SARS-CoV-2 humoral immunity in people living with HIV-1.

The effect of COVID-19 on the high number of immunocompromised people living with HIV-1 (PLWH), particularly in Africa, remains a critical concern. Here, we identify key areas that still require further investigation, by examining COVID-19 vaccine effectiveness, and understanding antibody responses in SARS-CoV-2 infection and vaccination in comparison with people without HIV-1 (PWOH). We also assess the potential impact of pre-existing immunity against endemic human coronaviruses on SARS-CoV-2 responses in these individuals. Lastly, we discuss the consequences of persistent infection in PLWH (or other immunocompromised individuals), including prolonged shedding, increased viral diversity within the host, and the implications on SARS-CoV-2 evolution in Africa.

Development of LIBRA-seq for the guinea pig model system as a tool for the evaluation of antibody responses to multivalent HIV-1 vaccines.

Consistent elicitation of serum antibody responses that neutralize diverse clades of HIV-1 remains a primary goal of HIV-1 vaccine research. Prior work has defined key features of soluble HIV-1 Envelope (Env) immunogen cocktails that influence the neutralization breadth and potency of multivalent vaccine-elicited antibody responses including the number of Env strains in the regimen. We designed immunization groups that consisted of different numbers of SOSIP Env strains to be used in a cocktail immunization strategy: the smallest cocktail (group 2) consisted of a set of two Env strains, which were a subset of the three Env strains that made up group 3, which, in turn, were a subset of the six Env strains that made up group 4. Serum neutralizing titers were modestly broader in guinea pigs that were immunized with a cocktail of three Envs compared to cocktails of two and six, suggesting that multivalent Env immunization could provide a benefit but may be detrimental when the cocktail size is too large. We then adapted the LIBRA-seq platform for antibody discovery to be compatible with guinea pigs, and isolated several tier 2 neutralizing monoclonal antibodies. Three antibodies isolated from two separate guinea pigs were similar in their gene usage and CDR3s, establishing evidence for a guinea pig public clonotype elicited through vaccination. Taken together, this work investigated multivalent HIV-1 Env immunization strategies and provides a novel methodology for screening guinea pig B cell receptor antigen specificity at a high-throughput level using LIBRA-seq.IMPORTANCEMultivalent vaccination with soluble Env immunogens is at the forefront of HIV-1 vaccination strategies but little is known about the influence of the number of Env strains included in vaccine cocktails. Our results suggest that adding more strains is sometimes beneficial but may be detrimental when the number of strains is too high. In addition, we adapted the LIBRA-seq platform to be compatible with guinea pig samples and isolated several tier 2 neutralizing monoclonal antibodies, some of which share V and J gene usage and >70% CDR3 identity, thus establishing the existence of public clonotypes in guinea pigs elicited through vaccination.

SARS-CoV-2 BA.4/5 infection triggers more cross-reactive FcγRIIIa signaling and neutralization than BA.1, in the context of hybrid immunity.

