Non-invasive diagnosis and follow-up of chronic infection with hepatitis B virus

Diagnosis of chronic hepatitis B virus (HBV) infection, initial staging of infection and monitoring of treated and untreated patients are mainly based on clinical, biological and imaging criteria allowing a complete non-invasive management for the majority of patients. Along to the conventional virological tools, rapid diagnostic tests and blotting paper tests for HBV DNA are validated alternatives. After diagnosis, the initial work-up should include HIV, HCV and HDV serologies, HBeAg status, and HBsAg and HBV DNA quantification. Assessment of severity (inflammation and fibrosis) is based on ALT serum levels and non-invasive evaluation of liver fibrosis by elastography or blood tests, which must be interpreted cautiously using specific cut-offs and taking into account ALT levels. Taken together, these parameters allow disease classification and treatment decision. Decision of hepatocellular carcinoma screening by ultra-sound every six months may be difficult in non-cirrhotic patients and the use of risk-scores such as PAGE-B is encouraged. Chronic HBV infection often has a dynamic and often unpredictable profile and regular monitoring is mandatory. In untreated patients, regular (3-12 months) follow-up should include ALT and HBV DNA serum levels. Periodical HBsAg quantification and non-invasive evaluation of liver fibrosis may refine disease outcome and prognosis. In treated patients, checking efficacy is mainly based on HBV DNA negativity. In patients with advanced fibrosis, evolution of liver stiffness can be useful for portal hypertension evaluation, but its improvement should not be considered to stop hepatocellular carcinoma screening. Finally, new parameters (HBV RNA, HBcrAg) are promising but their use is still restricted for research.

Heater-Associated Erythema Ab Igne: Case Report and Review of Thermal-Related Skin Conditions

Erythema ab igne is a thermal-associated skin condition that can occur secondary to persistent direct or indirect contact with heat. Historically, erythema ab igne has been linked to fireplace and stove exposures; more recently, it has been associated with heaters, hot water bottles, and laptops. A 48-year-old woman presented for the evaluation of hyperpigmented, reticulated macular lesions on her distal legs. Additional history revealed that she had developed erythema ab igne secondary to the use of a space heater underneath her desk at work. Her skin condition stopped progressing with removal of the causative agent. In addition to erythema ab igne, heat-related skin conditions include basal cell carcinomas and squamous cell carcinomas, burns, erythromelalgia, subtypes of urticaria, and ultraviolet-associated disorders. Awareness of thermal-associated skin conditions enables the clinician to establish the appropriate diagnosis based on the associated history of the condition, the morphology of the skin lesion, and, if necessary, correlation with the skin biopsy findings of the cutaneous condition.

Effects and cost of different strategies to eliminate hepatitis C virus transmission in Pakistan: a modelling analysis

BACKGROUND

The WHO elimination strategy for hepatitis C virus advocates scaling up screening and treatment to reduce global hepatitis C incidence by 80% by 2030, but little is known about how this reduction could be achieved and the costs of doing so. We aimed to evaluate the effects and cost of different strategies to scale up screening and treatment of hepatitis C in Pakistan and determine what is required to meet WHO elimination targets for incidence.

METHODS

We adapted a previous model of hepatitis C virus transmission, treatment, and disease progression for Pakistan, calibrating using available data to incorporate a detailed cascade of care for hepatitis C with cost data on diagnostics and hepatitis C treatment. We modelled the effect on various outcomes and costs of alternative scenarios for scaling up screening and hepatitis C treatment in 2018-30. We calibrated the model to country-level demographic data for 1960-2015 (including population growth) and to hepatitis C seroprevalence data from a national survey in 2007-08, surveys among people who inject drugs (PWID), and hepatitis C seroprevalence trends among blood donors. The cascade of care in our model begins with diagnosis of hepatitis C infection through antibody screening and RNA confirmation. Diagnosed individuals are then referred to care and started on treatment, which can result in a sustained virological response (effective cure). We report the median and 95% uncertainty interval (UI) from 1151 modelled runs.

FINDINGS

One-time screening of 90% of the 2018 population by 2030, with 80% referral to treatment, was projected to lead to 13·8 million (95% UI 13·4-14·1) individuals being screened and 350 000 (315 000-385 000) treatments started annually, decreasing hepatitis C incidence by 26·5% (22·5-30·7) over 2018-30. Prioritised screening of high prevalence groups (PWID and adults aged ≥30 years) and rescreening (annually for PWID, otherwise every 10 years) are likely to increase the number screened and treated by 46·8% and decrease incidence by 50·8% (95% UI 46·1-55·0). Decreasing hepatitis C incidence by 80% is estimated to require a doubling of the primary screening rate, increasing referral to 90%, rescreening the general population every 5 years, and re-engaging those lost to follow-up every 5 years. This approach could cost US$8·1 billion, reducing to $3·9 billion with lowest costs for diagnostic tests and drugs, including health-care savings, and implementing a simplified treatment algorithm.

