomes in Acute Hepatitis C Virus Infection.

BACKGROUND: Mechanisms by which spontaneous clearance of acute hepatitis C occurs are unclear. A critical role for the innate immune system and IFNL4 polymorphisms has been proposed. This study investigates whether Toll-like receptor (TLR) expression and signaling during acute hepatitis C correlates with clinical outcomes. METHODS: Participants identified from the Australian Trial in Acute Hepatitis C and the Networks study were followed longitudinally from the time of diagnosis of acute hepatitis C. Peripheral blood mononuclear cells (PBMCs) and plasma were collected at and 2 time points after diagnosis. At each time point, TLR2, TLR4, and CD86 expression on peripheral blood monocytes, natural killer (NK) cells, and NK T cells was measured, as well as the response of PBMCs to stimulation with TLR ligands. Cytokine and chemokine levels were measured in stimulated PBMCs and plasma. RESULTS: We identified 20 participants with acute hepatitis C (10 with hepatitis C virus [HCV] monoinfection and 10 with HCV and human immunodeficiency virus coinfection). Eleven participants (55%) spontaneously cleared HCV. Acute hepatitis C and spontaneous clearance was associated with lower TLR4 expression on monocytes (P = .009) and NK cells (P = .029). Acute hepatitis C and spontaneous clearance was also associated with a reduced interferon γ response to TLR4 (P = .038) and TLR7/8 stimulation (P = .035), a reduced interleukin 6 response to TLR7/8 stimulation (P = .037), and reduced IFN-γ-inducible protein 10 (IP-10) response to TLR2 stimulation (P = .042). Lower plasma IP-10 levels were associated with spontaneous clearance (P = .001). CONCLUSIONS: These findings implicate TLR4 signaling as playing a critical role in the outcome of acute hepatitis C.

Managing HBV in pregnancy. Prevention, prophylaxis, treatment and follow-up: position paper produced by Australian, UK and New Zealand key opinion leaders.

Hepatitis B during pregnancy presents unique management issues for both the mother and fetus. These include the lack of a current cohesive strategy for treatment and follow-up of mothers and their babies; the uncertain risk of postpartum HBV flares; the lack of randomised trial data on the safety and efficacy of antiviral treatment in pregnancy; the lack of head-to-head studies comparing different antivirals in pregnancy; and the lack of epidemiologic information regarding infection across different populations globally. This position paper provides a comprehensive review of the management of women with HBV infection prior to conception, throughout each stage of pregnancy and postpartum, as well as recommendations and clinical approaches for the follow-up of children born to infected mothers, based on available evidence in the literature and recommendations from international experts. Prevention of perinatal transmission is an important component of global efforts to reduce the burden of chronic HBV since vertical transmission is responsible for most of the chronic infection worldwide.

Clinical and virological predictors of hepatic flares in pregnant women with chronic hepatitis B.

BACKGROUND: Unique immunological changes occur during pregnancy; the impact of which, on virological and biochemical markers of hepatitis B infection is not well established. Rapid changes in the immunological profile post partum and consequent rebound of the inflammatory response may result in hepatic flares. METHODS: Women with chronic hepatitis B were recruited during pregnancy into this observational study. Demographic and clinical data were collected together with virological and biochemical parameters at two time points during pregnancy (early and late) and two time points post partum (between 6 weeks and 12 weeks and at 12 months). Outcomes analysed included changes in HBV DNA, hepatitis B e antigen (HBeAg) status and flares of hepatitis. RESULTS: One hundred and twenty-six women were recruited. Twenty-seven women out of 108 with postpartum bloods (25%) met our definition of a postpartum flare (ALT range 38-1654). Using univariate analysis HBeAg status, younger age, gravida and parity were associated with a flare. On multivariate analysis HBeAg positivity at baseline fell just outside of statistical significance in predicting a postpartum flare (p=0.051). CONCLUSIONS: 25% of women with chronic hepatitis B will demonstrate increased liver inflammation in the postpartum period. This is usually asymptomatic and resolves spontaneously. This is more likely if the woman is HBeAg-positive at baseline (2.56 times the risk), although flares also commonly occur in HBeAg-negative women.

The oral toll-like receptor-7 agonist GS-9620 in patients with chronic hepatitis B virus infection.