SARS-CoV-2 variants of concern (VOCs) differentially trigger neutralizing and antibody-dependent cellular cytotoxic (ADCC) antibodies with variable cross-reactivity. Omicron BA.4/5 was approved for inclusion in bivalent vaccination boosters, and therefore the antigenic profile of antibodies elicited by this variant is critical to understand. Here, we investigate the ability of BA.4/5-elicited antibodies following the first documented (primary) infection (n = 13) or breakthrough infection after vaccination (n = 9) to mediate neutralization and FcγRIIIa signaling across multiple SARS-CoV-2 variants including XBB.1.5 and BQ.1. Using a pseudovirus neutralization assay and a FcγRIIIa crosslinking assay to measure ADCC potential, we show that unlike SARS-CoV-2 Omicron BA.1, BA.4/5 infection triggers highly cross-reactive functional antibodies. Cross-reactivity was observed both in the absence of prior vaccination and in breakthrough infections following vaccination. However, BQ.1 and XBB.1.5 neutralization and FcγRIIIa signaling were significantly compromised compared to other VOCs, regardless of prior vaccination status. BA.4/5 triggered FcγRIIIa signaling was significantly more resilient against VOCs (<10-fold decrease in magnitude) compared to neutralization (10- to 100-fold decrease). Overall, this study shows that BA.4/5 triggered antibodies are highly cross-reactive compared to those triggered by other variants. Although this is consistent with enhanced neutralization and FcγRIIIa signaling breadth of BA.4/5 vaccine boosters, the reduced activity against XBB.1.5 supports the need to update vaccines with XBB sublineage immunogens to provide adequate coverage of these highly antibody evasive variants. IMPORTANCE: The continued evolution of SARS-CoV-2 has resulted in a number of variants of concern. Of these, the Omicron sublineage is the most immune evasive. Within Omicron, the BA.4/5 sublineage drove the fifth wave of infection in South Africa prior to becoming the dominant variant globally. As a result this spike sequence was approved as part of a bivalent vaccine booster, and rolled out worldwide. We aimed to understand the cross-reactivity of neutralizing and Fc mediated cytotoxic functions elicited by BA.4/5 infection following infection or breakthrough infection. We find that, in contrast to BA.1 which triggered fairly strain-specific antibodies, BA.4/5 triggered antibodies that are highly cross-reactive for neutralization and antibody-dependent cellular cytotoxicity potential. Despite this cross-reactivity, these antibodies are compromised against highly resistant variants such as XBB.1.5 and BQ.1. This suggests that next-generation vaccines will require XBB sublineage immunogens in order to protect against these evasive variants.

Homologous Ad26.COV2.S vaccination results in reduced boosting of humoral responses in hybrid immunity, but elicits antibodies of similar magnitude regardless of prior infection.

The impact of previous SARS-CoV-2 infection on the durability of Ad26.COV2.S vaccine-elicited responses, and the effect of homologous boosting has not been well explored. We followed a cohort of healthcare workers for 6 months after receiving the Ad26.COV2.S vaccine and a further one month after they received an Ad26.COV2.S booster dose. We assessed longitudinal spike-specific antibody and T cell responses in individuals who had never had SARS-CoV-2 infection, compared to those who were infected with either the D614G or Beta variants prior to vaccination. Antibody and T cell responses elicited by the primary dose were durable against several variants of concern over the 6 month follow-up period, regardless of infection history. However, at 6 months after first vaccination, antibody binding, neutralization and ADCC were as much as 59-fold higher in individuals with hybrid immunity compared to those with no prior infection. Antibody cross-reactivity profiles of the previously infected groups were similar at 6 months, unlike at earlier time points, suggesting that the effect of immune imprinting diminishes by 6 months. Importantly, an Ad26.COV2.S booster dose increased the magnitude of the antibody response in individuals with no prior infection to similar levels as those with previous infection. The magnitude of spike T cell responses and proportion of T cell responders remained stable after homologous boosting, concomitant with a significant increase in long-lived early differentiated CD4 memory T cells. Thus, these data highlight that multiple antigen exposures, whether through infection and vaccination or vaccination alone, result in similar boosts after Ad26.COV2.S vaccination.

Hemagglutinin stalk-specific Fc-mediated functions are associated with protection against influenza-illness after seasonal influenza vaccination in pregnant women.

BACKGROUND: Several influenza vaccine candidates aim to elicit antibodies against the conserved hemagglutinin stalk domain. Understanding the protective mechanism of these antibodies, which mediate broad neutralization and Fc-mediated functions, following seasonal vaccination is critical. METHODS: Plasma samples were obtained from a subset of pregnant women living with or without HIV-1 enrolled in a randomised trial (138 trivalent inactivated vaccine [TIV] and 145 placebo recipients). Twenty-three influenza-illness cases were confirmed within 6 months postpartum. We measured H1 stalk-specific antibody-dependent cellular phagocytosis (ADCP), complement deposition (ADCD) and cellular cytotoxicity (ADCC) at enrolment and 1-month post-vaccination. The association between these Fc-mediated functions and protection against influenza-illness following vaccination was examined using multiple logistic regression analysis and risk reduction thresholds were defined by the score associated with the lowest odds of influenza-illness. RESULTS: Amongst TIV and placebo recipients, lower H1 stalk-specific ADCP and ADCD activity was detected for participants with confirmed influenza compared with individuals without confirmed influenza-illness 1-month post-vaccination. Pre-existing ADCP scores ≥250 reduced the odds of A/H1N1 infection (odds ratio 0.11; p=0.01) with an 83% likelihood of risk reduction. Following TIV, ADCD scores of ≥25 and ≥15 significantly reduced the odds against A/H1N1 (0.10; p=0.01) and non-group 1 (0.06; p=0.0004) influenza virus infections, respectively. These ADCD scores were associated with >84% likelihood of risk reduction. H1 stalk-specific ADCC potential was not associated with protection against influenza-illness. CONCLUSION: H1 stalk-specific ADCD correlates with protection against influenza-illness following influenza vaccination during pregnancy. These findings provide insight into the protective mechanisms of HA stalk antibodies.