INTERPRETATION

Pakistan will need to invest about 9·0% of its yearly health expenditure to enable sufficient scale up in screening and treatment to achieve the WHO hepatitis C elimination target of an 80% reduction in incidence by 2030.

FUNDING

UNITAID.

Characterization and management of asymptomatic Mycobacterium infections at the Zebrafish International Resource Center

The Zebrafish International Resource Center (ZIRC) supplies wildtype, mutant, and transgenic zebrafish (Danio rerio) to the international research community. In 2005, the ZIRC halted shipment of adult Tübingen (TU) zebrafish, a popular wildtype line, after diagnosis of asymptomatic Mycobacterium chelonae infections in a high proportion of the TU stock. Mycobacterium presents a zoonotic risk to fish handlers. In addition, the presence of underlying chronic disease in a model organism is unacceptable. The TU stock was depopulated and replaced by a new import of TU with the intent of reducing disease prevalence. In the current study, we sampled the new population of TU and fish of the AB, Tupfel long-fin (TL), TAB5 and TAB14 (2 AB × TU hybrid lines), and wildtype-in-Kalkutta (WIK) lines for histologic evaluation and acid-fast staining and compared the prevalence of subclinical mycobacteriosis between these lines. Although prevalence in the new TU stock was lower than that of the original TU stock, asymptomatic infections with Mycobacterium remained high (10%) in the new TU stock held in 20-gal tanks. The prevalence was similar (10%) in the TAB5 line compared with other wildtype lines held in similar conditions. Prevalence of infections in TU can be minimized by husbandry adjustments, including tank size, population density, and cleaning method. Application of these findings has allowed us to decrease mycobacteriosis in TU zebrafish and resume shipment of TU adults to the research community.

Ab-induced ectodomain shedding mediates hepatocyte growth factor receptor down-regulation and hampers biological activity

Targeting tyrosine kinase receptors (RTKs) with specific Abs is a promising therapeutic approach for cancer treatment, although the molecular mechanism(s) responsible for the Abs' biological activity are not completely known. We targeted the transmembrane RTK for hepatocyte growth factor (HGF) with a monoclonal Ab (DN30). In vitro, chronic treatment of carcinoma cell lines resulted in impairment of HGF-induced signal transduction, anchorage-independent growth, and invasiveness. In vivo, administration of DN30 inhibited growth and metastatic spread to the lung of neoplastic cells s.c. transplanted into immunodeficient nu/nu mice. This Ab efficiently down-regulates HGF receptor through a molecular mechanism involving a double proteolytic cleavage: (i) cleavage of the extracellular portion, resulting in "shedding" of the ectodomain, and (ii) cleavage of the intracellular domain, which is rapidly degraded by the proteasome. Interestingly, the "decoy effect" generated by the shed ectodomain, acting as a dominant negative molecule, enhanced the inhibitory effect of the Ab.

The major subunit ClpG of Escherichia coli CS31A fibrillae as an expression vector for different combinations of two TGEV coronavirus epitopes

Previously, two B-cell epitopes from the entero-pathogenic transmissible gastroenteritis virus (TGEV), namely the C epitope (TGEV-C) amino acids (aa) 363-371 and the A epitope (TGEV-A) aa 522-531 of the spike S protein (TGEV-S), have been separately expressed on the CS31A fibrillae at the surface of Escherichia coli following insertion into a same region of ClpG. However, the resulting chimeras induced a marginal TGEV-neutralizing antibody (Ab) response in mice. Here, with the view to improving this response, we introduced TGEV-C alone or in different tandem association with TGEV-A (A::C or C::A) in twelve putatively exposed regions of ClpG. Among the 28 resulting engineered proteins only 15, carrying up to 51 extra aa, had not essentially disturbed the correct CS31A fibrillae formation process. Six partially permissive sites accepting only TGEV-C and three highly permissive sites tolerating A::C or C::A tandem peptide, were identified throughout ClpG. Intact bacteria or extracted CS31A hybrid fibrillae expressing TGEV epitopes at any of the permissive sites, were recognized by Ab directed against the foreign parent protein, providing a direct argument for exposure of the corresponding CIpG region at the cell surface and for antigenicity of the epitopes in the polymeric CS31A fibrillae context. The potential of CS31A fibrillae as carriers of the TGEV peptides indicates that there may be three positions (N terminus, aa 202-204 and 202-218) in ClpG which may turn out to be important fusion sites and therefore be relevant for the eventual design of TGEV vaccines. Unexpectedly, TGEV-A, whatever its position in ClpG, mediated the partial proteolytic degradation of the hybrid proteins, suggesting that it functions as a substrate for a cellular protease, and thereby that its suitability as a vaccine antigen candidate is doubtful.