BACKGROUND & AIMS: GS-9620 is an oral agonist of toll-like receptor 7, a pattern-recognition receptor whose activation results in innate and adaptive immune stimulation. We evaluated the safety, pharmacokinetics, and pharmacodynamics of GS-9620 in patients with chronic hepatitis B. METHODS: In two double-blind, phase 1b trials of identical design, 49 treatment-naïve and 51 virologically suppressed patients were randomized 5:1 to receive GS-9620 (at doses of 0.3mg, 1mg, 2mg, 4mg) or placebo as a single dose or as two doses seven days apart. Pharmacodynamic assessment included evaluation of peripheral mRNA expression of interferon-stimulated gene 15 (ISG15), serum interferon gamma-induced protein 10 and serum interferon (IFN)-alpha. RESULTS: Overall, 74% of patients were male and 75% were HBeAg negative at baseline. No subject discontinued treatment due to adverse events. Fifty-eight percent experienced ⩾1 adverse event, all of which were mild to moderate in severity. The most common adverse event was headache. No clinically significant changes in HBsAg or HBV DNA levels were observed. Overall, a transient dose-dependent induction of peripheral ISG15 gene expression was observed peaking within 48 hours of dosing followed by return to baseline levels within seven days. Higher GS-9620 dose, HBeAg positive status, and low HBsAg level at baseline were independently associated with greater probability of ISG15 response. Most patients (88%) did not show detectable levels of serum IFN-alpha at any time point. CONCLUSIONS: Oral GS-9620 was safe, well tolerated, and associated with induction of peripheral ISG15 production in the absence of significant systemic IFN-alpha levels or related symptoms.

Targeted individual prophylaxis offers superior risk stratification for cytomegalovirus reactivation after liver transplantation.

Cytomegalovirus (CMV) can reactivate following liver transplantation. Management of patients currently considered low risk based on pretransplant serology remains contentious, with universal prophylaxis and preemptive strategies suffering from significant deficiencies. We hypothesized that a CMV-specific T cell assay performed early after transplant as part of a preemptive strategy could better stratify "low-risk" (recipient seropositive) patients. We conducted a prospective, blinded, observational study in 75 adult recipients. QuantiFERON-cytomegalovirus was performed both before and at multiple times after transplant. Low-risk patients (n = 58) were monitored as per unit protocol and treatment was commenced if CMV > 1000 copies/mL (DNAemia). Twenty patients needed antiviral treatment for other reasons and were censored (mainly for rejection or herpes simplex virus infection); 19/38 (50%) of the remaining low-risk patients developed DNAemia at mean 34.6 days after transplant. A week 2 result of <0.1 IU/mL was significantly associated with risk of subsequent DNAemia (hazard ratio [HR], 6.9; P = 0.002). The positive predictive value of 80% suggests these patients are inappropriately labeled low risk and are actually at high likelihood of CMV reactivation. A secondary cutoff of <0.2 IU/mL was associated with moderate risk (HR, 2.8; P = 0.01). In conclusion, a protocol based on a single early CMV-specific T cell based assay would offer improved risk stratification and individualization of patient management after transplant. This could offer improved drug and service utilization and potentially result in significant improvements over both currently used protocols to manage supposedly low-risk patients.

ITPA genotype protects against anemia during peginterferon and ribavirin therapy but does not influence virological response.

UNLABELLED: On-treatment anemia is associated with higher sustained virological response (SVR) rates during peginterferon plus ribavirin (RBV) therapy. Inosine triphosphatase (ITPA) variants causing ITPase deficiency have been shown to protect against RBV-induced anemia. However, ITPase activity has not been associated with SVR. To study this discrepancy, we examined the relationships between ITPase activity, on-treatment anemia, SVR, and RBV levels in hepatitis C virus genotype 1 (HCV-1) patients from the CHARIOT study. ITPA genotype (rs7270101, rs1127354) was used to define ITPase activity in 546 patients. Plasma RBV levels were measured using high-performance liquid chromatography (HPLC). Relationships between ITPase activity, on-treatment hemoglobin (Hb) levels, RBV levels, and SVR were tested using regression modeling, survival analysis, and locally weighted scatterplot smoothing (LOWESS) plot analysis. Hb decline was independently associated with SVR (P<0.0001). ITPase deficiency was present in 35%. ITPase deficiency strongly protected against Hb decline (P<0.0001), but was not associated with SVR (P=0.28). The probability of SVR increased with lower nadir Hb for both wild-type and deficient ITPase activity, but the association curve shifted to describe a parallel relationship at higher Hb levels in patients with ITPase deficiency. In a subset (n=203), we tested the hypothesis that the association between Hb decline and SVR reflected RBV levels rather than actual Hb level. RBV levels were associated with on-treatment Hb decline and SVR, but not ITPase activity. In regression models, adjustment for RBV levels attenuated the association between Hb decline and SVR. CONCLUSION: ITPase deficiency protects against RBV-induced anemia, but is not associated with SVR. Our data suggest that the relationship between Hb decline and SVR is not mechanistic, but is linked to RBV levels.

Role of toll-like receptors in liver transplantation.