Comparing the immune abnormalities in MIS-C to healthy children and those with inflammatory disease reveals distinct inflammatory cytokine production and a monofunctional T cell response.

Multisystem inflammatory syndrome in children (MIS-C) is a severe, hyperinflammatory disease that occurs after exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The underlying immune pathology of MIS-C is incompletely understood, with limited data comparing MIS-C to clinically similar paediatric febrile diseases at presentation. SARS-CoV-2-specific T cell responses have not been compared in these groups to assess whether there is a T cell profile unique to MIS-C. In this study, we measured inflammatory cytokine concentration and SARS-CoV-2-specific humoral immunity and T cell responses in children with fever and suspected MIS-C at presentation (n = 83) where MIS-C was ultimately confirmed (n = 58) or another diagnosis was made (n = 25) and healthy children (n = 91). Children with confirmed MIS-C exhibited distinctly elevated serum IL-10, IL-6, and CRP at presentation. No differences were detected in SARS-CoV-2 spike IgG serum concentration, neutralisation capacity, antibody dependant cellular phagocytosis, antibody dependant cellular cytotoxicity or SARS-CoV-2-specific T cell frequency between the groups. Healthy SARS-CoV-2 seropositive children had a higher proportion of polyfunctional SARS-CoV-2-specific CD4+ T cells compared to children with MIS-C and those with other inflammatory or infectious diagnoses, who both presented a largely monofunctional SARS-CoV-2-specific CD4+ T cell profile. Treatment with steroids and/or intravenous immunoglobulins resulted in rapid reduction of inflammatory cytokines but did not affect the SARS-CoV-2-specific IgG or CD4+ T cell responses in MIS-C. In these data, MIS-C had a unique cytokine profile but not a unique SARS-CoV-2 specific humoral or T cell cytokine response.

Efficacy and safety of ramucirumab plus carboplatin and paclitaxel in untreated metastatic thymic carcinoma: RELEVENT phase II trial (NCT03921671).

BACKGROUND: Thymic carcinoma (TC) is a rare tumor with aggressive behavior. Chemotherapy with carboplatin plus paclitaxel represents the treatment of choice for advanced disease. Antiangiogenic drugs, including ramucirumab, have shown activity in previously treated patients. RELEVENT trial was designed to evaluate the activity and safety of ramucirumab plus chemotherapy as first-line treatment in advanced TC. PATIENTS AND METHODS: This phase II trial was conducted within the Italian TYME network. Eligible patients had treatment naive advanced TC. They received ramucirumab, carboplatin and paclitaxel for 6 cycles, followed by ramucirumab maintenance until disease progression or intolerable toxicity. Primary endpoint was ORR according to RECIST v1.1 as assessed by the investigator. Secondary endpoints were PFS, OS and safety. Centralized radiologic review was performed. RESULTS: From 11/2018 to 06/2023, 52 patients were screened, 35 were enrolled. Median age was 60.8 years, 71.4% of patients were male and 85.7% had Masaoka-Koga stage IVB. ECOG PS was 0 in 68.5%, 1 in 31.4% patients. At the present analysis carried out some months later the interim analysis (earlier than expected) on 35 patients, ORR was 80.0% [95%CI 63.1-91.6]. At the centralized radiological review of 33/35 evaluable patients, ORR was 57.6% [95%CI 39.2-74.5]. After a median follow-up of 31.6 months, median PFS was 18.1 [95%CI 10.8-52.3] and median OS 43.8 [95%CI 31.9-NR] months. Thirty-two out of 35 patients (91.4%) experienced at least one treatment-related adverse event (AE), of which 48.6% were AE≥G3. CONCLUSIONS: In previously untreated advanced TC, the addition of ramucirumab to carboplatin and paclitaxel showed the highest activity compared to historical controls, with a manageable safety profile. Despite the small number of patients, given the rarity of the disease, the trial results support the consideration of this combination as first-line treatment in TC.

Incidence, epidemiology, and outcomes of acute allograft rejection following liver transplantation in Australia.

Acute allograft rejection is a well-known complication of liver transplantation (LT). The incidence, epidemiology, and outcomes of acute rejection have not been well described in Australia. We retrospectively studied consecutive adults who underwent deceased donor LT at a single center between 2010 and 2020. Donor and recipient data at the time of LT and recipient outcomes were collected from a prospective LT database. Liver biopsy reports were reviewed, and only a graft's first instance of biopsy-proven acute rejection was analyzed. During the study period, 796 liver transplants were performed in 770 patients. Biopsy-proven rejection occurred in 34.9% of transplants. There were no significant changes in the incidence of rejection over time (linear trend p =0.11). The median time to the first episode of rejection was 71 days after LT: 2.2% hyperacute, 50.4% early (≤90 d), and 47.5% late rejection (>90 d). Independent risk factors for rejection were younger recipient age at transplant (aHR 0.98 per year increase, 95% CI: 0.97-1.00, p =0.01), and ABO-incompatible grafts (aHR 2.55 vs. ABO-compatible, 95% CI: 1.27-5.09, p <0.01) while simultaneous multiorgan transplants were protective (aHR 0.21 vs. LT only, 95% CI: 0.08-0.58, p <0.01). Development of acute rejection (both early and late) was independently associated with significantly reduced graft (aHR 3.13, 95% CI: 2.21-4.42, p <0.001) and patient survival (aHR 3.42, 95% CI: 2.35-4.98, p <0.001). In this 11-year Australian study, acute LT rejection occurred in 35%, with independent risk factors of younger recipient age and ABO-incompatible transplant, while having a simultaneous multiorgan transplant was protective. Acute rejection was independently associated with reduced graft and patient survival after adjustment for other factors.

Recommendations on the Use of Multiple Labels in Human Mass Balance Studies.

The administration of radiolabeled drug candidates is considered the gold standard in absorption, distribution, metabolism, and excretion studies for small-molecule drugs since it allows facile and accurate quantification of parent drug, metabolites, and total drug-related material independent of the compound structure. The choice of the position of the radiolabel, typically 14C or 3H, is critical to obtain relevant information. Sometimes, a biotransformation reaction may lead to cleavage of a part of the molecule. As a result, only the radiolabeled portion can be followed, and information on the fate of the nonlabeled metabolite may be lost. Synthesis and administration of two or more radiolabeled versions of the parent drug as a mixture or in separate studies may resolve this issue but comes with additional challenges. In this paper, we address the questions that may be considered to help make the right choice whether to use a single or multiple radiolabel approach and discuss the pros and cons of different multiple-labeling strategies that can be taken as well as alternative methods that allow the nonlabeled part of the molecule to be followed. SIGNIFICANCE STATEMENT: Radiolabeled studies are the gold standard in drug metabolism research, but molecules can undergo cleavage with loss of the label. This often results in discussions around potential use of multiple labels, which seem to be occurring with increased frequency since an increasing proportion of the small-molecule drugs are tending towards larger molecular weights. This review provides insight and decision criteria in considering a multiple-label approach as well as pros and cons of different strategies that can be followed.

Impact of Share 35 liver transplantation allocation in Australia and New Zealand.

Patients with high model for end-stage liver disease (MELD) scores waiting for liver transplantation in Australia and New Zealand (ANZ) have had limited access to deceased donor livers and therefore binational sharing of livers, for patients with a MELD score ≥35 was introduced in February 2016. Waiting list mortality, post-transplant outcomes and intention-to-treat survival were compared between patients whose MELD score reached 35 on the waiting list between October 2013 and April 2015 (Pre-Share 35 group, n = 23) and patients who were Share 35 listed between February 2016 and May 2022 (Share 35 group, n = 112). There was significantly reduced waiting list mortality in share 35 listed patients in comparison to the pre-Share 35 group (11.7% vs. 52.2%, OR .120 95% CI .044-.328, P < .001). Post-transplant patient and graft survival were not significantly different between the groups (5-year patient survival 82% vs. 84%, P = .991, 5-year graft survival 82% vs. 76%, P = .543). Intention-to-treat survival was superior in the Share 35 group (HR .302, 95% CI .149-.614, P < .001). Introduction of Share 35 in ANZ resulted in a 78% risk reduction in waiting list mortality, equivalent post-transplant survival and an improvement in intention-to-treat survival.