Toll-like receptors (TLRs) are pathogen recognition receptors that orchestrate the innate immune response and the subsequent adaptive immune response. TLRs can be triggered by exogenous ligands expressed by invading pathogens or by the release of endogenous ligands, such as that occurring through cellular injury during the transplantation process. They are now recognized to play an important role in many facets of transplantation biology, including rejection and tolerance, ischemia/reperfusion injury (IRI), and infections after transplantation. The role of TLRs in liver transplantation is unique with respect to other organ transplants because the portal circulation is a continuous source of TLR2 and TLR4 ligands, and this influences TLR signaling pathways, which have a central role in transplantation immunity. This review provides a critical update on recent data outlining the important role of TLRs in liver transplantation, and there is a particular focus on emerging advances in our understanding of rejection and tolerance, IRI, and infections after transplantation and on the ways in which these events may influence the recurrence of diseases such as hepatitis C infection after liver transplantation.

Cyclosporine and tacrolimus have inhibitory effects on toll-like receptor signaling after liver transplantation.

Toll-like receptors (TLRs) play a key role in transplantation biology. The effect of immunosuppression on TLR function after liver transplantation is unknown. Peripheral blood mononuclear cells (PBMCs) from 113 post-liver transplant patients and 13 healthy controls were stimulated with TLR-specific ligands [lipopolysaccharide (TLR4), pan-3-cys (P3C) (TLR2), Poly (I:C) (PIC) (TLR3), R848 (TLR7/8), and CpG (TLR9)] for 24 hours. PBMCs from 5 healthy controls were also cultured with therapeutic concentrations of cyclosporine A (CYA) and tacrolimus (TAC). Cytokine production was measured with enzyme-linked immunosorbent assays and flow cytometry. PBMCs from patients on calcineurin inhibitors after liver transplantation produced less interleukin-6 (IL-6) and tumor necrosis factor α (TNFα) in response to TLR2 stimulation (IL-6: P=0.02; TNFα: P=0.01), TLR4 stimulation (IL-6: P=0.02; TNFα: P=0.01), and TLR7/8 stimulation (IL-6: P=0.02; TNFα: P=0.02), compared with healthy controls. Both CD56(bright) and CD56(dim) natural killer (NK) cells from patients on calcineurin inhibitors also produced less interferon-γ (IFNγ) with TLR7/8 stimulation compared with healthy controls (CD56(bright) : P=0.002; CD56(dim) : P=0.004). Similar findings were demonstrated in healthy PBMCs cultured with CYA (PBMCs: TLR2, IL-6: P=0.005; TLR4, IL-6: P=0.03, TNFα: P=0.03; TLR7/8, IL-6: P=0.02, TNFα: P=0.01; CD56(dim) NK cells: TLR7/8, IFNγ: P=0.03). TAC impaired TLR4-mediated IL-6 and TNFα production by PBMCs (IL-6; P = 0.02; TNFα P = 0.009). In conclusion, patients on calcineurin inhibitors had impaired inflammatory cytokine production in response to TLR2, TLR4, and TLR7/8 stimulation compared comparison with healthy controls. Importantly, TAC and CYA appear to have different effects on TLR signaling. Impaired TLR function has important repercussions for risk of infection, graft rejection, and disease recurrence after transplantation, and the different immunosuppressive profiles of CYA and TAC may guide the choice of therapy to improve disease outcomes.

Vitamin D deficiency impacts on expression of toll-like receptor-2 and cytokine profile: a pilot study.

BACKGROUND: Vitamin D is believed to play an important role outside the endocrine system in the regulation of the immune system, and in cellular proliferation and differentiation. The aim of the study was to investigate the impact of vitamin D levels on innate immunity. METHODS: Participants for this prospective, longitudinal study were recruited amongst otherwise healthy staff of a large hospital in Victoria, Australia. Those fulfilling the inclusion criteria, including a vitamin D level of <50 nmol/L, were supplemented. Using flow cytometry, expression of the innate immune receptors TLR2, TLR4 and CD86 was measured on peripheral blood mononuclear cells (PBMCs) collected prior to vitamin D treatment and then at 1 and 3 months. Additonally, PBMCs at each timepoint were stimulated with specific TLR ligands and resultant supernatants were assayed for the cytokines TNFα, IL-6, IFN-α and IP-10. RESULTS: In participants whose vitamin D level was >100 nmol/L post supplementation (n=11), TLR2 expression on PBMCs increased significantly, with no change noted in TLR4 or CD86 expression. Stimulation of vitamin D deficient samples with TLR ligands produced a number of proinflammatory cytokines, which were significantly reduced upon vitamin D normalisation. In patients whose levels returned to a deficient level at 3 months despite ongoing low-level supplementation, an increase in the pro-inflamamtory state returned. This suggests that vitamin D may play an important role in ensuring an appropriate baseline pro-inflammatory state. CONCLUSIONS: This ex-vivo pilot study adds clinical evidence supporting a possibly important role for vitamin D in innate immunity. If confirmed, this unique clinical study has potentially significant implications for the treatment of a variety of inflammatory conditions, where achieving optimal vitamin D levels may help reduce inflammation.