Low rate of surgical site infections after liver transplantation: A 5-year retrospective cohort study.

BACKGROUND: Surgical site infection (SSI) after liver transplant (LT) is common, but no studies have been conducted in Australia. The purpose of this study was to determine the proportion of patients who developed an SSI post-LT in Australia's largest LT unit. METHODS: This was a single-center retrospective cohort study. We included all LT recipients who were aged 18 years or more and received their transplant between March 1, 2018 and April 1, 2023. The primary outcome was to determine the proportion of LT recipients who developed an SSI within 30 days of transplantation. RESULTS: There were 404 LTs performed during the study period, and 375 met inclusion criteria. Of these, 8% (n = 31/375) developed an SSI and were classified as superficial (3%, n = 12/375) or deep/organ space (5%, n = 19/375). The most common antibiotics used for prophylaxis were amoxicillin/clavulanate (75%, n = 281/375), followed by piperacillin/tazobactam (17%, n = 62/375). Independent risk factors associated with the development of SSI were Roux-en-Y hepaticojejunostomy (aOR 3.16, 95% CI 1.17-8.28, p = .02), operative time (per 60-min increment) (aOR 1.23, 95% CI 1.02-1.48), and re-operation (aOR 4.16, 95% CI 1.81-9.58, p < .01). Type of antibiotic received perioperatively was not significantly associated with SSI. CONCLUSION: SSI occurred in 8% of LT recipients and was predominantly related to operation-related factors rather than patient- or antibiotic-related factors.

Broadening and strengthening the health providers caring for patients with chronic hepatitis C may improve continuity of care.

BACKGROUND: Direct-acting antiviral (DAA) therapies for hepatitis C virus infection (HCV) lead to excellent rates of sustained virological response (SVR). However, loss to follow-up (LTFU) for SVR testing remains a challenge. We examine factors associated with LTFU in a real-world setting. METHODS: Adults who received DAA therapy for HCV in one of 26 centers across Australia during 2016-2021 were followed up for 2 years. Data sources included the patient medical records and the national Pharmaceutical and Medicare Benefits Schemes. Linkage to Medicare provided utilization data of other health-care providers and re-treatment with DAAs. LTFU was defined as no clinic attendance for SVR testing by at least 52 weeks after DAA treatment commencement. Multivariable logistic regression assessed factors associated with LTFU. RESULTS: In 3619 patients included in the study (mean age 52.0 years; SD = 10.5), 33.6% had cirrhosis (69.4% Child-Pugh class B/C), and 19.3% had HCV treatment prior to the DAA era. Five hundred and fifteen patients (14.2%) were LTFU. HCV treatment initiation in 2017 or later (adj-OR = 2.82, 95% confidence interval [CI] 2.25-3.54), younger age (adj-OR = 2.63, 95% CI 1.80-3.84), Indigenous identification (adj-OR = 1.99, 95% CI 1.23-3.21), current injection drug use or opioid replacement therapy (adj-OR = 1.66, 95% CI 1.25-2.20), depression treatment (adj-OR = 1.49, 95% CI 1.17-1.90), and male gender (adj-OR = 1.31, 95% CI 1.04-1.66) were associated with LTFU. CONCLUSIONS: These findings stress the importance of strengthening the network of providers caring for patients with HCV. In particular, services targeting vulnerable groups of patients such as First Nations Peoples, youth health, and those with addiction and mental health disorders should be equipped to treat HCV.

Functional consequences of allotypic polymorphisms in human immunoglobulin G subclasses.

Heritable polymorphisms within the human IgG locus, collectively termed allotypes, have often been linked by statistical associations, but rarely mechanistically, to a wide range of disease states. One potential explanation for these associations is that IgG allotype alters host cell receptors' affinity for IgG, dampening or enhancing an immune response depending on the nature of the change and the receptors. In this work, a panel of allotypic antibody variants were evaluated using multiplexed, label-free biophysical methods and cell-based functional assays to determine what effect, if any, human IgG polymorphisms have on antibody function. While we observed several differences in FcγR affinity among allotypes, there was little evidence of dramatically altered FcγR-based effector function or antigen recognition activity associated with this aspect of genetic variability.

Shared N417-Dependent Epitope on the SARS-CoV-2 Omicron, Beta, and Delta Plus Variants.

As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to evolve, several variants of concern (VOCs) have arisen which are defined by multiple mutations in their spike proteins. These VOCs have shown variable escape from antibody responses and have been shown to trigger qualitatively different antibody responses during infection. By studying plasma from individuals infected with either the original D614G, Beta, or Delta variants, we showed that the Beta and Delta variants elicit antibody responses that are overall more cross-reactive than those triggered by D614G. Patterns of cross-reactivity varied, and the Beta and Delta variants did not elicit cross-reactive responses to each other. However, Beta-elicited plasma was highly cross-reactive against Delta Plus (Delta+), which differs from Delta by a single K417N mutation in the receptor binding domain, suggesting that the plasma response targets the N417 residue. To probe this further, we isolated monoclonal antibodies from a Beta-infected individual with plasma responses against Beta, Delta+, and Omicron, which all possess the N417 residue. We isolated an N417-dependent antibody, 084-7D, which showed similar neutralization breadth to the plasma. The 084-7D MAb utilized the IGHV3-23*01 germ line gene and had somatic hypermutations similar to those of previously described public antibodies which target the 417 residue. Thus, we have identified a novel antibody which targets a shared epitope found on three distinct VOCs, enabling their cross-neutralization. Understanding antibodies targeting escape mutations, such as K417N, which repeatedly emerge through convergent evolution in SARS-CoV-2 variants, may aid in the development of next-generation antibody therapeutics and vaccines. IMPORTANCE The evolution of SARS-CoV-2 has resulted in variants of concern (VOCs) with distinct spike mutations conferring various immune escape profiles. These variable mutations also influence the cross-reactivity of the antibody response mounted by individuals infected with each of these variants. This study sought to understand the antibody responses elicited by different SARS-CoV-2 variants and to define shared epitopes. We show that Beta and Delta infections resulted in antibody responses that were more cross-reactive than the original D614G variant, but they had differing patterns of cross-reactivity. We further isolated an antibody from Beta infection which targeted the N417 site, enabling cross-neutralization of Beta, Delta+, and Omicron, all of which possess this residue. The discovery of antibodies which target escape mutations common to multiple variants highlights conserved epitopes to target in future vaccines and therapeutics.

Epidemiology, characteristics, and outcomes of patients with acute-on-chronic liver failure in Australia.

BACKGROUND AND AIM: Acute-on-chronic liver failure (ACLF) is distinct from acute decompensation (AD) of cirrhosis in its clinical presentation, pathophysiology, and prognosis. There are limited published Australian ACLF data. METHODS: We performed a single-center retrospective cohort study of all adults with cirrhosis admitted with a decompensating event to a liver transplantation (LT) centre between 2015 and 2020. ACLF was defined using the European Association for the Study of the Liver-Chronic Liver Failure (EASL-CLIF) definition while those who did not meet the definition were classified as AD. The primary outcome of interest was 90-day LT-free survival. RESULTS: A total of 615 patients had 1039 admissions for a decompensating event. On their index admission, 34% (209/615) of patients were classified as ACLF. Median admission model for end-stage liver disease (MELD) and MELD-Na scores were higher in ACLF patients compared with AD (21 vs 17 and 25 vs 20 respectively, both P < 0.001). Both the presence and severity of ACLF (grade ≥ 2) significantly predicted worse LT-free survival compared with patients with AD. The EASL-CLIF ACLF score (CLIF-C ACLF), MELD and MELD-Na scores performed similarly in predicting 90-day mortality. Patients with index ACLF had a higher risk of 28-day mortality (28.1% vs 5.1%, P < 0.001) and shorter times to readmission compared with those with AD. CONCLUSION: ACLF complicates over a third of hospital admissions for cirrhosis with decompensating events and is associated with a high short-term mortality. The presence and grade of ACLF predicts 90-day mortality and should be identified as those at greatest risk of poor outcome without intervention such as LT.

Liver Disease and Poor Adherence Limit Hepatitis C Cure: A Real-World Australian Treatment Cohort.

BACKGROUND AND AIMS: In 2016, direct-acting antiviral (DAA) treatment for hepatitis C (HCV) became available through Australia's universal health care system, with the aim of HCV elimination. We report real-world effectiveness of DAA HCV treatment in Australia from a clinically well-informed cohort, enriched for cirrhosis and prior HCV treatment. METHODS: 3413 patients were recruited from 26 hospital liver clinics across Australia from February 2016 to June 2020. Clinical history and sustained viral response (SVR) were obtained from medical records and data linkage to the Australian Pharmaceutical Benefits Scheme. Factors associated with SVR were assessed by multivariable logistic regression (MVR). RESULTS: At recruitment, 32.2% had cirrhosis (72.9% Child Pugh class B/C), and 19.9% were treatment experienced. Of the 2,939 with data, 93.3% confirmed SVR. 137 patients received second-line therapy. Patients with cirrhosis had lower SVR rate (88.4 vs. 95.8%; p < 0.001). On MVR, failure to achieve SVR was associated with Genotype 3 (adj-OR = 0.42, 95%CI 0.29-0.61), male gender (adj-OR = 0.49, 95%CI 0.31-0.77), fair/poor adherence (adj-OR = 0.52, 95%CI 0.28-0.94), cirrhosis (adj-OR = 0.57, 95%CI 0.36-0.88), FIB-4 > 3.25 (adj-OR = 0.52, 95%CI 0.33-0.83) and MELD score ≥ 20 (adj-OR = 0.25, 95%CI 0.08-0.80). Consistent results were seen in cirrhotic sub-analysis. CONCLUSIONS: Excellent SVR rates were achieved with DAAs in this real-world cohort of patients with chronic HCV infection. More advanced liver disease and clinician impression of poor adherence were associated with HCV treatment failure. Supports to improve liver fibrosis assessment skills for non-specialist DAA prescribers in the community and to optimize patient adherence are likely to enable more effective pursuit of HCV elimination in Australia.

Biofunctionality with a twist: the importance of molecular organisation, handedness and configuration in synthetic biomaterial design.

The building blocks of life - nucleotides, amino acids and saccharides - give rise to a large variety of components and make up the hierarchical structures found in Nature. Driven by chirality and non-covalent interactions, helical and highly organised structures are formed and the way in which they fold correlates with specific recognition and hence function. A great amount of effort is being put into mimicking these highly specialised biosystems as biomaterials for biomedical applications, ranging from drug discovery to regenerative medicine. However, as well as lacking the complexity found in Nature, their bio-activity is sometimes low and hierarchical ordering is missing or underdeveloped. Moreover, small differences in folding in natural biomolecules (e.g., caused by mutations) can have a catastrophic effect on the function they perform. In order to develop biomaterials that are more efficient in interacting with biomolecules, such as proteins, DNA and cells, we speculate that incorporating order and handedness into biomaterial design is necessary. In this review, we first focus on order and handedness found in Nature in peptides, nucleotides and saccharides, followed by selected examples of synthetic biomimetic systems based on these components that aim to capture some aspects of these ordered features. Computational simulations are very helpful in predicting atomic orientation and molecular organisation, and can provide invaluable information on how to further improve on biomaterial designs. In the last part of the review, a critical perspective is provided along with considerations that can be implemented in next-generation biomaterial designs.

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.

Combination treatments including the small-interfering RNA JNJ-3989 induce rapid and sometimes prolonged viral responses in patients with CHB.

BACKGROUND & AIMS: RNA interference therapy has been shown to reduce hepatitis B surface antigen (HBsAg) levels in preclinical models, which could confer functional cure in patients with chronic hepatitis B. This phase IIa trial (ClinicalTrials.gov Identifier: NCT03365947) assessed the safety and efficacy of the small-interfering RNA JNJ-73763989 (JNJ-3989) plus a nucleos(t)ide analogue (NA), with/without the capsid assembly modulator JNJ-56136379 (JNJ-6379) in patients with chronic hepatitis B. METHODS: Treatment-naïve and NA-suppressed patients received 3 subcutaneous JNJ-3989 doses every week (QW; 100, 200, or 300 mg), 2 weeks (Q2W; 100 mg) or 4 weeks (Q4W; 25, 50, 100, 200, 300, or 400 mg), or JNJ-3989 Q4W (200 mg) plus oral JNJ-6379 250 mg daily for 12 weeks. Patients received NAs throughout. RESULTS: Eighty-four patients were recruited. All treatments were well tolerated, with all 5 serious adverse events considered unrelated to study drugs. JNJ-3989 100 to 400 mg Q4W resulted in HBsAg reductions ≥1 log10 IU/ml from baseline in 39/40 (97.5%) patients at the nadir. All patients receiving the triple combination (n = 12) had HBsAg reductions ≥1 log10 IU/ml from baseline at the nadir. HBsAg reductions were similar for HBeAg-positive (n = 21) and HBeAg-negative (n = 47) patients in all JNJ-3989 Q4W treatment arms, including the triple combination (n = 68). Smaller HBsAg reductions were seen with 25 mg (n = 8) and 50 mg (n = 8) than with 100 to 400 mg (n = 40). Shorter dosing intervals (QW [n = 12] and Q2W [n = 4]) did not improve response vs. Q4W dosing. HBsAg reductions ≥1 log10 IU/ml from baseline persisted in 38% of patients 336 days after the last JNJ-3989 dose. CONCLUSIONS: JNJ-3989 plus an NA, with/without JNJ-6379, was well tolerated and resulted in HBsAg reductions up to 336 days after the last JNJ-3989 Q4W dose. CLINICAL TRIAL NUMBER: NCT03365947. LAY SUMMARY: Hepatitis B virus affects people's livers and produces particles called hepatitis B surface antigen (HBsAg) that damage a person's liver and can help the virus infect a person for a long time, known as chronic hepatitis B (CHB). In this study, a new treatment called JNJ-3989 was assessed (in combination with normal treatment known as nucleos(t)ide analogues), for its safety and effectiveness in reducing the number of HBsAg particles in people with CHB. The results of this study showed that treatment with JNJ-3989 could be safe for people with CHB, lowered their HBsAg levels, and kept HBsAg levels lowered for 336 days in 38% of patients after receiving their last dose of JNJ-3989.

Turning the Tide on Hepatitis C Virus-Related Liver Transplantation: The Return on Investment in Hepatitis C Virus Treatment in Australia and New Zealand.

Introduction of universal access to direct-acting antiviral (DAA) therapy for hepatitis C virus (HCV) in Australia and New Zealand on March 1st , 2016, has had a major impact on the number of people with chronic HCV infection, but the impact on liver transplantation rates is unknown. We conducted a retrospective registry study including all adult liver transplantations from the Australia and New Zealand Liver and Intestinal Liver Transplant Registry (ANZLITR) data set. Interrupted time series analysis determined the impact of DAAs in 2016 on the number of HCV liver transplantations per year. Cox regression analysis was used to determine the impact of DAAs on post-liver transplantation survival. Between January 1, 1990, and December 31, 2019 5318 adult liver transplantations were performed, and 29% (1531) were for HCV infection. Prior to the introduction of DAAs, there was a mean increase of 3.5 adult liver transplantations performed for HCV per annum, but between 2016 and 2019 there was a mean decrease of 7.9 adult liver transplantations per annum (P < 0.001). Similarly, the proportion of liver transplantations performed for HCV increased from 9% (1990) to 33% in 2016 and then fell to 23% in 2019 (P < 0.001). The number and proportion of patients with HCV added to the liver transplantation waiting list also fell in 2016 (P < 0.001) when compared with other indications. The introduction of DAAs was associated with a 31% reduction in death after liver transplantation, adjusted for age at transplant and hepatocellular carcinoma (HCC; hazard ratio [HR], 0.69; 95% confidence interval [CI], 0.48-0.99; P = 0.047). The number of adult liver transplantations performed for HCV-related liver cirrhosis and HCC has reduced since the introduction of universal access to DAAs in 2016 in Australia and New Zealand.